I've worked on building a couple of those nukes. I can tell you from first-hand experience that what's coming out of those cooling towers is just steam .................. plain old steam. Much of the public thinks it's radioactive pollution - It's NOT. Huge pumps pump the cooling water from a closed-loop system up to the top of the cooling towers and then it free-falls like a waterfall inside the towers to circular basins at the bottom. Falling in free air inside the towers releases much of the heat from the hot water in the cooling water systems.
Much as your vehicle radiator cools your engine without being part of the combustion process that runs your engine, so is the closed-loop cooling system in a nuclear power house. The water doesn't become radioactive. It's just hot water.
And also from having worked on building nukes, I can tell you that accidents such as Three Mile Island won't happen anymore. After that accident, all nuclear plants were retro-fitted with redundant control systems, where TMI only had one control system. So when it failed .............. they were S.O.L. to stop an accident. Since TMI, control systems are electrical, hydraulic, pneumatic, and manually operated. Ifg one method of control fails, there are 3 other ones. If all the automatic systems fail, the reaction can be stopped by manually putting the control rods in place to stop the nuclear reaction. I worked on the bowels of the reactor ............... so I know how they operate.
Nuclear energy is VERY clean compared to coal, gas, or oil-fired power houses. No CO2 or other greenhouse gasses emitted. The only "waste" is the spent fuel rods - and French engineers have come up with processes that can extract more good use from spent fuel rods to further reduce their radioactivity. Centuries worth of power-supplying spent fuel rods can be stored in ceramic cylinders underground. Those cylinders have been tested by ramming full-speed diesel locomotives into them without breakage.
The problem with nuclear power is the industry itself. It does a poor job of explaining the processes, visuals (cooling towers & steam), and all the safety systems put in place after TMI happened. Those upgrades and redundant control systems are known as "TMI upgrades / retrofits" .................... because they were put in place AFTER TMI. Public safety was the overriding factor in those upgrades. EVERY piece of material - down to the last nut & washer - is inspected, tested and approved by the NRC (Nuclear Regulatory Commission). EVERY weld, EVERY anchor hole drilled, EVERY support - ....................EVERYTHING is engineered & inspected. NOT ONE MOVE is made without engineering approval. Average material from a hardware store or Home Depot / Lowes / Menards is NOT EVER used in a nuclear plant. Specialty suppliers only!! Such stringent measures and safety precautions are NOT taught to the public, ( which they should be! ) so the public doesn't trust nuclear plants.