Study on behavior of polonium produced from bismuth, 8; Basic experiment on polonium filter

Yamazawa, Yu*; Obara, Toru*; Sasa, Toshinobu   

The treatment of polonium, reaction product of bismuth, is one of the important issues for the nuclear systems using lead-bismuth alloy such as spallation target of transmutation experimental facility planned in J-PARC project. To collect polonium evaporated from liquid lead-bismuth, filtering experiment with stainless steel mesh was performed. Using vacuum vessel prepared by JAEA, small amount of lead-bismuth which was irradiated at JRR-4 reactor was heated and evaporated polonium can be collected by the stainless steel mesh located at the entrance of exhaust line. The transmission of polonium was observed as a function of lead-bismuth pot temperature, filter temperature, and filter configuration (mesh size and number). From the experimental results, high decontamination factor is obtained at low filter temperature condition.