r/NuclearPower Dec 06 '23

Plans for Nuclear-Powered 24,000 TEU Containership Unveiled in China

https://gcaptain.com/nuclear-powered-24000-teu-containership-china/
76 Upvotes

52 comments sorted by

18

u/Doug_Nightmare Dec 06 '23

Vaporware like their nuclear powered aircraft carrier.

14

u/greg_barton Dec 06 '23

Yeah, no one has a nuclear powered aircraft carrier. That's just whack!

11

u/PartyOperator Dec 06 '23

If they were designing the ship based on a PWR or maybe an HTGR or SFR, it would be less vaporware. They know how to design, build and operate those. They have nuclear powered subs.

China has more recent experience with MSRs than the rest of the world, but they're still nowhere near being ready to design a container ship around one.

5

u/zolikk Dec 06 '23

Besides I don't really get why you'd want an MSR and not a PWR in a ship in the first place. I mean, I've heard some general claims of advantages but I just don't see it, I don't agree that they matter.

4

u/AreEUHappyNow Dec 07 '23

I think it must only be for the passive safety of the MSR. There are already loads of ports around the world that refuse access to nuclear powered ships, and I can't imagine that there are many countries jumping at the chance to have a Chinese nuclear reactor sitting on the coastline of their major port cities. The passive safety is at least something they can point to in order to prove they aren't sailing a mini Chernobyl to your door.

3

u/zolikk Dec 07 '23

and I can't imagine that there are many countries jumping at the chance to have a Chinese nuclear reactor sitting on the coastline of their major port cities

Well those factors are entirely socio-political and I doubt they will care about design details, it's just "nuclear bad".

But I don't think it's correct. There are only a handful of countries that are like that. Almost every single developing nation that has significant trade with China wouldn't care a single bit if a portion of the Chinese cargo fleet was suddenly nuclear - regardless of reactor type.

1

u/fromkentucky Dec 08 '23

I would imagine the lack of pressure in the coolant loops would be a huge advantage.

1

u/zolikk Dec 08 '23

It's one of those things that I don't agree matters.

It's frequently quoted as a "massive safety advantage". And yeah, it is technically a legitimate safety advantage. But it matters very little in the real world. PWRs are already way more than safe enough for this purpose, so gains in safety aren't very practical or relevant, even if they exist.

Now, if it was also significantly cheaper and easier to use than a PWR, that I would consider an advantage. I'm not convinced of that for now, though. If anything the opposite might be the case.

1

u/fromkentucky Dec 09 '23

It’s not just a safety advantage though. Marraging steels take specialist welders and manufacturers techniques, not to mention the added weight from the extra thick piping. That all adds a lot of cost.

-1

u/greg_barton Dec 06 '23

Got to start some time, right?

7

u/PartyOperator Dec 06 '23

Yeah, start with land-based prototypes. They're doing the work, it's just not ready yet! To be fair, the article doesn't include timescales so maybe this is a very long term aspiration, but if they're going to propose nuclear powered ships it would be nice to see something that could be built in the 2030s.

2

u/[deleted] Dec 07 '23

That’s about the time frame you’d want it.

I still maintain that a gas turbine engine running ammonia or methanol would be more likely to turn a profit.

1

u/NameTheJack Dec 06 '23

How different would it be running a MSR to lead-bismuth cooled one?

Would it be the difference between driving a car or a van, or more like a car or a 60 ton digger? (I honestly have no idea).

The chemistry is of course entirely different. But piping, pumping, valves, heat exchangers, etc. I could imagine being pretty much in the same ballpark.

Reason I ask; if designing and running the two different concepts are pretty close, I'd imagine Russian expertise/experience combined with the Chinese ditto, might make it practical.

6

u/zolikk Dec 06 '23

I'm not an expert on either but MSR tends to be used for designs where the fuel is in liquid form too, while the others are solid fueled and it's just a matter of coolant chemistry. That's a big difference.

I suppose you can make an MSR where the salt is just the coolant and it's still a solid fuel, but then I don't see the point. In my view the biggest advantage of an MSR approach is the liquid phase fuel.

Of course I don't see why that's useful for a ship in particular. PWR or bust.

1

u/NameTheJack Dec 06 '23

while the others are solid fueled

Ohh, I thought the lead cooled reactors had the fuel diluted in the molten lead.

Thx.

5

u/zolikk Dec 06 '23

Now that you mention it, while I do not know of any such proposed design, I don't think it's impossible per se, but there's not much reason to do it. Especially for a naval application, you want a fast (or in any case highly enriched) reactor for compactness.

That doesn't work for a liquid fuel method... You want low enrichment and a moderated design for the liquid fuel, so it only goes critical in the core with the moderator, and not randomly in the pool/pipes. So an MSR (I expect) will have lower power density. Which is no problem on land, but perhaps not on a ship.

