Actinide burner fuel: Potential compositions based on the thermodynamic evaluation of MF–PuF3 (M=Li, Na, K, Rb, Cs) and LaF3–PuF3 systems

Thermodynamic evaluation of the (LiF+NaF+BeF2+PuF3) system: An actinide burner fuel

“…Since there are no experimental data known for this system, nor are the PuF 3 solubilities in the LiF-NaF solvent, the approach was such, that the PuF 3 solubilities in the LiF-NaF-BeF 2 matrix have been calculated based on the thermodynamic assessments as described above and the ternary parameters of the (LiF + NaF + PuF 3 ) system have been modified in order to obtain best possible agreement between the experiment and our calculation. As shown in figure 14 this modification did not have a big influence on the shape of the ternary phase diagram when compared to our previous study [16], however the two ternary eutectics are now found at T = 893 K and X(LiF) = 0.474, X(NaF) = 0.451, X(PuF 3 ) = 0.075 and T = 969 K and X(LiF) = 0.633, X(NaF) = 0.147, X(PuF 3 ) = 0.220, thus slightly off from the values published in table 5 in our previous work [16]. A saddle point has been found between the two eutectics at T = 972 K and X(LiF) = 0.621, X(NaF) = 0.189, X(PuF 3 ) = 0.190.…”

“…The excess Gibbs parameters for the (LiF + NaF), (LiF + PuF 3 ), and (NaF + PuF 3 ) systems have been optimized in previous studies [15,16], but for better orientation are presented below as well. The liquid solution of the (BeF 2 + PuF 3 …”

“…The (LiF + NaF + PuF 3 ) system has already been assessed in our previous work [16] in which the same ternary excess Gibbs parameters (equation (10) in [16]) were assumed to be the same as those obtained in case of the (LiF + NaF + LaF 3 ) system from [17]. In the present study these ternary parameters had to be neglected (set to zero) in order to reproduce the measured [6,7] solubility data of PuF 3 in the LiF-NaF-BeF 2 matrix.…”

Thermodynamic investigation of the (LiF+NaF+CaF2+LaF3) system

“…In the present case LaF 3 serves as a proxy compound to PuF 3 (AnF 3 ) as already demonstrated in earlier studies [2], since the direct use of PuF 3 would cause tremendous experimental restrictions. To develop a thermodynamic database first the binary sub-systems are assessed and the higher order systems are extrapolated according to the Toop [3] formalism.…”

The high-temperature heat capacity of the (Li,Na)F liquid solution

“…The fuel in the MSR is in the liquid state and since it circulates between the reactor core and the heat exchanger it serves at the same time as a primary coolant. In our previous studies [1][2][3][4] we have developed an extensive thermodynamic database of various fluoride systems and based on the properties derived from these assessments (melting temperature, vapour pressure, actinide solubility) several MSR fuel compositions have been proposed. Some of these fuel proposals contain LiF and NaF and therefore it is important to investigate other relevant properties of the (Li, Na)F liquid mixture.…”