On release of radionuclides from a near-surface radioactive waste repository to the environment

A closed near-surface radioactive waste repository is the source of various radionuclides causing the human exposure. Recent investigations confirm an effectiveness of the engineering barriers installed in 2006 to prevent the penetration of radionuclides to the environment. The tritium activity concentration in groundwater decreased from tens of kBq/l to below hundreds of Bq/l. The monitoring and groundwater level data suggest the leaching of tritium from previously contaminated layers of unsaturated zone by rising groundwater while ²¹⁰Pb may disperse as a decay product of ²²⁶Ra daughters.