ML19317F000
| ML19317F000 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 01/10/1974 |
| From: | Peltier I US ATOMIC ENERGY COMMISSION (AEC) |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8001080699 | |
| Download: ML19317F000 (1) | |
Text
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Docket Nos.
0-269 M 1 0 7974 50-270 and 50-287 Note to Files:
On January 8,1974, Duke informed the LPM of the sequence of events below.
The LPM discussed the situation with the Region II RO inspector who was at the Oconee site on January 8, 1974.
On January 5, 1974, oconee 2 experienced a loss of offsite power caused by a grid fault of some kind.
(Oconee 1 was shut down). For reasons yet unknown the turbine stop valves closed causing a switch from the Unit transformer to the startup transformer which was dead because of the loss of offsite power. Consequently, primary pump power was lost and the reactor cooled down on natural circulation.
(As a consequence of loss-of-flow the reactor tripped.) During the cooldown the Tech Spec cooldown rate limit of 100 F/hr was exceeded indicating that steam generator feedwater rate for this condition is too high.
At the time of the above events Kowee 1 was operating and the Lee Station 100 Kv line to the substation was energized.
Since the substation was out only the underground feeder to the Oconee Station was available for auxiliary power from Kowee (the Keowee overhead line comes through the substation). The Lee Station was available for auxiliary power.
Because Keowee was experiencing overspeed (frequencies >60 cycles per second) and for other reasons yet unknown, Duke elected not to attempt restarting the primary pumps on auxiliary power and the plant remained in the natural circulation mode.
During startup on the weekend, the loose parts monitoring system detected a noise in the reactor vessel lower head during one pump operation. On two pump operation the sound disappears. The noise level was not sufficient to set off the monitoring alarm so the energy level is low.
Experiments in Unit 3 have indicated that the cause of the noise could be a metalic objected about 5/8" in size.
B&W is continuing to analyze the situation.
The plant remains down. Unit 1 is starting up.
,h i
I. A. Peltier, Project Manager Light Water Reactors Br. No. 2-3 Directorate of Licensing cc:
V. Moore A. Schwencer
- 1. Peltier i
i 8001080hN
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