If they take ten years to build, start now. Nuclear plants offset 400 million tons of CO2 a year in the US alone. All the waste produced since the 1950's would fit just over 9 meters deep on a single football field. Yes there's mining, it's not great, guess what? Solar panels and wind turbines also require mining. The open pit sort, the sort with wastewater containing the ever-perfidious radioactive elements. All in all, for each ton of rare earth elements extracted, about 2,000 tons of toxic waste is produced, 1-1.4 tons of which are radioactive, usually thorium and uranium funnily enough. A point of interest on the waste, the tailing dam of the Bayan OBO mine in China, responsible for only half the world's rare earth elements, is around 70 million m3, the nuclear waste I previously mentioned comes in at 49,000 m3, or 0.07% of the volume of a single mine.
All this to say, let's build solar panels, wind turbines and nuclear reactors, because we're in the harm reduction phase, and nuclear reactors are a fantastic tool even if they have downsides, just like everything else.
Oh, apologies, I assumed you could read. Never mind.