RS-09-180, Supplement of Request for Relief from Requirements for Limited Examination of Reactor Vessel Head Penetration Welds in Accordance with 10 CFR 50.55a(a)(3)(i)
| ML093520172 | |
| Person / Time | |
|---|---|
| Site: | Byron  (NPF-066) |
| Issue date: | 12/17/2009 |
| From: | Simpson P Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RS-09-180 | |
| Download: ML093520172 (2) | |
Text
Exelon Generation 4300 Winfield Road Warrenville, IL 60555 RS-09-180 December 17, 2009 www.exeloncorp.com Nuclear U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Byron Station, Unit 2 Facility Operating License No. NPF-66 NRC Docket No. STN 50-455
Subject:
Supplement of Request for Relief from Requirements for Limited Examination of Reactor Vessel Head Penetration Welds in Accordance with 10 CFR 50.55a(a)(3)(i)
References:
(1)
Letter from P. R. Simpson (Exelon Generation Company, LLC) to U. S. NRC, "Requests for Relief for Alternate Examination Frequency Under ASME Code Case N-729-1 and from Requirements for Limited Examination of Reactor Vessel Head Penetration Welds in Accordance with 10 CFR 50.55a(a)(3)(i),"
dated April 2, 2009 (2)
Letter from P. R. Simpson (Exelon Generation Company, LLC) to U. S. NRC, "Supplement to Requests for Relief for Alternate Examination Frequency Under ASME Code Case N-729-1 and from Requirements for Limited Examination of Reactor Vessel Head Penetration Welds in Accordance with 10 CFR 50.55a(a)(3)(i)," dated October 14, 2009 In Reference 1 as supplemented by Reference 2, Exelon Generation Company, LLC (EGC) requested in accordance with 10 CFR 50.55a, "Codes and standards," paragraph (a)(3)(i), NRC approval of relief requests 13R-16 and 13R-17 for Byron Station Unit 2.
Relief request 13R-16 addresses an alternate examination frequency for reactor pressure vessel (RPV) head penetration welds under ASME Code Case N-729-1, and 13R-17 seeks relief for physical configuration and examination equipment limitations precluding the full interrogation of RPV head penetration welds as required in ASME Code Case N-729-1 Table 1.
December 17, 2009 U. S. Nuclear Regulatory Commission Page 2 For 13R-16, in Reference 2 EGC proposed to continue the required volumetric and surface examinations of 10 CFR 50.55a(g)(6)(ii)(D) using an alternative inspection frequency. As a point of clarification, EGC is specifically proposing to perform volumetric and/or surface examinations of all penetrations as specified by Table 1 of ASME Code Case N-729-1 at a frequency of once every second refueling outage or four calendar years, whichever is less, except for Penetration 68, which will have volumetric and surface examinations performed each refueling outage. In addition, bare metal visual examinations of the RPV head, including Penetration 68, will occur each refueling outage.
Additionally, a recent review of ASME Code Case N-729-1 and reactor pressure vessel (RPV) head penetration weld inspection data for Byron Station Unit 2 indicates that the scope of relief request 13R-17 may require expansion. Therefore, EGC is withdrawing relief request 13R-17. EGC plans to resubmit a relief request for this issue in the future.
There are no regulatory commitments contained in this letter. If you have any questions concerning this letter, please contact Ms. Jean M. Smith at (630) 657-2813.
R~ZQ Patrick R. Simpson Manager - Licensing cc:
NRC Regional Administrator - Region III Senior Resident Inspector - Byron Station