Study on the cause of the fire and explosion incident at bituminization demonstration facility of PNC Tokai Works

Sato, Yoshihiko; Koyama, Tomozo; Miura, Akihiko ; not registered ; not registered; Shigetome, Yoshiaki

On march 11,1997, bituminization demonstration facility(BDF) in Tokai Reprocessing Plant (TRP) of power reactor and nuclear fuel development corporation (PNC) made fire and explosion incident. Investigation of the cause of the fire and explosion incident at BDF was carefully conducted. The main cause of the fire is clarified to have been physical heating inside the extruder that provided unusual high temperature of bituminized product at filling. Physical feating is considered to be derived from decrease of feed rate of liquid waste to the extruder. The causes of the explosion are accumulation offlammable gas generated from insufficiently extinguished bituminized product inside the filling room of which the ventilation system was shut doen. The gas was ignited by another ignition of the heated drum.