The longest lived fission products are actually the LEAST radioactive. This inverse relationship exists because of the fundamental relationship between half-life and radioactivity. The longer a radioisotope's half-life, the lower its specific activity (radioactivity per unit mass)
You are like a firefighter who opposes using water (nuclear energy) to extinguish fires (reduce CO2 emissions) because people might drown.
But there is still plenty that needs to be stored for hundreds of millennium
There is no answer to that, and no amount of arguing by analogy, argumentum ad hominem nor wishful thinking can make that go away
It is a very good thing we do not need nuclear power