Re: SafeStor
I believe the fuel is still on site (or rather next to the old site) at Zion.
This was a PWR. If the reactor has run its life without ever splitting a fuel element then there should be no contamination. All you're dealing with is neutron bombarded water, steel and concrete. The water can be diluted but then the half life of irradiated water from a PWR/BWR is pretty short anyway. Steel is also not too bad when it comes to irradiation.
The British gas cooled reactors contain many thousands of tons of graphite. The irradiated graphite is a much bigger problem, which is why the safestore periods are a lot longer.
Now if there has been a fuel melt in the core.... well now you have all sorts other things to clean up. I know Chappelcross suffered a fuel melt. And there is of course the pile at Sellafield that caught fire and has a whole load of melted fuel. It really is far better to just leave them well alone.
Here is an interesting doc about how they removed the graphite from Tokai:
https://www-pub.iaea.org/MTCD/publications/PDF/ngwm-cd/PDF-Files/paper%208%20(Fuji).pdf
A nice example of Japanese efficiency! There had been a promise made to return the site to green field within a certain number of years after the reactor shutdown. I could not see that level of efficiency and neatness being done in the UK. :(