1MW Molten-Salt Test Reactor by Copenhagen Atomic for €88k [video] | Hacker News Reader

1MW Molten-Salt Test Reactor by Copenhagen Atomic for €88k [video]

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234 pointsjbverschoor198 comments

To the best of my understanding, one of the main reason that MSRs have not gone to market is that the salts are so corrosive that containment over the long term is not currently possible. Note the questions about materials, alloys, and flow sensors in the video.

ORNL had fully functional reactors in the 60's, but those reactors were only safe to operate for a few years, and they were at lower temperatures than what we are targeting today. Liquid fluoride thorium salts at 700+ C will readily dissolve chromium, which makes working with stainless very difficult. Other common alloying agents are susceptible to radiation (Co & Ni transmute when irradiated) which further shortens the lifespan. There is also the issue of tritium, which can permeate stainless steels, cause embrittlement, and escape into the environment.

ORNL developed Hastelloy N to help address these issues, and there is an effort to certify other structural steels to for use in reactors (316H, 800H, inco 617). None of the studies that I have seen indicate that any of these metals will survive for more that 5 years or so.

> To the best of my understanding, one of the main reason that MSRs have not gone to market is that the salts are so corrosive that containment over the long term is not currently possible.

I've wondered why "long-term" is such a huge criteria. One of the biggest nuclear issues today is using them way past their lifespan because they are so expensive to build.

Let's assume molten-salt is cheaper to build and less dangerous (from a radioactivity point of view). Why not make expendable designs? Make them smaller so the building requirements are easier. Make them easy to remove and replace. Ease up on the restrictions a bit so they can be replaced every 5-10 years instead of decades.

Long-term mass production has tons of advantages. Costs per unit decrease. Defects per unit decrease (this is part of cost per unit usually, but not if a defect gets through inspection). Recycling used units should radically decrease material costs when getting close to peak reactor count (chain of custody paperwork from mine to installation in the nuclear plant is why an otherwise $0.15 screw winds up costing $50-100). Constant employment will build experience over many years and further decrease errors. Once the site design is finalized and enforced, the reactor design can be gradually improved and given the short lifespan, efficiency will increase a minimum of every decade. Likewise, design mistakes (once caught) will only be around a decade at most instead of a half-century like we see today.

Kibitzing outside of any expertise that I have, here, but thorium reactors are generally regarded as a significant nuclear weapons proliferation risk. This has been an inhibiting factor with regards to investment in research.

This design — cheap and transportable in a standard shipping container — significantly ups the ante on that risk, to put it mildly.

Deployed singly, small, low-power, short-lifespan reactors would increase the burden of maintaining regulatory control over those reactors — destined, by design, for catastrophic failure unless they are retired within a safety period — which in turn would the risk of a nuclear contamination incident. This could be mitigated by operating the reactors in banks at a containment/maintenance site.

I'm not sure what parts of the reactor could be usefully recycled. All the metals would be embrittled by neutron bombardment.

I'm just recalling from the Sorensen's LFTR's videos here, but I had the impression it was the exact opposite in terms of weapon-grade nuclear material.

Anything you take out of a Thorium-fueled reactor is going to contain Uranium-232 and its decay products, which emit easily-detectable and dangerous to nearby living things gamma radiation. U-232 is much harder to separate out from the useful U-233 (which is the fissile fuel that Thorium is converted into) than Uranium 235 is from Uranium 238, so it is very hard to extract clean safe fissile material from a Thorium reactor.

This means that a Thorium reactor is really hard to get material from for a nuclear explosion. Any material you do extract is going to be screaming "I'm over here" to any nearby gamma ray detector, and will be dangerous to handle.

But if you just wanted to make a dirty bomb by blowing up a small Thorium nuclear plant with conventional explosives, spreading highly radioactive material all over the place, that sounds much more feasible.

> Kibitzing outside of any expertise that I have, here, but thorium reactors are generally regarded as a significant nuclear weapons proliferation risk.

Also outside my expertise, but everything I read said the opposite. Wikipedia (which gets true/false questions wrong half the time) says (emphasis added):

Uranium-232 (232 U) is an isotope of uranium. It has a half-life of around 68.9 years and is a side product in the thorium cycle. It has been cited as an obstacle to nuclear proliferation using 233U as the fissile material, because the intense gamma radiation emitted by 208Tl (a daughter of 232U, produced relatively quickly) makes the 233U contaminated with it more difficult to handle.

https://en.m.wikipedia.org/wiki/Uranium-232

PS, HN, Y U NO blockquote?!?!

