ML18179A394
| ML18179A394 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 07/18/2018 |
| From: | James Danna Plant Licensing Branch 1 |
| To: | Bryan Hanson Exelon Generation Co, Exelon Nuclear |
| Tobin J, NRR/DORL/LPL1, 415-2328 | |
| References | |
| EPID L-2018-LLR-0056 | |
| Download: ML18179A394 (9) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 July 18, 2018 Mr. Bryan C. Hanson Senior Vice President Exelon Generation Company, LLC President and Chief Nuclear Officer (CNO)
Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3-SAFETY EVALUATION OF RELIEF REQUEST 15R-03 REGARDING THE FIFTH 10-YEAR INTERVAL OF THE INSERVICE INSPECTION PROGRAM (EPID NO. L-2018-LLR-0056)
Dear Mr. Hanson:
By letter dated April 19, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18109A116), Exelon Generation Company, LLC (Exelon, the licensee) submitted Relief Request (RR) 15R-03 to the U.S. Nuclear Regulatory Commission (NRC). Exelon proposed an alternative to certain inservice inspection (ISi) requirements of the American Society of Mechanical Engineers Code for Boiler and Pressure Vessel Code (ASME Code) for the Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3. Specifically, pursuant to Title 10 of the Code of Federal Regulations ( 10 CFR) Section 50.55a(z)( 1), Exelon requested to use certain Boiling Water Reactor Vessel and Internals Project inspection and evaluation guidelines, in lieu of specific ASME Code, Section XI, inspection requirements (i.e.,
vessel interior, interior attachments within beltline region, interior attachments beyond beltline region, and core support structure), on the basis that the alternative provides an acceptable level of quality and safety. The subject relief request is for the fifth 10-year interval of the ISi program at PBAPS, Units 2 and 3, which will begin on January 1, 2019, and is currently scheduled to end on December 31, 2028.
The NRC staff has completed its review of the subject RR as documented in the enclosed safety evaluation (SE). the staff SE concludes that the proposed alternative will provide an acceptable level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(1 ).
Therefore, the NRC staff authorizes the proposed alternative for the fifth 10-year ISi interval at PBAPS, Units 2 and 3.
All other ASME Code requirements for which relief was not specifically requested and approved remain applicable.
B. Hanson If you have any questions concerning this matter, please contact the PBAPS Project Manager, Ms. Jennifer Tobin, at (301) 415-2328 or by e-mail at Jennifer.Tobin@nrc.gov.
Sincerely, o{MMi v~
J:Je~ G. Danna, Chief Plant Licensing Branch LPLI Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-277 and 50-278
Enclosure:
Safety Evaluation cc: via Listserv
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RELIEF REQUEST 15R-03 FOR THE FIFTH 10-YEAR INSERVICE INSPECTION INTERVAL PROGRAM EXELON GENERATION COMPANY, LLC PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3 DOCKET NOS. 50-277 AND 50-278
1.0 INTRODUCTION
By letter dated April 19, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18109A116), Exelon Generation Company, LLC (Exelon, the licensee) submitted Relief Request (RR) 15R-03 to the U.S. Nuclear Regulatory Commission (NRC or the Commission). Exelon proposed an alternative to certain inservice inspection (ISi) requirements of the American Society of Mechanical Engineers Code for Boiler and Pressure Vessel Code (ASME Code), for the Peach Bottom Atomic Power Station (PBAPS), Units 2 and
- 3. Specifically, pursuant to Title 10 of the Code of Federal Regulations ( 10 CFR)
Section 50.55a(z)(1 ), Exelon proposed an alternativa.to certain requirements in ASME Code, Section XI, 2013 Edition with no Addenda. The RR would allow use of certain Boiling Water Reactor Vessel and Internals Project (BWRVIP) inspection and evaluation (l&E) guidelines in lieu of specific ASME Code, Section XI, inspection requirements (i.e., vessel interior, interior attachments within beltline region, interior attachments beyond beltline region, and core support structure), on the basis that the alternative provides an acceptable level of quality and safety.
The subject RR is for the fifth 10-year ISi interval program at PBAPS, Units 2 and 3, which will begin on January 1, 2019, and is currently scheduled to end on December 31, 2028.
2.0 REGULATORY EVALUATION
Section 50.55a(g)(4), "lnservice inspection standards requirement for operating plants," of 10 CFR requires, in part, that ISi of certain 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 the ASME Code, Section XI.
