Loading...
HomeMy WebLinkAboutDRC-2014-003041 - 0901a0688042eec2GF ^•r m ENE ENERGY FUELS Energy Fuels Resources (USA) Inc. 225 Union Blvd. Suite 600 Lakewood, CO. US, 80228 303 974 2140 www.energyfuels.com HAND DELIVERY APR 2 9 20U o o i\9 f?ad VIA EMAIL AND OVERNIGHT DELIVERY April 25, 2014 Mr. Bryce Bird Director, Utah Division of Air Quality State of Utah Department of Environmental Quality 195 North 1950 West Salt Lake City, UT84116 DRC-2014-003041 Re: White Mesa Uranium Mill, National Emissions Standards for Radon Emission from Operating Mill Tailings Transmittal of March 2014 Monthly Radon Flux Monitoring Report for Cell 2 Dear Mr. Bird: This letter transmits Energy Fuels Resources (USA) Inc's ("EFRI's") radon-222 flux monitoring report for March 2014 (the "Monthly Report") consistent with 40 CFR 61.254(b), for Cell 2 at the White Mesa Uranium Mill (the "Mill"). As discussed in our 2012 Annual Radon Flux Monitoring Report submitted March 29, 2013, the radon flux from Cell 2 during 2012 was higher than the 20 pCi/(m2 -sec) set out in 40 CFR 61.252(a). Although Cell 2 is no longer in operation, this Monthly Report is being submitted consistent with the requirements of 40 CFR 261(b) applicable to operating tailings impoundments. Included with the Monthly Report is a Radon Flux Measurement Program Report, dated March 2014, prepared by Tellco Environmental (the "Tellco March 2014 Monthly Report"). The Tellco March 2014 Monthly Report indicates that for the month of March 2014, the average radon flux from Cell 2 was 16.4 pCi/(m -sec), which is lower than the 20 pCi/(m2-sec) set out in 40 CFR 61.252(a). If you have any questions, please feel free to contact me at (303) 389-4167. Yours very truly, Energy EueTs Resources (USA) Inc. Jaime Massey Regulatory Compliance Specialist N:\WMM\Required Reports\NESHAPS Reports\2014 Monthly NESHAPs reports\March 2014\transmitall letter March 2014.doc Letter to B. Bird April 25, 2014 Page 2 of 2 cc: David C. Frydenlund Phil Goble, Utah DRC Dan Hillsten Rusty Lundberg, Utah DRC Jay Morris, Utah DAQ Harold R. Roberts David E. Turk Kathy Weinel Director, Air and Toxics Technical Enforcement Program, Office of Enforcement, Compliance and Environmental Justice, U. S. Environmental Protection Agency Attachments ENERGY FUELS RESOURCES (USA) INC. 40 CODE OF FEDERAL REGULATIONS 61 SUBPART W WHITE MESA MILL SAN JUAN COUNTY, UTAH TAILINGS CELL 2 MONTHLY COMPLIANCE REPORT FOR MARCH 2014 Submitted April 25, 2014 by Energy Fuels Resources (USA) Inc. 225 Union Blvd. Suite 600 Lakewood, Colorado 80228 (303) 974-2140 1) Name and Location of the Facility Energy Fuels Resources (USA) Inc. ("EFRI") operates the White Mesa Mill (the "Mill"), located in central San Juan County, Utah, approximately 6 miles (9.5 km) south of the city of Blanding. The Mill can be reached by private road, approximately 0.5 miles west of Utah State Highway 191. Within San Juan County, the Mill is located on fee land and mill site claims, covering approximately 5,415 acres, encompassing all or part of Sections 21, 22, 27, 28, 29, 32, and 33 of T37S, R22E, and Sections 4, 5, 6, 8, 9, and 16 of T38S, R22E, Salt Lake Base and Meridian. All operations authorized by the Mill's State of Utah Radioactive Materials License are conducted within the confines of the existing site boundary. The milling facility currently occupies approximately 50 acres and the tailings disposal cells encompass another 275 acres. 2) Monthly Report Although Cell 2 is no longer in operation, this Report is being submitted as a monthly report for the Mill's Cell 2 for March 2014, consistent with 40 Code of Federal Regulations (CFR) 61.254(b) applicable to operating tailings impoundments. A summary of the events that gave rise to EFRFs decision to file this monthly report consistent with 40 CFR 61.254(b) is set out in Section 4 of this Report. A summary of the radon emissions from Cell 2 measured in March 2014 is set out in Section 5 of this Report. The monthly monitoring data for March 2014, consistent with 40 CFR 61.254(b), is provided in Attachment 1 to this Report, which contains the Radon Flux Measurement Program Report, dated March 2014, prepared by Tellco Environmental (the "Tellco March 2014 Monthly Report"). The results are summarized in Section 5 of this Report. 3) Name of the Person Responsible for Operation and Preparer of Report Energy Fuels Resources (USA) Inc. 225 Union Boulevard, Suite 600 Lakewood, Colorado 80228 303.628.7798 (phone) 303.389.4125 (fax) EFRI is the operator of the Mill and its tailings impoundments (Cells 2, 3, and 4A) and evaporation impoundments (Cells 1 and 4B). The Mill is an operating conventional uranium mill, processing both conventional ores and alternate feed materials. The "method of operations" at the Mill is phased disposal of tailings. The annual radon emissions for existing impoundments are measured using Large Area Activated Charcoal Canisters in conformance with 40 CFR, Part 61, Appendix B, Method 115, Restrictions to Radon Flux Measurements, (Environmental Protection Agency ["EPA"], 2008). These canisters are passive gas adsorption sampling devices used to determine the flux rate of Radon-222 gas from the surface of the tailings material. For impoundments licensed for use after December 15, 1989 (i.e., Cell 4A, and 4B), EFRI employs the work practice standard listed at 40 CFR 61.252(b)(1) in that all tailings impoundments constructed or licensed after that date are lined, are no more than 40 acres in area, and no more than two impoundments are operated for tailings disposal at any one time. Although Cell 2 is no longer in operation, EFRI is submitting this monthly compliance report consistent with the standards in 40 CFR 61.254(b) applicable to operating tailings impoundments. 2 4) Background Information -- Summary of 2012 Annual Report Facility History Cells 2 and 3, which have surface areas of 270,624 m2 (approximately 66 acres) and 288,858 m2 (approximately 71 acres), respectively, were constructed prior to December 15, 1989 and are considered "existing impoundments" as defined in 40 CFR 61.251. Radon flux from Cells 2 and 3 is monitored annually, as discussed below. Cells 4A and 4B were constructed after December 15, 1989, and are subject to the work practice standards in 40 CFR 61.252(b)(1), which require that the maximum surface area of each cell not exceed 40 acres. For this reason, Cells 4A and 4B are not required to undergo annual radon flux monitoring. Cell 3, which is nearly filled, and Cell 4A, receive the Mill's tailings sands. Cells 1 and 4B, receive solutions only, and are in operation as evaporation ponds. Cell 2 is filled with tailings, is covered with an interim soil cover, and is no longer in operation. Dewatering of Cell 2 The Utah Division of Water Quality issued Groundwater Discharge Permit ("GWDP') UGW-370004 in 2005. Under Part I.D.3 of the current GWDP, EFRI has been required to accelerate