Conversion ratio analysis of CAMOLYP reactor design concept

A concept of a critical low power reactor called Critical Assembly for Mo-99 Isotope Production (CAMOLYP) was designed using a Th-232-U-233 fuel cycle. The dependence of U-235 for producing Mo-99 isotope is expected to be minimized by utilizing the breeding of Th-232 which is more abundant in nature. Unfortunately, CAMOLYP's conversion ratio is unknown yet. Therefore, a neutronic analysis and design modification of CAMOLYP are needed. The method used is to perform neutronic analysis to determine reactor criticality, conversion ratio, and neutron flux by using MCNPX 2.7. The results show that the proposed CAMOLYP's design has the highest conversion ratio of 0.106639. The conversion ratio of this reactor type is very small because of the sizeable parasitic neutron capture by H-1 nuclides in the water and the considerable neutron leakage at the top and bottom of the reactor core. Therefore, the CAMOLYP reactor can't entirely reduce the dependence on U-235.