 INES 0 |
UNIT NO. 1 REACTOR SCRAM ON PRM HIGH FLUX |
On 16-7-91, reactor scrammed on PRM high flux. PRM high flux was caused due to spike in reactor pressure up to 74.8 kg/cm2. The reason of reactor pressure spike was the closure of both the stop valves while testing stop valve SV-1P. Malfunctioning of turbine stop valves is suspected to be the reason of its closure while testing. Detailed checks were done and no abnomalies were found.
BASIS FOR RATING: Degradation of defence-in-depth. Table 1 A-IR 0/1, all safety systems/functions were available. Reactor trip proceeded normally. Rating - 0.
DIFFICULTIES IN RATING:
Event date: Tue, 16-07-1991
