27 janvier 2015
Cette perte de circuit unique (sans voie de secours) est survenue 5h46 après l’arrêt d’urgence. Selon la NRC, la pression de contrôle du réacteur aurait été évacuée par les soupapes de décharge ; le refroidissement du réacteur se serait poursuivi normalement ; le niveau d’eau et le refroidissement du cœur auraient été maintenus, alimentés par les groupes diesel...
Type : Fukushima 1 (BWR Mark 1) - Puissance : 2 028 MWTh - Première divergence : 06/1972
Available in english only.
Event Number : 50771
Facility : PILGRIM - State : MA
Unit : [1] - RX Type : [1] GE-3
Event Date : 01/27/2015 - Event Time : 09:48
Emergency Class : NON EMERGENCY 10 CFR Section : 50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
Initial PWR : 0 % Current PWR : 0 %
Event Text
LOSS OF HIGH PRESSURE COOLANT INJECTION
"On Tuesday, January 27, 2015, at 0948 EST, with the Reactor Mode Select Switch (RMSS) in the Shutdown position and Pilgrim Nuclear Power Station (PNPS) at 0% core thermal power, the High Pressure Coolant Injection (HPCI) system was isolated by the main control room operating crew and declared INOPERABLE. HPCI had been in service for reactor pressure control following the automatic reactor scram experienced during winter storm ’Juno’ reported in EN# 50769. It appears there was a malfunction of the HPCI turbine gland seal condenser blower or associated condensate pump. Reactor pressure control was transitioned to the safety relief valves and the reactor cooldown was continued. The plant is stable. The Emergency Diesel Generators are powering the safety related 4KV buses and reactor water level is being maintained by the Reactor Core Isolation Cooling (RCIC) system. HPCI is required to be OPERABLE in accordance with Technical Specification 3.5.C.1. Since HPCI is a single train system, the INOPERABILITY is reportable in accordance with 10CFR50.72(b)(3)(v)(D). The cause of the HPCI malfunction is not known at this time and troubleshooting continues.
"This event had no impact on the health and/or safety of the public.
"The USNRC Senior Resident Inspector has been notified."
Shutdown cooling is in service.
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2015/20150128en.html