DRC-2025-000080

Deq submit <[e-mail]>
Fwd: CD-2025-001: (Exhibit 2) - Request for Additional Information: Disposal of
Radiological Wastes from the Dugway Proving Ground (DPG) Solid Waste
Management Unit (SWMU)-11 Area 2 Remedial Action
1 message
LLRW DWMRC <[e-mail]>Mon, Jan 6, 2025 at 6:07 AM
To: Deq submit <[e-mail]>
DRC
---------- Forwarded message ---------
From: Vern C. Rogers <[e-mail]>
Date: Fri, Jan 3, 2025 at 12:54 PM
Subject: CD-2025-001: (Exhibit 2) - Request for Additional Information: Disposal of Radiological Wastes from the Dugway
Proving Ground (DPG) Solid Waste Management Unit (SWMU)-11 Area 2 Remedial Action
To: Schwab, Kristen (DOH) <[e-mail]>
Cc: Karen Kirkwood <[e-mail]>, Kristina M. Garcia <[e-mail]>, Tab
Brown <[e-mail]>, Doug Hansen <[e-mail]>, LLRW DWMRC <[e-mail]>, Greg
T. Bright <[e-mail]>
Dear Ms. Schwab,

Earlier today, EnergySolutions is responding to your request for information regarding the U.S. Army Corps of Engineers’
(USACE) efforts to obtain authorization for the disposal of radiological wastes from DPG SWMU-11 at EnergySolutions’
Clive Facility.

You requested copies of two reports. The first was included as an exhibit in the response letter. Due to the size of the
second report, it is hereto attached separately as an additional exhibit to the same letter.

Should you have any questions or require further information to complete your review of USACE’s request, please do not
hesitate to contact me by phone at 801-649-2253 or by email at [e-mail]. I plan to follow up with
you by phone on Monday, January 6, 2025.

Sincerely,

Vern C. Rogers | ENERGYSOLUTIONS
299 South Main Street, Suite 1700
Salt Lake City, UT 84111

PHONE: [phone]
DIRECT: 801.649.2253
MOBILE: [phone]
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FACSIMILE: 801.880.2879
EMAIL: [e-mail]

CONFIDENTIALITY NOTICE: This electronic message transmission contains informaon from the firm of ENERGYSOLUTIONS, which is confidenal and privileged,
in accordance with Utah Code 63G-2-309. The informaon is intended to be for the use of the individual or enty named above. If you are not the intended
recipient, be aware that any disclosure, copying, distribuon or use of the contents of this informaon is prohibited. If you have received this electronic
transmission in error, please nofy me by telephone [phone]) or by electronic mail ([e-mail]) immediately. Nothing herein or in
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ML20230A320.pdf
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Final
Feasibility Study
Area 2 of SWMU-11
Dugway Proving Ground,
Dugway, Utah
Prepared for:
U.S. Army Environmental Command
Prepared by:
North Wind Services, LLC
August 2020 Rev. 0

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RPT-020121-002 Rev. 0
Final
Feasibility Study Area 2 of SWMU-11
Dugway Proving Ground
Dugway, Utah

August 2020
Prepared for: U.S. Army Environmental Command 2455 Reynolds Rd JBSA Fort Sam Houston, Texas 78234
Prepared by: North Wind Services, LLC. 1425 Higham Street Idaho Falls, Idaho 83402

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Review Comments and Responses 13 July 2020
1
Draft Final Feasibility Study Area 2 of SWMU 11, Dugway Proving Ground, Dugway, Utah W9124J-18-D-0007, Delivery Order W9124J18F0088 November 2019
1. Respondent concurs (C) or does not concur (D). 2. Commenter agrees (A) or does not agree (D) with response.
NUMBER PAGE SECTION COMMENT C, D RESPONSE A, D
Reviewer #1: Christopher Grossman, Project Manager, Low-Level Waste and Projects Branch, NRC (transcribed from letter dated 1 July 2020)
1 27-28, 7 and 9
Comment: Institutional Controls The Army should provide additional description of the legally enforceable institutional controls that
would be relied upon to ensure requirements in 10 CFR20.1403(b) for sites or portions of the sites that will be released for restricted use would be met should land use controls be selected as remedial actions to meet the remedial action objectives for the option of
unrestricted release. Description: Section 7 of the Army’s draft feasibility study report identifies several potential general response actions being considered to meet the Army’s remedial
action objectives and evaluates them against specific screening criteria, including effectiveness, implementability, and cost, to determine which actions should be used in the development of the remedial alternatives. The Army identifies and evaluates land use
controls (LUCs) as a potential general response action and indicates that LUCs can include institutional controls and engineered controls to limit activities at the Area 2 of SWMU-11.
C
Additional language has been added to Sections 7 and 9 to address legally enforceable institutional controls (ICs) at DPG. The following modifications were made to the text:
• Additional language has been added to Sections 7.2.3 and 9.2.2 to specifically address DPG as an active military installation and the authority of the Garrison Manager to enforce and regulate ICs. Enforceable restrictions will be incorporated into the Base Master Plan.
• Wording in Section 9.2.2 has been modified to clarify that DPG encompasses Area 2 of SWMU 11, and also trenches TR-5 and TR-6,
which are currently owned and operated by the DOD.
• The fencing discussion of 3 to 5 strand wire has been modified to 3-strand wire. Three-strand wire will ensure predators can access the area and control burrowing animals in the soil.

Review Comments and Responses 13 July 2020
2
NUMBER PAGE SECTION COMMENT C, D RESPONSE A, D
Reviewer #1: Christopher Grossman, Project Manager, Low-Level Waste and Projects Branch, NRC (transcribed from letter dated 1 July 2020)
Further, the Army identifies governmental
controls, enforcement tools, and informational devices as potentially feasible groups of administrative institutional controls, whereas, engineering controls include fencing to restrict physical access to Area 2. From this identification and screening evaluation, the
Army identifies land use controls as a remedial action alternative in Section 8 of the draft feasibility study report for further detailed analysis in Section 9. In the description of land use controls, the Army indicates that fencing and signage would be the primary
land use controls at Area 2, but does indicate, in Section 9.2.2, that Dugway Proving Ground is currently owned and operated by the DoD. NRC’s criteria for restricted release of sites, specified at 10 CFR 20.1403, requires, in
paragraph (b), that provisions for legally enforceable institutional controls that provide reasonable assurance that the dose from residual radioactivity distinguishable from background to the average member of the critical group will not exceed 25 mrem
(0.25 mSv) per year. The Army should ensure that the final feasibility study report describes provisions for legally enforceable institutional controls, and if LUCs are ultimately selected
as a remedial action, that the provisions for legally enforceable institutional controls be
clearly described in a future Land Use Control Implementation Plan.
• Discussion has been added to the Implementability portion of 9.2.2 to
state that prior to implementation, legally enforceable ICs will be fully defined in the Remedial Design and detailed in the LUCIP. Similar updates have been made to Section 9.2.3 where applicable to LUCs. Table 8
and Appendix E have been modified to reflect these updates.
Review Comments and Responses 13 July 2020
3
NUMBER PAGE SECTION COMMENT C, D RESPONSE A, D
Reviewer #1: Christopher Grossman, Project Manager, Low-Level Waste and Projects Branch, NRC (transcribed from letter dated 1 July 2020)
Basis: The NRC-DoD MOU requires that the
U.S. Army’s remedy at Dugway Proving Ground is consistent with the NRC’s requirements in 10 CFR20.1403(b) for sites or portions of the sites that will be released for restricted use. To be consistent with NRC’s criteria specified at 10 CFR20.1403(b), the
Army must make provisions for legally enforceable institutional controls that provide reasonable assurance that the dose from residual radioactivity distinguishable from background to the average member of the critical group will not exceed 25 mrem
(0.25 mSv) per year.

Review Comments and Responses 13 July 2020
4
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Final Feasibility Study iii North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
CONTENTS
EXECUTIVE SUMMARY .......................................................................................................................... 1
INTRODUCTION ........................................................................................................................... 3
1.1 Purpose and Organization of Report ................................................................................... 3
1.2 Background Information ..................................................................................................... 4
1.2.1 Site History ............................................................................................................. 4
1.2.1 Previous Investigations ........................................................................................... 4
NATURE AND EXTENT OF CONTAMINATION .................................................................... 11
2.1 TR-5 COC Extent and Characteristics .............................................................................. 11
2.2 TR-6 COC Extent and Characteristics .............................................................................. 11
CONTAMINANT FATE AND TRANSPORT ............................................................................. 15
3.1 Soil .................................................................................................................................... 15
3.2 Groundwater ..................................................................................................................... 15
DERIVED CONCENTRATION GUIDELINES AND RADIOLOGICAL CONTAMINANTS OF CONCERN ............................................................................................. 17
HUMAN AND ECOLOGICAL RECEPTORS AND EXPOSURE ROUTES ............................. 19
REMEDIAL ACTION OBJECTIVES, REQUIREMENTS, AND REMEDIAL GOALS ........... 21
6.1 Remedial Action Objectives ............................................................................................. 21
6.2 Applicable or Relevant and Appropriate Requirements ................................................... 21
6.2.1 Chemical-Specific ................................................................................................. 21
6.2.2 Location-Specific .................................................................................................. 22 6.2.3 Action-Specific ..................................................................................................... 22
6.3 Development of Derived Concentration Guideline Levels as Remedial Goals ................ 23
6.3.1 Chemical-Specific ARAR Applicability ............................................................... 23
IDENTIFICATION AND SCREENING OF REMEDIAL TECHNOLOGIES............................ 25
7.1 General Response Actions ................................................................................................ 25
7.2 Identification and Screening of Remedial Technologies and Process Options ................. 25
7.2.1 Identification of Technologies .............................................................................. 25 7.2.2 Screening Criteria ................................................................................................. 25
7.2.3 Evaluation of GRAs, Remedial Technologies, and Process Options .................... 26 7.2.4 Selection of Remedial Technologies and Process Options ................................... 29

Final Feasibility Study iv North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
DEVELOPMENT OF REMEDIAL ALTERNATIVES ............................................................... 31
8.1 Development of Remedial Alternatives for Radiological Contaminants of
Concern in Soil ................................................................................................................. 31
8.1.1 Alternative 1: No Action ....................................................................................... 31 8.1.2 Alternative 2: Land Use Controls ......................................................................... 31 8.1.3 Alternative 3: Capping .......................................................................................... 31 8.1.4 Alternative 4: Excavation, Disposal, and Backfilling ........................................... 32 8.1.5 Alternative 5: Excavation, Sorting, Screening, and Disposal ............................... 33 8.1.6 Alternative 6: Soil Stabilization ............................................................................ 33
DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES .................................................... 35
9.1 Evaluation Criteria ............................................................................................................ 35
9.1.1 Threshold Criteria ................................................................................................. 35 9.1.2 Balancing Criteria ................................................................................................. 36
9.1.3 Modifying Criteria ................................................................................................ 37
9.2 Individual Alternative Analysis ........................................................................................ 37
9.2.1 Alternative 1 – No Action ..................................................................................... 37
9.2.2 Alternative 2 – Land Use Controls ....................................................................... 38 9.2.3 Alternative 3 - Capping ......................................................................................... 40 9.2.4 Alternative 4 – Excavation, Disposal, and Backfilling ......................................... 42 9.2.5 Alternative 5 – Excavation, Sorting, Screening, and Disposal ............................. 44 9.2.6 Alternative 6 – Soil Stabilization .......................................................................... 46
9.3 Comparative Alternative Analysis .................................................................................... 48
9.3.1 Overall Protection of Human Health and the Environment .................................. 48 9.3.2 Compliance with Applicable or Relevant and Appropriate Requirements ........... 48 9.3.3 Long-Term Effectiveness and Permanence .......................................................... 48 9.3.4 Reduction of Toxicity, Mobility, Volume, and Mass ........................................... 49 9.3.5 Short-Term Effectiveness ..................................................................................... 49 9.3.6 Implementability ................................................................................................... 49 9.3.7 Cost ....................................................................................................................... 50
SUMMARY AND CONCLUSION .............................................................................................. 51
REFERENCES .............................................................................................................................. 53
FIGURES
Figure 1. Site Location .................................................................................................................................. 5
Figure 2. Site Layout ..................................................................................................................................... 6
Figure 3. TR-5 and TR-6 Plan View 2016 Investigation ............................................................................ 13
Figure 4. TR-5 Cross Sections, 2016 Investigation .................................................................................... 14

Final Feasibility Study v North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
TABLES
Table 1. TR-5 and TR-6 2005 Phase II Investigation Results. ................................................................... 57
Table 2. TR-6 Maximum Radionuclide Soil Concentrations. ..................................................................... 59
Table 3. TR-5 Maximum Radionuclide Soil and Debris Concentrations. .................................................. 59
Table 4. Soil DCGLs for Unrestricted (Residential) Use. .......................................................................... 59
Table 5. Soil DCGLs for Restricted (Industrial) Use. ................................................................................. 60
Table 6. Evaluation of General Response Actions, Remedial Technologies, and Process Options. .......... 61
Table 7. Alternatives Summary and Evaluation Comparison. .................................................................... 63
Table 8. Cost Analysis of Remedial Alternatives. ...................................................................................... 65
APPENDICES
Appendix A Characterization Report (included on CD)
Appendix B Ecological Risk Screening
Appendix C MicroShield Modeling
Appendix D Exposure Rate Reduction Modeling
Appendix E Cost Estimate Evaluation

Final Feasibility Study vi North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
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Final Feasibility Study vii North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
ACRONYMS AND ABBREVIATIONS
µR/hr microroentgen per hour
AEC Army Environmental Command
ALARA as low as reasonably achievable
ARAR Applicable or Relevant and Appropriate Requirements
BCG biotic concentration guidelines
bgs below ground surface
CERCLA Comprehensive Environmental Response, Compensation and Liability Act
CFR Code of Federal Regulations
COC contaminant of concern
cpm counts per minute
CY cubic yards
DCGL Derived Concentration Guideline Level
DD Decision Document
DoD Department of Defense
DOE Department of Energy
DPG Dugway Proving Ground
DWMRC Utah Division of Waste Management and Radiation Control
EPA United States Environmental Protection Agency
FIDLER Field Instrument for the Detection of Low Energy Radiation
FS Feasibility Study
ft feet
ft2 square feet
GCL Geosynthetic clay liner
GM Geiger Mueller
GPR ground penetrating radar
GRA General Response Action
HDPE high-density polyethylene
IC Institutional Control

Final Feasibility Study viii North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
LTM long-term maintenance
LUC land use control
LUCIP Land Use Control Implementation Plan
MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual
mg/kg milligrams per kilogram
mg/L milligrams per liter
MoU Memorandum of Understanding
mrem/yr millirem per year
NCP National Contingency Plan
North Wind North Wind Services, LLC
NRC U.S. Nuclear Regulatory Commission
O&M Operations and Maintenance
OMB Office of Management and Budget
pCi/g picocuries per gram
PP Proposed Plan
RACER® Remedial Action Cost Engineering and Requirements
RAO Remedial Action Objective
RCRA Resource Conservation and Recovery Act
RESRAD Residual Radioactivity
RFI RCRA Facility Investigation
RI Remedial Investigation
SVOC semi-volatile organic compound
SWMU Solid Waste Management Unit
TCLP Toxicity characteristic leaching procedure
TR trench
U.S. United States
UU/UE Unrestricted Use/Unrestricted Exposure
VOC volatile organic compound

Final Feasibility Study 1 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
EXECUTIVE SUMMARY
This Final Feasibility Study (FS) was prepared for Area 2 of Solid Waste Management Unit 11 (SWMU-11) at the Dugway Proving Ground (DPG) in Dugway, Utah in accordance with the
Performance Work Statement for the United States Army Environmental Command (AEC) under Contract No. W9124J-18-D-0007, Delivery Order W9124J18F0088.
Area 2 of SWMU-11 at DPG is a radiological disposal area of concern located at DPG. DPG is in western
Utah and covers approximately 840,000 acres in Tooele County. Records indicate Area 2 was never licensed by the U.S. Nuclear Regulatory Commission (NRC). During 2016, the Department of Defense (DoD) and the NRC finalized a memorandum of understanding (MoU) for the coordination of response actions for DoD sites containing radioactive material that are not licensed by the NRC (NRC-DoD MoU, 2016). This FS is prepared pursuant to the MoU and the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of 1986, to the extent practicable the National Contingency Plan (NCP), U.S. Environmental Protection Agency (EPA) Remedial Investigations (RI)/FS Guidance 540/G-89/004 (EPA, 1988), and is part of the overall remedial action process.
The nature and extent of contamination were initially identified in trenches TR-5 and TR-6 of Area 2 SWMU-11 in the 2005 Phase II Resource Conservation and Recovery Act (RCRA) Facility Investigation
(RFI) for SWMU-11 (Parsons, 2009) and the 2014 RI/FS (Cabrera, 2014) and 2016 Final Report (Cabrera, 2016). Contaminants of concern (COCs) and excavation waste volumes were calculated by Cabrera. This data was re-evaluated and defined by North Wind Services, LLC (North Wind) to
determine the radiological COCs in the site Characterization Report (North Wind, 2019), which is included as Appendix A. The nature and extent and fate and transport are summarized in Sections 2 and 3, respectively, of this report.
Six remedial alternatives are presented in this FS and are developed, screened, and evaluated to address the site-related contaminants that were determined to pose an unacceptable risk to human health and the environment. These six remedial alternatives are:
1. No Action;
2. Land Use Controls (LUCs);
3. Containment through capping;
4. Excavation, Disposal, and Backfilling;
5. Excavation, Sorting, Screening, and Disposal; and
6. Soil Stabilization
Effectiveness, implementability, and cost are used to screen these six alternatives and to select which alternatives are carried forward in the Feasibility Study. Closure standards, including NRC standards
10 CFR 20.1402 and 10 CFR 20.1403, are addressed in this FS. Evaluation criteria, including overall protection of human health and the environment; compliance with chemical-, location-, and action-specific applicable or relevant and appropriate requirements (ARARs); long- and short-term
effectiveness; reduction of toxicity, mobility, volume, and mass of contamination; implementability; and cost, were used to evaluate each remedial alternative in an individual and comparative analysis. The results of that analysis are presented herein.

Final Feasibility Study 2 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
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Final Feasibility Study 3 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
INTRODUCTION
DPG is located in western Utah on approximately 840,000 acres in southern Tooele County (Figure 1). The facility is bordered to the northeast by the Cedar Mountains and to the north-northwest by Wendover
Air Force Range. DPG currently serves as the Army’s designated Major Range Test Facility for chemical and biological defense.
SWMU-11, also known as DPG-011 and the East Granite Holding Area, is located in the remote
southwest portion of DPG and lies within a small canyon on the east side of Granite Mountain. SWMU-11 is divided into two distinct areas: Area 1 and Area 2. Area 1 of SWMU-11 consists of three closed trenches (TR-1, TR-2, and TR-3) running roughly east-west along the north side of the canyon and a fourth backfilled trench (TR-4) running north-south. Area 1 of SWMU-11 was previously evaluated and closed under RCRA and corrective action requirements of the Utah Division of Waste Management and Radiation Control (DWMRC). Area 2 (0.86 acres) of SWMU-11 is a radiological disposal area of concern and consists of two trenches (TR-5 and TR-6) and the area adjacent to the trenches. Area 2 previously contained a CONEX container; however, it was determined to be radiologically clear and was removed in 2017 (Marsh, 2017). This FS specifically addresses Area 2 of SWMU-11. Figure 2 shows the Area 2
boundary and trench locations.
Area 2 of SWMU-11 at DPG is a radiological disposal area of concern that records indicate was never
licensed by the NRC. During 2016, the DoD and the NRC finalized a MoU for the coordination of response actions for DoD sites containing radioactive material that are not licensed by the NRC (NRC-DoD MoU, 2016). This FS is prepared pursuant to the MoU and CERCLA, as amended by the Superfund
Amendments and Reauthorization Act of 1986, to the extent practicable the NCP, EPA RI/FS Guidance 540/G-89/004 (EPA, 1988), and is part of the overall remedial action process.
1.1 Purpose and Organization of Report
The FS report serves as the mechanism for the development, screening, and detailed evaluation of remedial action alternatives to address site-related contaminants that pose an unacceptable risk to human health or the environment. Remedial actions that reduce or eliminate the threat, while complying with ARARs and satisfying the other criteria established in CERCLA §121 (b)(1), were developed, screened, and evaluated
to support risk management decisions.
This FS report is organized into 11 sections:
• Section 1 provides an introduction to the report and site background information, including the site history and previous investigations,
• Section 2 discusses nature and extent of contamination,
• Section 3 discusses contaminant fate and transport,
• Section 4 identifies the radiological COCs and the development of Derived Concentration Guideline Levels (DCGLs),
• Section 5 identifies human and ecological receptors and exposure routes,
• Section 6 identifies and discusses the RAOs, ARARs, and remedial goals.

Final Feasibility Study 4 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
• Section 7 identifies and discusses the development of general response actions, and the screening of remedial alternatives.
• Section 8 provides a discussion of the development of remedial alternatives.
• Section 9 provides a detailed analysis and comparison of remedial alternatives using evaluation criteria.
• Section 10 presents a summary and conclusion of the FS.
• Section 11 presents the references cited herein.
1.2 Background Information
1.2.1 Site History
In the DPG RCRA Facility Application, SWMU-11, Area 2, was one of seven reported radioactive landfills. Historic records regarding radiological materials handling were summarized in the 2009 Phase II RFI (Parsons, 2009). Specific records regarding radiological materials disposed at SWMU-11 are limited. The East Granite Holding Area (i.e., SWMU-11) is not identified in the available literature as being associated with the testing of radiological munitions conducted at DPG in the 1950s and 1960s. Historical inspection records indicate that buried wastes in the SWMU-11 area consisted primarily of “contaminated rags and papers.” Inspection records from the U.S. Atomic Energy Commission indicate that low-level radioactive waste materials were repackaged for sea disposal in the Able Area. Waste from this activity
may have also been disposed at the DPG burial area corresponding to SWMU-11 after the sea disposal program was discontinued.
Radioactive waste materials from laboratory activities in other areas of DPG were stored in a CONEX
container at SWMU-11 to protect individual storage containers from the elements (Figure 2). Materials stored in the CONEX container included Tritium and Carbon-14. In March 1980, contaminated glassware was removed from the CONEX by the DPG radiation safety officer and disposed at an off-site location. During the 2005 Phase II investigation, no waste remained in the CONEX container (Parsons, 2009). The CONEX container was determined to be radiologically clear and was removed in 2017 (Marsh, 2017).
In June 2000, DPG notified the NRC about potential radiological waste at SWMU-11. During a limited survey of the area conducted in September 2000, NRC personnel were unable to detect any radioactivity significantly above background levels. In March 2001, the NRC stipulated that any required decommissioning activities at SWMU-11 could take place under the radioactive materials license currently held by DPG. However, in March 2006, the NRC notified DPG that the NRC would evaluate if a new license was necessary to conduct decommissioning activities; no new license was issued. The current radioactive materials license was for possession of sealed sources associated with an irradiator. During 2016, the DoD and the NRC finalized a MoU for the coordination of response actions for DoD sites with radioactive materials that are not licensed by the NRC (NRC-DoD MoU, 2016). Pursuant to the
MoU, the remaining investigation and remediation activities at Area 2 of SWMU-11 are being addressed under CERCLA.
1.2.1 Previous Investigations
The following is a brief description of previous investigations conducted to establish COCs which define the current nature and extent of contamination at Area 2 of SWMU-11.

Final Feasibility Study 5 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020

Figure 1. Site Location

Final Feasibility Study 6 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020

Figure 2. Site Layout

Final Feasibility Study 7 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
2005 Phase II Investigation
While investigating TR-1 through TR-4 and the surrounding area with geophysical and radiological scans
during the 2005 Phase II RFI of SWMU-11 (Parsons, 2009), two additional burial trenches on the west side of TR-4 were discovered and subsequently designated as TR-5 and TR-6. The area was designated as Area 2. The following activities and samples were collected from the two trenches as part of the
investigation:
• A magnetometer survey;
• A radiological survey using scanning and direct measurements;
• Four surface soil samples (0 to 0.5 feet [ft] below ground surface [bgs]) collected from TR-5;
• Two surface soil samples (0 to 0.5 ft bgs) collected from TR-6;
• One material sample collected that included metal remnants of drum material from TR-5;
• One material sample collected that included solidified sand from inside a corroded drum (approximately 2 ft bgs) from TR-6;
• One soil sample collected from the base of the test pit (10 ft bgs) to investigate potentially buried wastes in TR-6; and
• One soil boring drilled and one subsurface soil sample collected to characterize subsurface soil downgradient of Area 2.
Results of the 2005 Phase II investigation are presented on Table 1. The magnetometer survey identified anomalies in both TR-5 and TR-6; anomalous radioactivity was also measured in TR-5 and TR-6. At TR-5, surface scans identified an area of highly elevated radiological activity that was conspicuously devoid of vegetation and marked by a slight topographic depression (Parsons, 2009). Gamma exposure rate measurements ranged from 420 microroentgen per hour (µR/hr) at the center of TR-5 to 50 µR/hr at approximately 3 ft from center, and 30 µR/hr at approximately 6 ft from center. Additional field measurements collected with a Field Instrument for the Detection of Low Energy Radiation (FIDLER) and a Geiger Mueller (GM) pancake probe, which measure gamma and beta radiation, respectively,
produced readings between 1,200 counts per minute (cpm) and 575,000 cpm directly over the area, and readings between 75 cpm and 28,000 cpm for background levels. The soil over the anomalously elevated area was not radioactive itself but was instead covering buried radioactive waste material. Analytical
results from surface and subsurface soil samples collected from TR-5 revealed a single detection of Strontium-90 (4.4 picocuries per gram [pCi/g]). The metallic remnants from drum material, collected from 0.25 ft bgs, indicated gamma spectroscopic characteristics similar to those of the surface anomaly.
The metallic remnant was concluded to be a ferrous metal contaminated with Strontium-90. However, the source, depth, and quantity of material was not determined (Parsons, 2009).
At TR-6, the test pit excavation identified various types of debris, including small metal tubes from approximately 7 ft bgs that had low levels of radioactivity with signatures consistent with Cesium-137. Other types of debris, including the metal drums with solidified sand and drum cores, did not exhibit detectable levels of radioactivity. Soils underlying these materials were screened for radiation during test pit excavation and were detected at background radiation levels. However, due to the uncertainties associated with the contents of the metallic cylinders, they were not shipped for laboratory analyses. Thus, in the absence of more conclusive laboratory analysis, the waste in TR-6 was considered unidentified.

Final Feasibility Study 8 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Additionally, non-radiological chemical results included detections of metals, semi-volatile organic compounds (SVOCs), and dioxins/furans at TR-5 and TR-6. In subsequent evaluations, these non-
radiological chemical results were determined not to be COCs. Groundwater sampling results from SWMU-11 were also used to assess potential impacts to groundwater by site-related contamination. Groundwater samples were analyzed for volatile organic compounds (VOCs), perchlorate metals, water quality analytes, gross alpha, gross beta, gamma spectrometry, and Strontium-90; no unusual results were detected. Further investigation of the radiological portion of Area 2 at SWMU-11 was recommended in the Phase II RFI.
2014 Investigation
In 2014, Cabrera performed a non-intrusive (i.e., surface scanning) investigation at Area 2 of SWMU-11 using surficial gross gamma radiological scans and geophysical (a hand-held Schondstedt magnetometer and ground penetrating radar [GPR]) scans, as identified in the RI/FS Work Plan. The Schondstedt magnetometer and GPR investigation defined the lateral and vertical extent of TR-5 and TR-6. An area of
approximately 440 square feet (ft2) (approximately 2 ft of soil cover and approximately 4 ft in depth below the covering soil) was delineated at TR-5. The radiological scans detected surface gamma emitting radioactive material at TR-5, with maximum detections in the southern half of the trench.
At TR-6, however, the GPR scan did not penetrate through the salty soil. Instead, a visual inspection detected surface debris consisting of metal tubes and possible soil piles approximately 1 to 1-½ ft high by 8 to 10 ft long. Buried metal was detected with the Schondstedt magnetometer in these low soil mounds,
suggesting that debris was spread out and then covered with a thin layer of soil with an approximate surface area of 12 ft by 16 ft.
This investigation served to confirm the Phase II surface scanning results. Though elevated readings were confirmed at TR-5, there were no indications of surface elevated gross gamma activity on or around TR-6 or outside of the TR-5 boundary based on the radiological investigation (Cabrera, 2014). No laboratory samples were collected during this investigation.
2016 Investigation
In 2016, Cabrera completed the intrusive portion of the investigation (as identified in the RI/FS Work Plan) using core scanning, downhole gamma logging, and collection of samples for confirmatory laboratory analytical testing. The investigation included 15 soil boring locations (10 at TR-5 and five at TR-6), 34 soil samples, and one debris sample.
Soil cores scanned with a GM pancake probe indicated radioactive contamination in TR-5 soils exceeded the established screening criteria at two borehole locations, SB-14 (0 to 1-ft interval) and SB-15 (0 to 1-ft and 1 to 2-ft intervals), in the southern half of the trench (Cabrera, 2016). Downhole gamma logging
using a sodium iodide detector confirmed that a majority of the radioactivity appeared to be within the top 3 or 4 ft of material at TR-5. However, elevated activities were identified in intervals below 4 ft bgs, and in some locations as deep as 8 ft bgs. At TR-6, only one borehole showed elevated radioactivity through
downhole gamma logging; all depths within the other four boreholes showed no indication of elevated radioactivity and all readings were less than 9,000 cpm. Borehole 10, located at the northern end of the TR-6 footprint, exhibited a downhole gamma logging result of 10,504 cpm between 5 to 6-ft bgs, and radioactivity greater than 9,000 cpm within the upper 6 ft bgs of material. This borehole was located directly adjacent to a known metal anomaly; thus, the elevated readings may be attributed to this.

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Laboratory analytical results detected concentrations of Bismuth-214, Lead-214, Radium-226, and Strontium-90 at TR-5 from one to two orders of magnitude greater than concentrations in other borings.
While soil results did not exceed screening criteria in TR-6 (Cabrera, 2016), the six highest concentrations of Cesium-137 occurred in this trench. There were no exceedances for any chemical samples (i.e., VOCs, SVOCs, or metals) above the toxicity characteristic leaching procedure (TCLP) regulatory limits presented in 40 Code of Federal Regulations (CFR) 261.24. Therefore, it was concluded that it was unlikely that any wastes generated from the excavation of the trenches would result in hazardous or “mixed” waste.
North Wind conducted an additional review of the Phase II chemical data and noted an arsenic result of 155 milligrams per kilogram (mg/kg) from the TR-6 solidified sand from inside a drum. As a result, it was determined that TCLP analysis of the contents of drums within TR-6 may be warranted in future remedy implementation (North Wind, 2019).

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NATURE AND EXTENT OF CONTAMINATION
Radiological COCs help to define the current nature and extent of contamination at Area 2 of SWMU-11. The maximum radionuclide concentrations at TR-6 and TR-5 were obtained from data collected by
Cabrera (2016) and are presented in Tables 2 and 3, respectively.
2.1 TR-5 COC Extent and Characteristics
Based on the 2016 investigation, downhole gamma logging results generally support laboratory results at TR-5. Maximum concentrations of Radium-226 (3,040 pCi/g), Strontium-90 (19.2 pCi/g), Bismuth-214
(2,100 pCi/g), Niobium-94 (8.9 pCi/g), and Lead-214 (2,200 pCi/g) were reported at the 0 to 1-ft interval at SB-15. Radiological screening conducted after excavating to 1 ft bgs in three locations showed elevated gamma readings, indicating that radiological contamination was relatively homogeneous. Overall, field
screening and laboratory results indicate that COCs at TR-5 are elevated within the trench, with detections exceeding background in surface and subsurface soil and the highest concentrations in the surface intervals at SB-14 and SB-15. The lateral and vertical extent of TR-5 are depicted in Figures 3 and 4, respectively, using downhole gamma logging data collected during the 2016 investigation by Cabrera. The inferred extent of impact (Cabrera, 2016) at TR-5 is depicted in Figure 3. A cross-section view of TR-5 is depicted in Figure 4.
2.2 TR-6 COC Extent and Characteristics
Field scanning results at TR-6 did not indicate any substantially elevated radioactivity at land surface, and laboratory soil results were uniform, with no particular sample results greatly exceeding others.
Cesium-137 was initially identified during the Phase II investigation from a debris sample taken from the
small metal tubes identified at 7 ft bgs during the excavation of test pit EP-15. During the 2016 sample collection, five soil samples had Cesium-137 concentrations greater than those documented in TR-5, despite concentrations that were less than the dose compliance concentration screening levels. Downhole gamma logging identified a slightly elevated result at one location that was likely associated with a metal anomaly detected during the geophysical survey. Based on the available data, it was determined that the metallic debris in TR-6 may contain Cesium-137, particularly in the areas where geophysical anomalies were identified. The inferred lateral extent of impact at TR-6 is depicted in Figure 3, using downhole gamma logging data collected during the 2016 investigation (Cabrera, 2016).

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Figure 3. TR-5 and TR-6 Plan View 2016 Investigation

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Figure 4. TR-5 Cross Sections, 2016 Investigation

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CONTAMINANT FATE AND TRANSPORT
3.1 Soil
Soil in Area 2 of SWMU-11 is known to contain Radium-226, Strontium-90, Bismuth-214, Niobium-94, Lead-214, and may contain Cesium-137, as described in Sections 2.1 and 2.2. Radiological constituents in soil could be transported via wind or water erosion, could be redistributed via burrowing animals, and could be assimilated into the food chain via plant uptake or direct ingestion by animals. In addition, constituents in soil could leach and migrate towards the water table as precipitation percolates through the
trenches. The Characterization Report (Appendix A) used the Residual Radioactivity (RESRAD) ONSITE computer code (Department of Energy [DOE], 2004) to model the various potential transport and human exposure pathways for soil COCs under both a residential and an industrial land use scenario.
Debris in TR-6, identified as small metal tubes with signatures of Cesium-137, were never shipped for laboratory analysis due to the uncertainty associated with the contents. As a result, the waste in TR-6 is considered unidentified. Despite these “sealed” radioactive sources, the possibility of a leak due to aging,
an accident, damage, or poor manufacture, could cause releases or migration of radioactive contamination in TR-6.
3.2 Groundwater
Groundwater in the area of SWMU-11 is part of the Dugway Valley aquifer system and is generally
characterized by high total dissolved solids and flat hydraulic gradients. The flanks of Granite Mountain (including the SWMU-11 site) constitute a local recharge zone for basin groundwater in which groundwater is deeper and of higher quality than groundwater beneath the basin floor. As groundwater
flows from the local recharge area toward the basin floor, it becomes increasingly laden with dissolved mineral constituents, and the quality of groundwater is greatly diminished. Thus, due to the overall low quality of groundwater in the western DPG region, there have been no potable water resources developed in the Granite Mountain area. Localized water wells provide water only for dust suppression, hand washing, and toilet flushing purposes at the U.S. Air Force Strategic Training Range Complex. Groundwater quality at SWMU-11 is Class II (drinking water quality) per Utah Administrative Code R317-6-3 (DWQ, 2019), based on the laboratory total dissolved solids measurement of 1,770 milligrams per liter (mg/L) from the groundwater sample collected by Parsons (2009).
The groundwater pathway was evaluated for Area 2 of SWMU-11 using a Resident Farmer scenario. Conservative parameter values were used for the groundwater pathway, basing the parameter values for the unsaturated and saturated zones on the typical properties of sand. Results of the Residual Radioactivity (RESRAD) ONSITE computer code (DOE, 2004) show that the travel time of radionuclides to the aquifer for all radiological COCs of interest are greater than the 1,000-year model period. Therefore, radiological COCs will not migrate to the groundwater during the assessment period.
Evidence from the attempt by Parsons to install a groundwater monitoring well near SWMU-11, Area 2, indicates that the development of a water well in this area of the site may not be possible. Therefore, the groundwater pathway is not a significant contributor to the receptor doses at SWMU-11, Area 2, and is
not included in this FS.

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DERIVED CONCENTRATION GUIDELINES AND RADIOLOGICAL CONTAMINANTS OF CONCERN
DCGLs were developed for soil, consistent with 10 CFR Part 20, Subpart E, as referenced in the 2016 MoU (NRC-DoD MoU, 2016). Site-specific DCGLs were calculated for TR-5 and TR-6 using the RESRAD ONSITE computer code (DOE, 2004). A more complete discussion of this development can be
found in the Characterization Report (Appendix A).
The DCGLs were used to define radiological COCs for Area 2 of SWMU-11, as described in the
Characterization Report. The radiological COCs were then used to select a group of radionuclides and radionuclide decay chains that were modeled for the DCGLs for both TR-5 and TR-6. The following constituents were included as radiological COCs:
• C-14;
• Cs-137 + D (i.e., Ba-137m);
• Nb-94;
• Pb-210 + D (i.e., Bi-210, Po-210);
• Pu-242 + D (i.e. U-238 decay series);
• Ra-226 + D (i.e., Rn-222, Po-218, Pb-534 214, Bi-214, Po-214, Pb-210, Bi-210 and Po-210);
• Sr-90 + D (i.e., Y-90);
• Th-229 + D (i.e., Ra-225, Ac-225, Fr-221, At-217, Bi-213, Tl-209, Pb-209 and Po-213);
• Th-230 + D (i.e., Ra-226 decay series);
• Th-232 + D (i.e., Ra-228, Ac-228, Th-228, Ra-224, Rn-220, Po-216, Pb-212, Bi-212, Tl-208 and Po-212);
• U-232 + D (i.e., Th-228, Ra-224, Rn-220, Po-216, Pb-212, Bi-212, Tl-208 and Po-212);
• U-234 + D (i.e., Th-230 decay series);
• U-235 + D (i.e., Th-231, Pa-231, Ac-227, Fr-223, Ra-223, Rn-219, Po-215, Pb-211, Bi-211, Tl-207; Po-211 and Th-227); and
• U-238 + D (i.e., Th-234, Pa-234m, Pa-234 and U-234 decay series).
Two dose scenarios were developed using the DCGLs: (1) residential (i.e., unrestricted), which requires
no LUCs or long-term maintenance (LTM) based on 25 millirem per year (mrem/yr); and (2) industrial (i.e., restricted release), which occurs after loss of LUCs or LTM based on 100 mrem/yr. The RESRAD ONSITE computer model (Kamboj et al., 2018) was used for all modeling for the development of the
DCGLs. The Resident Farmer was selected as the critical group for DCGL development for unrestricted release under 10 CFR 20.1402. A Resident Farmer critical group results in more conservative DCGLs (i.e., lower concentrations) than an industrial use critical group due primarily to the increased dose from

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the consumption of food grown on-site and occupancy time considerations. An Industrial Worker was selected as the critical group for DCGL development for restricted release under 10 CFR 20.1403. The
Industrial Worker is considered representative of the likely future use of the Dugway site.
Soil
The Resident Farmer and Industrial Worker scenarios assume that the entire volume of contaminated soil in a trench is exhumed and spread over the ground surface, resulting in a 6-inch contaminated soil layer. This is a conservative assumption and provides a conservative estimate of the radionuclide DCGLs. Both TR-5 and TR-6 were classified consistent with guidance in the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) as Class 1 Areas, meaning both have a potential for radioactive contamination based on site operating history, or known contamination based on previous radiological
surveys. The buffer areas surrounding TR-5 and TR-6 were classified as Class 3 Areas, based on the radiological survey area and geophysical results indicating no surface radioactive material on or around TR-6 or outside of the TR-5 boundary.

