5.2. “The safety case has to include the output of the safety assessment ([see the following]), together with additional information, including supporting evidence and reasoning on the robustness and reliability of the facility, its design, the logic of the design, and the quality of safety assessment and underlying assumptions. The safety case may also include more general arguments relating to the disposal of radioactive waste and information to put the results of safety assessment into perspective” [1]. Such arguments include comparisons of predicted radionuclide releases with exposures to natural background concentrations and radiation levels, as well as comparisons with natural analogues. Remaining uncertainties and “Any unresolved issues at any step in the development or in the operation or closure of the facility have to be acknowledged in the safety case” [1]. Further work to address unresolved issues is likely to be necessary if they impact on the evaluation of safety.