In proposing alternatives, a licensee must demonstrate that the alternatives provide an acceptable level of quality and safety in accordance with 10 CFR 50.55a(z)( 1), or that compliance would result in hardship or unusual difficulty, without a compensating increase in the level of quality and safety in accordance with 10 CFR 50.55a(z)(2).
Enclosure
Based on the above, and subject to the following technical evaluation, the NRC staff finds that regulatory authority exists for the licensee to request, and the Commission to authorize, the alternative requested by the licensee.
3.0 TECHNICAL EVALUATION
3.1 Licensee's Alternative Request 15R-03 Components Affected ASME Code, Section XI, Class 1, Examination Category B-N-1 (interior of reactor vessel), and B-N-2 (welded core support structures and interior attachments to reactor vessels), Item Nos.:
- B13.10 - Vessel Interior
- B13.20 - Interior Attachments within Beltline Region
- B13.30 - Interior Attachments beyond Beltline Region
- B13.40 - Core Support Structure Applicable Code Edition/Addenda The applicable ASME Code is the 2013 Edition with no Addenda, Section XI.
Applicable Code Requirements Section XI of the ASME Code, requires the visual examination (VT) of certain components.
These examinations are included in Table IWB-2500-1, Categories B-N-1 and B-N-2, and are identified with the following item numbers:
- B13.10 - Examine accessible areas of the RV interior each inspection period using a technique, which meets the requirements for a VT-3 examination, as defined in paragraph IWA-2213 of the ASME Code, Section XI
- B13.20 - Examine accessible interior attachment welds within the beltline region each interval using a technique which meets the requirements for a VT-1 examination as defined in paragraph IWA-2211 of the ASME Code, Section XI
- B13.30 - Examine accessible interior attachment welds beyond the beltline region each interval using a technique which meets the requirements for a VT-3 examination, as defined in paragraph IWA-2213 of the ASME Code, Section XI
- B13.40 - Examine accessible surfaces of the core support structures each interval using a technique which meets the requirements for a VT-3 examination, as defined in paragraph IWA-2213 of the ASME Code, Section XI Licensee's Proposed Alternative The licensee proposes to use the BWRVIP l&E guidelines listed below to inspect the affected ASME Code components identified in Table 2 of its submittal in lieu of the requirements of ASME Code, Section XI, for Examination Category B-N-1 and B-N-2, including the examination method, examination volume, frequency, training, successive and additional examinations, flaw evaluations, and reporting. The licensee indicated that not all the components addressed by
these guidelines are ASME Code, Section XI, components. The following BWRVIP guidelines are applicable to this RR:
- BWRVIP-03, Revision 19, "BWR Vessel and Internals Project, Reactor Pressure Vessel and Internals Examination Guidelines"
- BWRVIP-06, Revision 1-A, "BWR Vessel and Internals Project, Safety Assessment of BWR Reactor Internals"
- BWRVIP-18, Revision 2-A, "BWR Core Spray Internals Inspection and Flaw Evaluation Guidelines"
- BWRVIP-26-A, "BWR Top Guide Inspection and Flaw Evaluation Guidelines"
- BWRVIP-47-A, "BWR Lower Plenum Inspection and Flaw Evaluation Guidelines"
- BWRVIP-48-A, "Vessel ID [Internal Diameter] Attachment Weld Inspection and Flaw Evaluation Guidelines"
- BWRVIP-49-A, Instrument Penetration Inspection and Flaw Evaluation Guidelines
- BWRVIP-94NP, Revision 2, "BWR Vessel and Internals Project Program Implementation Guide"
- BWRVIP-138, Revision 1-A, "Updated Jet Pump Beam Inspection and Flaw Evaluation"
- BWRVIP-180, "BWR Vessel and Internals Project, Access Hole Cover Inspection and Flaw Evaluation Guidelines"
- BWRVIP-183-A, "Top Guide Grid Beam Inspection and Flaw Evaluation Guidelines" The licensee stated that any deviations from the referenced BWRVIP guidelines for the duration of the proposed alternative will be appropriately documented and communicated to the NRC per the BWRVIP deviation disposition process.
