ML25154A361
| ML25154A361 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 06/18/2025 |
| From: | Jack Parrott Reactor Decommissioning Branch |
| To: | Pearson B Omaha Public Power District |
| Shared Package | |
| ML25154A358 | List: |
| References | |
| EPID L-2024-LLA-0095 | |
| Download: ML25154A361 (1) | |
Text
Benjamin Pearson, Regulatory Assurance and Emergency Planning Manager Omaha Public Power District Fort Calhoun Station 9610 Power Lane Blair, NE 68008
SUBJECT:
FORT CALHOUN STATION, UNIT 1 - AUDIT REPORT FOR OMAHA PUBLIC POWER DISTRICT REQUEST TO REVISE LICENSE TERMINATION PLAN REQUIREMENTS AND REQUEST FOR ADDITIONAL INFORMATION (EPID NO. L-2024-LLA-0095)
Dear Benjamin Pearson:
Revision 0 of the Fort Calhoun Station (FCS) License Termination Plan (LTP) was submitted by Omaha Public Power District (OPPD) to the U.S. Nuclear Regulatory Commission (NRC) in accordance with 10 Code of Federal Regulations (CFR) 50.82(a)(9) on August 3, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No.
(ML21271A178). After review of Revision 0 by NRC, but before approval, Revision 1 (LTP, Rev.
- 1) of the FCS LTP was submitted on December 6, 2023 (ML23346A152). Under the provisions of 10 CFR 50.82(a)(10), LTP, Rev.1 was approved by the NRC on January 31, 2024 (ML24019A145) by amendment of NRC license No. DPR-40. Revision 2 of the LTP (LTP, Rev.
- 2) was submitted to NRC on June 18, 2024 (ML24177A132). Supplemental information for LTP, Rev. 2 review was submitted on October 2, 2024 (ML24276A217), January 16, 2025 (ML25016A212), and March 24, 2025 (ML25083A220).
A regulatory audit of LTP, Rev. 2 was implemented on January 16, 2025, to identify information to support the basis of the licensing decision and to allow the NRC staff to more efficiently gain insights necessary to complete its review of the LTP Revision license amendment request (LAR). The regulatory audit ended on March 31, 2025. Enclosed is a report on the regulatory audit. The audit report does not make any regulatory conclusions or findings but is part of the administrative record of the NRC staffs review of the application and may provide information supporting the NRC staffs safety evaluation of the FCS LAR. The audit followed the plan provided by e-mail dated January 14, 2025 (ML25023A155), unless otherwise noted in the enclosed report. The regulatory audit resolved many of the issued identified in NRCs review of the LTP Rev 2 application. Issues that should be followed up by the licensee are identified in the NRC audit report.
See Enclosure 2 for the NRCs requests for additional information (RAI) needed to complete the review. Please provide a response to the RAI or a written request for additional time to respond, including the proposed response date and a brief description of the reason, by 30 days from the date of this letter.
June 18, 2025
B. Pearson In accordance with 10 CFR 2.390 of the NRCs Agency Rules of Practice and Procedure, a copy of this letter will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records component of NRCs ADAMS. ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html.
If you have any questions, please contact me at (301)-415-6634 or by electronic mail at jack.parrott@nrc.gov.
Sincerely, Jack D. Parrott, Senior Project Manager Reactor Decommissioning Branch Division of Decommissioning, Uranium Recovery and Waste Projects Office of Nuclear Material Safety and Safeguards Docket No. 50-285 License No. DPR-40
Enclosure:
1: Audit Summary and Audit Summary of Topics Attachment 2: Request for Additional Information cc w/
Enclosure:
Fort Calhoun Listserv Signed by Parrott, Jack on 06/18/25
ML25154A358; Ltr ML25154A361 OFFICE NMSS/DUWP/RDB NMSS/DUWP/RDB NMSS/DUWP/RDB NAME JParrott SAnderson JParrott DATE 6/5/2025 6/17/2025 6/18/2025 OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS REGULATORY AUDIT
SUMMARY
REGARDING LICENSE AMENDMENT REQUEST TO REVISE THE LICENSE TERMINATION PLAN OMAHA PUBLIC POWER DISTRICT FORT CALHOUN STATION, UNIT 1 DOCKET NO. 50-285, LICENSE NO. DPR-40
1.0 BACKGROUND
By letter dated June 18, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24177A132), and as supplemented by letter dated October 2, 2024 (ML24276A217). Omaha Public Power District (OPPD or the licensee) requested the U.S.