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HUMAN AND ECOLOGICAL RECEPTORS AND EXPOSURE ROUTES
Radiological COCs in soil and debris pose the highest potential exposure for human and ecological receptors. As the groundwater pathway was previously determined to be an insignificant contributor to the receptor doses at Area 2 of SWMU-11, it does not pose a concern for potential exposure to human or ecological receptors.
Receptors with the highest potential to be exposed to radiological soil and debris COCs include site
industrial workers and ecological receptors. Area 2 of SWMU-11 does not currently house any administrative buildings, family housing, industrial facilities, or barracks, and no future construction projects or residential housing are planned for this area. Access to the site is restricted; therefore,
trespassers are not expected at the site under current conditions.
Based on information from DPG staff, current usage by a site industrial worker is estimated to be approximately 2 hours per day, 5 to 10 days per year. When present, industrial workers could potentially
contact impacted soil and debris. The industrial worker is considered representative of the likely future use at DPG and future land uses are anticipated to be consistent with the current land uses. Future potential contact with impacted soil and debris could include site inspections and maintenance activities. Though not identified as a current or immediate future receptor, the Resident Farmer or residential user may potentially encounter radiological COCs in the distant future.
Ecological receptors may also encounter radiological COCs in soil at TR-5 and TR-6. Current and future use by ecological receptors is expected to remain unchanged. Radiation exposure of terrestrial plants and animals was evaluated using the RESRAD-BIOTA computer model, a tool for implementing the DOE “Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota” (DOE, 2002). Based on the results of the RESRAD-BIOTA output, the only exceedance of the terrestrial animal biotic concentration guidelines (BCGs) was for the maximum soil concentrations of Ra-226 at TR-5
(3,040 pCi/g). However, it is highly unlikely that any population of animals would only be exposed to the maximum soil concentration. Therefore, the average soil concentration (136.6 pCi/g) is considered a better metric of the soil concentration to which the terrestrial animals would be exposed. Based on the
average soil concentrations at TR-5 and TR-6, the BCGs would not be exceeded. Further evaluation and results of the ecological risk screening are presented in Appendix B. This evaluation confirmed that there are no ecological COCs and therefore, remedial actions are not required to address ecological exposure
pathways.
Thus, humans are identified as the primary receptors at Area 2 of SWMU-11. The identified or potential exposure routes for human receptors for the site include:
• Direct radiation,
• Inhalation of re-suspended dust, and
• Direct ingestion of soil.

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REMEDIAL ACTION OBJECTIVES, REQUIREMENTS, AND REMEDIAL GOALS
The following sections discuss the development of RAOs, ARARs, and DCGLs as remedial goals.
6.1 Remedial Action Objectives
RAOs are site-specific, initial clean-up objectives that are established based on the nature and extent of contamination, the resources that are currently and potentially threatened, and the potential for human and ecological exposure. The purpose of the RAOs is to reduce the potential for radiological exposure, thereby limiting the dose to receptors.
The following RAOs were developed for the remediation of radiological soil and debris at Area 2 of
SWMU-11:
1. Prevent direct contact to or external exposure from contaminated soil and radiological debris
(i.e., metal tubes) by human receptors with consideration to current land uses and potential future land uses. Current and potential future receptors are identified as site industrial workers, resident farmers, and residential users.
2. Reduce the potential for migration of soil COCs to areas beyond the trenches (i.e., buffer zones surrounding the trenches, air, and groundwater).
6.2 Applicable or Relevant and Appropriate Requirements
This section describes the regulatory standards and guidance that may be applied to the remedial actions in accordance with 40 CFR 300.400(g). These regulatory standards and guidance requirements are divided into three categories: (1) chemical-specific, (2) location-specific, and (3) action-specific.
6.2.1 Chemical-Specific
Chemical-specific requirements establish health-based concentration limits, risk-based concentration limits, or ranges for specific hazardous substances in different environmental media. These standards provide media cleanup levels or a basis for calculating cleanup levels for COCs. Chemical-specific
standards are also used to indicate an acceptable level of discharge to determine treatment and disposal requirements for a particular remedial activity, and to assess the effectiveness of a response action. The potential chemical-specific ARARs identified for remedial action at the site include Radiological Criteria
for Unrestricted Use (Residential) (10 CFR 20.1402) and Criteria for License Termination Under Restricted Conditions (Industrial) (10 CFR 20.1403). The COCs at Area 2 of SWMU-11 are radiological COCs. Arsenic was not identified as a COC and is not driving the remedial alternatives development. The ARARs for waste characterization are adequate and appropriate to address the uncertainty regarding the single elevated detection of arsenic. Specifically, prior to off-site disposal, any excavated material would be subjected to TCLP analysis to confirm it meets the landfill criteria for acceptance.
Additional chemical-specific ARARs may include:
• 40 CFR 262.11(a), (b), (c), (d) to address the characterization of solid waste;
• 40 CFR 264.1(j)(2) to address the characterization of remediation waste;

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• 40 CFR 268.7(a), 9(a) to address the determination for management of hazardous waste;
• 40 CFR 268.34(f), 49(b), (c)(1) to address land disposal restrictions; and
• 10 CFR 61.55 to address low-level waste classification and characterization.
6.2.2 Location-Specific
Location-specific requirements set restrictions on the types of remedial activities that can be performed based on specific site characteristics or location. Location-specific standards provide a basis for assessing restrictions during the formulation and evaluation of site-specific remedies. Remedial actions may be restricted or precluded based on citing laws for hazardous waste facilities and based on proximity to wetlands, floodplains, or man-made features such as landfills, disposal areas, and/or local historic buildings.
The potential location-specific ARARs identified for remedial action at the site include:
• Archaeological and Historic Preservation Act (16 USC 469; PL 93-291; 88 Stat. 174);
• Migratory Birds Act (16 USC 703); and
• Bald and Golden Eagle Protection Act (16 USC 668-668d).
Archaeological and historical resources, as well as biological activities such as nesting and breeding, are not anticipated within Area 2 of SWMU 11 due to the area having been previously disturbed. However,
no surveys have been performed to rule out the presence of cultural or biological resources. If evidence of either is found during remedial work on site, work will immediately be stopped, and a cultural or biological resources specialist will be consulted. Additionally, biological activity is seasonal, so the
ARAR may be season-dependent and based upon the field schedule. All remedial actions performed at TR-5 and TR-6 must consider these restrictions and meet all necessary requirements.
6.2.3 Action-Specific
Action-specific requirements set controls or restrictions on the design, implementation, and performance of actions. These standards specify performance levels, actions, or technologies and specific levels for discharge of residual chemicals. They also provide a basis for assessing the feasibility and effectiveness
of the remedial alternatives.
The potential action-specific standards identified for remedial action at the site include the transportation of hazardous waste to a disposal facility (State Law, Title 19, Chapter 6, Solid and Hazardous Waste Act). All soil and debris must be transported from the site in accordance with this state law and meet all federal requirements.
Additional action-specific ARARs may include:
• 10 CFR 20.2006 and Appendix G to 10 CFR Part 20 to address the transfer for disposal and manifest of low-level radioactive waste by the generator;
• 40 CFR 262.11(a), (b), (c), (d) to address the characterization of solid waste;
• 40 CFR 262.254, 40 CFR 262.261, and 40 CFR 262.264 to address temporary on-site storage of hazardous waste and emergency procedures;

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• 40 CFR 264.1(j)(2) to address characterization of remediation wastes;
• 40 CFR 264.554 (d)(1), (h), (j)(1), (k) to address operation of staging piles;
• 40 CFR 268.7(a), 9(a) to address the determination for management of hazardous waste; and
• 40 CFR 268.34(f), 49(b), (c)(1) to address land disposal restrictions.
6.3 Development of Derived Concentration Guideline Levels as
Remedial Goals
As described in Section 4, site-specific DCGLs were developed for soil in TR-5 and TR-6. The Characterization Report (Appendix A) identified radiological COCs in soil and debris as a potential risk to human receptors, primarily site industrial workers. No risks to site workers were identified in groundwater. The remedial alternatives established for this site address the anticipated land use, RAOs, ARARs, and DCGLs as remedial goals for the site.
6.3.1 Chemical-Specific ARAR Applicability
The ARARs listed below are presented in relation to their applicability to DCGLs for site soil and debris. The COCs at Area 2 of SWMU-11 are radiological COCs.
Radiological Criteria for Unrestricted Use
ARARs for radiological COCs in soil at the site are identified in Radiological Criteria for Unrestricted
Use (Residential) (10 CFR 20.1402). Provisions of 10 CFR 20.1402 require that the annual dose to an average member of the critical group (i.e., residential receptor) not exceed 25 mrem/yr, and that the residual radioactivity be reduced to levels that are as low as reasonably achievable (ALARA). The soil
DCGLs for the residential receptor provided in Table 4 are based on 25 mrem/yr. DCGLs are based on a dose standard (i.e., 10 CFR 20.1402 and 1403) and are used as cleanup criteria (i.e., allowable soil concentrations) for the site. Full development of the DCGLs can be found in the Characterization Report
(Appendix A). Soil DCGLs for residential (unrestricted) use are most applicable to the remedial alternative of excavation.
Criteria for License Termination Under Restricted Conditions
ARARs for radiological COCs in soil at the site are identified in Criteria for License Termination Under Restricted Conditions (Industrial) (10 CFR 20.1403). Provisions of 10 CFR 20.1403 require that the annual dose to an average member of the critical group (i.e., industrial worker receptor) not exceed 25 mrem/yr, and that the residual radioactivity be reduced to levels that are ALARA. However, 10 CFR 20.1403 allows this dose limit to be achieved through the use of engineering and LUCs, with the added requirement that the annual dose does not exceed 100 mrem/yr should those institutional controls fail or if they are no longer in effect. The soil DCGLs for the industrial receptor provided in Table 5 are based on 100 mrem/yr. DCGLs are based on a dose standard (i.e., 10 CFR 20.1402 and 1403) and are used as
cleanup criteria (i.e., allowable soil concentrations) for the site. Full development of the DCGLs can be found in the Characterization Report (Appendix A). Soil DCGLs for industrial (restricted) use are most applicable to the remedial alternative of LUCs and capping.

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IDENTIFICATION AND SCREENING OF REMEDIAL TECHNOLOGIES
7.1 General Response Actions
This section presents the identification and screening of potentially applicable remedial technologies for attaining the RAOs at DPG. General Response Actions (GRAs) are broad categories of remedial actions intended to satisfy the RAOs. Appropriate GRAs are developed based on the RAOs, site-specific conditions, and contaminant characteristics. They may be implemented alone or in combination to achieve cleanup criteria (i.e., DCGLs). The EPA’s Guidance for Conducting Remedial Investigations and
Feasibility Studies under CERCLA (EPA, 1988) was the primary resource document used to select GRAs.
The following GRAs, as listed in column 1 of Table 6, have been identified to address radiological soil and debris contamination at DPG:
• No Action,
• LUCs,
• Containment,
• Excavation and Disposal, and
• Treatment.
7.2 Identification and Screening of Remedial Technologies and Process Options
This section describes the screening and evaluation of remedial technologies and process options, which
are conducted as follows:
• Identification of remedial technologies and process options;
• Screening criteria of remedial technologies and process options;
• Evaluation of remedial technologies and process options based on effectiveness, implementability, and cost; and
• Selection of remedial technologies and process options.
7.2.1 Identification of Technologies
Remedial technologies are the general categories of technologies by which a GRA is undertaken. Process options are the specific processes within a remedial technology by which the technology may be
implemented. Potential remedial technologies and process options are presented in columns 2 and 3 of Table 6.
7.2.2 Screening Criteria
Potential remedial technologies and process options are identified and evaluated based on technical feasibility. The retained process options are screened based on effectiveness, implementability, and cost to determine which process options should be used in the development of the remedial alternatives.

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Effectiveness
The effectiveness criterion addresses the ability of a technology to meet the RAOs, including overall protection of human health and the environment; compliance with regulations; long-term effectiveness and permanence; short-term effectiveness; and reduction of toxicity, mobility, or volume by treatment. The protection of human health and the environment considers the reduction, control, or elimination of risks at the site through the use of treatment, engineering, or LUCs. Compliance with regulations considers the ability of a technology to meet regulatory requirements. Long-term effectiveness and permanence include the consideration of the magnitude of risk associated with residuals or untreated waste at the site and the adequacy and reliability of post-closure activities required to maintain the integrity of the response action. Short-term effectiveness includes the consideration of community protection from air quality impacts, fugitive dust, transportation of hazardous materials, worker protection during implementation, environmental impacts, and the timeframe required to achieve protection. Reduction of toxicity, mobility, or volume includes the consideration of EPA’s policy of preference for
treatment and the extent and irreversibility of treatment.
Implementability
The implementability criterion addresses the technical and administrative feasibility of implementing a
technology and the availability of the materials and services required for implementation. In addition, the acceptance of a technology by regulatory agencies and the community is an important component in considering the implementability of any technology. Technical feasibility includes the consideration of
the reliability, maturity, prior application, and operational difficulties, as well as logistical, climate, and terrain limitations. Administrative feasibility includes the consideration of coordinating activities with regulatory agencies and obtaining permits, easements, right-of-way agreements, and zoning variances. The availability of materials and services includes considering the availability and distance to offsite treatment, storage, and disposal facilities, and required utility connections.
Cost
The cost criterion addresses the relative magnitude of capital and operation and maintenance (O&M) costs. Capital costs consist of direct and indirect costs. Direct costs include costs associated with
construction, equipment, materials, transportation, disposal, analytical services, treatment, and operation. Indirect costs include expenses related to engineering, design, legal fees, permits, and start-up. O&M costs include costs associated with operation, maintenance, energy, residual disposal, monitoring, and
support.
7.2.3 Evaluation of GRAs, Remedial Technologies, and Process Options
Table 6 lists the GRAs that were evaluated based on effectiveness, implementability, and relative costs.
GRAs and remedial technologies retained for further consideration and development of process options
are identified. Those GRAs that do not meet the criteria for effectiveness and implementability, or that are prohibitively expensive, are eliminated from further consideration.
No Action
The No Action GRA is evaluated and retained to establish a baseline for the comparison of the GRAs and subsequent remedial technologies. No response action of any kind would be employed at the site under
this category. Inclusion of No Action is required per 40 CFR Section 300.430(e)(6) and the NCP. No Action, by definition, involves no remedial action at the site and, therefore, has no technological barriers and no associated costs. The No Action GRA is not effective, as the potential risks to human health and
the environment would not be mitigated nor does it reduce the toxicity, mobility, or volume of contamination through treatment.

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LUCs
LUCs are a GRA consisting of institutional controls (ICs) and engineering controls used as remedial technologies to regulate activities at the site. ICs and engineering controls serve to reduce the potential for exposure to contamination; however, they do not reduce the environmental impacts. Radiological contamination present in the trenches is not physically altered nor is the mobility, toxicity, or volume of
soils and debris reduced.
The use of LUCs shall not be a substitute for active response measures (e.g., treatment and/or containment of source material) as the sole remedy unless such active measures are determined not to be practicable, based on the balancing of trade-offs among alternatives that is conducted during the selection of the remedy (40 CFR 300.430 (a)(iii)(D)). The objective for implementing LUCs at a site following remedy implementation is to protect remedies that are in place so that protection of human health and the environment is maintained. Additionally, LUCs serve to restrict land use until site conditions allow for unrestricted use and unlimited exposure. The EPA requires LUCs when site contaminant levels do not
allow for unrestricted use and unlimited exposure.
There are significant differences in the way LUCs are applied at federal facilities as compared to other sites. Some proprietary or governmental controls cannot be applied on active federal facilities. However,
for properties being transferred as part of a base closure, the DoD has authority to restrict property by retaining a property interest (i.e., an easement intended to assure the protectiveness of the remedy). For active bases, LUCs are commonly addressed through remedy selection documents, base master plans, and
separate MoUs.
Based on the EPA’s fact sheet, Institutional Controls: A Site Manager’s Guide to Identifying, Evaluating, and Selecting Institutional Controls at Superfund and RCRA Corrective Action Cleanups (EPA, 2000),
there are four general categories, or process options, of ICs:
• Governmental controls;
• Proprietary controls;
• Enforcement tools with institutional control components; and
• Informational devices.
At DPG, proprietary controls are not retained for consideration, as DPG is a federal facility and private
property is not a current land use. Governmental controls, enforcement tools, and informational devices are collectively considered administrative controls, and are retained due to their applicability at DPG. These process options allow the facility to specify the site or land usage, limit certain activities, and do not involve third parties to establish and enforce. At an active military installation such as DPG, the Garrison Manager is the local authority for regulating and enforcing ICs and administrative controls. Administrative controls may include LUCs and restrictions, signage, and permits. Administrative controls may be addressed in the Base Master Plan and are considered easy to implement, cost-effective, and maintain relative effectiveness when considered in conjunction with other remedial technologies.
Engineering controls include the process option of fencing. This option will serve to reduce the potential for exposure to radiological soil and debris by physically limiting site access to Area 2 of SWMU-11; however, it does not reduce the environmental impact. Engineering controls are easily implementable and
are considered relatively cost-effective. Fencing requires labor, materials, and logistical planning. Fencing may be installed around each individual trench or around both trenches contained together. This engineering control is retained and considered in conjunction with other technologies.

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Containment
Containment of radiological COCs through the remedial technology of capping effectively minimizes
surface water infiltration, controls erosion and surface water runoff, limits the potential leaching of contaminants to groundwater, and prevents direct contact to or external exposure from contaminated soil and radiological debris by human and ecological receptors. A cap will also serve to limit and/or reduce the external dose pathway, in addition to limiting erosion or dust generation of radiation-impacted soils. The cap does not pose significant impacts to human health or the environment due to construction or during the operational period. Capping is easily implementable, though capping material would require routine maintenance and inspection by a work crew. This remedial technology can be implemented with moderate capital costs and is therefore retained in conjunction with other remedial technologies.
Capping with a clay liner or a geosynthetic clay liner (GCL) are two process options evaluated for addressing radiological soil contamination within the trenches. Though both options prevent direct contact between potential receptors and impacted soil and meet RAOs, geomembranes and GCLs are
often favored over traditional clay liners as they provide a higher degree of impermeability, are less susceptible to leaks, and may require less maintenance and repair over time. Though a traditional clay liner may present an up-front lower cost when compared to a GCL, a clay liner requires additional
maintenance and testing over time. Proper moisture content and compaction standards must be achieved and QA/QC testing, including standard field tests with a nuclear density gauge, in-situ hydraulic conductivity tests, and laboratory tests on representative samples are typically required. In a semi-arid to
arid environment, such as that at DPG, desiccation cracking is also a concern. By comparison, a GCL does not require the same level of installation effort, requires less maintenance, testing, and inspection over time, and is not subject to desiccation cracking.
Excavation and Disposal
Soil excavation of both trenches (TR-5 and TR-6) physically removes the contaminated soil and debris and disposes of radiologically impacted materials by transporting them to an approved off-site facility. Excavation is considered effective as the potential for direct exposure to or external exposure from contaminated soil and radiological debris is eliminated, as is the transport of radionuclides to surrounding soil and groundwater. Process options include confirmation soil sampling, a magnetometer survey or real-time radiation detector, and sorting and screening of radiologically impacted materials. Confirmation soil sampling would be performed following excavation to confirm removal of all radiological material.
Sorting and screening of the excavated material on-site would segregate the radiologically contaminated debris (i.e., metal tubes) from the soil. A magnetometer or real-time radiation detector such as a FIDLER or a GM probe would be used to verify removal of trench-related debris and confirm soil contamination below screening levels is achieved. This would eliminate or reduce the possibility of a remobilization or re-excavation effort.
Following excavation, two options for soil replacement in the trenches are considered. One option would
completely remove all soil and debris from the trenches and replace with clean backfill from a location on DPG. The other option would sort and screen all soil and debris, and return all non-radiologically impacted soil to the trench. Additional clean backfill would be added if necessary.
Generally, excavation and disposal are easy to implement and have been used at similar sites. Costs may be moderate to high and must comply with both Federal and State of Utah transportation regulations. Consideration is given to the distance required for transporting materials offsite, as well as the cost to deploy on-site sorting and screening equipment. Additional consideration is given to the location of clean backfill material and its proximity to SWMU-11. Disposal requirements are expected to be the same for materials from either trench.

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Treatment
Treatment of radiological COCs through the remedial technology of in-situ soil treatment uses the process
option of cementitious solidification and stabilization of soils to eliminate the potential for leaching and migration of radionuclides from the site. Soil stabilization through the use of cement grout such as Portland cement or acrylamide grout, would treat low-level radiological waste in-situ. Grout is injected under pressure across the target area (i.e., trenches). Once solidified, the mobility of radionuclides in soil has been reduced. Soil stabilization using grout injection has been used at numerous sites to treat radiological waste and has been shown to reduce water infiltration and reduce exposure rate. Operations should be generally easy to implement with moderate costs.
7.2.4 Selection of Remedial Technologies and Process Options
The evaluation of the GRAs, remedial technologies, and process options are presented in Table 6. The screening and evaluation resulted in retention of remedial technologies and process options to be carried forward in the feasibility study process. The retained process options are used in the development and
detailed screening of the remedial alternatives. The rejected process options were eliminated from further consideration.

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DEVELOPMENT OF REMEDIAL ALTERNATIVES
The primary purpose of this FS is to develop appropriate remedial alternatives to address site-related contaminants that have been determined to pose an unacceptable risk to human health and the
environment per 40 CFR 300.430(e)(9). The remedial alternatives have been developed from technologies retained in the screening process, as summarized in Section 7. This section includes descriptions of the alternatives that have been retained and developed for TR-5 and TR-6 in Area 2 of SWMU-11. Although
the site is not intended for residential use, remediation to unlimited use/unrestricted exposure (UU/UE) is the ideal remedial goal.
8.1 Development of Remedial Alternatives for Radiological Contaminants of Concern in Soil
The following remedial alternatives for radiological COCs in soil were developed for TR-5 and TR-6 in
Area 2 of SWMU-11 with respect to site usage:
• Alternative 1: No Action;
• Alternative 2: LUCs;
• Alternative 3: Capping;
• Alternative 4: Excavation, Disposal, and Backfilling;
• Alternative 5: Excavation, Sorting, Screening, and Disposal; and
• Alternative 6: Soil Stabilization.
8.1.1 Alternative 1: No Action
Alternative 1 is the No Action alternative, as required per 40 CFR 300.430(e)(6) and the NCP. Under Alternative 1, no corrective action would be implemented. This alternative would not control the radiological hazards or risks posed by the COCs in soil and debris at either TR-5 or TR-6. This alternative
would have no capital or O&M costs. Although the No Action alternative is not considered a viable remedial option, it will be evaluated to establish a baseline of comparison regarding future performance and risk for the remaining remedial alternatives.
8.1.2 Alternative 2: Land Use Controls
LUCs would be implemented to ensure protection of human health and the environment, and to ensure that land use is restricted until contaminant concentrations are at levels that allow UU/UE. The EPA requires LUCs when site levels do not achieve UU/UE. They also serve to notify current and future users about the environmental conditions of the property. Fencing and signage would be the primary LUCs employed at Area 2 of SWMU-11.
8.1.3 Alternative 3: Capping
A containment or capping technology is used for impacted trench soil. This barrier layer would eliminate
potential direct contact to or exposure from radiologically-impacted soil. The cap does not pose significant impacts to human health or the environment due to construction or during the operational

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period. Installation of this type of cover is a proven and effective method of providing an exposure barrier and erosion control. Currently, there are no structures or barriers at Area 2 of SWMU-11 that would
impede construction of the cap. Because a cap leaves radiologically-impacted material in place, contamination is not removed and must therefore be maintained through periodic inspections and maintenance. As a result, this option must include all the elements of Alternative 2 (LUCs).
The MicroShield computer model was used to evaluate the cap thickness requirements for the trenches at SWMU-11. Cap thickness was based upon the allowable dose of 25 mrem/yr for an industrial worker. Provisions of 10 CFR 20.1403 (Criteria for License Termination Under Restricted Conditions) requires that the annual dose to an average member of the critical group not exceed 25 mrem/yr, and that the residual radioactivity be reduced to levels that are as low as reasonably achievable (ALARA). However, unlike 10 CFR 20.1402, 10 CFR 20.1403 allows this dose limit to be achieved through the use of engineering and land use controls (LUCs), with the added requirement that the annual dose does not exceed 100 mrem/yr should those institutional controls fail or if they are no longer in effect. Since the cap
is considered an engineering control that would be in place, preventing access to the waste, the 25 mrem/yr limit is considered appropriate for this analysis. Utilizing the maximum radionuclide soil concentrations at TR-5, it was determined that a cap would be required for exposure durations greater
than 5.3 hours per year for an industrial worker. A cap thickness of 0.9144 meters (3 ft) would allow an industrial worker to be exposed for a duration of 11,210.8 hours per year. Calculations and a discussion to determine cap thickness can be found in Appendix C.
The need for a cap at TR-6 is more complex. The MicroShield computer model determined that no cap is required at TR-6 for exposure durations of 2,783 hours per year or less for an industrial worker. Current usage by a site industrial worker is estimated to be approximately 2 hours per day, 5 to 10 days per year. If site usage by an industrial worker was increased, this maximum number of hours (2,783 hours) would not be exceeded. Therefore, based on current contamination levels at TR-6, no cap is required to achieve an acceptable exposure duration for an industrial worker at TR-6. However, the sealed metal tubes at TR-6 remain a potential source of contamination should they leak. Per NCP guidance, the time factor is 1,000 years, and a potential structural decay and leak is possible in the given timeframe. Therefore, a cap is also proposed to address contamination at TR-6. This cap would meet the same design specifications and standards as that of TR-5.
As discussed in Section 7.2.3, both process options, a clay liner and a GCL cap, achieve the same
outcome at a similar cost. A GCL cap, however, will provide the greatest reliability. For this reason, a cap with a GCL is retained as a process option, while a cap with a traditional clay liner is eliminated from further consideration.
8.1.4 Alternative 4: Excavation, Disposal, and Backfilling
Excavation of soil in TR-5 and TR-6 involves the physical removal of soil and/or impacted debris (i.e., metal tubes) via standard excavation practices and technology. Soil and/or debris would be
transported and disposed off-site in accordance with federal and state regulations for transportation and waste disposal. Materials handling, temporary containment of soils post-excavation, confirmation soil sampling and surveying, health and safety regulations for workers inside the trenches, and the availability of clean fill dirt are all considerations. Backfilling with clean fill and topsoil, grading, and revegetation after excavation would be required.
Excavation would satisfy the RAO of preventing direct contact to or external exposure from contaminated soil and radiological debris that may pose an unacceptable risk to human health and the environment. It would also prevent further migration of the soil COCs to areas beyond the trenches, such as buffer zones surrounding the trenches, air, and groundwater.

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For the Characterization Report (Appendix A), excavation soil waste volumes were recalculated using the overall dimensions provided by Cabrera in the Final Report (2016). For TR-5, the approximate
dimensions of 46 ft long by 17 ft wide by 7 ft deep yielded a result of 203 CY instead of 194 CY. Using a bulk factor of 1.5, the waste volume was calculated as 305 CY for TR-5. For TR-6, the approximate dimensions of 40 ft long by 20 ft wide by 6 ft deep yielded a result of 178 CY instead of 165 CY. Using a bulk factor of 1.5, the waste volume was calculated as 267 CY for TR-6. The square footage of each trench was determined to be 782 ft2 for TR-5 and 800 ft2 at TR-6. Sloping sidewalls were not included in the current waste volume calculations but may be added in the Decision Document (DD) if this alternative is the selected remedy.
8.1.5 Alternative 5: Excavation, Sorting, Screening, and Disposal
Alternative 5, Excavation, Sorting, Screening, and Disposal of contaminated soil and debris, is similar to Alternative 4 but would apply only to the soil and debris determined to be radiologically-impacted above screening limits; material below the screening limits would be returned to the trench. Excavation of soil
and debris would be removed via standard excavation practices and technology. Sorting and screening technologies would be employed on-site to determine which soil and debris were radiologically-impacted above screening limits. Impacted material would be transported offsite in accordance with federal and state
regulations for transportation and waste disposal. All soil determined to be below screening limits would be returned to the trench. Materials handling, temporary containment of soils and debris post-excavation, confirmation soil sampling, and health and safety regulations for workers sorting and screening the soil
and debris are all considerations. Grading and revegetation after excavation would be required.
Known debris at TR-6 is metal tubes, while at TR-5, metallic remnants from drum material are present. At TR-6, radiological contamination is primarily found in debris (i.e., metal tubes) and the amount of material above the screening limit is expected to be less than in TR-5. Due to the high cost of mobilization and demobilization of the soil screening technology, Alternative 5 would be applied to both TR-5 and TR-6 for ease of implementation and consistency. This remedial alternative would satisfy the RAO of preventing direct contact to or external exposure from contaminated soil and radiological debris that may pose an unacceptable risk to human health and the environment. It would also prevent further migration of the soil COCs to areas beyond the trenches, such as buffer zones surrounding the trenches, air, and groundwater.
8.1.6 Alternative 6: Soil Stabilization
In-situ soil treatment using cementitious solidification and stabilization, or soil stabilization, is an effective technology to treat radiological COCs. Using high-pressure concrete grouting techniques, Portland cement or acrylamide grout is injected across the target area to stabilize soil and debris within
the trenches. Once the grout has solidified, migration of radionuclides is reduced. Soil stabilization would limit the potential direct contact to external exposure from radiologically-impacted soil and would reduce the potential for migration of soil COCs to areas beyond the trenches. Grouting operations do not pose significant impacts to human health or the environment due to construction or during the operational period. Emplacement of this type of in-situ treatment has proven effective to treat radiologically-impacted wastes, to provide erosion control, and reduce water infiltration.
The MicroShield computer model was used to evaluate the exposure rate reduction of in-situ grout for TR-5 and TR-6. Using the maximum radionuclide concentrations for each trench (Cabrera, 2016), a silty soil composition, a grout density of 2.35 g/cm3, and input parameters representative of each trench, a
reduction in exposure rate of 30% was determined, as presented in Appendix D.

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Currently, there are no structures or barriers at Area 2 of SWMU-11 that would impede in-situ soil stabilization. Because in-situ soil stabilization consolidates radiologically-impacted material in place,
contamination is not removed and must therefore be maintained through periodic inspections and maintenance. As a result, this option must include all the elements of Alternative 2 (LUCs).
Cement grout would be injected under pressure across the target area for a combined surface area of 1,782 ft2. The grout would be injected to a depth of 10 ft bgs with a radius of influence of 6 ft in diameter. Two options for grout include Portland cement and acrylamide. The Portland cement mix would be used with no additives (i.e., fly ash, cement kiln) though may include URRICHEM to increase viscosity. Acrylamide, a low-viscosity grout, would contain a composition of the following: water, acrylamide solution, potassium ferricyanide solution, triethanolamine solution, ammonium persulfate, and sodium bicarbonate (baking soda) (Long, J., Huff, D., and A. Naudts, 1997). A pilot test would be performed before injections, and real time monitoring would be performed during injections to ensure parameters such as correct porosity, density of soils, strength and viscosity of the grout, were achieved. Acrylamide
grout has been shown to have a durability of more than 200 years (Long, J., Huff, D., and A. Naudts, 1997).

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DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES
9.1 Evaluation Criteria
This section presents and applies evaluation criteria, as specified in 40 CFR 300.430(e)(9), to anticipated alternative performance in detailed comparative analyses of the remedial alternatives developed in the previous section. These analyses are performed to aid in the selection of a preferred remedial alternative that best satisfies the criteria identified in 40 CFR 300.430(e)(9) and the specific RAOs, ARARs, and remedial goals. Section 300.430(e)(9) of the NCP lists nine criteria against which each remedial
alternative must be assessed. The acceptability or performance of each alternative against the criteria is evaluated individually so that relative strengths and weaknesses may be identified.
The first two threshold criteria must be met by each alternative:
• Protection of human health and the environment, and
• Compliance with ARARs.
The next five primary balancing criteria provide the basis for analysis:
• Long-term effectiveness and permanence;
• Reduction of toxicity, mobility, volume, or mass through treatment;
• Short-term effectiveness;
• Implementability; and
• Cost.
State acceptance and community acceptance are modifying criteria that will be evaluated in the DD following state and public comments on the Proposed Plan (PP). These modifying criteria are not
addressed in this FS.
9.1.1 Threshold Criteria
Overall Protection of Human Health and the Environment
This criterion addresses whether the remedial alternative achieves protection of human health and the environment over time considering the specific characteristics of the site. Protection of human health and the environment is met if each exposure pathway identified as potentially resulting in adverse effects is eliminated or reduced to an acceptable level or controlled through treatment or engineering and LUCs. How each alternative achieves protection over time and whether the site risks are eliminated, reduced, or controlled are also analyzed.
Compliance with ARARs
This criterion addresses whether the remedial alternative complies with federal and state environmental statutes, regulations, and other requirements that pertain to the site.

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9.1.2 Balancing Criteria
Long-Term Effectiveness and Permanence
This criterion relates to long-term effectiveness of the alternative in maintaining protection of human health and the environment after response objectives have been met. The focus is on any residual risk remaining at the site after completion of the remedial action and the reliability of engineering and
institutional controls and monitoring to manage hazardous substances remaining at the site.
Reduction of Toxicity, Mobility, Volume, and Mass
This criterion relates to the extent to which the remedial alternatives permanently reduce the toxicity, mobility, and volume of contaminants present at the site. Factors for this criterion include the degree of permanence of the remedial action, the amount of hazardous materials disposed offsite or destroyed/removed, and the type and quantity of residuals remaining.
Short-Term Effectiveness
Short-term effectiveness addresses the effects of the alternative during construction and implementation
until the RAOs are met. This criterion considers the protection of the community and workers, including the air quality effects and hazards from excavation, transportation, and on-site treatment. In addition, the expected length of time for completion of the remedial action is considered.
Implementability
This criterion relates to the technical and administrative feasibility of the remedial alternative. The specific factors to be considered are the ability to construct, operate, and maintain the technology; the
ability to monitor the effectiveness of the remedy; and the ability to obtain approvals from other agencies.
Cost
The cost estimates presented in this FS are developed to achieve a -30 percent to +50 percent accuracy range. The estimates were based on a variety of information, including generic unit costs, conventional cost estimating guides, and prior experience. Remedial Action Cost Engineering and Requirements (RACER®) software, which is widely used within the DoD and other federal agencies, was used to develop the cost estimates in this FS. The estimates have been prepared for use in the alternative evaluation based on information available at the time of the estimate. The actual costs of the project would depend on true labor and material costs, actual site conditions, final project scope, the implementation schedule, competitive market conditions, and other variable factors. The expected accuracy range of -30 percent to +50 percent is estimated over 30 years. Total cost represents the rounded
present worth value considering a discount rate of 1.5 percent for 30 years, based on the Office of Management and Budget (OMB) Circular A-94, Guidelines and Discount Rates for Benefit-Cost Analysis of Federal Programs (OMB, 2018). Contingencies have been applied to each alternative to take into consideration assumptions and uncertainties associated with the current project scope and unforeseen circumstances. A 30 percent contingency allowance was used to reflect uncertainties unless otherwise noted. Costs are rounded to the nearest $1,000 per EPA guidance.

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9.1.3 Modifying Criteria
State Acceptance
This criterion evaluates the technical and administrative issues and concerns the State of Utah may have regarding each of the alternatives. This criterion will be addressed in the DD once comments on the FS and PP have been received.
Community Acceptance
This criterion evaluates the issues and concerns the public may have regarding each of the alternatives. As with State Acceptance, this criterion will be addressed in the DD once comments on the FS and PP have been received.
9.2 Individual Alternative Analysis
The six individual alternatives, including the No Action alternative, will be evaluated in accordance with the seven criteria specified in Sections 9.1.1 and 9.1.2.
9.2.1 Alternative 1 – No Action
Alternative 1 leaves the trenches in Area 2 of SWMU-11 in their present condition with no LUCs or remedial actions. Radiologically-impacted soils and debris would remain as they currently exist in TR-5 and TR-6. Because contaminated media would be left on the site, a review of the site conditions would be required every 5 years, as specified in the NCP.
Alternative 1 serves as the baseline against which the effectiveness of other alternatives is evaluated and is included per the NCP. Table 7 presents a summary of Alternative 1 evaluated against the seven criteria presented below.
Overall Protection of Human Health and the Environment
Alternative 1 provides no protection to human health and the environment nor does it monitor impacted media or document land uses to ensure protection of human health and the environment. The No Action
Alternative does not reduce or control potential radiological exposure to soil or debris. Impacted soil and debris would not be removed, reduced, or controlled through treatment, engineering, and/or LUCs.
Compliance with ARARs
ARARs are not met with the No Action alternative, as no remedy would be implemented.
Long-Term Effectiveness and Permanence
The No Action alternative does not provide any controls for addressing reduction of radiological COCs over time aside from natural radioactive decay, reduction of radiological exposure, or the long-term management of impacted media; therefore, the No Action alternative does not meet this criterion.
Reduction of Toxicity, Mobility, Volume, and Mass
The No Action alternative does not employ any treatment that would reduce the toxicity, mobility, volume, or mass of impacted material; therefore, the No Action alternative does not meet this criterion.

