Radioactive wastes. Safety of storage facilities

A radioactive waste storage facility is designed in a way that ensures the isolation of wastes with respect to the biosphere. This function comprises the damping of the gamma and neutron radiations from the wastes, and the confinement of the radionuclides content of the wastes. The safety approach is based on two time scales: the safety of the insulation system during the main phase of radioactive decay, and the assessment of the radiological risks following this phase. The safety of a surface storage facility is based on a three-barrier concept (container, storage structures, site). The confidence in the safety of the facility is based on the quality assurance of the barriers and on their surveillance and maintenance. The safety of a deep repository will be based on the site quality, on the design and construction of structures and on the quality of the safety demonstration. This article deals with the safety approach and principles of storage facilities: 1 - recall of the different types of storage facilities; 2 - different phases of the life of a storage facility and regulatory steps; 3 - safety and radiation protection goals (time scales, radiation protection goals); 4 - safety approach and principles of storage facilities: safety of the isolation system (confinement system, safety analysis, scenarios, radiological consequences, safety principles), assessment of the radiation risks after the main phase of decay; 5 - safety of surface storage facilities: safety analysis of the confinement system of the Aube plant (barriers, scenarios, modeling, efficiency), evaluation of radiological risks after the main phase of decay; experience feedback of the Manche plant; variants of surface storage facilities in France and abroad (very low activity wastes, mine wastes, short living wastes with low and average activity); 6 - safety of deep geological disposal facilities: legal framework of the French research; international context; safety analysis of the confinement system (multiple barriers, penalizing scenarios of evolution, passive and well-characterized barriers, as realistic as possible modeling, robustness); appreciation of radiological risks after the main phase of decay; 7 - conclusion. (J.S.)