On 31. March 1994 towards 5:45 pm an explosion took place in rooms adjoining the former Rapsodie reactor.
The shock wave which followed the explosion caused a 300 sqm concrete slab to fall, destroying the circular adit located nearby. The dead body of a worker was discovered under the slab towards 10:30 p.m.. Four workers were rushed to the Manosque and Aix hospitals with multiple fractures.
This explosion was probably due to the hydrogen released following treatment of the slightly contaminated sodium with alcohol.
Rapsodie, a fast reactor which has been shut down for the past ten years, is currently being dismantled, and the sodium treatment operations were part of these dismantling operations.
This accident did not result in the contamination of wounded workers, personnel or the environment. Slight contamination (-10 Bq/sqcm) was observed in the immediate vicinity of the explosion crater. This contamination is related to the caesium present in the sodium.
In the vicinity of the explosion, the Rapsodie reactor pressure vessel itself was apparently not damaged by the shock wave. The ventilation system in the adjoining post-irradiation fuel assembly sectioning and inspection laboratory (LDAC) was interrupted for a period of three hours after windows and a door were smashed. Although this ventilation system performs dynamic containment for the laboratory, this event did not increase the level of contamination in this laboratory.
Owing to the important safety lessons to be learnt from this accident, it was graded level 2.
Event date: Thu, 31-03-1994