Nuclear power plants use nuclear fission to produce electricity.
It is not a renewable energy. It needs a very specific fuel, very heavy and un stable atoms, like Uranium. This is a chemical element that is found in nature, but when it is extracted it does not regenerate itself. Spent fuel from nuclear power plants cannot be recycled, is highly reactive and difficult to manage. Therefore, there are management protocols that, if executed correctly, do not release pollutants.