After actually looking at the numbers and the details regarding fusion technology, I've come to the conclusion that the advantages over fission are illusory. I

After actually looking at the numbers and the details regarding fusion technology, I've come to the conclusion that the advantages over fission are illusory. I think people believe that fusion is somehow "way more powerful", because they know that fusion bombs are way more powerful than mere atom bombs. Actually, in many of the most powerful fusion bombs, the vast majority of the energy is produced by fission, with fusion serving as only an intermediate step to release neutrons and create more fission. A step you don't need in a reactor, which can control the fission rate itself. My guess is that a lot of people who haven't looked at the numbers think that fusion is hundreds of times more powerful than fission. Well, let's look at those numbers: the fission of a uranium-235 atom produces 202.5 MeV. The fusion of D+T produces only 17.6 MeV. That's more energetic per unit mass of fuel, since D and T are just hydrogen isotopes, but if you do the math, it's only about 3.5 times more energetic even using this measure. And fuel mass is a tiny portion of the mass of the whole powerplant. To make it worse, hydrogen is far less dense than uranium (by a lot more than a factor than 3.5), so you actually end up with a lot more fuel volume and containment volume. There are other reactions than D+T, but none of them look as good as plain old fission. That's before we even get into the fact that for most fusion reactions, a lot of the energy goes into extremely dangerous neutrons. The talk about "getting the fuel from seawater" is also misleading. It's technically true, but the process is very expensive, and, if we are going to talk about seawater, uranium can also be extracted from it. Finally, the idea that the danger from proliferation would go away is also false - anything producing a neutron flux as strong as a fusion reactor can be used to produce isotopes suitable for a bomb. And even aneutronic fusion (which is technically even more difficult) can be made to produce neutrons with suitable additions to the fusion fuels. EDIT: P.S. I am not an expert. I do think I can understand numbers and technical arguments, and I would love to hear expert analysis. But one thing: for every technology which you assume will help fusion (such as wonder-containments for the neutrons), please analyze how fission reactors would benefit from it, as well. Then let's see if we can make fusion come out "better" than fission in some meaningful sense. EDIT: I can't resist adding that the talk of "harnessing the reaction that powers the Sun" is aimed at people who don't know the numbers, and is very annoying. The Sun is not a good model; it has a huge mass (duh), and a tiny surface-to-mass ratio, which is why the energy it produces makes it so bright. But pound-for-pound, the Sun produces a lot less energy than slightly warm chicken soup. Do the math yourself, and be surprised. We can not build a reactor that works like the Sun.