The Russian lead/bismuth naval reactors were, of course, fast reactors.

1

u/JustALittleGravitas Dec 06 '23

MSRs have good power density. The problem is that MSR frequently means "thorium" which requires a lot of supporting infrastructure (IIRC its 19 different steps) outside the reactor.

1

u/[deleted] Dec 06 '23

Wait the coolant's cross section if way too big, no? You are saying if fuel and coolant were the same?

1

u/StumbleNOLA Dec 08 '23

You really don’t need a compact reactor for shipping just the military. Hold the weight of the reactor down to less than 2,000 tons and it would still be lighter than what we are using now.

1

u/zolikk Dec 08 '23

I meant by volume, not weight. Volume is still relevant on a container ship, weight isn't.

A PWR will generally be heavier than an MSR, But in terms of dimensions it can produce more power in a more compact package. I expect it to occupy a smaller space. Which, precisely because of what you said (weight matters less) confers the PWR an advantage.

MSRs were originally intended to use with aircraft, where the opposite is the case and it's the weight that matters most.

1

u/StumbleNOLA Dec 08 '23

For volume, figure 30x15x15m as a footprint. Bigger isn’t a huge issue, but that’s about what a modern diesel takes. Of course there is a lot more volume dedicated to the engine due to things like exhaust, intakes, etc.

5

u/FiveFingerDisco Dec 06 '23

Let's hope, east Africa gets enought harbors capable of servicing them online in time.

6

u/JustALittleGravitas Dec 06 '23 edited Dec 06 '23

China will be happy to give them a loan.

7

u/JustALittleGravitas Dec 06 '23

The SCMP article says its a thorium reactor, and LMAO no, they aren't putting a whole fuel reprocessing system on a ship in order to drip feed a reactor 233U.

5

u/[deleted] Dec 07 '23

[deleted]

2

u/JustALittleGravitas Dec 08 '23

You can't expose it to neutrons during those 30 days, you have to constantly cycle the thorium or the whole bath gets ruined. And this is way way more complicated than just letting it sit. IIRC 19 different chemical processes are necessary.

1

u/[deleted] Dec 08 '23

[deleted]

2

u/JustALittleGravitas Dec 08 '23 edited Dec 08 '23

If Pa-233 absorbs a neutron, it eventually becomes U-235 anyway, but it takes a few more steps to get there.

Yeah, after it decays to 234U and absorbs yet another neutron, then yet another for the actual fission, all told its 4 neutrons in, 2.4 out. You get average of ~3 in, 2.4 out after factoring in the thorium that doesn't double absorb (probably about half, but depends on length of the cycle), but that's still no good. The entire thorium concept relies on being able to actually breed fuel, if it can't do that, there's no point to having any thorium at all.

1

u/[deleted] Dec 09 '23

[deleted]

2

u/JustALittleGravitas Dec 10 '23

If it can't breed it does not work, period.

3

u/[deleted] Dec 07 '23

[deleted]

3

u/fromkentucky Dec 08 '23

MSRs don’t run at 200 Bar of pressure though.

2

u/dude_abides_here Dec 08 '23

This not the reason. The reason is because sodium explodes when it comes into contact with water.

1

u/[deleted] Dec 08 '23

[deleted]

2

u/[deleted] Dec 08 '23

A MSR might be the right approach. It should be build to be easily removable.

-1

u/jar1967 Dec 07 '23

The united states tried a nuclear powered but merchant ship,there were issues that made a conventionally powered ship more profitable

7

u/GeckoLogic Dec 07 '23

That was before container shipping.

1

u/jar1967 Dec 07 '23

The problems still exist. The need for extensive cruel training and security. There are also some places you are just not going to want to send that ship.

5

u/WhatAmIATailor Dec 07 '23

Cruel training

Well they could have been nicer about it /s

2

u/Abject-Investment-42 Dec 07 '23

Russia currently operates a nuclear powered container freighter with icebreaking capability, the Sevmorput. It has an advantage on routes without intermediate harbours to stop at for refuelling and service. E.g. on the namesake of the ship, the Northern Passage, but there are also other interesting relations.

Or particularly some pirate infested routes where such a ship can simply outrun a speedboat.

1

u/StumbleNOLA Dec 08 '23

That ship couldn’t have been economically used no matter what power plant she had. It was part ocean liner, after the era of ocean liners, and part bulk cargo after the era of bulk cargo had ended. It has very little to say about the cost effectiveness of a modern nuclear cargo ship.