>PS, HN, Y U NO

IKR?

>so they can be replaced every 5-10 years

Recycling of highly radioactive materials, aka the entire reactor vessel every 5 years, is cost prohibitive.

That short of a lifespan will create massive amounts of waste to deal with.

Most of the by-products decay away much more rapidly in thorium reactors and the rest are super easy to detect. This should have recycling easier (let it set for a few years after powering down then recycle it necessary). If each unit fit into a slightly oversized shipping container, safely transporting it doesn't seem more difficult than transporting in nuclear material in the first place. Plus, since waste is going right back into a new containment, it probably doesn't have to be as clean provided you can keep workers safe.

Actually I did a Ph.d. related to chemical separations of nuclear materials. Granted my direct research was narrow on some aspects of solvent extraction related to actinide separation, but I did get a general impression of other areas from hearing stories and presentations at conferences and such. My impression is that you're vastly underestimating the complexities and challenges of those steps. Yes, this is just an appeal authority type argument, but your point is a lot of generalized high level statements without supporting evidence. What you're saying could be true, but from my impression it's more likely to be magical thinking. I'd love it to be true, but just because we want something to be true or it sounds nice doesn't make it more likely. In fact, we should double our due diligence for claims that tell us what we want to hear.

I agree. But, in a molten-salt reactor, the vessel and heat exchangers are equivalent to fuel assemblies. Dispose the vessel and heat exchangers similar to Zr-clad million dollar fuel assemblies.(PWR/BWR reload costs $60-100 million per 12-18 months.)

Material wise Zr clad is way more expensive than stainless 3XX & graphite combined. Even if Ni-alloy is used in disposable MSRs Ni-alloy+graphite will be slightly cheaper. (Base metal costs: Zr metal: ~$22,700/ton Ni metal: ~$13,100/ton)

Many actinides have volatile fluorides. Fluoride volatility is a proven process used to enrich uranium for LWRs. Fuel salt can be disposed after recovering U & Pu. Vacuum distillation is physical separation, which can also be used to further recover expensive base salt FLi7Be. No vacuum distillation is necessary if inexpensive salt is used.

My guess would be this: the cost of a reactor dominates the cost of electricity for fission, so making a reactor last longer reduces the time-averaged cost. Typically, reactors are expected to pay for themselves within 10-20 years. So, a reactor that self-destructs in 5 years needs to cost 2-4x less. It's not clear that MSRs have that kind of up-front cost advantage.

A recommended video to watch explaining corrosion protection:

https://youtu.be/jO37sMRqv8o

hard not to cringe at the safety standards in that video...

> One of the biggest nuclear issues today is using them way past their lifespan because they are so expensive to build.

Or they're trying to avoid the staggering and bankrupting cost of decommissioning them.

A similar issue exists with metal coolant reactors, which conceptually would be very simple, and would use proven technology, fuel rods and cladding and have similar or better operating characteristics to molten salt: low internal pressure, high temperature, inherent safety (fuel is physically separated from colant and never touches internal piping, pumps etc.)

It's very hard to formulate a metal coolant that has low melting point (pure lead is already too high), does not react with air or water (Sodium cooled reactors are notorious), has low cross-section (Hg fails), does not activate under the neutron flux to long lived chains (Bismuth and potassium in eutectic alloys) and does not dissolve the steel structure of the reactor (Tin).

If this problem could be fixed and have a safe, inert metal coolant with good thermal characteristics, fast breeders would become common place.

Aren't they already used in Russian submarines?

They were used and the design was modified into small portable nuclear reactor, the SVBR-100, a 100MW(e) reactor that can be sold containerised and delivered on a rail flatcar.

The problem is that a) the project owners have issues getting money to finish certification b) we don't mine enough bismuth.

The second problem is pretty major issue, because as far as I know, we don't actually mine bismuth - all the bismuth available worldwide is from processing of tailings in other mines, and isn't under any kind of high production rate.

Making just a dozen or so reactors for submarines was easy. Making mass-production line would actually mean a noticeable drain on world-wide supply of bismuth!

Then there are political problems involving buying russian tech.. :(

They are, but this is because the Soviet designers thought that the improvement in power density were worth the serious disadvantage of having coolant that freezes well above room temperature.