dewatering of the solutions in the Cell 2 slimes drain. Dewatering of Cell 2 began in 2008. In mid-2011, changes were made in the pumping procedures for slimes drain dewatering of Cell 2 that resulted in an acceleration of dewatering since that time. As discussed in more detail below, studies performed by EFRI indicate that the increase in radon flux from Cell 2 has likely been caused by these dewatering activities. No other changes appear to have occurred in condition, use, or monitoring of Cell 2 that could have resulted in an increase in radon flux from the cell. The average water level in the Cell 2 slimes drain standpipe for each of the years 2008 through 2013 indicate that water levels in Cell 2 have decreased approximately 3.98 feet (5600.56 to 5596.58 fmsl) since 2008. Of this decrease in water level, approximately 1 foot occurred between 2010 and 2011, reflecting the improved dewatering that commenced part way through 2011, and approximately 2 feet between 2011 and 2013, reflecting improved dewatering for all of 2012 and 2013. Radon Flux Monitoring of Cell 2 Tellco performed the 2012 radon flux sampling during the second quarter of 2012 in the month of June. On June 25, 2012, Tellco advised EFRI that the average radon flux for Cell 2 from samples taken in June 2012 was 23.1 pCi/(m2-sec) (referred to in the Tellco report as pCi/m2-s), which was higher than the 20 pCi/(m2 -sec) standard referred to in 40 CFR 61.252(a). The result of the 2012 radon-222 flux monitoring for Cell 3 was 18 pCi/(m2 -sec). Cell 3, therefore, was in compliance with this standard for 2012. The results of the 2013 Cell 3 radon-222 flux monitoring were discussed in the 2013 Annual Radon Flux Monitoring Report for Cell 3 submitted on March 27, 2014. 40 CFR 61.253 provides that: "When measurements are to be made over a one year period, EPA shall be provided with a schedule of the measurement frequency to be used. The schedule may be submitted to EPA prior to or after the first measurement period." 3 EFRI advised the Utah Division of Air Quality ("DAQ"), by notices submitted on August 3 and September 14, 2012, that EFRI planned to collect additional samples from Cell 2 in the third and fourth quarters of 2012. These samples were collected on September 9, October 21, and November 21, 2012, respectively. As the June 2012 monitoring for Cell 3 indicated that it was in compliance with the standard, further monitoring of Cell 3 was not performed. The result of the 2012 radon-222 flux monitoring for Cell 2 was 25.9 pCi/(m2 -sec) (averaged over four monitoring events). The measured radon flux from Cell 2 in 2012 was therefore higher than the standard of 20 pCi/(m2 -sec) referred to in 40 CFR 61.252(a). The Cell 2 and Cell 3 radon flux results were reported in EFRFs 2012 Annual Radon Flux Monitoring Report (the "2012 Annual Report"). The provisions of 40 CFR 61.254(b) requires that: "If the facility is not in compliance with the emission limits of paragraph 61.252 in the calendar year covered by the report, then the facility must commence reporting to the Administrator on a monthly basis the information listed in paragraph (a) of this section, for the preceding month. These reports will start the month immediately following the submittal of the annual report for the year in non-compliance and will be due 30 days following the end of each month." This Report is being submitted as a monthly report for March 2014 for Cell 2, consistent with the requirements set out in 40 CFR 61.254(b). Monthly monitoring will continue until US EPA or DAQ advises EFRI that such monthly monitoring need not be continued. Evaluation of Potential Factors Affecting Radon Flux In an attempt to identify the cause of the increase in radon flux at Cell 2, EFRI conducted a number of evaluations in 2013, including: • Excavation of a series of 10 test pits in the Cell 2 sands to collect additional information needed to ascertain factors affecting radon flow path and flux, • Evaluation of radon trends relative to slimes drain dewatering, • Development of correlation factors relating dewatering rates to radon flux, and • Estimation of the thickness of temporary cover that would be required to reduce radon flux to levels lower than 20 pCi/(m2 -sec), during the dewatering process. These studies and results are discussed in detail in EFRFs 2012 Annual Radon Flux Report and summarized in the remainder of this section. Slimes drain dewatering data indicate that a lowering of the water level in Cell 2 has resulted in an increase in the average radon flux, and that an increase in water level has resulted in a decrease in the average radon flux. Changes in radon flux have consistently been inversely proportional to changes in water levels in Cell 2 since 2008. For the last three years the change in radon flux has been between 3 and 5 pCi/(m2-sec) per each foot of change in water level. It is also noteworthy that the significant increases in radon flux from Cell 2 which occurred between 2010 and 2011 and between 2011 and 2012 coincided with the periods of improved (accelerated) dewatering of Cell 2. 4 EFRI has evaluated these results and has concluded that the increase in radon-222 flux from Cell 2 in excess of 20 pCi/(m2 -sec) is most likely the unavoidable result of Cell 2 dewatering activities mandated by the Mill's State of Utah GWDP. This is due to the fact that saturated tailings sands attenuate radon flux more than dry tailings sands, and the thickness of saturated tailings sands decrease as dewatering progresses. There appear to have been no other changes in conditions at Cell 2 that could have caused this increase in radon flux from Cell 2. These conclusions are supported by evaluations performed by SENES Consultants Limited ("SENES"), who were retained by EFRI to assess the potential effects of dewatering on the radon flux from Cell 2 and to provide calculations of the thickness of temporary cover required to achieve the radon flux standard during the dewatering process. SENES' evaluations were presented in a report provided as an attachment to EFRI's 2012 Annual Report. SENES estimated a theoretical radon flux from the covered tailings at Cell 2 for various depths (thicknesses) of dry tailings, and predicted future increases in radon flux as a function of decreases in water levels. In order to explore potential interim actions that could be taken to maintain radon flux at levels at or below 20 pCi/(m2-sec), the SENES study also evaluated the extent to which radon emanations from the cell can be reduced by increasing the thickness of the current interim cover on Cell 2. 