Preliminary Study of Long-life GFR 100 and 150 MWth

Abstract

The breeding capability of fast reactor allow the reactor to operate in a long life time, but with the risk of a large reactivity swing and high power peaking in the center of the core. Both of these factors can be reduced by adjusting the fuel with a right configuration. This is down in this study, where optimization is performed on 100 and 150 MWth reactors, with the aim to getting the reactor to operate for more than 20 years with Power Peaking factor (PPF) is less than 1.3 and reactivity swing less than 1%. Based on the optimization result, a maximum configuration of fuel in inner, mid, and outer core of reactor I and II is given by 6.6%, 11.6%, 12.4% and 6.6%, 9.8%, 14.0%. Neutronic analysis results of this design indicate that the reactor II can only operate for 29 years, while reactor I can operate for more than 30 years because it has a larger conversion ratio (CR). The PPF value of reactor II is greater than reactor I caused by fission rate in the center of the core of this reactor is larger as a result of the short buildup process. Reactivity swing of reactor I and II are 0.25% and 0.16%, where the maximum reactivity of reactor I is 1.02% and occur in BOL, and for reactor II, the maximum reactivity is 1.03% and occurred in the 18th year.