ML19317F150
| ML19317F150 | |
| 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 8001080872 | |
| Download: ML19317F150 (2) | |
Text
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JAN 1 0 n74 Docket Nos. 0-269 50-270 and 50-287 Note to Files:
Discussions with Duke Power and RO Region Il regarding the January 5,1974 experience at Unit 2 has resulted in the following additional information and correction of facts.
(See Note to Files 1/10/74).
1.
Duke has isolated and corrected the cause of the switchyard fault which caused the loss of offsite power.
(Faulty shield grounds in cables in blackout logic circuits.)
t 2.
The reactor tripped on high pressure rather than loss-of-flow because of the turbine trip.
Subsequent loss-of-flow resulted from turbine trip causing switch of primary pumps from unit to startup transformer.
3.
Keovee and Lee station power cannot be used to power primary pumps since they are on eteergency buses only.
4.
One primary pump was restarted (after offsite power had been restored) in about an hour after trip.
5.
Probable cause of excessive cooldown rate in natural circulation mode may itave been the fact that Unit 2 steam was being used elsewhere in the plant.
6.
All shutdown systems worked properly including emergency feedwater pump.
(Emergency feedwater controls are on emergency power; main feedwater controls are not.
Both systems are steam driven.)
7.
The cause of the turbine trip is s,cill unknown.
8.
Duke's Nuclear Safety Review Committee, Station Review Committee and B&W have reviewed the indication of the small metslic object in the vessel bottom head and have concluded that it is safe to return to the 75%
power plateau for continued testing. Neutron noise c-alysis will be performed at the 40% power plateau on the way up.
i ffV i 4 8001080 [ ]
. JAN 1 0574
- 9. - At this time RO and L are treating this matter as an unreviewed safety item until Duke provides a report for our review.
L.g.pah1; I. A. Peltier, LPM cc: VAMoore ASchwencer IAPeltier i
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