Case Study on Unexpected Tritium Release Happened in a Ventilated Room of Fusion Reactor

At the Tritium Process Laboratory (TPL) in Japan Atomic Energy Research Institute (JAERI), the three-dimensional "TBEHAVIOR" code has been developed and improved to understand initial tritium behavior and tritium confinement performance in a ventilated room of a fusion reactor in case of tritium leak event. The purpose of this study was mainly focused to; 1) investigate the effect of atmospheric exchange time per hour on the tritium confinement performance in an actual scaled tritium handling room after off-normal tritium release; 2) investigate the effect of atmospheric exchange time per hour on the time necessary for detecting tritium release; 3) investigate the suitable location of exhaust ducts and alarm monitors. The simulated room used in the present analysis is approximately 3000 m³ of tritium handling room (12.00 m^W, 29.00 m^D and 8.50 m^H) with six supply ducts and six exhaust ducts. Atmospheric exchange time per hour is changed as a parameter from 0.67 to 3.33 times per hour.