ML20197A212

Response to Request for Additional Information for Proposed Alternative to American Society of Mechanical Engineers Boiler and Pressure Vessel Code IR-056, Revision 3

ML20197A212
Person / Time
Site:	Perry
Issue date:	07/15/2020
From:	Payne F Energy Harbor Nuclear Corp
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EPID L-2020-LLR-0004
Download: ML20197A212 (6)

Text

energy harbor Perry Nuclear Power Plant 10 Center Road P.O. Box 97 Perry, Ohio 44081 Frank R. Payne 440-280-5382 Site Vice President, Perry Nuclear July 15, 2020 L-20-182 10 CFR 50.55a ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

Perry Nuclear Power Plant Docket No. 50-440, License No. NPF-58 Response to Request for Additional Information for Proposed Alternative to American Society of Mechanical Engineers Boiler and Pressure Vessel Code IR-056, Revision 3

{EPID L-2020-LLR-0004)

By letter dated January 6, 2020 (Agencywide Documents Access and Management System (ADAMS), Accession No. ML20006D984), Nuclear Regulatory Commission (NRC) approval was requested for proposed alternatives to the American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel Code, for the fourth 10-year in service inspection interval for the Perry Nuclear Power Plant.

By electronic mail dated June 15, 2020, the NRC requested additional information to complete its review of Proposed Alternative Request No. IR-056, Revision 3. The Energy Harbor Nuclear Corp. response to this request is attached.

There are no regulatory commitments contained in this submittal. If there are any questions or if additional information is required, please contact Mr. Phil H. Lashley, Acting Manager- Nuclear Licensing and Regulatory Affairs, at (330) 696-7208.

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Perry Nuclear Power Plant L-20-182 Page 2

Attachment:

Response to Request for Additional Information cc: NRC Region III Administrator NRC Resident Inspector NRC Project Manager

Attachment L-20-182 Response to Request for Additional Information Page 1 of 4 By electronic mail dated June 15, 2020, the Nuclear Regulatory Commission (NRC) staff requested additional information to complete its review of Proposed Alternative Request No. IR-056, Revision 3. The responses for the Perry Nuclear Power Plant (PNPP) are provided below. The NRC staff request is presented in bold type, followed by Energy Harbor Nuclear Corp.s response.

RAI-NVIB-01 (IR-056)

In the January 6, 2020 application, the licensee submittal of the proposed alternative makes a reference to BWRVIP-47-A which has an unresolved commitment. Given that the BWRVIP has not yet provided revised inspection guidance, the NRC staff requests that the licensee discuss the following issues that are related to the inspections of the lower plenum components at PNPP.

Please confirm the following:

(a) The NRC staff noted that BWRVIP-47-A does not include any re-inspection criteria for the reactor vessel internal components that are categorized under B-N-1, No. B13.10 Category, and, B-N-2, No. B13.40 Category.

Therefore, the staff requests that the licensee provide information on the type of inspections and the frequencies of inspections that have been performed to date on the aforementioned components. Furthermore, the licensee is requested to address the re-inspection frequencies and type of inspection techniques to be used on these components. In case the afore-components are not to be inspected in the current and subsequent intervals, discuss the impact of failure of these lower plenum components on the integrity of the reactor vessel internals.

Currently there is no re-inspection criteria outlined in the NRC approved BWRVIP-47-A document, and this remains an open item for the BWRVIP Program to address. BWRVIP-47-A requires owners to perform one-time baseline inspections on the lower plenum components covered by the report, which Energy Harbor Nuclear Corp. completed in refueling outages between 1999 and 2007. This satisfied the 12-year baseline requirement. While no re-inspections are specified, Section 3.2.5 of the BWRVIP-47-A report discusses performing visual inspections of components to the extent practical when access to the lower plenum is obtained. This methodology has been incorporated into Energy Harbor Nuclear Corp. BWRVIP program documents.

