Preliminary analysis of polonium-210 contamination for China LEAd-based Research Reactor

Highlights: • Evaluating the migration of ²¹⁰Po outside primary loop during normal operation. • Activation calculations have been performed using the MCNP and FISPACT-2007 codes. • The Raoult's Law was used to characterize the evaporation model of ²¹⁰Po. • The level of ²¹⁰Po in the reactor building of China LEAd-based Research Reactor could not be harmful to workers. - Abstract: An important issue should be considered for liquid lead–bismuth eutectic (LBE) cooled reactors, which is the accumulation of radioactive ²¹⁰Po generated by neutron-irradiated LBE. It could cause problems during maintenance or refueling operations. Considering the safety of China LEAd-based Research Reactor (CLEAR-I), the activity of ²¹⁰Po in LBE coolant was calculated by VisualBUS system developed by FDS Team. The evaporation process from LBE to cover gas and migration to containing room and reactor building during normal operations were evaluated in this present work. According to preliminary analysis, there is little ²¹⁰Po contamination diffusing into the reactor building and its level in gaseous effluent was within the limits of NRC Regulation (10 CFR). It could not lead to problems during normal operations.