CRBR nuclear, thermofluid, and advanced fuel conceptual design

The improvements effected in flow orificing and fuel conceptual design to achieve both the breeding ratio and fuel lifetime goals within the restrictions imposed upon the core and blanket are discussed. The effect of cladding temperature on fuel lifetime is illustrated for either inelastic strain limits or life fraction damage function limits. The temperature varies through life differently for different assemblies. The maximum cladding midwall temperature for the assembly illustrated is just over 13000F at the beginning of life, also calculated on a conservative basis. This results in a lifetime of 80 MWD/Kg. An initial temperature of closer to 12300F would be required to achieve a burnup capability of 150 MWD/Kg. It is thus apparent that either the temperatures of the cladding must be decreased, or improved cladding material is required in order to achieve 150 MWD/Kg. (auth)