Phase characterization and thermal study of SrF2 and NdF3 doped fluoride salt containing 78 mol% LiF–20 mol% ThF4–2 mol% UF4

In this report we communicate the behavior of NdF3 and SrF2 doped in MSBR fluoride salt (78 mol% LiF–20 mol% ThF4 –2 mol% UF4) up to 750 °C as observed from DTA and XRD. The eutectic composition of the fuel salt exists as Li3ThF7 and LiF. Formation of phases on addition of SrF2 and NdF3 in the eutectic mixture resulted in marginal shift in the melting point and the system shifted to ternary phase field of Li3ThF7–LiF–NdF3/SrF2. Additionally, incorporation of SrF2 in fuel salt resulted in precipitation of compounds like SrThF6 and a phase in the quaternary Li–Sr–Th–F system.