What is the coal waste problem and how is this comparable to the problem of nuclear waste? Nuclear waste is a technical problem, otherwise it would have been s

What is the coal waste problem and how is this comparable to the problem of nuclear waste? Nuclear waste is a technical problem, otherwise it would have been solved already. There are countries like France where they have 80% of their electricity generated by nuclear power and politics is absolutely pro-nuclear. Yet, they don't have a solution to the nuclear waste problem.