(An) experimental study on the leaching of borate waste and spent resin waste forms in a simulated sea water

Abstract

In general, leaching test is performed and mostly employed in the acceptance criteria for radioactive waste disposal and is considered very important because the rate of release of radionuclides from a waste form is one of the most important parameter in defining and evaluating the radionuclide source term in the disposal environment. NRC strongly recommended that the chosen leachant should be the most aggressive one. Therefore it is considered that the certain results of the leaching test should supply the information to evaluate the radionuclide source term and the basis to determine the most aggressive leachant in the leaching test. In this study, leaching test of borate waste and spent resin waste forms is performed in order to compare the leaching characteristics of the waste forms in a simulated sea-water with those in a distilled water. In addition, the sea-water with different quantities of NaCl is used as a leachant to evaluate the effect of NaCl concentration. The IAEA test method (standard leaching test) and apparent dissolution model are applied to analyze the leaching characteristics. The representative radionuclides are $Cs^{137},\; Co^{60}$ and $Sr^{90}$. According to this experimental results, the amounts of leached radionuclides in the sea-water is more than that in the distilled water for borate waste and resin waste forms.