Experimental Study on the Removal of 14C in Radioactive Liquid Waste.

Abstract

Carbon-14 gives the largest collective dose commitment to the world population among the nuclides which are discharged from nuclear fuel cycle facilities, therefore this is a very important nuclide from the viewpoint of radiation protection. In neutron fields as in the vicinity of the cores of nuclear reactors, there are several nuclear reactions which regularly generate 14C in operation. Carbon-14 generated in water is contained in radioactive liquid waste on the occasion of maintenance of reactors etc. Because 14C emits only weak β-rays, it is difficult to detect 14C in liquid waste by ordinary monitoring methods. Therefore 14C has not been recognized as a major object for the treatment of radioactive liquid waste, and there has been little information on the treatment of 14C in water.In this study, we performed experiments on the treatment of 14C in liquid waste by conventional treatment methods for radioactive liquid waste such as ion exchange, chemical coagulation and precipitation, and evaporation. We examined the validity of these methods and the behavior of 14C liquid in waste. The knowledge obtained in this study is important to develop effective removal methods for 14C in liquid waste.