Dry storage system for spent nuclear fuel DSS

The DSS is a Dry Storage System manufactured by INVAP for spent nuclear fuel. Spent fuel removed from the reactor of nuclear plants is usually stored in water pools where water acts as radiological shielding and as coolant. Pool water and pool building air require regular monitoring and maintenance. The DSS offers a more economical and safe alternative to store spent fuel which has had partial decay of its activity in the plant storage pool. The DSS alternative uses above ground concrete silos. With the DSS system spent fuel is loaded in steel baskets before fuel is removed from the storage pool of the power plant. Each basket holds several fuel bundles. Each basket is taken from the pool and dried in a shielded transfer cell. The basket loaded with dry fuel is then covered and seal welded. Each basket is transported inside a shielded container to its storage place in the concrete silo. The silo is a steel cylinder with capacity to store several baskets and surrounded by a thick reinforced concrete shielding. Baskets are housed inside the steel cylinder on top of each other. The silos are closed with a plug made of steel-lined reinforced concrete. When a silo is full the steel lining of the plug is seal welded to the steel cylinder. The system has been designed for a minimum of 50 years