5) March 2014 Results Detailed results for March 2014 for Cell 2 are contained in the Tellco March 2014 Monthly Report. As described in the Tellco March 2014 Monthly Report, monitoring was performed consistent with 40 CFR 61 Subpart W Appendix B, Method 115 radon emissions reporting requirements. The radon monitoring consisted of 100 separate monitoring points at which individual radon flux measurements have been made by collection on carbon canisters. The individual radon flux measurements were averaged to determine whether they exceeded 20 pCi/(m2-sec). The average radon flux for Cell 2 in March 2014 was reported by Tellco to be 16.4 pCi/(m2 -sec). 6) Other Information Status of Proposed Updated Final Cover Design As part of developing the Mill's final reclamation plan required to achieve the radon flux standard of 20 pCi/(m2-sec), a final engineered cover design was submitted by TITAN Environmental in 1996 and approved by the US Nuclear Regulatory Commission ("NRC"). An updated final cover design for the Mill's tailings system, submitted in November 2011, is under review by the Utah Division of Radiation Control ("DRC"), and is not currently approved. DRC provided a second round of interrogatories on the proposed cover design and associated Infiltration and Contaminant Transport Model ("ICTM") in February 2013, for which EFRI and its consultant, MWH Inc. are preparing responses. 7) Additional Information Required for Monthly Reports a) Controls or Other Changes in Operation of the Facility 40 CFR 61.254(b)(1) states that in addition to all the information required for an Annual Report under 40 CFR 61.254(b), monthly reports provided under that section shall also include a description of all controls or other changes in operation of the facility that will be or are being installed to bring the facility into compliance. 5 Based on the evaluations described in Section 4, above, and as discussed during EFRI's March 27, 2013 meeting with DAQ and DRC staff, in addition to the monthly monitoring reported in this Monthly Report, EFRI has performed the following steps to ensure that radon emissions from Cell 2 are kept as low as reasonably achievable and at or below 20 pCi/(m2-sec). Construction and Monitoring of Interim Cover Test Area, and Application of Additional Random Fill i. EFRI constructed 12 test areas on Cell 2 to assess the effect of the addition of one foot of additional soil cover. EFR applied one foot of random fill moistened and compacted by a dozer to 12 circular test areas of approximately 100 to 120 feet in diameter. The total tested area is larger than the single 100 foot by 100 foot area proposed in previous Cell 2 monthly radon flux monitoring reports. Installation of 12 test areas containing the additional 1 foot of compacted soil was completed by August 2, 2013. Wetting and re-compaction of all 12 areas was completed prior to the start of the September 21, 2013 monthly flux monitoring event. ii. The radon flux has been monitored monthly at 100 locations on Cell 2, including the 12 test areas, since April 2013. iii. The effectiveness of the additional compacted cover at the 12 test areas will be evaluated over the next several months. If the desired reduction (to 20 pCi/(m2-sec) or lower) is achieved on the test areas, EFRI will apply additional random fill at 90% compaction, to the remainder of Cell 2, on or before July 1, 2014. Based on discussions with DRC, EFRI will proceed with the application of cover and will provide a letter to DRC with information demonstrating that the application of soil cover is consistent with the design and QC requirements of the proposed Reclamation Plan, currently under revision, on the understanding that the application of cover will be credited toward the final cover design. Interim Corrective Action EFRI has taken the following additional steps to provide interim mitigation of radon flux from Cell 2. EFRI has identified the areas of elevated radon flux associated with known sources of radiological contamination at or near the surface of the cell cover. Specifically: • Windblown tailings from Cell 3 which have been deposited on Cell 2 as Cell 3 is being closed have been removed and re-buried in Cell 3. A berm approximately five feet high, extending the length of the Cell 3 beach has been constructed at the edge of Cell 2, to prevent further carryover of sands from Cell 3 onto the Cell 2 cover prior to closure of Cell 3. • Any contaminated material near the surface of Cell 2 has been reburied. • Additional cover material has been added to each of 12 identified areas of elevated flux on Cell 2. • Monthly radon flux monitoring to assess the effectiveness of the above actions is ongoing. b) Facility's Performance Under Terms of Judicial or Administrative Enforcement Decree The Mill is not under a judicial or administrative enforcement decree. 6 8) Certification I Certify under penalty of law that I have personally examined and am familiar with the information submitted herein and based on my inquiry of those individuals immediately responsible for obtaining the information, I believe that the submitted information is true, accurate and complete. I am aware that there are significant penalties for submitting false information including the possibility of fine and imprisonment. See 18, U.S.C. 1001. Harold'R. Roberts Executive Vice President and Chief Operating Officer ATTACHMENT 1 National Emissions Standards for Hazardous Air Pollutants 2014 Radon Flux Measurement Program March 2014 Sampling Results National Emission Standards for Hazardous Air Pollutants 2014 Radon Flux Measurement Program White Mesa Mill 6425 South Highway 191 Blanding, Utah 84511 March 2014 Sampling Results Cell 2 Prepared for: Energy Fuels Resources (USA) Inc. 6425 S. Highway 191 P.O. Box 809 Blanding, Utah 84511 Prepared by: Tellco Environmental P.O. Box 3987 Grand Junction, Colorado 81502 TABLE OF CONTENTS Page 1. INTRODUCTION 1 2. SITE HISTORY AND DESCRIPTION 1 3. REGULATORY REQUIREMENTS FOR THE SITE 2 4. SAMPLING METHODOLOGY 2 5. FIELD OPERATIONS 3 5.1 Equipment Preparation 3 5.2 Sample Locations, Identification, and Placement 3 5.3 Sample Retrieval 4 5.4 Environmental Conditions 4 6. SAMPLE ANALYSIS 4 6.1 Apparatus 4 6.2 Sample Inspection and Documentation 5 6.3 Background and Sample Counting 5 7. QUALITY CONTROL (QC) AND DATA VALIDATION 5 7.1 Sensitivity 6 7.2 Precision 6 7.3 Accuracy 6 7.4 Completeness 6 8. CALCULATIONS 6 9. RESULTS 7 9.1 Mean Radon Flux 7 9.2 Site Results 8 References 9 Figure 1 10 Appendix A. Charcoal Canister Analyses Support Documents Appendix B. Recount Data Analyses Appendix C. Radon Flux Sample Laboratory Data, Including Blanks Appendix D. Sample Locations Map (Figure 2) i 1. INTRODUCTION During March 26-27, 2014 Tellco Environmental, LLC (Tellco) of Grand Junction, Colorado, provided support to Energy Fuels Resources (USA) Inc. (Energy Fuels) to conduct radon flux measurements at its White Mesa Mill site regarding the required National Emission Standards for Hazardous Air Pollutants (NESHAPs) Radon Flux Measurements. These measurements are required of Energy Fuels to show compliance with Federal Regulations (further discussed in Section 3 below). The standard is not an average per facility, but