Have you looked at what they are calling "Clean up"? I believe that in Britain they actually filled one reactor building (not just the reactor) with cement. I presume they removed the fuel first. And it's still considered a hazerdous area and entry is forbidden to most people. That's not anything I'd call "clean up". And, IIUC, the US hasn't figured out HOW to close down the Hanford reactors, and is threatening to pollute the Columbia river right down through Seattle. If we need to evacuate Seattle that will be a fair inconvenience. There have already been minor leaks.
I'm not really convinced we know HOW to clean up a reactor site. Even cleaning up after a gas station is a real problem.