Licensee's Basis for Proposed Alternative The licensee states that the BWRVIP l&E guidelines recommend specific inspections to identify material degradation that focus on specific and susceptible components, specify appropriate inspection methods capable of identifying known or potential degradation mechanisms, and require reexamination at appropriate intervals. The scope of the BWRVIP guidelines meet or exceed that of ASME Code, Section XI, and in many instances, include components that are not part of the ASME Code, Section XI, requirements.
The BWRVIP executive committee periodically revises the BWRVIP l&E guidelines to include revisions or enhancements in inspection techniques and flaw evaluation methodologies. Where the revised version of a BWRVIP guideline continues to also meet the requirements of the version of the BWRVIP guideline that forms the safety basis for the NRC-authorized proposed alternative to the requirements of 10 CFR 50.55a, it may be implemented. Otherwise, the revised guidelines will only be implemented after NRC approval of the revised BWRVIP guidelines or a plant-specific request for an alternative has been authorized.
The licensee provided with its submittal a current comparison of ASME Code, Section XI, Examination Category B-N-1 and B-N-2 requirements with BWRVIP guidance requirements.
Specific examples were provided that compare the inspection requirements of ASME Code, Section XI, Item Nos. 813.10, 813.20, 813.30, and 813.40 in Table IWB-2500-1, to the inspection requirements in the BWRVIP documents, including inspection methods.
Furthermore, the licensee provided specific examples of how the l&E guidelines from various BWRVIP reports compare to the ASME Code requirements with respect to inspection scope, examination method, and frequency. The licensee states that these comparisons demonstrate that use of these guidelines, as an alternative to the subject ASME Code, Section XI, requirements, provide an acceptable level of quality and safety and will not adversely impact the health and safety of the public.
Duration of Proposed Alternative The proposed alternative would apply to the fifth 10-year ISi interval at PBAPS, which is currently scheduled to begin on January 1, 2019, and end on December 31, 2028.
3.2 NRC Staff Evaluation The NRC staff reviewed the BWRVIP reports referenced in the licensee's submittal to determine if they are acceptable for use in lieu of the ASME Code, Section XI, Examination Category B-N-1 and B-N-2 requirements. Based on its review, the NRC staff found the referenced BWRVIP reports identified in the licensee's submittal to be acceptable for use because the l&E guidelines addressed in these reports would identify degradation in a timely manner and ensures that the integrity of the subject components will be maintained. In addition, PBAPS compliance with the l&E guidelines would provide reasonable assurance that age-related degradation in the subject components will be identified in a timely manner. The details of the NRC staff's assessment of these BWRVIP reports for the purposes of the licensee's proposed alternative is documented below.
Specifically, BWRVIP-06 (Revision 1-A), BWRVIP-18 (Revision 2-A), BWRVIP-26-A, BWRVIP-47-A, BWRVIP-48-A, BWRVIP-49-A, BWRVIP-76 (Revision 1-A), BWRVIP-138 (Revision 1-A), and BWRVIP-183-A, have been previously reviewed and approved by the NRC staff with a corresponding safety evaluation (SE) attached to each of the "-A" reports. Although BWRVIP-25 and BWRVIP-38 do not have a corresponding "-A" report, they were reviewed and approved by the NRC staff by letters dated December 19, 1999, and July 24, 2000, respectively.
During the NRC staff's review of these reports as documented in the respective "-A" report it was determined that degradation can be identified in a timely manner and ensures that the integrity of the subject components will be maintained. Thus, the NRC staff authorizes the use of these BWRVIP l&E guidelines in lieu of ASME Code requirements because the inspection techniques recommended by the BWRVIP meet or exceed the inspection techniques mandated by the ASME Code, Section XI, ISi program and the inspection frequencies are sufficient to detect aging degradation.
The BWRVIP-41, Revision 1, l&E guideline was previously reviewed and approved by the NRC staff with a corresponding SE attached to the "-A" report. This report has since been updated, and the revision identified in the licensee's submittal continues to incorporate adequate l&E guidelines to detect degradation in the subject components in a timely manner and ensures that the integrity of the subject components will be maintained. Thus, the staff authorizes the use of the l&E guidelines in BWRVIP-41, Revision 3, in lieu of ASME Code requirements for the subject components because the inspection techniques recommended by the BWRVIP meet or exceed those mandated by Section XI of the ASME Code, and the inspection frequencies are sufficient to detect aging degradation.
