Dissolution techniques with microwave heating devices for radiochemical analysis of ash and cement-solidified product samples

Haraga, Tomoko   ; Ishimori, Kenichiro ; Kato, Kenichi; Kameo, Yutaka ; Takahashi, Kuniaki 

In order to dissolve radioactive ash (fly ash and bottom ash) and cement-solidified product of radioactive liquid wastes, a dissolution method using microwave heating devices was developed. In present method, most metal elements in samples were extracted with HCl and HNO to sample solution and a precipitate with silica as the main ingredient was decomposed with HF and HNO. As a result, fluoride residue was sufficiently reduced and more than 99% of radionuclides were recovered to sample solution. The ash and cement-solidified product samples were successfully dissolved in a shorter time as compared with a conventional method by external heating.