Dry vault for spent fuel depository, basic outsets, operating results and safety of the 'CASCAD' plant

CEA built a facility in which spent fuel can be stored for a few decades (50 years), until favourable conditions prevail for its disposal. The main features of this project consist of a dry depository, which presents a low cost of operation, against a wet one which is more expensive due to the circulation and the continuous controls of the water. Fuel elements are cooled by a fully passive air circulation. This process allows a good efficiency without mechanical equipment and works all the better as the amount of heat to exhaust is great, in the limits of the design. This facility, known as 'CASCAD' (shortening for CASemate (=vault) CADarache) started up in 1990, and received its first canister of fuel on May 29th 1990. The basic design data of the facility, are reviewed the main techniques used for its construction are outlined the safety concepts are drawn and the first results determined by a looking-back over 4 years of working are presented. (K.A.). 1 tab