Neutron Dose Assessment Using an Ebonite in Criticality Accident

Mikami, Satoshi   ; Yoshida, Tadayoshi ; Takada, Chie ; Tsujimura, Norio   

Feasibility study of a hard rubber named ebonite as an activation detector for fast neutron has been carried out. It contains about 30 wt% of sulphur and S(n,p)P reaction can be utilized for fast neutron dose assessment. Characteristics of ebonite, a feasibility of it as a neutron dosemeter are investigated. According to our examination results, the neutron dose assessment method using an ebonite can be applied to dose reconstruction in the fields such as fuel fabrication plant and reprocessing plant etc., and to personal working there too. For easy dose assessment, the conversion factors to neutron tissue kerma from spectra were tabulated as a function of thickness of shielding of steel and concrete. The disc-shaped ebonite is one of the most useful tools to evaluate the dose induced by fast neutrons in case of criticality accident. It has the advantage of simple handling, measurements and rapid dose assessment.