Criticality safety evaluation of the fresh fuel storage in NSRR; Under consideration of earthquake and tsunami occurrence

Motome, Yuiko ; Murao, Hiroyuki 

Nuclear Safety Research Reactor (NSRR) facility have been utilized for fuel irradiation experiments to study the behaviors of nuclear fuels under reactivity initiated accident conditions. Unirradiated test fuels used in fuel irradiation experiments and flesh driver fuel elements for reactor operation are stored in the fuel building of the facility. In response to the 2011 off the Pacific coast of Tohoku Earthquake, the impact of NSRR's nuclear fuel material usage facilities on external events beyond design requirements was evaluated. The subcriticality of the flesh fuel storage was confirmed in consideration of earthquake and tsunami as superimposed event.