  An advanced transmutation method is suggested that the long-lived Minor
Actinides (MAs) in the spent fuel can be efficiently transmuted in the
candidate Accident Tolerant Fuel (ATF). The transmutation of MAs is
investigated through the Monte Carlo simulations in two potential
fuel-claddings of ATF, U3Si2-FeCrAl and U3Si2-SiC. The critical loadings of MAs
are determined through the Linear Reactivity Model (LRM) in order to keep the
same reactivity as the current UO2-zircaloy system at the End of Cycle (EOC).
In all cases, excellent transmutation efficiencies are found for the most
important three MAs, 237Np, 241Am, and 243Am, of which the total transmutation
rates are around 60%, 90%, and 60%, respectively. If only the longest-lived
isotope 237Np is considered, one U3Si2-SiC assembly can transmute 237Np from
six normal assemblies. The loading of MAs has little influences on the
neutronic properties, such as the power distributions inside an assembly and
inside a fuel rod. The transmutation of MAs in the ATF assembly is shown to be
more efficient and safe comparing with the normal assembly, while other
important properties are kept, such as the cycle length and the power
distribution.
