I'm not sure whether to laugh or cry that so many folks say Nuclear Energy is "zero emissions."
It seems they haven't heard what radiation means, it means stuff radiating outward, emitting outward, emissions. The root word of radiation is radiate, to emit something; and 'emit' is the root word of 'emissions.'
All they do is radiate toxic emissions, they emit: alpha particles, beta particles, gamma rays, and more.
Of course there are multiple answers, based on how one measures the toxic materials.* But it seems fairly obvious to me that nuclear power ranks right up there as creating some of the most toxic products and by-products known to humanity.
When you shut down a coal burning plant, or turn off your car, the emissions stop. You still have to deal with the lingering effects of the pollution that's been emitted, but no new emissions are being generated.
When you close down a nuclear power plant, the emissions DO NOT stop. The nuclear materials will not be emissions-free for thousands, maybe tens of thousands, of years. And since it seems they don't capture all of the heat generated by the process and turn it in to electricity, there is still heat being added (emitted) to the atmosphere (it appears lots of heat/steam goes out through the "cooling towers") when the nuclear plant is running.