Why do you need a transitional solution? Why not Manhattan-Project the heck out of a purely renewable replacement? Coal is, for a variety of reasons, a terrible stopgap. And nuclear buildout is too slow and expensive.

For the cost of building significant new nuclear, we could build the new storage mechanisms, and all the solar/wind needed. Faster.

Also here in the Netherlands something similar happened. A company with nuclear waste went bankrupt and it became a expensive problem.

That's a hard question. I certainly would not support replacing our nuclear plants with coal plants, I would prefer everyone stay with their current system and we go as fast as possible to replace them with something worth it : trying to replace a bad source with an other bad one, but a bit better, costs time, money and human resources.

But the article kind of make me raise an eyebrow when they say that for highly radioactive wastes, we just have to find deep burial sites that will know no geological activity for one million year. Certainly doesn't sound as easy as implied, especially if all earth starts using nuclear power as main energy source.

That being said, I remember reading a few months ago about a breakthrough in Germany in nuclear field, where no rare material (like plutonium) was needed, and wastes were greatly reduced. This could be a global way (and then, we may not even need renewable).