Dose assessment in the criticality accident at Tokai-mura

Endo, Akira   

The present paper reviews dose assessment in the criticality accident occurred in September, 1999, at JCO, Tokai-mura, Japan. In the accident, almost all doses were brought by neutrons and -rays emitted from the precipitation tank. Dose assessment was performed for three workers at the accident spot, JCO employees, emergency workers and members of the public by experts at JAERI, JNC and NIRS. The assessment was carried out using records of dosimeters, radiation monitoring data in and around the site, analysis of biological specimens, and computer simulation technique. Based on the results of dose assessment, It was concluded that and concluded that deterministic effects are not expected except for the three overexposed workers and that the probability of stochastic effects is very small and will be undetectable.