Reduction of technology risk at NPP during radioactive waste management

Abstract

Abstract The authors developed a technology for disposing of liquid radioactive waste, which ensures the reduction of their exposure dose rate (MED) by concentrating radionuclides from liquid radioactive waste (LRW) inside the iron oxide matrix of radiation protective sorbents (ion exchangers). Due to the high density, iron oxide ion exchangers provide an effective radiation protective shield against photon radiation with an energy of up to 1.5 MeV. This will reduce the radiation background of “spent” sorbents. The possibility of obtaining a hydrolytically stable system of bonds with the surface of iron oxide minerals when they are modified with organic and inorganic modifiers is theoretically substantiated and experimentally confirmed. It was established that the hydroxyl groups of the surface of oxides are the main type of reaction centers along which their surface is modified. Modified iron oxide ion exchangers have high chemical and radiation resistance, thermal stability, mechanical strength and mass transfer rate. The conditioning technology of spent ion exchangers into cement matrices allows creating an engineering barrier providing effective radiation protection and safe isolation of radionuclides.