Considerations in the safety assessment of sealed nuclear facilities

This report is a part of the International Atomic Energy Agency's radioactive waste management programme, whose objective is to provide assistance to Member States in developing guidance for identifying safe alternatives for isolating radioactive waste from man and his environment. This report attempts to integrate information from the previous reports on decommissioning of nuclear facilities, mitigation of accidents at such facilities, and performance assessment of disposal systems to provide useful advice and qualitative guidance to those responsible for performance and safety assessments of sealed nuclear facilities by giving an overview of possible approaches and techniques for such assessments. In this context, the establishment of requirements and rules governing the radiological safety of personnel, the general public, and the environment for sealing and post-sealing activities will enable the choice of the most appropriated approach and help to promote consistency in both decommissioning and waste management standards. The near-field effects discussed in this document include gas generation, interactions of the groundwater and the residual water with other components of the system, thermal, thermo-mechanical, radiation effects and chemical and geochemical reactions. 59 refs, figs and tabs