26 octobre 2017
La perte de charge est due à l’activation du système de protection du cœur (RPS) dont l’origine est en cours de recherche. Suite à la tombée du réacteur il y a eu l’activation du système d’alimentation auxiliaure en eau suite à un niveau bas sur le générateur de vapeur n°2A. Lors de cette activation, une des deux vannes d’isolement du générateur ne s’est pas actionné mais le niveau a été rétabli dans ce générateur de vapeur et le générateur n°2B est alimenté par le circuit d’eau prinicipal. La pression est maintenue à 150 Bars et la température à 278 °C.
- Type : PWR - Puissance : 2 700 MWth - Première divergence : 6 / 1983 -
Available in english only
Event Number : 53036 - Facility : SAINT LUCIE
State : FL - Unit : [2] - RX Type : [2] CE
Event Date : 10/26/2017 Event Time : 02:12 [EDT]
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 Person (Organization) : SHANE SANDAL (R2DO)
Initial PWR : 100 % Current PWR : 0 %
Event Text
AUTOMATIC REACTOR TRIP FOLLOWING A LOSS OF LOAD
"On October 26, 2017 at 0212 EDT St. Lucie Unit 2 experienced a reactor trip due to a loss of load event resulting in an RPS [Reactor Protection System] actuation. The cause of the loss of load is currently under investigation. Following the reactor trip, an Auxiliary Feedwater Actuation Signal occurred due to low level in the 2A Steam Generator. One of the two Main Feed Isolation Valves to the 2A Steam Generator did not close on the Auxiliary Feedwater Actuation Signal. 2A Steam Generator level was restored by Auxiliary Feedwater. The 2B Steam Generator level is being maintained by Main Feedwater. All CEAs [Control Element Assemblies] fully inserted into the core. Decay heat removal is being accomplished through forced circulation with stable conditions from Auxiliary Feedwater/Main Feedwater and Steam Bypass Control System. Currently maintaining pressurizer pressure at 2250 psia and Reactor Coolant System temperature at 532 degrees F.
"St. Lucie Unit 1 was unaffected and remains in Mode 1 at 100 percent power.
"This report is submitted in accordance with 10 CFR 50.72(b)(2)(iv)(B) for the reactor trip and 10 CFR 50.72(b)(3)(iv)(A) for the Specified System Actuation."
The licensee notified the NRC Resident Inspector.
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2017/20171027en.html
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