INES-event
INES 2

Sticking of a control rod cluster during reactor scram

On 6 April 1996 a control rod jammed at the top of the core during a scram. The scram was due to an error in the realization of a periodic test of the rods. The incident had no impact on the fuel because the jamming of a control rod is anticipated by the design of the protection system.
Just after the incident, EDF performed control rod drop tests. No anomaly was detected.
EDF has not yet explained the origin of the incident. A similar event occurred at Paluel NPP in October 1995. In this case, the protection system was not required according to the physical state of the reactor.
Basic level 2, according to table II Box B1 of the user's manual

Location: BELLEVILLE-1
Event date: Sat, 06-04-1996
Nuclear event report
Legenda & explanation