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Comment by Geee | Hacker News Reader

Someone should build a factory which builds small nuclear plants. These one-off nuclear plants are just a distraction. The ultimate solution is to make floating and 99% automatic nuclear plants. This makes it possible to mass manufacture them in a massive factory with low unit costs, ship them all over the world, and run them scalably with low operating costs. Make millions of them. Include waste-management solution as a service.

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There’s reasons nuclear plants has always been built as huge monolithic structures. Power production scales with containment vessel volume, but many of the costs scale with the area.

It’s inherently cheaper to build big.

Small modular reactors is a huge bet that if you really manage to scale up production to huge numbers, it’ll offset the inherent cost disadvantage with building small reactors. It remains to be seen if that’s the case. I’m quite sceptical, but worth a shot.

Small modular reactors is what we need most. Wind and solar covers most land based electric needs, but a small modular reactor is still the only feasible answer for ocean shipping I've seen. (sail boats do exist, but they have many disadvantages vs an engine)

No way are we giving nuclear reactors to container ships. It makes more sense to build big, safe nuclear plants near airports and ports to manufacture fuel from air using the nearly limitless power from the nukes.

The US Navy fields dozens of nuclear vessels. Has since 1954. No meltdowns. Only two ships ever lost, and not due to reactor issues. Subs can go for decades without refueling.

The US navy doesn't usually run that many ships that haven't been seaworthy for decades. Guess if any private shipping companies do.

They’re the US Navy. You wanna have a civilian ship powered by a nuclear reactor sailing past Somalia? Or pull an Exxon Valdez?

Nuclear materials already move intercontinentally on commercial ships. Somalian pirates can already pull an Exxon Valdez using commercial oil tankers.

Also note that the potential for catastrophic meltdown / contamination is proportional to how much fuel you have on board. If you only have ~3 months fuel for a 20MW reactor, then it's not like a 3-mile-island or Chernobyl situation. There are plenty of modern reactor designs that don't turn into a giant cloud of radioactive smoke under duress, but shut down relatively calmly and safely.

You'll note the Navy does not run nuclear for ordinary surface vessels, just carriers and subs. You should think about that more before suggesting we nuclearize freakin' container ships.

That's mostly because smaller ships don't need as much power as a sub or carrier. The wattage required for a large container ship is about on par with the reactor for a nuclear sub.

No, it's not just that, it's because having nuclear on a ship has massive downsides in terms of cost and risks. There's a reason the only other ships that use them are icebreakers.

If you can resurrect a prime Hyman Rickover and put him in charge of the world's shipping fleet, I would consider retracting my statement. Though even if you did, I think he'd agree with my assessment.

The fact that the US Navy can safely run a large number of reactors not only at sea but with tiny crews under water is mindblowing.

It's not like they can source spare parts from down the road, or call in experts as needed.

> ...production scales with containment vessel volume...costs scale with area...

True, but many of the costs outside of the containment vessel also seem to scale - in ways inherently disadvantageous to big reactors.

This is the gist of the whole thing. The conventionally repeated argument is that bigger is better, but I'm not sure if that's true, all things considered. I don't think it is.

I think that mass manufacturing unlocks a cycle of cumulative improvement through rapid iteration, which eventually leads to way lower costs per energy production capacity. However, scaling energy production profitably requires that energy consumption is scaled as well, i.e. there needs to be new applications which consume a lot of energy, and in general people should be encouraged to use as much energy as possible.

This is sort of how France's nuclear industry works. They made dozens of on-land plants, all based on the same design. The design is something like 50 years old now, but the result was extremely economically competitive and reliable, since the parts were interchangeable (so they could benefit from economies of scale), and workers and training were transferable between plants.

As I understand it, the US has never built the same design more than once (or maybe a few times), so each plant has to be engineered and manufactured from scratch, and all the training, logistics, maintenance schedules, etc, are one-off projects.

NuScale tried that, doesn't seem to work (yet).

- Costs way more than anticipated

- resulting energy costs per kWh more expensive than renewables

- small nuclear reactors found to create more waste

https://www.reuters.com/business/energy/nuscale-ceo-defends-...

That's the motivation behind small nuclear reactors (SMRs). Compared to the larger models, these are more "set it and forget it" type of systems, and with it comes the ability to build them much more rapidly than a traditional plant. Check out NuScale Power's VOYGR SMR, as they are pretty far along in the process.

NuScale is cool, but their reactors don't float. Floating is necessary so anyone can just order one and get it shipped, just by pressing a button on their website. And building on land requires all kinds of permissions.

Most of the world is landlocked, besides, you're not going to dock your precious nuclear plant in the middle of a busy harbor one accident, tsunami or other event away from a serious problem. Big reactors have both an efficiency and a security benefit over smaller ones.

But they're still not cost effective which is why the biggest question with nuclear plants always is 'how much subsidy can we get'.

Couldn't a floating plant be built to be inerently better tsunami proof than land based reactors?

In deeper waters a tsunami isn't very noticeable and we already have proven power cable technology from wind power far out at sea.

