ML19282A395
| ML19282A395 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 02/27/1979 |
| From: | Stello V Office of Nuclear Reactor Regulation |
| To: | Mattson R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19281B343 | List: |
| References | |
| NUDOCS 7905090286 | |
| Download: ML19282A395 (1) | |
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MEMORANDUM FOR:
R. Mattson, Director, Division of Systems Safet;y FROM:
V. Stello, Director, Division of Operating Reactors
SUBJECT:
ABNORMAL OCCURRENCE - DEGRADED ENGINEERED SAFETY SKSTDiS - ARTANSAS HUCLEAR ONE The Commissioners have determined that the September 16,1978 event at the Arkansas Nuclear One station is an Abnormal Occurrence (see ). As part of this action, Coc4fssioner Kennedy requested that the staff inform him of: (1) any generic matters identified by this event, (2) plans for their resolution, and (3) the priorities to be afforded. 00R will coordinate the staff response, which is due to the Commission by 3/16/79.
Three aspects of the Arkansas event appear to be generic:: premature actuation of the recirculation mode of ECCS, reliability of inverter systems to provide electric power for vital instrumentation, degradation of electric power from offsite sources. While 00R will formulate the staff response for the second and third of these, we request that DSS provide an appropriate input regarding the aspect of the premature actuation of ECCS recirculation mode. We would suspect that DSS might want to reconsider: automatic vs manual changeover of ECCS from the injection mdde to recirculation mode, and the advisability of " fail-safe" instrumentation design (which inherently switches toward the recirculation mode upon interruption of electric power) vs " fail-as-is" or " power-on-to-trip" designs.
If DSS could provide its input by March 13, 1979, we believe we can complete the staff response in time to meet the SECY deadline of March 16,1979.
V. Stello, Jr., Director Division of Operating Reactors Office of Nuclear Reactor Regulation cc:
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