Fusion–fission hybrid system for nuclear waste transmutation (II): From the burn-up optimization to the tests of different data libraries

A possibility to use a fusion–fission molten salt (flibe) hybrid system to incinerate nuclear waste minor actinides (Np, Am, Cm) is considered. In this work an optimization procedure was developed in order to determine the fission-blanket composition corresponding to fast incineration rate of minor actinides.Performance parameters such as ksrc, burn-up, neutron fluxes and equilibrium conditions were obtained. Monteburns code system (MCNP+ORIGEN) was used for system modeling. Approximately 1.1 ton of minor actinides, originating from the spent nuclear fuel, could be incinerated annually with an output of 3 GWth fission power. Detailed burn-up calculations show that the equilibrium conditions of the fuel concentration in the flibe transmutation blanket could be achieved, if the originating tritium and fission products were removed at least in part and fresh actinides were added during the burn-up on line.The optimal transmutation blanket in equilibrium is dominated by minor actinides for which the cross sections may vary depending on the nuclear-data libraries used. Therefore, the system performance was tested comparing different sets of data libraries. A number of major differences among ENDF, JENDL and JEF data files were identified and quantified in terms of the averaged one-group cross sections. In this context, our study could be directly generalized for other transmutation systems with similar neutron-energy spectra.