Tsunamis are chaotic in nature, you can't really know ahead of time what kind of Tsunami's are possible just like we don't really have upper limits on what ocean waves can be like. All we have is evidence from those events that we've observed. The ocean is an incredibly destructive environment, hard to appreciate from a land based perspective. Ships are basically in continuous maintenance to keep them working and anything that isn't made of a rust proof material is in for a very rough time.

Reactors on various vessels have entirely different working parameters from those on shore and there the consumer is right next to the reactor. But in the case that you sketch you'd have a floating reactor tied to a stationary power grid that somehow is resilient to the worst that the ocean can throw at it. I just can't see that working, even in the short term, let alone over the service life of a typical nuclear reactor.

Ship-borne nuclear reactors have been used for emergency power, but that's not a structural solution and it is also a very expensive one (compared to land based generation that power is quite expensive). So as soon as possible the emergency use is discontinued and it's back to land based solutions.

Off-shore windpower shows the complexity of ocean based power generation quite well and they have a much simpler safety situation, maintenance schedule, degree of complexity and so on. And even there the challenges are far more serious than the land based equivalent.

Some work has been done on floating wind farms:

https://en.wikipedia.org/wiki/Floating_wind_turbine

But the economics are not comparable to those of anchored turbines (either off-shore on on-shore). Likely something similar would hold for nuclear power, that off-shore nuclear power would by default be far more expensive than on-shore nuclear power and that is already economically not feasible without massive subsidies.

I know very little about nuclear plants, but ignoring the usual risks, could it be anchored to the sea floor? Is the floating element necessary? Would there be cooling advantages also?

Yes, it would be basically like an oil rig. Floating, but anchored.

Is this important?

https://spectrum.ieee.org/small-modular-reactors-nuscale

> small nuclear reactors (SMRs)

To be clear, that acronym is for "Small Modular Reactors". Just in case anyone else was confused or thought it was a NATO/OTAN thing.

Westinghouse AP300 is further along as a proven solution than nuscale

I have been hearing about small scale nuclear since I was a kid. Still waiting for someone to successfully build one.

Also, this proposal is challenging due to issues with nuclear proliferation. Nuclear plants will need guards.

One idea is that the reactor is small and mass produced, not the power plant! So at a site similar to one where you have 2-4-6 big reactors now you would put 5-10-15 SMRs, with a similar large scale infrastructure (HV grid, transformers, security, water treatment, maybe cooling towers, etc.), but you can get going sooner as the reactors are standardized, with type-permits ready, which helps in the design and paperwork of the complete site, and the site might be able get going sooner at lower capacity, starting to generate revenue earlier.

this came very close to happening in the 70s but was, ironically, killed by the 73 oil crisis

https://en.wikipedia.org/wiki/Offshore_Power_Systems

Very interesting. I've heard of the russian project, but not this.

I made it onto NPR's Science Friday talking about this very story.

https://www.sciencefriday.com/segments/floating-nuclear-powe...

https://whatisnuclear.com/offshore-nuclear-plants.html

https://en.wikipedia.org/wiki/NuScale_Power

> Make millions of them.

What? Millions of reactors, more or less unguarded, sinkable by storms and what not. The proposition is insane.

Make them unsinkable, or otherwise safe whether they are over or under the water.

I think terror organization like the Hamas would love small moveable reactors

That is just silly. Unsinkable? For real?

This push and consent for nuclear have come out of nowhere. It is manufactured consent.

You mean like the Titanic. That might work.

Well sure, if we can make completely safe in a completely uncontrolled environment(floating in the ocean), small, mass producable by automation and operated with no staff fission reactors, everything would be fine.

Currently any one of these features is either still in its infancy or not even being attempted at all. Expecting a reactor with all of them to show up in time to compete with renewable and conventional nuclear seems fanciful at best.

I think it is actually pretty interesting. I wonder if there could be enough passive cooling to simply dump the reactor core in the case of overheating, providing a failsafe against potential meltdown.

It is not a technical problem. It is a social one. From a safety standpoint having more or less municipally run nuclear reactors is terrifying.

Why? Just make sure that they are fail safe and too big to steal. You could melt a couple down each year intentionally just to prove how safe they are to the public and test them

> Just make sure that they are fail safe

You are essentially saying that "just make them safe and they will be safe".

> You could melt a couple down each year intentionally

Lets keep this on the draft stage please ...

>You are essentially saying that "just make them safe and they will be safe".

Yep, thats the proposal. Do you still find it objectionable if they are safe?

You know the meme about drawing the owl?

The burden is on you to describe exactly how they will be made safe.

That is an entirely different question than IF someone would want floating reactors provided they are safe.

Read through the comment chain

>> What if we could make them safe?

>It is not a technical problem. It is a social one.

Yes, and I'm saying the commenter is simply ignoring the problems. They aren't just social. A nuclear reactor is something that must be controlled and secured, period. That's not because of social pressure, that's because of the reality of the technology. It's insanity to think otherwise.

The point I was trying to make, is that the social problem is problem enough, even if they magically could be made safe.

Ah, fair enough.

Well then clicking this link must horrify you

youtube.com/watch?v=pLBcp3nJlFQ

Clickable link - https://youtube.com/watch?v=pLBcp3nJlFQ

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