Nuclear Cargo ships might become a thing again.

[TumbleGeorge]

While I can buy that, I can equally buy that the reasons may have been valid. Have any links making an argument either way?


This is the part that concerns me most. "At sea" it's about as unsupervised as it gets.

Solve that and you have a solid idea.


Is there a source for that besides quora? They are kind of... a bad source, at least.

And even his post notes it's Uranium-238 from a research reactor, not the more commonly employed (I think?) U235 that will mess you up.

Myths busted.

 

[R0H1T]

Is that uranium ore or what?

 

[TumbleGeorge]

Is that uranium ore or what?

Metal ingots.

 

[Count von Schwalbe]

I'll start with the no. You watch too many movies. The dangerous radioactive stuff is heavy, and it is going to sink to the ocean floor and sit there till the end days.

Dissolved in a molten salt, which is partially soluble in water. I would expect it to release a underwater cloud of molecule-scale radioactive particles.

Good for open ocean, where it will dissipate quickly and become little more than background radiation. Bad for confined, stagnant water like ports.

This is one of the main reasons I think a TRISO fuel would be a better option. Those graphite balls would sink like a stone, and would be relatively easy to recover if it was dangerously close to the surface.

And it is not like high-temperature gas-cooled reactors are worse than molten salt reactors. China has multiple HTGC reactors online, but has only achieved proof of concept with MSR reactors.

 

[dragontamer5788]

And even his post notes it's Uranium-238 from a research reactor, not the more commonly employed (I think?) U235 that will mess you up.

U235 isn't "common". IIRC, nuclear fuel is somewhere around 20% U235 or something like that. While nuclear-weapons are closer to 99.9% U235.

The difference of 20% and 99.9% is the difference between a controlled reactor making tons of free energy, and that same reaction going totally out of control and exploding. 20% U235 can still cause issues (see every nuclear disaster ever). But its not a "weapon" until you start pushing for U235 purities way beyond normal.

U238 is a weapon because its heavy, not because of its (very slight) amount of radioactivity. So we use U238 to make tank armor and tank bullets. Also, when you make nuclear fuel, you end up with loads-and-loads of U238 sitting around (you turn natural 0.7% U235 Uranium-ore into 20% U235 by removing most of the U238 from it), so might as well do something with it...

 

[Count von Schwalbe]

From the DOE:

Most commercial reactor fuel uses low enriched uranium (LEU) enriched to between 3 percent and 5 percent 235U. Uranium between 3 and 5 percent 235U is sometimes referred to as “reactor-grade uranium.”

 

[dragontamer5788]

From the DOE:

Thanks.

I knew there was a 20 somewhere with nuclear reactor fuel, but I guess I messed up and thought it was 20% instead of 1-in-20.

But yeah, its the U235 stuff that will murder you with radiation, and is the source of the fissile energy (and in high enough purities: the bomb).

 

[Count von Schwalbe]

LEU is anything up to 20%. Most reactors use lower enrichment, and a bunch now use natural uranium.

 

[Divide Overflow]

How much carbon is emitted in the mining, refining, distributing and disposing of the fissionable material used in these "zero emission" reactors?
Like EVs and their batteries and charging sources, there's more than just what's involved in the engine / reactor.

 

[dragontamer5788]

How much carbon is emitted in the mining, refining, distributing and disposing of the fissionable material used in these "zero emission" reactors?
Like EVs and their batteries and charging sources, there's more than just what's involved in the engine / reactor.

Assuming 5% grade nuclear fuel, 20kg of nuclear fuel is 1kg of U235, which requires 142kg of raw uranium ore to mine and process. (99.3% U238 in the natural state).

The energy that 1kg of U235 provides is equivalent to 2,700,000 kg of coal.

So... the opposite? Its up to you to tell me why you think 142kg of raw uranium multiplies out to 1900000% more externalities than its competitors like coal. Cause I'm pretty sure the trucks that carried those 2700 tons of coal down the mountain used more energy than any of the externalities you care to add up to the nuclear side of the equation.

 

[R-T-B]

Just want to say, I'm not an expert by any means (honestly none of us are but I'm not even a hobbyist lol), just trying to use my "bullshit meter" effectively. Thanks for all the corrections, it is good to learn a bit...

 

[mechtech]

USA, Russia, Japan and some others trialled this decades ago but ports wouldn't let them dock so the ships failed commercially.

Maybe this time around things will be different, as cargo ships are one of the biggest polluters, moreso than cars AFAIK.

View attachment 325115

As soon as they get close to doing it OPEC will drop the price of bunker c or whatever they use and nuclear will go on the shelf again.

Not a bad idea though with SMR and MMR (small modular and micro modular reactor) on the drawing board and SMRs going into service in the near future...........

 

[Totally]

And it is not like high-temperature gas-cooled reactors are worse than molten salt reactors. China has multiple HTGC reactors online, but has only achieved proof of concept with MSR reactors.

That's because MSRs are inherently unsafe to operate because of thermal runaway (as T↑, sk↑) vs all others that are self-limiting (as T↑, sk↓). Nothing scarier than a reactor that naturally gravitates towards supercritical.

 

[ShiBDiB]

Nuclear powered naval vessels have been a reality since 1955 in military use. Enough countries have them. Therefore, we have almost 70 years of experience. Small-scale nuclear reactors are nothing new in this world, although the media is trying to push such publicity materials of some companies that are recently engaged in the production of such reactors.