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Short-Term Effectiveness
The No Action alternative does not pose any additional risks to the community, site industrial workers, or the environment since there are no remedial activities associated with it; however, it does not mitigate any existing or potential future risks/hazards.
Implementability
Alternative 1 has no action to implement, in that no action would be taken.
Cost
There are no present worth costs and capital costs for the No Action alternative because no action would
be taken.
9.2.2 Alternative 2 – Land Use Controls
Alternative 2 includes institutional and engineering controls. Fencing and signage would be the primary LUCs employed at Area 2 of SWMU-11. The LUCs would be kept in place until UU/UE could be achieved. DPG encompasses Area 2 of SWMU-11, which is currently owned and operated by the DoD.
Thus, implementation of this remedy does not require the approval or participation of landowners or private individuals. Because DPG is an active military installation, the local authority for regulating and enforcing ICs is the Garrison Manager. Therefore, DPG installation personnel will incorporate
enforceable restrictions into the Base Master Plan, instructions, and orders used by the Garrison Manager to govern conduct, actions and activities on the installation.
Table 7 presents a summary of Alternative 2 evaluated against the seven criteria presented below.
Overall Protection of Human Health and the Environment
Alternative 2 provides a low level of protection to human health by reducing the potential for radiological exposure in soil and debris. However, radiologically-impacted materials would not be eliminated or reduced, and the impact on the environment remains the same. Fencing would serve to create a physical barrier around the trenches, thus reducing the potential for exposure to radiological soil and debris, and to prevent inadvertent access to the trenches. Signage would inform potential receptors of the restricted land
use and potential exposure to radiologically-impacted media.
Current receptors at Area 2 of SWMU-11 are identified as site industrial workers. Although DPG is a federal facility and site access is already restricted, the fencing and signage provide additional limitations to the trenches by the current receptors. Site industrial workers may not be aware of the current potential exposure hazards that exist at the trenches. Additionally, if a trespasser or other human receptor was
present, fencing and signage would serve to reduce the potential for exposure. Fencing requirements are a 3-strand wire, thus allowing predators into the area. This is not a concern because ecological receptors were determined to not be at risk of exposure, given the current pathways. Overall, Alternative 2 adds a
degree of protection to human health and environment.
Compliance with ARARs
Chemical-specific ARARs were identified as Radiological Criteria for Unrestricted Use (Residential)
(10 CFR 20.1402) and Criteria for License Termination Under Restricted Conditions (Industrial) (10 CFR 20.1403). LUCs would comply with the chemical-specific ARARs for Restricted (Industrial) (10 CFR 20.1403) use.

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Location-specific ARARs were identified as the Archaeological and Historic Preservation Act, the Migratory Birds Act, and the Bald and Golden Eagle Protection Act. Additional chemical- and action-
specific ARARs described in Section 6.2 may need to be taken into consideration. Planning will be required to comply with all chemical-, location-, and action-specific ARARs.
Long-Term Effectiveness and Permanence
Radiologically-impacted soil and debris would remain in the trenches and the risk of human receptor exposure through potentially complete pathways (i.e., direct radiation, inhalation of re-suspended dust, and direct ingestion of soil) would remain indefinitely. Alternative 2 does provide some level of long-term effectiveness and permanence through the use of LUCs. Posted signs should alert human receptors of the risks associated with potential radiological exposure, and fencing should offer some level of
protection by restricting access to the trenches. However, an on-site land manager would not be present to ensure that engineering controls are effective. Periodic maintenance would be required to maintain the integrity of fencing and signs around the trenches.
Reduction of Toxicity, Mobility, Volume, and Mass
Alternative 2 does not provide a reduction in toxicity, mobility, volume, or mass, and radiological COCs would remain in soil and debris.
Short-Term Effectiveness
Construction activities for installation of fencing and signage are estimated to take less than 1 week to complete. A truck used to transport fencing and signage materials should have no impact on site traffic
flow. Installation of fencing and signage should not require extensive planning due to the size of the site and trenches. Fencing and signs would be placed around the perimeter of the trenches at an adequate distance such that there would be no potential for construction workers to come in contact with impacted soils. Any short-term risks to workers would be limited through the implementation of an approved health and safety plan and additional monitoring support during construction field activities, if deemed necessary. Potential environmental impacts would be addressed in the planning documents for this alternative and are considered to be minimal.
Implementability
Alternative 2 is considered technically feasible, and services and materials should be readily available. If LUCs are selected as a remedial action, and prior to implementation, provisions for legally enforceable ICs will be fully defined in the Remedial Design and detailed in a Land Use Control Implementation Plan
(LUCIP), both of which would be prepared and submitted to the Army and NRC before LUCs could proceed. Additional documents would include a DD and PP.
Alternative 2 construction activities (i.e., fence and sign installation) would be easy to implement due to
the amount of construction materials required and the size of TR-5 and TR-6 (approximately 782 ft2 and 800 ft2, respectively). Due to the size of the trenches, fencing could be installed around both trenches as one area, or around the trenches individually. Fencing would need to be 3-strand wire, as a chain-link
fence would preclude predators from entering the site and allow burrowing animals to contact soil and debris within the trenches. Signs would be installed at access points and around the entire perimeter of Area 2 of SWMU-11. Installation is anticipated to take approximately 1 to 2 days, with a 2- to 3-person
crew, depending on any site-specific requirements.
Although the work area has limited access, all site industrial workers and materials necessary to implement the engineering controls should be readily available through the site contractor and identified prior to construction activities. Health and safety protocols would need to be identified prior to

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construction activities to ensure a safe working environment for the industrial workers. Periodic maintenance by site industrial workers would be required to maintain the integrity of fencing and signs
around the trenches.
Administratively, implementation of Alternative 2 would require documentation and planning meetings. Documentation would include a Remedial Design, a LUCIP, a DD, a PP, and a Site-Specific Final Report. ICs would be fully defined in the Remedial Design and a LUCIP would be prepared detailing ICs prior to beginning installation activities. A Site-Specific Final Report would be prepared to document the completed remedial action. All land associated with TR-5 and TR-6 is part of DPG and is currently owned and operated by the DoD. Thus, implementation of this remedy does not require the approval or participation of landowners or private individuals. At DPG, ICs would be regulated and enforced by the Garrison Manager, and LUCs would be addressed in the Base Master Plans and separate MoU.
Cost
The cost estimate for implementation of LUCs for a 30-year timeframe was evaluated using RACER®
software. This estimate includes a LUCIP and other associated documentation, implementation of site use controls, planning meetings, access control signage, annual site inspections, and fencing costs for 3-strand wire fence. The total estimated cost for Alternative 2 is $167,000.
Appendix E and Table 8 provide a comprehensive breakdown of these costs, including capital costs, annual O&M costs, periodic costs, and the total present values of the alternatives. Although the remedy is expected to be in place longer than 30 years (1,000 years per NCP guidance), cost estimates are provided
in this FS for a 30-year timeframe.
9.2.3 Alternative 3 - Capping
Under Alternative 3, capping would provide containment of radiologically-impacted soil within TR-5 and
TR-6 and would be implemented in conjunction with LUCs.
Table 7 presents a summary of Alternative 3 evaluated against the seven criteria presented below.
Overall Protection of Human Health and the Environment
Capping of TR-5 and TR-6 at Area 2 of SWMU-11 would achieve RAOs by providing a physical barrier capable of eliminating direct contact to or exposure by current and future receptors from radiologically-impacted soil. Capping would also reduce the potential for migration of soil COCs. However, radiologically-impacted materials would not be eliminated or reduced, and the impact on the environment remains the same. Alternative 3 would be implemented in conjunction with LUCs, which would serve to
further limit exposure to impacted material. The caps would be protective of human health and the environment.
Compliance with ARARs
Alternative 3 would comply with chemical-, location-, and action-specific ARARs for soil.
The MicroShield model was used to determine a protective cap thickness based on an allowable dose of 25 mrem/yr for the industrial worker (Appendix C). Therefore, Alternative 3, used in conjunction with
LUCs, would comply with chemical-specific ARARs.

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Location-specific ARARs (identified as the Archaeological and Historic Preservation Act, the Migratory Birds Act, and the Bald and Golden Eagle Protection Act) would require planning and compliance by
capping activities and LUCs. Additional chemical- and action-specific ARARs described in Section 6.2 may also need to be taken into consideration.
Long-Term Effectiveness and Permanence
Alternative 3 would achieve long-term effectiveness and permanence through implementation of a GCL cap at TR-5 and TR-6 combined with LUCs. GCL caps and LUCs (i.e., fencing, signage, and land use restrictions) would provide erosion control as well as an effective and reliable long-term exposure barrier
for industrial workers. The caps would require routine maintenance and inspection by a work crew.
Reduction of Toxicity, Mobility, Volume, and Mass
Alternative 3 would permanently reduce the mobility of radiological COCs in soil through erosion and surface water control. However, the toxicity, volume, and mass of radiological COCs in soil would not be reduced.
Short-Term Effectiveness
Implementation of a GCL cap for both trenches, combined with LUCs, would result in an immediate reduction in potential exposure to site industrial workers.
Implementability
Installation of GCL caps and LUCs is technically feasible, and services and materials for both should be readily available. A GCL cap is a common technology and can be designed to specification. Fencing and signage, described in Section 9.2.2, can be obtained by site industrial workers. Prior to installation and implementation, provisions for legally enforceable ICs will be fully defined in the Remedial Design and detailed in a LUCIP, both of which would be prepared and submitted to the Army and NRC before work
could proceed. Additional documents would include a DD and PP.
Alternative 3 construction activities would include the design and construction of two GCL caps. Each cap, a RCRA hazardous waste cap GCL, would provide a protective cover of a minimum of 3 ft and be constructed of 40-millimeter high-density polyethylene (HDPE) geomembrane. The total area would be designed to cover TR-5 and TR-6 individually, although it could be expanded to cover both trenches, if determined appropriate.
Construction material for LUCs (i.e., fencing and signage) at both trenches is available. Due to the size of the trenches, fencing could be installed around both trenches as one area, or around the trenches
individually. Although the work area has limited access, all site industrial workers and materials necessary to implement the GCL caps and LUCs should be identified prior to construction activities. Health and safety protocols would need to be identified prior to beginning construction activities to
ensure a safe working environment for the industrial workers during installation. To document the completed remedial action, a Site-Specific Final Report would be prepared. Periodic maintenance by site industrial workers would be required to maintain the integrity of the GCL caps. Cap maintenance does not
require radiation-specific training by industrial workers if they do not breach the HDPE layer.
Administratively, implementation of Alternative 3 would require documentation and planning meetings. Documentation would include a Remedial Design, a LUCIP, a DD, a PP, and a Site-Specific Final
Report. ICs would be fully defined in the Remedial Design and a LUCIP would be prepared detailing ICs prior to beginning installation activities. A Site-Specific Final Report would be prepared to document the

Final Feasibility Study 42 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
completed remedial action. All land associated with TR-5 and TR-6 is part of DGP and is currently owned and operated by the DoD. Thus, implementation of this remedy does not require the approval or
participation of landowners or private individuals. At DPG, ICs would be regulated and enforced by the Garrison Manager, and LUCs would be addressed in the Base Master Plans and separate MoU.
Cost
The cost estimate for implementation of a GCL cap at TR-5 and TR-6 and LUCs for a 30-year timeframe was evaluated using RACER® software. This estimate includes two RCRA Hazardous Waste Cap GCL built to specification, a LUCIP and other associated documentation, planning meetings, access control signage, annual site inspections, and engineering controls. The total estimated cost for Alternative 3 is $383,000.
Appendix E and Table 8 provide a comprehensive breakdown of these costs, including capital costs, annual O&M costs, periodic costs, and total present value of Alternatives 3. The costs associated with Alternative 2, LUCs, are incorporated into this estimate. Although the remedy is expected to be in place
longer than 30 years (1,000 years per NCP guidance), cost estimates are provided in this FS for a 30-year timeframe.
9.2.4 Alternative 4 – Excavation, Disposal, and Backfilling
Under this alternative, the physical removal of radiologically-impacted soils and debris, off-site disposal, and backfilling with clean fill and topsoil would be implemented. The following discussion and evaluation apply to both TR-5 and TR-6.
Table 7 presents a summary of Alternative 4 evaluated against the seven criteria presented below.
Overall Protection of Human Health and the Environment
Excavation of radiologically-impacted soil and debris in TR-5 and TR-6 would achieve RAOs by
preventing direct contact to or external exposure from contaminated soil and radiological debris that may pose an unacceptable risk to human health and the environment. It would also prevent further migration of the soil COCs to areas beyond the trenches, such as buffer zones surrounding the trenches, air, and groundwater. Alternative 4 would thereby protect against both current and future human exposure to soil and would be protective of human health and the environment.
Compliance with ARARs
Alternative 4 would comply with chemical-, location-, and action-specific ARARs for soil.
Chemical-specific ARARs were identified as Radiological Criteria for Unrestricted Use (Residential)
(10 CFR 20.1402) and Criteria for License Termination Under Restricted Conditions (Industrial) (10 CFR 20.1403). The soil DCGLs for the residential receptor (unrestricted) use are provided in Table 4. Excavation of soil and debris will achieve UU/UE and would therefore comply with chemical-specific
ARARs.
Location-specific ARARs were identified as the Archaeological and Historic Preservation Act, the Migratory Birds Act, and the Bald and Golden Eagle Protection Act. Action-specific ARARs were
identified as those that address the transfer for disposal and manifest of low-level radioactive waste, temporary on-site storage of waste, staging piles, and land disposal restrictions. These ARARs would be required during the loading, marking, and manifesting of impacted soils and debris. Additional chemical- and action-specific ARARs described in Section 6.2 may need to be taken into consideration. Planning will be required to comply with all chemical-, location-, and action-specific ARARs.

Final Feasibility Study 43 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Long-Term Effectiveness and Permanence
Alternative 4 would achieve long-term effectiveness and permanence through the physical removal of
radiologically-impacted soil and debris from TR-5 and TR-6.
Reduction of Toxicity, Mobility, Volume, and Mass
Alternative 4 would permanently reduce the toxicity, mobility, volume, and mass of radiological COCs
via the physical removal of impacted soil and debris.
Short-Term Effectiveness
Implementation of Alternative 4 would be immediately effective upon excavation of impacted soil and debris; however, removal activities may result in minimal exposure risks to the construction/industrial workers via the release of fugitive dusts and runoff from disturbed soil. Dust controls may include water sprays or application of chemical dust suppressants. Surface water controls may also be required.
Implementability
Alternative 4 is technically implementable via standard excavation practices and technology. Excavation
can easily be performed, and typical equipment used may include backhoes, drag lines, clamshells, and vacuum trucks. Excavator services are readily available, as are the services and materials necessary for the transportation of excavated soil and debris to an approved off-site disposal facility or landfill.
Materials handling must be considered in the implementation of excavation. Staging areas would be used to prepare impacted soil and debris for disposal and transport; this area would be graded to reduce the potential for ponding and collapse of trench walls, lined to prevent groundwater contamination, and
bermed to prevent runoff. The off-site transportation of wastes resulting from excavation must meet Federal and State of Utah shipping and manifesting regulations. Excavated soil and debris would be transported to an approved landfill for disposal. The excavated area would be backfilled with clean soil, and a local fill dirt location may be available. Backfilling, grading, and revegetation after excavation are necessary to prevent stormwater runoff and erosion.
To ensure excavation was completed to meet unrestricted (residential) standards, or UU/UE, confirmation soil sampling and a magnetometer survey or use of a FIDLER or GM probe would be performed following excavation to ensure all radiologically-impacted materials had been removed. The extent of each trench has previously been evaluated and the general dimensions and extent of contamination within each individual trench are known.
While excavation and disposal of impacted soil and debris eliminates the environmental and health
concerns associated with direct contact of radiologically-impacted soil and debris, consideration must be given to the health and safety of site industrial/remedial workers. On-site air monitoring and dust and vapor control provisions would be necessary during excavation operations. Excavation activities can result in the release of fugitive dusts and runoff from disturbed soil. Dust controls could include water sprays or application of chemical dust suppressants. Surface water controls may also be required. Excavation at Area 2 of SWMU-11 would create minimal disturbance of the overall operational activities
of the surrounding facilities.

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Cost
The cost estimate for implementation of excavation, disposal, and backfilling was evaluated using
RACER® software. This estimate includes the total excavation of both trenches, temporary containment for storage of excavated materials, confirmation soil sampling, backfilling, trench restoration, and transportation to a local facility. The total estimated cost for Alternative 4 is $593,000.
Appendix E and Table 8 provide a comprehensive breakdown of these costs, including capital costs and total present values of the alternatives.
9.2.5 Alternative 5 – Excavation, Sorting, Screening, and Disposal
Alternative 5 involves the physical removal of soil and debris from both trenches, sorting and screening of radiologically-impacted material from non-radiologically impacted material, off-site disposal of impacted material, and backfilling with non-impacted soils. The primary difference between Alternative 5 and Alternative 4 is that Alternative 5 would incorporate a sorting and screening phase to process impacted soil and debris on-site.
Table 7 presents a summary of Alternative 5 evaluated against the seven criteria presented below.
Overall Protection of Human Health and the Environment
Excavation of radiologically-impacted soil and debris would achieve RAOs by preventing direct contact
to or external exposure from contaminated soil and radiological debris that may pose an unacceptable risk to human health and the environment. It would also prevent further migration of the soil COCs to areas beyond the trenches, such as buffer zones surrounding the trenches, air, and groundwater. Alternative 5
would thereby protect against both current and future human exposure to soil and would be protective of human health and the environment.
Compliance with ARARs
Alternative 5 would comply with chemical-, location-, and action-specific ARARs for soil.
Chemical-specific ARARs were identified as Radiological Criteria for Unrestricted Use (Residential) (10 CFR 20.1402) and Criteria for License Termination Under Restricted Conditions (Industrial) (10 CFR 20.1403). The soil DCGLs for the residential receptor (unrestricted) use are provided in Table 4. Excavation of impacted soil and debris from the trenches will achieve UU/UE and would therefore comply with chemical-specific ARARs.
Location-specific ARARs were identified as the Archaeological and Historic Preservation Act, the Migratory Birds Act, and the Bald and Golden Eagle Protection Act. Action-specific ARARs were
identified as those that address the transfer for disposal and manifest of low-level radioactive waste, temporary on-site storage of waste, staging piles, and land disposal restrictions. These ARARs would be required during the loading, marking, and manifesting of impacted soils and debris. Additional chemical-
and action-specific ARARs described in Section 6.2 may need to be taken into consideration. Planning will be required to comply with all chemical-, location-, and action-specific ARARs.
Long-Term Effectiveness and Permanence
Alternative 5 would achieve long-term effectiveness and permanence through the physical removal of radiologically-impacted soil and debris from the trenches.

Final Feasibility Study 45 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Reduction of Toxicity, Mobility, Volume, and Mass
Alternative 5 would permanently reduce the toxicity, mobility, volume, and mass of radiological COCs
via the physical removal of impacted soil and debris from the trench.
Short-Term Effectiveness
Implementation of Alternative 5 would be immediately effective upon excavation of impacted soil and debris; however, removal activities may result in minimal exposure risks to the construction/industrial workers via the release of fugitive dusts and runoff from disturbed soil. Dust controls may include water sprays or application of chemical dust suppressants. Surface water controls may also be required.
Implementability
Alternative 5 is technically implementable via standard excavation practices and technology. Excavation can easily be performed, and typical equipment used may include a backhoe and vacuum truck. Excavator services are readily available, as are the services and materials necessary for the transportation of excavated soil and debris to an approved off-site disposal facility or landfill. However, the technology
used for sorting and screening of soils and debris may be less feasible.
As with Alternative 4, materials handling must be considered. Staging areas would be used to prepare impacted soil and debris for on-site radiological screening and processing, disposal, and transport. The
staging area would be graded to reduce ponding and collapse of trench walls, lined to prevent groundwater contamination, and bermed to prevent runoff. The off-site transportation of wastes resulting from excavation must meet Federal and State of Utah shipping and manifesting regulations. Excavated
soil and debris would be transported to an approved disposal facility. The excavated area would be backfilled with non-impacted soil and clean backfill, if required, and non-impacted material would be returned to the trench. Backfilling, grading, and revegetation after excavation are necessary to prevent
stormwater runoff and erosion.
To ensure excavation was completed to meet unrestricted (residential) standards, or UU/UE, confirmation soil sampling and a magnetometer survey or use of a FIDLER or GM probe would be performed following excavation to ensure all radiologically-impacted materials above the screening limits had been removed. The extent of each trench has previously been evaluated and the general dimensions and extent of contamination within each individual trench are known.
While excavation and disposal of impacted soil and debris eliminate the environmental and health concerns associated with direct contact of radiologically-impacted soil and debris, consideration must be
given to the health and safety of site industrial/remedial workers. On-site air monitoring and dust and vapor control provisions would be necessary during excavation operations. Excavation activities can result in the release of fugitive dusts and runoff from disturbed soil. Dust controls could include water
sprays or application of chemical dust suppressants. Surface water controls may also be required. Excavation at Area 2 of SWMU-11 would create minimal disturbance of the overall operational activities of the surrounding facilities.
The technology used to sort and screen impacted soils and debris will be transported from an off-site location and will incur a high mobilization/demobilization cost (Section 9.2.5). On-site radiological screening involves the pre-treatment of soils and debris by screening and tilling, followed by the processing of all materials. Implementing sorting and screening of soils to separate radiologically-impacted materials from non-radiologically impacted materials may not be feasible given that the same outcome (unrestricted residential use) is achieved with Alternative 4 at a lower cost. Development of this comparison is made in Section 9.3.6.

Final Feasibility Study 46 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Cost
The cost estimate for implementation of excavation, sorting, screening, and disposal was evaluated using
RACER® software. This estimate includes the mobilization and demobilization of soil screening technology, total excavation of both trenches, temporary containment for storage of excavated materials, confirmation soil sampling, backfilling, trench restoration, on-site radiological screening and processing,
and transportation to a local facility. The total estimated cost for Alternative 5 is $1,439,000.
Appendix E and Table 8 provide a comprehensive breakdown of these costs, including capital costs and total present values of the alternatives.
9.2.6 Alternative 6 – Soil Stabilization
Under Alternative 6, in-situ soil stabilization using cement or acrylamide grouting techniques would
provide containment of radiologically-impacted soil and debris within TR-5 and TR-6 and would be implemented in conjunction with LUCs.
Table 7 presents a summary of Alternative 6 evaluated against the seven criteria presented below.
Overall Protection of Human Health and the Environment
Soil stabilization through the injection of cement or acrylamide grout at TR-5 and TR-6 would achieve RAOs by limiting direct contact to or exposure by current and future receptors from radiologically-
impacted soil. Soil stabilization would also reduce the potential for migration of soil COCs. However, radiologically-impacted materials would not be eliminated or reduced. Alternative 6 would be implemented in conjunction with LUCs, which would serve to further limit exposure to impacted material. Soil stabilization would protect against both current and future human exposure to soil and would be protective of human health and the environment.
Compliance with ARARs
Alternative 6 would comply with chemical-, location-, and action-specific ARARs for soil.
Chemical-specific ARARs were identified as Radiological Criteria for Unrestricted Use (Residential) (10 CFR 20.1402) and Criteria for License Termination Under Restricted Conditions (Industrial) (10 CFR 20.1403). In-situ stabilization of soil and debris would be used in conjunction with LUCs (Alternative 2) to comply with the chemical-specific ARARs for Restricted (Industrial) (10 CFR 20.1403) use.
Location-specific ARARs were identified as the Archaeological and Historic Preservation Act, the Migratory Birds Act, and the Bald and Golden Eagle Protection Act. Additional chemical- and action-specific ARARs described in Section 6.2 may need to be taken into consideration. Planning will be
required to comply with all chemical-, location-, and action-specific ARARs.
Long-Term Effectiveness and Permanence
Alternative 6 would achieve long-term effectiveness and permanence through cement or acrylamide
grouting of soil and debris at TR-5 and TR-6. Acrylamide grout has shown to have durability of more than 200 years. LUCs (i.e., fencing, signage, and land use restrictions) would provide erosion control as well as an effective and reliable long-term exposure barrier for industrial workers. The stabilized material
would require routine maintenance and inspection by a work crew.

Final Feasibility Study 47 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Reduction of Toxicity, Mobility, Volume, and Mass
Alternative 6 would permanently reduce the mobility of radiological COCs in soil through erosion and surface water control, and by reducing water infiltration. However, the toxicity, volume, and mass of radiological COCs in soil would not be reduced.
Short-Term Effectiveness
Implementation of soil stabilization through cement or acrylamide grouting for both trenches, combined with LUCs, would result in an immediate reduction in potential exposure to site industrial workers. However, injection activities may result in minimal exposure risks to the industrial workers via the release of fugitive dusts and runoff from disturbed soil. Dust controls may include water sprays or application of chemical dust suppressants. Surface water controls may also be required.
Implementability
Injection of grout for soil stabilization is technically feasible, and services and materials should be generally available. In-situ soil stabilization is a commonly used technique for the treatment of hazardous waste and low-level radioactive waste. Cementitious materials are the predominant materials of choice because of their low associated processing costs and are considered environmentally friendly. Fencing and signage, described in Section 9.2.2, can be obtained by site industrial workers. Prior to installation
and implementation, a LUCIP would be prepared and submitted to the Army and NRC before work could proceed. Additional documents would include a DD and PP.
Alternative 6 injection activities would include high pressure injection of Portland cement or acrylamide
grout into TR-5 and TR-6 to a depth of approximately 10 ft bgs covering an approximate are of 1,782 ft2. The radius of influence would be 6 ft in diameter. Prior to grouting, a trial grouting or pilot test may be conducted on a small-scale to confirm that the design objectives could be met and to make the necessary adjustment to grouting procedures, equipment, grout mix, injection pressures, injection sequence, and waste management. Grouting operations would be monitored and assessed in real time using geotechnical testing to ensure proper construction, porosity, density of soils, strength and viscosity of the grout.
Construction material for in-situ soil stabilization would include equipment which would install grouting rods and perform high-pressure injections, and equipment for mixing, spreading, and compacting. Post-installation, the stabilized mass may be subject to compressive strength and durability testing. Stabilized grout would need to pass freeze/thaw and wet/dry testing. The recommended NRC test requires testing without controlling humidity, allowing drying of the grout at the highest temperature.
Construction material for LUCs (i.e., fencing and signage) at both trenches is available. Due to the size of the trenches, fencing could be installed around both trenches as one area, or around the trenches individually. Although the work area has limited access, all site industrial workers and materials
necessary to implement soil stabilization and LUCs should be identified prior to construction activities. Health and safety protocols would need to be identified prior to beginning construction activities to ensure a safe working environment for the industrial workers during installation.
While injection of impacted soil and debris eliminates the environmental and health concerns associated with direct contact of radiologically-impacted soil and debris, consideration must be given to the health and safety of site industrial workers. On-site air monitoring and dust and vapor control provisions would be necessary during injection operations. Injection activities can result in the release of fugitive dusts and runoff from disturbed soil. Dust controls could include water sprays or application of chemical dust suppressants. Surface water controls may also be required. However, injection activities at Area 2 of SWMU-11 would create minimal disturbance of the overall operational activities of the surrounding facilities.

Final Feasibility Study 48 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
To document the completed remedial action, a Site-Specific Final Report would be prepared. Periodic maintenance by site industrial workers may be required to ensure the condition of the grout is maintained
(i.e., cracking), in addition to maintaining the integrity of fencing and signs around the trenches.
Administratively, implementation of Alternative 6 would require documentation and planning meetings. All land associated with TR-5 and TR-6 is currently owned and operated by the DoD. Thus, implementation of this remedy does not require the approval or participation of landowners or private individuals. For active bases, LUCs are commonly addressed through remedy selection documents, base master plans, and separate MoUs.
Cost
The cost estimate for grout injection at TR-5 and TR-6 and LUCs for a 30-year timeframe was evaluated using RACER® software. This estimate includes high-pressure injection of grout, a pilot test and geotechnical testing, a LUCIP and other associated documentation, planning meetings, access control signage, periodic site inspections, and engineering controls. The total estimated cost for Alternative 6 is
$487,000.
Appendix E and Table 8 provide a comprehensive breakdown of these costs, including capital costs, annual O&M costs, periodic costs, and total present value of Alternatives 6. The costs associated with
Alternative 2, LUCs, are incorporated into this estimate. Although the remedy is expected to be in place longer than 30 years (1,000 years per NCP guidance), cost estimates are provided in this FS for a 30-year timeframe.
9.3 Comparative Alternative Analysis
9.3.1 Overall Protection of Human Health and the Environment
The remedial technologies that provide the greatest overall protection of human health and the environment are Alternatives 4 and 5. Through removal of radiologically-impacted soil and debris from
the trenches, UU/UE is achieved immediately and has long-term effectiveness and permanence.
Alternatives 2, 3, and 6 do not achieve UU/UE and contamination is not eliminated or reduced. Alternative 1 does not provide additional protection of human health and the environment.
9.3.2 Compliance with Applicable or Relevant and Appropriate Requirements
The chemical-specific ARARs for Radiological Criteria for Unrestricted Use (Residential) (10 CFR 20.1402) are achieved through Alternatives 4 and 5. Location- and action-specific ARARs are also met with these two remedial alternatives. Alternatives 2, 3, and 6 do, however, comply with the ARAR Criteria for License Termination Under Restricted Conditions (Industrial) (10 CFR 20.1403).
9.3.3 Long-Term Effectiveness and Permanence
Alternatives 4 and 5 would achieve long-term effectiveness and permanence through the physical removal of radiologically-impacted soil and debris from TR-5 and TR-6.
While Alternatives 2, 3, and 6 do provide a level of long-term effectiveness and permanence through LUCs, GCL caps, and soil stabilization, respectively, radiologically-impacted soil and debris would remain in the trenches indefinitely. With Alternative 2, the risk of human receptor exposure through
potentially complete pathways (i.e., direct radiation, inhalation of re-suspended dust, and direct ingestion of soil) would also remain.

Final Feasibility Study 49 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
The No Action alternative does not meet this criterion.
9.3.4 Reduction of Toxicity, Mobility, Volume, and Mass
Alternatives 4 and 5 would permanently reduce the toxicity, mobility, volume, and mass of radiological COCs via the physical removal of impacted soil and debris.
Though Alternatives 3 and 6 would reduce the mobility of radiological COCs in soil, the toxicity, volume, and mass would not be reduced. Similarly, Alternative 2 does not provide a reduction in toxicity, mobility, volume, or mass nor is mobility of COCs impeded.
The No Action alternative does not meet this criterion.
9.3.5 Short-Term Effectiveness
Alternatives 3, 4, 5, and 6 would result in an immediate reduction in potential exposure to site industrial workers and the environment. The potential for exposure by site industrial workers to radiologically-impacted materials is possible during the implementation of all three alternatives. However, the exposure is expected to be less in Alternative 3 and 6 than the potential exposure of an industrial worker in
Alternatives 4 and 5.
Alternative 2 is effective upon installation of fencing and signage, though the effectiveness is substantially less than in Alternatives 3, 4, 5, and 6. Alternative 1 does not mitigate any existing or future
risks or hazards.
9.3.6 Implementability
Alternative 1 is the most easily implemented alternative as there are no required actions.
Compared to Alternatives 3, 4, 5, and 6, Alternative 2 is considered easily implementable and involves the fewest industrial workers, the shortest construction and implementation time, and the fewest materials. Administratively, it is the easiest to complete, as compared with the other remaining alternatives.
Alternatives 3, 4, 5, and 6 require a larger number of industrial workers, health and safety monitoring, and more materials to implement. For these three alternatives, services, personnel, and materials are generally readily available but require greater coordination and planning. Health and safety protocols would need to be identified prior to construction activities to ensure a safe working environment for the industrial workers during remedy implementation could begin. Alternatives 3 and 6 require periodic maintenance by site workers to maintain the integrity of the caps and grouted trenches.
Alternatives 4 and 5 require the highest level of implementation. Both require adherence to federal and state disposal and transportation regulations. Heavy equipment used for excavation and backfilling, as well as
staging areas and trench specification, would be used. Confirmation soil sampling and radiological scans would also be required. Backfilling, grading, and revegetation following excavation would be necessary.
Alternative 5 would require the use of additional technologies for soil and debris sorting and screening. These technologies would require transport from a greater distance and come at a higher cost. Mobilization and demobilization costs are considerable. On-site radiological screening involves the pre-treatment of soils and debris by screening and tilling, followed by processing all materials. This
would require additional time and labor. Of all alternatives, Alternative 5 is the least implementable.

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9.3.7 Cost
The total estimated costs for implementing the alternatives at TR-5 and TR-6 are included in Table 8. These costs were obtained from the Basis of Cost Estimates presented in Appendix E. Cost-specific breakdowns of line items are also provided in the Folder Assembly Level Data Report in Appendix E. The capital and O&M cost breakdown for each alternative, if applicable, is provided below:
• Alternative 1 (No Action) – No associated capital, O&M, or periodic costs.
• Alternative 2 (LUCs) – Capital costs include labor and materials for the installation of fencing and signage and implementation of LUCs by the DoD. Annual O&M costs include annual site inspections and multiple 5-year reviews. Periodic costs include site inspection and maintenance, administrative
documentation, planning, meetings, and five-year reviews.
• Alternative 3 (GCL Capping) – Capital costs include labor and materials for design, construction, and installation of the GCL caps. Capital costs also include labor and materials for the installation of fencing and signage and implementation of LUCs by the DoD. Annual O&M costs include annual site inspections. Periodic costs include site inspection and maintenance, administrative
documentation, planning, meetings, and five-year reviews.
• Alternative 4 (Excavation, Disposal, and Backfilling) – Capital costs include labor and materials to excavate the trenches, set up containment areas, perform confirmation soil sampling, backfill with clean fill dirt, transport impacted-materials off-site, and restore the surface with native vegetation. Costs also include administrative documentation, planning, and meetings.
• Alternative 5 (Excavation, Sorting, Screening, and Disposal) – Capital costs include the mobilization and demobilization of soil screening technology, labor and materials to excavate the trenches, set up containment areas, perform pre-treatment of the soils by screening, process all materials, perform confirmation soil sampling, backfill with clean fill dirt, transport impacted-materials off-site, and restore the surface with native vegetation. Costs also include administrative documentation, planning,
and meetings.
• Alternative 6 (Soil Stabilization) – Capital costs include labor and materials for high-pressure grouting of the trenches, and QC and geotechnical testing. Capital costs also include labor and materials for the installation of fencing and signage and implementation of LUCs by the DoD. O&M and periodic costs include site inspection and maintenance, administrative documentation, planning, meetings, and five-year reviews.

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SUMMARY AND CONCLUSION
The six remedial alternatives presented in this FS are developed, screened, and evaluated to address site-related contaminants determined to pose an unacceptable risk to human health and the environment. The
remedial alternatives are evaluated based on the nature and extent of contamination, the ability to satisfy RAOs and achieve remedial goals, and compliance with chemical-, location, and action-specific ARARs. Remedial technologies are identified and screened through evaluation criteria for an individual and
comparative analysis. The selected remedy alternative will be determined based upon the outcome of the PP.

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Final Feasibility Study 53 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
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Institutional Controls at Superfund and RCRA Corrective Action Cleanups. EPA/540/F-00/005. OSWER 9355.0-74FS-P. U.S. Environmental Protection Agency. September 2000.
Kamboj, S., E. Gnanapragasam, and C. Yu, 2018. User’s Guide to RESRAD-ONSITE Code, Version 7.2. ANL/EVS/TM-18/1, Environmental Science Division, Argonne National Laboratory, March 2018.
Long, J., Huff, D., and A. Naudts, “A Case Study – Using a Multi-Grout Barrier to Control “Sr Release at ORNL”, International Containment Technology Conference Proceedings, St. Petersburg, Florida, 1997, 571-577.

Final Feasibility Study 54 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Marsh, Geoffrey G., 2017. “Annual Operation Safety Survey (OSSA) for the SWMU-11 site to consider safety and radiological conditions.” Memorandum for Dugway Proving Ground Director
Installation Safety, RSO. October 24.
North Wind, 2019. Draft Final Characterization Report Area 2 of SWMU-11 Dugway Proving Ground, Dugway, Utah. October 2019.
NRC-DoD MoU, 2016. “Memorandum of Understanding Between the United States Nuclear Regulatory Commission and the United States Department of Defense for Coordination on CERCLA Response Actions at DOD Sites with Radioactive Materials,” Scott W. Moore, Acting Director Office of Nuclear Material Safety and Safeguards and Maureen Sullivan Deputy Assistant Secretary of Defense (Environment, Safety and Occupational Health).
OMB, 2018. Guidelines and Discount Rates for Benefit-Cost Analysis of Federal Programs, Circular A-94, Memorandum for Heads of Executive Departments and Establishments, Appendix C. Revised November.
Parsons, 2009. Final Phase II RCRA Facility Investigation: SWMU-11 Addendum, Dugway Proving
Ground, Dugway, Utah, Parsons Engineering Science, Salt Lake City, UT, August.

