Evaluation of radioactive nickel distribution coefficient by analyzing background stable nickel

Abstract

A simple method of evaluating the distribution coefficient (Kd) of radioactive Ni was examined. The method is based on the measurement of the solid-liquid concentration distribution ratio (fd) of background stable Ni. To verify the method, the Kd´s of both the radioactive Ni and stable Ni were simultaneously measured by using three different samples through batch sorption experiments in which radioactive Ni with a constant concentration and stable Ni with various concentrations coexisted. The fd of background stable Ni was then measured by extraction with 0.1 N CH3COONH4 and 0.1 N HCl solutions to compare fd with Kd. The results showed that the Kd´s of radioactive Ni agreed with those of stable Ni, and that the fd corresponded to the Kd when the liquid-phase concentration of stable Ni approached the background level. This indicates that the method of evaluating Kd by using fd is applicable to Ni within the experiment.