12 juin 2014
Lors de la surveillance programmée de débit d’eau réfrigérée sur les deux réacteurs, un interrupteur a été mal positionné et a désactivé les voies redondantes de refroidissement de secours. Aucun système de secours n’était disponible sur les deux réacteurs du site.
Type BWR Mark 2 - Puissance : 3952 MWTh : Première divergence n° 1 : 09/1982 ; n° 2 : 05/1984
Available in english only.
Event Number : 50198
Facility : SUSQUEHANNA - State : PA - Unit : [1] [2] - RX Type : [1] GE-4,[2] GE-4
Event Date : 06/12/2014 - Event Time : 14:44
Emergency Class : NON EMERGENCY 10 CFR Section : 50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
Initial PWR : 100 % - Current PWR : 100 %
Event Text
SYSTEM RESTORATION ERROR CAUSES BOTH TRAINS OF CONTROL STRUCTURE CHILLED WATER SYSTEM TO BE INOPERABLE
"On 6/12/2014, [multiple Limiting Condition of Operations] LCOs were entered on SSES Units 1 and 2 for an inoperable Division 2 train of Control Structure Chilled Water starting at 1344 EDT for the planned performance of a flow surveillance. During restoration steps at 1444 EDT on 6/12/2014, a Division 1 Control Structure Chilled Water control switch was mistakenly manipulated which caused the redundant operable train to be declared inoperable. During this time both divisions of Control Structure Chillers were inoperable and were not available to perform the required safety function. This is a condition that, at the time of discovery, could have prevented fulfillment of a Safety Function and is reportable under [10 CFR] 50.72(b)(3)(v)(D) as an 8 hour notification.
"The loss of safety function is based on 1) the SSC is inoperable in a required mode of operation, 2) the inoperability is due to personnel error, and 3) there was no redundant equipment in the same system that was operable.
"The Division 1 train of Control Structure Chilled Water was restored to operable status at 1446 EDT on 6/12/2014."
The licensee notified the NRC Resident Inspector.
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2014/20140613en.html#en50198