is an average per radon source. The standard allows mill owners or operators the option of either making a single set of measurements to represent the year or making multiple measurements over a one year period (e.g., weekly, monthly, or quarterly intervals). Energy Fuels is presently performing radon flux measurements on a monthly basis at Cell 2. Prior to 2012, Energy Fuels had been making a single set of measurements to represent the radon flux each year; however, as the radon flux levels began exceeding the regulatory standard of 20 picoCuries per square meter per second (pCi/m2-s) in 2012, Energy Fuels responded by opting to make the radon flux measurements on a more frequent basis. This report presents the radon flux measurements results only for Cell 2 for March 2014; the results of the radon flux sampling for Cell 3, which is presently on a quarterly sampling basis, are presented in a separate report. Also, in response to the increase in the radon flux rates, Energy Fuels has placed approximately 19,432 cubic meters of additional material, varying in depth from approximately 31-61 centimeters, throughout an area of approximately 50,130 square meters (m2). At this time, Energy Fuels has suspended the placement of additional cover materials at Cell 2 because the average flux rate has been below the regulatory standard for several months. Tellco was contracted to provide radon canisters, equipment, and canister-placement personnel as well as lab analysis of samples collected. Energy Fuels personnel provided support for loading and unloading charcoal from the canisters. This report details the procedures employed by Energy Fuels and Tellco to obtain the results presented in Section 9.0 of this report. 2. SITE DESCRIPTION The White Mesa Mill facility is located in San Juan County in southeastern Utah, six miles south of Blanding, Utah. The mill began operations in 1980 for the purpose of extracting uranium and vanadium from feed stocks. Processing effluents from the operation are deposited in lined cells, which vary in depth. Cell 1, Cell 4A, and Cell 4B did not require radon flux sampling, as explained in Section 3 below. Cell 2, which has a total area of approximately 270,624 sm2, has been filled and covered with interim cover. This cell is comprised of one region, an interim soil cover of varying thickness, which requires . NESHAPs radon flux monitoring. There were no apparent exposed tailings within Cell 2 at during the March 2014 sampling. l Cell 3, which has a total area of approximately 288,858 m2, is nearly filled with tailings sand and is undergoing pre-closure activities. This cell is comprised of two source regions that require NESHAPs radon monitoring: a soil cover region of varying thickness and an exposed tailings "beaches" region. The remaining area is covered by standing liquid in lower elevation areas. 3. REGULATORY REQUIREMENTS FOR THE SITE Radon emissions from the uranium mill tailings at this site are regulated by the State of Utah's Division of Radiation Control and administered by the Utah Division of Air Quality under generally applicable standards set by the Environmental Protection Agency (EPA) for Operating Mills. Applicable regulations are specified in 40 CFR Part 61, Subpart W, National Emission Standards for Radon Emissions from Operating Mill Tailings, with technical procedures in Appendix B. At present, there are no Subpart T uranium mill tailings at this site. These regulations are a subset of the NESHAPs. According to subsection 61.252 Standard, (a) radon-222 emissions to ambient air from an existing uranium mill tailings pile shall not exceed an average of 20 pCi/m2-s for each pile (or cell). Subsection 61.253, Determining Compliance, states that: "Compliance with the emission standard in this subpart shall be determined annually through the use of Method 115 of Appendix B." Cell 1 is completely covered with standing liquid and therefore no radon flux measurements are required on Cell 1. The repaired Cell 4A, and newly constructed Cell 4B, were both constructed after December 15, 1989 and each was constructed with less than 40 acres surface area. Cell 4A and 4B comply with the requirements of 40 CFR 61.252(b), therefore no radon flux measurements are required on either Cell 4A or 4B. 4. SAMPLING METHODOLOGY Radon emissions were measured using Large Area Activated Charcoal Canisters (canisters) in conformance with 40 CFR, Part 61, Appendix B, Method 115, Restrictions to Radon Flux Measurements, (EPA, 2012). These are passive gas adsorption sampling devices used to determine the flux rate of radon-222 gas from a surface. The canisters were constructed using a 10-inch diameter PVC end cap containing a bed of 180 grams of activated, granular charcoal. The prepared charcoal was placed in the canisters on a support grid on top of a Vi inch thick layer of foam and secured with a retaining ring under YA inches of foam (see Figure 1, page 10). One hundred sampling locations were distributed throughout Cell 2 (consisting of one region) as depicted on the Sample Locations Map (see Figure 2, Appendix D). Each charged canister was placed directly onto the surface (open face down) and exposed to the surface for 24 hours. Radon gas adsorbed onto the charcoal and the subsequent radioactive decay of the entrained radon resulted in radioactive lead-214 and bismuth-214. These radon progeny isotopes emit characteristic gamma photons that can be detected through gamma spectroscopy. The original total activity of the adsorbed radon was calculated from these gamma ray measurements using calibration factors derived from cross-calibration of standard sources containing known total activities of radium-226 with geometry identical to the counted samples and from the principles of radioactive decay. After approximately 24 hours, the exposed charcoal was transferred to a sealed plastic sample container (to prevent radon loss and/or further exposure during transport), identified and labeled, and transported to the Tellco laboratory in Grand Junction, Colorado for analysis. Upon completion of on- site activities, the field equipment was alpha and beta-gamma scanned by Energy Fuels Radiation Safety personnel for possible contamination resulting from fieldwork activities. All of the field 2 equipment used was subsequently released for unrestricted use. Tellco personnel maintained custody of the samples from collection through analysis. 