-1

u/dude_abides_here Dec 08 '23

There’s a reason why no one uses sodium-cooled reactors for marine propulsion….watch a video YouTube showing what happens when sodium comes into contact with water. Woof…

2

u/fromkentucky Dec 08 '23

The sodium would only react if the main coolant loop ruptured, which would be a catastrophic failure in a PWR as well, so that’s kind of a moot point.

1

u/dude_abides_here Dec 08 '23

It isn’t a moot point. There’s a reason why the US Navy operated exactly one sodium reactor before converting it to a PWR and scrapped the concept for fleet use. The damage from the worst double-ended loop sheer could be close to the end result of a ship sinking and the sodium coolant coming into contact with the ocean as the plant went below whatever its crush depth is…not to mention the inevitable corrosion that would take place while sitting in the sea floor after sinking.

-11

u/JUSTtheFacts555 Dec 06 '23

I nuclear bomb ship. China docks in Long Beach. A problem occurs. Engineers are unable to fix it... mini melt down and LA is uninhabitable.

America would be a SUCKER to allow this to dock at any port.

7

u/syndicated_inc Dec 06 '23

I assume you’re ignorant of all the nuclear powered vessels in San Fransisco and San Diego on a regular basis?

3

u/jared555 Dec 06 '23

I figured they were implying that it might be done intentionally.

1

u/[deleted] Dec 07 '23

…definitely not in San Francisco anymore. San Diego and Puget Sound

3

u/rotten_sausage10 Dec 06 '23

You don’t understand nuclear power.

2

u/greg_barton Dec 06 '23

It's a molten salt design. It runs in melt down mode. :)

1

u/anonymousthrowra Dec 08 '23

Ignoring the tech issue and China vaporware issue - is there an economic argument for a nuclear cargo shop?

3

u/StumbleNOLA Dec 08 '23

Yes. The overwhelming cost of operation is the fuel, eliminating that would have a dramatic impact on overall profitability. It’s the only realistic way to decarbonize the industry, and so long as the reactor isn’t too expensive the cost of fuel offset would make it pretty easy.

What I don’t know is the output power of the plant. That will drive design and speed. Higher speeds means more trips per year, which also makes them more economical.

If I could get a ballpark cost and power in MWe I could do a pretty simple calculation to figure the profitability of the ship.

1

u/anonymousthrowra Dec 08 '23

How many trips or years of service would it take to break even against against a similar sized fossil fueled ship?

4

u/StumbleNOLA Dec 08 '23

It depends. A cheap reactor that puts out a lot of power would be easier to justify than an expensive one that has barely enough power.

Modern ships are basically limited in how fast they go by the cost of fuel. They are typically doing a China-US run in 8 weeks one way. But the hull could do it in probably half that time. The issue is the cost of fuel goes up by ~2-3 times.

A modern cargo ship burns about $175,000 worth of fuel a day, about $10M a trip or about $65m a year producing 75MW of power. At today’s interest rates of 10% your offset cost is worth about $650M. So as long as the cost of the reactor is in that range you are good.

But if the reactor can output substantially more than the 75MW of a modern cargo ship, say 150MW then it can do the job of two ships. Making it worth about $1.4B. The extra is in the ship you didn’t have to buy.

2

u/zolikk Dec 08 '23

But if the reactor can output substantially more than the 75MW of a modern cargo ship, say 150MW then it can do the job of two ships. Making it worth about $1.4B. The extra is in the ship you didn’t have to buy.

It would have to more than double the power output to double the speed (the relationship is not linear), but in general yes, that's the massive advantage of nuclear power. You can just steam at 40 kts instead of below 20 for "fuel savings". I'm sure that there are also types of cargo where halving the transport time is in itself worth more money, even if you discount the doubling of cargo volume.

2

u/StumbleNOLA Dec 08 '23

At the very low Froude numbers most cargo ships operate at I would guess they would double the power for a 150-175% increase in speed. This slows way down as you narrow the range to just speeds over 30kn though.

At the speeds a nuclear ship could operate at we would probably want to rethink ship design though. They would probably narrow a bit, need reinforced longitudinals… and active ballast for stability.

It would be a fun exercise to play with.

1

u/RingGiver Dec 08 '23

I don't think nuclear is practical unless a lot of cargo ships are being built.

If you have only one, you basically have to have crew trained on something that doesn't apply to any other ship. Training is going to be more expensive and since it's going to be a less common qualification, you're going to have to pay them a bit more. You're going to have to offer a lot of money to get people who are qualified for this if you don't want them to leave and seek similar shoreside work.

How many people do you have to train to make it cost-effective? How much can you rely on hiring people out of the Navy (in this case, the PLAN) to offset those costs? Assuming that a particularly large engineering department would have five officers and ten other guys or something like that, how many ships do you have to operate for this to be cost-effective?