DESIGN OF SPENT-FUEL CONCRETE PIT DRY STORAGE AND HANDLING SYSTEM

An advanced dry storage system design with highly improved storage efficiency of spent nuclear fuel has been developed. The new concept \" Concrete Pit Dry Storage System\" realizes a safe and economical solution to an increasing demand of storing spent fuel assemblies (SFAs) generated from commercial nuclear power reactors. The system is basically composed of a large mass concrete module which has densely arranged pit boreholes, sealed canisters containing spent fuel assemblies and a canister handling system. The system is characterized by the following advantages compared with the existing concrete module type storage systems: higher storage efficiency can be achieved by the storage module filled with concrete which also gives a high shielding performance, simple handling technology is used for transfer and installation of the canisters at the storage facility as well as the transport cask of the canisters, surface contamination of the canister is prevented, lower radiation around the storage area is provided to reduce radiation exposure during handling and storage, high structural integrity of the facility is maintained by the concrete module with a simple construction, the ventilation gallery introducing cooling air to the pit borehole has an enough draft height to improve cooling performance of the system, • a result of the design concept, the storage system can store higher burn-up SF As with a short cooling period.