I believe there used to be a number of small reactors back in the day. But some poor design issues saw them canned. https://spectrum.ieee.org/tech-history/hero

I believe there used to be a number of small reactors back in the day. But some poor design issues saw them canned. https://spectrum.ieee.org/tech-history/heroic-failures/the-forgotten-history-of-small-nuclear-reactors https://spectrum.ieee.org/tech-history/heroic-failures/the-f... McMurdo ice camp in Antarctica briefly was run via contained nuclear reactor. I also wouldn't call it a Nimby issue. If a disaffected terrorist decided to blow up a small nuclear unit the issues would be considerable. Currently nuclear power plants are guarded like wartime POW camps. The army did also try to build portable nuclear power generators https://youtu.be/HPWDMHH4rY4 https://youtu.be/HPWDMHH4rY4