NOC-AE-18003598, Response to Request for Additional Information Request for Relief from the Third 10-Year Interval ISI Program ASME Section Xl Code Requirements for Category B-N-2 and B-N-3 Welds (Relief Request RR-ENG-3-16)

Response to Request for Additional Information Request for Relief from the Third 10-Year Interval ISI Program ASME Section Xl Code Requirements for Category B-N-2 and B-N-3 Welds (Relief Request RR-ENG-3-16)

ML18269A151
Person / Time
Site:	South Texas
Issue date:	09/26/2018
From:	Page M South Texas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-18003598, STI: 34724883
Download: ML18269A151 (4)

Text

Nuclear Operating Company sw's ir~"

South Texas Project Electric Genei-atlng Station P.O. Box 28? Wadsworth, Texas 774S3 September 26, 2018 NOC-AE-18003598 10CFR50.55a D. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 South Texas Project Unit 1 Docket No. STN 50-498 Response to Request for Additional Information Request for Relief from the Third 10-Year Interval ISI Program ASME Section Xl Code Requirements for Category B-N-2 and B-N-3 Welds (Relief Request RR-ENG-3-16)

References:

1) Letter from Michael Page, STP, to Lisa Regner, NRC, "Request for Relief from the Third 10-Year Interval ISI Program ASME Section Xl Code Requirements for Category B-N-2 and B-N-3 Welds (Relief Request RR-ENG-3-16)", June 25, 2018, NOC-AE-18003578, ML18176A085.

2) Email from Lisa Regner, NRC, to Lance Sterling, STP, "Final RAI for South Texas Project RR-ENG-E-16 (L-2018-LLR-0097)", September 12, 2018.

In Reference 1, South Texas Project (STP) submitted a Relief Request to the NRC for STP Unit 1 to extend the Reactor Vessel Inservice Inspection Interval forASME Section Xl Code Requirements for Category B-N-2 Welded Core Support Structures and Interior Attachments to Reactor Vessels and B-N-3 Removable Core Support Structures from 2020 to 2026. By Reference 2, the NRC made a Request for Additional Information. The purpose of this correspondence is to provide a response to the Request for Additional Information related to Reference 2.

There are no commitments in this letter.

If there are any questions, please contact Craig Younger at 361-972-8186.

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lichael Pag<

General Manager of Engineering rjg

Enclosure:

STP Response to Request for Additional Information STI:34724883

NOC-AE-18003598 Page 2 of 2 ec:

(paper copy)

Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 1600 E. Lamar Boulevard Arlington, TX 76011-4511 Lisa M. Regner Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (09E01) 11555RockvillePike Rockville, MD 20852 NRC Resident Inspector U. S. Nuclear Regulatory Commission P. 0. Box 289, Mail Code: MN116 Wadsworth.TX 77483

NOC-AE-18003598 Enclosure Enclosure STP Response to Request for Additional Information

NOC-AE-18003598 Enclosure Page 1 of 1 STP Response to Request for Additional Information NRC Question:

By letter dated June 25, 2018 (Agencywide Document Access and Management System (ADAMS)

Accession No. ML18176A085), STP Nuclear Operating Company (STPNOC, the licensee) requested relief from the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code), Section Xl, to extend the inservice inspection (ISI) interval for Category B-N-2 and B-N-3 examinations for South Texas Project (STP), Unit 1.

Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) paragraph 50.55a(z)(2), the licensee requested an alternate inspection interval for the visual (i.e., VT-3) examinations of Category B-N-2 and B-N-3, on the basis that complying with the specified requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

In its propose alternative, the licensee did not address whether the RPV core barrel is removed for reasons other than to perform the Category B-N-2 and B-N-3 examinations. If there is an opportunity to perform these examinations due to removal of the core barrel for other reasons prior to the next scheduled Category B-A and B-D weld examinations, explain why this was not considered since the hardship to remove the core barrel would be eliminated.

STP Response:

STP considers the hardship of the Category B-N-2 and B-N-3 examinations eliminated if the core barrel is removed from the RPV for reasons other than to solely perform the ASME Section Xl examinations. As part of this alternative, if there is an opportunity to perform examinations due to a removal of the core barrel prior to the next scheduled Category B-A and B-D weld examinations, the ASME BPV Code required VT-3 examinations will be performed on the core support structure and interior reactor vessel attachments (i.e., the Category B-N-2 and B-N-3 components).