ML23270B993
| ML23270B993 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf, River Bend  |
| Issue date: | 09/29/2023 |
| From: | Jennifer Dixon-Herrity NRC/NRR/DORL/LPL4 |
| To: | Gaston R Entergy Services |
| Shared Package | |
| ML23270B990 | List: |
| References | |
| EPID L-2022-LLR-0090 | |
| Download: ML23270B993 (1) | |
Text
OFFICIAL USE ONLY PROPRIETARY INFORMATION OFFICIAL USE ONLY PROPRIETARY INFORMATION September 29, 2023 Mr. Ron Gaston Vice President, Regulatory Assurance Licensing Entergy Services, LLC M-ECH-29 1340 Echelon Parkway Jackson, MS 39213
SUBJECT:
GRAND GULF NUCLEAR STATION, UNIT 1, AND RIVER BEND STATION, UNIT 1 - REQUEST TO UPDATE AMERICAN SOCIETY OF MECHANICAL ENGINEERS BOILER AND PRESSURE VESSEL CODE RELIEF REQUEST SAFETY EVALUATIONS WITH NRC-APPROVED REVISION OF BOILING WATER REACTOR VESSEL AND INTERNALS PROJECT GUIDELINES (GG-ISI-020 AND RBS-ISI-019) (EPID L-2022-LLR-0090)
Dear Mr. Gaston:
By letter dated December 6, 2022, as supplemented by letter dated June 8, 2023, Entergy Operations, Inc. (the licensee) requested a proposed revision to the U.S. Nuclear Regulatory Commission (NRC)-approved Relief Requests (RRs) GG-ISI-020 and RBS-ISI-019 to use latest version of Boiling Water Reactor (BWR) Vessel and Internals Project (BWRVIP) guidelines for Grand Gulf Nuclear Station, Unit 1, and River Bend Station, Unit 1. Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) section 50.55a(z)(1), Acceptable level of quality and safety, the licensee requested to revise these NRC-authorized alternatives to the requirements of 10 CFR 50.55a, Codes and standards, to allow the use of BWRVIP-48, Revision 2, BWR Vessel and Internals Project: Vessel ID [Inside Diameter] Attachment Weld Inspection and Flaw Evaluation Guidelines, as applicable, instead of the currently authorized versions of these guidelines.
The NRC approved an earlier request to revise NRC safety evaluations issued to the licensee concerning the use of the BWRVIP Guidelines in lieu of specific American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) requirements governing inspections of reactor pressure vessel internals. The approval of this alternative was documented in a letter from the NRC to Entergy Operations Inc, Grand Gulf Nuclear Station, Unit 1 and River Bend Station, Unit 1 - Request to update American Society of Mechanical Engineers Code Relief Request Safety Evaluations with NRC-approved Revision of Boiling Water Reactor Vessel and Internals Project Guidelines (EPID L-2020-LLR 0079), dated September 21, 2021.
to this letter contains proprietary information. When separated from Enclosure 1, this document is DECONTROLLED.
OFFICIAL USE ONLY PROPRIETARY INFORMATION OFFICIAL USE ONLY PROPRIETARY INFORMATION Based on information submitted by the licensee, the NRC staff has determined that the proposed RRs will provide an acceptable level of quality and safety. Specifically, the NRC approves the use of the examination guidance for the core spray attachment welds in BWRVIP-48, Revision 2 in NRC-approved RRs GG-ISI-020 and RBS-ISI-019. Accordingly, the NRC staff concludes that the licensee has adequately addressed the regulatory requirements set forth in 10 CFR 50.55a(z)(1).
The NRC approval of the revised inspection guidance for the core spray piping bracket welds addressed in BWRVIP-48, Revision 2, does not imply or infer the NRCs approval of BWRVIP-48, Revision 2 for generic use.
All other requirements of ASME Code,Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components, for which relief was not specifically requested and authorized by the NRC staff remain applicable, including the third-party review by the Authorized Nuclear Inservice Inspector.
Enclosed are the NRC staffs safety evaluations (proprietary and non-proprietary).
If you have any questions, please contact the Project Manager, Siva P. Lingam, at 301-415-1564 or by email to Siva.Lingam@nrc.gov.
Sincerely,
/RA/
Jennifer L. Dixon-Herrity, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-416 and 50-458
Enclosures:
- 1. Safety Evaluation (proprietary)
- 2. Safety Evaluation (non-proprietary) cc: Listserv
OFFICIAL USE ONLY PROPRIETARY INFORMATION OFFICIAL USE ONLY PROPRIETARY INFORMATION ENCLOSURE 2 (NON-PROPRIETARY)
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RELIEF REQUESTS GG-ISI-020 AND RBS-ISI-019 ENTERGY OPERATIONS, INC.