Yes, exactly.

Making a working reactor is as easy as disoling a critical mass of uranyl nitrate in a bucket of vodka.

Making a lasting reactor that will work non-stop for years is not so at all.

This is why I am sceptical about this. Solid fuel is by far more troble free, even if it doesn't last that long.

Makes me think of Oklo:

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

Why use stainless steel? I thought "stainless" is mainly useful because it doesn't rust (is there water & oxygen in a MSR?). Also, couldn't the steel have another layer inside (e.g. just iron or something else non-reactive) so that it never comes into contact with the salts?

For many of the same reasons that Spacex is using it for their starship. It's cheap and readily available, relatively easy to work with, and very well studied. There also really are not that many materials that have passed certification for use in reactors. I believe that "BPVC Section III-Rules for Construction of Nuclear Facility Components-Division 5-High Temperature Reactors" only covers half a dozen stainless steels.

As for cladding, the DOE's 2021 budget includes money for testing novel claddings. They are also looking for robust redox reference electrodes and additive manufacturing methods.

"Rust" is just oxidation and there are a lot of substances that will cause oxidation.

To add to this, temperature plays a really critical role in oxidation/corrosion of stainless steel (and other metals). The scale that forms at high temperatures has a different composition than what develops at lower temperatures. In certain environment, the scale remains on the surface, inhibiting further oxidation, but in other environments, the scale is continuously removed, eventually destroying it.

Iron is vastly more reactive than stainless steel, that's exactly why we have stainless steel.

The corrosion problem has been blown way out of corrosion, and I suspect, you're confusing it with the graphite swelling problem.

Pure nickel won't corrode in fuel salt, so to a first approximation, Hastelloy N works fine and lasts forever. Chromium is dissolved superficially, but this process is self-limiting. Two more corrosion mechanism were identified: some nickel transmutes and releases helium, which migrates to grain boundaries, and the fission product tellurium reacts with the metal. Solutions for both problems were identified by 1974, but never tested, because the MSR program was terminated.

What is more likely to limit core life, is the graphite. Graphite, when irradiated, first shrinks, then swells. MSBR had a very complicated core made of precisely manufactured graphite pipes. These would crack and deform, and then they need to be replaced. Everyone who is considering a graphite moderated core seems to plan for a long life of the pot and a four year life of the graphite inside it. Copenhagen Atomics plans to use heavy water for moderation, so there is no graphite to worry about.

You're correct. The vessel & primary heat exchanger of a MSR which are in contact with liquid-fuel is equivalent to fuel assemblies of many solid-fuel reactors. In solid-fuel reactors the clad which is designed to contain fuel doesn't last long. Similarly, in MSRs the materials in contact with fuel doesn't last long.

So, we need to dispose the vessel and primary heat exchangers similar to Zr-clad million dollar fuel assemblies.(PWR/BWR reload costs $60-100 million per 12-18 months.) Material wise Zr clad is way more expensive than stainless 3XX & graphite combined. Even if Ni-alloy is used in disposable MSRs Ni-alloy+graphite will be slightly cheaper. (Base metal costs: Zr metal: ~$22,700/ton Ni metal: ~$13,100/ton)

Why not use a stone type of material. Like a furnace?

There are a few reasons, but the biggest one is that ceramics and composites also react with the molten salts. One study from 2015 (1) showed that even testing the corrosion resistance of metals was difficult because the type of crucible used had a large effect on the results.

These systems need pumps at a minimum. Sensors (temp, ph, flow rate, chemical composition, etc.) are also very important for prolonged, low maintenance use. These cannot be made of ceramics (that I know of)

The container will also need to safely hold a dense pool of molten salt. The linked $88k test reactor has a capacity of 350 liters, which at 1.94 g/cc is ~680kg/1500lbs of Li2BeF4.

Another important reason is that heat transfer is the whole point of the reactor, and most metal alternatives have poor thermal properties.

1. https://www.researchgate.net/publication/282433901_Impact_of...

I know on boats they use a piece of sacrificial metal (Anodes) that corrodes more readily than what the boat is made of. This prolongs the life of the boat. Maybe they can use something like that in this situation too.

no, because you would have to let the molten salt react with the sacrificial metal, introducing a lot of complicated impurities into your salt bath that may influence your reactor in numerous ways.

...unless the sacrificial material is a component of the salt anyway, like Beryllium.

