Can we talk about the waste that’s cast off when the reactor has finished its use of it? I understand the material will remain radioactive for centuries. Nobody wants that in their backyard.
CO2 emissions are a globally-uncontainable problem that we don’t know how to solve.
Nuclear is strictly better on the scale of waste problems.
To answer your question more practically though, our nuclear waste would fit into a building the size of a football field. There's even a proposal to put it in some mine/cave in the western United States.