The BWRVIP-180 l&E guideline has not been submitted to the NRC for review and approval; however, based on the NRC staff's review of the report for the purpose of the licensee's proposed alternative, it was noted that the l&E guideline meets or exceed the inspection frequency and techniques mandated by Section XI of the ASME Code, and degradation can be identified in a timely manner, which ensures the integrity of the subject components will be maintained. Thus, the NRC staff authorizes the use of BWRVIP-180 in lieu of ASME Code requirements for the subject components.
In addition, the NRC staff notes that BWRVIP-03 and BWRVIP-94NP, Revision 2, do not contain l&E guidelines for any specific components. Rather, BWRVIP-03, in general: (1) provides an overview of the structure of the BWRVIP, and (2) includes guideline documents that establish protocols to follow in order to gain access to BWRVIP-owned mockups; to perform formal demonstrations of nondestructive examinations (NOE) techniques using BWRVIP mockups; and to perform their own demonstrations of NOE techniques or inspection tooling in an acceptable manner. Furthermore, BWRVIP-94NP, Revision 2, establishes a framework for structuring and strengthening existing BWR vessel and internals programs to ensure consistent application of guidelines by BWRVIP members. The staff notes that these two documents are integral to the implementation of the BWRVIP and the associated l&E guidelines, including those associated with the licensee's submittal.
As part of its evaluation of this proposed alternative, the NRC staff reviewed the results of the licensee's BWRVIP inspection history up until the most recent inspections in 2015 and 2016, for PBAPS, Units 3 and 2, respectively. These results were referenced in the licensee's submittal as supporting information and provide information regarding inspection methods used on the subject components, inspection dates, the inspection results, and corrective actions related to the inspection findings. These results are documented in letters submitted by the Electric Power Research Institute, "Project No. 704- The BWR [boiling-water reactors] Vessel and Internals Inspection Summaries for Fall 2016 Outages," dated June 30, 2017 (ADAMS Accession No. ML17187A190), and "Project No. 704 - BWR Vessel and Internals Inspection Summaries for Fall 2015 Outages," dated June 29, 2016 (ADAMS Accession No. ML16189A217), for PBAPS, Units 2 and 3, respectively. Based on its review of these inspection summaries for PBAPS, the NRC staff finds that the licensee has adequately demonstrated its capability in: (1) identifying the weld flaws (cracking) as well as other relevant indications; (2) taking appropriate corrective actions to ensure that the structural integrity of the component is maintained (i.e., proper repair, if necessary, or flaw evaluation with proper engineering justification); and (3) complying with scope expansion of inspections and subsequent inspections per the applicable BWRVIP reports.
Based on the above considerations, the NRC staff finds that the implementation of the BWRVIP l&E guidelines specified in the licensee's proposed alternative will ensure that the integrity of the subject components will be maintained with an acceptable level of quality and safety.
The NRC staff acknowledges that the BWRVIP Executive Committee periodically revises the guidelines to include enhancements in inspection techniques and flaw evaluation methodologies. While the licensee may choose to implement enhancements described in a revised version of a BWRVIP l&E guideline, the licensee must continue to also meet the requirements of the version of the BWRVIP l&E guideline that forms the basis for the NRC
staffs authorized alternative to the requirements of 10 CFR 50.55a. The licensee may also choose to return to complying with the inspection requirements of the ASME Code of Record for PBAPS.
Thus, the NRC staff authorizes only the BWRVIP l&E guidelines proposed as an alternative in its submittal.
4.0 CONCLUSION
As set forth above, the NRC staff has determined that the proposed alternative, as described in relief request ISR-03, provides an acceptable level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(1 ). Therefore, on the basis of the above determinations, the NRC authorizes the licensee to use the alternative, as proposed in Relief Request ISR-03, for the fifth 10-year ISi interval at PBAPS, Units 2 and 3, which is currently scheduled to begin January 1, 2019, and end on December 31, 2028.
All other ASME BPV Code requirements for which relief was not specifically requested and approved remain applicable, including third-party review by the Authorized Nuclear lnservice Inspector.
Principal Contributor: 0. Yee Date of issuance July 18, 2018
ML18179A394 OFFICE DORL/LPL 1/PM DORL/LPL 1/LA DMLR/MVIB/BC DORL/LPL 1/BC DORL/LPL 1/PM NAME JTobin SRohrer DAIiey* Joanna JTobin DATE 7/2/18 7/2/18 6/20/18 7/17/18 7/18/18