18 avril 2019
Un fusible grillé est à l’origine de ce confinement qui est survenu lors du remplacement d’un relais sur la logique d’une conduite principale de vapeur.
Le système d’évacuation de la chaleur résiduelle a reçu un signal d’isolement qui n’a pas respecté suite à la mise en place des procédures par les opérateurs. Liste des systèmes qui se sont déclenchés suite à l’isolation partielle : nettoyage de l’eau du réacteur - gaz de confinement primaire - eau glacée - refroidissement de l’enceinte du réacteur - pulvérisation du cœur -
Type : BWR Mark 2- Puissance : 3 515 MWth - Première divergence : 8 / 1989
Available in english only
Event Number : 54083
Facility : LIMERICK - State : PA Unit : [2] - RX Type : [2] GE-4
Event Date : 04/18/2019 - Event Time : 02:49 [EDT]
Emergency Class : NON EMERGENCY 10 CFR Section : 50.73(a)(1) - INVALID SPECIF SYSTEM ACTUATION
Unit 2
Initial PWR : 0 % Current PWR : 0 %
Event Text INVALID ACTUATION OF A UNIT 2 CONTAINMENT ISOLATION LOGIC DUE TO A BLOWN FUSE
"This 60-Day telephone notification is being made per the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) to describe an invalid actuation of Limerick Generating Station Unit 2 containment isolation logic.
"On April 18, 2019, while performing a relay replacement on the Division 2/4 Main Steam Line logic, a partial containment isolation occurred due to a blown fuse.
"The following systems had components that actuated due to the partial isolation : Reactor Water Clean-Up System Primary Containment Instrument Gas System Drywell Chilled Water System Reactor Enclosure Cooling Water System Core Spray System
"The Residual Heat Removal System received an isolation signal ; however, the system remained in service because the isolation was defeated in accordance with plant procedures.
"This event resulted in partial Group 2A, 3, 7A, 8A, and 8B isolations. The systems successfully functioned per the plant design and plant configuration."
The licensee notified the NRC Resident Inspector.
https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2019/20190422en.html