ORNL proposed to have a Beryllium rod in contact with the fuel salt. It isn't needed to prevent corrosion of Hastelloy N in clean fuel salt, but it was intended to scavenge the fission product Tellurium, which was found to otherwise cause corrosion.

Doesn't quite work. It's also used in water boilers and most of them corrode after 10 years with the anode in good shape.

Furnaces use stone because it is not very sensitive to heat. Stone generally remains sensitive to acid.

Plastics would be great to withstand the acid, but they're sensitive to heat.

Ultra-high-temperature polymers might get there. There are polymers used in specialized industrial applications that can handle ~500° C.

Granite, for instance, has a 1200c melting point which sounds good. Its large grainy structure might cause porosity issues. And it's main constituents are silicon and aluminum, both of which do transmute under neutron bombardment. (An expert could say if they transmute to anything you really don't want around, and how long it'll be there.)

I think ceramics are an answer to the porosity and similar issues. Consistent structure, no inclusions or other weaknesses. But they would face the same transmutation and induced radioactivity problems as stone of the same material.

Ceramics used in water boilers crack. You don't want that in a nuclear reactor.

You mean ceramics?

There are so many to chose from, and most are unusable for one reason or another. The leading candidate being investigated is carborundum (silicon carbide). It doesn't corrode in molten salt, it low appetite for neutrons, is reasonably easy to manufacture, conducts heat fairly well. It's even mentioned in the video.

Is there a reason except price that titanium isn’t used? It has a higher melting point than steel and resists acids.

I think you have to have oxigen present for it to be corrosive. Can't they vacuum it?

From an engineering standpoint any chemical reaction that changes the properties of a metal in an unwanted way will be called corrosion. It is something to prevent and/or monitor that will inevitably shorten the lifespan of the metal part. (Non-metals like fiberglass can also "corrode".)

You need an oxydizer whatever it is. Oxygen is only one oxidizer. Chlorine, fluorine and the other halogens are oxidizers too.

Fluoride (with a 'd') is not fluorine (with a 'n'). The difference is as big as that between sodium and sodium chloride. You can eat one, but not the other.

The most powerful oxidizer in MSR fuel salt is the U(IV) ion.

IIRC fluorine is/can be a more potent oxidiser than oxygen.

"Corrosion is a natural process that converts a refined metal into a more chemically stable form".

Oxidation is the most well known form of corrosion, but there are many other corrosive reactions out there.

https://en.wikipedia.org/wiki/Sulfide#Corrosion_induced_by_s...

To contain molten salt use solid salt.

Would diamond do better?

Diamond will burn like super-expensive coal. Probably not ideal for those temperatures.

Umm, that's doubtful. This isn't oxygen that generates a gas on reaction. You would need to look at the actual conditions at moderate temperature (800-1000F is only ~400-500C) for metal fluorides in contact with diamond films and carbon solubility. Even fluorocarbons tend to actually be moderately stable in these temperature conditions.

Diamondlike film coatings should last longer than carbon or graphite crucibles (since those materials are far softer). Those have been tested, although it would seem that high nickel (rather than floridizing Cr) steel is probably the prefered material. SiC also works and they discuss this, but there are concerns about Tritium absorption for the larger crystal structure and porous sintered components.

For some comments and measurements, see this thesis on metal fluoride corrosion control for reactors: http://fhr.nuc.berkeley.edu/wp-content/uploads/2014/10/06-00...

research on SiC also continues: https://www.osti.gov/servlets/purl/1531263

I didn't see €88k in the video... but I did find it on Amazon!

https://www.amazon.com/Molten-Salt-Loop-40-Liter/dp/B077782Y...

$88,000 + $4.49 shipping.

If you look at the brochure pictures you'll see that that they wrote "two layers of contaminant" instead of "two layers of containment", which is unsettling to me.

My guess is English is not their first language + autocorrect.

I like that Amazon says, "People also buy 'Diamond Crystal Kosher Salt' when buying this product." AI recommendation fail.

Maybe they do?

Gotta love the "Customers also viewed these products" section on that page, for example:

"Salt Block Grilling: 70 Recipes for Outdoor Cooking with Himalayan Salt Blocks"

I've heard that molten salt sous vide cooking is starting to really take off.

I still prefer nuclear.

