ML24193A291

Revision to Reactor Vessel Surveillance Capsule Withdrawal Schedule

ML24193A291
Person / Time
Site:	Beaver Valley
Issue date:	07/16/2024
From:	Hipolito Gonzalez NRC/NRR/DORL/LPL1
To:	Blair B Vistra Operations Company
Sreenivas V, NRR/DORL/LPL1
References
EPID L-2024-LRQ-0004
Download: ML24193A291 (1)

Text

July 16, 2024

Barry N. Blair Vistra Operations Company LLC Beaver Valley Power Station Mail Stop P-BV-SSB P.O. Box 4, Route 168 Shippingport, PA 15077-0004

SUBJECT:

BEAVER VALLEY POWER STATION, UNITS 1 AND 2 REVISION TO REACTOR VESSEL SURVEILLANCE CAPSULE WITHDRAWAL SCHEDULE (EPID L-2024-LRQ-0004)

Dear Barry Blair:

By letter dated June 24, 2024 (Agencywide Documents Access and Management System Accession No. ML24176A114), Vistra Operations Company LLC (VistraOps, the licensee) requested revision of the reactor vessel material surveillance capsule withdrawal schedule for the Beaver Valley Power Station (BVPS or Beaver Valley), Units 1 and 2, in accordance with Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of Production and Utilization Facilities, Appendix H, Reactor Vessel Material Surveillance Program Requirements,Section III.B.3, which requires that: (1) withdrawal schedules be submitted, as specified in 10 CFR 50.4, and (2) the proposed schedule must be approved by the Nuclear Regulatory Commission (NRC) prior to implementation.

The NRC staff has reviewed the submittal and concludes that the proposed changes are acceptable and consistent with the intent and requirements of the applicable regulations and guidance found in Appendix H to 10 CFR Part 50, as well as American Society for Testing and Materials Standard E 185-82, Standard Practice for Conducting Surveillance Tests for Light-Water Cooled Nuclear Power Reactor Vessels, dated July 1, 1982. Furthermore, the proposed change meets the guidance in NUREG-1801, Revision 2, Generic Aging Lessons Learned (GALL) Report, dated December 2010. The NRC staffs related safety evaluation is enclosed.

B. Blair

If you have any questions, please contact V Sreenivas, Project Manager at 301-415-2597 or by email to V.Sreenivas@nrc.gov

Sincerely,

Hipólito González, Branch Chief Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Docket Nos. 50-334 and 50-412

Enclosure:

Safety Evaluation

cc: Listserv SAFETY ASSESSMENT BY THE OFFICE OF NUCLEAR REACTOR REGULATION

REQUEST FOR REVISION TO

REACTOR VESSEL MATERIAL SURVEILLANCE PROGRAM

WITHDRAWAL SCHEDULE

VISTRA OPERATIONS COMPANY LLC

BEAVER VALLEY POWER STATION, UNIT NOS. 1 AND 2

DOCKET NOS. 50-334 AND 50-412

EPID L-2024-LLQ-0004

1.0 INTRODUCTION

By letter dated June 24, 2024 (Agencywide Documents Access and Management System Accession No. ML24176A114), Vistra Operations Company LLC (VistraOps, the licensee) requested revision of the reactor vessel material surveillance capsule withdrawal schedule for the Beaver Valley Power Station (BVPS or Beaver Valley), Units 1 and 2, in accordance with Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of Production and Utilization Facilities, Appendix H, Reactor Vessel Material Surveillance Program Requirements,Section III.B.3, which requires that: (1) withdrawal schedules be submitted, as specified in 10 CFR 50.4, and (2) the proposed schedule must be approved by the Nuclear Regulatory Commission (NRC) prior to implementation.

Specifically, the licensee proposed to revise the reactor vessel material surveillance capsule withdrawal schedule at Beaver Valley so that supplemental Surveillance capsule A, which is comprised of previously irradiated BVPS-1 surveillance materials, unirradiated BVPS-1 surveillance materials, and materials from the Fort Calhoun and St. Lucie surveillance programs, and footnote 3 is removed from BVPS-2 Updated Final Safety Analysis Report (UFSAR) Table 5.3-6, Reactor Vessel Material Irradiated Surveillance Schedule.

2.0 REGULATORY EVALUATION

The regulations and guidance relevant to this request are the following.

Section I of Appendix H to 10 CFR Part 50, which states, in part:

The purpose of the [reactor vessel] material surveillance program required by this appendix is to monitor changes in the fracture toughness properties of ferritic materials in the reactor vessel beltline region of light water nuclear power reactors which result from exposure of these materials to neutron irradiation and the thermal environment.

Under the program, fracture toughness test data are obtained from material specimens exposed in surveillance capsules, which are withdrawn periodically from the reactor vessel.

