Nuclear powered tanks...possible?

I was just wondering if its possible to make a nuclear power plant small enough to power a tank the sized of, say, the M1 Abrams. If you could do it, would it be a good idea? I’m looking from both a performance perspective as well as crew/environmental safety. I assume if you could do something like a pebble bed reactor (but small) that it would be fairly safe if it took battle damage…but is that true?

(this discussion evolved out of a bull session tonight lamenting the horrible amounts of fuel the M1 requires to opperate in the field and looking at possible alternatives. Hydrogen power was also looked at, as well as lighter vehicles)


I don’t think so. Nuclear fission would have to drive a boiler system which could than drive the drive train and generators. Should be too much weight and too much to go wrong in battle. Plus you need a coolant system and water won’t be readily available. Also the steam cycle is not a closed cycle and you need make-up water.

I had a little Navy Nuke training and a lot of steam cycle training but I am by no means an expert.


Nuclear Tank

Still needs a way to collect make up water but I guess a foward scoop could do the job.

Very limited location use andwasn’t intended as a military Tank, just a giant tank like vehicle.

Why would the steam cycle have to be open? I thought there were closed cycle reactors. How big would a plant need to be in order to run a tank?


It’d be difficult. Not theoretically impossible, but difficult. The problems are power-to-weight and power-to-bulk.

Whether a tank is powered by a big stonking gasoline engine, diesel engine or gas turbine, it is a heat engine. Heat engines generate useable power from a heat differential. You need to have a “reservoir” of high temperature to take heat from and run it through the engine, and a “reservoir” of low temperature to dump heat into. The last is important, and I’ll come back to it.

Most heat engines use a working fluid that is heated and expands to convert heat into work.

Diesel, gasoline and gas turbine engines are internal combustion engines. The combusting fuel acts as the high temperature reservoir. The gases generated by the combustion act as the working fluid. The outside world acts as the low temperature reservoir, and heat is dumped into it simply by exhausting the hot combustion gases.

A water boiler and steam expander (turbine/piston/other), whether heated by combustion or nuclear energy, constitute an external “combustion” engine. That means that heat has to be transferred to the working fluid by conduction. The more power you want, the more heat-transfer area you need. This gives you bulk problems - tanks are heavy and need a lot of power. Internal combustion engines don’t have this limitation - heat is generated within the working fluid itself, there is no need for heat-transfer by conduction.

The other problem is the cold reservoir, which again has to be the outside world. You could simply exhaust the steam to the outside world, but this means that you have to carry water and take on more over time, lessening the advantage of using nuclear power in the first place. It also marks your position with a steam plume, which I guess your average tank crew would take a dim view of.

The alternative is to run the steam through a radiator (effectively a condenser) to dump the heat, recondensing the water so it can be recirculated. Again, this requires heat transfer across the walls of the radiator, and a big radiator is bulky and heavy. Also, where do you put the radiator? The thinner the walls, the better a radiator it is, but you can’t stick a delicate thin-walled structure on the outside of a tank where piffling small arms can perforate it. Instead you have to have the radiator inside the tank, and use fans to suck air in, blow it over the radiator and blow the hot air out again. Fitting this lot inside a current tank is a tall order, and I haven’t even started on radiation shielding…

A large, non-armoured structure like the Antarctic nuclear tank Astro linked to gets around many of these problems. Plus in the Antarctic you have an infinite source of clean make-up water. Similarly, nuclear ships can run seawater over their condensers, and have energy to spare to purify seawater if they need a top-up.

Gotta get me an Ogre ™.

Beautiful answer.

Give me 30 GEVs anyday.

Why? A nuclear-powered tank would have a longer range-without-refueling than a diesel-powered tank, but that’s the only advantage I can think of – and has range really been considered an important operational limit on tanks, up to now?

It’d be cool. Duh.

And then we can mount High Powered Laser and other Energy weapons?

Range is very important for tanks. Diesel powered tanks have a huge supply line travelling along behind them (fuel, mechanics, etc). If the tanks move too fast, not only do they run the risk of runningout of fuel until their suppies catch up, but they also stretch out their supply line which makes the supply line more vulnerable to attack. In Iraq, tanks were forced to stop on more than one occasion because they had to wait for the fuel guys to catch up.

Last I checked, low-profile was pretty important, too… this thing’d be as big as a house. Or a barn, as in, “hitting the broad side of a …”

Sure. Throw in some fricken’ sharks while you’re at it.

Well when they cut the second move down to 3 from 4 the whole “Fuzzy Wuzzy” defense lost effectiveness.

Don’t forget the Dogs that shoot bees from their mouths.

I pretty much said this in the OP…the whole idea came out of a long discussion on how bad the M1 is range wise. Certainly range is a major consideration…or rather the logistics support of these monsters in the field. It has ALWAYS been a major issue. If this was the ‘only’ thing fixed it would be a major improvement…if it could be done. Appearently (at least from the discussion here) we can’t make a nuclear generator small enough to fit inside a tank yet still provide the electrical power to run motors to drive it with a similar performance to todays main battle tanks. We’ll either have to go with smaller, lighter (and thus more vulnerable) tanks like the Strykers or just suck it up and have a huge (and vulnerable) logistics tail to keep these monsters well fed.


Bad news if it’s hit by a uranium-depleted slug.

I read a while ago that the M1 was designed with a particular battle in mind, specifically the Warsaw Pact sending a mass of armor across the border between East & West Germany (the Fulde Gap although I’ve probably got the spelling wrong). In that scenario long supply lines weren’t as much of a concern and so a tank that guzzled fuel but could race like a bat out of hell was a good idea.

I’m not suggesting that the M1 was designed only for that precise situation, just that it weighed heavily in the process.

When the second Gulf War started, I saw some suggestions that the military could have saved themselves a lot of headaches if those M1s were running on diesel engines - they wouldn’t go as fast, true, but they’d have a much longer range and wouldn’t have the same risk of outrunning their own supply lines.