Molten salt fast reactor with U–Pu fuel cycle

•The solubility of UF4 and PuF3 in the eutectics LiF–NaF–KF is extremely high.•This experimental fact allows to create the fast reactor with the liquid U–Pu fuel.•MSFR based on LiF–NaF–KF can work in the equilibrium mode using as a fuel 238U only.•The subcritical MSFR-burner can work using as a fuel Am only.•MSFR-burner based on LiF–NaF–KF is capable to transmute 300 kg Am/year GWth.

In the last two years it was discovered that solubility of PuF3, UF4 and AmF3 in the eutectics LiF–NaF–KF are unexpectedly high (30 mol %, 45 mol % and 43 mol % correspondingly at 700 °C). This result opens the way for the development of the molten salt fast reactor with U–Pu nuclear fuel cycle (UPu-MSFR). The first calculations of the critical UPu-MSFR and subcritical MSR-burner of Am are presented.