The spent fuel will stay in the interim storage facility for several decades to cool down before final disposal.
When the spent fuel has sufficiently cooled down in the reactor hall’s water pools, the fuel assemblies will be transferred to the interim storage facility located in the power plant area. The water in the pools provides insulation against the radiation emitted by the spent fuel and further cools it down. The pools are deep enough to keep the stored fuel assemblies completely below ground level, with eight meters of water over them.
Potential transients and accidents as well as their effects have been taken into account in the planning of the interim storage. The storage structures have been designed so that a fire or potential equipment failure will not endanger the functionality of the storage or fuel cooling. The safety systems of the spent fuel interim storage facility are designed as redundant and are provided with back-ups, just like the systems of the actual nuclear power plant units.