I have to ask you one question: * What do you think of the risk of making the entire surface of the planet completely uninhabitable to humans might be over a long period of time? So, let's apply a kind of bayesian filter to history, or rather, looking forward into the future. Economics, geopolitics, the universe and all other kinds of sources of entropy GUARANTEE that reactors degrade over time and need to be replaced. Not only that, there are layers of entropy involved here. The above point is just the first layer of entropy dealing just with the reactor at a mechanical level. The layers of entropy withing which the machine sits is a huuuuuuuuuuge problem, because at minimum humans will not only not want to spend the money to decomission old reactors for better designs, they will keep the current designs in production for 2x or more of their original life time design spec. I'm all for rectors, it's the only technology available to solve our demand side problems. My fear is that over a long enough period of time, you don't need many reactors to start glowing to make most of our earths surface uninhabitable. Look at the surface area around Chernobyl and Fukushima and you can start to imagine that if it is true that hypersonic missiles are now entering russian, chinese and american arsenals, it wouldn't take very many of these things to totally make japan, america and europe vritually uninhabitable if someone really had the inclination. No such thing can be said about coal or other more conventional sources of energy, although coal plants just spew their radiation and other pollution over a longer period of time rather than one nice explosion of the containment dome. How do you feel about this problem? How are you thinking through that set of possibilities? Just curious.