Fresh fuel storage consists of reinforced concrete facilities to store fresh fuel carried into the power plant until fuel loading after acceptance inspec­tion. Fuel is stored vertically in metal racks in a dry condition. Fresh fuel storage is constructed to prevent water flooding and is able to drain water which may have entered the storage.

The capacity for fresh fuel storage is designed considering that spent fuel storage pool accommodates fresh and reloading fuel assemblies in one refueling. The fresh fuel storage of ABWRs is designed to be able to accommodate 5 % of the fuel assemblies of the entire core.

Fresh fuel storage racks are designed to assure that the effective multi­plication factor is maintained at less than 0.95 even in a severe condition such as water flooding when the maximum amount of fresh fuel is being stored; this is done by holding a proper fuel assembly spacing to prevent criticality of storage fuel. In the analysis of subcriticality in fresh fuel storage, the infinite multiplication factor of fresh fuel in being loaded into the core is assumed to be 1.30 for a sufficient safety evaluation.