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Comment by pjc50 | Hacker News Reader

People underestimate how much of the opposition to nuclear plants in the past was due to the "dual use" nature of the technology, and the proliferation of nuclear weapons. In the 80s it was hard to care about the effects of climate change in a mere hundred years when global policy was to keep civilization-destroying quantities of weapons on hand that could be delivered in 45 minutes.

The war between nuclear weapons and environmentalists went "hot" when the French DGSE sank the Rainbow Warrior and murdered a photographer in retaliation for trying to stop their nuclear testing.

If you think the question is solved, ask yourself this: would you prefer that Iran solve its energy needs from a fleet of nuclear reactors or a fleet of solar panels?

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In 90s, if I remember correctly the Clinton administration even offered to built nuclear reactors in North Korea, if they would only bother to stop their weapons program.

Sort of, but not exactly. They already had at least one reactor[0] and what you are referring to is the Agreed Framework[1][2].

[0] https://en.wikipedia.org/wiki/Nyongbyon_Nuclear_Scientific_R...

[1] https://www.history.com/news/north-korea-nuclear-deal-bill-c...

[2] https://en.wikipedia.org/wiki/Agreed_Framework

They already had one , but US did offer them to build two more LWR reactors, and even I think some work on these reactors had started before being abandoned.

Iran has a nuclear plant and enough uranium that the bottleneck to weapons is enrichment.

I’m not sure what choice of power source has to do with weapon proliferation.

AIUI, one concern with nuclear reactors is what to do with the waste.

A 'breeder reactor' is a type of nuclear reactor that makes more efficient use of uranium than 'light water reactors' and with less left-over radioactive waste.

Sounds great, so why do we build anything else? Well, once you've got a breeder reactor it's a very short step to making weapons-grade plutonium. Whereas with light water reactors, this isn't the case.

So the choice of breeder vs light water reactor has pretty big impact on weapon proliferation.

>one concern with nuclear reactors is what to do with the waste.

Actually, no. The reactor designs in use generate very little waste, just spent fuel rods that have to be kept in safe storage until their radioactivity level goes down to something reasonable. That doesn't take decades, either. The big problem with nuclear waste is the waste from weapons production, and people don't differentiate just like they don't for reactors vs. bombs.

I'm pretty sure I've read articles saying America doesn't currently have a permanent storage facility for nuclear waste such as spent fuel rods, and that the creation of one is politically controversial - have matters changed since I read those articles?

Mostly that for it to matter with any urgency, we'd need to actually be building new reactors. We aren't building them, so we aren't focusing on it and are instead just ignoring the issue. It's not the best decision, but given the problems of today this seems comparatively easy. It just doesn't have much urgency compared to actually building green generation capacity and batteries at scale.

Yet. If we do start building them, they'll probably be small modular reactors instead of the giant old tech ones, and those are both faster and cheaper to build.

They are claimed to be cheaper to build. There is no real world evidence that they will actually be cheaper to build (per unit of power output), and they will likely be more expensive to operate (due to diseconomies of scale in staffing).

Gen III/III+ conventional reactors were also claimed to be cheaper to build. Look how that turned out.

Not really, but bomb waste and spent fuel rods are separate subjects. The volume of fuel rods we're talking about here is small enough that for the most part the spent fuel rods are stored on-site at the plants. Not a great long term solution, especially since the plants don't have facilities designed for it. They're in above ground casks that are lined up in the open spaces around the plant.

However, long term interment isn't what's planned anyway... the fuel rods can be reprocessed into new fuel, and they aren't much of a storage concern anyway... they can actually be stuck on a truck and hauled away in their casks down the highway.

We need somewhere to store the fuel assemblies that's safe and secure (or better than putting them in casks in the open) but we're not looking for a dump site. More like a warehouse facility, where they can sit until reprocessed or dismantled.

Every technology has pros & cons, effects & residues.

Coal : Effect/Pros - Energy/Cheap. Residue/Cons - C02/GlobalWarming

Nuclear : Effect/Pros - Energy/Clean. Residue/Cons - RadioactiveWaste/Contamination.

Where do the nuclear byproducts go currently ? Into the earth? Rivers? Oceans?

30 years ago, we switched from paper based products to plastic, to save trees. Today, we want to switch from plastic based products to paper, to avoid pollution.

Every 'switch' will come with side-effects that the current generation is fine with, because they're not going to be ones dealing with it.

I think it gets dumped off the coast of Somalia, actually.

Obviously, capitalism isn't very good at accounting for externalities, whether they are measured in birth defects, or in degrees centigrade - but I think global warming is a bit more extreme in scale than your typical pollution issue.

>Where do the nuclear byproducts go currently ? Into the earth? Rivers? Oceans?

No where, because there aren't any. If you meant spent fuel if it's not reprocessed it's stored as long as needed to be less dangerously radioactive. If it's reprocessed, any radioactive elements in it that aren't useful are stored and left to decay. Present storage of things like this is on-site as mentioned above, because reprocessing mostly doesn't happen.

The amount of unusable material from reprocessed fuel is tiny, by the way.... even less trouble than storing the spent fuel rods, on the order of a handful of material from a whole fuel rod assembly.