Nuclear Regulatory Commission (NRC) to approve a request to amend the license for Fort Calhoun Station, Unit No. 1 (FCS). The amendment would approve Revision 2 of the FCS License Termination Plan (LTP), which was originally approved as Revision 1 by license amendment dated January 31, 2024 (ML24019A145). The revision changes the dose calculation for the auxiliary building basement, the requirements for remediation, and survey methodologies in the LTP.
This report summarizes the regulatory audit conducted by the NRC staff in connection with its review of the FCS LTP Revision 2 application. The audit report does not make any regulatory conclusions or findings but is part of the administrative record of the NRC staffs review of the application and may provide information supporting the NRC staffs safety evaluation of FCS LTP Revision 2. The audit followed the plan provided by e-mail dated January 14, 2025 (ML25023A155), unless otherwise noted in this audit report.
2.0 AUDIT DATES The regulatory audit was conducted from January 16, 2025, to March 31, 2025, via posting of information on an online portal established by the licensee, which allowed the NRC staff to view documents remotely via the internet, and through virtual meetings with the FCS staff on January 16, 2025, February 6, 2025, February 26, 2025, and March 13, 2025.
3.0 AUDIT ACTIVITIES On January 16, 2025, a virtual entrance meeting for the audit was held between the NRC staff and representatives of FCS to discuss the audit process and provide an overview of the specific focus topics provided to the licensee in the audit plan. The purpose of the entrance meeting was to provide an overview of the audit process, the scope of the audit, and a list of the information needed by NRC staff to begin the audit.
The NRC staff reviewed the LTP Revision 2 LAR and provided the audit requests, which are described in the attachment to this audit report. On January 28, 2025, the licensee established the online portal requested in the NRCs audit plan.
The NRC staff discussed the specific focus topics and the information the licensee provided in the online portal with representatives of FCS through virtual meetings held between the NRC staff and FCS representatives on January 16, 2025, February 6, 2025, February 26, 2025, and March 13, 2025.
Technical discussions during the audit were focused on the following areas: Derived Concentration Guideline Levels (DCGLs), Use of DCGLs from Year with Highest Relative Dose vs. Peak Year, New Areas to be Grouted, Use of Extracted Basement and Trench Material as Fill, Area Factors, Release Rate from Grout and Cement, Description of the Release from Pipes and Continuing Characterization, Scan minimum detectable concentration (MDC)
Inputs, Scan MDC, Insignificant Contributors Verification, and Investigations & Remediation.
During the audit, various topics were discussed within each of the major areas. The NRC staff and the licensee discussed and determined closure paths for each audit request as described in the attachment to this report.
For DCGLs - The audit requests centered around inconsistencies between tables in Rev 2 of the LTP and in the technical analysis references supporting the revised DCGLs that the licensee was proposing to use. NRC was also seeking clarification of the different DCGL values described in the reference analysis and in the LTP revision. Clarification was also sought on the process used for calculating the compliance DCGLs for different residually contaminated media.
Lastly, the audit requests on DCGLs requested clarification on which dose scenario was applicable to the DCGL values proposed.
For Use of DCGLs from Year with Highest Relative Dose vs. Peak Year - NRC provided requests to clarify the basis for using an alternate approach of determining the compliance DCGLs based on the year with the highest relative dose instead of using the largest DCGL for a specific radionuclide, regardless of the year in which the dose occurs, rather than the approved approach from the previously approved LTP.
For New Areas to be Grouted - Clarification was sought on what other areas of the Auxiliary Building basement, besides the auxiliary building east trenches, were planned to be grouted and to use DCGLs developed for the East Trenches. Then, if other areas in the Auxiliary Building basement were planned to be grouted, clarification was sought on if these new areas would use mixture fractions from the LTP or newly developed mixture fractions on a case-by-case basis using characterization, RA, or RASS data.
