Hitachi, Ltd.

Yoshiyuki Aoyama

Masami Matsuda

Fumio Kawamura

Makoto Kikuchi

Shin Tamata

Koichi Chino

Susumu Horiuchi

Hideo Yusa

Mamoru Mizumoto

Kazuhide Mori

A method of processing radioactive waste resin by pyrolyzing radioactive waste ion exchange resin generated in a nuclear plant such as a nuclear power station. First, the ion exchange resin is pyrolyzed at a low temperature, and the resulting decomposition gas is separated. Second, the ion exchange resin at a high temperature, and the resulting decomposition gas is separated. Finally, the residue of the ion exchange resin is hot-pressed into a molded article.

Method for processing radioactive waste resin

A method for processing spent radioactive ion exchange resin formed in a nuclear power plant by a two-step pyrolysis method. First, the spent resin is heated at 350.degree. C. to decompose functional groups selectively. Then the base polymer, formed as residue, is decomposed at a temperature above 350.degree. C., e.g. 600.degree. C. After the thermal decomposition, exhaust gases which require a special exhaust gas disposal means, such as NO.sub.x and SO.sub.x can be reduce to below 1/20.

Method of disposing radioactive ion exchange resin

In a method of processing radioactive spent ion exchange resin, the spent ion exchange resin is pyrolyzed in an inert atmosphere and harmful decomposition gas such as sulfur and nitrogen compounds generated during pyrolysis is separated. Next, the spent ion exchange resin is pyrolyzed in oxidizing atmosphere and harmless gases such as carbon dioxide and water vapor gases are separated. It is preferred that a transition metal as a catalyst be adsorbed through ion exchange into spent cation exchange resin, and an anionic atom group containing a transition metal as a catalyst be adsorbed through ion exchange into spent anion exchange, before both of the pyrolysis steps. The pyrolysis is carried out at two atmosphere stages, and the harmful and harmless gases are decomposed separately. The pyrolysis in both of pyrolysis steps is effected at a temperature in the range of from 240.degree. to 420.degree. C. The proportions of the sulfur and nitrogen compounds in spent ion exchange resin after pyrolysis, and also the processing volume of the spent ion exchange resin can be reduced. And scattering of radioactive substances can be prevented. By adding a catalyst to the spent ion exchange resin, pyrolysis is carried out at a low temperature.

Method and apparatus for processing spent ion exchange resin

Growing community of inventors

Kawasaki, Japan

Yoshiyuki Aoyama