At 80 seconds in the video he states they sell it for 88k

Thanks

https://youtu.be/A9zfYTWjZqk?t=80

"That's a bargain" :)

Tbh. That looks badass to have in your garage

> Cloud Data Acquisition

Is this the most expensive IoT?

amazingly cheap shipping for 900kg device.

and then you can resell it I assume ("used but in good condition, minor wear & tear, hardly noticeable leftovers of thorium salts")

To clarify, this reactor doesn't have any thorium or any other radioactive elements in its core. It's for testing before they get to "the nuclear part".

Don’t forget to sign the petition at https://start.thorium.today

Pass on that. Solar and wind are already clapping nuclear in LCOE, and before you can rip out the nuclear battlecry, "But BASELOAD", storage costs are in freefall too.

Storage costs, despite being in freefall still are still in the hundreds of dollars per kilowatt hour range. And it's kind of moot since the total amount of storage produced globally is still a fraction of what is necessary to make renewables feasible as a primary source of power. To put this in perspective, the US alone consumes about 500 GWh of electricity every hour. The entire world produces about 300 GWh of lithium ion batteries every year. It's dubious whether electrochemical storage will ever be able to match the requires scale, hence why a lot of renewable proponents turn to experimental solutions like the Sabatier process, hydrogen storage, or things like cranes lifting weights.

https://gspp.berkeley.edu/news/news-center/the-us-can-reach-... ("The US can reach 90 percent clean electricity by 2035, dependably and without increasing consumer bills")

https://www.2035report.com/

https://www.2035report.com/data-explorer/

"The target year of 2035 allows sufficient time for most coal and gas plants to recover their fixed costs, thereby avoiding risk of stranded costs for consumers and investors, if the right policies are in place. Wind, solar, and battery storage can provide the bulk of the 90 percent clean electricity. The report finds that new fossil fuel generators are not needed. Existing gas plants, used infrequently and combined with storage, hydropower, and nuclear power [my note: existing, not new, nuclear], are sufficient to meet demand during periods of extraordinarily low renewable energy generation or exceptionally high electricity demand. Power generation from natural gas plants would drop by 70 percent in 2035 compared to 2019."

That's US centric; Australia is targeting 100 renewables by 2032, using only hydro, renewables, and storage. Let's not say it can't be done while it's being done.

https://reneweconomy.com.au/australia-could-be-100-renewable...

Academic papers claiming feasibility decades from now is a vastly different thing than something actually being feasible. If it were, then we'd have all been using fusion power since the 1980s.

If you prefer a global approach as opposed to a US-centric approach, then consider the fact that the world consumes 60 TWh of electricity per day, or 2.4 TWh per hour. By comparison the entire world only produces 300 GWh, or 0.3 TWh of lithium ion batteries. And only a small fraction of that is used for grid storage [1]. These plans for intermittent sources as a primary source of energy are contingent on vast - 3 or 4 orders of magnitude at least - increases in the production of storage capacity. This isn't something that can be relied upon. This is like pointing to Moore's law and developing an application assuming a 4 THz CPU is going to be around 10 years from now.

Lastly, I can't help but appreciate the irony of complaining about a US-centric approach and cherry-picking Australia - a country with lots of undeveloped land and huge solar power potential - as an example. Like I said in my previous comment, the bulk of global energy consumption occurs in North America, Europe, and Northern Asia (China, Japan, Korea). These places have much lower solar potential between greater inclinations of the Earth and less amenable weather. And even with it's natural advantages, Australia still only generates 7% of its electricity from wind and solar each.

By comparison, the US already generates 20% of its electricity from nuclear and several countries like France, Ukraine, and Belgium are majority nuclear generation. Nuclear is by far the best proven way of delivering carbon free energy, save for hydroelectric power but the latter is geographically dependent. It's more expensive than fossil fuels, nobody denies that, but it's actually doable with current technology. Its feasibility is not contingent on orders-of-magnitude improvements in key technologies. Using nuclear for the bulk of energy generation has been done by multiple countries, we merely need to walk in their footsteps.

1. https://energycentral.com/c/ec/world-battery-production#:~:t....

You are of course free to your opinion, but the economics and cost decline curves of renewables and storage are clear [1].

The entire world is transitioning to electrified transportation, and is going to scale up energy storage (battery manufacturing) accordingly [2], faster than any commercial nuclear operation will be built. Can you build a nuclear reactor in less than a decade cheaper then storage and renewables? The evidence indicates no. But if you can, the world would love that, just demonstrate it's possible. Until then, it's hydro, batteries, renewables, and demand response full speed ahead.

