Event Tree Analysis of Accidents During Transport of Radioactive Materials in Japan: The Assessment of A Tunnel Fire

Construction of a nuclear-cycle facility at Rokkasho-mura in Japan's Aomori Pref. is being planned. Its uranium enrichment plant is already operating. Motor carriers and ships are being used to transport SF, UF6, LLW, etc., in Japan and from overseas. As Japan is very mountainous, it is necessary to investigate the possibility of a tunnel fire and a fall from a bridge in evaluating the safety of transporting radioactive materials (RAM). Accident scenario probabilities and their environmental effects should be investigated, particularly since some routes pass through urban areas. To establish Probabilistic Safety Assessment (PSA) for transport of RAM in Japan, effective methods and assessment examples were investigated and discussed, and accident data were collected and evaluated.