5. FIELD OPERATIONS 5.1 Equipment Preparation All charcoal was dried at 110°C before use in the field. Unused charcoal and recycled charcoal were treated the same. 180-gram aliquots of dried charcoal were weighed and placed in sample containers. Proper balance operation was verified daily by checking a standard weight. The balance readout agreed with the known standard weight to within ±0.1 percent. After acceptable balance check, empty containers were individually placed on the balance and the scale was re-zeroed with the container on the balance. Unexposed and dried charcoal was carefully added to the container until the readout registered 180 grams. The lid was immediately placed on the container and sealed with plastic tape. The balance was checked for readout drift between readings. Sealed containers with unexposed charcoal were placed individually in the shielded counting well, with the bottom of the container centered over the detector, and the background count rate was documented. Three five-minute background counts were conducted on ten percent of the containers, selected at random to represent the "batch". If the background counts were too high to achieve an acceptable lower limit of detection (LLD), the entire charcoal batch was labeled non-conforming and recycled through the heating/drying process. 5.2 Sample Locations, Identification, and Placement On March 26, 2014, 100 sampling locations were spread out throughout the Cell 2 covered region. The same sampling locations that were established for previous samplings of Cell 2 were used for the placement of the canisters for March 2014, although the actual sample identification numbers (IDs) may be different. An individual ID was assigned to each sample point, using a sequential alphanumeric system indicating the charcoal batch and physical location within the region (e.g., E01...E100). This ID was written on an adhesive label and affixed to the top of the canister. The sample ID, date, and time of placement were recorded on the radon flux measurements data sheets for the set of one hundred measurements. Prior to placing a canister at each sample location, the retaining ring, screen, and foam pad of each canister were removed to expose the charcoal support grid. A pre-measured charcoal charge was selected from a batch, opened and distributed evenly across the support grid. The canister was then reassembled and placed face down on the surface at each sampling location. Care was exercised not to push the device into the soil surface. The canister rim was "sealed" to the surface using a berm of local borrow material. Five canisters (blanks) were similarly processed and the canisters were kept inside an airtight plastic bag during the 24-hour testing period. 3 5.3 Sample Retrieval On March 27, 2014 at the end of the 24-hour testing period, all canisters were retrieved, disassembled and each charcoal sample was individually poured through a funnel into a container. Identification numbers were transferred to the appropriate container, which was sealed and placed in a box for transport. Retrieval date and time were recorded on the same data sheets as the sample placement information. The blank samples were similarly processed. All 100 charcoal samples from Cell 2 covered region were successfully retrieved and containerized during the retrieval and unloading process. Tellco personnel maintained custody of the samples from collection through lab analysis. 5.4 Environmental Conditions A rain gauge and thermometer were placed within Cell 2 to monitor rainfall and air temperatures during sampling in order to ensure compliance with the regulatory measurement criteria. In accordance with 40 CFR, Part 61, Appendix B, Method 115: • Measurements were not initiated within 24 hours of rainfall. • There was no rainfall after the placement of the canisters. • The criteria regarding minimum ambient air temperature and frozen ground do not apply when performing sampling on a monthly basis; however, the minimum air temperature during the sampling period was 35 degrees F, and the ground was not frozen at any of the sample locations. 6. SAMPLE ANALYSIS 6.1 Apparatus Apparatus used for the analysis: • Single- or multi-channel pulse height analysis system, Ludlum Model 2200 with a Teledyne 3" x 3" sodium iodide, thallium-activated (Nal(Tl)) detector. • Lead shielded counting well approximately 40 cm deep with 5-cm thick lead walls and a 7- cm thick base and 5 cm thick top. • National Institute of Standards and Technology (NIST) traceable aqueous solution radium- 226 absorbed onto 180 grams of activated charcoal. • Ohaus Model C501 balance with 0.1-gram sensitivity. 4 6.2 Sample Inspection and Documentation Once in the laboratory, the integrity of each charcoal container was verified by visual inspection of the plastic container. Laboratory personnel checked for damaged or unsealed containers and verified that the data sheet was complete. All of the 100 sample containers and 5 blank containers received and inspected at the Tellco analytical laboratory were ultimately verified as valid and no damaged or unsealed containers were observed. 6.3 Background and Sample Counting The gamma ray counting system was checked daily, including background and radium-226 source measurements prior to and after each counting session. Based on calibration statistics, using two sources with known radium-226 content, background and source control limits were established for each Ludlum/Teledyne counting system with shielded well (see Appendix A). Gamma ray counting of exposed charcoal samples included the following steps: • The length of count time was determined by the activity of the sample being analyzed, according to a data quality objective of a minimum of 1,000 accrued counts for any given sample. • The sample container was centered on the Nal detector and the shielded well door was closed. • The sample was counted over a determined count length and then the mid-sample count time, date, and gross counts were documented on the radon flux measurements data sheet and used in the calculations. • The above steps were repeated for each exposed charcoal sample. • Approximately 10 percent of the containers counted were selected for recounting. These containers were recounted on the next day following the original count. 7. QUALITY CONTROL (QC) AND DATA VALIDATION Charcoal flux measurement QC samples included the following intra-laboratory analytical frequency objectives: • Blanks, 5 percent, and • Recounts, 10 percent All sample data were subjected to validation protocols that included assessments of sensitivity, precision, accuracy, and completeness. All method-required data quality objectives (EPA, 2013) were attained. 