Dampierre
 INES 2 |
Wrong positioning of fuel assemblies in the reactor vessel during refuelling operations |
On April 2nd, 2001, during Dampierre nuclear power plant unit 4 refuelling, a shift in the refuelling sequence has led to a wrong position for 113 fuel elements within the reactor vessel. This event had no consequences on EDF staff's safety. The ASN has requested EDF to proceed to a detailed analysis of the event causes together with its potential consequences.
INES 2 |
Error in operating rules leading to safety injection system unavailability |
When entering a shutdown state at the Dampierre plant, the Safety Injection System was made unavailable due to the application of an erroneous operating rule, which does not permit to fulfill the requirements of technical specifications. This rule had been written by the Tricastin Plant and was also used as it was (i.e. with the error) by Dampierre and Bugey plants.
This incident occurred several times on these three 900 MWe plants during the following years.
INES 2 |
Leakage on a piping connected to the primary circuit |
A leakage has been detected on a piping connected to the primary at Dampierre-1 on December 14, 1996. The leak rate increased and led the operator to shutdown the reactor in order to localize the leak before reaching the safety threshold of 230 l/hour on December 21, 1996.
The operator localized a non isolable primary water leak on a piping connecting the safety injection system to the plant primary system. The defected part of the pipe has been replaced during a one month outage.
INES 0 |
SLIGHT CONTAMINATION AT THE NUCLAR ELECTRICITY PRODUCTION CENTRE OF DAMPIERRE |
Unit 1 of Dampierre NPP is shutdown since the end of July for refuelling and various maintenance and control actions on the equipment. During maintenance, workers from EDF and outside companies have been slightly contaminated by radioactive iodine.
The maximum contamination observed was less than 1/30 of the maximum quantity authorized per year. To be on the safe side, the medical service of the plant is performing routine control tests on the people working inside the reactor building.
INES 2 |
UNAVAILABILITY OF THE IODINE FILTERING OF REACTOR CONTROL ROOM VENTILATION SYSTEM |
On 22 January the operator discovered that the iodine filtering circuit of the control room ventilation system was unavailable. This anomaly was due to the presence (since 23 December 1991) of plugs in both the lines of the circuit. This common mode failure of a system important for safety due in particular to inadequate procedure is classified at level 2.
Additional information by public release (MAGNUC):