For Use of Extracted Basement and Trench Material as Fill - Clarify how the grouted trenches DCGLs fit into the walls and floors DCGLs in regard to the total compliance calculation for the site.
For Area Factors - Clarification was needed on if a trench is a survey unit and how the specific radionuclides, specific exposure scenarios, specific exposure pathways, and specific modeling parameters were considered when evaluating a specific survey unit regarding the regulatory dose requirements termination of the license.
For Release Rate from Grout and Cement - Staff was seeking licensee support for release rates from the grout and cement to make a determination that dose criteria specified in 10 CFR 20.1402 is not underestimated.
For Description of the Release from Pipes and Continuing Characterization - NRC staff was seeking a description of the spread of contamination in the trenches to determine if the continuing characterization and/or final status survey plans would be adequate to meet the dose requirements for license termination.
For Scan MDC Inputs - Clarification was needed on what typical detector height and scan rate inputs would be utilized during surveys, as well as the scan MDC values related to these inputs so that NRC could verify that the methods to be used will be consistent with the stated MDCs.
For Scan MDC - NRC staff was seeking confirmation of which detector will be used on auxiliary building basement upper walls and how the scan MDC will meet LTP requirements or an explanation on what processes will be used to ensure sufficient scan sensitivity to detect small areas of elevated activity.
For Insignificant Contributors Verification - NRC staff was seeking clarification on if RASS samples were used to verify IC dose in the auxiliary building east trench or not.
For Investigations & Remediation - NRC staff sought clarification on whether the investigation levels and remediation will be based on base case DCGLs or the DCGLemc as stated in the revised LTP.
4.0 RESULTS OF THE AUDIT The NRC staff gained insight into the licensees approach to address the technical areas identified in each of the major areas described in Section 3.0 of this report. Based on discussions during the audit, the licensee intends to make changes to the FCS LTP Rev 2 and submit a revised LTP on the docket in order to address items identified during the audit and to expand the scope of the LTP to include other grouted areas of the site beyond the auxiliary building basement.
The table provided in the attachment to this audit report provides a comprehensive summary of the topics discussed during the audit in each of the major areas and the resolution or proposed path to resolution, as applicable.
5.0 AUDIT PARTICIPANTS List of audit participants from the NRC, OPPD, and OPPD consultants:
NRC Staff OPPD Staff OPPD Consultants Randy Fedors Nate Fuguet Jack Parrott Adam Schwartzman Ben Pearson From EnergySolutions Barb Dotson Dale Randall Jason Spaide Robert Yetter II Robert Yetter III From Radiation Safety & Control Services, Inc.
John Clements Joe Davis Dave Fauver Terry Sullivan 6.0 DOCUMENTS REVIEWED The table below provides a list of documents that the NRC staff reviewed during the audit.
Document/File Title Revision/Date Agencywide Documents Access and Management System (ADAMS) Accession No. ML24177A132 Fort Calhoun Station, Unit 1, License Amendment Request (LAR) To Revise License Termination Plan (LTP)
LTP, Rev. 2, submitted to NRC on June 18, 2024.
ADAMS Accession No. ML24276A217 Fort Calhoun Station, Unit 1, Independent Spent Fuel Storage Installation -
Response to Application For License Amendment Request to Revise the License Termination Plan -
Supplemental Information Needed, EPID L-2024-LLA-0095 Supplemental information for LTP, Rev. 2 (ML24276A217),
submitted to NRC on October 2, 2024.
Caclulations (sic) in Support of FCS LTP Chapter 6 Revision 2.xlsx Caclulations (sic) in Support of FCS LTP Chapter 6 Revision 2 Updated Jan 9, 2025 FC-24-004 Rev 1 DCGLs and Survey Action Levels for the Auxiliary Building East Trenches Final 03152024.pdf DCGLs, Remediation Strategy and Survey Methodology for the Auxiliary Building East Trenches, FC-24-004, Revision 1 March 15, 2024
Attachment:
as stated