Comparative Study of Basic Reactor Physics of the DFR Concept Using U-Pu and TRU Fuel Salts

The Dual Fluid Reactor (DFR) is a molten salt fast reactor developed by the IFK¹ based on the Gen-IV Molten-Salt Reactor (MSR) and the Liquid-Metal Cooled Reactor (SFR, LFR) concepts. The analysis reported focuses on the comparison between previous neutronic calculations with the default fuel salt of U-Pu mixture and new ones with a transuranium (TRU) salt fuel option under steady state conditions. They include criticality, neutron spectrum, spatial flux distribution and temperature coefficient values. Fuel based on molten TRU salts has already been considered for the MSFR and other molten salt reactor designs. Therefore, the DFR for the first time has a comparable baseline with other molten salt reactors, so that its performance with TRU salt fuel can be assessed.