Strange, Kirk Sorensen (the guy in the video) seems very sure that these are much safer then any other alternatives. They don't have to be pressurised and water

Strange, Kirk Sorensen (the guy in the video) seems very sure that these are much safer then any other alternatives. They don't have to be pressurised and water-cooled. Instead there's passive security with a frozen plug and a drain tank. Here's a longer documentary with lots of details (about 2 hours) http://www.youtube.com/watch?v=31HEijtqF5I http://www.youtube.com/watch?v=31HEijtqF5I