ML20212F641
| ML20212F641 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee, Cook, 05000000 |
| Issue date: | 12/31/1986 |
| From: | Tripathi R NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Rubin S NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| Shared Package | |
| ML20212F647 | List: |
| References | |
| AEOD-T612, NUDOCS 8701120094 | |
| Download: ML20212F641 (2) | |
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December 31, 1986 AE0D/T612 MEMORANDUM FOR: Stuart D. Rubin, Chief Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data
.THRU:
Peter S. Lam, Chief Reactor Systems Section 2 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data FROM:
Raji Tripathi, Reactor Systems Engineer Reactor Systems Section 2 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data
SUBJECT:
DEGRADATION OF SAFETY SYSTEMS DUE TO COMPONENT MISALIGNMENT AND/0R MISPOSITIONED CONTROL / SELECTOR SWITCHES A technical review report " Degradation of Safety Systems Due to Component Misalignment and/or Mispositioned Control / Selector Switches" is enclosed for your consideration. This study addresses in detail three events at D.C. Cook and one event at Kewaunee where the ability of a safety system to automatically perform its designed function was compromised due to human error. Additionally, we examined 55 similar incidents which occurred at U.S. operating plants between 1981 and 1985. Nearly 91% of these 55 events occurred at PWRs and the rest at BWRs. The systems most affected in these events were the safety injection system, the residual heat removal system and the containment spray system.
The events at D.C. Cook and Kewaunee and other similar occurrences reviewed for the study illustrate that human error can result in the degradation (or complete loss) of a safety system.
If a component misalignment and/or switch mispositioning goes undetected, it could seriously compromise plant safety and, in the absence of timely operator intervention, could delay timely recovery from an accident due to the loss of automatic controls.
The spectrum of events addressed in this report emphasizes the need for appro-priate procedural controls, adequate communications between plant personnel and independent verification of system lineup after maintenance or surveillance b
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. activities. Since occurrences involving loss of system functions due to misaligned components or mispositioned switches seem to be frequent and widespread at the operating reactors, it is suggested that the results of this study be published in Power Reactor Events.
Raji Tripathi, Reactor Systems Engineer Reactor Systems Section 2 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated cc w/ enclosure:
J. K. Heller, Region III R. L. Belson, Region III M. Fairtile, NRR D. Wigginton, NRR M. Beaumont, W C. Brinkman, EE R. Borsum, B&W L. Gifford, GE DISTRIBUTION:
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12/886 DATE :12/d9/86
- 12/z9/86 0FFICIAL RECORD COPY L.