[3F08-10] Core Neutronics Evaluation

[3F09] Effect of Na void propagation to void reactivity in Fast Reactors with Sodium Plenum

*Toshikazu Takeda¹, Koji Fujimura² (1. Research Institute of Nuclear Engineering ,University of Fukui, 2. Hitachi-GE Nuclear Energy,Ltd)

Keywords:Sodium Void Reactivity , Fast Reactor, Transient, Sodium Plenum

The void propagation dependence of the sodium void reactivity in fast reactors with sodium plenum was investigted. In the case of a UFOF, the sodium boiling in the sodium plenum occures near the core, and the sodium void reactivity in each region of the sodium plenum is storongly dependent to the void condition of the neighboring regions. Furthermore the void propagation dependence has to be included in transient analyses. Also the void propagation dependence was investigated when the core was voided.