ML21173A360

Response to Request for Additional Information for Permanent Extension of Type a and Type C Leak Rate Test Frequencies

ML21173A360
Person / Time
Site:	Palo Verde
Issue date:	06/22/2021
From:	Rash B Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-08290-BJR/TNW
Download: ML21173A360 (6)

Text

10 CFR 50.90 BRUCE J. RASH Vice President Nuclear Engineering/Regulatory Palo Verde 102-08290-BJR/TNW Nuclear Generating Station June 22, 2021 P.O. Box 52034 Phoenix, AZ 85072 ATTN: Document Control Desk Mail Station 7602 U.S. Nuclear Regulatory Commission Tel 623.393.5102 Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station Units 1, 2, and 3 Docket Nos. STN 50-528, 50-529, and 50-530 Renewed Operating License Nos. NPF-41, NPF-51, and NPF-74 Response to Request for Additional Information for Permanent Extension of Type A and Type C Leak Rate Test Frequencies By letter number 102-08194, dated January 22, 2021 (Agencywide Documents Access and Management System Accession Number ML21022A408), Arizona Public Service Company (APS) submitted a license amendment request (LAR) to extend the Type A and Type C leak rate test frequencies for Palo Verde Nuclear Generating Station (PVNGS) Units 1, 2, and 3.

The Nuclear Regulatory Commission (NRC) staff requested additional information to complete their review with regard to the proposed changes for the permanent extension of Type A and Type C leak rate test frequencies for PVNGS Units 1, 2, and 3. A clarifying phone call was held between the NRC staff and APS on May 26, 2021, to discuss the additional information needed. The APS response to the request for additional information is provided in the enclosure to this letter.

No new commitments are being made to the NRC by this letter.

If you have any questions or require additional information, please contact Matthew S. Cox, Section Leader, Licensing, at (623) 393-5753.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on ___June 22, 2021_______

(Date)

Sincerely, Digitally signed by Rash, Rash, Bruce Bruce (Z77439)

DN: cn=Rash, Bruce (Z77439)

(Z77439) Date: 2021.06.22 16:31:57

-07'00' BJR/TNW/mg A member of the STARS Alliance LLC Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek



102-08290-BJR/TNW ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Response to Request for Additional Information for Permanent Extension of Type A and Type C Leak Rate Test Frequencies Page 2



Enclosure:

Response to Request for Additional Information for Permanent Extension of Type A and Type C Leak Rate Test Frequencies cc: S. A. Morris NRC Region IV Regional Administrator S. P. Lingam NRC NRR Project Manager for PVNGS L. N. Merker NRC Senior Resident Inspector for PVNGS B. D. Goretzki Arizona Department of Health Services - Bureau of Radiation Control







Enclosure Response to Request for Additional Information for Permanent Extension of Type A and Type C Leak Rate Test Frequencies





Enclosure Response to Request for Additional Information for Permanent Extension of Type A and Type C Leak Rate Test Frequencies



By letter dated January 22, 2021 (Agencywide Documents Access and Management System Accession No. ML21022A408), Arizona Public Service Company (APS) submitted a license amendment request (LAR) to revise the Technical Specifications (TSs) for Palo Verde Nuclear Generating Station, Units 1, 2, and 3 (Palo Verde). Specifically, the proposed change is a request to revise TS 5.5.16, Containment Leakage Rate Testing Program, to allow the following:

•  Change the existing Type A integrated leakage rate test (ILRT) program test interval to 15 years in accordance with Nuclear Energy Institute (NEI) Topical Report NEI 94-01, Industry Guideline for Implementing Performance-Based Option of [Title 10 of the Code of Federal Regulations (10 CFR)] 10 CFR 50, Appendix J, [Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors], Revision 3-A, and the limitations and conditions specified in NEI 94-01, Revision 2-A.

•  Adopt an extension of the containment isolation valve (CIV) leakage rate testing (Type C) frequency from the 60 months currently permitted by 10 CFR 50, Appendix J, Option B, to 75 months for Type C leakage rate testing of selected components, in accordance with NEI 94-01, Revision 3-A.

•  Adopt the use of American National Standards Institute/American Nuclear Society (ANSI/ANS) 56.8-2002, Containment System Leakage Testing Requirements.

•  Adopt a more conservative allowable test interval extension of nine months, for Type A, Type B and Type C leakage rate tests in accordance with NEI 94-01, Revision 3-A.

The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the application for the subject LAR and concluded that additional information is required for complete evaluation. The NRC staff request is stated first, followed by the APS response.

EMIB-RAI-1 According to current NRC information, the 2012 Edition of the ASME Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code), as incorporated by reference in 10 CFR 50.55a, Codes and standards, is the current OM Code of record for the Inservice Testing (IST) Program at Palo Verde Units 1, 2, 3. ASME OM Code (2012 Edition),

Subsection ISTC, Inservice Testing of Valves in Light-Water Reactor Nuclear Power Plants, Paragraph ISTC-3620, Containment Isolation Valves, specifies that CIVs with a leakage rate requirement based on 10 CFR Part 50, Appendix J, shall be tested in accordance with the Owners 10 CFR Part 50, Appendix J program. Please discuss the basis for not including an alternative request to the ASME OM Code requirements in accordance with 10 CFR 50.55a(z),

Alternatives to codes and standards requirements, as part of the LAR dated January 22, 2021, to extend the leakage rate test interval for the applicable CIVs at Palo Verde.

