NRC Generic Letter 80-64, Scram Discharge Volume Designs

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GL80064

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555

July 7, 1980

TO ALL OPERATING BOILING WATER REACTORS (BWR's)

Gentlemen:

As you know, the staff has proposed improvements in the scram discharge volume (SDV) designs for BWR control rod drive systems to reduce susceptibility to common cause failures (NUREG-0460). We now request that you amend the Technical Specifications for your facility with respect to control rod drive scram discharge volume capability. The basis for our request is founded in events which have occurred in operating BWR's involving cause failures of SDV limit switches and SDV drain valve operability. In IE Bulletin 80-14 dated June 13, 1980, you were requested to implant procedures and administrative controls to ensure that the SDV is operable during reactor operation. While the function of the bulletin was to effect immediate action with regard to this problem, the proposed Technical Specifications will strengthen the provisions for assuring continued operability of the control rod drive system during reactor operation.

You are requested to propose Technical Specification changes for your facility to provide surveillance requirements for SDV vent and drain valves and LCO/surveillance requirements for RPS and control rod block SDV limit switches. To assist you in preparing your submittal, we have enclosed a copy of Model Technical Specifications which would be sufficient to provider the assurance we seek. These Technical Specifications have proposed by our staff to be incorporated into the next revision of the General Electric Standard Technical Specifications. Applicable changes are marked by vertical lines in the margins. Unchanged pages are included for completeness. Your proposal should use the enclosure as a guide and should include an appropriate Safety Analysis as a basis.

It is requested that you submit your proposed Technical Specifications with the basis within 90 days of receipt of this letter. If you have any questions about this request, please contact your Project Manager.

Sincerely,

Darrell G. Eisenhut, Director Division of Licensing

Enclosure:

Model Technical Specifications