How is it safe to have a nuclear reactor on aircraft carriers and submarines when they are a potential military targets?
In: 132
If an aircraft carrier or a submarine gets attacked and sunk then the problem of the reactor is likely to be quite a distance away from anywhere people regularly live. You know, because they will be somewhere out in the ocean. So the reactor will sink with the rest of the ship deep underwater and while it of course isn’t going to be great for the patch of the ocean floor it ends up at, it isn’t a problem for the country that deployed the craft.
I mean… we need to start with “define safe”. If you mean, “is it safe to have something potentially dangerous onboard a military ships” I would point out that there are lots of things on military ships that are either explosive, toxic, flammable, or in some delightful situations all three at once! Military ships, vehicles and people have been carrying some pretty dangerous stuff for centuries at this point, a nuclear reactor doesn’t particularly move that needle much in the scheme of things.
But I assume you’re really thinking about the risk of a ship being sunk and the nuclear reactor being breached. Well good news! That’s not really that much a problem. [See water is a REALLY good insulator against radiation](https://what-if.xkcd.com/29/). So once the ship is done sinking, all the nuclear stuff is kind of just… safely there on the bottom. Compared to (for example) the economic and environmental consequences of leaking a million gallons of oil into the ocean, a nuclear reactor is pretty mild.
But let’s think about this another way – why put something like a nuclear reactor on a carrier? Well… because it means that the carrier can go really really fast, for a really really long time, without any need to refuel! That’s pretty sweet, especially for a navy like the US Navy that plans to operate all over the globe. Nuclear reactors give ships an endurance that is only limited by the flesh and bone crew which is pretty high value.
Well, it’s really not 100%”safe”.. There is quite a graveyard of soviet subs taking nap at the bottom of the sea and leaking radiation.
That being said, I think the US has been operating nuclear powered vessels for the last 50 years without much incident. Submarines are produced with enough uranium to last 30 years without refueling and submarine/aircraft carrier accidents are pretty rare. On top of that most of the info is classified so we don’t really know everything about their operation.
Most vessels have automated safety checks, for example, if the electrical system goes offline the reactor automatically shuts itself down. So in theory if anything knocks power offline while the crew is busy handling a situation, then the reactor takes care of itself on their behalf.
If the vessel is attacked and damaged and sinks, see soviet graveyard comment above. There is no nuclear explosion that would occur and a meltdown will happen underwater so you’re just polluting the sea with radiation (and everything up the chain).
I’d use the words “mitigated risks” instead of “safe” when describing these vessels, to be honest.
How safe is it to have nuclear *power plants* when they could be potential military/terrorists targets?
If a nuclear reactor (or even a nuclear bomb) gets hit by an enemy’s bombs or artillery… it won’t just “go off” in the way that a car’s gas tank would explode in an action movie.
Yes, being bombarded by missiles or artillery is not good for a reactor and would likely lead to the release of radioactive material… but if a nuclear sub or carrier is being (successfully) targeted then that means we’re basically in a WWIII scenario where environmental concerns (or crew radiation exposure concerns) start to seem very small-potatoes by comparison.
A nuclear reactor can kill you in many ways, especially if it’s on a submarine with nowhere to run. (Edit: Modern nuclear reactors are relatively very safe! I’m only listing the dangers here in the spirit of the question.)
A meltdown could obviously be a problem. This is when the nuclear reaction generates so much heat so fast that cooling system can’t keep up and the core melts through its container. This either happens when the coolant system fails or the moderator which is keeping the nuclear reaction slow and controlled is not behaving correctly.
Nuclear subs mostly use reactors that have water as one of the moderators. As water heats up, it actually moderates the nuclear reaction more. This means that meltdowns are unlikely in the reactors most subs use. Also, the control rods in subs are also removed via an electric magnet holding them out. If the electricity fails, the magnet powers down and the control rods automatically insert into the core, shutting down the reaction.
However, even if a reactor is not melting down it can still be very hot (400c) which can obviously create deadly steam or hot gases which can kill you by inhaling them or otherwise burn you to death.
Reactors can also cause some funky chemistry like converting water into hydrogen, which is explosive. This is a problem for many types of nuclear reactors and it’s what caused explosions at Fukushima and it was the fear of a hydrogen explosion that caused panic at Three Miles Island. Reactors can also create poisonous/toxic gases or simply displace oxygen, causing you to asphyxiate when in the reactor area. That’s how the volunteer on K219 died while shutting down the reactor. He asphyxiated when he became trapped in the reactor area and ran out of oxygen in his oxygen tank.
Reactors are obviously radioactive as well but they tend to be shielded and only become a major problem if the shielding is breached and you are standing close to the reactor. Radiation decrease drastically if it is obstructed by anything and the further you are from it. Radioactive contamination becomes more of a problem if the reactor core is blown to pieces and the pieces somehow enter your body (lungs or digestive track) but the core would require being blown to tiny pieces to enter your lungs or digestive track, in which case you’ve got other problems.
The other chance of nuclear contamination from an intact reactor is if the reactor creates radioactive gas as part of the nuclear reaction (basically ionizing radiation during the nuclear reaction might create radioactive gas) and the gas escapes containment. I don’t know the danger level of these gases, whether they can contaminate you easily, and whether we are talking increased cancer risk vs acute radiation sickness vs death. But that’s a risk too.
So yeah, a reactor can kill you in a lot of ways. But during war, a lot of things can kill you.
>“Ryan— be careful what you shoot at, hm? Most things in here don’t react too well to bullets.” Captain Marko Ramius gestured around the nuclear submarine.
>”Yeah. Like me. I don’t react well to bullets.” Jack Ryan replied.
Edit: Soapbox: With all this said, I am pro nuclear power! Yes, nuclear reactors can kill you. But you know what? Fossil Fuels and air pollution kill more people each year than all the nuclear disasters have killed ever, in the history of Nuclear Reactors. So, while Nuclear Reactors can be dangerous, modern technology can mitigate a lot of the danger. And you have to compare nuclear reactors to the alternative. When you do that, wind and solar are nicer than nuclear, but nuclear is much nicer than fossil fuels. It’s all relative and fossil fuels are going to absolutely wrecks us if we don’t move off them quickly.
Some great answers in here, but I don’t see anyone addressing the ‘military target’ portion of the question. Aircraft carriers are some of the most well guarded things on the planet. The US military for example always has them surrounded with many, many other vessels that have a myriad of functions including supply and defense. See: [https://en.wikipedia.org/wiki/Carrier_battle_group](https://en.wikipedia.org/wiki/Carrier_battle_group)
Land based nuclear reactors are likely much easier targets for certain types of attacks.
water is a very potent radiation blocker.
Its why nuclear reactors are submerged in them.
So, when an aircraft carrier or sub is sunk, it’ll sink to a place where the radiation won’t harm anyone except the fish.
Theres a reason why nuclear-powered tanks never took off.
If nuclear powered craft are being attacked and destroyed you can be sure that a little radioactive leak into the ocean is likely to be among the least of our concerns.
The last nuclear ship lost was in 1968. And the reactors went to the bottom of the ocean far away from anyone. That’s a pretty good safety record.
Latest Answers