Final Feasibility Study 55 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
TABLES

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Final Feasibility Study 57 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Table 1. TR-5 and TR-6 2005 Phase II Investigation Results.
Gamma Exposure Rate Measurements
Trench Result (µR/hr) Center of Trench Result (µR/hr) 3 ft from Center Result (µR/hr) 6 ft from Center
TR-5 420 50 30
FIDLER and GM Pancake Probe - Gamma and Beta Measurements
Trench Result (cpm) Directly Over Area
Background Radiation Levels FIDLER Results (cpm) Background Radiation Levels GM Probe Results (cpm)
TR-5 1,200 - 575,000 25,000 - 28,000 75 - 125
Material Samples
Trench Notes Depth Result
TR-6 (MS02) Solidified sand from inside a corroded drum 6 ft bgs No detectable levels of radioactivity
TR-6 (MS03) Multiple buried metal tubes NA Sample not sent to laboratory, remains on site. Gamma radiation
signature similar to Cesium-137
TR-5 (MS04 &
MS04A)
Metal remnants of
drum material 0.5 ft bgs Radioactivity primarily due to Strontium-90 (results on following Table 1)
Notes: µR/hr - microroentgen per hour ft - feet FIDLER - Field Instrument for the Detection of Low Energy Radiation GM - Geiger Mueller cpm - counts per minute MS - Material Sample bgs - below ground surface NA - isotopic analysis not used with background samples

Final Feasibility Study 58 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020

Final Feasibility Study 59 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Table 2. TR-6 Maximum Radionuclide Soil Concentrations.
Radionuclide
Maximum Soil Concentration (pCi/g)
Cs-137 1.22
Nb-94 0.019
Ra-226 2.03
U-232 3.86
U-234 2.74
U-238 1.71
Table 3. TR-5 Maximum Radionuclide Soil and Debris Concentrations.
Radionuclide
Maximum Soil Concentration (pCi/g)
Maximum Debris Concentration (pCi/g)
Cs-137 1.6 --
Nb-94 8.9 --
Ra-226 3,040 --
Pu-242 -- 19.7
Po-210 -- 3,520
Th-229 -- 30.6
Th-230 -- 0.74
U-232 3.91 26.2
U-234 6.4 0.8
U-235 0.13 0.13
U-238 6.7 0.81
Table 4. Soil DCGLs for Unrestricted (Residential) Use.
Nuclide
TR-5 Dose-To-Source-Ratio (DSR) (mrem/yr per pCi/g)
TR-5 DCGL (25 mrem) (pCi/g)
TR-6 Dose-To-Source Ratio (DSR) (mrem/yr per pCi/g)
TR-6 DCGL (25 mrem) (pCi/g)
Carbon-14 1.43E-02 1,753 1.21E-02 2,070
Cesium-137 7.62E-01 33 7.55E-01 33
Niobium-94 2.07E+00 12 2.06E+00 12
Lead-210 9.25E-01 27 8.38E-01 30
Plutonium-242 1.07E-01 234 9.84E-02 254
Radium-226 3.39E+00 7.4 3.26E+00 7.7
Strontium-90 5.29E-01 47 4.80E-01 52
Thorium-229 5.71E-01 44 5.58E-01 45
Thorium-230 8.07E-01 31 7.74E-01 32
Thorium-232 4.04E+00 6.2 3.95E+00 6.3
Uranium-232 1.75E+00 14 1.73E+00 14
Uranium-234 1.98E-02 1,261 1.85E-02 1,353
Uranium-235 1.96E-01 128 1.94E-01 129
Uranium-238 5.12E-02 488 4.98E-02 502

Final Feasibility Study 60 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Table 5. Soil DCGLs for Restricted (Industrial) Use.
Nuclide
TR-5 Dose-To-Source-Ratio (DSR) (mrem/yr per pCi/g)
TR-5 DCGL (100 mrem) (pCi/g)
TR-6 Dose-To-Source-Ratio (DSR) (mrem/yr per pCi/g)
TR-6 DCGL (100 mrem) (pCi/g)
Carbon-14 1.50E-06 6.68E+07 1.40E-06 71,479,628
Cesium-137 5.82E-01 172 5.79E-01 173
Niobium-94 1.65E+00 61 1.64E+00 61
Lead-210 3.14E-02 3,188 2.86E-02 3,499
Plutonium-242 2.33E-02 4,284 2.19E-02 4,564
Radium-226 1.83E+00 55 1.82E+00 55
Strontium-90 5.02E-03 19,916 4.94E-03 20,239
Thorium-229 3.50E-01 285 3.47E-01 288
Thorium-230 5.00E-01 200 4.97E-01 201
Thorium-232 2.62E+00 38 2.60E+00 38
Uranium-232 1.39E+00 72 1.38E+00 73
Uranium-234 4.25E-03 23,552 4.10E-03 24,414
Uranium-235 1.46E-01 687 1.45E-01 691
Uranium-238 3.00E-02 3,329 2.98E-02 3,358

Final Feasibility Study 61 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Table 6. Evaluation of General Response Actions, Remedial Technologies, and Process Options.
General Response Action Remedial Technology Process Option Effectiveness Evaluation Implementability Evaluation Relative Cost Evaluation Retained? Considerations
No Action None None Not effective. The No Action alternative does not
address risk/hazard or reduce the toxicity, mobility, or volume of contamination through treatment. However, it is retained for consideration in the alternatives assembly to measure the effectiveness of the other alternatives.
Not Applicable - No Implementation No Cost Yes. Required by NCP and
USEPA guidance as a baseline for comparison to other options.

Land Use Controls Institutional Controls Governmental Controls Effective as they do not require negotiation, drafting, or recording of parcel-by-parcel proprietary controls.
Governmental controls remain effective if they are not repealed and are enforced. Examples include zoning; building codes; groundwater use regulations; commercial fishing bans or limits. DOD possesses the
authority to enforce ICs on their property.
DPG can specify site uses. Negligible cost. Yes. Considered in conjunction with other
technologies.

Proprietary Controls Effective when restrictions on activities are intended to be long-term or permanent between a property owner
and second party. Requires the transfer of property to be enforceable. Examples include restricted-use
easements and restrictive covenants which can prohibit activities that may compromise the effectiveness of a
response action, restrict activities or future resource use, thereby resulting in unacceptable risk to human
health or the environment.
Can be implemented without the intervention of any federal, state,
or local regulatory authority.
Moderate capital and O&M costs to implement and
maintain.
No. Government facility.

Enforcement Tools with Institutional
Control Components
Effective but typically only binding on the original signatories of the agreement. Enforceable by USEPA
under CERCLA and RCRA or by a state. Examples include legal tools such as administrative orders,
permits, Federal Facility Agreements which limit certain site activities.
Easier to establish than proprietary controls because USEPA is not
dependent on third parties to establish and enforce.
Negligible cost. Yes: Considered in conjunction with other
technologies.

Information Devices Effective as reduces potential for exposure but does not
reduce environmental impacts. Examples include signage, state registries of contaminated sites, tracking systems, and consumption advisories.
DPG can specify site uses. Negligible cost. Yes: Considered in
conjunction with other technologies.
Engineering Controls Fencing Reduces potential for exposure but does not reduce environmental impacts. High: Requires labor and materials, logistics planning. Low to Moderate capital and O&M costs to implement and
maintain. Maintenance requires recurring inspection and repairs.
Yes: Considered in conjunction with other
technologies.
Containment Capping Clay Liner Low-Moderate: Minimizes surface water infiltration,
controls erosion and surface water runoff, and prevents direct contact of human and ecological receptors.
Compared to a GCL, a clay liner may be more permeable, more susceptible to leaks, and can require
more maintenance, QA/QC testing, and upkeep over time as a result. Subject to desiccation cracking.
High: Requires labor and materials,
logistics planning. Capping material would need regular care and
maintenance, must meet compaction standards, and subject to testing. Other
locations at site (non-rad) have been capped previously.
Moderate capital costs
associated with capping material care and maintenance, requires
recurring inspection and repairs. Minimal cost difference
compared with GCL after all tests and additional maintenance
are considered.
No. Not as effective as GCL
and higher cost may be associated with more frequent
maintenance, testing, and repairs. For same containment
option, GCL is likely more reliable.

Geosynthetic clay liner (GCL) Moderate-High: Effective for minimizing surface water infiltration, controlling erosion and surface water
runoff, and prevents direct contact of human and ecological receptors. Considered more effective than a
traditional clay liner due to higher impermeability, fewer leaks, and less maintenance required.
High: Requires labor and materials, logistics planning. Capping material
would need regular care and maintenance. Other locations at site (non-
rad) have been capped previously.
Moderate capital costs associated with capping material
care and maintenance, requires recurring inspection and repairs.
Minimal cost difference compared with clay liner.
Yes: Considered in conjunction with institutional
controls. More reliable than a clay liner.

Table 6. (continued).
Final Feasibility Study 62 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
General Response Action Remedial Technology Process Option Effectiveness Evaluation Implementability Evaluation Relative Cost Evaluation Retained? Considerations Excavation and Disposal Excavation, Disposal, & Backfilling Confirmation Soil Sampling High: Physically removes contaminated soil & debris, transports impacted materials off-site, and replaces with clean backfill soil from an on-site source. After remediation is complete, direct exposure to risks/hazards are eliminated. Would reduce the potential of human health/environmental risks from direct contact, incidental ingestion, or inhalation of radionuclide soils. Confirmation soil sampling and a magnetometer (or FIDLER/GM) survey would confirm all radiological material and trench debris had been removed.
High: Easy to implement and commonly used at other sites. Moderate to High cost associated with excavation, disposal and backfill, soil survey and confirmation sampling.
Yes. Removes soil and restores the excavated area with clean soil.
Distance to off-site disposal facility; Compliance with Federal transportation regulations; Confirmation of backfill source on-site. Magnetometer or other geophysical survey
Clean soil backfill from an on-site source
Excavation, Sorting, Screening, & Disposal
Confirmation Soil Sampling High: Physically removes the contaminated soil and debris from the trench, sorts and screens the excavated material on-site to remove contaminated soil and debris (i.e., metal tubes), transports impacted material to an off-site disposal facility, and returns clean non-radiologically impacted soil to the trench. After remediation is complete, direct exposure to risks/hazards are eliminated. Would reduce the potential of human health/environmental risks from direct contact with tubes. On-site sorting and screening of soil and debris would be performed to remove material that is radiologically-impacted. Confirmation soil sampling and a magnetometer (or FIDLER/GM) survey would confirm all radiological material and trench debris above screening limits had been removed.
Low to High: Easy to implement the excavation, may be difficult to implement sorting and screening given the high cost associated with these process options.
High cost associated with mobilization and demobilization of sorting and screening technology.
Yes. Removes contaminated media and restores the excavated area with original fill material.
Distance to off-site disposal facility; Compliance with Federal transportation regulations; Cost of transporting sorting and screening technologies to the site.
Sorting & Screening of Contaminated Soil & Debris
Return clean soil to trench
Treatment In-Situ Soil Treatment Cementitious Solidification and Stabilization
Moderate-High: Solidification and stabilization of impacted soils and debris eliminates leaching and migration of radionuclides from the soil and is effective for treating constituents that cannot be degraded into inert forms. Contaminant exposure is reduced through the injection of Portland cement or acrylamide grout into soil and debris. This technique has been shown to reduce water infiltration and exposure rate.
Moderate to high: Soil stabilization using cement grout is a commonly used technique to treat low-level radiological waste.
Moderate cost associated with high-pressure injections and equipment needs.
Yes. Once the cement grout has solidified, the mobility of radionuclides in soil has been reduced. Considered in conjunction with institutional controls.
Would need to incorporate both QC testing (pilot test) prior to injection operations and geotechnical testing during and after injections.
Notes: Shading indicates that the remedial technology and/or process option will not be retained for further evaluation.

Final Feasibility Study 63 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Table 7. Alternatives Summary and Evaluation Comparison.
Evaluation Criteria Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5 Alternative 6
No Action Land Use Controls Capping and LUCs Excavation, Disposal, & Backfilling Excavation, Sorting, Screening, & Disposal Soil Stabilization
Threshold Criteria
Overall Protection of Human Health and the Environment
Does not provide overall protection to human health or the environment. Does not reduce or control potential radiological exposure to soil or
debris. Impacted materials would not be removed, reduced, or controlled.
A low level of protection to human health is provided by reducing the potential for radiological exposure in soil and debris. However,
radiologically-impacted materials are not eliminated or reduced, and the impact on the environment remains the same.
Capping of TR-5 and TR-6 would provide protection to human health and the environment by providing a physical barrier capable of
eliminating direct contact to or exposure by current and future receptors from radiologically-impacted soil.
Excavation of radiologically-impacted soil and debris in trenches TR-5 and TR-6 provides protection to human health and the
environment by preventing direct contact to or external exposure from contaminated soil and radiological debris.
Excavation of radiologically-impacted (above screening limits) soil and debris in trenches TR-5 and TR-6 provides protection to human health and the
environment by preventing direct contact to or external exposure from contaminated soil and radiological debris.
Pressure-injecting grout into TR-5 and TR-6 would provide protection to human health and the environment by limiting direct
contact to or exposure by current and future receptors from radiologically-impacted waste.
Compliance with ARARs ARARs are not met with the No
Action alternative, as no remedy would be implemented.
The chemical-specific ARARs for
Restricted (Industrial) (10 CFR 20.1403) use is met. Planning will
be required to comply with all additional chemical-, location-, and action-specific ARARs.
The chemical-specific ARARs for
Restricted (Industrial) (10 CFR 20.1403) use is met. Planning will
be required to comply with all additional chemical-, location-, and action-specific ARARs.
The chemical-specific ARARs for
Unrestricted (Residential) (10 CFR 20.1402) use is met. Planning will
be required to comply with additional chemical-, location-, and action-specific ARARs.
The chemical-specific ARARs for
Unrestricted (Residential) (10 CFR 20.1402) use is met. Planning will be
required to comply with all additional chemical-, location-, and action-specific ARARs.
The chemical-specific ARAR for
Restricted (Industrial) (10 CFR 20.1403) use is met. Planning will
be required to comply with all additional chemical-, location-, and action-specific ARARs.
Balancing Criteria
Long-Term Effectiveness and Permanence The No Action alternative is not effective or permanent for reducing
radiological COCs over time, aside from natural radioactive decay.
Potential exposure risks associated with radiological COCs would
remain with no controls or long-term management plan.
Alternative 2 provides a low level of long-term effectiveness and
permanence through the use of LUCs. Radiologically-impacted
materials would remain in the trenches and the risk of human
receptor exposure through potentially complete pathways would remain indefinitely.
Alternative 3 would achieve long-term effectiveness and permanence
through a GCL cap at TR-5 and TR-6, combined with LUCs. Capping
material would require routine maintenance and inspection by a
work crew.
Alternative 4 would achieve long-term effectiveness and permanence
through the physical removal of radiologically-impacted soil and
debris from TR-5 and TR-6.
Alternative 5 would achieve long-term effectiveness and permanence through the
physical removal of radiologically-impacted soil and debris (above screening
limits) from TR-5 and TR-6.
Alternative 6 would achieve long-term effectiveness and permanence
through cement grouting of soil and debris at TR-5 and TR-6. LUCs
would also be implemented. Integrity of the grout would require
periodic maintenance and inspection by a work crew.
Reduction of Mobility, Toxicity, Volume, or
Mass
The No Action alternative does not employ any treatment that would
reduce the toxicity, mobility, volume or mass of impacted
material. Natural attenuation processes may reduce radiological COCs over time, but no monitoring will be performed.
Alternative 2 does not provide a reduction in toxicity, mobility,
volume, or mass, and radiological COCs would remain in soil and
debris.
Alternative 3 would permanently reduce the mobility of radiological
COCs in soil through erosion and surface water control. However, the
toxicity, volume, and mass of radiological COCs in soil would not be reduced.
Alternative 4 would permanently reduce the toxicity, mobility,
volume, and mass of radiological COCs via the physical removal of
impacted soil and debris.
Alternative 5 would permanently reduce the toxicity, mobility, volume, and mass of
radiological COCs via the physical removal of impacted soil and debris (above
screening limits).
Alternative 6 would permanently reduce the mobility of radiological
COCs in soil and debris through erosion and surface water control.
However, the toxicity, volume, and mass of radiological COCs in soil would not be reduced.
Short-Term Effectiveness No activities would be implemented
that would present potential short-term exposure risks to human health
or the environment.
Would result in minimal exposure
risks to industrial workers or other human receptors via institutional
controls.
Implementation of GCL caps,
combined with LUCs, would result in an immediate reduction in
potential exposure to site industrial workers.
Implementation of Alternative 4
would be immediately effective upon excavation of impacted soil
and debris, but removal activities may result in minimal exposure risks to the construction/industrial workers. Controls will be put in
place.
Implementation of Alternative 5 would be
immediately effective upon excavation of impacted materials, but removal activities
may result in minimal exposure risks to the construction /industrial workers. Controls will be put in place.
Implementation of soil stabilization,
combined with LUCs, would result in an immediate reduction in
potential exposure to site industrial workers.
Implementability Alternative 1 is implementable, in that no action would be taken. Alternative 2 is considered technically feasible, and services
and materials should be readily available. Requires administrative planning.
Installation of GCL caps and LUCs is technically feasible, and services
and materials for both should be readily available. Requires administrative planning and design of GCL cap.
Alternative 4 is technically implementable via standard
excavation practices and technology. Excavation activities should not interfere with ongoing operations at DPG.
Alternative 5 is technically implementable via standard excavation practices and
technology. Excavation activities should not interfere with ongoing operations at DPG. Implementing the technology used for sorting and screening of soil and debris
on-site may not be feasible given that UU/UE is achievable with Alternative 4 at
a lower cost.
Alternative 6 is technically feasible, and services and materials for high-
pressure injection of cement grout should be available. Testing, including pilot test, and geotechnical testing would be required, as well as
administrative planning.
Cost No Cost $167,000 $383,000 $593,000 $1,439,000 $487,000

Final Feasibility Study 64 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Modifying Criteria
State Acceptance This criterion evaluates the technical and administrative issues and concerns the State of Utah may have regarding each of the alternatives. This criterion will be addressed in the Decision Document once comments on the Feasibility Study and Proposed Plan have been received. Community Acceptance This criterion evaluates the issues and concerns the public may have regarding each of the alternatives. As with State Acceptance, this criterion will be addressed in the Decision Document once comments on the Feasibility Study and Proposed Plan have been received.
Notes: RACER® software utilized to develop the cost estimates.
All costs are estimated to an accuracy of +50 percent to -30 percent (per the USEPA Guide to Developing and Documenting Cost Estimates During the Feasibility Study, dated July 2000).

Final Feasibility Study 65 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Table 8. Cost Analysis of Remedial Alternatives.
Alternatives Assumptions Inputs Total Cost Capital Costs Total O&M and Periodic Costs Present Worth Value
Timeframe: 30 years*
Alternative 1 - No Action No Action None $0 $0 $0 $0
Alternative 2 - Land Use Controls
Administrative LUC (Site use controls, Remedial Design,
LUCIP, Long-Term Stewardship Plan, LUCIP meetings), Signs, Inspections; Engineering Controls (Fencing around both trenches individually or both trenches as one)
1 Remedial Design (medium complexity)
1 LUCIP Plan (medium complexity)
1 LTS Plan (medium complexity) 2 LUCIP meetings 4 signs Annual Inspections
$167,000 $146,000 $19,000 $161,000
Alternative 3 - Containment of TR-5 and
TR-6 and LUCs
Capping (RCRA Hazardous Waste GCL), Administrative LUC (Site use controls, Remedial Design, LUCIP, Long-Term Stewardship Plan, LUCIP meetings), Signs, Inspections; Engineering Controls (Fencing around both trenches individually or both trenches as one)
RCRA C cap (2)
Protective cover minimum of 3 ft cap design 120 ft × 70 ft (8,400 ft2 for TR-5 and TR-6)
40-mil HDPE geomembrane 36-inch protective cover Safety Level D (PPE)
$383,000 $ 156,000 $116,000 $383,000
Alternative 4 - Excavate, Off-Site Disposal, and Backfill with Clean Soil
Excavate both TR-5 and TR-6, Temporary containment for excavated materials, Confirmation soil sampling/radiological
survey, Backfill with certified clean material, Restore surface vegetation, Disposal at ES-Clive disposal facility, No associated
O&M or periodic costs
Documentation, planning, and meetings Excavate a total of 1,000 CY from both trenches
Excavate to a depth of 7 ft bgs Trucked to ES-Clive for disposal (approx. 80 miles)
Backfill with certified clean material
$593,000 $593,000 $0 $593,000
Alternative 5 - Excavate, Sort, Screen, and
Off-Site Disposal
Excavate both TR-5 and TR-6, Temporary containment for excavated materials, Mobilization and Demobilization equipment, On-site radiological screening, Confirmation soil
sampling/radiological survey, Backfill with certified clean material, Restore surface vegetation, Disposal at ES-Clive
disposal facility, No associated O&M or periodic costs
Documentation, planning, and meetings Mobilization and demobilization of soil screening
technology Excavate a total of 1,000 CY from both trenches
Excavate to a depth of 7 ft bgs Sort and Screen 1,000 CY of material
Assume 20% containment Trucked to ES-Clive for disposal (approx. 80 miles)
$1,439,000 $1,439,000 $0 $1,439,000
Alternative 6 – Soil Stabilization
High-pressure injection of grout into both TR-5 and TR-6, Pilot test and geotechnical testing, Administrative LUC (Site use controls, LUCIP, Long-Term Stewardship Plan, LUCIP meetings), Signs, Inspections; Engineering Controls (Fencing
around both trenches individually or both trenches as one)
Cement grout injected under pressure across surface area of 1,782 ft2
Injected to a depth of 10 ft bgs Injection radius of influence 6 ft in diameter
Pilot test and geotechnical testing
$487,000 $454,000 $29,000 $481,000
Notes:
Periodic and O&M costs are estimated over 30 years. Total cost represents the rounded present worth value considering a discount rate of 1.5% for 30 years. Expected accuracy range of -30 percent to +50 percent. Costs are rounded to nearest $1,000 per EPA guidance. *All costs incurred in Year 1 and Year 2 for Alternatives 4 and 5.

Final Feasibility Study 66 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
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Final Feasibility Study A-1 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Appendix A
Characterization Report (included on CD)

Final Feasibility Study A-2 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
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Final
Characterization Report
Area 2 of SWMU-11
Dugway Proving Ground,
Dugway, Utah
Prepared for: U.S. Army Environmental Command

Prepared by: North Wind Services, LLC

February 2020 Rev. 0

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RPT-020121-001 Rev. 0
Final
Characterization Report Area 2 of SWMU 11
Dugway Proving Ground
Dugway, Utah

February 2020
Prepared for: U.S. Army Environmental Command 2455 Reynolds Road JBSA Fort Sam Houston, Texas 78234
Prepared by: North Wind Services, LLC. 1425 Higham Street Idaho Falls, Idaho 83402

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Characterization Report iii North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
CONTENTS 1
INTRODUCTION ........................................................................................................................... 1 2
1.1 Scope of Work .................................................................................................................... 1 3
SITE BACKGROUND INFORMATION ....................................................................................... 1 4
2.1 Physical Description ........................................................................................................... 1 5
2.2 Environmental and Site Characteristics .............................................................................. 1 6
2.2.1 Geology ................................................................................................................... 1 7 2.2.2 Hydrogeology ......................................................................................................... 2 8
2.3 Summary of Prior Site Investigations ................................................................................. 2 9
2.3.1 2005 Phase II Investigation ..................................................................................... 2 10 2.3.2 2014 Investigation ................................................................................................... 3 11
2.3.3 2016 Investigation ................................................................................................... 4 12
RADIOLOGICAL CHARACTERIZATION .................................................................................. 4 13
3.1 Radiological History ........................................................................................................... 4 14
3.2 Radiological Characterization Data Review ....................................................................... 5 15
3.2.1 2005 Phase II Radiological Data ............................................................................. 5 16 3.2.2 2014 Radiological Data........................................................................................... 6 17
3.2.3 2016 Radiological Data........................................................................................... 6 18
3.3 Data Usability ..................................................................................................................... 7 19
3.4 Radiological Contaminants of Concern .............................................................................. 8 20
3.5 COC Extent and Characteristics ......................................................................................... 9 21
3.5.1 TR-6 COC Extent and Characteristics .................................................................... 9 22 3.5.2 TR-5 COC Extent and Characteristics .................................................................... 9 23
DETERMINATION OF DERIVED CONCENTRATION GUIDELINE LEVELS (DCGLs) ..... 10 24
4.1 Applicable or Relevant and Appropriate Requirements ................................................... 10 25
4.2 Modeled Radiological Contaminants of Concern ............................................................. 10 26
4.3 Conceptual Site Model ...................................................................................................... 11 27
4.3.1 Critical Groups ...................................................................................................... 11 28
4.3.2 Exposure Pathways ............................................................................................... 12 29 4.3.3 Conceptual Model of the Source ........................................................................... 12 30
4.4 RESRAD Onsite Input Parameters ................................................................................... 12 31

Characterization Report iv North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
4.5 Soil DCGL Development .................................................................................................. 13 32
4.6 Groundwater Pathway Evaluation .................................................................................... 14 33
4.7 Site-Specific DCGLs ........................................................................................................ 14 34
4.8 DCGLEMC (Area Factors) .................................................................................................. 15 35
4.9 DCGL Sensitivity and Uncertainty Analysis .................................................................... 15 36
MARSSIM CLASSIFICATIONS ................................................................................................. 17 37
SURVEY UNIT IDENTIFICATION ............................................................................................ 18 38
SUMMARY AND CONCLUSIONS ............................................................................................ 19 39
REFERENCES .............................................................................................................................. 20 40
FIGURES 41
Figure 1. Site Location. ............................................................................................................................... 23 42
Figure 2. Site Layout. .................................................................................................................................. 24 43
Figure 3. 2005 Phase II Investigation Sample Locations. ........................................................................... 25 44
Figure 4. 2014 Non-Intrusive Investigation Results. .................................................................................. 27 45
Figure 5. 2016 Investigation Sample Locations. ......................................................................................... 29 46
Figure 6. TR-5 Cross-Sections. ................................................................................................................... 31 47
Figure 7. TR-5 and TR-6 Plan View, 2016 Investigation. .......................................................................... 33 48
Figure 8. Simplified Conceptual Model of Waste Distribution. ................................................................. 35 49
Figure 9. Classification and Survey Units, Area 2, SWMU-11. ................................................................. 36 50
TABLES 51
Table 1. COC screening for SWMU-11 (Area 2) 2016 soil data. ............................................................... 39 52
Table 2. COC screening for SWMU-11 (Area 2) 2016 debris data. ........................................................... 41 53
Table 3. RESRAD ONSITE metabolic and behavioral parameters. ........................................................... 42 54
Table 4. Radionuclide travel time to the aquifer. ........................................................................................ 42 55
Table 5. Soil DCGLs for the Resident Farmer Scenario. ............................................................................ 43 56
Table 6. Soil DCGLs for the Industrial Worker Scenario. .......................................................................... 43 57

Characterization Report v North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Table 7. TR-5 Area Factors for the Residential Farmer.............................................................................. 44 58
Table 8. TR-6 Area Factors for the Residential Farmer.............................................................................. 44 59
Table 9. TR-5 Area Factors for the Industrial Worker................................................................................ 45 60
Table 10. TR-6 Area Factors for the Industrial Worker. ............................................................................. 45 61
Table 11. Uncertainty analysis results. ....................................................................................................... 46 62
Table 12. MARSSIM suggested areas for survey units. ............................................................................. 46 63
APPENDICES 64
Appendix A Pb-210/Po-210 Laboratory Information 65
Appendix B RESRAD ONSITE Parameter Values 66
Appendix C DCGL Sensitivity and Uncertainty Analysis 67

Characterization Report vi North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
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Characterization Report vii North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
ACRONYMS AND ABBREVIATIONS 69
ALARA as low as reasonably achievable 70
bgs below ground surface 71
CERCLA Comprehensive Environmental Response, Compensation and Liability Act 72
CFR Code of Federal Regulations 73
COC contaminant of concern 74
COPC contaminant of potential concern 75
cpm counts per minute 76
CSM conceptual site model 77
CY cubic yards 78
DCF dose conversion factor 79
DCGL Derived Concentration Guideline Level 80
DCGLEMC Derived Concentration Guideline Level Elevated Measurement Comparison 81
DoD Department of Defense 82
DPG Dugway Proving Ground 83
DSR dose-to-source ratio 84
DWMRC Utah Division of Waste Management and Radiation Control 85
EPA United States Environmental Protection Agency 86
FIDLER Field Instrument for the Detection of Low Energy Radiation 87
FS Feasibility Study 88
ft feet 89
ft2 square feet 90
GM Geiger Mueller 91
GPR ground penetrating radar 92
HSA Historical Site Assessment 93
LTM long-term maintenance 94
LUC land use control 95
m2 square meters 96

Characterization Report viii North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual 97
mg/kg milligrams per kilogram 98
mg/L milligrams per liter 99
MoU Memorandum of Understanding 100
mR/hr milliroentgen per hour 101
mrem/yr millirem per year 102
MS metal sample 103
MW monitoring well 104
NaI sodium iodide 105
North Wind North Wind Services, LLC 106
NRC U.S. Nuclear Regulatory Commission 107
PCB polychlorinated biphenyl 108
pCi/g picocuries per gram 109
PDF parameter distribution function 110
RCRA Resource Conservation and Recovery Act 111
RFI RCRA Facility Investigation 112
RI Remedial Investigation 113
SB soil boring 114
SOR sum of ratios 115
SS soil sample 116
SVOC semi-volatile organic compound 117
SWMU Solid Waste Management Unit 118
TCLP Toxicity characteristic leaching procedure 119
TDS total dissolved solids 120
TR trench 121
VOC volatile organic compound 122
µR/hr microroentgen per hour 123

Characterization Report 1 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
INTRODUCTION 124
North Wind Services, LLC (North Wind) has prepared this Characterization Report for Area 2 of Solid 125 Waste Management Unit (SWMU) 11 at Dugway Proving Ground (DPG). DPG is located in Tooele 126
County, Utah, and currently serves as the Army’s designated major range test facility for chemical and 127 biological defense. This Characterization Report was developed for the U.S. Army Environmental 128 Command under Contract No. W9124J-18-D-0007, Delivery Order W9124J18F0088. 129
1.1 Scope of Work 130
Area 2 of SWMU 11 is a radiological disposal area of concern that records indicate has never been 131 licensed by the U.S. Nuclear Regulatory Commission (NRC). During 2016, the Department of Defense 132 (DoD) and the NRC finalized a memorandum of understanding (MoU) for the coordination of response 133
actions for DoD sites containing radioactive material (NRC-DoD MoU, 2016). Pursuant to the MoU, the 134 remaining investigation and remediation activities at Area 2 of SWMU 11 are being addressed under the 135 Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). 136
This Characterization Report (1) summarizes the site conditions and prior investigations at Area 2 of 137 SWMU 11; (2) reviews the existing data set to ensure it is adequate and useable to support the planned 138 Feasibility Study (FS); and (3) develops Derived Concentration Guideline Levels (DCGLs) for soil in 139 trenches TR-5 and TR-6 at Area 2 of SWMU 11 consistent with 10 Code of Federal Regulations (CFR) 140 Part 20, Subpart E, as referenced in the 2016 MoU (NRC-DoD MoU, 2016). 141
SITE BACKGROUND INFORMATION 142
2.1 Physical Description 143
DPG covers approximately 840,000 acres in Tooele County in western Utah. DPG is bordered to the 144
northeast by the Cedar Mountains and to the north-northwest by Wendover Air Force Range. SWMU-11, 145 also known as DPG-011 and the East Granite Holding Area, is located in the remote southwest portion of 146 DPG and lies within a small canyon on the east side of Granite Mountain (Figure 1). SWMU 11 is 147
divided into two distinct areas: Area 1 and Area 2. Area 1 of SWMU 11 consists of three closed trenches 148 (TR-1, TR-2, and TR-3) running roughly east-west along the north side of the canyon and a fourth 149 backfilled trench (TR-4) running north-south. Area 1 of SWMU-11 was previously evaluated and closed 150
under Resource Conservation and Recovery Act (RCRA) and corrective action requirements of the Utah 151 Division of Waste Management and Radiation Control (DWMRC). Area 2 (0.86 acres) of SWMU 11 is 152 the radiological disposal area and consists of two trenches (TR-5 and TR-6) and the area adjacent to the 153 trenches. Area 2 previously contained a CONEX container; however, it was determined to be 154 radiologically clear and was removed in 2017 (Marsh, 2017). Figure 2 shows the Area 2 boundary and 155 trench locations. Available evidence indicates that radiological materials were stored in the CONEX 156 container and disposed in trenches TR-5 and TR-6 as early as the mid-1950s, although specific records 157 regarding materials disposed at Area 2 of SWMU 11 are limited. 158
2.2 Environmental and Site Characteristics 159
2.2.1 Geology 160
SWMU-11 is located at the mouth of a small, northeast-trending colluvial valley along the eastern side of 161 Granite Mountain. The general topography at SWMU-11 is gently sloping down to the east, with an 162 average elevation of 4,375 feet (ft) above mean sea level. The valley is flanked to the south by a small 163

Characterization Report 2 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
ridge of granite that extends from the main Granite Mountain area, and to the north and west by granite 164 outcroppings characteristic of Granite Mountain. To the east, the valley is open to the broad expanse of 165
the Dugway Basin. Granite Mountain is an isolated, north-south trending mountain block approximately 166 8 miles long by 6 miles wide. The southern two-thirds of the mountain are dominated by dark colored 167 gneiss and gneissic granite with a thin sliver of schists and phyllites at the extreme southern end. 168 The northern one-third of the mountain is made up of intrusive leuco-granitic rocks that form a 169 gradational contact with the gneissic granite to the south. Quaternary-aged lacustrine, alluvium, and 170 colluvium deposits are present along the flanks of Granite Mountain, including the small valley where 171 SWMU-11 is located. Away from the mountain, the surrounding basin floor consists of aeolian sand and 172 silt deposits and Quaternary-aged playa and lacustrine sediments associated with deposits of ancient Lake 173 Bonneville and older pluvial lakes (Parsons, 2009). 174
2.2.2 Hydrogeology 175
Groundwater in the area of SWMU-11 is part of the Dugway Valley aquifer system. Groundwater in this 176
region is generally characterized by high total dissolved solids (TDS) and very flat hydraulic gradients. 177 However, the flanks of Granite Mountain, including the SWMU-11 site, constitute a local recharge zone 178 for basin groundwater. In these localized zones, groundwater is deeper and of higher quality than 179
groundwater beneath the basin floor. As groundwater flows from the local recharge area toward the basin 180 floor, it becomes increasingly laden with dissolved mineral constituents, and the quality of groundwater is 181 greatly diminished. Depth to groundwater near the eastern boundary of SWMU-11 is approximately 61 ft 182
below ground surface (bgs) based on water-level measurements from MW-01. An attempt to install a 183 second groundwater well in the western portion of SWMU-11 near TR-5 did not reach saturated 184 conditions but rather encountered competent granite bedrock from 72.5 ft bgs to the terminal drilling 185 depth of 90 ft bgs. Groundwater flow at SWMU-11 is likely to the east or northeast, based on the local 186 topographic gradient present at the site (Parsons, 2009). 187
Due to the overall low quality of groundwater in the western DPG region, there have been no potable 188 water resources developed in the Granite Mountain area. A non-potable water supply well is located 189 6 miles west-northwest of SWMU-11 and is reportedly “very salty” and provides water only for hand 190 washing and toilet flushing purposes at the U.S. Air Force Strategic Training Range Complex west of 191 Granite Mountain. Another non-potable water well, located approximately 4 miles northwest of 192 SWMU-11, is used only for dust suppression. Based on the laboratory TDS measurement of 1,770 193
milligrams per liter (mg/L) from the groundwater samples collected at SWMU-11 (well MW-01), the 194 local groundwater would be Utah Class 2 drinking water quality groundwater (Parsons, 2009). 195
2.3 Summary of Prior Site Investigations 196
The 1996 Phase I Investigation at SWMU 11 (Parsons, 1996) only addressed Area 1 and did not include 197 any activities in Area 2. The investigation of Area 2 began in 2005 during the Phase II RCRA Facility 198 Investigation (RFI) of SWMU-11 (Parsons, 2009). While investigating the known trenches (TR-1 through 199 TR-4) and surrounding area with geophysical and radiological scans, two additional burial trenches on the 200
west side of TR-4 were discovered and subsequently designated as TR-5 and TR-6. 201
2.3.1 2005 Phase II Investigation 202
During the Phase II investigation (Parsons, 2009), the following activities were completed in Area 2: 203
• Magnetometer survey; 204
• Radiological survey using scanning measurements and direct measurements; 205

Characterization Report 3 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
• Collection of four surface soil (0 to 0.5 ft bgs) samples from TR-5 (SS40 - SS43) and two surface soil 206 samples from TR-6 (SS44 and SS45) for laboratory analysis of metals, gross alpha, gross beta, 207 gamma spectroscopy, and Strontium-90. 208
• Collection of one material sample from TR-5 (MS4/MS4A – metal remnant of drum material) for 209 laboratory analysis of metals, gross alpha, gross beta, gamma spectroscopy, isotopic uranium, isotopic 210 thorium, and Strontium-90. 211
• Collection of one material sample from TR-6 (MS2 – solidified sand from inside a corroded drum) 212 for analysis of metals, volatile organic compounds (VOCs), semivolatile organic compounds 213 (SVOCs), and dioxins/furans. 214
• Excavation of one test pit (EP15) to investigate potentially buried wastes in TR-6. One soil sample 215 was collected from the base of the test pit (10 ft bgs) and analyzed for metals, VOCs, SVOCs, and 216
dioxins/furans. 217
• Drilling of one soil boring (SB06) and collection of one subsurface soil sample to characterize 218
subsurface soil downgradient of Area 2. The soil sample was analyzed for VOCs, perchlorate, metals, 219 gross alpha, gross beta, gamma spectroscopy, and Strontium-90. 220
The magnetometer survey identified anomalies in TR-5 and TR-6. Additionally, anomalous radioactivity 221 was measured at both TR-5 and TR-6. The Phase II results identified that TR-6 contained various types of 222 debris, including small metal tubes that had low levels of radioactivity consistent with Cesium-137. Soils 223 surrounding these materials were at background radiation levels; however, in the absence of more 224 conclusive laboratory analysis, the waste in TR-6 was considered unidentified. A localized area of highly 225 elevated radioactivity was present at TR-5. Due to the hazards associated with the area, intrusive activities 226 were not completed. Due to the presence of these uncharacterized and unidentified materials in TR-5 and 227
TR-6, further investigation of the Area 2 radiological portion of SWMU-11 was recommended. 228
Phase II sample locations are documented in Figure 3. Further discussion of the Phase II radiological 229
assessment is provided in Section 3.2.1. The Phase II report (Parsons, 2009) did not specifically address 230 the non-radiological chemical results from TR-5 and TR-6 samples, which included detections of metals, 231 SVOCs, and dioxins/furans. 232
2.3.2 2014 Investigation 233
In 2014, non-intrusive portions of the Remedial Investigation (RI)/FS Work Plan were completed at Area 234 2 of SWMU 11 (Cabrera, 2014). This included surficial gross gamma radiological scans and geophysical 235
(Schondstedt magnetometer and ground penetrating radar [GPR]) scans across the area (Figure 4). 236
TR-5 was delineated by both the geophysical and radiological surveys as a surface area of approximately 237 440 square feet (ft2), with approximately 2 ft of soil cover and extending approximately another 4 ft in 238
depth beyond the covering soil. Surface gamma emitting radioactive material was detected at TR-5. 239
Visual inspection of the TR-6 area showed some surface trash consisting of metal tubes and possible soil 240 piles 1 ft high to 1-½ ft high by 8 to 10 ft long. Some metal was detected in these low soil mounds. Buried 241
metal is interpreted to be scattered over an area approximately 12 ft by 16 ft. This suggests that trash was 242 spread out and then covered with a thin layer of soil. Radar scanning crossed through the area of TR-6; 243 however, the radar energy did not penetrate through the salty soil in this location. Therefore, little 244
information was gained on TR-6 from the GPR scan. 245

