10 janvier 2018
Ce signal a enclenché l’activation du système de protection du réacteur (RPS). Des investigations sont menées pour déterminer l’origine de la défaillance de la voie 2 de la vanne de contrôle de la turbine, sachant que la voie 3 était fermée et hors service. Toutes les barres de contrôle se sont correctement insérées dans le cœur. Les vannes d’isolement de la vapeur principale sont restées ouvertes avec les vannes de dérivation de la vapeur qui contrôlent la pression du cœur. Les pompes d’alimentation en eau sont restées en service afin de maintenir le niveau d’eau. Tous les systèmes de confinement ont été correctement activés dès réception de leur signal de commande.
Type : Fukushima 1 (BWR Mark 1) - Puissance : 3 458 MWrh - Première divergence : 8 / 1976 -
Available in english only
Event Number : 53162
Facility : BROWNS FERRY
State : AL - Unit : [3] - RX Type : [3] GE-4
Event Date : 01/10/2018 - Event Time : 09:28 [CST]
Last Update Date : 01/10/2018
Emergency Class : NON EMERGENCY
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL - 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Initial PWR : 73 % Current PWR : 0 %
Event Text
AUTOMATIC REACTOR SCRAM DUE TO TURBINE CONTROL VALVE FAST CLOSURE SCRAM SIGNAL
"At 0928 CST on January 10, 2018, the Unit 3 reactor automatically scrammed due to a Reactor Protection System (RPS) signal generated from Turbine Control Valve Emergency Trip System pressure low. The reactor had been operating near 73 percent power for an emergent issue for Turbine Control Valve (TCV) No. 3. With TCV No. 3 out of service and closed, the unit was operating with RPS in a half scram condition. A subsequent failure of the TCV No. 2 sensing line resulted in RPS coincidence logic being met for TCV fast closure SCRAM. The investigation of the TCV No. 2 sensing line failure continues.
"All control rods fully inserted into the core. Main Steam Isolation Valves remained open with Main Turbine Bypass Valves controlling reactor pressure. Reactor Feedwater pumps remained in service to control reactor water level.
"Primary Containment Isolation Signals Groups 2, 3, 6, and 8 containment isolation and initiation signals were received. Upon receipt of these signals all required components actuated as required. Neither High Pressure Coolant Injection nor Reactor Core Isolation Cooling initiation signals were received.
"This event is reportable within 4 hours per 10 CFR 50.72(b)(2)(iv)(B) ’any event or condition that results in actuation of the Reactor Protection System (RPS) when the reactor is critical except when the actuation results from and is part of a preplanned sequence during testing or reactor operation.’ It is also reportable within 8 hours per 10 CFR 50.72(b)(3)(iv)(A) and requires an LER within 60 days per 10 CFR 50.73(a)(2)(iv)(A).
"The NRC Resident inspector has been notified."
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2018/20180111en.html
La boutique
Informez vous