ML17194A364
| ML17194A364 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 12/15/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17194A363 | List: |
| References | |
| TASK-06-04, TASK-6-4, TASK-RR NUDOCS 8112240209 | |
| Download: ML17194A364 (1) | |
Text
Introduction
.e SAFETY EVALUATION REPORT DRESDEN UNITS 2 AND. 3 OVERRIDE OF CONTAINMENT PURGE ISOLATION ENCLOSURE Instances have been reported at nuclear power plants where the intended automatic closure of the containment purge/ventilation valves during a postulated accident would not have occurred because the safety actuation signals were inadvertently overriden and/or blocked, due to design deficiencies. These instances were determined to constitute an Abnormal Occurrence (#78-5).
As a follow-up action, NRR issued a generic letter requesting each licensee to take certain actions.
Evaluation The enclosed report Electrical, Instrumentation and Control Aspects of the Override of Containment Purge Valve Isolation, 11 (EGG 1183-4199) was prepared for us by EG&G, San Ramon as part of our technical assistance contract program.
The report provides their technical evaluation of the design compliance with NRC provided criteria. The report is applicable to Dresden Units 2 and 3 because they are similar plants.
Conclusion Based upon our review of the contractor's technical report, we conclude that the electrical portion of this topic is not satisfactory in these plants-because the containment ventilation and purge is not isolated automatically by a high radiation signal.
SEP Topic III-12 will address the environmental qualifications of the radiation monitors used to isolate the containment.
The mechanical operability of the containment purge valves is being analyzed separately.
8112240209 811215, PDR ADOCK 05000.237R p
PD1
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