Power generating reactors don't give off anything but electricity, heat, and spent fuel, they are zero emissions.

No, not really. Historically, weapons grade Pu has been produced in dedicated (graphite moderated) thermal reactors, not with fast breeders.

Fast breeders create Pu, yes, but the isotopic composition is poorly suited for weapons.

Actually, Pu from fast breeders is better than the Pu from thermal reactors, since (n,gamma) reactions are less likely on Pu with energetic neutrons.

People also underestimate how much the push for nuclear plants was due to governments trying to sugarcoat nuclear technology, to make it seem less frightening, and to try to make the trillions of dollars spent on nuclear arsenals seem less egregious.

I find it very hard to imagine that a 74 years old technology remains complex enough to be available only to governements.

It's not. Nuclear fission reactors are built by large corporations like General Electric and Hitachi. If these companies wanted to they have the expertise to build a nuclear bomb but why would they unless their governments asked them to?

A huge number of 74 year old technologies are available for $0.75 direct from China.

The fact the nuclear reactor hasn't been miniaturized to the size of a coin and included in every $15 childrens toy to power lights is in large part because of public perception and government regulation rather than real safety/health concerns - there exist plenty of typical household materials that are more dangerous than the safest nuclear materials.

On the other hand, a child swallowing a tiny nuclear plant in the shape of a smiley would be an entirely new experience in the A&E department but that would never happens? would it?. I could see from here the lawyers salivating with a case like that.

Not to mention that those toys would end in a few days in the garbage, ready to be shipped by volume to be burnt ("recycled") in some other country.

>The fact the nuclear reactor hasn't been miniaturized to the size of a coin

But it has, or at least close to:

RTGs[1] weighting a couple dozen kilograms are used in space exploration and in rare cases in cold climates. Their main problem is low power density.

Nuclear pacemakers[2] of just a few centimeters across used to be a thing - long lasting and reliable. Also used thermoelectric generators. Replaced by cheaper lithium-based batteries due to high costs of making the nuclear capsule resilient against various possible sources of damage - like body cremation, car accidents, etc.

Nonetheless we have reached certain natural limit of nuclear fission, and only use of nuclear fusion[3] (or major scientific and engineering break-throughs) could change the status quo. The three main unsolved problems for wide scale commercial deployment of fission power:

1) radiation shielding - right now we only have passive shielding via use of structural materials, weights a lot

2) critical mass for active chain reaction (heavy and requires active management) vs passive generation via spontaneous fission (low power density)

3) operational safety and non-proliferation issues: a fission device requires radioactive material, and radioactive material is by its nature dangerous

Notably all three issues are either minimized or entirely absent for nuclear fusion.

Lastly, in typical nuclear power plant, the power generation facilities are usually of comparable size to, or even larger than, the nuclear reactor building itself - so miniaturizing the reactor would yield only diminishing results. High-temperature superconductors ought to be of some help here.

[1] https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...

[2] https://www.medicaldesignandoutsourcing.com/medtech-memoirs-...

[3] "Typical fuel pellets are about the size of a pinhead and contain around 10 milligrams of fuel." - https://en.wikipedia.org/wiki/Inertial_confinement_fusion

> 2) Critical mass:

Can be dramatically reduced with a neutron reflector [1]. Bare Sphere's [2] can be as small as 6.9cm diameter, and use of a neutron reflector could perhaps reduce that by half or more. 3.5cm is pretty small. Research is still ongoing into reflecting neutrons, and it's possible that some clever arrangement of neutron 'lenses' might allow criticality with almost no mass.[3]

[1]: https://en.wikipedia.org/wiki/Neutron_reflector

[2]: https://en.wikipedia.org/wiki/Critical_mass#Critical_mass_of...

[3]: https://www.isis.stfc.ac.uk/Pages/neutron-reflectivity---int...

Has magnetic shielding been tried for fission? I guess it wouldn't work on neutrons, the same as fusion.

Nuclear technology scales horribly downwards so even in a world that fully-embraced the technology you won't have pocket reactors that do anything more than maybe a power some gimmick accessory. The true power potential of nuclear only comes into affect with full steam boiler-turbine infrastructure, which are large, heavy, and maintenance-intensive beasts; a good comparison would be an early-industrial coal steam boiler from the time before we really understood metallurgy. You'd have those boilers in factories, ships, and trains, and maybe even a small crappy one if you were rich for the home workshop, but nothing you'd carry around.

RTGs can be made small, but they also completely sacrifice the power density of nuclear due to their abysmal efficiency. Their main advantage is maintenance-free longevity more so than compactness or anything.

I think with investment nuclear technology could scale down - the full steam boiler design could maybe even be miniaturized via silicon micro machines type technology, but there might also be avenues for using the photoelectric effect for a more direct nuclear to electricity conversion.

Either way, I can totally imagine someone saying "punch cards and relays scale down horribly - you could never make a small computer".

> Nuclear technology scales horribly downwards

A small steam turbine is an apparatus with about the size and complexity of a car engine. But if it has to be licensed and inspected by the NRC then you can forget about it.

