ML25269A071
| ML25269A071 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 09/29/2025 |
| From: | Samson Lee Plant Licensing Branch IV |
| To: | Gerfen P Pacific Gas & Electric Co |
| Lee S, 301-415-3158 | |
| References | |
| EPID L-2025-LLA-0139 | |
| Download: ML25269A071 (3) | |
Text
September 29, 2025 Ms. Paula Gerfen Senior Vice President, Generation and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant P.O. Box 56 Avila Beach, CA 93424
SUBJECT:
DIABLO CANYON NUCLEAR POWER PLANT, UNITS 1 AND 2 -
ACCEPTANCE OF REQUESTED LICENSING ACTION RE: ADOPTION OF EMERGENCY ACTION LEVEL SCHEME PURSUANT TO NEI 99-01, REVISION 7, DEVELOPMENT OF EMERGENCY ACTION LEVELS FOR NON-PASSIVE REACTORS (EPID L-2025-LLA-0139)
Dear Ms. Gerfen:
By letter dated August 27, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25239B075), Pacific Gas and Electric Company (the licensee) submitted a license amendment request (LAR) for Diablo Canyon Nuclear Power Plant, Units 1 and 2 (Diablo Canyon). The proposed amendment would revise the Emergency Action Levels (EALs) to reflect changes contained in Nuclear Energy Institute (NEI) 99-01, Revision 7, Development of Emergency Action Levels for Non-Passive Reactors, dated September 2024 (ML24274A312). The purpose of this letter is to provide the results of the U.S.
Nuclear Regulatory Commission (NRC) staffs acceptance review of this LAR.
Consistent with Section 50.90 of Title 10 of the Code of Federal Regulations (10 CFR), an application for an amendment to a license (including the technical specifications) must fully describe the changes requested, and following as far as applicable, the form prescribed for original applications. Section 50.34 of 10 CFR addresses the content of technical information required. This section stipulates that the submittal address the design and operating characteristics, unusual or novel design features, and principal safety considerations.
The NRC staff considered the guidance in Office of Nuclear Reactor Regulation, Office Instruction LIC-109, Revision 3, Acceptance Review Procedures for Licensing Basis Changes, (ML20036C829) in conducting this review. The NRC staff has completed the acceptance review of the LAR and concluded that it does provide technical information in sufficient detail to enable the NRC staff to start its detailed technical review and make an independent assessment regarding the acceptability of the proposed amendment in terms of regulatory requirements and the protection of public health and safety and the environment.
The NRC staff notes that this is the first of a number of applications to be submitted based on NEI 99-01, Revision 7. The NRC staff identified specific information needed to facilitate the NRC staffs detailed review during the June 4, 2025, NRC public meeting on NEI 99-01, Revision 7, submission process (ML25147A142). To improve the effectiveness and efficiency of the NRC
staffs review and to support the requested review schedule, the NRC staff plans to conduct a regulatory audit to evaluate detailed information not provided in the LAR. The following are specific examples of detailed information that the NRC staff identified during the acceptance review required to complete the NRC staffs detailed technical review:
- 1. Technical justification or objective evidence for the site-specific changes to Appendix D -
Emergency Action Level Technical Basis Manual:
- a. the front-sections (e.g., section 3.0, Guidance On Making Emergency Classifications);
- b. section 5.0, Definitions, Acronyms & Abbreviations; and,
- c. section 7.1 - Attachment 1, Emergency Action Level Technical Basis.
- 2. An example of Diablo Canyon EAL Wallboards for the proposed changes.
- 3. A statement as to whether the licensee intends to carry over the instrumentation values and associated calculations from the last approved EAL scheme.
This is not an exhaustive list and additional information needed to complete the NRC staffs detailed review will be requested through the audit or request for additional information process.
The NRC staff has evaluated precedence related to this request and determined that, on average, the reviews have required 335 hours0.00388 days <br />0.0931 hours <br />5.539021e-4 weeks <br />1.274675e-4 months <br /> and 10.9 months. Because the licensees submittal is the first application of NEI 99-01, Revision 7, and was submitted before the NRC staff endorsement of NEI 99-01, Revision 7, in a regulatory guide, the NRC staff is estimating a 15 percent increase in resources to complete the review. Based on that, the NRC staffs resource estimate for this review is 385 hours0.00446 days <br />0.107 hours <br />6.365741e-4 weeks <br />1.464925e-4 months <br />. However, the NRC staff will strive to meet the licensees requested date of March 31, 2026. If emergent complexities or challenges arise during the NRC staffs review that affect the initial forecasted completion date or result in significant changes to the estimated review hours, the reasons for those changesalong with updated estimateswill be communicated during routine interactions with the assigned project manager. These estimates are based on the NRC staffs initial review of the application and may change due to several factors, including requests for additional information, unanticipated expansion of the review scope, or hearing-related activities.
If you have any questions, please contact me at 301-415-3168 or via email at Samson.Lee@nrc.gov.
Sincerely,
/RA/
Samson S. Lee, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-275 and 50-323 cc: Listserv
ML25269A071 OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/LA NSIR/DPR/RLB/BC NAME SLee PBlechman JQuichocho (ERobinson for)
DATE 9/22/2025 9/29/2025 9/23/2025 OFFICE NRR/DORL/LPL4/BC NRR/DORL/LPL4/PM NAME TNakanishi SLee DATE 9/29/2025 9/29/2025