ML18313A080
| ML18313A080 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 11/08/2018 |
| From: | Dietrich A Plant Licensing Branch III |
| To: | Levendosky H Indiana & Michigan Electric Co |
| References | |
| L-2018-LLR-0084 | |
| Download: ML18313A080 (3) | |
Text
1 NRR-DMPSPEm Resource From:
Dietrich, Allison Sent:
Thursday, November 8, 2018 12:22 PM To:
Helen L Levendosky Cc:
Joe Tanko (jmtanko@aep.com)
Subject:
D.C. Cook Units 1 and 2 - RAI for RPV Threads in Flange Alternative (EPID L-2018-LLR-0084)
Attachments:
DC Cook RAI RPV Threads in Flange.pdf By letter dated June 14, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18169A148), Indiana Michigan Power Company (the licensee), submitted a request for alternative for the Donald C. Cook Nuclear Plant, Unit Nos. 1 and 2 (CNP), pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Paragraph 50.55a(z)(1). The request is 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 threads in the reactor pressure vessel (RPV) flange.
The U.S. Nuclear Regulatory Commission staff has reviewed your submittal. The staff has determined that additional information is needed in order to complete the review, as described in the attached request for additional information (RAI). The draft RAI was sent to I&M via electronic mail on October 22, 2018. Please respond to this RAI by November 30, 2018.
Please feel free to contact me if you have any questions or concerns.
Sincerely, Allison W. Dietrich, Project Manager Plant Licensing Branch III Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation 301-415-3826
Hearing Identifier:
NRR_DMPS Email Number:
657 Mail Envelope Properties (Allison.Dietrich@nrc.gov20181108122200)
Subject:
D.C. Cook Units 1 and 2 - RAI for RPV Threads in Flange Alternative (EPID L-2018-LLR-0084)
Sent Date:
11/8/2018 12:22:15 PM Received Date:
11/8/2018 12:22:00 PM From:
Dietrich, Allison Created By:
Allison.Dietrich@nrc.gov Recipients:
"Joe Tanko (jmtanko@aep.com)" <jmtanko@aep.com>
Tracking Status: None "Helen L Levendosky" <hllevendosky@aep.com>
Tracking Status: None Post Office:
Files Size Date & Time MESSAGE 1222 11/8/2018 12:22:00 PM DC Cook RAI RPV Threads in Flange.pdf 106579 Options Priority:
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Recipients Received:
REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED ALTERNATIVE REQUEST REACTOR PRESSURE VESSEL THREADS IN FLANGE DONALD C. COOK NUCLEAR PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-315 AND 50-316 By letter dated June 14, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18169A148), Indiana Michigan Power Company (the licensee),
submitted to the U. S. Nuclear Regulatory Commission (NRC) a request for alternative for the Donald C. Cook Nuclear Plant, Unit Nos. 1 and 2 (CNP), pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Paragraph 50.55a(z)(1). The request is 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 threads in the reactor pressure vessel (RPV) flange. Specifically, the licensee proposes to eliminate the volumetric examination requirements of Section XI of the ASME Code threads in the RPV flange (ASME Code,Section XI, Examination Category B-G-1 Pressure Retaining Bolting, Greater than 2 inches (50 mm) in Diameter, Item No. B6.40) for the remainder of the CNP fourth 10-year ISI interval.
The NRC staff has determined that additional information is necessary in order to complete its review.
Request for Additional Information (RAI)-1 In the licensees submittal, under Flaw Tolerance Evaluation, the licensee states that a linear elastic fracture mechanics (LEFM) evaluation consistent with Subsection IWB-3500 of the ASME Code of Record was performed. Based on the NRC staffs evaluation, it appears that the licensees LEFM evaluation was performed consistent with ASME Code Section XI, Appendix G, and Section 6.2.2 of EPRI Report No. 3002010354, dated December 2017.
Confirm that the licensees LEFM evaluation was performed consistent with ASME Code Section XI, Appendix G, or provide specifics related to how the LEFM evaluation was performed.
RAI-2
In the licensees submittal, under Flaw Tolerance Evaluation, the licensee states that the allowable stress intensity factor (K) for preload is 27.5 NVL¥LQ (kilopound per square inch square root inches), based on an ASME Code derived KIC (lower bound fracture toughness) of 53.9 NVL¥LQ and a safety factor of 2. NRC staff calculated an allowable K of 27.0 NVL¥LQ based on an ASME Code derived KIC of 53.9 NVL¥LQ and a safety factor of 2.
Explain the calculation of allowable K for preload.