About the future reactors and fuel cycles

21st century is giving through the political challenges also technical challenges, how to ensure safety and stability mainly in the situation with the limited energy and other sources. An overview of the situation and vision of the future development in nuclear technologies will be shortly described with the special view to consequences to the closed nuclear fuel cycle strategy. General conclusion is to try to evaluate (even if there are great uncertainties) technology prices and compare them with expected raw material (nuclear and classical) accessibility and their prices in the period of the next fifty years. Full nuclear technology development and its introduction into the industry needs at normal occasion at least several decades' consideration to be able to be a standard part of our life. New structures of nuclear energy will not only lead to new higher actinides composition, but will generate waste problem on the interstate level. We shall try to introduce it into the AER Working group 'f' - Spent fuel transmutations and reflect it into the contemporary technical R and D works. (author)