ML25335A095
| ML25335A095 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 12/01/2025 |
| From: | Greg Warnick NRC Region 4 |
| To: | Gerfen P Pacific Gas & Electric Co |
| References | |
| IR 2025401 | |
| Download: ML25335A095 (0) | |
Text
OFFICIAL USE ONLY - SECURITY-RELATED INFORMATION Enclosure(s) transmitted herewith contain(s) SUNSI. When separated from enclosure(s), this transmittal document is decontrolled.
OFFICIAL USE ONLY - SECURITY-RELATED INFORMATION December 01, 2025 Paula A. Gerfen, Senior Vice President and Chief Nuclear Officer Pacific Gas and Electric Company P.O. Box 56 Mail Code 104/6 Avila Beach, CA 93424
SUBJECT:
DIABLO CANYON NUCLEAR POWER PLANT - CYBERSECURITY INSPECTION REPORT 05000275/2025401 AND 05000323/2025401
Dear Paula A. Gerfen:
On August 14, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Diablo Canyon Nuclear Power Plant. On September 18, 2025, the NRC inspectors discussed the results of this inspection with you and other members of your staff. The results of this inspection are documented in the enclosed report.
Due to the temporary cessation of government operations, which commenced on October 1, 2025, the NRC began operating under its Office of Management and Budget-approved plan for operations during a lapse in appropriations. Consistent with that plan, the NRC operated at reduced staffing levels throughout the duration of the shutdown. However, the NRC continued to perform critical health and safety functions and make progress on other high-priority activities associated with the ADVANCE Act and Executive Order 14300. On November 13, 2025, following the passage of a continuing resolution, the NRC resumed normal operations. However, due to the 43-day lapse in normal operations, the Office of Nuclear Reactor Regulation granted the Regional Offices an extension on the issuance of inspection reports that could not be issued within 45 days after the end of the inspection because of the shutdown.
Two findings of very low security significance (Green) are documented in this report. These findings involved violations of NRC requirements. We are treating these violations as non-cited violations (NCVs) consistent with Section 2.3.2 of the Enforcement Policy.
OFFICIAL USE ONLY - SECURITY-RELATED INFORMATION P. Gerfen 2
OFFICIAL USE ONLY - SECURITY-RELATED INFORMATION If you contest the violations or the significance or severity of the violations documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:
Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region IV; the Director, Office of Enforcement; the Director, Office of Nuclear Security and Incident Response; and the NRC Resident Inspector at Diablo Canyon Nuclear Power Plant.
The following cross-cutting aspect was assigned to a finding using Inspection Manual Chapter 0310 Aspects Within Cross-Cutting Areas: [H.3] - Change Management.
If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region IV; the Director, Office of Nuclear Security and Incident Response; and the NRC Resident Inspector at Diablo Canyon Nuclear Power Plant.
This letter will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.
The enclosed report contains Security-Related Information, so the enclosed report will not be made publicly available in accordance with Title 10 of the Code of Federal Regulations (10 CFR) 2.390(d)(1). If you choose to provide a response that contains Security-Related Information, please mark your entire response Security-Related Information-Withhold from public disclosure under 10 CFR 2.390 in accordance with 10 CFR 2.390(d)(1) and follow the instructions for withholding in 10 CFR 2.390(b)(1). The NRC is waiving the affidavit requirements for your response in accordance with 10 CFR 2.390(b)(1)(ii).
Sincerely, Gregory G. Warnick, Chief Engineering Branch 2 Division of Operating Reactor Safety Docket Nos. 05000275 and 05000323 License Nos. DPR-80 and DPR-82
Enclosure:
As stated cc w/o encl: Distribution via LISTSERV Signed by Warnick, Gregory on 12/01/25
ML25318A128 (Cover letter w/ enclosure(s))
ADAMS ACCESSION NUMBER: ML25335A095 (Cover letter)
Entire Report:
SUNSI Review Non-Sensitive Sensitive Publicly Available Non-Publicly Available Cover Letter Only:
SUNSI Review By: STG Non-Sensitive Sensitive Publicly Available Non-Publicly Available OFFICE SRI:DORS/EB2 SRI:DORS/EB2 C:DORS/EB2 NAME SGraves GPick GWarnick SIGNATURE
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DATE 11/14/25 11/17/25 12/01/25