Desorption of lithium 7 isotope from a degraded amberlite lithiated mixed-bed-resin

Abstract

Lithium 7 (⁷Li⁺) is an isotope, which is used in the nuclear industry as lithium hydroxide (⁷LiOH) for the chemical control (pH control) of the high purity reactor coolant water process in order to prevent corrosion in the Pressurised Water Reactor (PWR). Furthermore, the ⁷Li⁺ isotope is used in an ionic form in the nuclear grade cation ion-exchange resin. This resin is used to purify the nuclear reactor coolant water by reducing cationic corrosion by-products such as Cesium and Cobalt, which are generated from nuclear fission reactions. In view of the fact that an inorganic salt of the isotope is used as an alkali sing agent in the PWR, the use of lithiated resin prevents the removal of the ⁷Li⁺ isotope in the coolant water. As most users of the nuclear grade resin purchase their resin in bulk, it follows that the resin has to be evaluated in order to determine its usability. In certain cases, the resin may be considered unusable as a result of the degradation caused by unsuitable transportation and storage conditions. These, in turn, perpetuate the release of leachates, which may further contribute to corrosion in the PWR. This necessitated the undertaking of this study, which was to evaluate whether it is possible to recover the high value ⁷Li⁺ isotope from a degraded nuclear grade resin in such a way that the isotope may be used in the PWR.