ML25267A236
| ML25267A236 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 09/25/2025 |
| From: | Shilpa Arora Plant Licensing Branch III |
| To: | Rhoades D Constellation Energy Generation, Constellation Nuclear |
| Arora, S | |
| References | |
| EPID L-2024-LLA-0069 | |
| Download: ML25267A236 (5) | |
Text
September 25, 2025 Mr. David P. Rhoades Senior Vice President Constellation Energy Generation, LLC President and Chief Nuclear Officer Constellation Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3 - CORRECTION TO AMENDMENT NOS. 287 AND 280 RE: ADOPTION OF 10 CFR 50.69, RISK-INFORMED CATEGORIZATION AND TREATMENT OF STRUCTURES, SYSTEMS, AND COMPONENTS FOR NUCLEAR POWER REACTORS (EPID L-2024-LLA-0069)
Dear Mr. Rhoades:
On August 7, 2025, the U.S. Nuclear Regulatory Commission (NRC) issued Amendment Nos.
287 and 280 to Renewed Facility Operating License Nos. DPR-19 and DPR-25 for Dresden Nuclear Power Station, Units 2 and 3, respectively. These amendments revised Renewed Facility Operating Licenses to adopt Title 10 of the Code of Federal Regulations (10 CFR) 50.69 in response to your license amendment request (LAR) dated May 28, 2024, as supplemented by letters dated March 21, 2025, and April 23, 2025.
Subsequent to issuance of the above amendments, it was noticed that page 9 of the safety evaluation (SE), included in the amendment package, had listed an incorrect section number for the PRA standard in the SE section titled, External Events: Seismic PRA. Enclosed with this letter is the corrected SE page 9 with which we ask you to replace the previously issued SE page 9. The NRC concludes that this correction is entirely editorial in nature and does not change the staffs conclusions in the SE for the amendments, nor does the change affect the no significant hazard consideration, as published in the Federal Register on August 6, 2024 (89 FR 63991).
D. Rhoades If you have any questions regarding this matter, please contact me at (301) 415-1421 or by e-mail at Surinder.Arora@nrc.gov.
Sincerely,
/RA/
Surinder S. Arora, Project Manager Plant Licensing Branch III Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-237 and 50-249
Enclosure:
Corrected SE Page 9 for Amendment Nos. 287/280 cc: Listserv
Enclosure Correct SE Page 9 External Events: Seismic PRA In accordance with section 5-1.2 of the PRA standard, it is assumed that full-scope, internal events, at-power, Level 1 and Level 2 LERF PRAs exist and that those PRAs are used as the basis for the SPRA. Therefore, the technical acceptability of the IEPRA model used as the foundation for the SPRA is an important consideration.
Section 3.3 of the enclosure to the LAR states that a focused-scope peer review was performed in June 2023 on the IEPRA model, which was after the SPRA had a F&O closure review in June 2022. In the LAR supplement response dated March 21, 2025, to APLC question 1.b, the licensee included an evaluation of IEPRA changes after June 2022 on the SPRA F&O closure review and results. Based on its review of the IEPRA model and evaluation of IEPRA change impacts on the SPRA, the NRC staff finds that the IEPRA is technically acceptable to be used as the foundation for the SPRA.
In Section 3.2.3 of the enclosure to the LAR dated May 28, 2024, the licensee stated that the proposed categorization process will use a peer-reviewed, plant-specific SPRA model. The NRC staffs review of the technical acceptability of the SPRA model for this application is discussed below.
Seismic PRA Peer-Review History The NRC staffs review of the licensees SPRA was based on the results of the peer review and the associated F&O closure review for closure of F&Os described in LAR Section 3.3 and attachment 3. The last full-scope peer review of the SPRA was performed in January 2019 against the SPRA requirements in ASME/ANS RA-Sb-2013 (Reference [19]), also known as Addendum B of the 2008 ASME/ANS PRA standard. RG 1.200, Revision 2, endorses ASME/ANS PRA Standard RA-Sa-2009, also known as Addendum A of the 2008 ASME/ANS PRA standard, but does not endorse Addendum B.
In the LAR supplement, response to APLC question 2, the licensee demonstrated that the supporting requirements (SRs) in part 5 of Addendum B are consistent with those in Addendum A. Based on its review of the licensees comparison of SRs of part 5 of Addendum B of the PRA standard compared to those in Addendum A, the NRC staff finds the licensees use of Addendum B to be an acceptable alternative to the NRC-endorsed approach for this application because it adequately addresses the technical elements for the development of a SPRA.
The SPRA peer review and F&O closure review used NEI 12-13 (Reference [20]) but did not explicitly address the NRC letter dated March 7, 2018, regarding external hazard peer reviews (Reference [21]). In the LAR supplement, response to APLC question 1.a, the licensee stated that the Dresden SPRA 2019 peer review and 2022 F&O closure processes are compliant with the NRC clarifications on NEI 12-13. Based on the information provided by the licensee as well as the documented comparison of the NEI 12-13 comments with the SPRA peer review and F&O closure processes, the NRC staff finds the performance of the SPRA peer review and F&O closure process to be acceptable.
The NRC staff reviewed the SPRA peer review results and the licensee's resolution of the results and finds that the Dresden SPRA was appropriately peer-reviewed consistent with RG 1.200, Revision 2, and the F&Os have been closed using an NRC-approved approach.
ML25267A236 OFFICE DORL/LPL3/PM DORL/LPL3/LA DORL/LPL3/BC DORL/LPL3/PM NAME SArora SLent IBerrios SArora DATE 09/23/2025 09/25/2025 09/25/2025 09/25/2025