[1] https://www.lazard.com/media/451419/lazards-levelized-cost-o... (Lazard LCOE 2020, pages 3 and 11 are most relevant to our subthread discussion)

[2] https://energycentral.com/c/ec/world-battery-production ("As of Dec 2019, the number of lithium ion battery megafactories in the pipeline has reached 115 plants. The world’s leading EV and battery manufacturer added a huge 564GWh of pipeline capacity in 2019 to a global total of 2068.3GWh or the equivalent of 40 million EVs by 2028.")

Levelized cost of energy in your link excludes the cost of storage. For the third time, nobody is arguing that raw renewable generation isn't cheap. The issue is that translating raw renewable generation into usable, dispatchable power is very, very expensive.

Yes, we absolutely can build nuclear in much much shorter time than renewables plus storage. I don't think you fully comprehend the staggering mismatch between the scale of storage required and storage produced.

We cited the same source on battery production. Take a closer look at the graph: https://www.nextbigfuture.com/wp-content/uploads/2020/02/blo... The small magenta segment that says "stationary storage" is the portion of battery production actually going to renewable storage. Even by 2030, it's still being added at a rate of less than 200 GWh per year. The world uses 2,400 GWh of electricity per hour. That's more than the entire height of this graph. It'll take well beyond 2035 to even provide just one hour of grid storage with batteries.

By comparison, France increased it's share of nuclear generation from under 15% to over 80% in 15 years: https://en.wikipedia.org/wiki/Nuclear_power_in_France#Messme...

France may not be the best case.

France in the end of the 60's nuclearized its gridpower production.

This 'success story' led to a state law (2015-992, from 2015, the "loi relative à la transition énergétique pour la croissance verte", see https://www.legifrance.gouv.fr/loda/id/JORFTEXT000031044385/... ) stating that the part of nuke-produced electricity must fall to less than 50% in 2025, from 72% then, and that renewables must replace it.

In France nuke-power is backed by gas (which produced 10,3% of gridpower in 2017).

The sole reactor currently planned (Flamanville-3) is a complete disaster, more than 10 years behind schedule and 4x overbudget. https://en.wikipedia.org/wiki/Flamanville_Nuclear_Power_Plan...

Lazard has levelized cost of storage analysis too: https://www.lazard.com/perspective/levelized-cost-of-energy-...

And the levelized cost of PV + storage as per that link is $250 to $600 per MWh. By comparison the cost of nuclear in that study is $130 to $200 per MWh. Thank your for providing this source explaining how the cost of storage renewables at a higher net cost than nuclear.

The learning curves of both renewables and storage are such than the advantage won't last long...

> Can you build a nuclear reactor in less than a decade cheaper then storage and renewables? The evidence indicates no. But if you can, the world would love that, just demonstrate it's possible.

Sure, the USA got to the moon in less time, in the 60s. As a technical problem it's easily doable. Even in quantity it could probably be done. (There are some questions of making many of the larger parts at once, such as the containment vessel, and if enough factories remain which are capable of it - in the USA. If it was worldwide, that's not an issue because China now has that capability.)

On the political side, it's either impossible or pretty easy, depending on the motivation. It's currently impossible because of the nuclear boogeyman and all of the obstacles that opponents can throw out. (It is implied that these obstacles have no ultimate merit.)

However, if we had a focus on pollution-related deaths, which are like a never-ending global pandemic - 10k deaths per week from coal pollution alone - then we'd probably find the will to fix it.

Considering that (estimated lifetime) deaths by all Nuclear (including Chernobyl and Fukushima, but excluding bombs) are less than one week of pollution deaths, it'd be an easy sell if we actually looked at numbers.

In the Lazard study, do you see what they budgeted for non-panel costs in utility-grade solar? In residential the cost of the panels is often quite a lot less than the total system cost.

> Until then, it's hydro, batteries, renewables, and demand response full speed ahead.

Hydro is almost tapped out, and not carbon neutral. But I agree we should build it everywhere possible because it is dependable, and comparatively cheap.

Batteries are not gonna happen for grid-scale power. A few terawatt hours (a minimal estimate for the USA's storage needs) would be every battery produced in ten years, even with a ramp-up, and the pollution from the mining and manufacture would be huge. They're a great solution for certain storage solutions though because they're solid state unlike flywheels and pumped hydro storage. Places where convenience weighs heavily will adopt batteries.

