They did. https://en.m.wikipedia.org/wiki/Army_Nuclear_Power_Program https://en.m.wikipedia.org/wiki/Army_Nuclear_Power_Program One issue was that small-packag

They did. https://en.m.wikipedia.org/wiki/Army_Nuclear_Power_Program https://en.m.wikipedia.org/wiki/Army_Nuclear_Power_Program One issue was that small-package reactor designs of the 50s and 60s required highly enriched uranium... which doesn't seem like the best idea to leave lying around at (by definition) remote outposts.