The prospect of a major warming of our climate requires switching to energy sources that do not increase the amount of CO₂ going into our atmosphere. This talk will begin with a brief overview of alternate energy sources to point out the unique role that can be played by nuclear energy. This will be followed by a review of the present generation of nuclear power reactors. The main focus of the talk will be on the new generation of sodium-cooled reactors, of which the proposed Galena reactor is one example. I will describe some of the technical advantages of this technology and will describe how this new generation will impact issues relating to sustainability of resources, nuclear waste, proliferation and nuclear terrorism. I will conclude with a brief mention of the high-temperature reactor, which can be used to deliver hydrogen with high efficiency.