ML20057E594
| ML20057E594 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 10/04/1993 |
| From: | Donnelly P CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-92-01, GL-92-1, NUDOCS 9310120336 | |
| Download: ML20057E594 (2) | |
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Patrick M Donnelly Plant Manager POWERING MICHIGAN'S PROGRESS Big Rock Pomt Nuc6 ear Plant.10269 US-31 North. Char 6evom MI 49720 October 4, 1993 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT - RESPONSE TO A REQUEST FOR ADDITIONAL INFORMATION WITH REGARDS TO GENERIC LETTER (GL) 92-01, REVISION 1, " REACTOR VESSEL STRUCTURAL INTEGRITY, 10 CFR 50.54(f)" - DATED JUNE 30, 1993.
Your Request for Additional Information dated June 30, 1993 with regards tt, Generic letter 92-01 recommended that Big Rock Point provide the following:
1)
The data (initial Charpy Upper Shelf Energy [USE] and chemistry data) for each beltline weld or provide the data and analysis from welds that were fabricated using the same vendor, fabrication time frame, fabrication process, and material specification to demonstrate that the surveillance weld is indeed representative of all beltline welds, and all beltline welds will meet the USE requirements of Appendix G,10 CFR Part 50 (The Big Rock Point response dated February 25, 1993, indicates that the surveillance weld is only representative of the lower shell longitudinal i
weld).
r 2)
If this cannot be provided, then submit an analysis which demonstrates that lower values of USE will provide margins of safety against fracture equivalent to those required by Appendix G of the ASME code.
The information requested in paragraph (1) cannot be provided. Therefore, the Big Rock Point staff is investigating an upper bound analysis (a.k.a. an equivalent margins analysis) for four (4) of the five (5) reactor vessel t
beltline welds to better characterize the required End of Life (EOL) USE.
Currently Combustion Engineering and General Electric are providing proposals for this work. Both companies have Owners Groups which have, or are in the process of, providing upper bound analyses for their members. A reasonable time to complete such an analysis would be on the order of six (6) months to accomodate data retrieval, calculations, reviews, revisions, etc. Proposals are expected to be delivered to the Big Rock Staff by early October,1993.
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BIG ROCK POINT PLANT RAI RESPONSE TO GENERIC LETTER 92-01 October 4,1993 At this time, the Big Rock Point staff believes that current actions associated with responding to Generic letter 92-01 are complete. A supplemental response containing the analysis evaluating USE and the impact on the margins of safety against fracture will be submitted in the second quarter of 1994.
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