24 mars 2020
Le 24 mars à 12 h 05 une fuite du circuit de refroidissement du cœur a été détectée. Son niveau dépassant les limites autorisées, le réacteur a 22 % de sa puissance, a été mis à l’arrêt mais en dehors des délais prévus. La déclaration du problème est officiellement réalisée suite à l’activation du système d’isolation du confinement primaire.
Type : Fukushima 1 (BWR Mark 1) - Puissance 2 923 MWth - Première divergence : n°1 : 10 / 1976 -
Available in english only
Event Number : 54603
Facility : BRUNSWICK - State : NC
Unit : [1] - RX Type : [1] GE-4,
Event Date : 03/24/2020 - Event Time : 12:05 [EDT]
Emergency Class : NON EMERGENCY 10 CFR Section : 50.72(b)(2)(i) - PLANT S/D REQD BY TS 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION Person (Organization) : Initial PWR : 22 % Current PWR : 0 %
Event Text
TECHNICAL SPECIFICATION-REQUIRED SHUTDOWN DUE TO UNIDENTIFIED LEAKAGE
"At 1205 Eastern Daylight Time (EDT) on March 24, 2020, a Technical Specification-required shutdown was initiated on Unit 1 due to indication of a leak in the drywell. Technical Specification Action 3.4.4.A, Unidentified Reactor Coolant System (RCS) leakage increase not within limit, requires RCS leakage to be reduced to within limits within 8 hours.
"It was expected that the leakage would not have been reduced to within limits within the required Technical Specification completion time ; therefore, this event is being reported in accordance with 10 CFR 50.72(b)(2)(i).
"Reactor water level reached low level 1 (LL1) following the reactor shutdown. The LL1 signal causes Group 2 (i.e., floor and equipment drain isolation valves), Group 6 (i.e., monitoring and sampling isolation valves), and Group 8 (i.e., shutdown cooling isolation valves) isolations. The LL1 isolations occurred as designed ; the Group 8 valves were closed at the time of the event. Due to the valid Primary Containment Isolation System (PCIS) actuation, this event is also being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A).
"Unit 2 is not affected by this event.
"There was no impact on the health and safety of the public or plant personnel.
"The NRC Resident Inspector has been notified."
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2020/20200325en.html