Reduction of the Sodium Void Reactivity Effect by Using a ⁹⁹Tc Layer

Analyses were performed by using the U. S. advanced liquid metal reactor (ALMR) core design to determine the feasibility of using it as a ⁹⁹Tc burner while reducing the sodium void reactivity effect (SVRE). A layer of ⁹⁹Tc of variable thickness was inserted around the core midplane in rows 2 through 5, and all blanket assemblies were replaced with fuel assemblies. The results indicate that a core with a 34-cm-thick layer in rows 2 through 5 has the optimum characteristics of SVRE, ⁹⁹Tc destruction rate, and fuel enrichment.