ML20111A279
| ML20111A279 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 04/20/2020 |
| From: | Ellen Brown NRC/NRR/DORL/LPL2-2 |
| To: | Hess R, Mihalakea S Florida Power & Light Co |
| References | |
| L-2020-LLR-0040 | |
| Download: ML20111A279 (5) | |
Text
From: Brown, Eva Sent: Monday, April 20, 2020 11:45 AM To: Mihalakea, Stavroula; Hess, Robert Cc: Shoop, Undine
Subject:
VERBAL REQUEST: Turkey Point Unit 3 - Verbal Relief Related to 'B' Component Cooling Water Return Header (EPID L-2020-LLR-0040)
Attachments: Turkey Point Relief Request No. 6 Draft Verbal Authorization Script Final 1100 200420.pdf
- Stavy, Please find attached documentation of the verbal relief that NRC provided the morning of April 20, 2020. This correspondence and attachment will be made publicly available.
Please note that the verbal authorization was deemed appropriate due to the following being confirmed:
- The proposed alternative was in writing and all information that the NRC staff requires to write the safety evaluation (SE) was received by the NRC Document Control Desk and docketed.
- The need for the verbal authorization, and circumstances leading to such need, were clearly provided in the submittal.
- The NRC staff has completed its review and determined that the proposed alternative is technically justified, and the circumstances supporting the need for verbal approval are reasonable.
- The verbal authorization was provided because the NRC staff simply did not have enough time to produce the SE documenting its review.
- All technical information needed for the technical branch to write an SE has been provided on the docket.
- The technical branch chief and the DORL branch chief agreed to the verbal authorization.
Should you have any questions, comments, or clarifications, please feel free to contact me.
Eva Brown Senior Project Manager, Turkey Point Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Telephone: (301) 415-2315 Fax: (301) 415-1222
Hearing Identifier: NRR_DRMA Email Number: 538 Mail Envelope Properties (MN2PR09MB5274CD5060D4A5DA3A3BD7B8EFD40)
Subject:
VERBAL REQUEST: Turkey Point Unit 3 - Verbal Relief Related to 'B' Component Cooling Water Return Header (EPID L-2020-LLR-0040)
Sent Date: 4/20/2020 11:45:11 AM Received Date: 4/20/2020 11:45:00 AM From: Brown, Eva Created By: Eva.Brown@nrc.gov Recipients:
"Shoop, Undine" <Undine.Shoop@nrc.gov>
Tracking Status: None "Mihalakea, Stavroula" <Stavroula.Mihalakea@fpl.com>
Tracking Status: None "Hess, Robert" <Robert.Hess@fpl.com>
Tracking Status: None Post Office: MN2PR09MB5274.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1496 4/20/2020 11:45:00 AM Turkey Point Relief Request No. 6 Draft Verbal Authorization Script Final 1100 200420.pdf 150179 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:
VERBAL AUTHORIZATION BY THE OFFICE NUCLEAR REGULATION RELIEF REQUEST NO. 6 COMPONENT COOLING WATER WELDED REPAIRS FOR EXTERNAL CORROSION TURKEY POINT, UNIT NO. 3 FLORIDA POWER & LIGHT COMPANY DOCKET NO. 50-250 APRIL 20, 2020 Technical Evaluation read by Matthew Mitchell, Chief of the Piping and Head Penetration Branch, Office of Nuclear Reactor Regulation By letter dated March 30, 2020 as superceded by a letter dated April 13 and supplemented by publicly-available letters dated April 15 and 19, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML20090K520, ML20104B999, ML20106F200, and ML20110A000, respectively), Florida Power & Light Company (the licensee) proposed an alternative to requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, IWA-4421 and Title10 of the Code of Federal Regulations (10 CFR) 50.55a(b)(2)(xxv), at Turkey Point, Unit 3 (Turkey Point).
