ML030850577
| ML030850577 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 05/06/2002 |
| From: | Allen Hiser Office of Nuclear Reactor Regulation |
| To: | Andruszkiewicz E, Bateman W, Steven Bloom, Chan T, Chang K, Chung J, Stephanie Coffin, Cullen W, Jennifer Davis, Hackett E, Albert Lee, Long S, Kamal Manoly, Marshall M, Anthony Mendiola, Carol Moyer, Naujock D, David Nelson, Pickett D, Sands S, Sheng C, Steingass T, Switzer M, Wetzel B, Wichman K Office of Nuclear Reactor Regulation |
| References | |
| BL-01-001, BL-02-001, FOIA/PA-2003-0018 | |
| Download: ML030850577 (1) | |
Text
File from Steve Long's computer dated 05/06/02 12:56pm named" MESSAGE FOR DAVIS-BESSE ROOT CAUSE MEETING.mlm" From:
Allen Hiser Vflp To:
Andrea Lee; Anthony Mendiola; Beth Wetzel, Bill Bateman; Carol Moyer; Chia-Fu Sheng; David Nelson (HQ-OE); Donald Naujock; Douglas Pickett; Edward Andruszkiewicz; Edwin Hackett; James Davis; Jin Chung; Kamal Manoly; Keith Wichman; Kenneth Chang; Michael Marshall; Michael Switzer; Stephanie Coffin; Stephen Sands; Steven Bloom; Steven Long; Terence Chan; Timothy Steingass; William Cullen Date:
516/02 1:44PM
Subject:
MESSAGE FOR DAVIS-BESSE ROOT CAUSE MEETING For the root cause meeting with Davis-Besse tomorrow, we have prepared the attached
'message points' to help focus and guide our discussions and questions with the licensee. Let me know if you have any comments/questions on these points.
Steve Bloom has asked that questions asked at the meeting be documented by the questioner on 3 x 5 cards that he will provide tomorrow.
Allen
'NRC Message Point' (1) The root cause analysis report provides a plausible scenario of the degradation process(es) that resulted in the cavity at Davis-Besse, but insufficient physical evidence is available to support the description in the report.
(2) Uncertainty in the root cause degradation process(es) will necessitate the use of conservative assumptions in short-term regulatory actions.
(3) FENOC or the industry need to provide physical evidence from metallurgical investigation of the cavity areas and laboratory experimentation to provide understanding of the degradation process(es) that occurred at Davis-Besse.
(4) Reviews of licensee responses to Bulletin 2002-01 have identified no other plants with the type and level of degradation found at Davis-Besse, and the root cause analysis report does not contradict the short-term staff actions, including uncertainties in the report.
(5) The identification of RPV head degradation has opened other safety issues with vessel head penetration (VHP) nozzle cracking beyond the circumferential cracking addressed by Bulletin 2001-01.
(6) A regulatory approach for long-term management of VHP nozzle cracking will be developed by the staff by the end of the year.
Charles Casto; Richard Barrett CC: