The labeling of nuclear power as "renewable" or "green" has been a source of litigious contention for several years now. The difficulty is that nuclear power releases significantly less carbon emissions than conventional energy sources, but it does, nevertheless, have a detrimental impact on the atmosphere's air, and therefore cannot be categorized with energies such as wind or solar power.
Furthermore, it is argued that nuclear power is not renewable—while it uses a very small amount of uranium in the fuel source, uranium is nevertheless a nonrenewable resource, and at some point will be exhausted. When it is, at present uranium cannot be artificially regenerated.
However, when used in breeder reactors, nuclear fission actually generates more isotopes than they require, forcing the American Petroleum Institute to acknowledge nuclear power in breeder reactors as green energy. If nuclear power were used exclusively in such facilities, then nuclear energy would be constantly replenishing uranium, as well as plutonium. Further, any renewable energy source—solar, oils, or any other fertile materials—are also nonrenewable up to a certain point; they just exist in such great abundance and unrestricted availability that they are considered renewable. Even the amount of wind power that can be harnessed from the flow of air is ultimately limited, it just does not occur to anyone yet as detrimental, because we currently take a negligible amount of the resource relative to how much exists around us. The same goes for uranium in the case of nuclear power.
Essentially, the question of categorizing nuclear power as a renewable energy is one of perspective: while not the ideal energy resource, it is also much cleaner than the most conventional fuel sources in use today. If the entire world could somehow switch from technologies fueled by oil and gas to pure nuclear energy, this would drastically reduce the carbon emissions that are currently eating away at the Earth's atmosphere. However, the determination of this seemingly trivial label of nuclear power as "green" or "renewable" makes a big impact on those working in the industry. Qualifying as such a resource would give nuclear energy researchers and developers access to government grants that could make a world of difference to the quality of their work, and the speed of their process of sophisticating nuclear energy for use. In short, the question is between principles and utility, and right now, we are in an ecological place that demands quick action and utilitarian thinking.