Electricity generation worldwide is based on an energy mix in which water power and nuclear power with shares of 18 % each represent economic mainstays free from CO2 emissions and, consequentl, without negative impacts of the climate. The use of water power as a source of renewable energy is unlimited in time. Rut what about the use of nuclear power? According to recent estimates by the London Uranium Institute, global uranium reserves amount to 3,4 million t (at extraction costs of up to $ 80/kg of U). This would allow a park of LWR plants of 400 G We, with direct disposal as the back end of the fuel cycle, to be fueled for fifty ol sixty years. A closed fuel cycle with Mox recycling would extend the period to approx, one hundred years; if breeder recetors were integrated into the fuel cycle, it would grow sustainably to many hundreds of years, with the accompanying effect of preserving fossil resources for alternative rues. The new development of safety concepts for future reactors (EPR and BWR-1000) satisfying the German 1994 omnibus law is going to take the current safety philosophy (residual risk) into a new, vastly improved, quality of safety. Re search into plutonium burning and the transmutation of longlived actinides and fission products will show to what extent, and subject to which economic penalties, the long term radiotoxicity indices associated with final storage can be reduced to the level of the indices of natural uranium ores.