APPLICABILITY OF INSOLUBLE TANNIN TO TRU AQUEOUS WASTE TREATMENT IN NUCEF: IMPROVEMENT OF BREAKTHROUGH CAPACITY BY TEMPERATURE CONTROL

摘要

The applicability of insoluble tannin to the treatment of aqueous waste contaminated with americium has been investigated. Using insoluble tannin to TRU aqueous waste treatment is considered highly effective for minimizing the radioactive waste because it consists of only carbon, hydrogen and oxygen and so its volume can be easily reduced by incineration. It was proved that insoluble tannin was applicable to waste treatment because of the high distribution coefficient and the adequate adsorption capacity of americium(III) in low nitric acid concentration (1). However, the adsorption kinetics was found to be slow. The slow adsorption kinetics of insoluble tannin is a problem to design practical waste treatment processes. In this report, improvement of breakthrough capacity by temperature control as a solution of the problem will be discussed. Breakthrough capacity was found to increase with raising temperature from results of column experiments using europium as a simulant of americium at a few temperatures. It becomes clear that insoluble tannin is applicable to Alpha Aqueous Waste Treatment Process in NUCEF.