DRC-2024-005438

DRC-2024-005438 195 North 1950 West • Salt Lake City, UT Mailing Address: P.O. Box 144880 • Salt Lake City, UT 84114-4880 Telephone [phone] • Fax [phone] • T.D.D. 711
www.deq.utah.gov Printed on 100% recycled paper
State of Utah
SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor
Department of Environmental Quality
Kimberly D. Shelley Executive Director DIVISION OF WASTE MANAGEMENT AND RADIATION CONTROL Douglas J. Hansen Director
April 25, 2024
Vern C. Rogers, Director of Regulatory Affairs EnergySolutions, LLC 299 South Main Street, Suite 1700
Salt Lake City, UT 84111 RE: Federal Cell Facility Application Request for Information Dear Mr. Rogers: The Division of Waste Management and Radiation Control (Division) hereby provides follow up Requests
for Information (RFI) regarding the Federal Cell Facility Application dated August 4, 2022. Each RFI in the attached document represents a follow up to an RFI issued earlier in the application review process. The numbering system ties the additional questions to the initial RFI with an added letter designation. When responding to an RFI, please use the assigned number representing the question.
With this round of follow up RFIs, the Division recommends that appropriate staff from the Licensee, the Division, and consultants meet to discuss each matter for clarity. Please contact Otis Willoughby at 385-622-2213 to schedule a meeting. Sincerely,
Douglas J. Hansen, Director Division of Waste Management and Radiation Control
DJH/OHW/JMK/jk Enclosure: Federal Cell Application Review, Requests for Info. or Updates to the Application (RFI) c: Jeff Coombs, EHS, Health Officer, Tooele County Health Department
Bryan Slade, Environmental Health Director, Tooele County Health Department EnergySolutions General Correspondence Email LLRW General Correspondence Email

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Federal Cell Application Review

Request for Information or Updates to the Application (RFI) General
• Each of the RFI’s has been assigned an identifier with a numbering convention as follows-
o Application/Appendix Section
 Section/Appendix Subsection
• Section/Appendix Subsubsection (when applicable)
o Sequential numbering
Example: A question in Section 1, subsection 1, subsubsection 1 -The first RFI # would be 1.1.1-1, the next question in that section/subsection would be numbered 1.1.1-2 Please refer to the assigned RFI number when submitting a response.

Appendix O: Federal Cell Facility Waste Characterization Plan

O-40.a NAC-0025 R4 indicates the chemical conditions (high ionic strength) in the saturated zone at Clive are not considered favorable for colloid transport. The Division agrees with the assessment that discussions and assertations regarding colloid facilitated radionuclide migration are complex. However, the
potential influence of colloids and the ionic strength of Clive groundwater needs to be documented. While higher ionic strengths can facilitate aggregation and reduce colloid transport, there are conditions where colloids can move depending on the colloid composition, pH, and presence of counter ions which can reduce aggregations. A summary of previous colloid transport work is included, but the studies are not explicitly compared to the conditions at the Clive site. Thus, more detail is necessary to support the
assumptions presented. Please submit an evaluation of the role of colloid transport in terms related to the specific conditions at the Clive site. O-40.b The following statement is found on Page 9 of NAC-0025 R4: “Using the data from the average of all wells shown in Table 7, the stoichiometric ionic strength is calculated at 0.73 M (mol/L).” It appears
there are some errors in calculating the average values. The ionic strength of 0.73 M matches that for GW-19A with the highest Na+ and Cl- concentrations but is not the stoichiometric ionic strength calculated for all wells shown in Table 7. Please verify the stoichiometric ionic strength calculated for all wells shown in Table 7.

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O-40.c

In section 5.1.9 of NAC-0025 R4, the solubility of radium is reported to be controlled by RaSO4(s) using surrogate values for barite (BaSO4(s)) and as a co-precipitate (Ra,Ba(SO4)(s)). The assumption that radium can form a solubility limiting phase may not be justified or necessary if the concentrations of counter ions in the phase are insufficiently high to cause saturation.

Please provide relevant barium and sulfate concentrations at the site to indicate which phases can be formed.