Renewables are absolutely the answer - as much as they are. Any generation that can be peaky, should be solar and wind if possible. Like if we built desalination plants they'd be a great use of intermittent power. Or if they're just charging the storage layer. Neither is free of pollution though, like batteries they merely front-load it and appear green when operating.

You're 100% right though about full speed ahead. I'd rather start on solar today, which I don't fully believe in, than spend years arguing and be stuck where we are today.

> Considering that (estimated lifetime) deaths by all Nuclear (including Chernobyl and Fukushima, but excluding bombs) are less than one week of pollution deaths, it'd be an easy sell if we actually looked at numbers.

Than again, if Chernobyl or fukushima had experienced their worse-case scenarios, it's possible that nuclear would have caught up with pollution-related deaths instantaneously. Which illuminates the poor risk-assessment ability of the average person in regards to black swan events.

Worst operating failure, or worst engineerable outcome?

I mean if you took the nuclear fuel and fed it to people one lethal does at a time - yes. You could kill tens of millions.

But both reactors experienced almost the worst possible operating failure and this is how low the casualties were. Fukushima is leaking into the ocean and still not expected to cause a single radiation-based death.

Vastly more people have been (/will be) killed by runoff ponds of coal ash slurry rupturing and running into rivers than from radiation from power plants or spent fuel.

At 10k pollution deaths per week, for even just ten years, no. A nuclear reactor couldn't meet that (5M deaths) even if you left the switch in 'boom' mode and went home for the night.

You just took what you originally said, and said it again. Did you expect a different result?

If the worse-case engineering disaster happened in either case, millions would have died. If you want to dig into this point, great, happy to. If you want to repeat your original point ad-infinitum, pass.

> You just took what you originally said, and said it again

Only half of the last sentence, the conclusion, was repeated. But with space not being at a premium, I would happily restate something from up-thread because it can make it easier to read and reply to.

> If the worse-case engineering disaster ... millions would have died.

No, I don't think so. I think you'd need an engineered, as in intentional, disaster for that. Like terrorists.

And engineering disaster (improper planning) is what Fukushima had. That's very unlikely to be improper enough to kill an entire city because engineering mistakes tend to be planned for to some degree and mitigated by building redundant systems.

Very unlikely to cause a disaster, as in almost impossible even if you tried to form the same materials into a bomb.

Oh I see the problem: it doesn't seem like you know what you are talking about.

Both Chernobyl and Fukushima were critically close to absolute disaster.

Chernobyl was a potential kiloton-level steam explosion that would have jettisoned enormously radioactive material into the atmosphere and made country-sized swaths of land unusable for generations. They also exposed 600,000 people (the "liquidators") to direct contact with life-limits of radiation in the clean up. I also love the nukers going hand in hand with the oppressive soviet-era government in covering up the immense toll of Chernobyl, because it suits their argument.

In Fukushima's case, it was the fact they had decades worth of spent fuel rods that if they weren't able to keep them cool (which was a possibility in the first weeks after the disaster) would have ignited, once again releasing ungodly amounts of radiation. This practice of storing spent fuel rods onsite is also very common in the US, and it is a huge problem waiting to happen.

Great excerpt from suppressed Japanese report on Fukushima:

"A report delivered to then Prime Minister Kan Naoto on March 25 warned that if the situation at the plant spun completely out of control, authorities would have to issue mandatory or voluntary evacuation orders for all people living within 250 kilometers (155 miles) of the plant - a zone including greater Tokyo (population 35 million, the world's top city in terms of GDP) and the major cities of Sendai (pop. 1 million) and Fukushima (pop. 280,000)." source: https://apjjf.org/-Asia-Pacific-Journal-Feature/4706/article...

Gee, evacuate Tokyo. Oh well, at least we have our totally earth-friendly nuclear power!

> Oh I see the problem: it doesn't seem like you know what you are talking about.

Sorry, I couldn't afford your webinar.

> Chernobyl was a potential kiloton-level steam explosion

No, the building doesn't appear to have been structurally sound enough to have enabled a larger pressure explosion than it suffered.

> They also exposed 600,000 people (the "liquidators") to direct contact with life-limits of radiation in the clean up.

Well, closer to 250k were actually sent to the site. But do you think they all died? Or got cancer? Because they're being examined by international scientists working on the effects of radiation on people. If thousands of them died or went missing they'd know.

