14 août 2012
Le système de protection contre les surpressions a été trouvé inopérant suite à l’oubli d’une vanne en mauvaise position. Le réacteur est en arrêt à chaud.
Available in english only.
Facility : MONTICELLO - Region : MN - Unit : [1] Event Date : 08/14/2012 - Event Time : 20:45 Emergency Class : NON EMERGENCY 50.72(b)(3)(v)(C) - POT UNCNTRL RAD REL 50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
Event Text
SAFETY SYSTEM OVERPRESSURE PROTECTION FAILURE DUE TO CLOSED VALVES
"At 2045 [CDT] on 8/14/12, MNGP [Monticello Nuclear Generating Plant] Operations determined that valves RHR-82 and RHR-84 had been inappropriately closed as part of an isolation clearance order for work on shutdown cooling suction piping. These valves are required to be open to provide overpressure protection for RHR piping passing through primary containment penetration X-12. Upon discovery of the condition, Primary Containment was declared Inoperable and the Required Actions of Tech Spec 3.6.1.1 were entered. Following discovery, the isolation was restored and the valves opened. At 0001 [CDT] on 8/15/12, Primary Containment was declared Operable.
"This issue is being reported in accordance with 10CFR50.72(b)(3)(v)(C) and 10CFR50.72(b)(3)(v)(D) as a condition that at the time of discovery could have prevented the fulfillment of the safety functions of a system needed to control the release of radioactive material or to mitigate the consequences of an accident.
"The MNGP Senior NRC Resident Inspector has been notified of this issue."
The licensee will contact the Minnesota State Duty Officer.
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2012/20120816en.html
La boutique
Informez vous