ML22326A296

Clarification on STPNOC Response to Request for Additional Information Regarding Request for Approval of Alternate Disposal Procedures for Very Low-Level Radioactive Material

ML22326A296
Person / Time
Site:	South Texas
Issue date:	11/22/2022
From:	Harshaw K South Texas
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
NOC-AE-22003931, EPID L 2021-LLL-0022
Download: ML22326A296 (1)

Text

November 22, 2022 NOC-AE-22003931 10 CFR 20.2002 STI: 35400482 Attention: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 South Texas Project Units 1 and 2 Docket Nos. STN 50-498 and STN 50-499 Clarification on STPNOC Response to Request for Additional Information Regarding Request for Approval of Alternate Disposal Procedures for Very Low-Level Radioactive Material (EPID: L 2021-LLL-0022)

Reference:

Letter from K. Harshaw, STPNOC; to NRC; STPNOC Response to Request for Additional Information Regarding Request for Approval of Alternate Disposal Procedures for Very Low-Level Radioactive Material (EPID: L 2021-LLL-0022); August 19, 2022; NOC-AE-22003912; ML22231A469.

STP Nuclear Operating Company (STPNOC) submitted the letter referenced in response to NRC requests for additional information (RAI) regarding STPNOCs request for approval of alternate disposal procedures for very low-level radioactive material. Attachment 1 clarifies and updates information provided in the STPNOC RAI response regarding the total disposal volume being requested and the list of potentially included radionuclides and their limiting concentrations and activity.

There are no commitments in this letter.

If there are any questions regarding this letter, please contact Zachary Dibbern at (361) 972-4336 or me at (361) 972-4778.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on _______________________

Kimberly A. Harshaw Executive VP and CNO Attachments:

1. STPNOC Clarification on Total Disposal Volume and List of Radionuclides

2. Revised RESRAD Summary Report for Onsite of the Generic Landfill

NOC-AE-22003931 Page 2 of 2 cc:

Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 1600 E. Lamar Boulevard Arlington, TX 76011-4511 Dennis Galvin Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Operating Reactor Licensing Licensing Project Branch 4 Gregory Kolcum Senior Resident Inspector, South Texas Project U.S. Nuclear Regulatory Commission Chad Stott Resident Inspector, South Texas Project U.S. Nuclear Regulatory Commission

NOC-AE-22003931 Attachment 1 Attachment 1 STPNOC Clarification on Total Disposal Volume and List of Radionuclides

NOC-AE-22003931 Attachment 1 Page 1 of 2 STPNOC Clarification on Total Disposal Volume and List of Radionuclides Total Disposal Volume STPNOC is requesting approval to dispose of a total volume of 5,000 cubic meters of very low-level radioactive material over the lifetime of this request.

Revised Response to RAI-3.a STPNOC is revising the response to RAI-3.a, previously submitted in the August 19, 2022 letter, to include additional potential radionuclides that may be present in shipments. STPNOC is specifying an administrative concentration limit for each radionuclide as part of this 10 CFR 20.2002 Alternate Disposal Procedure request. Also listed for each radionuclide are the corresponding limiting concentrations and activity per the Texas Administrative Code (TAC).

a. Provide a summary of the input parameters for the sites being considered for disposal under the requested action and resulting doses from the RESRAD [RESidual RADioactive]-ONSITE and RESRAD-OFFSITE analyses (these could be the summary reports) as well as any other technical analyses performed for this submittal. Also provide the basis for considering specific modeling assumptions used in these calculations.

STP Response:

List of Potential Radionuclides, Concentration Limits, and The list of potential Activity Limits radionuclides and their limiting concentrations and activity STP TAC limits are provided in the table Potential Administrative TAC Activity Concentration on the right titled List of Isotopes Concentration Limit pCi Potential Radionuclides, Limit pCi/gm Limit pCi/gm Concentration Limits, and Be7 1.00E+00 2.0E+04 None Activity Limits. This table C14 1.00E+00 8.0E+03 1.00E+08 includes the expected radionuclides that have been Co57 1.00E+00 5.0E+03 1.00E+08 detected in previous Co58 1.00E+00 1.0E+03 1.00E+07 shipments as well as Co60 5.00E-01 1.00E+06 5.0E+02 additional radionuclides that are not necessarily expected Cr51 2.00E+00 2.0E+04 1.00E+09 but could potentially be Cs137 1.50E-01 None 1.00E+07 included in the future. Fe55 1.00E+01 8.0E+03 1.00E+08 H3 2.00E+01 3.0E+04 1.00E+09 Radionuclides not listed or in excess of the STP Mn54 1.00E+00 1.0E+03 1.00E+07 Administrative Concentration Ni63 6.00E+00 None 1.00E+07 Limits in the List of Potential Sb125 4.00E+00 1.0E+03 1.00E+07 Radionuclides, Concentration 1.00E-05 1.00E+05 Sr90 None Limits, and Activity Limits would not be included in any Zn65 1.00E+00 1.0E+03 1.00E+07 shipments allowed by this Zr95 1.00E+00 6.0E+02 1.00E+07 request.

NOC-AE-22003931 Attachment 1 Page 2 of 2 See Attachment 2, Revised RESRAD Summary Report for Onsite of the Generic Landfill, for the input parameters. Note that the input parameters for the Revised RESRAD Summary Report are based on the expected average shipment.

The basis for the specific modeling assumptions were developed from a generic landfill based in Southeast Texas. The parameters for disposal of waste at this generic site were used, and from these parameters conservative assumptions were used to demonstrate compliance. Any landfill used for disposal of the very low-level radioactive waste would be analyzed to meet these bases.

For activities occurring offsite, RESRAD calculations were performed to verify anticipated dose to a member of the public, landfill workers, and drivers were below 5 mrem per year, which is lower than the minimum of 100 mrem/hr required in 10 CFR 20.1301. Specific considerations were incorporated into RESRAD where appropriate for local pathways.

Overall, potential dose and health impacts to the public and to workers from the disposal activities are expected to be small and maintained ALARA.

NOC-AE-22003931 Attachment 2 Attachment 2 Revised RESRAD Summary Report for Onsite of the Generic Landfill