Ignoring the cost of the reactors themselves. There's a massive cost for the US Navy in training the eggheads to maintain these things.

I do agree that nuclear is the way forward. Just not sure we should be starting the nuclear power wave with cargo ships.

 

[80-watt Hamster]

Ignoring the cost of the reactors themselves. There's a massive cost for the US Navy in training the eggheads to maintain these things.

I do agree that nuclear is the way forward. Just not sure we should be starting the nuclear power wave with cargo ships.

It makes sense to me. Nuclear propulsion at sea is mature tech, so a rollout to to additional oceangoing vessels is a pretty logical step. Cargo ships make the most sense from a practical angle, because nuclear propulsion systems are expensive, so you'd better plug them into something that can greatly benefit from them.

 

[ShiBDiB]

Cargo ships make the most sense

Not really when you consider things like a large list of ports that don't allow nuclear vessels, security risks both in and out of port, lack of trained crew (or even a training pipeline outside of the military for shipborne nukes), crew vetting as a whole will need to be completely re-looked at with a ton of mariners now getting disqualified. Just because military/state owned vessels have been doing it doesn't mean it's feasible for the civi side.

 

[80-watt Hamster]

Not really when you consider things like a large list of ports that don't allow nuclear vessels, security risks both in and out of port, lack of trained crew (or even a training pipeline outside of the military for shipborne nukes), crew vetting as a whole will need to be completely re-looked at with a ton of mariners now getting disqualified. Just because military/state owned vessels have been doing it doesn't mean it's feasible for the civi side.

Those are all human factors, and while real obstacles, are also surmountable. There may very well be more-practical applications for nuclear generation that we're not already doing, but I maintain that cargo vessels, from a technical standpoint, look like a pretty good one.

 

[Count von Schwalbe]

My personal guess is that the first practical nuclear cargo ship will have a Generation 6 reactor, not a Generation 4.

 

[freeagent]

It is probably better than the fuel they are using now. I don't want to say we have mastered the tech, but I am sure it is much safer now. I heard there is tons of nuclear waste sitting at the bottom of the Atlantic. Everything from full on decommissioned nuke subs, to old unwanted reactors.. plural, as in a lot. So between that and Fukushima I don't eat fish

 

[dgianstefani]

I guess at some point you have to choose between huge emissions or the slim risk of a small nuclear contamination. Remember navy reactors are much more powerful.

Personally I would have chosen cutting global carbon emissions by a significant percentage in the 70s when this tech was proven rather than 50 years of more emissions and water pollution from fuel oil etc than all cars combined, but that's just me.

 

[iameatingjam]

Well honestly, given the current outlook on climate and sea levels rising, getting more experience of anything on the water seems like a pretty good idea.

Can't see any trajectory right now that says we're fixing climate. Pop still growing, usage per pop still growing, and no trend of it turning either. I wonder how wrong things must go before we change. And if we can even change.

Even the Biden admin, with a pretty successful climate agenda and investment... is not working on reduction or transition. Green and reneweable is just on top of fossil.
In the EU, we're building like mad and actually transitioning for a large part.. but we also can't say we have answers for everything that's phased out with fossil. And realistically: we're building. We're not doing less. We're doing more, just in a different way.

I think nuclear is unavoidable. We probably should just shoot the waste off to a distant rock in the cosmos at some point? Oh by the way, what powers those rockets actually

Nah all you have to do is drill a really deep hole. Its the safest way. And most nuclear waste isn't what people think of anyway, its like used gloves with a tiny bit of radiation on them.

lets say the nuclear powered ship runs perfectly with no engine issue...
how about when the hull is damaged or its sinking... what then? wouldnt the radiation leak out into ocean?

You, uh, ever heard of oil spills?

 

[Chrispy_]

lets say the nuclear powered ship runs perfectly with no engine issue...
how about when the hull is damaged or its sinking... what then? wouldnt the radiation leak out into ocean?
water flows and the current will travel far and not just damage to the surrounding area...
this is a chinese company and they are all about profit... the zero emissions is just to please the press...
im sorry to come across as negative but i dont have a lot of confidence in the chinese to manufacture this to the safest level as possible...

Nine nuclear-powered submarines have been destroyed. Their wrecks have been investigated or (partially) recovered. The reactors are failsafe and damn-near indestructible - the reason for most of the nuclear power station accidents has been cooling failures - water wasn't able to get to the reactor to keep it cool, so it eventially melts the control rods and uncooled reactor vessel. I think in a sinking ship or submarine there's no risk of it running out of water!

Nah all you have to do is drill a really deep hole. Its the safest way. And most nuclear waste isn't what people think of anyway, its like used gloves with a tiny bit of radiation on them.

There are even natural uranium "nuclear reactors" underground that have been discovered where reactive isotypes have started fission by simple geological proximity. Radioactive rocks deep underground aren't limited to what mankind has produced.

 

[iameatingjam]

There are even natural uranium "nuclear reactors" underground that have been discovered where reactive isotypes have started fission by simple geological proximity. Radioactive rocks deep underground aren't limited to what mankind has produced.

Yeah I actually have heard about those. Very cool.

 

[dgianstefani]

eVinci™ Microreactor | Westinghouse Nuclear

Westinghouse is currently developing the eVinci™ Microreactor, a next-generation, very small modular reactor for decentralized remote applications

www.westinghousenuclear.com

This doesn't even need active water cooling. Basically a nuclear battery.

 

[R0H1T]

Will they lend one for school projects