Attachment L-20-182 Page 2 of 4 For ASME Section XI Category B-N-1, Item B13.10 and Category B-N-2, Item 13.40 components, the code requires VT-3 visual examinations on accessible areas and surfaces, and for B13.10 components specifically, accessible areas is defined to mean only the spaces above and below the reactor core that are made accessible for examination by removal of components during normal refueling outages. Further, ASME Section XI code interpretations XI-1-95-28 and XI-1-92-46 offer additional clarification on the intent of the examination requirements specified for B-N-1 and B-N-2 category components. Interpretation XI-1-95-28 states that VT-3 visual examinations are not required to be performed in spaces below the core even when they are made accessible by removal of components, if the components being removed are not normally removed during refueling outages. Interpretation XI-1-92-46 states that it is not required that owners disassemble portions of the reactor vessel internals of a boiling water reactor to provide access below the reactor core, which is not accessible during normal refueling outages, in order to perform the visual examination on the core support structure under ASME Section XI Category B-N-2. Therefore, Section 3.2.5 of BWRVIP-47-A, which encourages the performance of visual examinations on lower plenum components whenever they become accessible, goes above and beyond the requirements listed in the ASME Section XI code and applicable interpretations. In accordance with the BWRVIP report, Energy Harbor Nuclear Corp. performs such inspections when the opportunity exists.

Energy Harbor Nuclear Corp. recognizes that specific re-inspection criteria remains an open commitment between the BWRVIP Program and the NRC, however, full compliance with the NRC approved BWRVIP-47-A report is maintained at this time. Energy Harbor Nuclear Corp. continues to monitor for further guidance developed by the BWRVIP. Additionally, the impact of possible failures of lower plenum components on reactor vessel internals is addressed in the BWRVIP-47-A report itself, largely on a component-by-component basis.

No further assessments have been performed.

(b) The staff requests that the licensee confirm whether there are any additional ASME Code Section XI reactor vessel internals components (included in BWRVIP-47-A report) binned under B-N-1 and B-N-2 Categories at PNPP. If so, please provide the inspection techniques, and inspection frequencies for these components at PNPP.

Energy Harbor Nuclear Corp. confirms that it has no additional ASME Section XI reactor vessel internals components (included in BWRVIP-47-A report) binned under B-N-1 and B-N-2 categories.

Attachment L-20-182 Page 3 of 4 Other B-N-1 and B-N-2 components are covered by different BWRVIP reports such as BWRVIP-76 and BWRVIP-25.

RAI-NVIB-02 (IR-056)

In the January 6, 2020, submittal, the licensee states that:

The BWRVIP executive committee periodically revises the BWRVIP guidelines to address industry operating experience, include enhancements to inspection techniques and add or adjust flaw evaluation methodologies. Where the revised version of a BWRVIP inspection guideline continues to also meet the requirements of the version of the BWRVIP inspection 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 has been approved.

The NRC staff has generically approved BWRVIP guidelines through the topical report process. However, in accordance with 10 CFR 50.55a, "Codes and standards," licensees must obtain plant-specific NRC approval to use the BWRVIP guidelines as an alternative to the ASME Code requirements. The NRC staff notes that plant-specific use of revisions of BWRVIP Topical Reports that NRC staff have not yet seen nor approved, pursuant to 10 CFR 50.55a(z), require the licensee to submit for NRC approval.

Please clarify how the BWRVIP inspection guidelines will be implemented at PNPP. Specifically, please describe the process for determining which revised BWRVIP inspection guidelines will be submitted to NRC approval prior to plant-specific adoption.

Energy Harbor Nuclear Corp. outlined in the January 6, 2020, submittal the specific BWRVIP reports that are being requested for approval as alternatives to the ASME Section XI Code requirements. Once the request is approved, Energy Harbor Nuclear Corp. initially implements and follows the inspection guidelines as written in the specified reports, including the revision number. In the event that subsequent revisions are made by the BWRVIP to reports specified in the request, Energy Harbor Nuclear Corp. evaluates the nature of the revision and determines whether or not any changes were made to the requirements, guidelines, or scope of the report. If revisions were made that encourage or allow less conservative inspection frequencies, smaller inspection populations, and so forth, then subsequent relief is sought from the NRC to

Attachment L-20-182 Page 4 of 4 implement said guidelines if Energy Harbor Nuclear Corp. desires to implement them.

If the revised guidelines are not used, the previous BWRVIP report outlined in the most recently approved request continues to govern. Alternatively, if revisions are made by the BWRVIP to reports specified in the request that do not change the requirements, guidelines, or scope of the report, are non-technical in nature, and are documented as such in the report itself, Energy Harbor Nuclear Corp. could choose to adopt said revision of the report or allow the previously approved revision to govern. Energy Harbor Nuclear Corp. would adopt the new revision of the report for programmatic purposes only in this case, simply to maintain the BWRVIP and inservice inspection programs as current as possible. Under no circumstances would less conservative BWRVIP reports be implemented by Energy Harbor Nuclear Corp. at PNPP without explicit approval from the NRC.