[en] The uncertainties associated with future international availability of energy minerals (fossil fuels and fissile materials) are identified and assessed. Inflation has muddied the relationship between uranium cost and grade of ore mined. Mining of very low grade uranium ores will have an environmental effect at least of the same magnitude as strip mining of coal, and the energy expenditure will be unjustifiable unless breeder reactors are in full commercial use. There is no substitute for uranium and its demand is tied solely to nuclear power generation. Therefore, a volatile market for uranium is predicted. (E.C.B.)