21 février 2015
Lors de la survenue du problème, le cœur du réacteur était critique à 100 % de sa puissance. Selon la NRC, l’injection auxiliaire d’eau s’est enclenchée comme prévu et les barres de contrôle se sont correctement insérées.
Type : PWR - Puissance : 3 459 MWth - Première divergence : 01/1996
Available in english only.
Event Number : 50839
Facility : WATTS BAR - State : TN -
Unit : [1] - RX Type : [1] W-4-LP
Event Date : 02/21/2015 - Event Time : 10:32
Emergency Class : NON EMERGENCY 10 CFR Section : 50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
PWR Initial : 100 % Current PWR : 0 %
Event Text
MANUAL REACTOR TRIP INSERTED DUE TO RAPID LOSS OF MAIN CONDENSER VACUUM
"On February 21, 2015 at 10:32 EST, Watts Bar Nuclear Plant Unit 1 reactor was manually tripped due to rapidly dropping main condenser vacuum. Concurrent with the reactor trip the Auxiliary Feedwater system actuated as designed.
"All Control and Shutdown rods fully inserted. All safety systems responded as designed. The unit is currently stable in Mode 3, with decay heat removal via Auxiliary Feedwater and S/G PORVs. Main Steam Isolation Valves are closed. The Station is in a normal shutdown electrical alignment.
"The cause is currently under investigation.
"This is being reported under 10CFR 50.72(b)(3)(iv)(A) and 10CFR 50.72 (b)(2)(iv)(B).
"The NRC Senior Resident has been notified."
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2015/20150223en.html