Economical 14 CO separation is very important to provide the means of removal and fixation of the radio-acitve carbon (carbon-14) in atomic power industry. 13 C has been separated from 13 C/ 12 C CO or 13 C/ 12 C CH 4 by cryogenic process conventionally. However, since the separation factor is not so large, the separation cost is very expensive and thus the industrial application of 13 C is very limited. Meanwhile, there is no report on the separation of 14 C from 14 C/ 12 C until now. The authors found that there was a great difference on the adsorption equilibrium coefficient between 14 CO and 12 CO when they are adsorbed on low SiO 2 /Al 2 O 3 ratio Na-X type zeolite (Na-X) at low temperatures.

Characterization of C-14 in PWR Radioactive Wastes has been researched and formation mechanisms of C-14 have been discussed. It was found from the research results that the chemical form of C-14 existed in primary coolant was organic and was low molecule compounds which are soluble in water． On the other hand, most of C-14 components existed in condensed liquid waste and existed on solid waste were insoluble in water and chemically stable. The insoluble C-14 component was considered to be produced by activation reaction between neutron and substances with nitrogen. Those were thought to be decomposition substances escaped from high molecular organic materials, such as ion exchange resin, diaphragm seal, etc.

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