INES-event
INES 1

DETERIORATION OF NATURAL CIRCULATION

On 15/09/1993 at 23:35 natural circulation in unit 2 deteriorated according to instruments of the unit control room. Delta T and T began to increase. The necessary surveillance was performed by the personnel. No other anomaly was found. By 03:30 main gate valves of loop 1 were closed, the loop was refilled and vented. After taking loop 1 into operation the natural circulation was restored. During the event max. temperatures of hot leg was 99 deg. C, delta T max. was 50 deg. C. During this event unit 2 was operated under limiting condition 6.1.1.1.2/b of the Operating Technical Specifications.

Location: PAKS-2
Event date: Wed, 15-09-1993
Nuclear event report
Legenda & explanation