The US army had portable reactors 60 years ago. They were deployed in Greenland, Alaska, Antarctica. https://web.archive.org/web/20220404082426/https://www.us

The US army had portable reactors 60 years ago. They were deployed in Greenland, Alaska, Antarctica. https://web.archive.org/web/20220404082426/https://www.usace.army.mil/About/History/Exhibits/Nuclear-Power-Program/Experimental/ https://web.archive.org/web/20220404082426/https://www.usace... At least some of them were produced at the Idaho Nuclear Engineering Laboratory, and one of them suffered an accident there due to operator error. That site was later renamed to Idaho National Laboratory when being "nuclear" became bad, and they're making these "new" ones, too.