Section III.B.1 of Appendix H to 10 CFR Part 50, which states, in part:

The design of the surveillance program and the withdrawal schedule must meet the requirements of the edition of ASTM E185 [an industry standard by ASTM International, formerly known as American Society for Testing and Materials] that is current on the issue date of the ASME code [American Society of Mechanical Engineers Boiler and Pressure Vessel Code] to which the reactor vessel was purchased; . later editions of ASTM E185 may be used, but including only those editions through 1982.

Section III.B.3 of Appendix H to 10 CFR Part 50, which states:

A proposed withdrawal schedule must be submitted with a technical justification as specified in [10 CFR] 50.4. The proposed schedule must be approved prior to implementation.

U.S. Nuclear Regulatory Commission (NRC, the Commission) Administrative Letter 97-04, NRC Staff Approval for Changes to 10 CFR Part 50, Appendix H, Reactor Vessel Surveillance Specimen Withdrawal Schedules, dated September 30, 1997 (ML031210296), which states, in part:

The Commission found that while 10 CFR Part 50, Appendix H, III.B.3 requires prior NRC approval for all withdrawal schedule c hanges, only certain changes require license amendments as the process to be followed for such approval. Specifically, those changes that do not conform to the ASTM standard referenced in Appendix H (ASTM E-185, Standard Practice for Conducting Surveillance Tests for Light-Water Cooled Nuclear Power Reactor Vessels) will require approval by the license amendment process, whereas changes that conform to the ASTM standard require only staff verification of such conformance.

NUREG-1801, Revision 2, Generic Aging Lessons Learned (GALL) Report, dated December 2010 (ML103490041), which lists generic aging management reviews of systems, structures, and components (SSCs) that may be in the scope of a license renewal application and identifies aging management programs that are determined to be acceptable to manage aging effects of these SSCs.

3.0 TECHNICAL EVALUATION

3.1 Licensees Proposal for BVPS-1 and BVPS-2

The licensee explained that it is requesting approval of a modified reactor vessel surveillance capsule withdrawal schedule for BVPS-2. Specifically, with respect to surveillance capsule A, which is comprised of previously irradiat ed BVPS-1 surveillance materials, unirradiated BVPS-1 surveillance materials, and materials from the Fort Calhoun and St. Lucie surveillance programs, that was installed in the BVPS-2 so that end of license extension fluence values would be accrued more efficiently. As a result, the withdrawal schedule for BVPS-1 surveillance capsule A is tracked on the BVPS-2 surveillance capsule withdrawal schedule.

The current BVPS-2 Updated Final Safety Analysis Report (UFSAR) Table 5.3-6, Reactor Vessel Material Irradiation Surveillance Schedule, includes, in part, surveillance capsule A to be withdrawn at 32 effective full power years (EFPY). The licensee proposes to remove surveillance capsule A from BVPS-2 UFSAR Table 5.3-6, as well as footnote 3, which states:

Supplemental Capsule A contains Beaver Valley Unit 1 initially unirradiated material specimens, as well as previously irradiat ed material specimens from Beaver Valley Unit 1, St. Lucie, and Fort Calhoun. Supplemental Capsule A was inserted in the vacant Capsule V location at the end of Cycle 8. In order to be consistent with the Materials Reliability Program: Coordinated PWR Reacto r Vessel Surveillance Program (CRVSP)

Guidelines (MRP-326) recommendation, Capsule A is to be removed and tested when it reaches a fluence value equivalent to the peak 80-year vessel fluence for Beaver Valley Unit 1. This is expected to occur at approximately 32 FPY.

3.2 NRC Staff Review

Appendix H to 10 CFR Part 50 requires, in part, that the design of the surveillance program and the withdrawal schedule meet the requirements of ASTM E185, Standard Recommended Practice for Conducting Surveillance Tests for Light-Water Cooled Reactor Vessels. The BVPS-1 operating license is scheduled to expire at midnight January 29, 2036 (i.e., the end of the renewed 60-year operating license). Additionally, the BVPS-2 operating license is scheduled to expire at midnight May 27, 2047 (i.e., the end of the renewed 60-year operating license).

As of July 2024, BVPS-1 has withdrawn and tested a total of five surveillance capsules (i.e., Capsules V, U, W, Y, and X). The test results from the latest surveillance capsule (i.e., Capsule X) are documented in WCAP-17896-NP , Revision 0, Analysis of Capsule X from FirstEnergy Nuclear Operating Company Beaver Valley Unit 1 Reactor Vessel Radiation Surveillance Program, (ML14288A393). Per WCAP-17896-NP, Capsule X received a neutron fluence of 5.07 x 10 19 n/cm2 after an irradiation time of 26.6 EFPY.

