ML20010E422
| ML20010E422 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 08/26/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20010E420 | List: |
| References | |
| NUDOCS 8109040109 | |
| Download: ML20010E422 (1) | |
Text
i ENCLOSURE
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SAFETY EVALUATION REPORT BRUNSWICK STEAM ELECTRIC PLANT - UNITS 1 AND 2 OVERRICE OF CONTAINMENT PURGE ISOLATION AND OTHER ENGINEERED SAFETY FEATURES ACTUATION SIGNALS Introductior Instances have been reported at nuclear power plants where the intended automatic closure of containment purge / ventilation valves during a postulated accident would not have occurred because the safety actuation signals were inadvertently oYerridden and/or blocked. These instances were determined to constitute an Abnormal Occurrence (#78-5). As a followup action, NRR issued a generic letter requesting each licensee to take certain actions.
Evaluation The enclosed report (EGG-EA-5198) was prepared for us by EG&G, Idaho, as part of our technical assistance contract program. The report provides tSeir technical evaluation of the design compliance with NRC-provided
<riteria. The report is directly applicable to both Unit 1 and Unit 2, since the design of both Units is the same.
During the course of our review the licensee completed some plant modifi-cations and committed to complete additional modifications during the 1980 refueling outages. The additional modifications were:
(a)circuitmodifi-cations to allow a subsequent isolation signal to the purge / vent valves to defeat an initial manual override action, and (b) installation of keylock switches in place of the previous override switches. Completion of these modifications brings the Units into confonnance with five of the six NRC criteria.
Criterion #3 requires that system-level annunciation to indicate the overridden status be provided when an override is in effect. At Brunswick, only status lights are provided. We require that automatic annunciation of the override of a safety system be provided.
Conclusions Based upon our participation in this technical review and upon our review of the contractor's report, we conclude that the modifications scheduled for the 1980 refueling outages bring the Units into confonnance with five of the six NRC-criteria.
We require that the licensee modify the facilities to provide system-level automatic annunciation of overridden status, whenever an override is active.
We con;ide+ the contractor's report to be a final report, in that no further contractor effort is requ' red for these Units on this subject.
810904o109 810826 PDR ADOCK 05000324 P
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