Fig. 4-4 Production process of raw material Production process of raw material

Fig. 4-5 Adsorbing cartridge Cylindrical cartridges (12 cm in diameter, 8 cm in height) set into an adsorbing tube. The used cartridge is reduced to nearly 1/3 its original weight by incineration.

Many research institutes have a central facility for treatment of liquid waste containing beta and gamma emitters, but not for treating alpha emitters. At research institutes such as JAERI that do handle Pu and other alpha emitters, it is often necessary to eliminate alpha emitters from liquid waste prior to treatment. A material capable of adsorbing only Pu from liquid waste has been developed during routine work at JAERI. Charcoal is not only manageable after application, but also stable. Considering these features, activated charcoal in fiber form was applied to the decontamination of liquid waste carrying with Pu. In a rigorous study, JAERI staff found that carbon fiber selectively and effectively adsorbs Pu. Performance of the carbon fiber can be improved by adjusting the pore size, which affects its hydrophilic characteristics. Functional carbon fibers were molded into the shape of a cylinder to retain convenient handling characteristics and burnability. The cylinders were tested on liquid waste carrying Pu, and data was obtained showing removal of 98% of Pu. Subsequent incineration of the carbon waste cartridge led to a highly reduced volume of secondary waste. The technique would be useful to many countries that have aging nuclear facilities, and for decontamination of reactor facilities following an accident. It is expected that this technique will be widely used in the treatment and conditioning of liquid waste containing Pu, as well as for Pu recovery.

Reference T. Mimori et al., Development of Pu Adsorption by Fibrous Actuated Carbon (FAC), Dekomisshoningu Giho, 14, 73 (1996).

Select a topic in left column