5 7.1 Sensitivity A total of five blanks were analyzed by measuring the radon progeny activity in samples subjected to all aspects of the measurement process, excepting exposure to the source region. These blank sample measurements comprised approximately 5 percent of the field measurements. Analysis of the five blank samples measured radon flux rates ranging from approximately 0.08 to 0.14 pCi/m2-s, with an average of approximately 0.10 pCi/m2-s. The lower limit of detection (LLD) was approximately 0.03 pCi/m2-s. 7.2 Precision Ten recount measurements, distributed throughout the sample set, were performed by replicating analyses of individual field samples (see Appendix B). These recount measurements comprised approximately 10 percent of the total number of samples analyzed. The precision of all recount measurements, expressed as relative percent difference (RPD), ranged from less than 0.1 percent to 9.5 percent with an overall average precision of approximately 4.3 percent RPD. 7.3 Accuracy Accuracy of field measurements was assessed daily by counting two laboratory control samples with known Ra-226 content. Accuracy of these lab control sample measurements, expressed as percent bias, ranged from approximately -1.5 percent to +0.5 percent. The arithmetic average bias of the lab control sample measurements was approximately -0.6 percent (see Appendix A). 7.4 Completeness All 100 of the samples from the Cell 2 cover region were verified, representing 100 percent completeness. 8. CALCULATIONS Radon flux rates were calculated for charcoal collection samples using calibration factors derived from cross-calibration to sources with known total activity with identical geometry as the charcoal containers. A yield efficiency factor was used to calculate the total activity of the sample charcoal containers. Individual field sample result values presented were not reduced by the results of the field blank analyses. In practice, radon flux rates were calculated by a database computer program. The algorithms utilized by the data base program were as follows: Equation 8.1: , N pCi Rn-222/m sec = rrs*A*b*0.5(d/91-75>] 6 where: N = net sample count rate, cpm under 220-662 keV peak Ts = sample duration, seconds b = instrument calibration factor, cpm per pCi; values used: 0.1699, for M-01/D-21 and 0.1702, for M-02/D-20 d = decay time, elapsed hours between sample mid-time and count mid-time A = area of the canister, m2 Equation 8.2: V Sample Count,t,min Background Count,t,min Error,2cr = 2 x x Sample Concent rat ion Net,cpm Gross Sample, cpm Background Sample,cpm + Equation 8.3: 2.71+(4.65)(Sb) LLU" [Ts*A*b*0.5(d/917 where: 2.71 = constant 4.65 = confidence interval factor Sb = standard deviation of the background count rate Ts = sample duration, seconds b = instrument calibration factor, cpm per pCi; values used: 0.1699, for M-01/D-21 and 0.1702, for M-02/D-20 d = decay time, elapsed hours between sample mid-time and count mid-time A = area of the canister, m2 9. RESULTS 9.1 Mean Radon Flux Referencing 40 CFR, Part 61, Subpart W, Appendix B, Method 115 - Monitoring for Radon-222 Emissions, Subsection 2.1.7 - Calculations, "the mean radon flux for each region of the pile and for the total pile shall be calculated and reported as follows: (a) The individual radon flux calculations shall be made as provided in Appendix A EPA 86(1). The mean radon flux for each region of the pile shall be calculated by summing all individual flux measurements for the region and dividing by the total number of flux measurements for the region. (b) The mean radon flux for the total uranium mill tailings pile shall be calculated as follows: JiA, + ... hA7 r+1 ... JiAi Js = At Where: Js = Mean flux for the total pile (pCi/m2-s) Ji = Mean flux measured in region i (pCi/m2-s) A; = Area of region i (m2) At = Total area of the pile (m2)" 7 40 CFR 61, Subpart W, Appendix B, Method 115, Subsection 2.1.8, Reporting states "The results of individual flux measurements, the approximate locations on the pile, and the mean radon flux for each region and the mean radon flux for the total stack [pile] shall be included in the emission test report. Any condition or unusual event that occurred during the measurements that could significantly affect the results should be reported." 9.2 Site Results Site Specific Sample Results (reference Appendix C) (a) The mean radon flux for the Cell 2 region at the site is as follows: Cell 2 - Cover Region = 16.4 pCi/m2-s (based on 270,624 m2 area) Note: Reference Appendix C of this report for the entire summary of individual measurement results, (b) Using the data presented above, the calculated mean radon flux for Cell 2 is as follows: Cell 2= 16.4 pCi/m2-s (16.4V270.624) = 16.4 270,624 As shown above, the arithmetic mean radon flux of the samples for Cell 2 at Energy Fuels White Mesa milling facility is below the NRC and EPA standard of 20 pCi/m2-s. The March 2014 sampling results for Cell 2 are higher than last month's results. Appendix C presents the summary of individual measurement results, including blank sample analysis. Sample locations are depicted on Figure 2, which is included in Appendix D. The map was produced by Tellco. 8 References U. S. Environmental Protection Agency, Radon Flux Measurements on Gardinier and Royster Phosphogypsum Piles Near Tampa and Mulberry, Florida, EPA 520/5-85-029, NTIS #PB86- 161874, January 1986. U. S. Environmental Protection Agency, Title 40, Code of Federal Regulations, July 2013. U. S. Nuclear Regulatory Commission, Radiological Effluent and Environmental Monitoring at Uranium Mills, Regulatory Guide 4.14, April 1980. U. S. Nuclear Regulatory Commission, Title 10, Code of Federal Regulations, Part 40, Appendix A, January 2013. 9 Figure 1 Large Area Activated Charcoal Canisters Diagram 2-HI Tin.;* C^a'CUd- I in Tn^rlL I.-4 in went Hale ftsrabOtfi Pa a rtaMinw z&**Jittfrvlf>*> aw "MS r fTii I Ll i i i: ,1 rvc tna cap [JgUgt 1 Larse-Arta Radon Collector 10 Appendix A Charcoal Canister Analyses Support Documents A ACCURACY APPRAISAL TABLE MARCH 2014 SAMPLING ENERGY FUELS RESOURCES WHITE MESA MILL, BLANDING, UTAH 2014 NESHAPs RADON FLUX MEASUREMENTS CELL 2 SAMPLING DATES: 3/26/14-3/27/14 SYSTEM I.D. DATE Bkg Counts (1 min. each) #1 #2 #3 Source Counts (1 min. each) #1 #2 #3 AVG NET cpm YIELD cpm/pCi FOUND pCi SOURCE ID KNOWN pCi M-01/D-21 3/28/2014 130 131 150 9999 10231 10083 9967 0.1699 58666 GS-04 59300 M-01/D-21 3/28/2014 116 137 145 10070 10126 10084 9961 0.1699 58627 GS-04 59300 M-01/D-21 3/29/2014 148 146 111 10038 10223 10162 10006 0.1699 58893 GS-04 59300 M-01/D-21 3/29/2014 124 138 113 10240 10318 10196 10126 0.1699 59602 GS-04 59300 M-01/D-21 3/28/2014 130 131 150 10096 10129 10065 9960 0.1699 58621 GS-05 59300 M-01/D-21 3/28/2014 116 137 145 10195 10209 10272 10093 0.1699 59404 GS-05 59300 M-01/D-21 3/29/2014 148 146 111 10083 10101 9998 9926 0.1699 58421 GS-05 59300 M-01/D-21 3/29/2014 124 138 113 10293 10164 10136 10073 0.1699 59286 GS-05 59300 M-02/D-20 3/28/2014 146 145 133 10291 10064 10138 10023 0.1702 58890 GS-04 59300 M-02/D-20 3/28/2014 126 135 141 10435 10162 10219 10138 0.1702 59565 GS-04 59300 M-02/D-20 3/29/2014 128 142 126 10062 10163 10240 10023 0.1702 58890 GS-04 59300 M-02/D-20 3/29/2014 123 144 112 10284 10136 10228 10090 0.1702 59281 GS-04 59300 M-02/D-20 3/28/2014 146 145 133 10182 10216 10057 10010 0.1702 58815 GS-05 59300 M-02/D-20 3/28/2014 126 135 141 10189 10123 10122 10011 0.1702 58817 GS-05 59300 M-02/D-20 3/29/2014 128 142 126 10322 10139 9999 10021 0.1702 58880 GS-05 59300 M-02/D-20 3/29/2014 123 144 112 10158 10074 10144 9999 0.1702 58749 GS-05 59300 AVERAGE PERCENT BIAS FOR ALL ANALYTICAL SESSIONS: -0.6% CHARCOAL CANISTER ANALYSIS SYSTEM SITE LOCATION: £.W^^y ^WjyQ *<TC*-$ CLIENT. NA/V^-W- K*^I vV» W} • b Calibration Check Log System ID: Calibration Date: Due Date: Scaler S/N: D IS"7 Detector S/N: _ High Voltage: I t?Xt> Window: 4.42 Thrshld: 2.20 Source ID/SN: ^ Source Activity: Blank Canister Bkgd. Range, cpm: 2 o = ffG to j t> ^ 3a = to rTJ Gross Source Range, cpm: 2 o = °|62 3 to I OS ^ 7 3 o = 9)G?H Z to jO^J 2. g Technician: All counts times are one minute. Date By Background Counts (1 min #1 #2 #3 each) Avg. Source Counts (1 min. each) #1 #2 #3 Average •age ok? Y/N 5 4 £32. 