None of those energy source is zero-ish. They all require upfront releases of CO2 to create, and end of life release to recycle.
Nuclear for base load and gas for peak/flexible demand is the most climate friendly solution available.
Nuclear for base load and gas for peak/flexible demand is the most climate friendly solution available.
All of them require that; but not all of them require it during the production. Some, like natural gas, do.