The results of molecular-dynamics (MD) simulation are obtained for structural and thermodynamic properties of the molten system, Na 1- x Pb x ( x ≤ 0.1), at 698 K in the model of nearly free electronic gas (NFE approximation). The all numerical experiments are carried out by unified procedure: 1) equilibrating the MD cell 1 ps; 2) calculating partial radial distribution functions g a b ( r ) in 1, 5, and 10 ps; 3) data handling for calculating other characteristics. It follows from this that lead impurity in liquid sodium at concentration in the range of 1% - 10% is characterized by micro-heterogenetic structure in the form of cluster compounds with variable composition. Just therefore the sodium alloys, Na-M IV , with four-group elements of Periodic table have no eutectic in this range of additive concentrations. This eutectic is needed for modifying sodium coolant of the fast nuclear reactor. Therefore it is reasonable to find an alternative alloy of sodium with additive from adjacent groups which has a eutectic in this range of concentrations, for example, the eutectic, Na 0.929 Tl 0.071 , with melting point of 64°C. The modified sodium coolant by isotope, 205 Tl, can appear attractive for inhibiting the chemical activity of sodium just as the lead alloyed one.
KeywordsMolecular DynamicsLiquid SodiumLead and Thallium AdditivesMicro-Heterogeneous Alloys
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