A design study on the FBR metal fuel and core for commercial applications

A design methodology for the FBR metal fuel and core is del eloped. It cons ists of the fuel integrity prediction by a mechanistic analysis code, and t he core neutronic/thermal-hydraulic design in which the effect of the chara cteristic fuel behavior and fuel cycle technologies are properly considered . Based upon this methodology, a fuel and core design study for reactors of various output scale (150-1500 MWe) is conducted, and the feasibility of m etal fuel FBRs for the future commercial applications is reviewed. The resu lts show that the averaged burnup of as high as 90-150 MWd/t is achievable at the refueling interval of 1-2 years with 3-4 batches, regardless of the output scale. The maximum allowable cladding temperature is assumed to be 6 50 degrees C to avoid the liquid phase formation, which leads to the achiev able core outlet temperature of similar to 510 degrees C based on the curre nt hotspot factors estimation. It is found that high breeding ratio of grea ter than or equal to 1.2 can be enabled with relatively small blanket amoun t, owing to the very high internal conversion capability. Another advantage is that it is possible to significantly reduce the burnup reactivity loss at the slight expense of the burnup, in which case the core excess reactivi ty becomes as small as a few dollars.