Consistent with ASTM E185-82, the withdrawal of Capsule X for a 40-year license was completed at a neutron fluence that was not less than once or greater than twice the peak end-of-life vessel fluence (i.e., 3.54 x 10 19 n/cm2). This peak end-of-life neutron fluence for the 40-year license is provided in WCAP-15571-NP, Revision 1, Analysis of Capsule Y from Beaver Valley Unit 1 Reactor Vessel Radiation Surveillance Program (ML082740207). Based on the review of the capsules that have already been withdrawn and tested for BVPS-1, the NRC staff notes that no additional surveillance capsules are required to be withdrawn and tested to satisfy Appendix H to 10 CFR Part 50 and ASTM E185-82 for the original 40-year license.

The NRC staff notes that the projected neutron fluence (E> 1.0 MeV) at the core mid-plane for the BVPS-1 reactor vessel at the end of 60-year renewed license is 5.89 x 10 19 n/cm2 per the current BVPS-1 surveillance capsule withdrawal schedule located in FSAR Table 4.5-3, Reactor Vessel Material Irradiation Surveillance Schedule. This capsule withdrawal schedule was approved by the NRC in a safety eval uation dated July 2, 2018 (ML18164A082). FSAR Table 4.5-3 indicates that Capsule Z will be withdrawn after 39 EFPY, which corresponds to the peak vessel fluence at the end of the 60-year renewed license. Additionally, the NRC concluded, in part, in its safety evaluation dated July 2, 2018, that the surveillance capsule withdrawal schedule for BVPS-1, which includes Capsule Z, meets the requirements in Appendix H to 10 CFR Part 50, is in compliance with ASTM E185-82, and is consistent with the recommendations of GALL Report Section XI.M31.

As discussed above, the licensee has fulfilled its material surveillance requirements for the original 40-year license with the withdrawal and testing of Capsules V, U, W, Y, and X, and the approved BVPS-1 capsule withdrawal schedule includes the withdrawal and testing of Capsule Z. The NRC staff noted that withdrawal and testing of Capsule Z fulfills the

recommendations in GALL Report Section XI.M31 and ensures adequate aging management of the reactor vessel for irradiation embrittlement during the 60-year renewed license. Based on the review of the five capsules that have already been withdrawn and tested for BVPS-1, and with the planned withdrawal and testing of Capsule Z in accordance with its approved capsule withdrawal schedule, the NRC staff notes that no additional surveillance capsules, including the mechanical testing and reporting of results for supplemental surveillance capsule A, are required to satisfy Appendix H to 10 CFR Part 50 and ASTM E185-82 for the original 40-year license or the 60-year renewed license.

The licensee has already fulfilled its reactor vessel material surveillance requirements for BVPS-1 for the original operating license period (i.e., 40 years), and will be withdrawing Capsule Z consistent its approved surveillance capsule withdrawal schedule located in FSAR Table 4.5-3, Reactor Vessel Material Irradiation Surveillance Schedule, which address the recommendations in NUREG-1801, Revision 2, for its current operating license through 60-years of operation. The NRC staff notes that a report containing the test results for supplemental Surveillance capsule Z must be reported to the NRC within 18 months of the capsule withdrawal in accordance with Section IV.A of Appendix H to 10 CFR Part 50.

Based on its review of the capsules that have already been withdrawn and tested for BVPS-1, and with the planned withdrawal and testing of Capsule Z (per UFSAR Table 4.5-3 BVPS-1), the NRC staff finds the proposed withdrawal schedule to remove Surveillance capsule A and footnote 3 from UFSAR Table 5.3-6 for BVPS-2, will not impact the licensees ability:

to address the underlying purpose of Appendix H to 10 CFR Part 50 (i.e., monitor changes in the fracture toughness properties of the reactor pressure vessel) and to demonstrate compliance with Appendix H to 10 CFR Part 50 and ASTM E185-82 for the continued plant operation of BVPS-1 through the 60-year renewed license.

Therefore, the NRC staff finds that the licensees proposed withdrawal schedule for surveillance capsule A and footnote 3 to be removed from UFSAR Table 5.3-6 for BVPS-2 is acceptable.

The NRC staff concludes that the withdrawal and testing of Surveillance capsule A is not necessary for compliance to the requirements of the reactor vessel material surveillance program for the current license period at BVPS-1.

4.0 CONCLUSION

Based on the above evaluation, the NRC staff conc ludes that the proposed surveillance capsule withdrawal schedule for Beaver Valley Power Station to remove surveillance capsule A and foot note 4 from UFSAR Table 5.3-6 for BVPS-2 is acceptable; therefore, the NRC staff approves this surveillance capsule withdrawal schedule.

Principal Contributors: O. Yee, NRR

Date: July 16, 2024

ML24193A291 NRR-106 OFFICE NRR/DORL/LPL1/PM NRR/DORL/LPL1/LA NRR/DNRL/NVIB/BC NAME VSreenivas KZeleznock ABuford DATE 07/11/2024 07/15/2024 07/10/2024 OFFICE NRR/DORL/LPL1/BC NAME HGonzález DATE 07/16/2024