RS-11-065, Withdrawal of Alternative Requirements to NB-4450 on Seal Weld Repairs and Revision to Inservice Inspection Relief Request I3R-19: Alternative Requirements for the Repair of Reactor Vessel Head Penetrations
| ML111170267 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 04/26/2011 |
| From: | Hansen J Exelon Nuclear, Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| I3R-19, NB-4450, RS-11-065 | |
| Download: ML111170267 (2) | |
Text
RS-1 1-065 April 26, 2011 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Byron Station, Unit 1 Facility Operating License No. NPF-37 NRC Docket No. STN 50-454
Subject:
Withdrawal of Alternative Requirements to NB-4450 on Seal Weld Repairs and Revision to Inservice Inspection Relief Request 13R-19: Alternative Requirements for the Repair of Reactor Vessel Head Penetrations
References:
(1) Letter from J. L. Hansen (EGC) to U. S. NRC, "Byron Station Unit 1 Inservice Inspection Relief Request 13R-1 9: Alternative Requirements for the Repair of Reactor Vessel Head Penetrations," dated March 24, 2011 (2) Letter from J. L. Hansen (EGC) to U. S. NRC, "Supplement to Byron Station Unit 1, Inservice Inspection Relief Request 13R-19: Alternative Requirements for the Repair of Reactor Vessel Head Penetrations," dated April 8, 2011 (3) Letter from D. M. Benyak (EGC) to U. S. NRC, "Supplement to Byron Station Unit 1, Inservice Inspection Relief Request 13R-19: Alternative Requirements for the Repair of Reactor Vessel Head Penetrations," dated April 10, 2011 (4) Letter from D. M. Benyak (EGC) to U. S. NRC, "Revised Response to a Request for Additional Information Related to Byron Station Unit 1, Inservice Inspection Relief Request 13R-1 9: Alternative Requirements for the Repair of Reactor Vessel Head Penetrations," dated April 10, 2011 In Reference 1, in accordance with 10 CFR 50.55a, "Codes and standards," paragraph (a)(3)(i),
Exelon Generating Company, LLC (EGC), submitted the Relief Request 13R-1 9 from the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," on the basis that the proposed alternatives would provide an acceptable level of quality and safety.
Specifically, Reference 1 proposed to perform an alternative repair technique using an embedding seal weld methodology on the reactor Vessel Head Penetration housings and J-groove welds of Byron Station, Unit 1. The original request was supplemented by EGC letters that are further described in References 2 and 3, to resolve repairs in penetrations 31, 43, 64 and 76, during the Byron Station, Unit 1, refueling outage 131 R17.
April 26, 2011 U. S. Nuclear Regulatory Commission Page 2 EGC requests withdrawal of the Byron Unit 1 generic portion of 13R-19, (i.e., Reference 1, TAC No. ME5961). 13R-1 9 is hereby revised from generically applicable to each of the Byron Unit 1 Vessel Head Penetration housings, to be specific for the four seal weld repairs completed in 131 R17 on penetrations 31, 43, 64 and 76.
Additionally, EGC requests withdrawal of the provisions in Reference 2 regarding penetrations 31 and 64, and the use of alternative requirements to NB-4450, (i.e., TAC No. ME6061). Code compliant elimination of mechanical discontinuities detected in the seal welds was achieved, and the alternative repair requirements were not used.
There are no new regulatory commitments in this submittal.
If you have any questions about this letter, please contact Mr. Richard W. McIntosh at (630) 657-2816.
of i" L. Hansen Manager - Licensing