ML20191A025
| ML20191A025 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 07/01/2020 |
| From: | Robert Kuntz NRC/NRR/DORL/LPL3 |
| To: | Loeffler R Northern States Power Company, Minnesota |
| References | |
| L-2020-LLR-0022 | |
| Download: ML20191A025 (3) | |
Text
From:
Kuntz, Robert Sent:
Wednesday, July 1, 2020 7:43 AM To:
Loeffler, Richard A.
Cc:
Scott, Sara
Subject:
DRAFT Request for Additional Information RE: Monticello alternative request RR-016 related to H8, H9, and H 10 weld examinations Mr. Loeffler, By letter dated February 14, 2020, Northern States Power Company, a Minnesota corporation doing business as Xcel Energy (Xcel Energy), submitted a proposed alternative to the inservice inspection (ISI) requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) for the H8, H9, and H10 welds of the core support structure at the Monticello Nuclear Generating Plant (MNGP). The NRC staff has determined that additional information is required to complete its review of the alternative request. Bellow is the NRC staffs draft request for additional information (RAI).
If Xcel Energy requires clarification on the DRAFT RAI contact me to set up a clarification conference with the NRC staff. If no clarification is required this DRAFT RAI becomes an RAI and the NRC staff will expect a response within 30 days of this e-mail.
Robert Kuntz Senior Project Manager NRC/NRR/DORL/LPL3 (301) 415-3733 DRAFT REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ALTERNATIVE NO. RR-016 ASME CODE SECTION XI EXAMINATION CATEGORY B-N-2 H8, H9, H10 WELDS FIFTH TEN-YEAR INSERVICE INSPECTION INTERVAL NORTHERN STATES POWER COMPANY MONTICELLO NUCLEAR GENERATING PLANT DOCKET NO. 50-263 EPID NO. L-2020-LLR-0022
=
Background===
By letter dated February 14, 2020 (ADAMS Accession No. ML20045E769), Northern States Power Company, a Minnesota corporation doing business as Xcel Energy (NSPM, the licensee), submitted a proposed alternative to the inservice inspection (ISI) requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) for the H8, H9, and H10 welds of
the core support structure at the Monticello Nuclear Generating Plant (MNGP). These welds are ASME Code,Section XI Examination Category B-N-2, Welded Core Support Structures and Interior Attachments to Reactor Vessels.
Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Paragraph 50.55a(z)(2), in lieu of performing the required ASME Code successive examinations in ASME Code,Section XI, IWB-2420(b) and (c) for the H8, H9, and H10 welds, alternative request RR-016 proposes to revise the previously authorized alternative in RR-008 (ADAMS Accession No. ML15013A036) for the H8 and H9 welds to remove the 2021 refueling outage from the scope of the authorized alternative. RR-008 also applied a similar alternative to the H10 welds of the core support structure. The alternative requested to use the proposed alternative on the basis that complying with the requirements would result in hardship or unusual difficulty without a compensating increase in quality or safety.
Section 5 Proposed Alternative and Basis for Use of RR-016 (enclosure to the submittal) claims credit for hydrogen water chemistry (HWC) mitigation against crack growth through implementation of Online Noble Metal Chemistry (ONLC). The industry group, Boiling Water Reactor Vessel and Internals Project (BWRVIP), has issued an interim guidance for BWR units that use and credit all forms of HWC by letter dated January 24, 2018 (ADAMS Accession No. ML18033A323). By letter dated July 6, 2018 (ADAMS Accession No. ML18142A019), the NRC staff evaluated this interim guidance as a supplemental safety evaluation of proprietary topical report BWRVIP-62-A (ADAMS Accession No. ML19178A131 PROPRIETARY). The interim guidance states in part that BWR units that use and credit all forms of HWC shall meet the conditions and limitations of BWRVIP-62-A. In the case of plants utilizing ONLC, this means they shall meet the Category 3a NMCA [noble metal chemistry addition] parameters and implementation steps (including platinum loading) of Tables 3-5 and 3-8 [of BWRVIP-62-A].
The alternative requested stated that water chemistry controls will be implemented per the guidelines in BWRVIP-190 BWR Water Chemistry Guidelines and BWRVIP 2019-025 2019 BWR Water Chemistry Guidelines Interim Guidance, but the staff is not clear if BWRVIP-190 and/or BWRVIP 2019-025 have incorporated the interim guidance in the January 24, 2018 letter.
Request:
Confirm that MNGP meets the Category 3a NMCA parameters and implementation steps (including platinum loading) of Tables 3-5 and 3-8 of BWRVIP-62-A per the January 24, 2018 interim guidance.
Hearing Identifier:
NRR_DRMA Email Number:
666 Mail Envelope Properties (SA9PR09MB55501B86ABDC7938109FA03F996C0)
Subject:
DRAFT Request for Additional Information RE: Monticello alternative request RR-016 related to H8, H9, and H 10 weld examinations Sent Date:
7/1/2020 7:43:16 AM Received Date:
7/1/2020 7:43:16 AM From:
Kuntz, Robert Created By:
Robert.Kuntz@nrc.gov Recipients:
"Scott, Sara" <Sara.Scott@xenuclear.com>
Tracking Status: None "Loeffler, Richard A." <Rick.Loeffler@xenuclear.com>
Tracking Status: None Post Office:
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