The in-vessel interim fuel storage

The two in-vessel fuel storage zones are where fuel assemblies are put in a waiting position before being loaded into the core, or where spent fuel assemblies are put in a cooling position, the time for the decay heat to decrease to sufficient levels.

Spent fuel still generates decay heat and must remain in the coolant for some time after the reactor is shut down. To avoid excessive delays between two operation cycles, it was chosen to store the spent fuel at the periphery of the reactor, in a dedicated zone and let it cool there. Because of the double fuel handling system chosen, there are two such zones, opposite each other at the periphery, each having a capacity of one half core. The fuel storage zones contain also one loading/unloading position each, where the fuel assemblies are handed over by the in-vessel to the ex-vessel fuel handling machines and vice-versa. A last hole is foreseen for the wet sipping machine. The latter allows to detect fuel assemblies containing failed fuel pins without unloading them from the reactor. The fuel storage zones contain also one loading/unloading position each, where the fuel assemblies are handed over by the in-vessel to the ex-vessel fuel handling machines and vice-versa. A last hole is foreseen for the wet sipping machine. The latter allows to detect fuel assemblies containing failed fuel pins without unloading them from the reactor.