NRC Generic Letter 86-13, Potential Inconsistency Between Plant Safety Analyses and Technical Specifications

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WASHINGTON, D. C. 20555

JULY 23, 1986

TO: ALL POWER REACTOR LICENSEES AND APPLICANTS WITH COMBUSTION ENGINEERING AND BABCOCK AND WILCOX PRESSURIZED WATER REACTORS

SUBJECT: POTENTIAL INCONSISTENCY BETWEEN PLANT SAFETY ANALYSES AND TECHNICAL SPECIFICATIONS (Generic Letter 86-13)

The purpose of this letter is to advise you of a potential inconsistency between Technical Specifications and FSAR safety analyses.

In June 1984, Westinghouse informed the staff that they had discovered a potential inconsistency between the Technical Specifications and the safety analyses when a plant is in Mode 3 of operation (hot standby). In a memorandum to the staff dated July 9, 1984, Westinghouse documented the inconsistency (NS-EPR-2935). When a plant is in Mode 3, the Technical Specifications may have required only one reactor coolant pump to be in operation whereas the safety analysis presented in the FSAR (which may have been presented only in terms of a bounding analysis in Mode 2) assumed that two or more reactor coolant pumps were in operation for Mode 3 events.

When Westinghouse reanalyzed the affected events (i.e., steamline break, rod ejection, and bank withdrawal from subcritical) in Mode 3 with only one reactor coolant pump in operation, they concluded that the FSAR analysis remained bounding except for the control rod bank withdrawal from subcritical conditions. For this event, they concluded that the DNBR criteria "may not be met when only one pump is in operation." The Westinghouse plants have evaluated this inconsistency and some plants have proposed Technical Specification revisions or analyzed for the event.

We believe this situation may be equally applicable to CE and B&W designed plants. Representatives of both CE and B&W have notified the NRC that the safety analyses assume more than one reactor coolant pump to be operating, but that no analysis exists which demonstrates directly the adequacy of the current Technical Specifications.

In view of the potential for an inconsistency we encourage you to review your FSAR and Technical Specifications for applicability of the problem for your plant(s). You may wish to examine your Technical Specifications, procedures or other administrative controls to determine if this inconsistency exists in Modes 4&5. Westinghouse plants which have determined that a discrepancy exists (Mode 3) have chosen to remedy this problem by:

(1) proposing revised Technical Specifications to ensure that the plant remains within the analyzed limits of the FSAR, or

(2) carrying out, and including in the next FSAR update, an analysis which bounds the single loop operation and shows that the applicable criteria are not violated. You might wish to consider this approach if the discrepancy exists for your facility.

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This generic letter is for information only and does not involve any reporting requirements. Therefore, no clearance from the Office of Management and Budget is required.

Frank J. Miraglia, Director Division of PWR Licensing-B Office of Nuclear Reactor Regulation