Modern nuclear power technology is safer, cleaner, and pollutes less than carbon based energy production. It can completely replace every coal or gas fired power plant RIGHT NOW. Wind and solar energy are nice to have as secondary sources of power, but they can't replace fossil fuels right now. Nuclear can.
Every environmentalist should be supporting the increased use of nuclear energy and the advancement of nuclear power technology. It is the one known solution we have for quickly lowering carbon emissions, and it is much safer than the fossil fuel power plants they will be replacing.