Dose assessment analysis on neutron source terms of 70 MeV proton and UC2 target reaction for RAON ISOL target system

Isotope Separator Online (ISOL) facility at the Institute for Basic Science (IBS) in South Korea has been designed for producing rare isotopes. The purpose of this work was to analyze the effect of the strategy on neutron source term to evaluate effective dose for ISOL target room. Several neutron source terms were generated by varying the dimensional distribution, the number of angular divisions, and the number of energy divisions. For the dimensional distribution of neutron source, a cylindrical distribution with same shape as the target was recommended in front wall and a cylinder and a point distribution were recommended in side wall. Also, more than 32 angle divisions which had within 1.5 % discrepancy both in the front and side wall was recommended for dividing angles. In a case of dividing energies, a discrepancy within 2 % was shown in the source terms divided into more than 100 divisions. However, in case that discrete energy distribution is used, the dose was highly overestimated as the number of energy divisions decreases.