Update on the Design Concept of a Lifetime-Core Particle Bed 300 MW(e) Boiling Water Reactor (VKR-MT). Annex II

In this paper an updated concept of the VKR-MT vessel-type boiling water reactor with micro fuel elements is presented. The targets of the update development were as follows: - Optimization of core parameters for fuel cycle characteristics and core lifetime extension; - Increase of micro fuel elements reliability under operating conditions; - Optimization of reactor design for core lifetime prolongation without refuelling within 25-30 years; - Development of a refuelling (reload) technique based on a special refuelling (reload) tank without opening the reactor vessel lid during 25-30 years. The VKR-MT incorporates proliferation resistance features (difficult access to fuel during the whole long period of reactor operation) provided by the following engineering solutions: - Internal reservoir, intended for fresh micro fuel elements; - Internal repository, intended for spent micro fuel elements; - Transport equipment of micro fuel elements inside the reactor vessel without power reduction or opening vessel lid, intended for realization of gradual core refuelling (reload) in accordance with the process of uranium depletion; - Container and equipment for micro fuel elements reloading are brought to the site after reactor operation during 25-30 years without opening the vessel lid. The original VKR-MT reactor design concept, the fuel assembly and micro fuel elements design, and the design of the equipment for gradual core refuelling without power reduction and opening of the reactor vessel lid have been modified to realize in full the above mentioned features