Disposal of vitrified high-activity waste in properly selected deep geological formations is the option that absorbs most of present R&D and appears as an acceptable solution from a technical point of view. As regards safety, disposal projects under development appear to satisfy present radiological protection criteria, even if much uncertainty exists in both models and input data. Other disposal concepts are, however, also being studied, with more limited effort. Their quantification in terms of costs and benefits is therefore rather uncertain at present. Among them the following are treated briefly: disposal in deep oceanic sediments, actinide separation and recycling, and extraterrestrial disposal. Taking into account the cost and development time required to bring these options to industrial operation, they should not be considered as alternatives to present projects of waste disposal, but rather as scientific research that may lead to industrial realization in a more mature nuclear age, in which the balance of costs, risks and benefits will be different. Long-term storage of either spent fuel or vitrified waste, although not an alternative strategy of disposal, is an option that has considerable effects on waste management and the fuel cycle in general. The three scenarios (disposal of vitrified waste in geological formations, extended storage, advanced disposal options) complement each other very well and none of them should be pursued at the sacrifice of the others.
Radioactive wastes and disposal options