Characterization Report 4 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
The combination of radiological and geophysical investigation results confirmed and delineated the TR-5 246 boundaries. There were no indications of surface elevated gross gamma activity on or around TR-6 or 247
outside of the TR-5 boundary based on the radiological investigation. Although the TR-6 geophysical 248 investigation was hampered by soil conditions, the results indicate a surface area of approximately 12 by 249 16 ft of shallow soil mounds covering areas of debris. 250
2.3.3 2016 Investigation 251
In 2016, intrusive portions of the RI/FS Work Plan were completed at Area 2 of SWMU 11 252 (Cabrera, 2016). The following activities were completed: 253
• Identification of 10 soil borings locations in TR-5 and five soil boring locations in TR-6. Each boring 254 location included a surface soil and subsurface soil sample for laboratory analysis of VOCs, SVOCs, 255
metals, gamma spectroscopy, isotopic uranium, Strontium 90, Tritium, and Carbon 14. 256
• One soil sample was collected for toxicity characteristic leaching procedure (TCLP) analysis of 257
VOCs, SVOCs, metals, pesticides, herbicides, polychlorinated biphenyls (PCBs), reactive sulfide, 258 and reactive cyanide. 259
• One debris sample was collected for analysis of gamma spectroscopy, isotopic uranium, isotopic 260 thorium, isotopic plutonium, isotopic polonium, 226Ra, and 90Sr. 261
• Soil cores were scanned with a Geiger Mueller (GM) pancake probe. 262
• Soil boring locations were evaluated with downhole gamma logging using a sodium iodide (NaI) 263 detector. 264
The 2016 sampling locations are depicted on Figure 5. The 2016 investigation report concluded that there 265 is radioactive contamination in TR-5 soil exceeding established screening criteria (Cabrera, 2016). There 266 were no soil results that exceeded screening criteria in Trench TR-6. However, previous test pitting 267 activities in TR-6 have uncovered several drums and debris, some of which contain small amounts of 268 radioactivity. There were no exceedances for any chemical samples (i.e., VOCs, SVOCs, or metals) above 269 the TCLP regulatory limits presented in 40 CFR 261.24. Therefore, the report concluded that it is unlikely 270 that any wastes generated from the excavation of the trenches will result in hazardous or “mixed” waste. 271 Because the Phase II chemical data from TR-5 and TR-6 had not been considered in a similar fashion, 272
North Wind conducted a review of Phase II chemical data and noted the arsenic result of 155 milligrams 273 per kilogram (mg/kg) for MS02 (TR-6; solidified sand from inside a drum). Considering the 274 concentration of arsenic in the drum contents, during implementation of a future remedy at Area 2 of 275
SWMU 11, TCLP analysis of the contents of drums within TR-6 may be warranted. 276
RADIOLOGICAL CHARACTERIZATION 277
3.1 Radiological History 278
In the DPG RCRA Facility Application, SWMU-11 was one of the seven reported radioactive landfills. 279 Historic records regarding radiological materials handling were summarized in the 2009 Phase II RFI 280 (Parsons, 2009). Specific records regarding radiological materials disposed at SWMU-11 are limited. The 281 East Granite Holding Area (e.g., SWMU-11) is not identified in the available literature as being 282 associated with the testing of radiological munitions conducted at DPG in the 1950s and 1960s. Historical 283
inspection records indicate that buried wastes in the SWMU-11 area consisted primarily of “contaminated 284

Characterization Report 5 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
rags and papers.” Inspection records from the U.S. Atomic Energy Commission indicate that low level 285 radioactive waste materials were repackaged for sea disposal in the Able Area. Waste from this activity 286
may have also been disposed at the DPG burial area corresponding to SWMU-11 after the sea disposal 287 program was discontinued. 288
Radioactive waste materials from laboratory activities in other areas of DPG were stored in a CONEX 289 container at SWMU-11 to protect individual storage containers from the elements. Materials stored in the 290 CONEX container included Tritium and Carbon-14. In March 1980, contaminated glassware was 291 removed from the CONEX by the DPG radiation safety officer and disposed at an offsite location. During 292 the 2005 Phase II investigation, no waste remained in the CONEX container (Parsons, 2009). The 293 CONEX container was determined to be radiologically clear and was removed in 2017 (Marsh, 2017). 294
In June 2000, DPG notified the NRC about SWMU-11. During a limited survey of the area conducted in 295 September 2000, NRC personnel were unable to detect any radioactivity significantly above background. 296 In March 2001, the NRC stipulated that any required decommissioning activities at SWMU-11 could take 297
place under the radioactive materials license currently held by DPG. However, in March 2006, the NRC 298 notified DPG that the NRC would evaluate if a new license was necessary to conduct decommissioning 299 activities under the current radioactive materials license (for possession of sealed sources associated with 300
an irradiator). During 2016, the DoD and the NRC finalized a MoU for the coordination of response 301 actions for DoD sites with radioactive materials (NRC-DoD MoU, 2016). Pursuant to the MoU, the 302 remaining investigation and remediation activities at Area 2 of SWMU 11 are being addressed under 303
CERCLA. 304
The 2014 Radiological Assessment (Cabrera, 2014) states that based on available historical records for 305 activities in the Avery Area (i.e., SWMU-41), Cobalt-60 was considered to be a contaminant of potential 306 concern (COPC) at SWMU 11. Available records indicate the Cobalt-60 was used only in sealed sources, 307 making it unlikely that any materials contaminated with Cobalt-60 were disposed at SWMU 11. Records 308 indicate that all Cobalt-60 sealed sources were moved off-site (i.e., off DPG property) after their use. 309 Cobalt-60 has not been detected in any of the investigations at SMWU-11. 310
The 2014 report also notes that radium-containing parts and devices are common on military installations. 311 It may be present in military items as a result of its luminescent properties; instrument dials, gauges, and 312 watches painted with radium containing paint are common. Consequently, it was included as a COPC for 313 SWMU-11. 314
3.2 Radiological Characterization Data Review 315
3.2.1 2005 Phase II Radiological Data 316
The Phase II investigation surface scans identified an area of anomalously elevated radiological activity at 317 TR-5. As noted in the Phase II report (Parsons, 2009), this area was also conspicuously devoid of 318 vegetation and was marked by a slight topographic depression. Gamma exposure rate measurements 319 ranged from 420 microroentgen per hour (µR/hr) at the center of the area to 50 µR/hr at a distance of 3 ft. 320 Background radiation levels (approximately 30 µR/hr) were observed approximately 6 feet away from 321
this point. Additional field measurements taken directly over the area with a Field Instrument for the 322 Detection of Low Energy Radiation (FIDLER) (measuring gamma radiation) showed readings up to 323 575,000 counts per minute (cpm). A GM pancake probe (measuring beta radiation) produced readings of 324
1,200 cpm. Background radiation levels for these instruments at SWMU-11 were between 25,000 and 325 28,000 cpm for the FIDLER and 75 to 125 cpm for the GM Pancake probe. Approximately 4 to 6 inches 326 of soil was scraped from the area with a shovel, and the exposure rate over the spot increased to 327 approximately 2 milliroentgen per hour (mR/hr) (2,000 µR/hr) or about five times that observed prior to 328

Characterization Report 6 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
soil removal. The soil over the anomalous area was not radioactive itself but was instead covering buried 329 radioactive waste material under the area. The scraped soil was placed back over the area and 330
radioactivity returned to the original exposure rate reading of approximately 420 µR/hr. 331
While the field measurements identified elevated activity, the Phase II soil data generally did not. The 332 Phase II sampling included six surface soil samples (SS40-SS45) and one subsurface soil sample (SB06) 333 collected for laboratory analysis. Aside from a single detection of Strontium-90 (4.4 picocuries per gram 334 [pCi/g] in SS42 – TR5), all of the reported Phase II radiological soil data results were within twice the 335 average background levels. 336
The Phase II investigation included sampling of metallic debris from TR-5 (sample MS04/MS04A; 337 0.25 ft bgs). This sample had gamma spectroscopic characteristics similar to those of the surface anomaly. 338 Based on the analytical results, the metal (MS04/MS04A) was concluded to be a ferrous metal that had 339 been contaminated with Strontium-90. The source, depth, and quantity of material was not determined 340 (Parsons, 2009). 341
Based on the field screening of metal tube debris sample MS03 (TR-6; 7 ft bgs), it was noted that the 342 gamma radiation shared a peak on the gamma spectrum with Cesium-137. Due to uncertainties with 343 respect to the contents of the metallic cylinders, they were not shipped for laboratory analyses. 344
In summary, the Phase II investigation detected an area of anomalously elevated radiation and identified 345 potential radiological contaminants of concern (COCs) (i.e., Strontium-90 at TR-5 and Cesium-137 at 346 TR-6) based on field screening and/or laboratory analytical results. However, aside from a single 347
Strontium-90 result, the limited number of surface soil samples did not show any appreciable radiological 348 impacts. 349
3.2.2 2014 Radiological Data 350
The 2014 investigation (Cabrera, 2014) confirmed the Phase II surface scanning results. No elevated 351 surface activity was identified at TR-6. Elevated readings were confirmed in TR-5, with maximum 352 activities in the southern half of TR-5 (Figure 4). No laboratory samples were collected during this 353 investigation. 354
3.2.3 2016 Radiological Data 355
The 2016 investigation included 15 boring locations (including 10 at TR-5 and five at TR-6). At each 356 location, core scanning and downhole gamma logging were used. In addition, 34 soil samples and one 357 debris sample were collected for confirmatory laboratory analyses (Cabrera, 2016). 358
Soil core scans exhibited elevated radioactivity (i.e., at least twice the background levels) only at borehole 359 locations 14 (0 to 1-ft interval) and 15 (0 to 1-ft and 1 to 2-ft intervals) at TR-5. These two borings are 360 located in the southern half of TR-5, which is consistent with prior investigations that identified that area 361
as having elevated field screening results. 362
Figure 6 depicts a cross-section view of downhole gamma logging data at TR-5. Figure 7 depicts the 363 downhole gamma logging data and inferred extent of impact in plan view. Downhole gamma logging 364
showed that boreholes 14 and 15 (i.e., the biased locations within Trench TR-5) clearly had elevated 365 radioactivity. The majority of the radioactivity appeared to be within the top 3 or 4 ft of material. There 366 are also elevated activities found in the intervals below 4 ft bgs. Boreholes 1, 3, 8, and 9 have higher 367 readings from 4 to 8 ft bgs. Boreholes 2, 4, and 7 have higher readings from 1 to 5 ft bgs, with boreholes 368 2 and 4 possibly going deeper. Boreholes 2, 8, and 13 were located on the approximate western edge of 369

Characterization Report 7 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
TR-5. There are also elevated activities found in the intervals below 4 ft bgs; however, these are possibly 370 due to “shine” from the higher activity material above or different background radiation levels associated 371
with fill material inside the trench. 372
Downhole gamma logging showed no indication of elevated radioactivity in TR-6 boreholes 5, 6, 11, and 373 12. All readings at all depths were less than 9,000 cpm. TR-6 Borehole 10 is located within the TR-6 374 footprint on the northern end; the highest downhole gamma logging result was 10,504 cpm at the 5 to 6-ft 375 interval, and the upper 6 ft of material displayed radioactivity greater than 9,000 cpm. This borehole was 376 located directly next to a known metal anomaly found during the geophysical survey. It is likely that the 377 slightly elevated readings are associated with the metal anomaly. Previous investigations in this trench 378 found metallic debris containing small amounts of low-level radioactivity. 379
The 2016 laboratory analytical results generally corroborate the gamma scanning results in that the highest 380 detected radionuclide concentrations most frequently occurred at TR-5 boreholes 14 and 15 (which also 381 had the most elevated radioactivity during field scans). Bismuth-214, Lead-214, Radium-226, and 382 Strontium-90 concentrations at SB15 were one to two orders of magnitude greater than concentrations in 383 other borings. Section 3.4 presents a summary of analytical data for Area 2 of SWMU-11. 384
The six highest concentrations of Cesium-137 occurred in TR-6, which supports the Phase II field 385
screening result that identified possible Cesium-137 in debris sample MS03. A summary of 2016 soil data 386 is provided in Table 1. Table 2 provides 2016 debris sample results. 387
3.3 Data Usability 388
The identification of COCs from the 2005 and 2014 investigations was based on radiological field 389
screening (2005 and 2014), limited laboratory analytical data (2005 only), and the limited historical 390 records of materials disposed at Area 2 SWMU 11. A discussion of the data quality for these prior events 391 is presented in the prior investigation reports (Parsons, 2009 and Cabrera, 2014). During the 2016 392
investigation, substantially more laboratory analytical data were collected. The 2016 soil was analyzed by 393 ALS Laboratories for gamma spectroscopy (Method 713R13), Strontium-90 (724R11), Tritium and 394 Carbon-14 (704R10), and isotopic Uranium, Thorium, and Plutonium (714R12). All detected isotopes 395
were requested to be reported for the gamma spectroscopy analyses. 396
The 2005 radiological laboratory results (and detection limits) were reviewed and compared to the 2016 397 data set and the screening criteria discussed in Section 3.4. With the exception of Strontium-90, the 2005 398
laboratory results were less than the 2016 results. The Strontium-90 result (199 pCi/g from sample 399 MS-04) was greater than the 2016 detection (19.2 pCi/g). However, this does not create any uncertainty 400 because Strontium-90 was retained as a COC (Section 3.4). Cobalt-60 was not reported in the 2016 data 401 set but was reported as “non-detect” in the 2005 data. The reported detection limit of Cobalt-60 402 (0.19 pCi/g) was less than the dose compliance concentration based on 10 mrem/yr for a residential land 403 use scenario (1.6 pCi/g); thus, it is not a COC. The 2016 laboratory analytical data are concluded to be 404 conservative and complete, and it is unlikely that potentially significant radionuclides have been missed. 405
An evaluation of 2016 field and laboratory data quality was included in the Final Report for Area 2 406
SWMU 11 (Cabrera, 2016). The discussion notes that false positive results are potential for Cobalt-56, 407 Manganese-54, Europium-54, Niobium-94, and Antimony-125. Given the uncertainty with respect to the 408 materials that were disposed in Area 2 SWMU 11, no detected analytes were eliminated from the data set, 409
even if they were potential analytical artifacts. This approach is conservative and ensures no potentially 410 significant radionuclides are omitted. 411
The 2016 data set was, therefore, concluded to be of sufficient quality to use for its intended purpose of 412
defining the nature and extent of radiological impacts at TR-5 and TR-6. 413

Characterization Report 8 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
3.4 Radiological Contaminants of Concern 414
The radiological data described above were used to define COCs. Tables 1 and 2 present the radiological 415 constituents detected in the 2016 soil and debris samples, respectively. As a conservative screening to 416
identify COCs, the maximum detection in soil or debris was compared to the dose compliance 417 concentration protective of a residential land use scenario and dose limit of 10 millirem per year 418 (mrem/yr). The dose compliance concentrations were obtained using the U.S. Environmental Protection 419
Agency (EPA) web-based calculator (https://epa-dccs.ornl.gov/cgi-bin/dose_search). 420
The soil (Table 1) and debris (Table 2) concentrations were also compared to twice the average site-421 specific background concentrations. Site specific background data were established in the Phase II report 422 (Parsons, 2009) and background comparisons and frequency of detection screenings were used during the 423 RI process at SWMU 11. Background comparisons are frequently used as a screening protocol for 424 inorganics and naturally occurring radionuclides in CERCLA evaluations. There are various approaches 425 for conducting background comparisons, including simple techniques as well as more advanced statistical 426 techniques. Comparing the maximum detected site concentrations to twice the average background is a 427 simple approach that is commonly used. Ultimately, Postassium-40 was the only constituent removed 428 from the final list of COCs (combined list from soil and debris) for Area 2 SWMU 11 based on the 429 comparison to background. 430
The following constituents had concentrations less than the screening criteria and/or background but were 431 nonetheless included as COCs: 432
• Cesium-137 was included as a COC due to the Phase II investigation field screening results that 433
suggested it may be present inside the cylindrical tubes identified as debris in TR-6. 434
• Lead-210 was included as a COC due to the unexpected Polonium-210 detection in the 2016 debris 435
sample, and the likelihood that it was present in secular equilibrium (see the laboratory explanation in 436 Appendix A). 437
• Carbon 14 was included as a COC due to the maximum detection in SB15 co-located with the area of 438 maximum activity, and given the fact that Carbon-14 contaminated materials (e.g., glassware in the 439 former CONEX box) have historically been documented at SWMU-11. 440
The following four constituents were included as COCs because they had non-detect results that exceeded 441 dose compliance concentrations: 442
• Cobalt-56 had a non-detect result of 126 pCi/g as compared to a dose compliance concentration of 443 1.22 pCi/g). 444
• Iron-59 had a non-detect result of 5.2 pCi/g as compared to a dose compliance concentration of 445
3.8 pCi/g). 446
• Niobium-95 had a non-detect result of 7.9 pCi/g as compared to a dose compliance concentration of 447
6.4 pCi/g). 448
• Thorium-227 had a result of 8.1 pCi/g as compared to a dose compliance concentration of 1.3 pCi/g). 449
These non-detect results are not included on Table 1 but can rather be found in the Final Phase II RI 450 Report (Cabrera, 2016). The elevated reporting limits for these constituents all occurred at location SB15, 451 which is the location of the highest field scanning results as well as the greatest radionuclide 452
concentrations based on the laboratory data. 453

Characterization Report 9 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
The final list of COCs includes: Actimum-228, Bismuth-212, Bismuth-214, Carbon-14, Cesium-137, 454 Cobalt-56, Iron-59, Lead-210, Lead-212, Lead-214, Niobium-94, Niobium-95, Protactinium-234m, 455
Plutonium-242, Polonium-210, Radium-226, Strontium-90, Thorium-229, Thorium-230, Thorium-232, 456 Thorium-234, Thorium-227, Uranium-232, Uranium-234, Uranium-235, and Uranium-238. Several of 457 these constituents (e.g., Bismuth-214, Protactinium-234, etc.) are short-lived daughter products that have 458 half-lives of minutes, hours, or days. The determination of derived guideline concentration levels will be 459 based on parent radionuclide plus daughters. 460
3.5 COC Extent and Characteristics 461
The extent and characteristics of radiological COCs are distinct between the two trenches at Area 2 of 462
SWMU-11. 463
3.5.1 TR-6 COC Extent and Characteristics 464
At TR-6, there were no field scanning results to indicate any substantially elevated radioactivity at land 465 surface. Also, the radiological laboratory soil results were all uniform, with no particular sample greatly 466 exceeding others. The only indication of radiological concern at TR-6 is the potential presence of 467 Cesium-137 that was initially identified in the Phase II debris sample MS03. Small metal tubes were 468 identified at a depth of 7 ft bgs during the excavation of test pit EP15 (Figure 3). When scanned in the 469 field, several of the metal tubes had gamma peaks consistent with Cesium-137. Although 2016 470
concentrations of Cesium-137 in soil were less than the dose compliance concentration screening levels 471 (Table 1), the 2016 soil samples from SB-05, SB-10, SB-11, and SB-12 did have Cesium-137 472 concentrations that were greater than those documented in TR-5. Lastly, the 2016 downhole gamma 473
logging results at SB-10 had slightly elevated responses. This borehole was located directly next to a 474 known metal anomaly found during the geophysical survey (Figure 5). It is possible that the slightly 475 elevated readings could be associated with the metal anomaly. Based on the available data, the metallic 476
debris in TR-6 may contain Cesium-137. Such debris may occur throughout TR-6, and particularly in the 477 areas where geophysical anomalies were identified (Figure 5). The waste volume was estimated by 478 Cabrera (2016) as 165 cubic yards (CY) with approximate dimensions of 40 ft long by 20 ft wide by 6 ft 479 deep. However, the approximate dimensions of 40 ft long by 20 ft wide by 6 ft deep for TR-6 results in 480 178 CY. Therefore, for the DCGL development, the larger volume of 178 CY was used since this results 481 in conservative (i.e., lower) DCGLs. 482
3.5.2 TR-5 COC Extent and Characteristics 483
At TR-5, the SB-15 laboratory results generally corroborate the downhole gamma logging results 484 presented in Section 3.2.3. Maximum concentrations of Radium-226 (3,040 pCi/g), Strontium-90 485 (19.2 pCi/g), Bismuth-214 (2,100 pCi/g), Niobium-94 (8.9 pCi/g), and Lead-214 (2,200 pCi/g) were 486 reported at the 0 to 1-ft interval of location SB-15. As an example of COC extent, Radium-226 results 487
exceeding two times average background levels (2.6 pCi/g) occurred at locations SB-13 (4.84 pCi/g, 0 to 488 1 ft), SB-02 (3.77 pCi/g, 5 to 6 ft), SB-14 (7.26 pCi/g, 0 to 1 ft), SB-15 (3,040 pCi/g, 0 to 1 ft and 489 40.7 pCi/g, 5 to 6 ft), and SB-04 (14.5 pCi/g, 5-6 ft). 490
In three locations having elevated surface gamma readings, the radiological screening was conducted after 491 excavating down 1 ft to determine if the contamination was caused by a discrete source, or if it was 492 distributed throughout the area of elevated gamma activity. A discrete source for the contamination was 493
not found; therefore, the radiological contamination was concluded to be relatively homogeneous 494 (within the areas of elevated gamma results) (Cabrera, 2016). 495

Characterization Report 10 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
In summary, the field screening and laboratory results indicate that COCs at TR-5 are elevated within the 496 trench, with detections exceeding background in surface and subsurface soil and the highest 497
concentrations in the surface intervals at SB-15 and SB-14. The estimated excavation waste volume for 498 TR-5 was 194 CY (Cabrera, 2016), assuming approximate dimensions of 46 ft long by 17 ft wide by up to 499 7 ft deep. However, the approximate dimensions of 46 ft long by 17 ft wide by 7 ft deep for TR-5 results 500 in 203 CY. Therefore, for the DCGL development, the larger volume of 203 CY was used since this 501 results in conservative (i.e., lower) DCGLs. 502
DETERMINATION OF DERIVED CONCENTRATION GUIDELINE 503 LEVELS (DCGLs) 504
The purpose of this section is to describe the methods used to calculate site-specific DCGLs for soil in 505
TR-5 and TR-6 at SWMU 11 and to provide the results of the calculations. The dose modeling methods 506 and assumptions are described and the results of the DCGL calculations provided. This includes the 507 selection of the critical group, exposure scenario, conceptual site model (CSM) for soil, RESRAD 508
ONSITE input parameters, and analysis results. 509
4.1 Applicable or Relevant and Appropriate Requirements 510
Applicable or relevant and appropriate requirements for radiological COCs in soil at the site are identified 511 in 10 CFR 20.1402 (Radiological Criteria for Unrestricted Use) and 10 CFR 20.1403 (Criteria for License 512
Termination Under Restricted Conditions). Provisions of both 10 CFR 20.1402 and 10 CFR 20.1403 513 require that the annual dose to an average member of the critical group not exceed 25 mrem/yr, and that 514 the residual radioactivity be reduced to levels that are as low as reasonably achievable (ALARA). 515 However, unlike 10 CFR 20.1402, 10 CFR 20.1403 allows this dose limit to be achieved through the use 516 of engineering and land use controls (LUCs), with the added requirement that the annual dose does not 517 exceed 100 mrem/yr should those institutional controls fail or if they are no longer in effect. 518
4.2 Modeled Radiological Contaminants of Concern 519
Several COCs listed in Section 3.4 are short-lived radionuclides that would not persist in the waste 520 without a long-lived parent. These radionuclides include Co56, Fe-59, and Nb-95. These radionuclides 521 were not modeled for DCGLs since they would not be present in the waste due to decay. 522
Additional short-lived radionuclides are listed as COCs in Section 3.4 that have long-lived parent 523 radionuclides. These radionuclides include Ac-228, Bi-212- Bi-214, Pb-212, Pb-214, Pa-234m, Po-210, 524 Th-234, and Th-227. These short-lived radionuclides were included in the decay chains of the long-lived 525
parent radionuclides that were identified as a COC. 526
Based on the radiological COCs presented in Section 3.4, the following radionuclides and radionuclide 527 decay chains (i.e., identified as +D) were modeled for the DCGLs: 528
• C-14, 529
• Cs-137 + D (i.e., Ba-137m), 530
• Nb-94, 531
• Pb-210 + D (i.e., Bi-210, Po-210), 532
• Pu-242 + D (i.e. U-238 decay series), 533

Characterization Report 11 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
• Ra-226 + D (i.e., Rn-222, Po-218, Pb-214, Bi-214, Po-214, Pb-210, Bi-210 and Po-210), 534
• Sr-90 + D (i.e., Y-90), 535
• Th-229 + D (i.e., Ra-225, Ac-225, Fr-221, At-217, Bi-213, Tl-209, Pb-209 and Po-213), 536
• Th-230 + D (i.e., Ra-226 decay series), 537
• Th-232 + D (i.e., Ra-228, Ac-228, Th-228, Ra-224, Rn-220, Po-216, Pb-212, Bi-212, Tl-208 and 538
Po-212), 539
• U-232 + D (i.e., Th-228, Ra-224, Rn-220, Po-216, Pb-212, Bi-212, Tl-208 and Po-212), 540
• U-234 + D (i.e., Th-230 decay series), 541
• U-235 + D (i.e., Th-231, Pa-231, Ac-227, Fr-223, Ra-223, Rn-219, Po-215, Pb-211, Bi-211, Tl-207, 542
Po-211 and Th-227), and 543
• U-238 + D (i.e., Th-234, Pa-234m, Pa-234 and U-234 decay series). 544
The dose conversion factors (DCFs) in the isotope library used in RESRAD ONSITE (Kamboj et al., 545 2018) assumes that progeny isotopes with radioactive half-lives less than 180 days are in secular 546 equilibrium with their parent (i.e., an isotope with a half-life greater than 180 days). Consequently, the 547 dose contributions from the short-lived progeny of the long-lived radium nuclides are automatically 548 included in the calculations. In addition, RESRAD ONSITE automatically calculates the ingrowth 549 concentrations of the longer-lived progeny in the decay chains and accounts for the dose contributions 550 from these nuclides. 551
The entire list of COCs were used at both TR-5 and TR-6 to develop DCGLs, regardless of where the 552 COC was identified. The unity rule, also termed the sum-of-ratios (SOR) (as provided in Section 4.5), 553 would be used for any sample obtained from either TR-5 or TR-6 for those radionuclides detected in the 554 sample. Therefore, determining DCGLs for all COCs identified at both trenches ensures that if a 555
radionuclide were detected at TR-6 that was not previously found during characterization activities, a 556 DCGL would be available. However, the only difference in the DCGLs for TR-5 and TR-6 is the volume 557 of soil brought to the surface, and thus, the areal extent of the resulting 0.15-meter (6-inch) soil layer. 558
4.3 Conceptual Site Model 559
This section presents the CSM for the DCGL development. This includes a description of the critical 560 groups, exposure pathways, and conceptual model of the source. 561
4.3.1 Critical Groups 562
In general, DCGLs were developed for two dose scenarios: (1) residential (i.e., unrestricted), which 563 requires no LUCs (or long-term maintenance [LTM]) based on 25 mrem/yr; and (2) industrial 564 (i.e., restricted release), which occurs after loss of LUCs or LTM based on 100 mrem/yr. The RESRAD 565 ONSITE computer model (Kamboj et al., 2018) was used for all modeling for the development of the 566 DCGLs. 567
The Resident Farmer was selected as the critical group for DCGL development for unrestricted release 568 under 10 CFR 20.1402. A Resident Farmer critical group results in more conservative DCGLs (i.e., lower 569 concentrations) than an industrial use critical group due primarily to the increased dose from the 570 consumption of food grown onsite and occupancy time considerations. 571

Characterization Report 12 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
An Industrial Worker was selected as the critical group for DCGL development for restricted release 572 under 10 CFR 20.1403. The Industrial Worker is considered to be representative of the likely future use 573
of the Dugway site. 574
4.3.2 Exposure Pathways 575
A Resident Farmer was assumed to move onto the site, build a home, and establish a farm for raising 576 crops and livestock for a 30-year period. The Resident Farmer scenario assumes exposure to residual 577 radioactivity through several exposure pathways, including: 578
• Direct radiation; 579
• Inhalation of re-suspended dust; 580
• Direct ingestion of soil; 581
• Ingestion of food from crops grown in contaminated soil and irrigated with site water; 582
• Ingestion of water from a well contaminated by water percolated through the contaminated area; and 583
• Ingestion of meat and milk from livestock raised using on-site well water and feed grown within the 584 contaminated soil that has been irrigated with site water. 585
An Industrial Worker was assumed to work at the site 8 hours per day, 250 days per year for 30 years. 586
The Industrial Worker was assumed to work outdoors at the site for 7 hours per day and is indoors for 587 1 hour per day. The Industrial Worker scenario assumes exposure to residual radioactivity through several 588 exposure pathways, including: 589
• Direct radiation; 590
• Inhalation of re-suspended dust; 591
• Direct ingestion of soil; and 592
• Ingestion of water from a well contaminated by water percolated through the contaminated area. 593
The Radon exposure pathway is not included in the dose assessment for the Resident Farmer or Industrial 594 Worker scenarios, which is consistent with the guidance provided in NUREG-1757, Volume 2, Appendix 595 J. 596
4.3.3 Conceptual Model of the Source 597
The Resident Farmer and Industrial Worker scenarios assume that the entire volume of contaminated soil 598
in a trench is exhumed and spread over the ground surface, resulting in a 6-inch contaminated soil layer 599 (Figure 8). This is a conservative assumption based on Appendix J of NUREG-1757, where a dose 600 assessment strategy for buried waste is provided. The use of this strategy simplifies the analysis and 601
provides a conservative estimate of the radionuclide DCGLs. 602
4.4 RESRAD Onsite Input Parameters 603
The RESRAD ONSITE computer code was run using deterministic parameters. The parameters were 604 selected by first categorizing the parameters as behavioral, metabolic, or physical in accordance with the 605
recommendations in NUREG/CR-6697. Consistent with the guidance in NUREG-1757, Section I.6.4.2, 606

Characterization Report 13 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
the behavioral and metabolic parameters were assigned the mean of the parameter distribution function 607 (PDF) recommended in NUREG-5512, Volume 3, when available. The metabolic and behavioral 608
parameters are listed in Table 3. 609
The preferred method for the selection of physical parameters was the use of site-specific values 610 determined by measurement or analysis or from literature values based on the site soil type. If site-611 specific information was not available, a parameter priority ranking method was used to guide the 612 parameter selection process. 613
The method for selecting the physical parameters that were not site-specific depended on their relative 614 effect on the calculated dose. NUREG/CR-6697, Attachment B, provides a detailed analysis of the 615 physical parameters. The result was a ranking of the parameters as Priority 1, Priority 2, or Priority 3. 616
Priority 1 parameters generally have the greatest effect on dose, while Priority 3 parameters generally 617 have the least. The parameter priority rankings are provided in NUREG/CR-6697, Attachment B, Table 618 4-2, and are also noted in this report in Appendix B, Tables B-1 and B-2, for the parameter values 619
selected for the Resident Farmer and Industrial Worker scenarios. 620
Priority 3 parameters that were not site-specific were assigned the RESRAD ONSITE deterministic 621 default values. Priority 1 and 2 parameters that were not site-specific were assigned values based on the 622
median or mean value from the PDFs provided in NUREG/CR-6697, Attachment C. 623
The selected RESRAD ONSITE parameter values for the Resident Farmer and the Industrial Worker are 624 provided in Appendix B, Tables B-1 and B-2, respectively. 625
4.5 Soil DCGL Development 626
An initial unit concentration of 1 pCi/g for each radiological COC was used in conjunction with the 627 RESRAD ONSITE input parameters provided in Appendix B. The peak dose to the average member of 628 the critical group, from each radiological COC, was calculated over a 1,000-year period and was defined 629
as the peak dose-to-source ratio (DSR). The DSR, in units of mrem/yr per pCi/g, was then divided into 630 the dose limit of interest (25 mrem or 100 mrem annual dose) to determine the site-specific DCGL for 631 each radiological COC. 632
Each radionuclide-specific DCGL represents the concentration of residual activity, above background, 633 that would result in the dose limit of interest to the average member of the critical group (i.e., 25 or 100 634 mrem annual dose). When multiple radionuclides are present, compliance is addressed using the unity 635
rule. 636
The unity rule, also termed the SOR, is used when multiple radionuclides exhibit unknown or variable 637 relative concentrations throughout the site. The unity rule is considered the default approach for assessing 638
multiple radionuclides in soil against their respective DCGLs. 639
The unity rule, or SOR, is: 640 𝑆𝑆𝑆𝑆𝑆𝑆=�𝐶𝐶1𝐷𝐷𝐶𝐶𝐷𝐷𝐷𝐷1�+�𝐶𝐶2𝐷𝐷𝐶𝐶𝐷𝐷𝐷𝐷2�+⋯+ �𝐶𝐶𝑛𝑛𝐷𝐷𝐶𝐶𝐷𝐷𝐷𝐷𝑛𝑛� 641
where: 642
C = radionuclide concentration (pCi/g) 643
DCGL = derived concentration guideline level (pCi/g). 644

Characterization Report 14 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
4.6 Groundwater Pathway Evaluation 645
Groundwater in the area of SWMU-11 is part of the Dugway Valley aquifer system. Groundwater in this 646 region is generally characterized by high TDS and flat hydraulic gradients. However, the flanks of 647 Granite Mountain (including the SWMU-11 site) constitute a local recharge zone for basin groundwater. 648 In these localized zones, groundwater is deeper and of higher quality than groundwater beneath the basin 649 floor. As groundwater flows from the local recharge area toward the basin floor, it becomes increasingly 650
laden with dissolved mineral constituents, and the quality of groundwater is greatly diminished. 651
Parsons (2009) proposed installing two groundwater monitoring wells (MW01 and MW02). MW02 was 652 located in the western portion of the site closer to Granite Mountain. Several attempts to drill MW02 were 653 unsuccessful due to bedrock conditions encountered that prevented advancement of the MW02 boring to 654 groundwater. As such, the boring, which began as “MW02,” was completed as “SB06,” and a soil 655 (rather than a groundwater) sample was collected at this location (Parsons, 2009). 656
Depth to groundwater at SWMU-11 is approximately 61 ft bgs based on water-level measurements from 657 MW01. Groundwater flow at SWMU-11 is likely to the east or northeast, based largely on the local 658 topographic gradient present at the site (Parsons, 2009). 659
Due to the overall low quality of groundwater in the western DPG region, there have been no potable 660 water resources developed in the Granite Mountain area. Water well WW32, located 6 miles west-661
northwest of SWMU-11, is reportedly “very salty” and provides water only for hand washing and toilet 662 flushing purposes at the U.S. Air Force Strategic Training Range Complex, which is located west of 663 Granite Mountain. Water well WW10, located approximately 4 miles northwest of SWMU-11, is 664
currently used for dust suppression only. Historical information available from the Utah Division of 665 Water Rights indicates that water from well WW10 was not fit for human consumption and was used only 666 for municipal purposes (e.g., boiler feed, fire suppression, and decontamination) at the Granite Peak 667
Installation-2 (GPI-2; SWMU-4) facility. Groundwater quality at SWMU-11 is Class II (drinking water 668 quality) per Utah Administrative Code R317-6-3 (DWQ, 2019), based on the laboratory TDS 669 measurement of 1,770 mg/L from the groundwater sample collected from MW01 (Parsons, 2009). 670
The groundwater pathway was evaluated in the Residential Farmer scenario for SWMU 11, Area 2. 671 Conservative parameter values were used for the groundwater pathway, basing the parameter values for 672 the unsaturated and saturated zones on the typical properties of sand. Table 4 provides the RESRAD 673 ONSITE results for the travel time of radionuclides to the aquifer at SWMU-11, Area 2, based on sand 674 sorption coefficients, as presented in Appendix B. 675
The travel time for all the radiological COCs of interest are greater than the 1,000-year model period. 676 Therefore, the radiological COCs will not migrate to the groundwater during the assessment period. 677 In addition, evidence from the attempt to install MW02 near SWMU 11, Area 2, indicates that the 678
development of a water well in this area of the site may not be possible. Therefore, the groundwater 679 pathway is not a significant contributor to the receptor doses at SWMU 11, Area 2. 680
4.7 Site-Specific DCGLs 681
The soil DCGLs for the Resident Farmer at TR-5 and TR-6 are provided in Table 5. The soil DCGLs for 682 the Industrial Worker at TR-5 and TR-6 are provided in Table 6. 683

Characterization Report 15 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
4.8 DCGLEMC (Area Factors) 684
Area factors were developed in accordance with the Multi-Agency Radiation Survey and Site 685 Investigation Manual (MARSSIM) to evaluate the dose from small areas of elevated activity. The area 686 factors were developed for each CSM by adjusting the size of the contaminated zone and dividing the 687 resulting DCGL for the smaller areas of activity (DCGLEMC) by the applicable site DCGL. Area factors 688
for the excavation scenario were calculated for contaminated zone sizes of 1, 5, 10, and 50 square meters 689
(m2). Larger areas of interest are not necessary since the trench areas are 72.65 m2 for TR-5 and 74.32 m2 690 for TR-6. 691
The elevated trench activity for the DCGL development was assumed to be excavated intact and brought 692
to the surface, with the only modification to “flatten” the material from the trench depths of 2.13 meters 693 (TR-5) and 1.83 meters (TR-6) to the excavation scenario surface soil depth of 0.15 meter. Therefore, the 694 area factors are constrained to a soil averaging depth of 0.15 meter (6 inches). An example use of these 695 area factors would be to evaluate small areas of elevated radionuclides at the bottom of the excavations to 696 determine if additional remediation is necessary. Thus, the constraint that the area factors apply only to an 697 averaging depth of 0.15 meter (6 inches) is reasonable based on the typical sample depth of 0.15 meter 698 (6 inches) for radiological samples in soil. The area factors for the Residential Farmer scenario are 699 provided in Tables 7 and 8 for TR-5 and TR-6, respectively. The area factors for the Industrial Worker are 700 provided in Tables 9 and 10 for TR-5 and TR-6, respectively. 701
The DCGLs for elevated measurement comparison (DCGLEMC) are obtained by multiplying the 702 applicable DCGL by the area factor that corresponds to the actual area of the elevated concentrations of 703
interest. For example, assume that an elevated area (5 m2) of Ra-226 activity is located at the bottom of 704 the TR-5 excavation after remediation. The unrestricted release DCGL for Ra-226 is 7.4 pCi/g (see Table 705 5); therefore, the DCGLEMC for Ra-226 in a 5-m2 area for the unrestricted release would be the DCGL 706
times the 5-m2 area factor, which is 5.1 (see Table 7), resulting in a DCGLEMC of 37.7 pCi/g. Therefore, if 707 the 5-m2 area at the bottom of the excavation, averaged over a depth of 0.15 meter (6 inches), is equal to 708 or less than 37.7 pCi/g, no further remediation of this elevated area is required (assuming no other 709
radionuclides were present in the sample). 710
4.9 DCGL Sensitivity and Uncertainty Analysis 711
DCGL sensitivity and uncertainty analyses were also conducted on the RESRAD models for the Resident 712 Farmer and Industrial Worker scenarios. The details of the sensitivity and uncertainty analysis are 713
provided in Appendix C. A brief summary of the methods and results is provided below. 714
A parameter sensitivity analysis was conducted for the Resident Farmer and Industrial Worker scenarios 715 for Ra-226 at TR-5. Ra-226 was chosen for the sensitivity and uncertainty analysis since it is widely 716 distributed throughout TR-5. Similar parameter sensitivities and uncertainties would be expected for the 717 other COCs for which DCGLs were developed. The parameters considered in the sensitivity analyses 718 were based on those provided in NUREG/CR-6697. The values for each parameter of interest were varied 719
and evaluated at a minimum, midpoint and maximum value in RESRAD-ONSITE. 720
The following parameters were found to have the highest sensitivities in the Resident Farmer scenario: 721
1. Sorption coefficient (Kd) of the contaminated zone; 722
2. Density of the contaminated zone; 723
3. Runoff coefficient; 724

