DRC-2024-006456

299 South Main Street, Suite 1700 ▪ Salt Lake City, Utah 84111
[phone] ▪ Fax: [phone] ▪ www.energysolutions.com

August 6, 2024 CD-2024-168

Mr. Doug Hansen, Director
Division of Waste Management and Radiation Control
P.O. Box 144880
Salt Lake City, UT 84114-4880

Re: Response to DRC-2024-006260 Request for Information (RFI) to the LLRW & 11e.(2)
CQA/QC Manual Specification 148 A, Radon Barrier Thickness; Request for Variance to
Verify Lift Thickness Using GPS Equipment Radioactive Material License Number
UT2300249

Dear Mr. Hansen:

EnergySolutions hereby responds to a Request for Information received from the Director of
Waste Management and Radiation Control (DRC-2024-006260) regarding EnergySolutions’ July
16, 2024 Request (via CD-2024-147) to vary with Specification 148, Verify Lift Thickness Using
GPS Equipment of the LLRW & 11e.(2) CQA/QC Manual (revision 28c). Details to (DRC-2024-
006260) and this response were reviewed with the DWMRC staff on July 30, 2024.

DIRECTOR’S REQUEST 2a: Technical specifications have been provided for the Quality
Control (QC) Staff. EnergySolutions’ (via CD-2024-147) described the description of the
equipment being used by the contractor (Broken Arrow) and attached is an email
correspondence describing the Global Positioning System (GPS) tolerances. Due to lack of a
technical data sheets for the GPS guided equipment being utilized by the contractor to
support the claims in the initial variance request letter (CD-2024-128), “enhance the
efficiency of the process and the accuracy of the final product”, this response to the RFI is
inadequate.

EnergySolutions’ Response: The contractor (Broken Arrow) constructing Phase VI of the
Class A West (CAW) Phase VI final cover will be using the following equipment (or
approved equivalent):
1. John Deere 850L Smartgrade Track Dozer equipped with Topcon GR-i3 GNSS
Receiver
2. John Deere 950K Smartgrade Track Dozer equipped with Topcon GR-i3 GNSS
Receiver
3. John Deere 872 GP Smartgrade Motorgrader equipped with Topcon GR-i3 GNSS
Receiver
4. Base Station/Repeater equipped with Topcon Hiper VR GNSS Receiver

Mr. Doug Hansen
August 6, 2024
CD-2024-168
Page 2 of 4

299 South Main Street, Suite 1700 ▪ Salt Lake City, Utah 84111
[phone] ▪ Fax: [phone] ▪ www.energysolutions.com

Tolerances for the GPS guided equipment used by the contractor will be connected to the
Base Station/ Repeater equipped with Topcon Hiper VR GNSS Receiver which are
described in the Technical Specifications (see attached). It should be noted that the John
Deere 850L Smartgrade Track Dozer, John Deere 950K Smartgrade Track Dozer, and
John Deere 872 GP Smartgrade Motorgrader all equipped with the Topcon GR-i3 GNSS
Receivers will communicate with the Base Station/Repeater equipped with Topcon Hiper
VR GNSS Receiver (see attached specifications) with RTK precision and accuracy. The
accuracy of the contractor’s equipment will also be verified by the precision of the
Quality Control Technician GPS equipment and site control point (CP-1) located in the
southwest corner of the site.

DIRECTOR’S REQUEST 2b: EnergySolutions’ responses to Director’s Request 2 from
DRC-2024-006260 are incomplete. The Director requests a detailed description of
methodologies in which the GPS equipment will be used and resulting data (i.e., summary
of precision of each of the equipment, example of how the contractor’s equipment will
maintain grade throughout operation).

EnergySolutions’ Response: The original variance submittal (via CD-2024-128)
requested that the GPS-placement methods should apply to the Radon Barrier, Filter
Zone, Sacrificial Soil and Rock Erosion Barrier layers referenced in Specifications 148,
169, 174, 179, and 184 of the CQA/QC Manual (Revision 28c). EnergySolutions has
decided to limit the requested variance to only apply to the Radon Barrier and Drainage
Ditch (clay) lift thickness placement methods referenced in Specifications 148 and 184.
EnergySolutions proposes to verify lift thickness by using GPS machine control
equipment and the following method during the construction of Phase VI Final Cover on
the Class A West embankment:

1. Method 1: Compare the elevation readings of the QC GPS survey equipment
with those from the elevation set within the contractor’s GPS guided equipment
used for placement, ensuring that the difference between the two does not exceed
0.1 feet. Elevations will be checked at least twice daily (once before placement
and once at mid-day). Additionally, verify the elevation if there is a failure to the
GPS equipment at any point during the day.
a. Control Point Verification: At the start of each day, QC must verify the
accuracy of the QC GPS equipment by surveying Clive’s Control Point
(located in the southwest corner of the facility site, CP-1). The reported
elevation must be within +- 0.1 ft of elevation 4269.758 (NGVD29 Cap
Elevation). This verification will be documented in the Daily
Construction Report.
b. GPS Guided Equipment Verification: QC will then verify the accuracy
of the contractor’s GPS-guided equipment (e.g., dozer or grader) by
comparing the elevation of the equipment's blade with the elevation
reported by the QC Technician’s GPS Rover. The QC Technician will

Mr. Doug Hansen
August 6, 2024
CD-2024-168
Page 3 of 4

299 South Main Street, Suite 1700 ▪ Salt Lake City, Utah 84111
[phone] ▪ Fax: [phone] ▪ www.energysolutions.com

position the GPS Rover at the corner of the blade to record its elevation.
The equipment operator will then note the elevation displayed on their
screen. The two measurements should not differ by more than 0.1 feet.
This verification must be conducted at least twice daily—once prior to
placement begins and every 5 hours of placement for each day.
Additionally, verification should occur if there is any failure to the GPS
equipment at any point during the day. These verifications will be
documented on the Daily Construction Report. The Project Manager
shall be notified of any discrepancies.

