2 avril 2015
La fuite de vapeur est survenue dans le bâtiment turbine près des vannes de contournement de la turbine. Après l’arrêt manuel d’urgence, le niveau d’eau a baissé en dessous de 51 cm entraînant un arrêt automatique des groupes II et III. La fuite de vapeur a été arrêtée par une action manuelle sur les vannes d’isolation principale de vapeur. La puissance du réacteur a été ramenée à 20 %, avant le lancement manuel de l’arrêt forcé. Le réacteur est en cours de refroidissement et dépressurisation en vue de réparer la fuite de vapeur.
Type : Fukushima I (BWR Mark I) - Puissance : 2 957 MWTh - Première divergence : 10/1971
Available in english only.
Event Number : 50949
Facility : QUAD CITIES - State : IL
Unit : [1] - RX Type : [1] GE-3
Event Date : 04/02/2015 - Event Time : 21:33
Emergency Class : NON EMERGENCY 10 CFR Section : 50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Initial PWR : 20 % Current PWR : 0%
Event Text
MANUAL REACTOR SCRAM DUE TO STEAM LEAK
"On April 2, 2015 at 2133 CDT, a manual scram was inserted on Unit 1 following discovery of a steam leak in the Turbine Building at the D-ring, near the Turbine Bypass valves. Following the reactor scram, reactor water level decreased to approximately -2 inches, which resulted in an automatic Group II and Group III isolation (expected response). The steam leak was isolated by manual closure of the Main Steam Isolation Valves. All systems responded properly to the event. Unit 1 remains in Mode 3, with cooldown in progress. Reactor water level is in the normal level band. The cause and details of the event are under investigation. Unit 2 was unaffected by the event and remains at 100 percent power."
Operators reduced reactor power to 20 percent before initiating a SCRAM. All rods fully inserted and the reactor is shutdown and stable. The electrical supply is in a normal shutdown lineup. The reactor is being supplied by normal feedwater, and decay heat is being controlled by use of the ADS valves. The licensee is currently cooling down and depressurizing the reactor in preparation for repair of the steam leak.
The licensee has notified the NRC Resident Inspector and the State of Illinois Resident Inspector.
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2015/20150406en.html#en50953