On a related note, I just got back from a road trip that took me through SE Idaho. I had forgotten that there was a big research lab out there (Nuclear Reactor Testing Station now Idaho National Labs). When driving I came across Arco, Idaho - the world's first atomic powered town.
Down the road you can stop an tour the EBR-1 reactor. This was the world's first breeder reactor that proved Enrico Fermi's theory that you can produce nuclear fuel. It is also the first reactor ever to produce electricity. It also was the world's first molten salt reactor.
This reactor actually was cooled with Sodium/Potassium salt (NaK).The problem with this is that both Sodium and Potassium are very dangerous elements on their own. They easily burn when exposed to air and water and are corrosive. They require very special systems for handling safely, and if there is an accident at the reactor they compound the problems.
This particular reactor did have a minor meltdown at one time, but nothing serious. However a reactor down the road, SL-1,
had a major meltdown that killed three people and released a significant amount of radiation into the area. Today it is all buried and covered with rubble to keep it from being dug in the far future. The three bodies removed from it were extremely hot and had to be buried in lead lined coffins.
What caused the explosion is unclear. But the three workers were working on the reactor over Christmas holidays doing maintenance. The central control rod was to be raised four inches as part of the procedure. Instead it was raised about 20 inches. Within about 4ms the water boiled into steam and blew the reactor vessel nine feet into the air and released a tremendous amount of radiation. One of the operators survived the initial blast and was removed at great risk to the first responders. However his dose was so high there was no way he could be saved. His body was initially putting out something like 4-500R/hr which is extremely dangerous.
This was in fact the first really bad meltdown on U.S. soil. Most people think it was Three Mile Island, but SL-1 was far worse.
There are some films on YouTube describing Phase I, II, and III of the incident and clean-up. They are very interesting if you want to see the aftermath:
https://www.youtube.com/watch?v=gIBQMkd96CA
The above is Phase I and II. The Phase III film is around too, but I can't find it right now.
Here are the rest of my photos of my tour of EBR-1.
https://plus.google.com/photos/10949930 ... q67L5JLvaA
If you find yourself in that part of Idaho, it is definitely worth checking out. I'm not a huge fan of museums, but this one and the National Cryptologic Museum are 100% nerd certified by me!