DCL-25-015, Diablo Cranyon, Units 1 and 2 - Response to Request for Additional Information for License Amendment Request 24-03, Revision to Technical Specification 5.5.16 for Permanent Extension of Type a and Type C Leak Rate Test Frequencies
| ML25043A418 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 02/12/2025 |
| From: | Rogers J Pacific Gas & Electric Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| DCL-25-015 | |
| Download: ML25043A418 (1) | |
Text
Justin E. Rogers Station Director Diablo Canyon Power Plant Mail code 104/5/502 P.O. Box 56 Avila Beach, CA 93424 805.545.3088 Justin.Rogers@pge.com A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Diablo Canyon
- Palo Verde
- Wolf Creek 10 CFR 50.90 PG&E Letter DCL-25-015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Diablo Canyon Units 1 and 2 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Response to Request for Additional Information for License Amendment Request 24-03, Revision to Technical Specification 5.5.16 for Permanent Extension of Type A and Type C Leak Rate Test Frequencies
References:
- 1. PG&E Letter DCL-24-070, License Amendment Request 24-03, Revision to Technical Specification 5.5.16 for Permanent Extension of Type A and Type C Leak Rate Test Frequencies, dated 7/31/2024 (ADAMS Accession No. ML24213A331)
- 2. NRC Letter Request for additional information: Diablo Canyon request to revise Technical Specification 5.5.16 for permanent extension of Type A and Type C leak rate test frequencies, dated January 14, 2025 (ADAMS Accession No. ML25014A344)
Dear Commissioners and Staff:
Pursuant to 10 CFR 50.90, Pacific Gas and Electric Company (PG&E) submitted Reference 1 that requested approval of a proposed amendment to revise Technical Specification (TS) 5.5.16, Containment Leakage Rate Testing Program.
In Reference 2, the NRC provided a request for additional information. The Enclosure provides a response to the requested additional information.
The response in the Enclosure does not change the intent of the significant hazards evaluation or environment evaluation contained in Reference 1.
PG&E makes no new or revised regulatory commitments (as defined by NEI 99-04) in this letter.
m PacHic Gas and Electric Company*
Document Control Desk PG&E Letter DCL-25-015 Page 2 A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Diablo Canyon
- Palo Verde
- Wolf Creek Pursuant to 10 CFR 50.91, PG&E is sending a copy of this letter to the California Department of Public Health.
If you have any questions or require additional information, please contact James Morris, Manager, Regulatory Services, at 805-545-4609.
I state under penalty of perjury that the foregoing is true and correct.
Sincerely, Justin E. Rogers Station Director Date misf/51230373-2 Enclosure cc:
Diablo Distribution cc/enc: Anthony Chu, Branch Chief, California Department of Public Health Mahdi O. Hayes, NRC Senior Resident Inspector Samson S. Lee, NRR Project Manager John D. Monninger, NRC Region IV Administrator 2/12/2025
Enclosure PG&E Letter DCL-25-015 1
RAI Currently, Diablo Canyon TS 5.5.16 paragraph a, in part states:
A program shall be established to implement the leakage rate testing of the containment as required by 10 CFR 50.54(o) and 10 CFR 50, Appendix J, Option B, as modified by approved exemptions. This program shall be in accordance with the guidelines contained in RG 1.163, Performance-Based Containment Leak-Test Program, dated September 1995 The licensee proposed change to Diablo Canyon TS 5.5.16 paragraph a, would state (with recommended changes using strike-out for deleted text and bold-type for added text for clarification purposes):
A program shall be established to implement the leakage rate testing of the containment as required by 10 CFR 50.54(o) and 10 CFR 50, Appendix J, Option B, as modified by approved exemptions. This program shall be in accordance with the guidelines contained in RG 1.163, Revision 1, Performance-Based Containment Leak-Test Program, dated September 1995 June 2023, and NEI 94-01, Revision 3-A, Industry Guideline for Implementing Performance-Based Option of 10 CFR 50, Appendix J, dated July 2012 As noted above, RG 1.163, Revision 1, was issued in June of 2023. This revision of the RG endorsed the guidance in NEI 94-01, Revision 3-A, issued July 2012, for implementing Option B of Appendix J to 10 CFR Part 50, subject to the regulatory positions listed in Section C of the RG. In the proposed change, the licensee includes the NEI document in the TS markup in addition to citing RG 1.163, Revision 1. The LAR does not appear to provide an explanation as to why the NEI guidance was explicitly included in the TS markup, given that the RG 1.163 endorses the NEI guidance. As such, the rationale for why the licensee cited the NEI document in Diablo Canyon TS 5.5.16 is not clear to the NRC staff. Providing information that clarifies why the NEI guidance is cited would help to ensure compliance with program requirements that are necessary to assure operation of the facility in a safe manner. Therefore, the NRC staff requests that the licensee provide information that explains the rationale for citing both the RG and NEI guidance in Diablo Canyon TS 5.5.16.
In addition, the LAR cover letter and LAR Section 4.3, Significant Hazards Consideration, proposed change description appears to suggest that 10 CFR 50, Appendix J, Option B is being replaced with a reference to NEI 9401, Revision 3-A. These descriptions appear to be an editorial error. The description for the proposed change provided in LAR Section 1, Summary Description, appears to be consistent with the proposed TS markups, which retain reference to Appendix J. Therefore, the NRC staff requests that the licensee explain the apparent inconsistency in the proposed change descriptions contained in the LAR and make any changes, as appropriate.
PG&E Response As stated in the RAI, a reference to NEI 94-01, Revision 3-A, in the TS markup in addition to citing RG 1.163, Revision 1, is not necessary given that the RG endorses the NEI guidance.
