LR-N11-0105, Deviation from BWRVIP-25 Inspection Requirements
| ML11116A105 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 04/14/2011 |
| From: | Jamila Perry Public Service Enterprise Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LR-N11-0105 | |
| Download: ML11116A105 (2) | |
Text
PSEG Nuclear LLC P.O. Box 236, Hancocks Bridge, New Jersey 08038-0236 A..
2011 LR-N 1l-0105 United States Nuclear Regulatory Commission Nuclear LLC Attention: Document Control Desk Washington, D.C. 20555 Hope Creek Generating Station Facility Operation License No. NPF-57 NRC Docket No. 50-354
Subject:
Deviation from BWRVIP-25 Inspection Requirements
Reference:
BWR Vessel and Internals Project, BWR Core Plate Inspection and Flaw Evaluation Guidelines (BWRVIP-25), EPRI Report TR-107284, December 1996 BWRVIP-25 requires that 50% of the core plate rim hold-down bolts of BWR/2-5 plants without repair wedges be examined by enhanced VT-1 from below the core plate (or by UT from above core plate once the technique is developed).
However, it was determined that the bolts cannot be inspected by UT due to configuration issues and it has recently been concluded that an EVT-1 exam does not provide meaningful results. Accordingly, a technical justification for deviation from the BWRVIP guidance was developed.
The technical justification included an analysis that found that the bolting has a relatively low susceptibility to cracking and a very high flaw tolerance. Therefore, postulated flaws would not grow to a size that significantly reduces the bolt preload over the life of the plant. Even if significant cracking did occur in the bolting, redundant structural components will prevent adverse displacement of the core plate. Furthermore, even with the extremely conservative assumptions of failures of both the bolting and the redundant hardware, the Standby Liquid Control (SLC) system could be used to bring the reactor to a safe shutdown.
The BWRVIP is currently working on developing revised guidance for the Core Plate bolts and expects to complete that work, including gaining NRC approval of the revised guidance, by the end of 2015. Given the low likelihood that the function of the core plate will be compromised by bolting failures, there is little risk in postponing inspections of the bolts until such time as the BWRVIP develops revised guidance.
This letter is being transmitted for information only and PSEG Nuclear is not requesting any action from the NRC staff.
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95-2168 REV. 7/99
LR-N11-0105 Document Control Desk Page 2 There are no regulatory commitments contained in this correspondence.
Should you have any questions concerning this letter, please contact Phil Duca, at (856)-339-1640.
Respectfully, ffon.Prry~
Vice President Hope Creek Generating Station Cc:
Mr. W. Dean, Administrator-Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. R. Ennis, Project Manager Salem and Hope Creek U.S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 BlA 11555 Rockville Pike Rockville, MD 20852 USNRC Senior Resident Inspector - Hope Creek (X24)
Jonathan Rowley, NRC U.S. Nuclear Regulatory Commission Mail Stop 0012D20 11555 Rockville Pike Rockville, MD 20852 Matt Mitchell, NRC U.S. Nuclear Regulatory Commission Mail Stop 09H6 11555 Rockville Pike Rockville, MD 20852 P. Mulligan, Manager IV Bureau of Nuclear Engineering PO Box 415 Trenton, NJ 08625 Hope Creek Commitment Tracking Coordinator (H02)