Study of thermodynamic stability domain of MThF₆ (s) (M = Sr, Ba)

The fission product Sr and Ba, after generation in the reactor due to fission of ²³³U, might exist as SrF₂ and BaF₂, respectively in the molten fluoride medium of Molten Salt Reactor (MSR) using fluoride carrier salts. The high temperature interactions between SrF₂ and BaF₂ with the fertile fuel component, thorium fluoride (ThF₄) leads to form single ternary compound SrThF₆(s) and BaThF₆(s), respectively. The Gibbs energy of formation is the driving force for formation of any compound. Using the experimental thermodynamic data, to study the stability domain of SrThF₆(s) and BaThF₆(s), the chemical potential diagram of Sr-Th-F-O and Ba-Th-F-O system and ternary phase diagram of Sr-Th-F₂ and Ba-Th-F₂ system has been calculated. (author)