137 \Q£2S2> {Ol ILk i3H m. I0«7C> »1 MS r0llo-2 \ \3&. 113. AS L02±LQ. 1C!3_LS. Y/N: Y = average background and source cpm falls within the control limits. N = average background and source cpm does not fall within the control limits. The acceptable ranges were determined from prior background and source check data. CHARCOAL CANISTER ANALYSIS SYSTEM SITE LOCATION. Urfc Mffrfr \k\\[) ^1*1/1^ ^ ,014* k Calibration Check Log CLIENT: System ID: \A ' ° * ) X) ~ % 1 Calibration Date: jg ^ * H ( '3 Due Date: ' T Scaler S/N: 5" < 5 7 Z- High Voltage: lO 'ZS Window: 4.42 Thrshld: 2.20 Detector S/N: O *-{ < S 3 3 Source ID/SN: ^fl"** S ~Q ^ Source Activity: ^^.3 K p £t Blank Canister Bkgd. Range, cpm: 2 o = to I 5" *4 3 a = ^ ^ to 1~? | Gross Source Range, cpm: 2 c = Gj(S>°)S' to ) O S 1 ^ 3 a = °)1 <A g to |Ok>7 / Technician: All counts times are one minute. Date By Background Counts (1 min #1 #2 #3 each) Avg. #1 Source Counts (1 min. each) #2 #3 Average ok? Y/N 3 l£0_ J<LO IP 12^ 77 33 US. 13 L3£ IQQ33-\o ioi SQ3fi \%5 10^3 Y/N: Y = average background and source cpm falls within the control limits. N = average background and source cpm does not fall within the control limits. The acceptable ranges were determined from prior background and source check data. CHARCOAL CANISTER ANALYSIS SYSTEM SITE LOCATION: W ftg&fl lAU\} 1cU >^ jU+lk CLIENT: Efur^y ^Wls ^eirt?CifCg<, (jK 6 4) Calibration Check Log System ID: fvVO?. /V^O Calibration Date: ^/[j/ £j Due Date: b / / Scaler S/N: S 1 f? l/»3 High Voltage: f Q~7S Window: 4.42 Thrshld: 2.20 Detector S/N: 0 H j *D 3 Source ID/SN: RO^^/GS'° *j Source Activity: 5^.3 K p£ j Blank Canister Bkgd. Range, cpm: 2 a = "7 {3 to I S ) 3<J= fe> Cj to I"7 O Gross Source Range, cpm: Technician: se^^L ^hfi^ g All counts times are one minute. Post Date By Background Counts (1 min. each) #1 #2 #3 Avg. #1 Source Counts (1 min. each) #2 #3 Average ok? Y/N if J4l 10 q°) ± io 1 U,3 ^3. im. Y/N: Y = average background and source cpm falls within the control limits. N = average background and source cpm does not fall within the control limits. The acceptable ranges were determined from prior background and source check data. CHARCOAL CANISTER ANALYSIS SYSTEM CSITE LOCATION: £.f1e^y gjtgj| *r^5*>it/N^S £^5>/f) CLIENT: \fj UUe, Kti^ pV%\\ ; BUttci* ^ , Calibration Check Log SystemID: V\ ~ P 2,T> ~ 2.Q Calibration Date: CfJ_ 1 H / /3 Due Date: 6/ / <y / ( Scaler S/N: S' S ^ 3 High Voltage: j^jj S Window: 4.42 Thrshld: 2.20 Detector S/N: ° *"T I b 3 Source ID/SN: ^c7"^/2?S ' OS Source Activity: S j j 3 fcp £ > Blank Canister Bkgd. Range, cpm: 2 o = "7 'S to I 3 I 3o= 0>O to 1 7 jg Gross Source Range, cpm: 2 o = ^ 84^ to 1 C?4 °) 6 3 o = °) (o 8 3 to ( 0- I Technician: >\y? / — ^&t^ All counts times are one minute. Date By Background Counts (1 min. each) #1 #2 #3 Avg. #1 Source Counts (1 min. each) #2 #3 Average ok? Y/N 13_3 Si IS tQa.i \o\-z-XL. X23. 2XL 10 07^ Y/N: Y = average background and source cpm falls within the control limits. N = average background and source cpm does not fall within the control limits. The acceptable ranges were determined from prior background and source check data. BALANCE OPERATION DAILY CHECK Balance Model: OUAUS ?Q f4 - p - ^ Shi [ 2-3 & 7 Standard Weight (g): XP^ O Date Pre-check (g) 2. O0»0 Post-check (g) O.K. ± 0.1 % ? By Appendix B Recount Data Analy: B CLIENT: ENERGY FUELS RESOURCES PROJECT: RADON FLUX MEASUREMENTS, WHITE MESA MILL PROJECT NO: 14004.03 PILE: 2 BATCH: E SURFACE: SOIL AREA: COVER DEPLOYED: 3 26 14 RETRIEVED: 3 FIELD TECHNICIANS: MC,DLC, CS, TE COUNTED BY: DLC COUNTING SYSTEM I.D.: M01/D21, M02/D20 CAL. DUE: 6/14/14 AIR TEMP MIN: 35°F 27 14 CHARCOALBKG: DATA ENTRY BY: DLC WEATHER: CLEAR 148 cpm Wt. Out: 180.0 g. TARE WEIGHT: 29.2 g. RECOUNT CANISTER ANALYSIS: GRID XJ C JVX* X (DI1? E10 RECOUNT E20 RECOUNT E30 RECOUNT E4 0 RECOUNT E50 RECOUNT E60 RECOUNT E70 RECOUNT E80 RECOUNT E90 RECOUNT E100 RECOUNT SAMPLE I. D. E10 ElO E20 E2 0 E30 E30 E40 E40 E60 E60 E90 E90 ElOO ElOO IV ANALYSIS MID-TIME HR MIN HR MIN MO DA YR HR MIN (MIN) COUNTS 10 17 10 19 3 28 14 13 44 1 12028 10 17 10 19 3 29 14 12 50 1 10747 10 34 10 34 10 18 10 18 10 10 10 10 10 10 10 10 24 24 25 25 15 15 28 14 29 14 13 12 3 28 14 14 3 29 14 12 3 28 14 3 29 14 14 12 52 50 2 52 10 52 21150 17522 11611 10139 1611 1306 WT IN pCi/m2s pCi/m2s pCi/m2s 222 . 222 . 218 . 218 . 217 . 0 217 . 0 216 , 216 . 10 34 10 34 10 10 34 34 3 28 14 3 29 14 14 12 29 54 12560 10381 215 . 9 215 . 9 10 10 10 10 46 46 52 52 10 10 10 10 37 37 37 37 28 14 14 29 14 12 28 29 14 14 15 12 54 58 5 58 2594 2373 1504 1264 220 . 3 220.3 218 , 218 . 20.7 22 . 0 36 . 8 36 . 2 19 20 1. 1. E50 10 17 10 24 3 28 14 14 21 2 1764 216.3 1.3 E50 10 17 10 24 3 29 14 12 54 2 1494 216.3 1.2 21.7 21.2 E70 10 48 10 29 3 28 14 14 36 1 4332 215.0 7.4 E70 10 48 10 29 3 29 14 12 57 1 3614 215.0 7.3 E80 10 41 10 31 3 28 14 14 46 1 1264 217.5 2.0 E80 10 41 10 31 3 29 14 12 57 1 1129 217.5 2.0 4 . 3 4 . 6 0.4 0.5 0 . 03 0 . 04 0 . 03 0 . 04 0 . 03 0 . 04 0 . 03 0 . 04 0 . 03 0 . 04 2.2 0.03 2.1 0.04 0 . 03 0 . 04 0 . 03 0 . 04 0 . 03 0 . 04 0 . 03 0 . 04 6.1% 1.61 3 .51 9.51 8.0% 2.3% 1.41 0 . 01 6 . 7% 4.31 AVERAGE PERCENT PRECISION FOR THE CELL 2 COVER REGION: 4.3% Page 1 of 1 Appendix C Radon Flux Sample Laboratory Data (including Blanks) c CLIENT: ENERGY FUELS RESOURCES PROJECT: RADON FLUX MEASUREMENTS, WHITE MESA MILL PROJECT NO: 14004.03 PILE: 2 BATCH: E SURFACE: SOIL AREA: COVER DEPLOYED: 3 26 14 RETRIEVED: 3 FIELD TECHNICIANS: MC.DLC, CS, TE COUNTED BY: DLC COUNTING SYSTEM I.D.: M01/D21, M02/D20 CAL. DUE: 6/14/14 AIR TEMP MIN: 35°F 27 14 CHARCOAL BKG: DATA ENTRY BY: DLC WEATHER: CLEAR 148 cpm WtOut: 180.0 g. TARE WEIGHT: 29.2 g. GRID LOCATION E01 E02 E03 E04 E05 E06 E07 E08 E09 E10 Ell E12 E13 E14 E15 E16 E17 E18 E19 E20 E21 E22 E23 E24 E25 E26 E27 E28 E29 E30 E31 E32 E33 E34 E35 E36 E37 SAMPLE E01 E02 E03 E04 E05 E06 E07 E08 E09 E10 Ell E12 E13 E14 E15 E16 E17 E18 E19 E2 0 E21 E22 E23 E24 E25 E26 E2 7 E2 8 E2 9 E3 0 E31 E32 E33 E34 E35 E36 E37 DEPLOY RETRIV ANALYSIS HR MIN HR MIN MO DA YR MID-TIME HR MIN 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 2 3 5 7 8 10 11 14 15 17 18 20 21 24 25 27 28 29 31 34 34 31 29 28 27 25 24 21 20 18 17 15 14 11 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 15 15 16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23 24 24 28 28 28 27 27 27 26 26 26 25 24 24 23 22 22 21 19 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 13 13 13 13 14 13 14 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 38 38 39 39 41 41 43 43 44 44 46 46 47 47 49 49 50 50 52 52 53 53 55 55 57 58 0 0 2 2 3 3 5 5 6 6 CNT (MIN) 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 GROSS COUNTS 1599 1289 2112 13943 1613 1522 1490 10579 1224 12028 13665 34415 18791 6710 3241 1311 7345 26269 11947 21150 8152 14738 4617 9285 5956 1154 15919 5251 3076 11611 21615 13172 5894 3952 18478 24199 10135 GROSS WT IN RADON + LLD pCi/m*s pCi/m2s pCi/m2s COMMENTS: 217 , 215 . 