Development of treatment for low radioactive effluent in Tokai Reprocessing Plant, 1; Cement solidification process

Horiguchi, Kenichi ; Sugaya, Atsushi ; Tanaka, Kenji; Kobayashi, Kentaro; Sasaki, Tadashi*

In Nuclear Fuel Reprocessing Plant, it is necessary to dispose of a large amount of low level radioactive effluent containing nitrate as a major ingredient, safely and economically. Therefore, engineering developments concerning a cement based encapsulation process have been carried out in JAEA. From the view point of disposal cost decrease, a low level radioactive effluent is passed through the nuclide separation process before cementation to concentrate the radioactivity into the minimum volume for conditioning and disposal. Two kinds of effluents are generated as a result of the nuclide separation; A nitrate effluent of which the principal ingredient is nitrate with a comparatively low radiation level, and; A slurry effluent including several kinds of salts with a comparatively high radiation level. Non-radioactive stimulants were prepared for each of these waste streams, and used in encapsulation trials to investigate special slag cement, on a beaker scale and full scale(200-litres). Furthermore, JAEA has carried out hazardous material judgment for cement products and leaching test of the cement products which encapsulated actual effluent. I will report that result of there development trials.