Enclosure PG&E Letter DCL-25-015 2
PG&E therefore revises the proposed DCPP Units 1 and 2 TS 5.5.16, Containment Leakage Rate Testing Program, changes by removing the reference to NEI 94-01, Revision 3-A.
A revised Proposed Technical Specification Page Markup and Proposed Retyped Technical Specification are provided with this letter, which replace the attachments provided in PG&E Letter DCL-24-070, License Amendment Request 24-03, Revision to Technical Specification 5.5.16 for Permanent Extension of Type A and Type C Leak Rate Test Frequencies, dated 7/31/2024 (ADAMS Accession No. ML24213A331).
In addition, the paragraphs in the LAR cover letter and LAR Section 4.3, Significant Hazards Consideration, referenced in the RAI were not intended to suggest that 10 CFR 50, Appendix J, Option B is being replaced with a reference to NEI 94 01, Revision 3-A. For clarity, the 2nd paragraph of Section 4.3 of the LAR is revised as follows:
Specifically, the proposed change revises DCPP Units 1 and 2 TS 5.5.16, Containment Leakage Rate Testing Program, paragraph a., by replacing the reference to Regulatory Guide (RG) 1.163, Performance-Based Containment Leak-Test Program, with a reference to RG 1.163 Revision 1 and 10 CFR 50, Appendix J, Option B -
Performance-Based Requirements, with a reference to NEI 94-01, Revision 3-A.
Enclosure PG&E Letter DCL-25-015 3
Proposed Technical Specification Page Markup
Programs and Manuals 5.5 DIABLO CANYON - UNITS 1 & 2 5.5 Programs and Manuals 5.5.15 Safety Function Determination Program (SFDP) (continued) b.
A required system redundant to the system(s) in turn supported by the inoperable supported system is also inoperable; or c.
A required system redundant to the support system(s) for the supported systems (a) and (b) above is also inoperable.
The SFDP identifies where a loss of safety function exists. If a loss of safety function is determined to exist by this program, the appropriate Conditions and Required Actions of the LCO in which the loss of safety function exists are required to be entered.
5.5.16 Containment Leakage Rate Testing Program a.
A program shall be established to implement the leakage rate testing of the containment as required by 10 CFR 50.54(o) and 10 CFR 50, Appendix J, Option B, as modified by approved exemptions. This program shall be in accordance with the guidelines contained in Regulatory Guide 1.163, "Performance-Based Containment Leak-Test Program," dated September 1995, as modified by the following exceptions:
1.
The visual examination of containment concrete surfaces intended to fulfill the requirements of 10 CFR 50, Appendix J, Option B testing, will be performed in accordance with the requirements of and frequency specified by ASME Section XI Code, Subsection IWL, except where relief has been authorized by the NRC.
2.
The visual examination of the steel liner plate inside containment intended to fulfill the requirements of 10 CFR 50, Appendix J, Option B, will be performed in accordance with the requirements of and frequency specified by ASME Section XI code, Subsection IWE, except where relief has been authorized by the NRC.
3.
The ten-year interval between performance of the integrated leakage rate (Type A) test, beginning May 4, 1994, for Unit 1 and April 30, 1993, for Unit 2, has been extended to 15 years.
b.
The peak calculated containment internal pressure for the design basis loss of coolant accident, Pa, is 43.5 psig. The containment design pressure is 47 psig.
c.
The maximum allowable containment leakage rate, La, at Pa, shall be 0.10% of containment air weight per day.
5.0-16 Unit 1 - Amendment No. 135, 150, 172, 197, 198, 203, Unit 2 - Amendment No. 135, 150, 174, 198, 199, 204, (continued)
Revision 1, June 2023
Enclosure PG&E Letter DCL-25-015 4
Proposed Retyped Technical Specification Page Remove Page Insert Page 5.0-16 5.0-16
Programs and Manuals 5.5 DIABLO CANYON - UNITS 1 & 2 5.5 Programs and Manuals 5.5.15 Safety Function Determination Program (SFDP) (continued) b.
A required system redundant to the system(s) in turn supported by the inoperable supported system is also inoperable; or c.
A required system redundant to the support system(s) for the supported systems (a) and (b) above is also inoperable.
The SFDP identifies where a loss of safety function exists. If a loss of safety function is determined to exist by this program, the appropriate Conditions and Required Actions of the LCO in which the loss of safety function exists are required to be entered.
5.5.16 Containment Leakage Rate Testing Program a.
A program shall be established to implement the leakage rate testing of the containment as required by 10 CFR 50.54(o) and 10 CFR 50, Appendix J, Option B, as modified by approved exemptions. This program shall be in accordance with the guidelines contained in Regulatory Guide 1.163, Revision 1, "Performance-Based Containment Leak-Test Program," dated June 2023, as modified by the following exceptions:
1.
The visual examination of containment concrete surfaces intended to fulfill the requirements of 10 CFR 50, Appendix J, Option B testing, will be performed in accordance with the requirements of and frequency specified by ASME Section XI Code, Subsection IWL, except where relief has been authorized by the NRC.
2.
The visual examination of the steel liner plate inside containment intended to fulfill the requirements of 10 CFR 50, Appendix J, Option B, will be performed in accordance with the requirements of and frequency specified by ASME Section XI code, Subsection IWE, except where relief has been authorized by the NRC.
b.
The peak calculated containment internal pressure for the design basis loss of coolant accident, Pa, is 43.5 psig. The containment design pressure is 47 psig.
c.
The maximum allowable containment leakage rate, La, at Pa, shall be 0.10% of containment air weight per day.
5.0-16 Unit 1 - Amendment No. 135, 150, 172, 197, 198, 203, Unit 2 - Amendment No. 135, 150, 174, 198, 199, 204, (continued)