[en] The problem of disposal can be tackled in two ways: the waste can be diluted and dispersed so that the radiation to which any single individual would be subjected would be negligible, or it can be concentrated and permanently isolated from man and his immediate environment. A variety of methods for the discharge of radioactive waste into the ground were described at the Monaco conference. They range from letting liquid effluent run into pits or wells at appropriately chosen sites to the permanent storage of high activity material at great depth in geologically suitable strata. Another method discussed consists in the incorporation of high level fission products in glass which is either buried or stored in vaults. Waste disposal into rivers, harbours, outer continental shelves and the open sea as well as air disposal are also discussed. Many of the experts at the Monaco conference were of the view that most of the proposed, or actually applied, methods of waste disposal were compatible with safety requirements. Some experts, felt that certain of these methods might not be harmless. This applied to the possible hazards of disposal in the sea. There seemed to be general agreement, however, that much additional research was needed to devise more effective and economical methods of disposal and to gain a better knowledge of the effects of various types of disposal operations, particularly in view of the increasing amounts of waste material that will be produced as the nuclear energy industry expands