Characterization Report 16 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
4. External gamma shielding factor; 725
5. Fruit, vegetable, and grain consumption rate; 726
6. Soil ingestion; 727
7. Depth of soil mixing layer; 728
8. Depth of roots; 729
9. Indoor time fraction; and 730
10. Evapotranspiration coefficient. 731
The following parameters were found to have the highest sensitivities in the Industrial Worker scenario: 732
1. Sorption coefficient (Kd) of the contaminated zone, 733
2. Density of the contaminated zone, 734
3. Runoff coefficient, 735
4. External gamma shielding factor, 736
5. Soil ingestion, 737
6. Depth of soil mixing layer, and 738
7. Evapotranspiration coefficient. 739
Uncertainty analyses were conducted for the Resident Farmer and Industrial Worker scenarios for the 740
parameters found to be the most sensitive based on the sensitivity analyses. Two uncertainty analyses 741 were run for each of the Resident Farmer and Industrial Worker scenario consisting of (1) parameter 742 uncertainty based on the lower quartile (25%) and upper quartile (75%) of the sensitive parameters based 743
on the RESRAD-ONSITE parameter distributions provided in NUREG/CR-6697, and (2) parameter 744 uncertainty based on sampling of the full RESRAD-ONSITE parameter distributions provided in 745 NUREG/CR-6697. 746
The DCGL results of the uncertainty analyses are summarized in Table 11. The base case DCGL model 747 results based on the deterministic runs are also shown to provide a comparison to the uncertainty results. 748
The full parameter distribution uncertainty results, based on the peak-of-the mean dose distribution, are in 749 agreement with the deterministic base case model results. The peak-of-the-mean DCGLs are considered 750 to be appropriate to compare with the deterministic DCGLs because NRC indicates that when using 751 probabilistic dose modeling, the peak-of-the-mean dose distribution should be used for demonstrating 752 compliance with its License Termination Rule in 10 CFR 20, Subpart E (NUREG-1757). 753
The quantile parameter value uncertainty analyses produced DCGLs that were less than both the 754
deterministic based case model DCGLs and the full parameter distribution uncertainty DCGLs. However, 755 the use of the lower and upper quartiles for the parameter values is considered overly conservative 756 considering the conservatism already built into the conceptual models for the Resident Farmer and 757
Industrial Worker scenarios. 758

Characterization Report 17 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
As noted in Section 4.3.3, the Resident Farmer and Industrial Worker scenarios assume that the entire 759 volume of contaminated soil in a trench is exhumed and spread over the ground surface, resulting in a 760
6-inch contaminated soil layer. This is a conservative assumption based on Appendix J of NUREG-1757, 761 where a dose assessment strategy for buried waste is provided. The use of this strategy simplifies the 762 analysis and provides a conservative estimate of the radionuclide DCGLs. 763
In addition, several additional conservatisms were incorporated into the Resident Farmer and Industrial 764 Worker scenarios. These conservatisms include the assumption that a Resident Farmer would actually be 765 able to develop a well in the area to provide water for farming (see Section 4.6). The Industrial Worker 766 scenario also includes the conservative assumption that the worker would be present at this remote site 767 with no facilities for 8 hours per day, 250 days per year for 30 years (see Section 4.3.2). 768
After consideration of the results of the probabilistic uncertainty analyses, and the conservatism built into 769 the deterministic base case scenarios, it was determined that it is appropriate to use the deterministic base 770 case DCGLs, supported by the peak-of-the-mean DCGLs, for the TR-5 and TR-6 DCGLs. 771
MARSSIM CLASSIFICATIONS 772
MARSSIM requires that areas be initially classified as impacted or non-impacted based on the results of 773 the Historical Site Assessment (HSA). Non-impacted areas have no reasonable potential for residual 774 contamination and require no further evidence to demonstrate compliance with the release criterion. In 775
accordance with previous reports for SWMU 11, Area 2, TR-5, TR-6, and their buffer areas are 776 considered impacted (Parsons 2009; Cabrera 2014; Cabrera 2016). Radioactive materials have been found 777 at both TR-5 and TR-6. In addition, the buffer areas are considered to be potentially impacted due to their 778
proximity to the trenches. 779
Impacted areas are areas that have the potential for containing contaminated material. They can be 780 subdivided into the following three classes: 781
• Class 1 Areas: Areas that have, or had prior to remediation, a potential for radioactive contamination 782 (based on site operating history) or known contamination (based on previous radiological surveys). 783
Note that areas containing contamination in excess of the DCGL prior to remediation should be 784 classified as Class 1 areas. 785
• Class 2 Areas: These areas have, or had prior to remediation, a potential for radioactive contamination 786 or known contamination, but are not expected to exceed the DCGL. To justify changing an area's 787 classification from Class 1 to Class 2, the existing data (from the HSA, scoping surveys, or 788 characterization surveys) should provide a high degree of confidence that no individual measurement 789
would exceed the DCGL. 790
• Class 3 Areas: Any impacted areas that are not expected to contain any residual radioactivity, or are 791 expected to contain levels of residual radioactivity at a small fraction of the DCGL, based on site 792 operating history and previous radiological surveys. Examples of areas that might be classified as 793 Class 3 include buffer zones around Class 1 or Class 2 areas, and areas with very low potential for 794 residual contamination but insufficient information to justify a non-impacted classification. 795
At SWMU 11, Area 2, TR-5 is classified as a Class 1 area. The radionuclides (i.e., specifically Ra-226) in 796 TR-5 would likely exceed the DCGLs based on the reported soil concentrations provided in Cabrera 797 (2016). 798

Characterization Report 18 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
TR-6 is also classified as a Class 1 area. The radionuclides at TR-6 are not likely to exceed the DCGLs; 799 however, as noted in MARSSIM: 800
To justify changing an area's classification from Class 1 to Class 2, the existing data 801 (from the HSA, scoping surveys, or characterization surveys) should provide a high 802 degree of confidence that no individual measurement would exceed the DCGL. 803
According to Parsons (2009), TR-6 contains various types of debris, including small metal tubes that have 804 low levels of radioactivity consistent with Cesium-137 but which remain unidentified in the absence of 805 conclusive radiological analyses. Although the waste in TR-6 was visually inspected and screened during 806 test pit excavation, this material could not be fully identified. MS03, the representative sample of a metal 807 tube, was not sent off-site for laboratory analysis due to uncertainties regarding the use and associated 808 hazards of this item. Therefore, since analytical results are not available to conclusively identify the metal 809 tubes, the waste in TR-6 is considered unidentified. Based on this uncertainty, TR-6 is classified as a 810 Class 1 area. 811
As discussed in Section 2.3.2, Cabrera (2014) conducted a gross gamma surface investigation throughout 812 Area 2 of SWMU 11. The radiological survey area results were combined and overlaid with the TR-5 and 813 TR-6 geophysical results (Figure 4) to confirm the trench boundaries delineated by both investigations. 814
There were no indications of surface radioactive material on or around TR-6 or outside of the TR-5 815 boundary based on this radiological investigation. Therefore, the buffer areas of TR-5 and TR-6 are 816 classified as Class 3 areas. 817
SURVEY UNIT IDENTIFICATION 818
A survey unit is a physical area consisting of land areas of specified size and shape for which a separate 819 decision will be made as to whether that area exceeds the release criterion. 820
To facilitate survey design and ensure that the number of survey data points for a specific site are 821
relatively uniformly distributed among areas of similar contamination potential, the site is divided into 822 survey units that share a common history (or other characteristics), or are naturally distinguishable from 823 other portions of the site. A site may be divided into survey units at any time before the final status 824 survey. For example, HSA or scoping survey results may provide sufficient justification for partitioning 825 the site into Class 1, 2, or 3 areas. However, according to the MARSSIM (NUREG-1575), dividing the 826 site into survey units is critical only for the final status survey. Scoping, characterization, and remedial 827
action support surveys may be performed without dividing the site into survey units. 828
Survey units should be limited in size based on classification, exposure pathway modeling assumptions, 829 and site-specific conditions. The MARSSIM (NUREG-1575) suggested areas for survey units are 830
provided in Table 12. 831
The areal extent of TR-5, TR-6, and the buffer areas are within the recommended MARSSIM survey unit 832 areas provided in Table 12. Therefore, TR-5 and TR-6 are each considered a survey unit. The buffer areas 833 surrounding TR-5 and TR-6 are also considered a survey unit. The survey units are shown in Figure 9 and 834 the areas of the survey unit are provided in Table 12. 835
836

Characterization Report 19 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
SUMMARY AND CONCLUSIONS 837
This Characterization Report summarized the site conditions and prior investigations at Area 2 of SWMU 838 11; reviewed the existing data set to ensure it is adequate and useable to support the planned FS; and 839
developed DCGLs for soil in TR-5 and TR-6 at Area 2 of SWMU 11. 840
The 2016 data set (Cabrera, 2016) was evaluated and concluded to be of sufficient quality to use for its 841 intended purpose of defining the nature and extent of radiological impacts at TR-5 and TR-6. Gamma 842
surface scans of Area 2 (Cabrera, 2014) also indicated that the buffer areas around the trenches did not 843 exhibit elevated activity. 844
Site-specific DCGLs for the radionuclide COCs were developed and are reported in Tables 5 for the 845
Residential Farmer scenario and in Table 6 for the Industrial Worker scenario. 846
In addition, area factors have also been generated to account for contaminated soil areas smaller in size 847 than the areas used in the model. These area factors for the Residential Farmer scenario are presented in 848 Table 7 for TR-5 and in Table 8 for TR-6. The area factors for the Industrial Worker scenario are 849 presented in Table 9 for TR-5 and in Table 10 for TR-6. 850
A sensitivity and uncertainty analysis was also conducted for the Resident Farmer and Industrial Worker 851 scenarios in Section 4.9 and Appendix C. The results of this analysis (Table 11) support the use of the 852 deterministic DCGLs presented in Section 4.7 and Tables 5 and 6. 853
TR-5 and TR-6 were determined to be Class 1 areas with survey units equal to their full areal extent of 854 94 m2 and 68 m2, respectively. The remainder of SWMU-11, Area 2 is a Class 3 buffer area with a survey 855 unit size of 3,328 m2. 856

Characterization Report 20 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
REFERENCES 857
Cabrera, 2014, Final: Implementation of Portions of the Work Plan for Remedial Investigation 858
(RI)/Feasibility Study (FS) for Area 2 of Solid Waste Management Unit (SWMU) 11 859 (Work Plan), Dugway Proving Ground (DPG), Utah. August 2014. 860
Cabrera, 2016, Final Report: Area 2 Solid Waste Management Unit (SWMU) 11 Trenches TR-5 and 861
TR-6, Dugway Proving Ground, Dugway, Utah. September 2016. 862
Code of Federal Regulations, Title 10, Part 20, Subpart E, “Standards for Protection Against Radiation - 863 Radiological Criteria for License Termination.” 864
Code of Federal Regulations, Title 10, Part 20.1402, “Standards for Protection Against 865 Radiation−Radiological Criteria for Unrestricted Use.” 866
Code of Federal Regulations, Title 10, Part 20.1403, “Standards for Protection Against Radiation− 867
Criteria for License Termination Under Restricted Conditions.” 868
Code of Federal Regulations, Title 40, Part 261.24, “Toxicity Characteristic.” 869
DWQ (Division of Water Quality). 2019. “Administrative Rules for Ground Water Quality Protection.” 870 Utah Department of Environmental Quality. R317-6, Utah Administrative Code. July 1, 2019. 871
Kamboj, S., E. Gnanapragasam, and C. Yu, 2018, User’s Guide to RESRAD-ONSITE Code, Version 7.2. 872 ANL/EVS/TM-18/1, Environmental Science Division, Argonne National Laboratory, March 873 2018. 874
Marsh, Geoffrey G., 2017, “Annual Operation Safety Survey (OSSA) for the SWMU-11 site to consider 875
safety and radiological conditions.” Memorandum for Dugway Proving Ground Director 876 Installation Safety, RSO. October 24. 877
NRC-DoD MoU, 2016, “Memorandum of Understanding Between the United States Nuclear Regulatory 878
Commission and the United States Department of Defense for Coordination on CERCLA 879 Response Actions at DOD Sites with Radioactive Materials,” Scott W. Moore, Acting 880 Director Office of Nuclear Material Safety and Safeguards and Maureen Sullivan Deputy 881
Assistant Secretary of Defense (Environment, Safety and Occupational Health). 882
Parsons, 1996, Final Phase I RCRA Facility Investigation Report, Dugway Proving Ground, Dugway, 883 Utah, Parsons Engineering Science, Salt Lake City, Utah, October. 884
Parsons, 2009, Final Phase II RCRA Facility Investigation: SWMU 11 Addendum, Dugway Proving 885 Ground, Dugway, Utah, Parsons Engineering Science, Salt Lake City, UT, August. 886
U.S. Nuclear Regulatory Commission, NUREG-1575, “Multi-Agency Radiation Survey and Site 887 Investigation Manual (MARSSIM),” Revision 1, August 2000, including June 2001 updates. 888
U.S. Nuclear Regulatory Commission, NUREG-1757, “Consolidated Decommissioning Guidance, 889
Characterization, Survey, and Determination of Radiological Criteria,” Volume 2, Revision 1, 890 September 2006. 891
U.S. Nuclear Regulatory Commission, NUREG/CR-6697, ANL/EAD/TM-98, “Development of 892
Probabilistic RESRAD 6.0 and RESRAD-BUILD 3.0 Computer Codes,” November 2000. 893
U.S. Nuclear Regulatory Commission, NUREG/CR-5512, SAND99-2148, Volume 3, “Residual Radioactive 894 Contamination from Decommissioning - Parameter Analysis,” Draft, October 1999. 895

Characterization Report 21 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
FIGURES 896

Characterization Report 22 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
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Characterization Report 23 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
898 From: Cabrera, 2016 899
Figure 1. Site Location. 900
Figure 1 Site Location Map
SWMU 11 Dugway Proving Ground, Utah

Characterization Report 24 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
901 From: Cabrera, 2016 902
Figure 2. Site Layout. 903

Characterization Report 25 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
904 From: Parsons, 2009 905
Figure 3. 2005 Phase II Investigation Sample Locations. 906
Figure 3 Phase II Sample Locations
SWMU 11 Dugway Proving Ground, Utah

Characterization Report 26 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
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Characterization Report 27 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
908 From: Cabrera, 2014 (Note that the Connex box has subsequently been removed). 909
Figure 4. 2014 Non-Intrusive Investigation Results. 910
Figure 4 Non-Intrusive Investigation Results
SWMU 11 Dugway Proving Ground, Utah
TR-6

Characterization Report 28 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
(This page intentionally left blank) 911

Characterization Report 29 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
912 From: Cabrera, 2016 (Note that the Connex box has subsequently been removed). 913
Figure 5. 2016 Investigation Sample Locations. 914
Figure 5 2016 Investigation Sample Locations
SWMU 11 Dugway Proving Ground, Utah

Characterization Report 30 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
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Characterization Report 31 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
916 From: Cabrera, 2016 917
Figure 6. TR-5 Cross-Sections. 918
Figure 6 TR-5 Cross-Sections
SWMU 11 Dugway Proving Ground, Utah

Characterization Report 32 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
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Characterization Report 33 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
920 From: Cabrera, 2016 (Note that the Connex box has subsequently been removed). 921
Figure 7. TR-5 and TR-6 Plan View, 2016 Investigation. 922
Figure 7 TR-5 and TR-6 Plan View 2016 Investigation
SWMU 11 Dugway Proving Ground, Utah

Characterization Report 34 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
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Characterization Report 35 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
924 From: NUREG-1757 925
Figure 8. Simplified Conceptual Model of Waste Distribution. 926

Characterization Report 36 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
927
Figure 9. Classification and Survey Units, Area 2, SWMU-11. 928

Characterization Report 37 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
TABLES 929

Characterization Report 38 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
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Characterization Report 39 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Table 1. COC screening for SWMU-11 (Area 2) 2016 soil data. 931
Analyte Units
Frequency of Detection Range of Detections Maximum Detection
Arithmetic Average of Detections
Dose Compliance Concentration (DL=10)1
Max Detect > DCC?5 2X Average Background2
Max Detect > 2X Background? COC?
Actinium-228 pCi/g 33 / 34 1.68 - 3.74 3.74 2.33 1 Yes 3.6 Yes Yes
Antimony-125 pCi/g 1 / 34 9.8 9.8 9.8 11.2 No NA -- No
Bismuth-212 pCi/g 33 / 34 1.67 - 3.72 3.72 2.52 3.15 Yes 2.4 Yes Yes
Bismuth-214 pCi/g 34 / 34 1.01 - 2100 2100 64.11 0.2 Yes 2.6 Yes Yes
Carbon-14 pCi/g 1 / 34 21 21 21 102 No NA -- Yes3
Cerium-144 pCi/g 1 / 34 -0.032 -0.032 -0.032 69.3 No NA -- No
Cesium-134 pCi/g 8 / 34 0.037 - 0.115 0.115 0.067 2.51 No NA -- No
Cesium-137 pCi/g 19 / 34 0.03 - 1.22 1.22 0.287 5.88 No 2.2 No Yes4
Cobalt-56 pCi/g 20 / 34 0.095 - 0.224 0.224 0.146 1.22 No NA -- No
Europium-152 pCi/g 9 / 34 0.106 - 0.2 0.2 0.153 4.17 No NA -- No
Europium-155 pCi/g 20 / 34 0.09 - 0.171 0.171 0.121 158 No NA -- No
Lead-212 pCi/g 33 / 34 1.89 - 4.02 4.02 2.56 2.64 Yes 3.6 Yes Yes
Lead-214 pCi/g 34 / 34 1.15 - 2200 2200 67.32 0.198 Yes 2.6 Yes Yes
Manganese-54 pCi/g 11 / 34 0.029 - 0.05 0.05 0.039 5.11 No NA -- No
Niobium-94 pCi/g 2 / 34 0.084 - 8.9 8.9 4.49 3.08 Yes NA -- Yes
Potassium-40 pCi/g 33 / 34 16.6 - 32.7 32.7 26.83 2.62 Yes 52.2 No No
Protactinium-234m pCi/g 1 / 34 5.4 5.4 5.4 0.143 Yes NA -- Yes
Radium-226 pCi/g 34 / 34 1.16 - 3040 3040 92.97 0.155 Yes 2.6 Yes Yes
Strontium-90 pCi/g 7 / 34 0.29 - 19.2 19.2 3.68 0.457 Yes NA -- Yes
Thallium-208 pCi/g 33 / 34 0.528 - 1.22 1.22 0.75 1.31 No 1.2 Yes No
Thorium-234 pCi/g 33 / 34 1.68 - 3.86 3.86 2.63 0.151 Yes ND Yes Yes
Tritium pCi/g 2 / 34 0.035 - 0.224 0.224 0.13 60.3 No NA -- No
Table 1. (continued).
Characterization Report 40 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Analyte Units
Frequency of Detection Range of Detections Maximum Detection
Arithmetic Average of Detections
Dose Compliance Concentration (DL=10)1
Max Detect > DCC?5 2X Average Background2
Max Detect > 2X Background? COC?
Uranium-232 pCi/g 34 / 34 2.06 - 3.91 3.91 3.25 0.78 Yes NA -- Yes
Uranium-234 pCi/g 34 / 34 0.9 - 6.4 6.4 1.52 0.151 Yes NA -- Yes
Uranium-235* pCi/g 3 / 34 0.113 - 0.185 0.185 0.146 0.134 Yes ND Yes Yes
Uranium-235+ pCi/g 28 / 34 0.016 - 0.35 0.35 0.072 0.134 Yes ND Yes Yes
Uranium-238 pCi/g 34 / 34 0.78 - 6.7 6.7 1.23 0.149 Yes ND Yes Yes
* U-235 results from method 713R13 + U-235 results from method 714R12
(1) DCC for residential land use scenario (https://epa-dccs.ornl.gov/cgi-bin/dose_search) and adjusted to be protective of 10 mrem/yr dose limit. (2) Site background data from Phase II Investigation (Parsons, 2009). (3) Carbon-14 included as COC due to maximum detection co-located with other COCs and the historic documented presence of C-14 impacted materials at SWMU-11. (4) Cesium-137 included as a COC due to field screening results that indicate it may be present inside the metal tube debris in TR-6. (5) DCC is the dose compliance concentration.

Characterization Report 41 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Table 2. COC screening for SWMU-11 (Area 2) 2016 debris data. 932
Analyte Units Detection
Dose Compliance Concentration (DL=10)1 Detect > DCC? 2X Average Background2 Detect > 2X Background? COC?
Actinium-228 pCi/g 1.23 1 Yes 3.6 No No
Bismuth-212 pCi/g 1.46 3.15 No 2.4 No No
Bismuth-214 pCi/g 1.56 0.2 Yes 2.6 No No
Cesium-137 pCi/g 0.034 5.88 No 2.2 No No
Cobalt-56 pCi/g 0.164 1.22 No NA -- No
Lead-210 pCi/g -- -- -- -- -- Yes3
Lead-212 pCi/g 1.16 2.64 No 3.6 No No
Lead-214 pCi/g 1.57 0.198 Yes 2.6 No No
Plutonium-242 pCi/g 19.7 0.146 Yes NA -- Yes
Polonium-209 pCi/g 740 744 No NA -- No
Polonium-210 pCi/g 3520 5.04 Yes NA -- Yes
Potassium-40 pCi/g 16.6 2.62 Yes 52.2 No No
Radium-226 pCi/g 2.23 0.155 Yes 2.6 No No
Strontium-90 pCi/g 3.7 0.457 Yes NA -- Yes
Thallium-208 pCi/g 0.36 1.31 No 1.2 No No
Thorium-228 pCi/g 0.84 1.25 No NA -- No
Thorium-229 pCi/g 30.6 1.38 Yes NA -- Yes
Thorium-230 pCi/g 0.74 0.154 Yes NA -- Yes
Thorium-232 pCi/g 0.84 0.367 Yes NA -- Yes
Thorium-234 pCi/g 1.83 0.151 Yes ND Yes Yes
Uranium-232 pCi/g 26.2 0.78 Yes NA -- Yes
Uranium-234 pCi/g 0.8 0.151 Yes NA -- Yes
Uranium-238 pCi/g 0.81 0.149 Yes ND Yes Yes
(1) DCC for residential land use scenario (https://epa-dccs.ornl.gov/cgi-bin/dose_search) and adjusted to be protective of 10 mrem/yr dose limit. (2) Site background data from Phase II Investigation (Parsons, 2009). (3) Lead-210 was included as a COC due to the unexpected Po-210 detection in the 2016 debris sample and likelihood that it was present in secular equilibrium (see lab explanation in Appendix A).
933

Characterization Report 42 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Table 3. RESRAD ONSITE metabolic and behavioral parameters. 934
Parameter Units Classification
Inhalation rate m3/yr Metabolic
Fraction of time spent indoors unit-less Behavioral
Fraction of time spent outdoors (on-site) unitless Behavioral
Fruit, vegetable, and grain consumption kg/yr Behavioral
Leafy vegetable consumption kg/yr Behavioral
Milk consumption L/yr Behavioral
Meat and poultry consumption kg/yr Behavioral
Soil ingestion rate g/yr Behavioral
Drinking water intake L/yr Behavioral
935
Table 4. Radionuclide travel time to the aquifer. 936
Nuclide Travel Time to Aquifer (yr)
C-14 1,113
Cs-137 60,506
Nb-94 34,589
Pb-210 58,346
Pu-242 118,820
Ra-226 108,020
Sr-90 3,273
Th-229 691,150
Th-230 691,150
Th-232 691,150
U-232 7,593
U-234 7,593
U-235 7,593
U-238 7,593
937

Characterization Report 43 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Table 5. Soil DCGLs for the Resident Farmer Scenario. 938
Nuclide
TR-5 Dose-To-Source-Ratio (DSR) (mrem/yr per pCi/g)
TR-5
DCGL (25 mrem) (pCi/g)
TR-6 Dose-To-Source Ratio (DSR) (mrem/yr per pCi/g)
TR-6
DCGL (25 mrem) (pCi/g)
C-14 1.43E-02 1,753 1.21E-02 2,070
Cs-137 7.62E-01 33 7.55E-01 33
Nb-94 2.07E+00 12 2.06E+00 12
Pb-210 9.25E-01 27 8.38E-01 30
Pu-242 1.07E-01 234 9.84E-02 254
Ra-226 3.39E+00 7.4 3.26E+00 7.7
Sr-90 5.29E-01 47 4.80E-01 52
Th-229 5.71E-01 44 5.58E-01 45
Th-230 8.07E-01 31 7.74E-01 32
Th-232 4.04E+00 6.2 3.95E+00 6.3
U-232 1.75E+00 14 1.73E+00 14
U-234 1.98E-02 1,261 1.85E-02 1,353
U-235 1.96E-01 128 1.94E-01 129
U-238 5.12E-02 488 4.98E-02 502
Note: Ingrowth of daughter products is included in the analysis. 939
Table 6. Soil DCGLs for the Industrial Worker Scenario. 940
Nuclide
TR-5 Dose-To-Source-Ratio (DSR) (mrem/yr per pCi/g)
TR-5 DCGL (100 mrem) (pCi/g)
TR-6 Dose-To-Source-Ratio (DSR) (mrem/yr per pCi/g)
TR-6 DCGL (100 mrem) (pCi/g)
C-14 1.50E-06 6.68E+07 1.40E-06 71,479,628
Cs-137 5.82E-01 172 5.79E-01 173
Nb-94 1.65E+00 61 1.64E+00 61
Pb-210 3.14E-02 3,188 2.86E-02 3,499
Pu-242 2.33E-02 4,284 2.19E-02 4,564
Ra-226 1.83E+00 55 1.82E+00 55
Sr-90 5.02E-03 19,916 4.94E-03 20,239
Th-229 3.50E-01 285 3.47E-01 288
Th-230 5.00E-01 200 4.97E-01 201
Th-232 2.62E+00 38 2.60E+00 38
U-232 1.39E+00 72 1.38E+00 73
U-234 4.25E-03 23,552 4.10E-03 24,414
U-235 1.46E-01 687 1.45E-01 691
U-238 3.00E-02 3,329 2.98E-02 3,358
Note: Ingrowth of daughter products is included in the analysis. 941

Characterization Report 44 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Table 7. TR-5 Area Factors for the Residential Farmer. 942
Nuclide
Elevated Area of Interest (m2)
1 5 10 50
C-14 16,478 2,143 831 84
Cs-137 11 3.5 2.3 1.4
Nb-94 11 3.4 2.2 1.3
Pb-210 637 185 101 23
Pu-242 11 8.7 7.8 5.5
Ra-226 17 5.1 3.4 1.9
Sr-90 504 124 69 17
Th-229 6.5 3.3 2.4 1.6
Th-230 16 5.5 3.7 2.1
Th-232 12 4.1 2.8 1.6
U-232 11 3.6 2.4 1.4
U-234 6.2 5.1 4.6 3.5
U-235 9.1 3.2 2.1 1.3
U-238 8.5 3.8 2.7 1.7
Note: Ingrowth of daughter products is included in the analysis. 943
Table 8. TR-6 Area Factors for the Residential Farmer. 944
Nuclide
Elevated Area of Interest (m2)
1 5 10 50
C-14 13,959 1,815 704 71
Cs-137 11 3.5 2.3 1.4
Nb-94 11 3.4 2.2 1.3
Pb-210 512 146 79 17
Pu-242 10 8.0 7.2 5.0
Ra-226 16 4.9 3.2 1.9
Sr-90 457 113 62 16
Th-229 6.3 3.2 2.3 1.5
Th-230 16 5.3 3.5 2.0
Th-232 12 4.0 2.7 1.6
U-232 11 3.5 2.4 1.4
U-234 5.8 4.8 4.3 3.3
U-235 9.0 3.1 2.1 1.3
U-238 8.3 3.7 2.6 1.6
Note: Ingrowth of daughter products is included in the analysis. 945

Characterization Report 45 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Table 9. TR-5 Area Factors for the Industrial Worker. 946
Nuclide
Elevated Area of Interest (m2)
1 5 10 50
C-14 31 13 8.9 4.5
Cs-137 11 3.4 2.2 1.3
Nb-94 11 3.4 2.2 1.3
Pb-210 77 38 26 11
Pu-242 5.2 4.3 4.0 3.1
Ra-226 11 3.5 2.3 1.3
Sr-90 12 3.8 2.5 1.5
Th-229 6.8 3.0 2.1 1.4
Th-230 11 3.5 2.3 1.4
Th-232 11 3.4 2.3 1.4
U-232 11 3.5 2.3 1.4
U-234 3.0 2.5 2.3 1.8
U-235 9.0 3.0 2.0 1.3
U-238 7.9 3.1 2.2 1.4
Note: Ingrowth of daughter products is included in the analysis. 947
Table 10. TR-6 Area Factors for the Industrial Worker. 948
Nuclide
Elevated Area of Interest (m2)
1 5 10 50
C-14 29 12 8.3 4.2
Cs-137 11 3.3 2.2 1.3
Nb-94 11 3.4 2.2 1.3
Pb-210 70 35 24 10
Pu-242 4.9 4.1 3.7 2.9
Ra-226 11 3.4 2.3 1.3
Sr-90 12 3.8 2.5 1.5
Th-229 6.7 3.0 1.6 1.3
Th-230 11 3.5 2.3 1.4
Th-232 11 3.4 2.3 1.3
U-232 11 3.5 2.3 1.3
U-234 2.9 2.4 2.2 1.8
U-235 8.9 3.0 2.0 1.3
U-238 7.8 3.1 2.2 1.3
Note: Ingrowth of daughter products is included in the analysis. 949

Characterization Report 46 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Table 11. Uncertainty analysis results. 950
Scenario
DCGL (pCi/g)
Base Case Quantile Uncertainty Full Distribution Uncertainty
Resident Farmer 7.4 4.4 7.5
Industrial Worker 55 51 54
951
Table 12. MARSSIM suggested areas for survey units. 952
Classification Suggested Area Survey Unit Areaa
Class 1 Up to 2,000 m2 94 m2
Class 2 2,000 to 10,000 m2 68 m2
Class 3 No limit ~ 3,328 m2
a. Based on areas presented in Figure 9. 953

Characterization Report A-1 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Appendix A 954
Pb-210/Po-210 Laboratory Information 955

Characterization Report A-2 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
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ALS Group USA, Corp.
225 Commerce DriveFort Collins, CO 80524
T [phone] F [phone]

Right Solutions • Right Partner www.alsglobal.com

February 2, 2017
Greg Bright
Cabrera Services, Inc.
50 Founders Plaza, suite 207 East Hartford, CT 06108

Re: Dugway Proving Ground Sample SWMU11A2-Bias-14-Debris, Pb210
Dear Greg,
The sample in question was received initially for gamma spec analysis, which was later expanded to include Strontium-90, Radium-226 by emanation, Polonium-210, and Isotopic Thorium, Uranium and
Plutonium.
Our internal prescreen for alpha and beta in this sample estimated these activities near or above 500
pCi/g. The Iso U, Th and Pu activities proved to be insignificant re the prescreen alpha. A reduced aliquot
of sample was used for the initial Polonium-210 analysis. Nevertheless, the peak in the alpha spectrum was very large, and tailed into the tracer region of interest, which would cause an unacceptable bias to the
result. The sample was, therefore, re-prepared (in duplicate) using a nitric acid leach of the original
material. The aliquot size was reduced even further, allowing an acceptable spectrum. The duplicate value
matched very well with the sample value (both near 3600 pCi/g). We believe the Polonium-210 results
reported for this sample to be entirely unambiguous.
The Polonium-210 results, owing to it’s relatively short half-life (with respect to the site history) bring up
the question as to which nuclide in the decay chain would account be responsible. The parent nuclide, Pb-
210, is an obvious possibility. However, Pb-210 was not included in the suite of analyses. And,
unfortunately, the original sample and digestates had been disposed prior to these discussions. The only
possible corroboration within the suite of analyses actually performed would be from the gamma spec.
In order to generate a quantified Pb-210 result from the original gamma spectroscopy results, the original
data files for the spectra (raw data and calibration files) would need to be re-run through the instrument
software, but this time including Pb-210 in the gamma library. This was attempted, however the necessary
data files were not able to be recovered. This was due a failure (a few months after the gamma analysis) in
the LIMS server. Additional attempts were made to recover the data from a backup tape, but thus far these attempts have been unsuccessful. So, with only the raw data printouts in hand, the following items may
be noted.
Lead-210 has a gamma emission at 46.5 keV, and a peak at this energy was detected on each of 2 gamma
counts (the sample was counted in duplicate), which used separate detectors. The evidence for the
presence of Pb-210 is very strong, as there are no other “common” nuclides with an emission in this
region. What remains open to question is the quantification of the Pb-210 in the sample. This arises
because the gamma emission at 46.5 keV falls below the efficiency calibration curves for the gamma
spectrometers which were used. The lowest energy nuclide in the efficiency curves is 59.5 keV, which is
the emission for Americium-241. And, the “steepness” of the efficiency versus energy curve in this region
Page 1 of 15

Right Solutions • Right Partner www.alsglobal.com

is considerable, so that energies differing by only 30 keV could see efficiencies differing by up to an order
of magnitude. The lab does not possess a gamma calibration standard that includes Pb-210, or other
nuclides with energies low enough to be of use for this purpose.
Based on the lack of reliable efficiency values for the 46.5 keV peak, the quantitation of Pb-210 can only
be estimated, and even then, this estimate is subject to considerable uncertainty. That being said, a
manual calculation of Pb-210 was performed, based on the raw data printouts from the original analyses,
and making the assumption that the calibration curve could be extrapolated down to the 46.5 keV energy
for Pb-210. These generated values of 1315 pCi/gram on one detector, and 2140 pCi/gram on the other,
i.e. in the duplicate analysis. (Note that the two detectors used differ by a factor of 6x in their efficiencies
for Americium-241, which is at 59.5 keV.) These values, at least, agree to within an order of magnitude
with the Polonium-210 results from the alpha spec. This is reasonably within the range of expected values,
assuming the Polonium-210 and Pb-210 activities to have reached equilibrium.
I hope that these discussions are of help in resolving the issues you are facing, and please contact me if
there is anything more that I can provide.

