ML18116A116
| ML18116A116 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 04/30/2018 |
| From: | Martha Barillas Plant Licensing Branch II |
| To: | Brian Tindell Duke Energy Progress |
| Barillas M DORL/LPL2-2 301-415-2760 | |
| References | |
| EPID L-2018-LLR-0053 | |
| Download: ML18116A116 (5) | |
Text
MEMORANDUM TO:
FROM:
SUBJECT:
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 30, 2018 Brian W. Tindell, Acting Chief Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Martha Barillas, Project Manag~
Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 - VERBAL AUTHORIZATION OF RELIEF REQUEST 14R-18, FOR REACTOR VESSEL CLOSURE HEAD PENETRATION NOZZLE REPAIR TECHNIQUE, INSERVICE INSPECTION PROGRAM - FOURTH 10-YEAR INTERVAL (EPID L-2018-LLR-0053)
By letter dated April 18, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18108A094), as supplemented by letter dated April 20, 2018 (ADAMS Accession Nos. ML18110A292), Duke Energy Progress, LLC (the licensee) submitted Relief Request 14R-18, Reactor Vessel Closure Head Nozzle Repair Technique, lnservice Inspection Program - Fourth 10-Year Interval for Shearon Harris Nuclear Power Plant, Unit 1.
Pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a, the licensee requested the U.S. Nuclear Regulatory Commission (NRG) approval of an alternative for the repair and examination requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) associated with Reactor Vessel Closure Head Penetration Nozzle Number 33.
The licensee proposed to use the alternatives in ASME Code,Section XI, Code Case N-638-6, "Similar and Dissimilar Metal Welding Using Ambient temperature Machine GTAW Temper Bead Technicque," and Code Case N-729-4, "Alternative Examination Requirements for PWR
[Pressurized-Water Reactor] Reactor Vessel Upper Heads With Nozzles Having Pressure-Retaining Partial-Penetration WeldsSection XI, Division 1," to complete the repair procedures and nondestructive evaluation examinations.
The NRG staff reviewed the licensee's submittal and determined that the proposed alternative will provide an acceptable level of quality and safety. During a conference call with the licensee on April 26, 2018, the NRG staff granted a verbal authorization on the use of Relief Request 14R-18, in accordance with 10 GFR 50.55a(z)( 1 ). The script for the verbal authorization is enclosed.
NRG Participants Licensee Partipants B. Tindell T. Hamilton M. Barillas S. McDaniel J. Tsao F.Dean R. Davis J. Terrell S. Rose K. Miller A. Butcavage H. Willetts Docket No. 50-400
Enclosure:
Verbal Authorization Script cc: Listserv
VERBAL AUTHORIZATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION FOR RELIEF REQUEST 14R-18 ALTERNATE REPAIR OF REACTOR VESSEL CLOSURE HEAD PENETRATION NOZZLE DUKE ENERGY PROGRESS, LLC SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 DOCKET NO. 50-400 1.0 Technical Evaluation Read by Robert Davis, Acting Chief of the Component Performance, Non-Destructive Examination, and Testing Branch, Office of Nuclear Reactor Regulation By letter dated April 18, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18108A094), as supplemented by letter dated April 20, 2018 (ADAMS Accession No. ML18110A292), Duke Energy Progress, Inc. (the licensee) requested relief from certain requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, related to the alternate repair of degraded reactor vessel closure head (RVCH) penetration Nozzle Number 33 at Shearon Harris Nuclear Power Plant, Unit 1 (Harris). The licensee submitted relief request 14R-18 for the alternate repair for the fourth 10-year lnservice Inspection interval, which is scheduled to end on September 8, 2027.
The licensee made this request in accordance with the requirements of 1 O CFR 50.55a(z)( 1)
[Title 10, Code of Federal Regulations, Part 50, Section 55a(z)(1)] on the basis that the proposed alternative repair will provide an acceptable level of quality and safety.
In its submittal, the licensee proposed a repair method and examinations. The licensee submitted the following analyses in support of the proposed alternative: the evaluation of a postulated flaw in the J-groove weld that propagates into the reactor vessel head; the evaluation of a postulated flaw at the triple point; the evaluation of loose parts from the degraded J-groove weld falling into the reactor vessel; the corrosion evaluation of the bore of the reactor vessel head penetration exposed to primary coolant; available reinforcement area calculations; and the flaw evaluation of primary water stress corrosion cracking in the remnant nozzle.
The U.S. Nuclear Regulatory Commission (NRC) staff noted that the licensee's evaluation supports an inspection interval of 2.2 effective full-power years. However, the licensee is required to examine all nozzles, including Nozzle Number 33, during every subsequent refueling outage, which is every 18 months, in accordance with ASME Code Case N-729-4 as conditioned in Title 10 of the Code of Federal Regulations, Part 50, Section 55a(g)(6)(ii)(D).
Given that the required inspection interval is less than the interval supported by the licensee's analyses, the NRC finds the licensee's proposed alternative and supporting analyses to be acceptable.
Enclosure The NRC staff finds that the licensee's examination interval of the repaired nozzle is shorter than the design life, therefore, is acceptable to adequately monitor the condition of the repaired nozzle. The NRC staff further finds that the licensee's flaw evaluation provides assurance that should flaws occur, the structural integrity of the repaired nozzle and reactor vessel head will be maintained. The NRC staff determines that the proposed repair will restore the primary system pressure boundary and provide reasonable assurance that the structural integrity of the repaired reactor vessel closure head and repaired Nozzle Number 33 will be maintained for a period of time that exceeds the inspection interval mandated by ASME Code Case N-729-4 as conditioned in 10 CFR 50.55a(g)(6)(ii)(D).
2.0 NRC Staff Conclusion
Read by Brian Tindell, Acting Branch Chief, Plant Licensing Branch 11-2, Office of Nuclear Reactor Regulation As Acting Chief of Plant Licensing Branch 11-2, I concur with the Piping and Head Penetrations Branch's determinations.
The NRC staff concludes that Relief Request 14R-18 will provide an acceptable level of quality and safety for the reactor vessel head and repaired Nozzle Number 33. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(1) and is in compliance with the requirements of the ASME Code,Section XI, ASME Code Case N-638-6 as conditioned in Regulatory Guide 1.147, and ASME Code Case N-729-4, as conditioned by 10 CFR 50.55a(g)(6)(ii)(D). Therefore, as of April 26, 2018, the NRC authorizes the use of Relief Request 14R-18 for Nozzle Number 33 at Shearon Harris Nuclear Power Plant, Unit 1, for the remaining period of the fourth 10-year lnservice Inspection interval, which ends on September 8, 2027.
All other requirements of ASME Code,Section XI, and 10 CFR 50.55a(g)(6)(ii)(D) for which relief was not specifically requested and authorized by the NRC staff remain applicable, including the third party review by the Authorized Nuclear lnservice Inspector.
This verbal authorization does not preclude the NRC staff from asking additional questions and clarifications regarding Relief Request 14R-18 while preparing the subsequent written safety evaluation.
ML18116A116 OFFICE DORL/LPL2-2/PM DORL/LPL2-2/LA NAME MBarillas BClayton DATE 4/26/18 4/26/18 DE/MPHB DORL/LPL2-2/BC DAIiey BTindell 4/26/18 4/27/18