Investigation of ³H, ⁹⁹Tc, and ⁹⁰Sr transport in fractured rock and the effects of fracture-filling/coating material at LILW disposal facility

Batch adsorption, batch diffusion, and flow-through column experiments were conducted using groundwater and fractured rock collected in unsaturated zone to increase our understanding of sorption and transport behavior of radionuclides. Increasing K_d values were observed in the sequence ⁹⁰Sr, ⁹⁹Tc, and ³H regardless of the geological media tested. For all sorbing radionuclides, K_d values for the fracture-filling/coating material were observed to be higher than those for without fracture-filling/coating material regardless of the groundwater. These higher K_d values are the result of zeolite mineral in filling/coating material of fractured rock. The batch diffusion and flow-through column experiments were also conducted using the same fractured rock sample, and the results of diffusion and column experiments showed similar trend of radionuclide sorption and transport to sorption experiment. In this study, sorption K_d of radionuclide was determined and used to increase our understanding of radionuclide retardation through fracture-filling/coating materials.