Pursuant to 10 CFR 50.55a(z)(2), the licensee submitted Relief Request No. 6 for a modification in accordance with Section XI, IWA-4340 to repair certain sections of the degraded Turkey Point Component Cooling Water (CCW) return piping by installing a proprietary repair device without removing the sections of degraded piping. The licensee has determined that removing the degraded portions of piping in accordance with IWA-4421 prior to performing a repair/replacement activity represents a hardship or unusual difficulty without a compensating increase in the level of quality and safety. The hardship cited by the licensee deals with the inability/difficulties associated with the isolation of the CCW system to allow piping removal and replacement by welding.
The piping degradation for the Turkey Point Train B CCW return piping has been characterized as a through-wall leak caused by external corrosion of the piping. The licensee proposed the installation of a modification/repair in accordance with ASME Section XI, IWA-4340 to be installed around the circumference of the degraded piping without the removal of the degraded area. The modification/repair proposed by the licensee is to install an encapsulation which is a welded proprietary repair device, PMCap Restoration Method - US Patent 6,860,297, hereafter referred to as PMCap, over the defect in the subject piping.
The licensee proposed that during installation of the proposed encapsulation welding will be performed in accordance with the FPL Welding Control Manual. The licensee stated that the PMCap encapsulation will satisfy the design requirements of ASME/ANSI Code, B31.1-1973, the original construction code of the Turkey Point CCW piping. The PMCap replaces the degraded pressure boundary material and provides structural integrity of the piping system, such that it no longer relies on the degraded area, including any projected future corrosion.
The licensee performed a flaw evaluation in accordance with NRC-approved ASME Code Case N-513-3, Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1. The N-513-3 evaluation was performed to validate the structural integrity of the as found condition and continued system operation until the modification was installed. The modification includes the application of aluminum oxide thermal spray coating on the exterior and an improved boot seal to prevent further degradation of the exterior of the piping. The inside surface will be covered by CCW which will provide corrosion inhibiting chemistry into the area of concern. The licensee proposed that the corrosion mitigation steps taken as part of the modifications negate the requirement for future UT thickness examinations described in N-513-3.
The licensee stated that future Inservice Inspections (ISI) would be performed in accordance with Section XI, Table IWD-2500-1 for Examination Category D-A components, which requires visual examination of attachment welds.
Based on the review of the information provided above, the NRC staff finds that (1) there is reasonable assurance of adequate protection based on the PMCap encapsulation will satisfy the design requirements of the original construction code of the Turkey Point CCW piping, (2) there is reasonable assurance of adequate protection based on the N-513-3 evaluation performed to validate the structural integrity of the as found condition, (3) there is reasonable assurance of adequate protection based mitigation measures taken to prevent further degradation of the piping, (4) there is reasonable assurance of adequate protection based future ISI exams being performed in accordance with Examination Category D-A items, and (5) the licensees hardship justification is acceptable.
Therefore, the NRC finds that Relief Request No. 6 will provide reasonable assurance that structural integrity of the subject CCW piping and its intended safety function will be maintained in that the piping has been restored to compliance with the original construction code.
Authorization read by Undine Shoop, Chief of the Plant Licensing Branch II-2, Office of Nuclear Reactor Regulation As Chief of the Plant Licensing Branch II-2, Office of Nuclear Reactor Regulation, I agree with the conclusions of the Piping and Head Penetration Branch.
The NRC staff concludes that the proposed alternative of the installation of the PMCap encapsulation meets the requirements of the original construction code of the Turkey Point Unit 3 CCW piping. The NRC staff finds that complying with the requirements of the ASME Code,Section XI would result in hardship or unusual difficulty without a compensating increase in the 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)(2).
Therefore, effective April 20, 2020, the NRC authorizes the use of the proposed Relief Request No. 6, at Turkey Point, Unit 3.
All other requirements in ASME Code,Section XI for which relief was not specifically requested and approved in this relief request remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.
This verbal authorization does not preclude the NRC staff from asking additional clarification questions regarding the proposed alternative while subsequently preparing the written safety evaluation.