> No, it is using gas. I didn't find a precise quote, but it's very likely the gas is helium [1] You are right, but that doesn't make my other arguments invali

> No, it is using gas. I didn't find a precise quote, but it's very likely the gas is helium [1] You are right, but that doesn't make my other arguments invalid. All gasses are poor at transporting energy because they have very low density, specific heat and because you can't use state change. > Finally, the root cause of why nuclear power plants are so damn expensive is the lack of experience of their construction crews. Virtually every new nuclear power plant is a one-of-a-kind new construction. (...) This reactor is supposed to be followed by 18 more of the same design, on the same site. It doesn't have to be and the pebble-bed doesn't change anything in that regard. You can take any reactor design and replicate multiple times. Actually, a lot of reactors are made this way. Both Chernobyl and Fukushima actually had multiple reactors made from the same blueprint. The issue with pebble-bed reactor is that you must create a lot of them because of how much less dense they are in energy production. You produce much less energy from one so you must get so much better at producing a lot of them (in this case whooping 18 of them -- and that is only a start). All this will cause a lot of reactors and a lot of nuclear material. So even if the individual reactor design is safer, you get many more of them and this might offset any safety improvements. There is after all a lot of factors that we just do not control like terrorism.