GRAND GULF NUCLEAR STATION, UNIT 1 AND RIVER BEND STATION, UNIT 1 DOCKET NOS. 50-416 AND 50-458 Proprietary information pursuant to Section 2.390 of Title 10 of the Code of Federal Regulations has been redacted from this document.
Redacted information is identified by blank space enclosed within ((double brackets)).
OFFICIAL USE ONLY PROPRIETARY INFORMATION OFFICIAL USE ONLY PROPRIETARY INFORMATION SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUESTS GG-ISI-020 AND RBS-ISI-019 FOR THE USE OF BOILING WATER REACTOR VESSEL AND INTERNALS PROJECT GUIDELINES ENTERGY OPERATIONS, INC.
GRAND GULF NUCLEAR STATION, UNIT 1 RIVER BEND STATION, UNIT 1 DOCKET NOS. 50-416 AND 50-458
1.0 INTRODUCTION
By letter dated December 6, 2022 (Agencywide Documents and Access Management System (ADAMS) Accession No. ML22340A672), as supplemented by letter dated June 8, 2023 (ML23159A230), Entergy Operations, Inc. (Entergy, the licensee) submitted a proposed revision to the U.S. Nuclear Regulatory Commission (NRC)-approved Relief Requests (RRs)
GG-ISI-020 and RBS-ISI-019 to use latest version of Boiling Water Reactor (BWR) Vessel and Internals Project (BWRVIP) guidelines for Grand Gulf Nuclear Station, Unit 1 (Grand Gulf), and River Bend Station, Unit 1 (River Bend). Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) section 50.55a(z)(1), Acceptable level of quality and safety, the licensee requested to revise these NRC-authorized alternatives to the requirements of 10 CFR 50.55a, Codes and standards, to allow the use of BWRVIP-48, Revision 2, BWR Vessel and Internals Project BWR Vessel ID [Inside Diameter] Attachment Weld Inspection and Flaw Evaluation Guidelines, as applicable, instead of the currently authorized versions of these guidelines.
The NRC approved an earlier request to revise NRC safety evaluations issued to Entergy concerning the use of the BWRVIP Guidelines in lieu of specific American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) requirements governing inspections of reactor pressure vessel (RPV) internals. The approval of this alternative was documented in a letter from the NRC to Entergy Operations Inc, Grand Gulf Nuclear Station, Unit 1 and River Bend Station, Unit 1 - Request to update American Society of Mechanical Engineers Code Relief Request Safety Evaluations with NRC-Approved Revision of Boiling Water Reactor Vessel and Internals Project Guidelines (EPID L-2020-LLR 0079), dated September 21, 2021 (ML21258A408).
By a letter dated March 15, 2017 (ML17074A625), the licensee submitted the original RR GG-ISI-020 for Grand Gulf, and by a letter dated February 13, 2018 (ML18045A151), the licensee submitted the original RR RBS-ISI-019 for River Bend.
OFFICIAL USE ONLY PROPRIETARY INFORMATION OFFICIAL USE ONLY PROPRIETARY INFORMATION By letter dated January 23, 2018 (ML18003B126), the NRC staff documented its review and approval of the original submittal of RR GG-ISI-020 for Grand Gulf. Similarly, by letter dated November 16, 2018 (ML18310A013), the NRC staff reviewed and approved the original submittal of RR RBS-ISI-019 for River Bend.
By application dated June 8, 2020 (ML20160A032), as supplemented by letters dated November 9, 2020, April 16, 2021, and August 25, 2021 (ML20314A125, ML21106A216, and ML21237A550, respectively), the licensee submitted an updated revision of RRs GG-ISI-020 and RBS-ISI-019 for Grand Gulf and River Bend.
In the previously NRC-approved RRs GG-ISI-020 and RBS-ISI-019, the NRC staff authorized the licensee to use the core spray attachment weld examination guidelines in BWRVIP-48, Revision 1, as an alternative to requirements in 10 CFR 50.55a and the ASME Code for each of the subject facilities.
After the NRC approval of updated RRs GG-ISI-020 and RBS-ISI-019, the BWR owners group issued BWRVIP-48, Revision 2 in accordance with Nuclear Energy Institute (NEI) 03-08, Guideline for the Management of Materials Issues, Revision 4, Appendix C, Document Screening. The results of the BWRVIP screening evaluation indicated that the revised document may be generically released for implementation by BWRVIP members, without NRC review and approval.
In the submittal dated December 6, 2022, the licensee requested to use the core spray piping attachment weld examination guidelines in BWRVIP-48, Revision 2, in lieu of the currently authorized version of this guideline. Initial NRC approval of BWRVIP-48-A was documented in an NRC approval letter dated July 25, 2005 (ML052130284).
