ML25196A510
| ML25196A510 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 06/09/1975 |
| From: | Kerr W Advisory Committee on Reactor Safeguards |
| To: | Gossick L NRC/EDO |
| References | |
| Download: ML25196A510 (1) | |
Text
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 9 1975 L. V. Gossick Executive Director for Operations SAFE END WELDS ON BEAVER VALLEY, UNIT 1 The Cormnittee's November 20, 1974 operating license report of Beaver Valley, Unit 1, identified a problem with safe ends as quoted:
"Problems have been reported with the safe ends on the Beaver Valley Unit 1 reactor pressure vessel, which were fabricated by a build-up of stainless steel weld metal.
The interfacial region between the nozzle and weld metal ha~ been reported to contain a narrow zone of relatively high hardness, whose safety significance has not been assessed completely.
The Regulatory Staff is evaluating the safe ends to determine whether corrective actions are necessary.
This matter should be resolved in a manner satisfactory to the Regulatory Staff and the ACRS."
The Committee discussed this problem with the NRC Staff during its 177th and 182nd Meetings; it also had the benefit of review of the Staff's Supplement 1 to the Safety Evaluation, issued in May, 1975.
The Cormnittee has reviewed the Staff's technical evaluation of the problem, and the proposed augmented inservice-inspection program for Beaver Valley, Unit 1, and for other reactors with similar safe ends.
The Committee agrees that the Staf*f' s requirements for a more extensive inspection pro-gram are suitably conservative until sufficient additional data are avail-able to establish if there is an enhanced susceptibility to selective corrosion attack.
Since Beaver Valley, Unit 1, is one of several reactors with similar safe ends, the Committee wishes to be kept informed of future Staff requirements or amendments pertaining to augmented inspection programs for the other r~actors and to a better definition of the long term effects of the hard-ened zones in the safe ends.
The Committee wishes to be kept informed of the results of safe-end inspections as those results become available.
W. Kerr, Chairman 87