Sincerely

Project Manager, ALS Ft Collins

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Characterization Report B-1 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Appendix B 957
RESRAD ONSITE Parameter Values 958

Characterization Report B-2 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
(This page intentionally left blank) 959
Table B-1. RESRAD ONSITE Input Parameters for the Resident Farmer Scenario
Characterization Report B-3 North Wind Services, LLC
Area 2 SWMU 11 Dugway, Utah February 2020
RESRAD ONSITE INPUT PARAMETER
Parameter Code Default Value Units Justification Reference
CHANGE TITLES
Internal dose factor library NA NA FGR-11 NA Federal Guidance Report 11 Dose Factors required by NRC. NUREG-1757
External dose factor library NA NA FGR-12 NA Federal Guidance Report 12 Dose Factors required by NRC. NUREG-1757
Cut-off ½ life NA 180 180 days Cut-off for daughter products (progeny) for in-growth calculation. NA
SET PATHWAY
External gamma NA Active Active unitless Site Conceptual Model, Resident Gardener. NA
Inhalation (w/o radon) NA Active Active unitless Site Conceptual Model, Resident Gardener. NA
Plant ingestion NA Active Active unitless Site Conceptual Model, Resident Gardener. NA
Meat ingestion NA Active Active unitless Site Conceptual Model, Resident Gardener. NA
Milk ingestion NA Active Active unitless Site Conceptual Model, Resident Gardener. NA
Aquatic foods NA Active Inactive unitless Site Conceptual Model, Resident Gardener. NA
Drinking water NA Active Active unitless Site Conceptual Model, Resident Gardener. NA
Soil ingestion NA Active Active unitless Site Conceptual Model, Resident Gardener. NA
Radon NA Inactive Inactive unitless NUREG-1757, Vol. 2, Section J.4 states that the Radon pathway should be turned off. NUREG-1757
MODIFY DATA – Soil Concentrations
Activity units NA pCi pCi NA Standard reporting units. NA
Dose units NA mrem mrem NA Standard reporting units. NA
Basic radiation dose limit NA NA 25 mrem/yr NRC TEDE limit for unrestricted site release. 10 CFR 20.1402
Nuclide concentration S(i) NA 1 pCi/g A unit concentration was used as the input value for each COC. NA
Transport
Unsaturated Zone NA 1 1 unitless One UZ was included in the CSM. NA
Time since material placement TI 0 0 yr Parameter only applicable when used to estimate distribution coefficients. NA
Ground water Concentration W(i) NA NA pCi/L Parameter only applicable when used to estimate distribution coefficients. NA
Solubility Limit SOLUBK0(i) 0 0 Mol/L Parameter only applicable when used to estimate distribution coefficients. NA
Leach Rate RLEACH(i) 0 0 1/yr Parameter only applicable when used to estimate distribution coefficients. NA
Plant/Soil Ratio NA Variable Unchecked NA Parameter only applicable when used to estimate distribution coefficients. NA
Distribution coefficients, Kd (Contaminated Zone/ Unsaturated Zone / Saturated Zone)
Carbon
DCACTC(i) 0 5
cm3/g
Soil Solid/Liquid Partitioning Coefficients, KdS, cm3/g
(Sheppard and Thibault 1990)
Element Sand Loam Clay Organic
Carbon 5 20 1 70
Cesium 280 4,600 1,900 270
Sheppard and Thibault, 1990 DCACTU1(i) 0 5
DCACTS(i) 0 5
Cesium
DCACTC(i) 4,600 280
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 4,600 280
DCACTS(i) 4,600 280
Table B-1. RESRAD ONSITE Input Parameters for the Resident Farmer Scenario
Characterization Report B-4 North Wind Services, LLC
Area 2 SWMU 11 Dugway, Utah February 2020
RESRAD ONSITE INPUT PARAMETER
Parameter Code Default Value Units Justification Reference
Niobium
DCACTC(i) 0 160
cm3/g
Niobium 160 550 900 2,000
Lead 270 16,000 550 22,000
Plutonium 550 1,200 5,100 1,900
Radium 500 36,000 9,100 2,400
Strontium 15 20 110 150
Thorium 3,200 3,300 5,800 89,000
Uranium 35 15 1,600 410

Sheppard and Thibault, 1990 DCACTU1(i) 0 160
DCACTS(i) 0 160
Lead
DCACTC(i) 100 270
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 100 270
DCACTS(i) 100 270
Plutonium
DCACTC(i) 2,000 550
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 2,000 550
DCACTS(i) 2,000 550
Radium
DCACTC(i) 70 500
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 70 500
DCACTS(i) 70 500
Strontium
DCACTC(i) 30 15
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 30 15
DCACTS(i) 30 15
Thorium
DCACTC(i) 60,000 3,200
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 60,000 3,200
DCACTS(i) 60,000 3,200
Uranium
DCACTC(i) 50 35
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 50 35
DCACTS(i) 50 35
MODIFY DATA – Calculation Times
Times for calculation T(t) 1 to 1,000 1 to 1,000 yr Standard calculation times over 1,000-year evaluation period. NA
MODIFY DATA – Contaminated Zone
Contaminated zone area AREA 10,000 1033 (TR-5) 906.7 (TR-6) m2
P2 Physical Parameter. Assumed all waste was exhumed and brought to surface and spread over an area resulting in a depth of 0.15 m. Trench TR-5 waste volume estimate is 194 cubic yards in CABRERA (2016). The model area was conservatively assumed to be a
rectangular soil volume that was46 ft long by 17 ft wide by up to 7 ft deep, which equals 155 m3 (203 yd3). Trench TR-6 waste volume estimate is 165 CY in CABRERA (2016). The model area was conservatively assumed to be a rectangular soil volume that was 40 ft
long by 20 ft wide by up to 6 ft deep, which equals 136 m3 (178 yd3)).
NA
Contaminated zone thickness THICK0 2 0.15 (TR-5)
0.15 (TR-6) m
P2 Physical Parameter. Assumed all waste was spread over 2,023 m2.
TR-5 calculated as 155 m3/1,033 m2 = 0.015 m or 6 inches.
TR-6 calculated as 136 m3/906.7 m2 = 0.015 m or 6 inches.
NA
Length parallel to aquifer LCSPAQ 100 18.1 (TR-5) 17.0 (TR-6) m P2 Physical Parameter. Based on a circular source with a radius of 2. Based on a circular source with an area equal to the contaminated zone area above. NA
Table B-1. RESRAD ONSITE Input Parameters for the Resident Farmer Scenario
Characterization Report B-5 North Wind Services, LLC
Area 2 SWMU 11 Dugway, Utah February 2020
RESRAD ONSITE INPUT PARAMETER
Parameter Code Default Value Units Justification Reference
MODIFY DATA – Cover / Hydrology
Cover depth COVER0 0 0 m P2 Physical Parameter. No cover material was assumed. NA
Density of contaminated zone DENSCS 1.5 1.51 g/cm3 P1 Physical Parameter. Mean Value from NUREG/CR-6697, Attachment C, Table 3.1-1. NA
Contaminated zone erosion rate VCS 0.001 1E-30 m/yr P2 Physical Parameter. No erosion is assumed since SWMU 11 is located in the remote southwest portion of DPG and lies within a small canyon on the east side of Granite
Mountain.
NA
Contaminated zone total porosity TPCS 0.4 0.43 unitless P2 Physical Parameter. Mean value selected for sand in Table 3.2-1 in NUREG/CR-6697. NUREG/CR-6697
Contaminated zone field capacity FCCS 0.2 0.1 unitless P3 Physical Parameter. Value for sand in Table 2.16.1 of the RESRAD Data Collection Handbook (Yu et al. 2015). Yu et al. 2015
Contaminated zone hydraulic conductivity HCCS 10 100 m/yr
P2 Physical Parameter. Value for sand in Table 2.4.1 of the RESRAD Data Collection Handbook (Yu et al. 2015). As noted by Yu et al. 2016, within an anisotropic geological formation, the vertical component of the saturated hydraulic conductivity is usually smaller (by one to two orders of magnitude) than the horizontal component. Therefore, the mean
value was reduced by two orders of magnitude for the vertical hydraulic conductivity.
Yu et al. 2015
Contaminated zone b parameter BCS 5.3 4.05 m2 P2 Physical Parameter. The b parameter was selected for sand from Table 2.5.1 of the RESRAD Data Collection Handbook (Yu et al. 2015). Yu et al. 2015
Humidity in air HUMID 8 NA g/m3 NA. Tritium is not a radionuclide of concern for the site. Humidity input is only required if Tritium is present. NA
Evapotranspiration coefficient EVAPTR 0.5 0.5 unitless P2 Physical Parameter. RESRAD default used. NA
Wind speed WIND 2 2.68 m/sec P2 Physical Parameter. Foster Wheeler 1997
Precipitation PRECIP 1 0.1986 m/yr P2 Physical Parameter. Average annual rainfall (7.82 inches/yr) measured at the Station:(422257) DUGWAY from 1950 to 2006 (https://wrcc.dri.edu/cgi-bin/cliMAIN.pl?utdugw).
Desert Research
Institute Website
Irrigation RI 0.2 0.1125 m/yr P3 Physical Parameter. The value of 0.1125 used in NUREG/CR-6697 was selected.
Irrigation mode IDITCH Overhead Overhead unitless P3 Physical Parameter. Overhead irrigation was selected. NA
Runoff coefficient RUNOFF 0.2 0.4 unitless P2 Physical Parameter. Site-specific runoff coefficient was calculated using the data provided in NUREG/CR-6697, Att. C, Table 4.2-1 assuming flat cultivated land with intermediate combination of clay and loam. NUREG/CR-6697
Watershed area for nearby stream or pond WAREA 1.00 E+06 NA m2 P3 Physical Parameter. Surface water and aquatic food not considered. NA
Accuracy for Water / Soil computations EPS 0.001 0.001 unitless This is a RESRAD model-related parameter for computational convergence and calculation time. NA
MODIFY DATA – Saturated Zone
Saturated zone density DENSAQ 1.5 1.51 g/cm3 P1 Physical Parameter. Mean Value from NUREG/CR-6697, Attachment C, Table 3.1-1. NA
Saturated zone total porosity TPSZ 0.4 0.43 unitless P2 Physical Parameter. Mean PDF value selected for sand in Table 3.2-1 in NUREG/CR-6697. NUREG/CR-6697
Saturated zone effective porosity EPSZ 0.2 0.383 unitless P1 Physical Parameter. Mean of PDF for sand provided in NUREG/CR-6697, Attachment C, Table 3.3-1, was used. NUREG/CR-6697
Saturated zone field capacity FCSZ 0.2 0.1 unitless P3 Physical Parameter. Value for sand in Table 2.16.1 of the RESRAD Data Collection Handbook (Yu et al. 2015). Yu et al. 2015
Table B-1. RESRAD ONSITE Input Parameters for the Resident Farmer Scenario
Characterization Report B-6 North Wind Services, LLC
Area 2 SWMU 11 Dugway, Utah February 2020
RESRAD ONSITE INPUT PARAMETER
Parameter Code Default Value Units Justification Reference
Saturated zone hydraulic conductivity HCSZ 100 5,550 m/yr P2 Physical Parameter. Value for sand in Table 2.4.2 of the RESRAD Data Collection Handbook (Yu et al. 2015). Yu et al. 2015
Saturated zone hydraulic gradient HGWT 0.02 0.02 unitless P2 Physical Parameter. RESRAD default used. NA
Saturated zone b parameter BSZ 5.3 4.05 m2 P2 Physical Parameter. The b parameter was selected for sand from Table 2.5.1 of the RESRAD Data Collection Handbook (Yu et al. 2015). Yu et al. 2015
Water table drop rate VWT 0.001 0 m/yr P3 Physical Parameter. No water table drop due to pumping was assumed. NA
Well pump intake depth (m below water table) DWIBWT 10 10 m P2 Physical Parameter. RESRAD default used. NA
Model: Non-dispersion (ND) or Mass-Balance (MB) MODEL ND ND unitless The area of contamination is approximately 1,000 m2; therefore, the non-dispersion model
was assumed. NA
Well pumping rate UW 250 250 m3/yr P2 Physical Parameter. RESRAD default used. NA
MODIFY DATA – Unsaturated
Number of unsaturated strata NS 1 1 unitless Based upon site-specific hydrogeology one UZ was modeled. NA
Unsaturated zone thickness H(1) 4 18.6 m P1 Physical Parameter. Depth to groundwater at SWMU-11 is approximately 61 ft bgs based on water-level measurements from MW01. Parsons 2009
Unsaturated zone density DENSUZ(1) 1.5 1.51 g/cm3 P1 Physical Parameter. Mean Value from NUREG/CR-6697, Attachment C, Table 3.1-1. NA
Unsaturated zone total porosity TPUZ(1) 0.4 0.43 unitless P2 Physical Parameter. Mean value selected for sand in Table 3.2-1 in NUREG/CR-6697. NUREG/CR-6697
Unsaturated zone effective porosity EPUZ(1) 0.2 0.383 unitless P1 Physical Parameter. Mean of PDF for sand provided in NUREG/CR-6697, Attachment C, Table 3.3-1, was used. NUREG/CR-6697
Unsaturated zone field capacity FCUZ(1) 0.2 0.1 unitless P3 Physical Parameter. Value for sand in Table 2.16.1 of the RESRAD Data Collection
Handbook (Yu et al. 2015). Yu et al. 2015
Unsaturated zone hydraulic conductivity HCUZ(1) 10 100 m/yr
P2 Physical Parameter. Value for sand in Table 2.4.1 of the RESRAD Data Collection
Handbook (Yu et al. 2015). As noted by Yu et al. 2016, within an anisotropic geological formation, the vertical component of the saturated hydraulic conductivity is usually smaller (by one to two orders of magnitude) than the horizontal component. Therefore, the mean
value was reduced by two orders of magnitude for the vertical hydraulic conductivity.
Yu et al. 2015
Unsaturated zone b parameter BUZ(1) 5.3 4.05 m2 P2 Physical Parameter. The b parameter was selected for sand from Table 2.5.1 of the
RESRAD Data Collection Handbook (Yu et al. 2015). Yu et al. 2015
MODIFY DATA – Occupancy
Inhalation rate INHALR 8,400 8,400 m3/yr Metabolic Parameter. The mean of NUREG-5512, Vol. 3 PDF used. NUREG-5512
Mass loading for inhalation MLINH 0.0001 0.0001 g/m3 P2 Physical Parameter. RESRAD Default. NA
Exposure duration ED 30 30 yr The standard time that the critical receptor is expected to reside on site. NA
Indoor dust filtration factor SHF3 0.4 0.55 unitless P2 Physical Parameter. The median of the NUREG-6697 PDF used. NUREG-6697
Fraction of time spent indoors FIND 0.5 0.66 unitless Behavioral Parameter. Mean of NUREG-5512 Vol. 3 PDF used. NUREG-5512
Fraction of time spent outdoors (on-site) FOTD 0.25 0.12 unitless Behavioral Parameter. Mean of NUREG-5512 Vol. 3 PDF used. NUREG-5512
Shape of the contaminated zone: Circular; Non-
Circular FS Circular Circular unitless P3 Physical Parameter. The modeled shape primarily affects the external pathway. NA
External gamma shielding factor SHF1 0.7 0.21 unitless P2 Physical Parameter. A SF of 0.21 was selected. This is consistent with NUREG/CR-6697, which recommends an SF of 0.21 for frame homes built on a slab or with a full basement. NUREG-6697
Table B-1. RESRAD ONSITE Input Parameters for the Resident Farmer Scenario
Characterization Report B-7 North Wind Services, LLC
Area 2 SWMU 11 Dugway, Utah February 2020
RESRAD ONSITE INPUT PARAMETER
Parameter Code Default Value Units Justification Reference
MODIFY DATA – Ingestion: Dietary
Fruits, vegetables and grain consumption DIET(1) 160 112 kg/yr Behavioral Parameters. Mean of NUREG - 5512 PDFs used. NUREG - 5512
Leafy vegetable consumption DIET(2) 14 21 kg/yr Behavioral Parameters. Mean of NUREG - 5512 PDFs used. NUREG - 5512
Milk consumption DIET(3) 92 233 L/yr Behavioral Parameters. Mean of NUREG - 5512 PDFs used. NUREG - 5512
Meat and poultry consumption DIET(4) 63 65 kg/yr Behavioral Parameters. Mean of NUREG - 5512 PDFs used. NUREG - 5512
Soil ingestion rate SOIL 36.5 18.2 g/yr Behavioral Parameter. Mean of NUREG-5512 Vol. 3 PDF used. NUREG - 5512
Drinking water intake DWI 510 460 L/yr Behavioral Parameter. Mean of NUREG-5512 Vol. 3 PDF used. NUREG-5512
Contamination fraction of drinking water FDW 1 1 unitless All drinking water assumed to be contaminated. NA
Contamination fraction of household water FHHW 1 NA unitless NA. Radon pathway not active. NA
Contamination fraction of livestock water FLW 1 1 unitless All livestock water assumed to be contaminated. NA
Contamination fraction of irrigation water FDW 1 1 unitless All irrigation water assumed to be contaminated. NA
Contamination fraction of plant food FPLANT -1 -1 unitless Value of -1 automatically adjusts percentage of contaminated food ingested based on the contaminated site area. NA
Contamination fraction of Meat FMEAT -1 -1 unitless Value of -1 automatically adjusts percentage of contaminated food ingested based on the contaminated site area. NA
Contamination fraction of Milk FMILK -1 -1 unitless Value of -1 automatically adjusts percentage of contaminated food ingested based on the contaminated site area. NA
MODIFY DATA – Ingestion: Non-Dietary
Livestock fodder intake for Meat LFI5 68 68 kg/d P3 Physical Parameters. RESRAD default used. NA
Livestock fodder intake for Milk LFI6 55 55 kg/d P3 Physical Parameters. RESRAD default used. NA
Livestock water intake for Meat LWI5 50 50 L/d P3 Physical Parameters. RESRAD default used. NA
Livestock water intake for Milk LWI6 160 160 L/d P3 Physical Parameters. RESRAD default used. NA
Livestock soil intake LSI 0.5 05 kg/d P3 Physical Parameters. RESRAD default used. NA
Mass loading for foliar deposition MLFD 0.0001 0.0001 g/m3 P3 Physical Parameter. RESRAD default. NA
Depth of soil mixing layer DM 0.15 0.15 m P2 Physical Parameter. No site-specific data. The most likely value from the PDF recommended in NUREG/CR- 6697 is 0.15 m. See Section 5.3.4.4. NUREG/CR- 6697
Depth of roots DROOT 0.9 0.9 m P1 Physical Parameter. NUREG/CR-6697 states that the root depth for plants that provide
the most nutrients typically extend less than 1 meter. NUREG/CR- 6697
Drinking water fraction from ground water FGWDW 1 1 unitless All drinking water assumed to be derived from site ground water. NA
Household water fraction from ground water FGWHH 1 NA unitless NA. Radon pathway is not selected; hence, this parameter is not applicable. NA
Livestock fraction from ground water FGWLW 1 1 unitless All livestock water assumed to be obtained from site ground water. NA
Irrigation fraction from ground water FGWIR 1 1 unitless All irrigation water assumed to be obtained from site ground water. NA
Plant Factors
Wet weight crop yield for non-leafy vegetables YV(1) 0.7 0.56 kg/m2 P2 Physical Parameter. No site-specific data. The mean of the NUREG/CR-6697 PDF used. NUREG/CR- 6697
Wet weight crop yield for leafy vegetables YV(2) 1.5 1.5 kg/m2 P3 Physical Parameter. RESRAD default used. NA
Wet weight crop yield for fodder YV(3) 1.1 1.1 kg/m2 P3 Physical Parameter. RESRAD default used. NA
Table B-1. RESRAD ONSITE Input Parameters for the Resident Farmer Scenario
Characterization Report B-8 North Wind Services, LLC
Area 2 SWMU 11 Dugway, Utah February 2020
RESRAD ONSITE INPUT PARAMETER
Parameter Code Default Value Units Justification Reference
Growing season for leafy vegetables TE(2) 0.25 0.25 yr P3 Physical Parameter. RESRAD default used. NA
Growing season for non-leafy vegetables TE(1) 0.17 0.17 yr P3 Physical Parameter. RESRAD default used. NA
Growing season for fodder TE(3) 0.08 0.08 yr P3 Physical Parameter. RESRAD default used. NA
Translocation factor for non-leafy vegetables TIV(1) 0.1 0.1 unitless P3 Physical Parameter. The RESRAD default value was used. NA
Translocation factor for leafy vegetables TIV(2) 1 1 unitless P3 Physical Parameters. A value of 1 was assigned assuming the entire plant is consumed. NA
Weathering removal constant for vegetation WLAM 20 33 unitless P2 Physical Parameter. The median of NUREG/CR-6697 PDF used. NUREG/CR- 6697
Wet foliar interception fraction for non-leafy vegetables RWET(1) 0.25 0.25 unitless P3 Physical Parameter. RESRAD default value used. NA
Wet foliar interception fraction for leafy vegetables RWET(2) 0.25 0.6 unitless P2 Physical Parameter. Median of NUREG/CR-6697 PDF used. NUREG/CR- 6697
Wet foliar interception fraction for fodder RWET(3) 0.25 0.25 unitless P3 Physical Parameters. RESRAD default value used. NA
Dry foliar interception fraction for non-leafy vegetables RDRY(1) 0.25 0.25 unitless P3 Physical Parameters. RESRAD default value used. NA
Dry foliar interception fraction for leafy vegetables RDRY(2) 0.25 0.25 unitless P3 Physical Parameters. RESRAD default value used. NA
Dry foliar interception fraction for fodder RDRY(3) 0.25 0.25 unitless P3 Physical Parameters. RESRAD default value used. NA
MODIFY DATA – Storage Time
Storage time: fruits, non-leafy vegetables, and grain STOR_T(1) 14 14 D P3 Physical Parameters. RESRAD default values used. NA
Storage time: leafy vegetables STOR_T(2) 1 1 D P3 Physical Parameters. RESRAD default values used. NA
Storage time: milk STOR_T(3) 1 1 D P3 Physical Parameters. RESRAD default values used. NA
Storage time: meat and poultry STOR_T(4) 20 20 D P3 Physical Parameters. RESRAD default values used. NA
Storage time: well water STOR_T(7) 1 1 D P3 Physical Parameters. RESRAD default values used. NA
Storage time: livestock fodder STOR_T(9) 45 45 D P3 Physical Parameters. RESRAD default values used. NA
960
Table B-2. RESRAD ONSITE Input Parameters for the Industrial Worker Scenario
Characterization Report B-9 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
RESRAD ONSITE INPUT PARAMETER
Parameter Code Default Value Units Justification Reference
CHANGE TITLES
Internal dose factor library NA NA FGR-11 NA Federal Guidance Report 11 Dose Factors required by NRC. NUREG-1757
External dose factor library NA NA FGR-12 NA Federal Guidance Report 12 Dose Factors required by NRC. NUREG-1757
Cut-off ½ life NA 180 180 days Cut-off for daughter products (progeny) for in-growth calculation. NA
SET PATHWAY
External gamma NA Active Active unitless Site Conceptual Model, Industrial Worker. NA
Inhalation (w/o radon) NA Active Active unitless Site Conceptual Model, Industrial Worker. NA
Plant ingestion NA Active Inactive unitless Site Conceptual Model, Industrial Worker. NA
Meat ingestion NA Active Inactive unitless Site Conceptual Model, Industrial Worker. NA
Milk ingestion NA Active Inactive unitless Site Conceptual Model, Industrial Worker. NA
Aquatic foods NA Active Inactive unitless Site Conceptual Model, Industrial Worker. NA
Drinking water NA Active Active unitless Site Conceptual Model, Industrial Worker. NA
Soil ingestion NA Active Active unitless Site Conceptual Model, Industrial Worker. NA
Radon NA Active Inactive unitless NUREG-1757, Vol. 2, Section J.4 states that the Radon pathway should be turned off. NUREG-1757
MODIFY DATA – Soil Concentrations
Activity units NA pCi pCi NA Standard reporting units. NA
Dose units NA mrem mrem NA Standard reporting units. NA
Basic radiation dose limit NA NA 100 mrem/yr NRC TEDE limit for restricted site release. 10 CFR 20.1403
Nuclide concentration S(i) NA 1 pCi/g A unit concentration was used as the input value for each COC. NA
Transport
Unsaturated Zone NA 1 1 unitless One UZ was included in the CSM. NA
Time since material placement TI 0 0 yr Parameter only applicable when used to estimate distribution coefficients. NA
Ground water Concentration W(i) NA NA pCi/L Parameter only applicable when used to estimate distribution coefficients. NA
Solubility Limit SOLUBK0(i) 0 0 Mol/L Parameter only applicable when used to estimate distribution coefficients. NA
Leach Rate RLEACH(i) 0 0 1/yr Parameter only applicable when used to estimate distribution coefficients. NA
Plant/Soil Ratio NA Variable Unchecked NA Parameter only applicable when used to estimate distribution coefficients. NA
Distribution coefficients, Kd (Contaminated Zone/ Unsaturated Zone / Saturated Zone)
Carbon
DCACTC(i) 0 5
cm3/g
Soil Solid/Liquid Partitioning Coefficients, KdS, cm3/g
(Sheppard and Thibault 1990)
Element Sand Loam Clay Organic
Carbon 5 20 1 70
Cesium 280 4,600 1,900 270
Sheppard and Thibault, 1990 DCACTU1(i) 0 5
DCACTS(i) 0 5
Cesium
DCACTC(i) 4,600 280
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 4,600 280
DCACTS(i) 4,600 280
Table B-2. RESRAD ONSITE Input Parameters for the Industrial Worker Scenario
Characterization Report B-10 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
RESRAD ONSITE INPUT PARAMETER
Parameter Code Default Value Units Justification Reference
Niobium 160 550 900 2,000
Lead 270 16,000 550 22,000
Plutonium 550 1,200 5,100 1,900
Radium 500 36,000 9,100 2,400
Strontium 15 20 110 150
Thorium 3,200 3,300 5,800 89,000
Uranium 35 15 1,600 410

Niobium
DCACTC(i) 0 160
cm3/g

Sheppard and Thibault, 1990 DCACTU1(i) 0 160
DCACTS(i) 0 160
Lead
DCACTC(i) 100 270
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 100 270
DCACTS(i) 100 270
Plutonium
DCACTC(i) 2,000 550
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 2,000 550
DCACTS(i) 2,000 550
Radium
DCACTC(i) 70 500
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 70 500
DCACTS(i) 70 500
Strontium
DCACTC(i) 30 15
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 30 15
DCACTS(i) 30 15
Thorium
DCACTC(i) 60,000 3,200
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 60,000 3,200
DCACTS(i) 60,000 3,200
Uranium
DCACTC(i) 50 35
cm3/g Sheppard and Thibault, 1990 DCACTU1(i) 50 35
DCACTS(i) 50 35
MODIFY DATA – Calculation Times
Times for calculation T(t) 1 to 1,000 1 to 1,000 yr Standard calculation times over 1,000-year evaluation period. NA
MODIFY DATA – Contaminated Zone
Contaminated zone area AREA 10,000 1,033 (TR-5)
906.7 (TR-6) m2
P2 Physical Parameter. Assumed all waste was exhumed and brought to surface and spread over an area resulting in a depth of 0.15 m. Trench TR-5 waste volume estimate is 194 cubic yards in CABRERA (2016). The model area was conservatively assumed to be a rectangular soil volume that was46 ft long by 17 ft wide by up to 7 ft deep, which equals 155 m3 (203 yd3). Trench TR-6 waste volume estimate is 165 CY in CABRERA (2016). The model area was conservatively assumed to be a rectangular soil volume that was 40 ft long by 20 ft wide by up to 6 ft deep, which equals 136 m3 (178 yd3)).
NA
Table B-2. RESRAD ONSITE Input Parameters for the Industrial Worker Scenario
Characterization Report B-11 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
RESRAD ONSITE INPUT PARAMETER
Parameter Code Default Value Units Justification Reference
Contaminated zone thickness THICK0 2 0.15 (TR-5) 0.15 (TR-6) m
P2 Physical Parameter. Assumed all waste was spread over 2,023 m2.
TR-5 calculated as 155 m3/1,033 m2 = 0.015 m or 6 inches.
TR-6 calculated as 136 m3/906.7 m2 = 0.015 m or 6 inches.
NA
Length parallel to aquifer LCSPAQ 100 18.1 (TR-5)
17.0 (TR-6) m P2 Physical Parameter. Based on a circular source with a radius of 2. Based on a circular source with an area equal to the contaminated zone area above. NA
MODIFY DATA – Cover / Hydrology
Cover depth COVER0 0 0 m P2 Physical Parameter. No cover material was assumed. NA
Density of contaminated zone DENSCS 1.5 1.51 g/cm3 P1 Physical Parameter. Mean Value from NUREG/CR-6697, Attachment C, Table 3.1-1. NA
Contaminated zone erosion rate VCS 0.001 1E-30 m/yr P2 Physical Parameter. No erosion is assumed since SWMU 11 is located in the remote southwest
portion of DPG and lies within a small canyon on the east side of Granite Mountain. NA
Contaminated zone total porosity TPCS 0.4 0.43 unitless P2 Physical Parameter. Mean value selected for sand in Table 3.2-1 in NUREG/CR-6697. NUREG/CR-6697
Contaminated zone field capacity FCCS 0.2 0.1 unitless P3 Physical Parameter. Value for sand in Table 2.16.1 of the RESRAD Data Collection Handbook (Yu et
al. 2015). Yu et al. 2015
Contaminated zone hydraulic
conductivity HCCS 10 100 m/yr
P2 Physical Parameter. Value for sand in Table 2.4.1 of the RESRAD Data Collection Handbook (Yu et
al. 2015). As noted by Yu et al. 2016, within an anisotropic geological formation, the vertical component of the saturated hydraulic conductivity is usually smaller (by one to two orders of magnitude) than the horizontal component. Therefore, the mean value was reduced by two orders of
magnitude for the vertical hydraulic conductivity.
Yu et al. 2015
Contaminated zone b parameter BCS 5.3 4.05 m2 P2 Physical Parameter. The b parameter was selected for sand from Table 2.5.1 of the RESRAD Data
Collection Handbook (Yu et al. 2015). Yu et al. 2015
Humidity in air HUMID 8 NA g/m3 NA. Tritium is not a radionuclide of concern for the site. Humidity input is only required if Tritium is present. NA
Evapotranspiration coefficient EVAPTR 0.5 0.5 unitless P2 Physical Parameter. RESRAD default used. NA
Wind speed WIND 2 2.68 m/sec P2 Physical Parameter. Foster Wheeler 1997
Precipitation PRECIP 1 0.1986 m/yr P2 Physical Parameter. Average annual rainfall (7.82 inches/yr) measured at the Station:(422257) DUGWAY from 1950 to 2006 (https://wrcc.dri.edu/cgi-bin/cliMAIN.pl?utdugw). Desert Research Institute Website
Irrigation RI 0.2 0 m/yr P3 Physical Parameter. No irrigation assumed.
Runoff coefficient RUNOFF 0.2 0.4 unitless P2 Physical Parameter. Site-specific runoff coefficient was calculated using the data provided in NUREG/CR-6697, Att. C, Table 4.2-1 assuming flat cultivated land with intermediate combination of clay and loam. NUREG/CR-6697
Watershed area for nearby
stream or pond WAREA 1.00 E+06 NA m2 P3 Physical Parameter. Surface water and aquatic food not considered. NA
Accuracy for Water / Soil computations EPS 0.001 0.001 unitless This is a RESRAD model-related parameter for computational convergence and calculation time. NA
Table B-2. RESRAD ONSITE Input Parameters for the Industrial Worker Scenario
Characterization Report B-12 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
RESRAD ONSITE INPUT PARAMETER
Parameter Code Default Value Units Justification Reference
MODIFY DATA – Saturated Zone
Saturated zone density DENSAQ 1.5 1.51 g/cm3 P1 Physical Parameter. Mean Value from NUREG/CR-6697, Attachment C, Table 3.1-1. NA
Saturated zone total porosity TPSZ 0.4 0.43 unitless P2 Physical Parameter. Mean PDF value selected for sand in Table 3.2-1 in NUREG/CR-6697. NUREG/CR-6697
Saturated zone effective porosity EPSZ 0.2 0.383 unitless P1 Physical Parameter. Mean of PDF for sand provided in NUREG/CR-6697, Attachment C, Table 3.3-1, was used. NUREG/CR-6697
Saturated zone field capacity FCSZ 0.2 0.1 unitless P3 Physical Parameter. Value for sand in Table 2.16.1 of the RESRAD Data Collection Handbook (Yu et al. 2015). Yu et al. 2015
Saturated zone hydraulic conductivity HCSZ 100 5,550 m/yr P2 Physical Parameter. Value for sand in Table 2.4.2 of the RESRAD Data Collection Handbook (Yu et al. 2015). Yu et al. 2015
Saturated zone hydraulic gradient HGWT 0.02 0.02 unitless P2 Physical Parameter. RESRAD default used. NA
Saturated zone b parameter BSZ 5.3 4.05 m2 P2 Physical Parameter. The b parameter was selected for sand from Table 2.5.1 of the RESRAD Data
Collection Handbook (Yu et al. 2015). Yu et al. 2015
Water table drop rate VWT 0.001 0 m/yr P3 Physical Parameter. No water table drop due to pumping was assumed. NA
Well pump intake depth (m below water table) DWIBWT 10 10 m P2 Physical Parameter. RESRAD default used. NA
Model: Non-dispersion (ND) or Mass-Balance (MB) MODEL ND ND unitless The area of contamination is approximately 1,000 m2; therefore, the non-dispersion model was assumed. NA
Well pumping rate UW 250 250 m3/yr P2 Physical Parameter. RESRAD default used. NA
MODIFY DATA – Unsaturated
Number of unsaturated strata NS 1 1 unitless Based upon site-specific hydrogeology one UZ was modeled. NA
Unsaturated zone thickness H(1) 4 18.6 m P1 Physical Parameter. Depth to groundwater at SWMU-11 is approximately 61 ft bgs based on water-
level measurements from MW01. Parsons 2009
Unsaturated zone density DENSUZ(1) 1.5 1.51 g/cm3 P1 Physical Parameter. Mean Value from NUREG/CR-6697, Attachment C, Table 3.1-1. NA
Unsaturated zone total porosity TPUZ(1) 0.4 0.43 unitless P2 Physical Parameter. Mean value selected for sand in Table 3.2-1 in NUREG/CR-6697. NUREG/CR-6697
Unsaturated zone effective
porosity EPUZ(1) 0.2 0.383 unitless P1 Physical Parameter. Mean of PDF for sand provided in NUREG/CR-6697, Attachment C, Table
3.3-1, was used. NUREG/CR-6697
Unsaturated zone field capacity FCUZ(1) 0.2 0.1 unitless P3 Physical Parameter. Value for sand in Table 2.16.1 of the RESRAD Data Collection Handbook (Yu et al. 2015). Yu et al. 2015
Unsaturated zone hydraulic conductivity HCUZ(1) 10 100 m/yr
P2 Physical Parameter. Value for sand in Table 2.4.1 of the RESRAD Data Collection Handbook (Yu et al. 2015). As noted by Yu et al. 2016, within an anisotropic geological formation, the vertical component of the saturated hydraulic conductivity is usually smaller (by one to two orders of
magnitude) than the horizontal component. Therefore, the mean value was reduced by two orders of magnitude for the vertical hydraulic conductivity.
Yu et al. 2015
Unsaturated zone b parameter BUZ(1) 5.3 4.05 m2 P2 Physical Parameter. The b parameter was selected for sand from Table 2.5.1 of the RESRAD Data Collection Handbook (Yu et al. 2015). Yu et al. 2015
Table B-2. RESRAD ONSITE Input Parameters for the Industrial Worker Scenario
Characterization Report B-13 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
RESRAD ONSITE INPUT PARAMETER
Parameter Code Default Value Units Justification Reference
MODIFY DATA – Occupancy
Inhalation rate INHALR 8,400 8,400 m3/yr Metabolic Parameter. The mean of NUREG-5512, Vol. 3 PDF used. NUREG-5512
Mass loading for inhalation MLINH 0.0001 0.0001 g/m3 P2 Physical Parameter. RESRAD default. NA
Exposure duration ED 30 30 yr The standard time that the critical receptor is expected to reside on site. NA
Indoor dust filtration factor SHF3 0.4 0.55 unitless P2 Physical Parameter. The median of the NUREG-6697 PDF used. NUREG-6697
Fraction of time spent indoors FIND 0.5 0.028 unitless Behavioral Parameter. Industrial worker assumes 8 hr/day for 250 days/yr, of which 1 hr/day is spent indoors. NA
Fraction of time spent outdoors (on-site) FOTD 0.25 0.2 unitless Behavioral Parameter. Industrial worker assumes 8 hr/day for 250 days/yr, of which 7 hr/day is spent outdoors. NA
Shape of the contaminated zone: Circular; Non-Circular FS Circular Circular unitless P3 Physical Parameter. The modeled shape primarily affects the external pathway. NA
External gamma shielding factor SHF1 0.7 0.21 unitless P2 Physical Parameter. A SF of 0.21 was selected. This is consistent with NUREG/CR-6697, which recommends an SF of 0.21 for frame homes built on a slab or with a full basement. NUREG-6697
MODIFY DATA – Ingestion: Dietary
Soil ingestion rate SOIL 36.5 18.25 g/yr Behavioral Parameter (EPA 1991). 50 mg/day. EPA 1991
Drinking water intake DWI 510 460 L/yr Behavioral Parameter. Mean of NUREG-5512 Vol. 3 PDF used. NUREG-5512
Contamination fraction of drinking
water FDW 1 1 unitless All drinking water assumed to be contaminated. NA
Contamination fraction of
household water FHHW 1 NA unitless NA. Radon pathway not active. NA
MODIFY DATA – Ingestion: Non-Dietary
Drinking water fraction from
ground water FGWDW 1 1 unitless All drinking water assumed to be derived from site ground water. NA
Household water fraction from ground water FGWHH 1 NA unitless NA. Radon pathway is not selected; hence, this parameter is not applicable. NA

Characterization Report B-14 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
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Characterization Report B-15 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Appendix B – References 1
Cabrera, 2016, Final Report: Area 2 Solid Waste Management Unit (SWMU) 11 Trenches TR-5 and 2
TR-6, Dugway Proving Ground, Dugway, Utah. September 2016. 3
Code of Federal Regulations, Title 10, Part 20.1402, “Standards for Protection Against 4
Radiation−Radiological Criteria for Unrestricted Use.” 5
Code of Federal Regulations, Title 10, Part 20.1403, “Standards for Protection Against Radiation− 6 Criteria for License Termination Under Restricted Conditions.” 7
Desert Research Institute website: https://wrcc.dri.edu/cgi-bin/cliMAIN.pl?utdugw. 8
EPA 1991. Human Health Evaluation Manual, Supplemental Guidance: “Standard Default Exposure 9 Factors,” OSWER Directive 9285.6-03, Washington, D.C., March. 10
Federal Guidance Report No. 11: Limiting Values of Radionuclide Intake and Air Concentration and 11 Dose Conversion Factors for Inhalation, Submersion, and Ingestion, EPA-520/1-88-020, 12 U.S. Environmental Protection Agency, September 1988. 13
Federal Guidance Report No. 12: External Exposure to Radionuclides in Air, Water, and Soil, EPA-402-14 R-93-081, U.S. Environmental Protection Agency, September 1993. 15
Foster Wheeler, 1997, Dugway Proving Ground Closure Plan Module 2: SWMUs 20, 164, 166, and 170, 16 Foster Wheeler Environmental Company, July 1997. 17
Parsons, 2009, Final Phase II RCRA Facility Investigation: SWMU 11 Addendum, Dugway Proving 18 Ground, Dugway, UT, August 2009. 19
Sheppard, M.I., and D.H. Thibault, 1990, “Default Soil Solid/Liquid Partition Coefficients, KdS, for Four 20 Major Soil Types: A Compendium,” Health Physics 59(4):471-82, October 1990. 21
U.S. Nuclear Regulatory Commission, NUREG-1757, “Consolidated Decommissioning Guidance, 22 Characterization, Survey, and Determination of Radiological Criteria,” Volume 2, Revision 1, 23 September 2006. 24
U.S. Nuclear Regulatory Commission, NUREG/CR-6697, ANL/EAD/TM-98, “Development of 25 Probabilistic RESRAD 6.0 and RESRAD-BUILD 3.0 Computer Codes,” November 2000. 26
U.S. Nuclear Regulatory Commission, NUREG/CR-5512, SAND99-2148, Volume 3, “Residual 27 Radioactive Contamination from Decommissioning - Parameter Analysis,” Draft, October 28 1999. 29
Yu, C., C. Loureiro, J.-J. Cheng, L.G. Jones, Y.Y. Wang, Y.P. Chia, and E. Faillace. Data Collection 30 Handbook to Support Modeling Impacts of Radioactive Material in Soil, ANL/EVS/TM-31 14/4, Argonne National Laboratory, September 2015. 32

Characterization Report B-16 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
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Characterization Report C-1 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Appendix C 34
DCGL Sensitivity and Uncertainty Analysis35

Characterization Report C-2 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
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Characterization Report C-3 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
C.1 INTRODUCTION Sensitivity and uncertainty analyses were conducted on the RESRAD models for the Resident Farmer and
Industrial Worker scenarios. The analyses were focused on Ra-226 at TR-5. C.2 SENSITIVITY ANALYSIS PARAMETERS

A parameter sensitivity analysis was conducted for the Resident Farmer and Industrial Worker scenarios for Ra-226 at TR-5. Ra-226 was chosen for the sensitivity and uncertainty analysis since it is widely distributed throughout TR-5. Similar parameter sensitivities and uncertainties would be expected for the
other COCs for which DCGLs were developed. The parameters considered in the sensitivity analyses were based on those provided in NUREG/CR-6697 and are provided in Tables C-1 and C-2 for the Resident Farmer and Industrial Worker scenarios, respectively.
Table C-1. Resident farmer scenario sensitivity parameters and ranges considered.
Parameter Description Code Sensitivity Range Factora
Sorption Coefficient (Kd) of Ra-226 in contaminated zone DCACTC 10
Sorption Coefficient (Kd) of Ra-226 in unsaturated zone 1 DCACTU 10
Sorption Coefficient (Kd) of Ra-226 in saturated zone DCACTS 10
Density of contaminated zone DENSCZ 1.5
Density of unsaturated zone 1 DENSUZ(1) 1.5
Density of saturated zone DENSAQ 1.5
Total porosity contaminated zone TPCZ 2
Total porosity of unsaturated zone 1 TPUZ(1) 2
Total porosity of saturated zone TPSZ 2
Effective porosity of unsaturated zone 1 EPUZ(1) 2
Saturated zone effective porosity EPSZ 2
Contaminated zone hydraulic conductivity HCCZ 10
Hydraulic conductivity of unsaturated zone 1 HCUZ(1) 10
Saturated zone hydraulic conductivity HCSZ 2
Contaminated zone b parameter BCZ 2
b parameter of unsaturated zone 1 BUZ(1) 2
Saturated zone hydraulic gradient HGWT 2
Runoff coefficient RUNOFF 2
Well pumping rate UW 2
Inhalation rate INHALR 2
Mass loading for inhalation MLINH 2
Indoor dust filtration factor SHF3 1.5
External gamma shielding factor SHF1 2
Table C-1. (continued).
Characterization Report C-4 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Parameter Description Code Sensitivity Range Factora
Fruit, vegetable, and grain consumptionb DIET(1) 2
Milk consumptionb DIET(3) 1.5
Soil ingestion SOIL 2
Drinking water intake DWI 3
Depth of soil mixing layer DM 2
Depth of rootsb DROOT 2
Wet weight crop yield of fruit, grain and non-leafy vegetablesb YV(1) 1.5
Weathering removal constant of all vegetationb WLAM 1.2
Indoor time fractionb FIND 1.5
Wind speed WIND 5
Evapotranspiration coefficient EVAPTR 2
a. The parameter base value is multiplied by factor to obtain the maximum value and divided by the factor to
obtain the minimum value.

Table C-2. Industrial worker scenario sensitivity parameters and ranges considered.
Parameter Description Code Sensitivity Range Factora
Sorption Coefficient (Kd) of Ra-226 in contaminated zone DCACTC 10
Sorption Coefficient (Kd) of Ra-226 in unsaturated zone 1 DCACTU 10
Sorption Coefficient (Kd) of Ra-226 in saturated zone DCACTS 10
Density of contaminated zone DENSCZ 1.5
Density of unsaturated zone 1 DENSUZ(1) 1.5
Density of saturated zone DENSAQ 1.5
Total porosity contaminated zone TPCZ 2
Total porosity of unsaturated zone 1 TPUZ(1) 2
Total porosity of saturated zone TPSZ 2
Effective porosity of unsaturated zone 1 EPUZ(1) 2
Saturated zone effective porosity EPSZ 2
Contaminated zone hydraulic conductivity HCCZ 10
Hydraulic conductivity of unsaturated zone 1 HCUZ(1) 10
Saturated zone hydraulic conductivity HCSZ 2
Contaminated zone b parameter BCZ 2
b parameter of unsaturated zone 1 BUZ(1) 2
Saturated zone hydraulic gradient HGWT 2
Table C-2. (continued).
Characterization Report C-5 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Parameter Description Code Sensitivity Range Factora
Runoff coefficient RUNOFF 2
Well pumping rate UW 2
Inhalation rate INHALR 2
Mass loading for inhalation MLINH 2
External gamma shielding factor SHF1 2
Soil ingestion SOIL 2
Drinking water intake DWI 3
Depth of soil mixing layer DM 2
Wind speed WIND 5
Evapotranspiration coefficient EVAPTR 2
a. The parameter base value is multiplied by factor to obtain the maximum value and divided by the factor to
obtain the minimum value.

C.2.1 Sensitivity Analysis Results – Resident Farmer Scenario
The results of the sensitivity analysis for the Resident Farmer scenario are provided in Figures C-1 through C-36. The doses based on the upper, middle and lower parameter values are provided in each figure, however, in several cases the doses are the same (i.e., parameter is not sensitive). The following
parameters were found to have the highest sensitivities in the Resident Farmer scenario: 1) Sorption coefficient (Kd) of the contaminated zone
2) Density of the contaminated zone
3) Runoff coefficient
4) External gamma shielding factor
5) Fruit, vegetable and grain consumption rate
6) Soil ingestion
7) Depth of soil mixing layer
8) Depth of roots
9) Indoor time fraction
10) Evapotranspiration coefficient.

Characterization Report C-6 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-1. Sorption coefficient (Kd) in the contaminated zone.

Characterization Report C-7 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-2. Sorption coefficient (Kd) in the unsaturated zone.

Characterization Report C-8 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-3. Sorption coefficient (Kd) in the saturated zone.

Characterization Report C-9 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-4. Density of the contaminated zone.

Characterization Report C-10 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-5. Density of the unsaturated zone.

Characterization Report C-11 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-6. Density of the saturated zone.

Characterization Report C-12 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-7. Total porosity of the contaminated zone.

Characterization Report C-13 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-8. Total porosity of the unsaturated zone.

Characterization Report C-14 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-9. Total porosity of the saturated zone.

Characterization Report C-15 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-10. Effective porosity of the unsaturated zone.

Characterization Report C-16 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-11. Effective porosity of the saturated zone.

Characterization Report C-17 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-12. Contaminated zone hydraulic conductivity.

Characterization Report C-18 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-13. Unsaturated zone hydraulic conductivity.

Characterization Report C-19 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-14. Saturated zone hydraulic conductivity.

Characterization Report C-20 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-15. Contaminated zone b parameter.

Characterization Report C-21 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-16. Unsaturated zone b parameter.

Characterization Report C-22 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-17. Saturated zone hydraulic gradient.

Characterization Report C-23 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-18. Runoff Coefficient.

Characterization Report C-24 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-19. Well pumping rate.

Characterization Report C-25 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-20. Inhalation rate.

Characterization Report C-26 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-21. Mass loading for inhalation.

Characterization Report C-27 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-22. Indoor dust filtration factor.

Characterization Report C-28 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-23. External gamma shielding factor.

Characterization Report C-29 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-24. Fruit, vegetable and grain consumption.

Characterization Report C-30 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-25. Milk Consumption.

Characterization Report C-31 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-26. Soil Ingestion.

Characterization Report C-32 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-27. Drinking water intake.

Characterization Report C-33 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-28. Depth of soil mixing layer.

Characterization Report C-34 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-29. Depth of roots.

Characterization Report C-35 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-30. Wet weight crop yield for fodder.

Characterization Report C-36 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-31. Wet weight crop yield for leafy vegetables.

Characterization Report C-37 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-32. Wet weight crop yield for non-leafy vegetables.

Characterization Report C-38 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-33. Weathering removal constant for all vegetation.

Characterization Report C-39 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-34. Indoor time fraction.

Characterization Report C-40 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-35. Wind Speed.

Characterization Report C-41 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-36. Evapotranspiration coefficient.

Characterization Report C-42 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
C.2.1 Sensitivity Analysis Results –Industrial Worker Scenario
The results of the sensitivity analysis for the Industrial Worker scenario are provided in Figures C-37 through C-63. The doses based on the upper, middle and lower parameter values are provided in each figure, however, in several cases the doses are the same (i.e., parameter is not sensitive). The following
parameters were found to have the highest sensitivities in the Industrial Worker scenario: 1) Sorption coefficient (Kd) of the contaminated zone
2) Density of the contaminated zone
3) Runoff coefficient
4) External gamma shielding factor
5) Soil ingestion
6) Depth of soil mixing layer
7) Evapotranspiration coefficient.

Characterization Report C-43 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-37. Sorption coefficient (Kd) in the contaminated zone.

Characterization Report C-44 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-38. Sorption coefficient (Kd) in the unsaturated zone.

Characterization Report C-45 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-39. Sorption coefficient (Kd) in the saturated zone.

Characterization Report C-46 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-40. Density of the contaminated zone.

Characterization Report C-47 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-41. Density of the unsaturated zone.

Characterization Report C-48 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-42. Density of the saturated zone.

Characterization Report C-49 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-43. Total porosity of the contaminated zone.

Characterization Report C-50 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-44. Total porosity of the unsaturated zone.

Characterization Report C-51 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-45. Total porosity of the saturated zone.

Characterization Report C-52 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-46. Effective porosity of the unsaturated zone.

Characterization Report C-53 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-47. Effective porosity of the saturated zone.

Characterization Report C-54 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-48. Contaminated zone hydraulic conductivity.

Characterization Report C-55 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-49. Unsaturated zone hydraulic conductivity.

Characterization Report C-56 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-50. Saturated zone hydraulic conductivity.

Characterization Report C-57 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-51. Contaminated zone b parameter.

Characterization Report C-58 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-52. Unsaturated zone b parameter.

Characterization Report C-59 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-53. Saturated zone hydraulic gradient.

Characterization Report C-60 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-54. Runoff Coefficient.

Characterization Report C-61 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-55. Well pumping rate.

Characterization Report C-62 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-56. Inhalation rate.

Characterization Report C-63 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-57. Mass loading for inhalation.

Characterization Report C-64 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-58. External gamma shielding factor.

Characterization Report C-65 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-59. Soil Ingestion.

Characterization Report C-66 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-60. Drinking water intake.

Characterization Report C-67 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-61. Depth of soil mixing layer.

Characterization Report C-68 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-62. Wind Speed.

Characterization Report C-69 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020

Figure C-63. Evapotranspiration coefficient.

Characterization Report C-70 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
C.3 UNCERTAINTY ANALYSIS
Uncertainty analyses were conducted for the Resident Farmer and Industrial Worker scenarios for the parameters found to be the most sensitive based on the sensitivity analyses conducted in Section C.2.
Two uncertainty analyses were run for each of the Resident Farmer and Industrial Worker scenario consisting of (1) parameter uncertainty based on the lower quartile (25%) and upper quartile (75%) of the sensitive parameters based on the RESRAD-ONSITE parameter distributions provided in NUREG/CR-6697, and (2) parameter uncertainty based on sampling of the full RESRAD-ONSITE parameter distributions provided in NUREG/CR-6697. The parameter distribution parameter values for the quantile uncertainty analysis are provided in Table C-3. The parameter distributions used in the full distribution uncertainty analyses are provided in Table C-4. C.3.1 Uncertainty Analysis Results
The DCGL results of the uncertainty analyses are summarized in Table C-5. The base case DCGL model results based on the deterministic runs are also shown to provide a comparison to the uncertainty results. The full parameter distribution uncertainty results, based on the peak-of-the mean dose distribution, are in agreement with the deterministic base case model results. The peak-of-the-mean DCGLs are considered
to be appropriate to compare with the deterministic DCGLs because NRC indicates that when using probabilistic dose modeling, the peak-of-the-mean dose distribution should be used for demonstrating compliance with its License Termination Rule in 10 CFR 20, Subpart E (NUREG-1757).
The quantile parameter value uncertainty analyses produced DCGLs that were less than both the deterministic based case model DCGLs and the full parameter distribution uncertainty DCGLs. However,
the use of the lower and upper quantiles for the parameter values is considered overly conservative considering the conservatism already built into the conceptual models for the Resident Farmer and Industrial Worker scenarios. As noted in Section 4.3.3, the Resident Farmer and Industrial Worker scenarios assume that the entire volume of contaminated soil in a trench is exhumed and spread over the ground surface, resulting in a 6-inch contaminated soil layer. This is a conservative assumption based on Appendix J of NUREG-1757, where a dose assessment strategy for buried waste is provided. The use of this strategy simplifies the analysis and provides a conservative estimate of the radionuclide DCGLs.
In addition, several additional conservatisms were incorporated into the Resident Farmer and Industrial Worker scenarios. These conservatisms include the assumption that a Resident Farmer would actually be
able to develop a well in the area to provide water for farming (see Section 4.6). The Industrial Worker scenario also includes the conservative assumption that the worker would be present at this remote site with no facilities for 8 hours per day, 250 days per year for 30 years (see Section 4.3.2).
After consideration of the results of the probabilistic uncertainty analyses, and the conservatism built into the deterministic base case scenarios, it was determined that it is appropriate to use the deterministic base case DCGLs, supported by the peak-of-the-mean DCGLs, for the TR-5 and TR-6 DCGLs.

Characterization Report C-71 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Table C-3. Parameter values used in the quantile uncertainty analyses.
Parameter Description Code Quantile Value Quantile
Sorption coefficient (Kd) of Ra-226 in contaminated zone DCACTC 8514 Upper (75%)
Density of contaminated zone DENSCZ 1.675 Upper (75%)
Runoff coefficient RUNOFF 0.625 Upper (75%)
External gamma shielding factor SHF1 0.46 Upper (75%)
Fruit, vegetable, and grain consumptionb DIET(1) 238 Upper (75%)
Soil ingestion SOIL 23.6 Upper (75%)
Depth of soil mixing layer DM 0.15 Lower (25%)
Depth of rootsb DROOT 1.225 Lower (25%)
Indoor time fractionb FIND 0.66 Base value no change
Evapotranspiration coefficient EVAPTR 0.6875 Upper (75%)
a. The quantiles were determined from the RESRAD distributions in NUREG/CR-6697. b. These parameter distributions were not used in the Industrial Worker scenario quantile uncertainty analysis.

Characterization Report C-72 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Table C-4. Parameter values used in the full parameter distribution uncertainty analyses.
Parameter Description Code Distribution Description of Parameter Distribution
Kd of Ra-226 in contaminated zone DCACTC Lognormal-n μ Normal: 8.17 σ Normal: 1.7
Density of contaminated zone DENSCZ Truncated normal
μ: 1.52 σ: 0.23 Quantile, Minimum: 0.001 Quantile, Maximum: 0.999
Runoff coefficient RUNOFF Uniform Minimum: 0.1 Maximum: 0.8
External gamma shielding factor SHF1 Bounded lognormal-n
μ Normal: -1.3 σ Normal: 0.59 Minimum: 0.044 Maximum: 1
Fruit, vegetable, and grain consumptionb DIET(1) Triangular Minimum: 135 Mode: 178 Maximum: 318
Soil ingestion SOIL Triangular Minimum: 0 Mode: 18.3
Maximum: 36.5
Depth of soil mixing layer DM Triangular Minimum: 0 Mode: 0.15 Maximum: 0.6
Depth of rootsb DROOT Uniform Minimum: 0.3 Maximum: 4
Indoor time fractionb FIND Continuous linear
0.0 0.000 0.05 0.375 0.25 0.521 0.5 0.625 0.75 0.809 0.9 0.938 0.95 0.992 1.0 1.000
Wind speed WIND Bounded lognormal-n
μ Normal: 1.445 σ Normal: 0.2419
Minimum: 1.4 Maximum: 13
Evapotranspiration coefficient EVAPTR Uniform Minimum: 0.5 Maximum: 0.75
a. All distributions are RESRAD defaults available in NUREG/CR-6697. b. These parameter distributions were not used in the Industrial Worker scenario uncertainty analysis.

Characterization Report C-73 North Wind Services, LLC Area 2 SWMU 11 Dugway, Utah February 2020
Table C-5. Uncertainty Analysis Results.
Scenario
DCGL (pCi/g)
Base Case Quantile Uncertainty Full Distribution Uncertainty
Resident Farmer 7.4 4.4 7.5
Industrial Worker 55 51 54

C.4 REFERENCES
U.S. Nuclear Regulatory Commission, NUREG-1757, “Consolidated Decommissioning Guidance, Characterization, Survey, and Determination of Radiological Criteria,” Volume 2, Revision 1, September 2006.
U.S. Nuclear Regulatory Commission, NUREG/CR-6697, ANL/EAD/TM-98, “Development of Probabilistic RESRAD 6.0 and RESRAD-BUILD 3.0 Computer Codes,” November 2000.

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Appendix B
Ecological Risk Screening

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Final Feasibility Study B-3 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
ECOLOGICAL RISK SCREENING FOR TR-5 AND TR-6
INTRODUCTION
An ecological risk screening analysis was conducted for Area 2 of SWMU 11 TR-5 and TR-6 radiological
contaminants to confirm ecological receptors are not a driver for remedial actions. Biotic concentration guidelines (BCGs) were derived using the RESRAD-BIOTA computer model (DOE, 2004).
RESRAD-BIOTA DESCRIPTION
The RESRAD-BIOTA code (DOE, 2004) provides a complete spectrum of biota dose evaluation capabilities, from methods for general screening, to comprehensive receptor-specific dose estimation. The code was designed to be consistent with and provide a tool for implementing the DOE “Graded Approach
for Evaluating Radiation Doses to Aquatic and Terrestrial Biota” (DOE, 2002).
RESRAD-BIOTA SCREENING ASSUMPTIONS
Key assumptions used in deriving the BCGs that highlight the conservatism applied in the general screening model of RESRAD-BIOTA are presented below in Table 1. Exposure pathways for each of the reference organism types considered in the graded approach are presented below in Figures 1 and 2. A summary of the general dose equation and approach used to derive the BCGs is provided below in Table 2. The deer mouse (Peromyscus maniculatus) was selected as the species for evaluation because it was noted as the predominant rodent species in the area and would be representative of maximum potential exposure.
MODIFICATIONS to SCREENING DATA
The only modification to the RESRAD-BIOTA screening data and assumptions was for the area factor, which is a correction factor for exposure and receptor residence time for the selected organism for a finite
area of contamination. Due to the limited area of TR-5 and TR-6, this factor was modified for terrestrial animals to 0.2 based on the range of deer mice (Wood et al., 2010). Wood et. al., (2010) present the range of deer mice between 360-5,868 m2. Using the minimum deer mice range of 360 m2 and the area of TR-5
(i.e., minimum contamination area) of 72.65 m2, results in an area factor of 0.2 (i.e., 72.65 m2/360 m2 = 0.2)
The area factor for terrestrial plants was maintained at the default value of 1.0.
RESRAD-BIOTA BCGs
The RESRAD-BIOTA BCGs for terrestrial animal and terrestrial plants are provided below in Tables 3 and 4, respectively.
COMPARISON OF BCGs to TR-5 and TR-6 SOIL CONCENTRATIONS
A comparison of the maximum and average soil concentration and also the debris samples from Cabrera (2016) to the terrestrial animal BCGs are provided below in Table 5. The terrestrial animal BCGs provided the limiting BCGs.
The only exceedance of the terrestrial animal BCGs was for the maximum soil concentrations of Ra-226 at TR-5. However, it is highly unlikely that the animal would only be exposed to the maximum soil concentration. Therefore, the average soil concentration is considered a better metric of the soil
concentration to which the terrestrial animal would be exposed.
Based on the average soil concentrations at TR-5 and TR-6, the BCGs would not be exceeded. This
evaluation confirmed that there are no ecological COCs and therefore, remedial action is not required to address ecological exposure pathways.

Final Feasibility Study B-4 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
REFERENCES
Cabrera, 2016, Final Report: Area 2 Solid Waste Management Unit (SWMU) 11 Trenches TR-5 and TR-6,
Dugway Proving Ground, Dugway, Utah. September 2016.
DOE. 2002. DOE STANDARD: A GRADED APPROACH FOR EVALUATING RADIATION DOSES TO AQUATIC AND TERRESTRIAL BIOTA. DOE-STD-1153-2002. U.S. Department of
Energy Washington, D.C. 20585.
DOE. 2004. USER’S GUIDE, VERSION 1: RESRAD-BIOTA: A Tool for Implementing a Graded Approach to Biota Dose Evaluation. DOE/EH-0676. United States Department of Energy, Interagency Steering Committee on Radiation Standards. January 2004.
B.A. Wood, L. Cao, M.D. Dearing. 2010. Deer Mouse (Peromyscus maniculatus) Home-Range Size and Fidelity in Sage-Steppe Habitat. Western North American Naturalist, 70(3):345-354 (2010).

Final Feasibility Study B-5 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Table 1. Assumptions Regarding Sources, Receptors, and Routes of Exposure Applied in the RESRAD-BIOTA model.
Dose Limits • BCGs were derived for terrestrial plant and terrestrial animal reference
organisms. The dose rate limits used to derive the BCGs for each organism type are 1 rad/d, and 0.1 rad/d respectively.
• While existing effects data support the application of these dose limits to
representative individuals within populations of plants and animals, the assumptions and parameters applied in the derivation of the BCGs are based on a maximally exposed individual, representing a conservative approach for
screening purposes.
External Sources of Radiation Exposure • Estimates of the contribution to dose from external radioactive material were made assuming that all of the ionizing radiation was deposited in the organism (i.e., no pass-through and no self-shielding). This is conservative and is
tantamount to assuming that the radiosensitive tissues of concern (the reproductive tissues) lie on the surface of a very small organism.
• For external exposure to contaminated soil, the source was presumed to be
infinite in extent. In the case of external exposure to contaminated sediment and water, the source was presumed to be semi-infinite in extent.
• The source medium to which the organisms are continuously exposed is
assumed to contain uniform concentrations of radionuclides.
• These assumptions provide for appropriately conservative estimates of energy deposition in the organism from external sources of radiation exposure.
Internal Sources of
Radiation Exposure
• Estimates of the contribution to dose from internal radioactive material were
conservatively made assuming that all of the decay energy is retained in the tissue of the organism, (i.e., 100% absorption).
• Progeny of radionuclides and their decay chains are also included. This
provides an over-estimate of internal exposure, as the lifetime of many of the biota of interest is generally short compared to the time for the build-up of progeny for certain radionuclides.
• The radionuclides are presumed to be homogeneously distributed in the tissues of the receptor organism. This is unlikely to under-estimate the actual dose to the tissues of concern (i.e., reproductive organs).
• A radiation weighing factor of 20 for alpha particles is used in calculating the BCGs for all organism types. This is conservative, especially if non-stochastic effects are most important in determining harm to biota. The true
value may be a factor of 3 to 4 lower.

Final Feasibility Study B-6 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020

Figure 1. Exposure Pathways for Terrestrial Plants in the RESRAD-BIOTA Model.

Figure 2. Exposure Pathways for Terrestrial Animals in the RESRAD-BIOTA Model.

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Table 2. General Dose Equation and Approach Used to Derive BCGs in RESRAD -BIOTA.

• The limiting concentration in an environmental medium was calculated by first setting a target total dose (e.g., 1 rad/d for terrestrial plants, or 0.1 rad/d for terrestrial animals) and then back-calculating
to the medium concentration (i.e., the BCG) necessary to produce the applicable dose from radionuclides in the organism (internal dose), plus the external dose components from radionuclides in the environment (external dose).
• The denominator of the generic equation represents the dose per unit media concentration and may be broken down into the base components of internal and external dose. • Internal doses originate from radionuclides inside the organism’s body. The internal dose is calculated
as the product of the internal radionuclide concentration and internal dose conversion factor. External doses originate from radionuclides external to the organism and are calculated as the product of the radionuclide concentration in the environmental medium in which the organism resides and an
appropriate dose conversion factor.

Table 3. RESRAD-BIOTA BCGs for Terrestrial Animals. Terrestrial Animals
Nuclide BCG (pCi/g) Limiting Organism
C-14 2.38E+04 Yes
Cs-137 1.04E+02 Yes
Po-210 2.17E+04 Yes
Ra-226 2.53E+02 Yes
Sr-90 1.13E+02 Yes
Th-229 3.95E+03 Yes
Th-230 4.99E+04 Yes
Th-232 7.60E+03 Yes
U-234 2.57E+04 Yes
U-235 1.42E+04 Yes
U-238 7.90E+03 Yes

Table 4. RESRAD-BIOTA BCGs for Terrestrial Plants.
Terrestrial Plants
Nuclide BCG (pCi/g) Limiting Organism
C-14 6.07E+04 No
Cs-137 2.21E+03 No
Po-210 1.83E+05 No
Ra-226 2.88E+02 No
Sr-90 3.57E+03 No
Th-229 1.03E+04 No
Th-230 1.75E+05 No
Th-232 2.37E+04 No
U-234 5.16E+04 No
U-235 2.81E+04 No
U-238 1.57E+04 No

Final Feasibility Study B-8 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Table 5. Comparison of the BCGs to the TR-5 and TR-6 Soil Concentrations.
Nuclide BCG (pCi/g)
TR-5 (pCi/g) TR-6 (pCi/g)
Soil Max Soil Avg Debris Soil Max Soil Avg
C-14 2.38E+04 213 12.7 221 22.5
Cs-137 1.04E+02 1.6 0.13 1.22 0.34
Po-210 2.17E+04 3520
Ra-226 2.53E+02 3040 136.6 2.03 1.77
Sr-90 1.13E+02 19.2 1.2 0.17 0.06
Th-229 3.95E+03 30.6
Th-230 4.99E+04 0.74
Th-232 7.60E+03 0.84
U-234 2.57E+04 6.4 1.5 0.8 2.74 1.61
U-235 1.42E+04 0.13 0.04 0.13 0.29 0.13
U-238 7.90E+03 6.7 1.28 0.81 1.71 1.16

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Appendix C
MicroShield Modeling

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Final Feasibility Study C-3 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
MICROSHEILD MODELING FOR TR-5 AND TR-6 CAPS
INTRODUCTION
The MicroShield computer model (Grove Software, 2006) was used to evaluate the closure cap thickness
requirements for SWMU 11 TR-5 and TR-6. The closure cap thickness was based on an allowable dose of 25 mrem/yr for an industrial worker.
RADIONUCLIDE INVENTORY
The maximum radionuclide soil and/or debris concentrations for TR-5 and TR-6 were used in the analyses for conservatism and to ensure that the cap thicknesses were not underestimated. The maximum radionuclide concentrations for TR-6 and TR-5 were obtained from the validated data file from Cabrera (2016). The maximum radionuclide concentrations for TR-5 and TR-6 are provided in Tables 1 and 2, respectively.
Table 1. TR-6 maximum radionuclide soil concentrations.
Radionuclide Maximum Soil Concentration (pCi/g)
Cs-137 1.22
Nb-94 0.019
Ra-226 2.03
U-232 3.86
U-234 2.74
U-238 1.71

Table 2. TR-5 maximum radionuclide soil and debris concentrations.
Radionuclide
Maximum Soil Concentration (pCi/g)
Maximum Debris Concentration (pCi/g)
Cs-137 1.6 --
Nb-94 8.9 --
Ra-226 3,040 --
Pu-242 -- 19.7
Po-210 -- 3,520
Th-229 -- 30.6
Th-230 -- 0.74
U-232 3.91 26.2
U-234 6.4 0.8
U-235 0.13 0.13
U-238 6.7 0.81

Final Feasibility Study C-4 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
CLOSURE CAP AND SOIL COMPOSITION
The soil/cap composition for use in MicroShield was based on a silty soil used in the development of the
external dose conversion factors developed in EPA’s Federal Guidance Report 12 (EPA, 1993). This soil was assumed to have a density of 1.6 g/cm3 (EPA, 1993). The soil composition is provided in Table 3.
Table 3. Soil Composition of a silty sand (EPA, 1993).
Element Mass Fraction
H 0.021
C 0.016
O 0.577
Al 0.050
Si 0.271
K 0.013
Ca 0.041
Fe 0.011
Total 1.000

MICROSHIELD INPUT PARAMETERS
The MicroShield input parameter values for TR-5 and TR-6 are provided in Table 4
Table 4. MicroShield Input Parameter Values.
Parameter TR-5 Value TR-6 Value
Trench Length (m) 14.02 12.19
Trench Width (m) 5.18 6.096
Trench Depth (m) 2.13 1.83
Dose Point (m) 1 m above ground surface 1 m above ground surface
Radionuclide Inventory See Table 2 See Table 1
Soil/Cap Composition See Table 3 See Table 3
Buildup Material Based on air gap between ground surface and dose point Based on air gap between ground surface and dose point

MICROSHIELD RESULTS
The TR-6 cap exposure rates, based on the maximum soil concentrations, are provided in Table 5 for various decay/ingrowth times. The maximum soil concentrations were assumed to be homogenous throughout the 12.19 m (40 ft) by 6.096 (20 ft) by 1.83 m (6 ft) trench.

Final Feasibility Study C-5 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Table 5. TR-6 no cap exposure rates for different source decay times.
Decay Time (yr) Exposure Rate (mR/hr)
0 6.66E-04
1 5.59E-03
5 8.50E-03
10 8.98E-03
15 8.81E-03
50 7.09E-03
100 5.50E-03
500 2.73E-03
1,000 2.17E-03

The maximum exposure rate occurs at 10 years of decay/ingrowth for the maximum soil concentrations at TR-6, with an exposure rate of 8.98E-03 mR/hr. Based on an allowable dose of 25 mrem/yr, this exposure rate results in an allowable exposure time of 2,783 hours per year (i.e., conservatively assuming that 1 mR equals 1 mrem). 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 ℎ𝑎𝑎𝑜𝑜𝑜𝑜𝑜𝑜= 25 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚/𝑦𝑦𝑚𝑚8.98𝐸𝐸−03 𝑚𝑚𝑚𝑚/ℎ𝑚𝑚=2783 hr/yr
Therefore, for an industrial worker, no cap is required at TR-6 for exposure durations of 2,783 hours per year or less.
The TR-5 cap exposure rates, based on the maximum soil and/or debris concentrations, are provided in
Table 6 for various decay/ingrowth times. The maximum soil concentrations were assumed to be homogenous throughout the 14.02 m (46 ft) by 5.18 m (17 ft) by 2.13 m (7 ft) trench.
Table 6. TR-5 no cap exposure rates for different source decay times.
Decay Time
(yr)
Exposure Rate
(mR/hr)
0 2.732E-02
1 4.712
5 4.724
10 4.717
25 4.683
50 4.626
100 4.518
500 3.788
1,000 3.052

Final Feasibility Study C-6 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
The maximum exposure rate occurs at 5 years of decay/ingrowth for the maximum soil/debris concentrations at TR-5, with an exposure rate of 4.724 mR/hr. Based on an allowable dose of 25 mrem/yr,
this exposure rate results in an allowable exposure time of 5.3 hours/yr (i.e., conservatively assuming that 1 mR equals 1 mrem). 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 ℎ𝑎𝑎𝑜𝑜𝑜𝑜𝑜𝑜= 25 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚/𝑦𝑦𝑚𝑚4.724 𝑚𝑚𝑚𝑚/ℎ𝑚𝑚=5.3 hr/yr
Therefore, for an industrial worker, a cap would be required for exposure durations greater than 5.3 hours per year.
The allowable worker hours for various cap thicknesses was evaluated in MicroShield based on the
maximum soil/debris soil concentrations at the maximum decay/ingrowth time of 5 years. The results of the cap thickness evaluation are provided in Table 7 and Figure 1.
Table 7. TR-5 allowable worker exposure hours for various cap thicknesses, based on 25 mrem.
Cap Thickness Allowable Worker Exposure Duration (hr/yr)
0.0 m (0.0 ft) 5.3
0.1524 m (0.5 ft) 22.3
0.3048 m (1.0 ft) 87.7
0.4572 m (1.5 ft) 316.9
0.6096 m (2.0 ft) 1,078.5
0.7620 m (2.5 ft) 3,523.6
0.9144 m (3.0 ft) 11,210.8

Figure 1. TR-5 allowable worker exposure hours for various cap thicknesses, based on 25 mrem/yr.
1
10
100
1000
10000
100000
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
Al
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o
w
a
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E
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p
o
s
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e

T
i
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f
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2
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m
r
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/
y
r

(h
o
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r
s
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Soil Thickness (ft)

Final Feasibility Study C-7 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
REFERENCES
Cabrera, 2016, Final Report: Area 2 Solid Waste Management Unit (SWMU) 11 Trenches TR-5 and
TR-6, Dugway Proving Ground, Dugway, Utah. September 2016.
EPA, 1993, Federal Guidance Report No. 12: External Exposure to Radionuclides in Air, Water, and Soil, EPA-402-R-93-081. Keith F. Eckerman and Jeffrey C. Ryman. September 1993.
Grove Software, 2006, MicroShield User’s Manual, Version 7. Grove Software, Inc., Lynchburg, Virginia. October 2006.

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Final Feasibility Study D-1 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Appendix D
Exposure Rate Reduction Modeling

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Final Feasibility Study D-3 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
GROUT STABILIZATION EXPOSURE RATE REDUCTION FOR TR-5 AND TR-6 INTRODUCTION
The MicroShield computer model (Grove Software 2006) was used to evaluate the exposure rate
reductions for SWMU 11 TR-5 and TR-6 due to in-situ grout stabilization of the waste.
RADIONUCLIDE INVENTORY
The maximum radionuclide soil and/or debris concentrations for TR-5 and TR-6 were used in the analyses. The maximum radionuclide concentrations for TR-6 and TR-5 were obtained from the validated data file from Cabrera (2016). The maximum radionuclide concentrations for TR-5 and TR-6 are
provided in Table 1 and 2, respectively.
Table 1. TR-6 maximum radionuclide soil concentrations.
Radionuclide Maximum Soil Concentration (pCi/g)
Cs-137 1.22
Nb-94 0.019
Ra-226 2.03
U-232 3.86
U-234 2.74
U-238 1.71

Table 2. TR-5 maximum radionuclide soil and debris concentrations.
Radionuclide Maximum Soil Concentration (pCi/g) Maximum Debris Concentration (pCi/g)
Cs-137 1.6 --
Nb-94 8.9 --
Ra-226 3,040 --
Pu-242 -- 19.7
Po-210 -- 3,520
Th-229 -- 30.6
Th-230 -- 0.74
U-232 3.91 26.2
U-234 6.4 0.8
U-235 0.13 0.13
U-238 6.7 0.81

Final Feasibility Study D-4 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
SOIL AND CONCRETE COMPOSITION
The soil composition for use in MicroShield was based on a silty soil used in the development of the
external dose conversion factors developed in EPA’s Federal Guidance Report 12 (EPA 1993). This soil was assumed to have a density of 1.6 g/cm3 (EPA 1993). The soil composition is provided in Table 3.
The grout was represented by the National Bureau of Standards (NBS) concrete composition that is provided with the MicroShield model. The concrete has a density of 2.35 g/cm3 and the composition is provided in Table 4.
Table 3. Soil composition of a silty sand (EPA 1993).
Element Mass Fraction
H 0.021
C 0.016
O 0.577
Al 0.050
Si 0.271
K 0.013
Ca 0.041
Fe 0.011
Total 1.000

Table 4. NBS concrete composition.
Element Mass Fraction
H 0.0056
O 0.4983
Na 0.0171
Mg 0.0024
Al 0.0456
Si 0.3158
S 0.0012
K 0.0192
Ca 0.0826
Fe 0.0122
Total 1.000

Final Feasibility Study D-5 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
MICROSHIELD INPUT PARAMETERS
The MicroShield input parameter values for TR-5 and TR-6 are provided in Table 5.
Table 5. MicroShield Input Parameter Values.
Parameter TR-5 Value TR-6 Value
Trench Length (m) 14.02 12.19
Trench Width (m) 5.18 6.096
Trench Depth (m) 2.13 1.83
Dose Point (m) 1 m above ground surface 1 m above ground surface
Radionuclide Inventory See Table 2 See Table 1
Soil Composition See Table 3 See Table 3
Concrete Composition See Table 4 See Table 4
Buildup Material Based on air gap between
ground surface and dose point
Based on air gap between
ground surface and dose point

MICROSHIELD RESULTS
The exposure rate reduction from the in-situ grouting of waste at TR-5 and TR-6 are presented in Table 6.
The exposure rate due to in-situ grouting of the waste results in an exposure rate reduction of 30%.
Table 6. Exposure rate reduction for in-situ grouting of the waste at TR-5 and TR-6.
Trench
Exposure Rate (mR/hr)
Exposure Reduction Soil Concrete
TR-5 4.724 3.303 0.30
TR-6 8.984E-03 6.265E-03 0.30

REFERENCES
Cabrera, 2016. Final Report: Area 2 Solid Waste Management Unit (SWMU) 11 Trenches TR-5 and TR-6, Dugway Proving Ground, Dugway, Utah. September 2016.
EPA. 1993. Federal Guidance Report No. 12: External Exposure to Radionuclides in Air, Water, and Soil. EPA-402-R-93-081. Keith F. Eckerman and Jeffrey C. Ryman. September 1993.
Grove Software. 2006. MicroShield User’s Manual, Version 7. Grove Software Inc. Lynchburg, VA.
October 2006.

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Final Feasibility Study E-1 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
Appendix E
Cost Estimate Evaluation

Final Feasibility Study E-2 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
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Final Feasibility Study E-3 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
DUGWAY PROVING GROUND BASIS OF COST ESTIMATES
November 2019
RACER® provides users with the ability to document estimates at every level of the estimating hierarchy. This capability has been included in the system so that the rationale for estimates can be documented and understood by others and reconstructed later.
Remedial Alternative 2- Land Use Controls
• Institutional Controls
o Site use controls
o Remedial Design o Land Use Control Implementation Plan (LUCIP) o LUCIP Meetings (2)
o Access Control Signs (4) o Annual Inspection.
• Install Fencing
o Fencing around both sites o Fencing around each site individually.
Remedial Alternative 3- Containment & LUCs
• Institutional Controls
o Site use controls o Remedial Design o LUCIP
o LUCIP Meetings (2) o Access Control Signs (4) o Annual Inspection.
• Install Fencing
o Fencing around both sites
o Fencing around each site individually.
• RCRA Hazardous Waste Cap- geosynthetic clay liner (GCL) – TR-5 and TR-6
o Based on Microshield, protective cover of 3 ft o Total area of 120 ft × 70 ft (8,400 ft2 to cover both trenches individually) o 40-mil HDPE geomembrane
o 36-inch protective cover.
Remedial Alternative 4- Excavation, Off-Site Disposal, and Backfilling (complete after 2 years)
• Documentation, planning, and meetings.
• Excavation
o Excavate a total of 1,000 CY from both trenches combined. Excavate to a depth of 7 ft bgs.
o Set up temporary containment area for storage of excavated material o Post-excavation confirmation sampling for radionuclides o Backfill with certified clean fill
o Restore surface with native vegetation.

Final Feasibility Study E-4 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020
• Dispose of 1,000 CY of low-level waste (LLW) at Energy Solutions- Clive facility as bulk material.
Remedial Alternative 5- Excavation, Sorting, Screening, and Off-Site Disposal (complete after 2 years)
• Documentation, planning, and meetings.
• Excavation
o Excavate a total of 1,000 CY from both trenches combined. Excavate to a depth of 7 ft bgs. o Set up temporary containment area for storage of excavated material o Post-excavation confirmation sampling for radionuclides
o Backfill with certified clean fill o Restore surface with native vegetation.
• On-Site Radiological Screening
o Mobilize and demobilize soil screening equipment o Pretreat the soils by screening and tilling excavated material
o Process 1,000 CY o Assume 20% contamination level.
• Dispose of 200 CY of LLW at Energy Solutions- Clive facility as bulk material.
Remedial Alternative 6- Soil Stabilization
• Institutional Controls
o Site use controls o LUCIP
o LUCIP Meetings (2) o Access Control Signs (4) o Periodic Inspection and maintenance.
• Install Fencing
o Fencing around both sites
o Fencing around each site individually.
• In-Situ Grouting (Portland cement or acrylamide)
o Grout injected under pressure across surface area of 1,782 ft2
o Injected to a depth of 10 ft bgs o Injection radius of influence 6 ft in diameter
o Pilot test and geotechnical testing.
Timeframe: 30 years
Alternatives Total Cost Capital Costs Total O&M and Periodic Costs Present Worth Value
Alternative 1 – No Action $0 $0 $0 $0
Alternative 2 - LUCs $167,241 $146,075 $19,270 $160,547
Alternative 3 - Containment and LUCs $383,000 $156,000 $116,000 $383,000
Alternative 4 - Excavate, Dispose $592,757 $592,757 $0 $592,757
Alternative 5 - Excavate, Screen, Dispose $1,439,237 $1,439,237 $0 $1,439,237
Alternative 6 - Soil Stabilization $487,000 $454,000 $29,000 $481,000

Final Feasibility Study E-5 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020

Final Feasibility Study E-6 North Wind Services, LLC Area 2 SWMU-11 Dugway, Utah August 2020