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Enclosure Response to Request for Additional Information for Permanent Extension of Type A and Type C Leak Rate Test Frequencies



APS Response to EMIB-RAI-1:

The ASME OM Code, Subsection ISTC-3620, Containment Isolation Valves, states the following in its entirety:

Containment isolation valves with a leakage rate requirement based on Appendix J program commitment shall be tested in accordance with the Owners 10 CFR 50, Appendix J program. Containment isolation valves with a leakage requirement based on other functions shall be tested in accordance with para. ISTC-3630. Examples of these other functions are reactor coolant system pressure isolation valves and certain Owner-defined system functions such as inventory preservation, system protection, or flooding protection.

As noted in Subsection ISTC-3620, containment isolation valves with a leakage rate requirement based on Appendix J program commitment shall be tested in accordance with the Owners 10 CFR 50, Appendix J program. APS is not proposing to deviate from the ASME OM Code requirement to test in accordance with the applicable provisions of 10 CFR 50, Appendix J.

The basis for the "...shall be tested in accordance with the Owners 10 CFR 50, Appendix J program" is 10 CFR 50.54(o) as stated in the NRC Safety Evaluation Report for NEI 94-01, Revision 2-A and 3-A, Section 2.0, Regulatory Evaluation:

The regulation at 10 CFR 50.54(o), requires primary reactor containments for water-cooled power reactors to be subject to the requirements of Appendix J to 10 CFR Part 50, "Leakage Rate Testing of Containment of Water Cooled Nuclear Power Plants." Appendix J specifies containment leakage testing requirements, including the types of tests required to ensure the leak-tight integrity of the primary reactor containment and systems and components which penetrate the containment. In addition, Appendix J discusses leakage rate acceptance criteria, test methodology, frequency of testing, and reporting requirements for each type of test.

Including an alternative request to the ASME OM Code requirements in accordance with 10 CFR 50.55a(z), Alternatives to codes and standards requirements, as part of the LAR is not necessary, as testing will continue to be performed in accordance with the applicable provisions of 10 CFR 50, Appendix J, as required by the ASME OM Code.

The PVNGS LAR for permanent extension of Type A and Type C leak rate test frequencies LAR Section 1.0, Summary Description, bullet 2, is replaced with the following clarification:

The licensee proposes an extension of the Type C test interval for PVNGS, Units 1, 2, and

3. Type C tests are currently required to be performed at no longer than 60-month intervals in accordance with NEI 94-01 Revision 0. The proposed amendment and adoption of NEI 94-01 Revision 3-A, would extend the Type C test interval to no longer than 75-months from the last Type C test, with a permissible extension period of 9 months (total of 84 months) for non-routine emergent conditions, based on acceptable performance.

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Enclosure Response to Request for Additional Information for Permanent Extension of Type A and Type C Leak Rate Test Frequencies



EMIB-RAI-2 The LAR, dated January 22, 2021, proposes an extension of the CIV leakage rate testing (Type C) interval from 60 months to 75 months for applicable CIVs at Palo Verde. Please provide a summary description of the performance of the applicable CIVs that supports the proposed extension of the CIV leakage rate testing (Type C) interval.

APS Response to EMIB-RAI-2:

Type C test intervals will be established in accordance with NEI 94-01, Revision 3-A, Section 10.2.3.2, Extended Test Interval, which states that "Test intervals for Type C valves should be determined by a licensee in accordance with Section 11.0." NEI 94-01, Section 11.1, Introduction, states that "Additional programmatic controls are discussed in Section 11.3.2 and shall be considered when the extended test intervals are greater than 60 months." NEI 94-01, Section 11.3.2, Programmatic Controls, describes the process as follows:

If a licensee considers extended test intervals of greater than 60 months for a Type B or a Type C tested component, the review to establish surveillance test intervals should include the additional considerations:

•  As-found Tests In order to provide additional assurance that the increased probability of component leakage is kept to a minimum, and is reasonably within the envelope of industry data, a licensee should consider requiring three successive periodic as-found tests to determine adequate performance.

•  Schedule To minimize any adverse effects of unanticipated random failures, and to increase the likelihood unexpected common-mode failure mechanisms will be identified in a timely manner, a licensee should implement a testing program that ensures components are tested at approximate evenly- distributed intervals across the extended testing interval for valves or groups of valves. A licensee should schedule a portion of the tests during each regularly scheduled outage or on some regular periodic basis, such that some percentage of the components are tested periodically, and all components are tested at the new extended test interval of greater than 60 months.

•  Review A review of the entire process should be performed prior to establishing alternate test intervals under 10CFR50, Appendix J, Option B, including plant-specific performance history, data analysis, establishment of surveillance frequencies, and, if available and applicable, any risk-impact assessment. This review should include adjustments to the program as required, based on expert insight or engineering judgment. Results of the review should be documented.

Without the completion of the above analysis for any Type C tested component, that component will not be eligible for the extension from a 60-month test interval to a 75-month test interval.

As a result, a summary description of the performance of the applicable CIVs that may be subject to the proposed extension of the CIV leakage rate testing (Type C) interval is not available at this time and is not included in this response. The evaluation for the component testing extensions is a process that is based upon performance at the time of consideration for extension. None have yet been formally evaluated for extension at this time.



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