Analysis of experimental results of boiling event of reprocessed radioactive liquid waste

Yoshida, Kazuo 

An experimental study of boiling event using actual radioactive liquid waste has been conducted and reported by CEA for safety analysis of radioactive release accident of reprocessing plant. These experimental results obtained from open document have been analyzed to clarify the transfer mechanisms of radioactive material for applying these results to safety analysis of an actual plant. From analysis of these data, information have been obtained about concentration and activity of nitric acid of radioactive liquid waste in boiling condition on which ruthenium (Ru) transfer into gas phase depends. Transfer rate into gas phase of Ru has been estimated using these data. The result is over estimated by 200 times compared with experiment. It could be explained that NO coexisting with nitrous acid generated radio-chemically suppress the Ru(VIII) formation in the liquid waste.