218 . 218 . 223 . 0 215 . 9 216 . 8 222 . 3 216 . 8 222 . 5 217.7 214 .2 224 . 2 222 .4 217.9 220.8 216 . 7 216.5 217 . 8 218.6 220 .4 214 . 7 215 . 3 223 . 8 215 . 218 . 221. 216 . 213 . 217 . 0 219 . 2 219.3 215 . 7 218.8 222 . 7 221 . 5 217 . 6 2 . 5 2 . 0 3.4 23 . 9 1 . 1 1.1 2 . 3 18 1. 20 . 23 . 59 . 7 .5 .4 .4 .0 .6 .7 , 7 32 . 11. 5 , 2 . 12 . 45 . 20 . 36 . 8 14 . 0 25.5 7 . 8 15 . 9 10 . 1 0 . 27 . 5 . 19. 37. 22 . 10 . 0 6.6 31 . 8 41. 6 17 . 3 0 . 3 0.2 0 . 3 2.4 0 .1 1 2 8 2 1 4 0 3 1 5 2 3 6 1 7 4 5 8 6 0 1 8 9 5 0 7 2.3 1.0 0 . 7 3.2 4.2 1 . 7 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0.03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 Page 1 of 3 CLIENT: ENERGY FUELS RESOURCES PROJECT: RADON FLUX MEASUREMENTS, WHITE MESA MILL PROJECT NO: 14004.03 PILE: 2 BATCH: E SURFACE: SOIL AREA: COVER DEPLOYED: 3 26 14 RETRIEVED: 3 FIELD TECHNICIANS: MC.DLC, CS, TE COUNTED BY: DLC COUNTING SYSTEM I.D.: M01/D21, M02/D20 CAL. DUE: 6/14/14 AIR TEMP MIN: 35°F 27 14 CHARCOAL BKG: DATA ENTRY BY: DLC WEATHER: CLEAR 148 cpm Wt. Out: 180.0 g. TARE WEIGHT: 29.2 g. GRID LOCATION E38 E3 9 E40 E41 E42 E43 E44 E45 E46 E47 E4 8 E49 E50 E51 E52 E53 E54 E55 E56 E57 E58 E59 E60 E61 E62 E63 E64 E65 E66 E67 E68 E69 E70 E71 E72 E73 E74 SAMPLE I. D. E38 E39 E40 E41 E42 E43 E44 E45 E46 E47 E4 8 E49 E50 E51 E52 E53 E54 E55 E56 E57 E58 E59 E60 E61 E62 E63 E64 E65 E66 E67 E68 E69 E70 E71 E72 E73 E74 DEPLOY RETRIV ANALYSIS MID-TIME HR MIN HR MIN MO DA YR HR MIN 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 5 3 2 2 3 5 7 8 10 11 14 15 17 18 20 21 24 25 27 28 29 31 34 36 38 39 41 42 44 45 46 47 48 49 50 51 52 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 18 16 15 15 16 18 19 21 22 22 23 24 24 25 26 26 27 28 30 31 33 34 34 25 25 26 26 27 27 28 28 29 29 30 30 31 31 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 8 9 10 12 13 15 15 17 17 18 18 20 21 23 23 24 24 26 26 27 27 29 29 30 30 32 32 33 33 35 35 36 36 38 38 39 39 CNT (MIN) 1 1 2 1 2 2 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 GROSS COUNTS 1016 9934 1611 2180 1608 1181 52536 79338 4363 26146 31892 3288 1764 8446 8574 4900 13678 1916 22331 24329 10273 5297 12560 4221 3232 2653 58966 7720 5149 43662 2418 3803 4332 16220 14200 6132 8853 .9 . 1 .2 . 8 GROSS WT IN 215 .1 216 .4 216.7 217.4 217.7 220 . 8 224 . 6 224 . 5 218 , 232 222 217 216 . 3 221 .4 223 . 5 220 .3 221 . 9 221 . 5 216 . 1 221.2 216 .2 216 . 0 215 . 214 . 218 . 217 . 220 . 217 . 216 . 215 . 8 219.6 219.7 215.0 219 . 3 216 .4 208.3 213 . 0 RADON pCi/m2s pCi/ir^s pCi/m2s COMMENTS: 9 5 1 , 1 .1 ,1 .4 1 . 5 17 . 0 1. 1 3.5 1.1 0 . 8 90 . 9 137 . 5 7.3 45 . 55 . 5 . 1 . 14 . 14 . 7 8 . 3 23 . 3 . 38 . 42 . 17 .7 9 21 7 5 4 103 13 77 . 1 4 . 0 6 . 5 7.4 28 . 5 24 . 9 10 . 6 15 .4 0.2 1 . 7 0 . 1 0.4 0 . 1 0 .1 9 . 1 13 . 8 0 . 7 4 . 5 5 . 5 0 . 5 0 .1 1.4 1 . 5 0.8 2.4 0. 3 3 . 9 4.2 1. 8 0. 2 0 . 0 . 0 10 1. 0 7 0 0 0 2 2. 1 1 0 . 03 0 . 03 0. 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 Page 2 of 3 CLIENT: ENERGY FUELS RESOURCES PROJECT: RADON FLUX MEASUREMENTS, WHITE MESA MILL PROJECT NO: 14004.03 PILE: 2 BATCH: E SURFACE: SOIL AREA: COVER DEPLOYED: 3 26 14 RETRIEVED: 3 FIELD TECHNICIANS: MC,DLC, CS, TE COUNTED BY: DLC COUNTING SYSTEM I.D.: M01/D21, M02/D20 CAL. DUE: 6/14/14 AIR TEMP MIN: 35°F 27 14 CHARCOALBKG: DATA ENTRY BY: DLC WEATHER: CLEAR 148 cpm Wt. Out: 180.0 g. TARE WEIGHT: 29.2 g. GRID LOCATION E75 E76 E77 E78 E79 E80 E81 E82 E83 E84 E85 E86 E87 E88 E89 E90 E91 E92 E93 E94 E95 E96 E97 E98 E99 ElOO SAMPLE DEPLOY RETRIV ANALYSIS MID-TIME CNT GROSS GROSS RADON + LLD I. D. HR MIN HR MIN MO DA YR HR MIN (MIN) COUNTS WT IN pCi/m2S pCi/m2s pCi/m2s COMMENTS: E75 E76 E77 E78 E79 E80 E81 E82 E83 E84 E85 E86 E87 E88 E89 E90 E91 E92 E93 E94 E95 E96 E97 E98 E99 ElOO 10 53 10 10 54 10 10 36 10 10 38 10 10 39 10 10 41 10 10 42 10 10 44 10 10 45 10 10 46 10 10 48 10 10 49 10 10 51 10 10 52 10 10 48 10 10 46 10 10 45 10 10 44 10 10 42 10 10 41 10 10 39 10 10 38 10 10 36 10 10 50 10 10 51 10 10 52 10 32 32 30 30 30 31 31 31 32 32 32 33 33 33 37 37 37 36 36 36 35 35 35 36 36 37 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 28 28 28 14 14 14 28 14 28 14 28 28 28 28 28 28 14 14 14 14 14 14 28 14 28 14 28 14 28 14 28 28 28 28 28 28 28 28 28 28 28 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 15 15 15 15 15 41 41 43 43 46 46 48 48 49 49 51 51 52 52 54 54 55 55 57 57 59 0 3 3 6 5 1 1703 1 1390 3 1186 2 1376 1 1291 1 1264 1 1841 1 8304 1 6416 1 1738 1 3112 1 6567 1 2471 1 8302 1 10077 1 2594 1 1673 1 5424 1 4843 1 1185 2 1414 4 1189 1 1404 1 2446 2 1528 1 1504 217.5 217 .4 213 .5 215 . 7 220.8 217 . 5 216.1 219 . 0 222 . 8 218 . 218 . 221. 216 , 218 , 221 . 220 . 219 , 222 , 218 . 219 . 0 225 . 0 216 .2 219 . 1 220.9 221.8 218.6 2 2 0 1 2 2 3 14 11 2 . 5 . 11 4 . 14 17 4 . 2 . 9 8 1 . 1. 0. 2 4 1 2 0 . 3 0 . 2 0 . 0 0.8 0.2 0 . 1 0 . 0 0.2 0.4 0.1 0.2 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 AVERAGE RADON FLUX RATE FOR THE CELL 2 COVER REGION: 16 .4 BLANK CANISTER ANALYSIS: GRID LOCATION E BLANK 1 E BLANK 2 E BLANK 3 E BLANK 4 E BLANK 5 SAMPLI E BLANK E BLANK E BLANK E BLANK RETRIV ANALYSIS HR MIN HR MIN MO DA YR 0.3 137.5 pCi/m: MIN MAX -TIME CNT GROSS GROSS RADON + HR MIN (MIN) COUNTS WT IN pCi/m2s pCi/m2s pCi/m2s COMMENT E BLANK 5 45 45 45 45 45 10 5 10 5 10 5 10 5 10 5 3 28 14 3 28 14 3 28 14 10 10 10 28 14 10 28 14 11 45 45 56 56 7 10 10 10 10 10 2148 1944 2009 2064 2293 214 . 5 210 . 5 209 . 1 211 .3 209 . 6 0 . 11 0 . 08 0 . 09 0 . 10 0 . 14 0 . 02 0 . 02 0 . 02 0 . 02 0 . 02 0 . 03 0 . 03 0 . 03 0 . 03 0 . 03 CONTROL CONTROL CONTROL CONTROL CONTROL AVERAGE BLANK CANISTER ANALYSIS FOR THE CELL 2 COVER REGION: wmmmmmmmmmmmmmmmmmmmm^ Page 3 of 3 0 .10 pCi/m2s Appendix D Sample Locations Map (Figure 2) D CELL1~ 71 • -• • 1 CELL -CELL4B- WHITE MESA MILL BLANDING. UTAH NESHAPS 2014 MARCH 2014 SAMPLING 3/26/14-3/27/14 CELL 2 PREPARED FOR ENERGY FUELS RESOURCES £01 O • SAMPLE LOCATION ON COVERED AREAS 3/26/14-3/27/14 FIGURE 2 N \ SCALE IN FEET 200 100 0 200 400 TMCO ENVIRONMENTAL, LLC THIS DRAWING IS THE PROPERTY OF TELLCO ENVIRONMENTAL, LLC, AND IS NOT TO BE REPRODUCED, MODIFIED OR USED FOR ANY OTHER PROJECT OR EXTENSION OF THIS PROJECT EXCEPT BY AGREEMENT WITH TELLCO.