ML19268C171
| ML19268C171 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 11/27/1979 |
| From: | VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | |
| References | |
| NUDOCS 8001030599 | |
| Download: ML19268C171 (1) | |
Text
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Virginia Electric ar.d Power Company i
North Anna Power Station, Unit fl. WPF-4
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l Docket No. 50-338
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jI 24 Hour Reportable Event 11 Written Policw-Up (supplament)
- 12.,/ 27 P d,' 4 9 Event:
ISF Systans Returuing to Non-Safety Mode Upon Reset of Actuation Signal 1.IR/E0 79-141/01T-0 While teviewing the operation of the secondary ventilation system, it was discovered that the system operates in a manner less conservative than that assured in the accident analyses in the uafety analysis report.
Specifically, following the receipt of a Hi-Hi radioactivity signal l
fron the air eject.or radiation s.onitor (RM-SV121) the air tasoval systen diverts air to the containzant (TV-SV102-1 and TV-SV103).
In this condition a containment isolation signal will close these valves.
When the contain ant isolation signal is roast, while the Hi-81 radiation signal is present, these l
valves will reopen, This is not consistant wi!.h FSAR Coc=ent 7.4.
The cause of this discrepancy is not known.
This discrepancy has
[
cet affected the plant and is under review by the engineering staff.
The ij plant is presently in a refueling shutdown.
This event is similar to l'
L12/R0 79-141.
An awndment to LER/RO 79-141 will be submitted within the 14 day reporting requirement of this report.
j i L P. 0 RtiLLY
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