Nuclear generates waste, but it's several orders of magnitude less, so it's much easier to manage. For coal, absolutely, there is fly ash, but if your plan is

Nuclear generates waste, but it's several orders of magnitude less, so it's much easier to manage. For coal, absolutely, there is fly ash, but if your plan is to just dump the current global production of aluminum into ponds every year, you are going to have a problem. These materials need to be recycled, not dumped. E.g. for a normal 2 inch thick cell. You have a volume of 600 million cubic meters that needs to be disposed of annually, and it's growing each year by 3%. The problem here is that people don't realize the scale of the issue -- and I was quite generous in my estimates.