Investigation of Polonium Removal Systems for Lead-Bismuth Cooled Fast Reactors Using a Tellurium Surrogate: Part II

The alkaline extraction method is being investigated as a method to remove polonium from a lead-bismuth cooled reactor. Tellurium was used as a surrogate for polonium for these experiments to quantify the migration from lead-bismuth to molten alkaline (NaOH). Experiments provided direct evidence that molten NaOH can effectively remove tellurium from lead-bismuth. A reduction of three to four orders of magnitude in the tellurium concentration in the metals was measured in the experiments. The experimental results also showed a higher than expected concentration of NaOH in the lead or lead-bismuth. A comparison between experiments operated at 427°C and 500°C respectively indicates that the higher operating temperature produces a higher removal rate of Te. Experiments where hot NaOH was injected into the crucible at the same temperature as the lead-bismuth eutectic (LBE) resulted in the rapid removal rate of Te and remained constant until the experiment was completed. This paper is a continuation of the results reported in the previous ICONE paper, (ICONE11-36614) providing an experimental update.