2.0 REGULATORY EVALUATION
The regulations in 10 CFR 50.55a(g)(4), Inservice inspection standards requirement for operating plants, state, in part, that ASME Code Class 1, 2, and 3 components (including supports) must meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components, of the applicable editions and addenda of the ASME Code to the extent practical within the limitations of design, geometry, and materials of construction of the components.
The regulations in 10 CFR 50.55a(z), Alternatives to codes and standards requirements, state, in part, that alternatives to the requirements in paragraphs (b) through (h) of 10 CFR 50.55a may be authorized by the NRC if the licensee demonstrates that: (1) the proposed alternative provides an acceptable level of quality and safety, or (2) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
3.0 NRC TECHNICAL EVALUATION 3.1 Licensees Proposed Alternatives In the current submittal, dated December 6, 2022, the licensee requested the NRC staffs approval to implement a later version of one of the BWRVIP reports that were used in RRs
OFFICIAL USE ONLY PROPRIETARY INFORMATION OFFICIAL USE ONLY PROPRIETARY INFORMATION GG-ISI-020 for Grand Gulf and RBS-ISI-019 for River Bend. This current submittal supplements the original RRs dated March 15, 2017, and February 13, 2018, for Grand Gulf and River Bend units, respectively. Specifically, the licensee requested to use the updated guidance in BWRVIP-48, Revision 2. The NRC staff neither reviewed nor approved Revision 2 of this report.
According to the licensees request, BWRVIP-48, Revision 2 will be used for the fourth inservice inspection (ISI) interval as an alternative to the requirements in 10 CFR 50.55a and the ASME Code,Section XI, at Grand Gulf and River Bend.
3.2 Plant-Specific Evaluation of BWRVIP-48, Revision 2 Guidelines In the licensees supplemental letter dated June 8, 2023, the licensee described technical details of the BWRVIP-48, Revision 2 guidance and additional technical justification for its use.
The proposed alternative in RRs GG-ISI-020 and RBS-ISI-019 is applicable to only the welds attaching the core spray piping bracket to the reactor vessel internal surface as discussed in the supplement. The reinspection guideline for these welds in BWRVIP-48-A is 100 percent of the welds every four refueling cycles (i.e., every 6 or 8 years, depending upon the refueling cycle for the plant). The new guideline for these welds in BWRVIP-48, Revision 2 is 25 percent of the welds every 12 years. While there were other changes in BWRVIP-48, Revision 2, the licensee is requesting only to adopt the new inspection guidance for the core spray piping bracket attachment welds. The licensee stated that core spray bracket weld examinations from 1997 to 2017 resulted in no recordable indications for Grand Gulf. For River Bend, the licensee discovered one recordable indication in 2012. Reinspection in 2014 at River Bend indicated no new indications and no growth of the existing indication.
In Enclosure 4 of the licensees supplemental letter dated June 8, 2023, the licensee provided technical justification for the revised inspection guidelines for the core spray attachment welds.
((
)).
In addition to evaluating past examination results for relevant welds, the licensee described the results of a risk assessment based on ((
)). Examination guidance for high-risk attachment welds remained unchanged. Examination guidance for moderate risk welds, including the core spray attachment welds, were relaxed from 100 percent every four refueling outages to 25 percent every 12 years.
The NRC staff reviewed the updated examination guidance for the core spray attachment welds to BWRVIP-48, Revision 2 for the plant-specific cases of Grand Gulf and River Bend. The NRC staff finds that the plant-specific operating experience of these welds, the fleet-wide operating experience of these welds, and the results of the risk assessment taken together provide appropriate technical justification for the proposed 25 percent sampling approach at Grand Gulf and River Bend.
OFFICIAL USE ONLY PROPRIETARY INFORMATION OFFICIAL USE ONLY PROPRIETARY INFORMATION
4.0 CONCLUSION
As set forth above, the NRC staff has determined that the proposed RRs will provide an acceptable level of quality and safety. Specifically, the NRC approves the use of the examination guidance for the core spray attachment welds in BWRVIP-48, Revision 2 in NRC-approved RRs GG-ISI-020 and RBS-ISI-019. Accordingly, the NRC staff concludes that the licensee has adequately addressed the regulatory requirements set forth in 10 CFR 50.55a(z)(1).
The NRC approval of the revised inspection guidance for the core spray piping bracket welds addressed in BWRVIP-48, Revision 2, does not imply or infer the NRCs approval of BWRVIP-48, Revision 2 for generic use.
All other requirements of ASME Code,Section XI for which relief was not specifically requested and authorized by the NRC staff remain applicable, including the third-party review by the Authorized Nuclear Inservice Inspector.
Principal Contributors: M. Benson, NRR C. Moyer, NRR Date: September 29, 2023