And you could make a little RTG that could power a phone for a decade. Even with the terrible efficiency of thermoelectric generators it would still be much smaller than a lithium battery that could store the same number of kWh, because it's ~10% of the efficiency multiplied by much more than 10 times the power density. The main limit you hit on size is practicality -- why make a tiny, tiny, tiny one that lasts for a month when you can make an only marginally larger one that lasts for ten years?

I'd accept a thick phone if it had a huge battery life. But then how do you perform waste disposal? People are, largely, irresponsible jackasses who would think nothing of throwing old RTGs into the ocean / landfill / other improper decomissioning methods.

Also the potential damage is a lot higher e.g. if you're in a car accident and the RTG gets punctured vs. just a Li-ion battery catching fire. In terms of cleanup and containment.

Using an RTG to power your phone isn't a real suggestion. Lithium batteries can last for a day (especially if you're willing to accept a thicker phone) and the inconvenience of having to charge it while you're asleep is minimal. A more realistic application might be something like military radios where you may want them to keep working for extended periods of time in areas where electricity is not available, and then you have an organizational structure that can take care of proper disposal.

The point is that it's not a scaling problem. It's practical to make an RTG that small as a technical matter.

False dichotomy. Iran can solve their energy needs with a new type of reactor that cannot be used to produce weapons (like the Thorium based reactors being developed). On the top of that, you cannot solve a country’s energy need purely with solar. Finally why picking on Iran? As far as history goes there is only one nation that deployed nuclear weapons in a war situation. This same nation wanted to deploy nuclear weapons few more times, the only reason why they did not is public outrage. You can check these since the records were declassified.

The idea that Thorium reactors cannot make weapons is a persistent myth propagated by an overenthusastic group of non-expert internet thorium proponents. It is part of a wider (and in my opinion misguided) scheme led by Kirk Sorensen to rebrand advanced nuclear as "Thorium". Thorium reactors necessarily breed Uranium 233, which is a phenomenal weapons material. In fact, in 1994, the USA declassified a memo from the country's top weapons designers that you can now read for yourself here [1].

[1] https://www.osti.gov/biblio/79078-fGfEfw/webviewable/

Key quote from the weapons folks is: "If the existing weapons were based on uranium-233 instead of plutonium-239, Livermore would not be interested in switching to plutonium."

See also Kang and von Hippel's famous report (pdf) on Thorium weapons potential: https://www.osti.gov/biblio/79078-fGfEfw/webviewable/

Are you saying that in theory they could switch to uranium-233 based on a single study sponsored by the US government. On the other hand there is overenthusiastic (fixed spelling) group of non-expert internet thorium proponents. This includes Ede Teller, Richard Martin, Alvin Radkowsky and some more.

Wikipedia:

It is difficult to make a practical nuclear bomb from a thorium reactor's byproducts. According to Alvin Radkowsky, designer of the world's first full-scale atomic electric power plant, "a thorium reactor's plutonium production rate would be less than 2 percent of that of a standard reactor, and the plutonium's isotopic content would make it unsuitable for a nuclear detonation."[13]:11[19] Several uranium-233 bombs have been tested, but the presence of uranium-232 tended to "poison" the uranium-233 in two ways: intense radiation from the uranium-232 made the material difficult to handle, and the uranium-232 led to possible pre-detonation. Separating the uranium-232 from the uranium-233 proved very difficult, although newer laser techniques could facilitate that process.

Summarizing some of the potential benefits, Martin offers his general opinion: "Thorium could provide a clean and effectively limitless source of power while allaying all public concern—weapons proliferation, radioactive pollution, toxic waste, and fuel that is both costly and complicated to process.

https://en.wikipedia.org/wiki/Thorium-based_nuclear_power

We should stop going after the potentially cleanest source of energy because a single US government study claims it is possible to produce weapons out of it. Coincidentally the same entity that owns the most nuclear weapons on Earth. Luckily non of the world leading Thorium researchers that stupid the stop the progress, hopefully this way of energy production becomes a reality in our lifetime.

No, I'm not saying that we should not use Thorium at all. I'm saying that the internet claim that thorium reactors cannot be used to make bombs is patently false. It bothers me that there is misguided understanding of thorium that ends up trashing advanced nuclear in general in favor of thorium.

There are 2 true benefits to thorium over thorium: less long-lived transuranics (but more deeply-penetrating 2.6 MeV gammas from Tl-208) and the ability to have a breeder with slow neutrons (less specific fissile inventory, but more problematic graphite).

The major health threat from any nuclear reactor is large early release dose, which is proportional to power level and power level alone (Watts is proportional to number of atoms fissioning per second). In this, Thorium fuel is very similar to Uranium fuel. Long-term waste ends up in a deep geologic repository in any case. Uranium-Plutonium cycle can breed as well or better than the Thorium-Uranium cycle.

I like thorium a lot. I just don't want people relying on stuff that is factually incorrect to promote it. It's easy to promote without being wrong.

If you want a fission weapon, its easier to start with raw granite than convert Uranium from Thorium into a weapon.

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