DIRECTOR’S REQUEST 3: The response to this RFI is incomplete. It is clear that QC
staff will check material lift thickness at a rate of “5 times per 10,000 ft².” The initial
variance request (CD-2024-128) states, “QC shall verify the initial offset of the GPS equipped
dozer/grader by using the GPS survey equipment or a tape measure.” It is unclear if or when
QC will utilize GPS survey equipment or a tape measure to verify grade at the dozer.
Furthermore, the process outlined in CD-2024-128 does not account for a methodology of
verifying potential error of the GPS unit may have on the earthwork equipment during fill
operation. Should the dozer place material (primarily for material lifts that do not have a
buy-off survey) for a long duration without checking the precision at any point during the
daily operation, there can be consequential error in grade when attempting to verify grade
on the material lift directly above or upon completing the as-built survey at the Top of
Cover.

EnergySolutions’ Response: As mentioned above, EnergySolutions is modifying the
original request to apply only to the Radon Barrier and Drainage Ditch (clay) placement
methods outlined in Specifications 148 and 184. Both methods require buy-off surveys,
as specified in Specifications 153, 159, and 187. The placement methods for the Filter
Zone, Sacrificial Soil, and Rock Erosion Barrier will be reviewed at a later date for
inclusion in the revision of the LLRW & 11e.(2) CQA/QC Manual.

DIRECTOR’S REQUEST 5b: The response to this RFI is incomplete. It is unclear if the
methodologies will be applied for “for each lift constructed in Phase VI of the CAW final
cover” or “to be performed between lifts of radon barrier clays.”

EnergySolutions’ Response: These methodologies will be applied exclusively to the
Radon Barrier placement for the 1 x 10⁻⁶ and 5 x 10⁻⁸ layers, as well as the Drainage
Ditch Imported Borrow placement.

DIRECTOR’S REQUEST 6: The response to this RFI appears to be sufficient; however,
the response omits this statement, “An example Daily Construction Report is attached.” An
example Daily Construction Report does not appear to be attached to this CD-2024-147.

Mr. Doug Hansen
August 6, 2024
CD-2024-168
Page 4 of 4

299 South Main Street, Suite 1700 ▪ Salt Lake City, Utah 84111
[phone] ▪ Fax: [phone] ▪ www.energysolutions.com

Furthermore, the Division will discuss additional expectations prior to proceeding with
Phase VI Cover Construction.

EnergySolutions’ Response: An example Daily Construction Report is attached.

GPS technology is an accepted industry practice for minimizing human error, increasing
placement efficiency, and reducing worker exposure to hazards. Usage of verified GPS guided
equipment has the ability to ensure uniform lift thickness placement. The currently approved
buy-off surveys will continue to be performed on the transition between radon barrier layers with
different specified permeabilities, on the final surface of the radon barrier, and on the final
surface of the drainage ditch to ensure that the radon barriers and drainage ditch layers are placed
within the specified design elevations. Also, the proposed variance will improve the field safety
conditions for the QC Technicians by eliminating the need for the technicians to walk over loose,
slippery surfaces and in proximity with working heavy equipment to place and remove grade
stakes. It should also be noted that if any technical issues or discrepancies should arise regarding
the proposed method that EnergySolutions shall implement the currently approved thickness
verification methods of Specifications 148 and 184 in the CQA/QC Manual for the placement of
radon barrier and drainage ditch.

Should you have any questions regarding this submission please feel free to contact Nick Clarke
at [phone] or myself at [phone].

Sincerely,

For Steve D. Gurr
Environmental Engineer and Manager

enclosures
Digitally signed by Nick Clarke
DN: dc=com, dc=energysolutions, ou=North America, ou=Users,
ou=CLUT, cn=Nick Clarke, email=[e-mail]
Date: 2024.08.06 14:10:43 -06'00'
CL-QC-PR-002-F2
Rev. 0
DAILY CONSTRUCTION REPORT

QC Technician (SIGN & DATE)

QC APPROVAL DATE QA APPROVAL DATE

EnergySolutions
Clive, Utah Page ____ of ____

PROJECT: CAW MW 11e.(2) OTHER Embankment Construction
DATE 8/2/2024
WEATHER: Fair Cloudy Warm Rain Snow Wind OTHER
CONSTRUCTION OPERATIONS: Waste Placement Cell Excavation Clay Liner Radon Barrier
Rock Placement OTHER N/A
PERSONNEL ON SITE: Operations OTHER Broken Arrow

DAILY PROGRESS MEETING: Yes No
LIFTS TESTED: N/A
LIFTS APPROVED: N/A
EXPLANATIONS:
Phase 6:
In the Morning and after Lunch QC verified their GPS (Trimble SPS986) using CP -1 with satisfactory results. QC then perform a GPS
verification on (example John Deere 850K WLT) with placing our GPS on the right corner of the dozer blade. The difference between
Trimble SPS986 and John Deere 850K WLT was satisfactory with less than a .1' deviation .

EXAMPLE