Did one of the Japanese industrial giants not have a small scale nuclear reactor the size of a shipping container in development
IIRC Mitsubishi or Panasonic (I think it is), have a sub 2m cubed reactor intended to be setup and forget for 10 years that they have full designs (if not a protype) for.
The idea is you place them at main sub stations*, and whenever they need maintenance they are simply taken back to the factory, with a replacement dropped off (I think they are based on research for nuclear subs), one of the key design features was that in the event of a quake or similar they could scram automatically, and without any need for additional cooling - but at the expense of them being able to be reused without complete overhauls (one of the reasons conventional plants don't use the same system is that knocking out 1-2% of your total generating capacity long term is a very last resort and expensive thing to do, but knocking out something that can be replaced in days/weeks is acceptable).
Basically the idea is something close to a very heavy duty backup diesel generator, rather than a major infrastructure project.
One of the problems with it is that apparently it would require exactly the same planning/approval procedures for every installation of it as it would for something like Sizewell, despite being something like 1000th the size and quantity of radioactive materials.
It's still extremely heavy.
Back to the aircraft, from memory both the Americans and Russians had plans for them before ICBM's, an I think the Russians actually built one that they flew.
The problem is the radiation and cooling, from memory the Russians accepted a design that would have used forced air cooling over the reactor and venting straight out** (you would not want to be under it, or down wind of it!), whilst the American design was slightly less likely to give anyone under it two headed offspring, but still nasty and much heavier (so less payload).
Both designs would basically have only been able to have the crew work on them for a few months before they had reached lifetime exposure limits to radiation.
This is based entirely on memory, as I read something about them a couple of years back.
Slightly amusingly there were also designs for nuclear powered tanks (which isn't such a stupid idea, given that most tanks can only carry enough fuel for about a days operation, so are very vulnerable to supply line attacks), and I think they got as far as a prototype with them that basically bolted a reactor onto an existing chasis at the expense of virtually everything else before people cottoned on to the idea that a nuclear reactor on something that was going to get shot at a lot wasn't a great idea.
*And I suspect hospitals and government facilities that needed an independent power supply.
**There may have been one intermediate stage with the Russian design, and two with the American one, but I can't remember exactly, except that the Russians (from memory) accepted a much dirtier but easier to build design.
