5 octobre 2015
Des vulnérabilités ont été identifiées dans deux zones spécifiques "incendie" et des mesures compensatoires ont été prises. Une préoccupation concerne la peu probable (Sic) nécessité d’évacuation des forces d’incendie de la salle de contrôle. D’autre part, des vannes motorisées pourraient ne plus être commandées depuis la salle de contrôle suite à des problèmes dans le câblage de commande. Des modifications ingénierie sont en cours de développement pour résoudre ces problèmes. Cette déclaration obligatoire est produite suite à la dégradation importante de la sécurité de l’usine.
Type : Fukushima I (BWR Mark I) - Puissance : 2 028 MWth - Première divergence : 06/1972
Available in english only.
Event Number : 51456
Facility : PILGRIM - State : MA
Unit : [1] - RX Type : [1] GE-3
Event Date : 10/05/2015 - Event Time : 17:25
Last Update Date : 10/05/2015 Emergency Class : NON EMERGENCY 10 CFR Section : 50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
Initial PWR : 100 % Current PWR : 100 %
Event Text
SAFE SHUTDOWN ANALYSIS FOR FIRE EVENT - OPEN ITEM WITH POTENTIAL TO IMPACT CAPABILITY TO OPERATE MOTOR OPERATED VALVES
"At 1725 [EDT] on Monday, October 5, 2015, while updating the site fire safe shutdown analysis report, Pilgrim Nuclear Power Station (PNPS) identified vulnerabilities in two (2) specific fire areas that required a compensatory fire watch. The compensatory fire watches have already been established.
"The specific concern involves the unlikely scenario that fire forces evacuation of the control room. In addition, it is postulated that motor operated valves cannot be operated from their alternate control location due to spurious operation caused by hot shorts in control wiring. The specific failure mode is described in NRC Information Notice (IN) 92-18.
"Engineering modifications are under development and scheduled for implementation to address this specific IN 92-18 concern.
"Based on the above, the condition is reportable to the NRC as an unanalyzed condition that significantly degrades plant safety. As such the condition is reportable under 50.72(b)(3)(ii)(B), and requires an 8 hour notification.
"The licensee has notified the NRC Resident Inspector."
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2015/20151006en.html#en51456