Thanks - didn't know about that one, and I'm grateful for the information .... It's been worrying me more and more that idiots (i.e. politicians) keep commissioning more and more nuclear power generation facilities without having any idea (and without even wanting to know) how we're going to clean up the aftermath. It's good to know that somebody has made at least one serious attempt to try it. Although ...
Still has the "what do we do with nuclear waste?" problem, but it was decommissioned anyway.
... as you noted, encasing the reactor vessel in concrete foam and burying it under 45 feet of gravel doesn't really cut it.
If you haven't seen it, there's a really instructive documentary ("Into Eternity"), made in 2010, about a nuclear waste storage repository ("Onkalo") being constructed deep underground in Finland, that is tackling - among other things - the extreme difficulty of figuring out how to construct signage ("Stay Away - Extreme Danger To Health") at the entrance to the facility, that will still be adequately durable, legible and understandable to descendant humans 100,000 years from now.
As the narrator says, "Onkalo must last 100,000 years. Nothing built by man has lasted one tenth of that time."
Another instructive documentary covers the herculean efforts made by the Russians/Ukrainians at Chernobyl to avoid a worse disaster than we already had.
It's a horrific story. They used soldiers to go up on the roof of the reactor building, each of whom could only risk being there for 45 seconds before getting their full dose for the year - enough time to chuck 2 shovelfulls of debris over the side, and then run away fast. In the end, they had to mobilise 500,000 (!) workers of all kinds to get the emergency cleanup done - and as we all know, even then it wasn't done very well, so much so that the EU is having to do it all over again.
I don't even want to think about how Fukushima's gonna go - it seems to be a worse mess than Chernobyl (albeit at a somewhat better designed & built power station). One fact that has stayed with me was how, at the time the tsunami took out the power, the on-site engineers had to go get their car batteries out of their own cars, bring them in, and wire them up in series so as to power up the control room instrumentation to find out what was going on in the reactors. We all owe those guys a beer.
It seems to me (somebody else coined this, not me) that our technological capabilities have advanced faster than we have evolved the ability to safely manage them, and we should just take a step back and do some very careful thinking. We can afford to reduce our lifestyles, wait a while, and revisit The Plan repeatedly until its perfect - we only have the one planet. It's the greedy short-termism involved in the rush to have it all that disgusts me.
Personally I imagine the way forward will involve giant solar panels in orbit collecting the Sun's bounteous energy and somehow transmitting it down to the surface. I have no idea whether that's just science fiction :-) .... it does of course require everyone to stop fighting wars, and divert all the money back into a proper space programme.