ML20129H844
| ML20129H844 | |
| Person / Time | |
|---|---|
| Issue date: | 05/24/1985 |
| From: | Rubin S NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Seyfrit K NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| Shared Package | |
| ML20129H813 | List: |
| References | |
| REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR AEOD-E508, NUDOCS 8506070674 | |
| Download: ML20129H844 (2) | |
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May 24, 1985 AE0D/E508 MEMORANDUM FOR: Karl V. Seyfrit Chief Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data FRON: Stuart D. Rubin, Chief Reactor Systens Section 1 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data
SUBJECT:
ENGINEERING EVALUATION FOR NUCLEAR PLANT DISTURBANCES CAUSED BY BUMPED ELECTRO-NECHANICAL COHPONENTS Enclosed for your consideration is an Engineering Evaluation Report concerning nuclear plant operating experience involving systen distur-bances caused by bumped electro-mechanical components. The engineering evaluation found that enclosed switches, relays, transmitters and possibly relays in circuit breakers are among the most sensitive electro-mechanical devices in a nuclear plant. A physical disturbance will frequently change the output states of these components. Bumped components have resulted in reactor scrams, safety systen isolations, trips and initiations, and loss of power to safety systens. A reactor scram, caused by bumped reactor protection systes switches, was found to be among the most conmon occur-rences for BWRs. Follow-up investigations of savoral bumped components which tripped or disabled a safety system, found that the component did not appear to meet current seismic qualification standards in all cases.
The data collected indicates that enclosed switches, relays, transmitters and possibly relays in circuit breakers would be mong the most sensitive (i.e., most likely to change state) electro-9:achanical components in a plant during a major seismic disturbance. It is suggested that these h GNC$ N A 46 PDR
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/s Stuart D. Rubin, Chief Reactor Systems Section 1 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data
Enclosure:
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