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Etats-Unis : Salem : Fuite du liquide de refroidissement primaire




23 novembre 2015


L’urgence a été déclarée suite à la détection d’un taux de fuite supérieur à 38 litres par minute, le 23 novembre 2015, sur le réacteur n° 2. Pendant la recherche de la source de fuite du système de refroidissement d’urgence de la partie haute du cœur sur la tuyauterie de la soupape d’injection de sécurité, un moteur a ouvert la soupape. Les calculs réalisés par la salle de contrôle, à partir du niveau d’eau du pressuriseur, ont permis d’établir que le taux de fuite s’élevait à 61 litres par minute. La fuite s’est arrêtée à la fin de la fermeture de la vanne motorisée et de l’initialisation de la soupape de décharge. La fuite aurait duré une minute. L’urgence, qui a duré 4h12, a été levée quand le taux de fuite est passé en dessous de 38 l/mn. Le réacteur est en cours d’arrêt pour remplacer la soupape.

Type : PWR - Puissance : 3 459 MWth - Première divergence : 08/1980

Available in english only.


Event Number : 51563

Facility : SALEM Region : 1 State : NJ - Unit : [2] - RX Type : [2] W-4-LP

Event Date : 11/23/2015 - Event Time : 21:48

Emergency Class : UNUSUAL EVENT 10 CFR Section : 50.72(a) (1) (i) - EMERGENCY DECLARED 50.72(b)(3)(v)(D) - ACCIDENT MITIGATION

Initial PWR : 0% Current PWR : 0 %

Event Text

UNUSUAL EVENT DECLARED DUE TO REACTOR COOLANT SYSTEM LEAKAGE

"At 2148 EST on November 23, 2015, Salem Unit 2 declared an Unusual Event due to reactor coolant system leakage greater than 10 gallons per minute. While performing troubleshooting to determine the source of leakage from the Emergency Core Cooling System high head safety injection piping, a motor operated valve was opened and the high head piping relief valve lifted. Indications in the control room calculated the leak rate at 16 gallons per minute based on the change in Pressurizer level. The leak was terminated when the motor operated valve was closed and the relief valve reseated. The time [duration] of the leak was about one minute."

The licensee notified the NRC Resident Inspector.

Notified DHS SWO, FEMA Ops Center, and NICC Watch Officer. E-mailed FEMA NWC and Nuclear SSA.

* * * UPDATE AT 0105 EST ON 11/24/15 FROM BILLY MOWER TO JEFF HERRERA * * *

The licensee terminated the Unusual Event at 0100 EST on 11/24/15. The licensee will be cooling down and depressurizing to mode 5 in order to replace the affected valve.

The licensee will be notifying the NRC Resident Inspector as well as the New Jersey State police, Delaware State Police and local emergency dispatch.

Notified the R1DO (Dwyer), NRR EO (Morris), IRD MOC (Stapleton), DHS SWO, FEMA Ops enter, and NICC Watch Officer. E-mailed FEMA NWC and Nuclear SSA.

* * * UPDATE FROM JOHN OSBORNE TO JOHN SHOEMAKER AT 0341 EST ON 11/24/15 * * *

"This event is being reported in accordance with 10 CFR 50.72(b)(3)(v)(D). ’Any event of condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident,’ due to inoperability of both trains of the Emergency Core Cooling System high head safety injection systems.

"The unusual event was exited at 0100 [EST] on November 24th, 2015, when the Emergency Core Cooling System high head safety injection piping inlet valves were closed, ensuring isolation of the relief valve. The criteria for exit was leakage rate was below the 10 GPM rate. The plant is in mode 3 cooling down to mode 5.

"The licensee notified the states of New Jersey and Delaware, Lower Alloways Township, and the NRC Resident Inspector."

http://www.nrc.gov/reading-rm/doc-collections/event-status/event/2015/20151125en.html#en51563