Demonstrating the safety of near surface disposal facilities

The characteristics of the radioactive waste intended for near surface disposal are such that an emplacement near the biosphere can be permitted. This waste can be described as low level and short lived radioactive waste. Nevertheless, as the presence of small amounts of long lived emitters is unavoidable, the safety of near surface disposal requires assessment over the long term. Due to the proximity of near surface disposal facilities to the biosphere, there is a significant risk, in the long term, of human intrusion into the repository and this has to be taken into account in safety assessments. The life of a radioactive waste disposal facility consists of three phases: the operational phase, the institutional control phase and the long term safety phase. The paper reviews how the safety of near surface repositories is assessed in all three phases. (author)