NRC Generic Letter 78-34, Reactor Vessel Atypical Weld Material

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August 14, 1978

Gentlemen:

RE: REACTOR VESSEL ATYPICAL WELD MATERIAL

This letter confirms our telephone conversation with your staff of August 14, 1978.

The NRC was advised by Babcock & Wilcox (B&W) on August 14, 1978, that a chemical analysis of an archive weldment performed as part of the program for evaluation of reactor vessel material propertied indicated that the nickel and silicon content of the weld material were outside the specified range. It had been determined that the weld filler wire used for that particular weld was atypical.

As of this date, it is not known whether or not this atypical weld wire was used in the manufacture of your reactor vessel. Therefore, we request that you provide the following information to us by Friday, August 18, 1978 (a telecopy of your response is adequate):

1. What interim measures, such as revised pressure/temperature limits, you are taking to ensure reactor vessel integrity in the event that the atypical weld wire was used.

2. Your assessment as to the continued safe operation of your facility based on these interim measures, and

3. Your commitment that these measures will continue in force pending the resolution of this issue.

Your submittal should be three signed originals plus 37 additional copies.

Sincerely,

Branch Chief