Experimental study on boiling accident of high active liquid waste in reprocessing

Uchiyama, Gunzo ; Tashiro, Shinsuke ; Amano, Yuki ; Abe, Hitoshi ; Yamane, Yuichi  ; Yoshida, Kazuo ; Ishikawa, Jun 

The experimental study for source term data of radioactive materials has been conducted at a boiling accident of high active liquid waste (HALW) in reprocessing plants. In the study, three kinds of tests have been conducted including a cold small scale test, a cold engineering scale test and a hot small scale test. The following results were obtained: Ruthenium and Technetium were released into the gas phase in the form of both mist and gas under the boiling accident conditions of a simulated HALW. Non-volatile fission products (FPs) such as Nd and Cs were released into the gas phase in the form of mist. The release ratios of non-volatile FPs from a vessel of the simulated HALW were about 10. The release ratios of actinide nuclides such as Am were almost the same as those of non-volatile FPs.