21 janvier 2013
Arrêt automatique du réacteur suite à un niveau trop bas dans le générateur de vapeur. La vanne principale de vapeur était ouverte de 10 à 20 %, alors que l’ordre lui avait été donné pour une ouverture à 100 %. L’arrêt s’est effectué correctement.
Première divergence : mars 1985 - Puissance 1 168 - Type PWR -
Available in english only.
Event Number : 48687
Facility : WATERFORD - State : LA -
Unit : 3 - RX Type : [3] CE -
Event Date : 01/21/2013 - Event Time : 15:51 [CST]
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
Initial PWR 91% Current PWR 0% Hot Standby
Event Text
AUTOMATIC REACTOR TRIP DUE TO LOW STEAM GENERATOR LEVEL
"At 15:51 CST, Waterford 3 experienced an uncomplicated automatic reactor trip from 84.5% reactor power. The actuations of the Reactor Protection System (RPS) and the Emergency Feedwater Actuation System (EFAS) resulted from Steam Generator #1 Low Level, which is at a nominal 27.4% narrow range setpoint. Safety systems responded as expected.
"All three (3) Emergency Feedwater Pumps started and injected into Steam Generator #1. Auxiliary Feedwater pump has been started, feeding both Steam Generators (#1 and #2) at levels above the EFAS low level setpoint. All control rods inserted by the automatic RPS actuation. Electrical power is being supplied from normal off-site power and condenser vacuum is available for Steam Generator heat removal via the Steam Dump Bypass Control system. There are no safety systems out of service or inoperable, nor any safety system TS [Technical Specification] LCO [Limiting Condition for Operation] actions entered.
"The cause of the Steam Generator #1 Low Level condition, and associated Reactor Trip, is under investigation. This event occurred during the initial power escalation from refuel outage RF18, after attempting to place C Heater Drain Pump (HDP), the first of three, into service. After starting, C HDP tripped for a reason not yet verified. Subsequently, based on initial Control Room operator observations, the Steam Generator #1 Main Feedwater control valve position was observed to be at 10-20% open, but with an open position demand signal of 100%. Main Feedwater response to the reactor trip (Reactor Trip Override) was as expected."
The NRC Resident Inspector has been informed.
* * * UPDATE FROM WILLIAM HARDIN TO PETE SNYDER AT 1645 EST ON 3/7/13 * * *
The original reactor power level stated in the report should be 91% in lieu of 84.5%. This information has been changed in the event heading.
The licensee notified the NRC Resident Inspector. Notified R4DO (Werner).
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2013/20130308en.html
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