> I also love the nukers going hand in hand with the oppressive soviet-era government in covering up the immense toll of Chernobyl, because it suits their argument.

Let's say that you were right, that there were 600k (not 250k), and that they all died (as opposed to ~70), that's still only 60 weeks of normal pollution deaths. Even if you were right, it's not as big a number as you think it is. And that's in one of the more primitive countries that has nuclear, when it was going through it's financial and political death throws.

> In Fukushima's case, it was the fact they had decades worth of spent fuel rods that if they weren't able to keep them cool (which was a possibility in the first weeks after the disaster) would have ignited

No, it's that they had these spent fuel rods in the reactor building. It seemed easier because they didn't have to be moved as far, but proved to be a really bad idea once the reactor building was irradiated.

But it was never near the china-syndrome levels you describe. There was a plan to basically poke a hole in the wall with a really long crane, and then just fill the pools through the hole in the wall. They did equivalently dangerous work at the time and nobody get more than trivial exposure.

> This practice of storing spent fuel rods onsite is also very common in the US, and it is a huge problem waiting to happen.

Not so much. The Fukushima problem was storing them in the reactor building. If they were stored next to the plant, but not in it, there wouldn't have been a problem at all. Most plants store spent fuel outside the plant. (Often there's short-term storage next to the reactor waiting ~1y for much of the the fission byproducts to decay, then the fuel is moved to the nearby pool.)

> Great excerpt from suppressed Japanese report on Fukushima:

You know, most suppressed reports are really just wrong, and were not released because of that. Sadly, because conspiracy theories are fun.

The report was from 2011, when they were in the midst of it, and knew comparatively nothing. They now know that even the minimal evacuation zone wasn't needed and people even a few km away would have been safer staying at home.

> Gee, evacuate Tokyo.

No, that's ridiculous. That's at the level of an engineered disaster, where you take all the fuel and light it on fire and then let it continue to burn. That's not a realistic failure mode. Yes, a plant could catch fire (Chernobyl) but by the nature of a large containment rupturing explosion, you've usually got a place to pour fire retardant in. And we now know that meltdowns tend to create an elephant's foot type of barely-warm slurry by their nature. As they melt into the concrete and steel they naturally dilute and eventually don't have the heat to continue melting through the containment. Fuel geometries mean that an explosion would likely not remove even a large minority of the fuel from the reactor building, and fuel ejected from a reactor is unlikely to burn - whereas fuel in a critical configuration in a reactor, would. Such as in Windscale in the UK.

In so many ways, Fukushima was never close to a worse disaster. Further, many existing (by the time of the accident) safety designs would have already protected the plant. Spent fuel should have been outside, and the generators should have been nearby on the hill as opposed to barely above sea level in the basement. The electrical room (incoming power to run the backup pumps) should have been above ground, allowing the generators to be bypassed if they failed (or were flooded, like this time).

> No, the building doesn't appear to have been structurally sound enough to have enabled a larger pressure explosion than it suffered.

The steam explosion would have resulted if they were unable to prevent the core from melting through the floor to water below.

https://en.wikipedia.org/wiki/Chernobyl_disaster#Core_meltdo...

> Well, closer to 250k were actually sent to the site.

"According to the WHO, 240,000 recovery workers were called upon in 1986 and 1987 alone. Altogether, special certificates were issued for 600,000 people recognising them as liquidators." Perhaps you may just now be getting the sense that nuclear disasters don't just last 2 years? The clean up was long and dangerous, and you didn't get the certificate unless you were somehow exposed.

> ... No, that's ridiculous. That's at the level of an engineered disaster, where you take all the fuel and light it on fire and then let it continue to burn...

You have no clue what you are talking about. I literally gave you the source and it was from a report by the Japanese government. I'm sorry if you don't like facts that don't agree with your precious world view. Spent fuel rods remain radioactive and hot for years to decades, if they are not constantly and actively cooled, they shortly get hot enough to ignite their casings. Maybe you are just now learning that nuclear power is dangerous? Do you know how many thousands of spent fuel rods are sitting around in cooling pools onsite with reactors around the world? Better hope nobody has an OOPS.

I'm done.

> The steam explosion would have resulted if they were unable to prevent the core from melting through the floor to water below.

But it only creates a significant explosion if the building is intact, which it wasn't at that point. You were talking about a kiloton level blast. Had they not drained the basement it would have made the disaster worse, but nowhere near as much so as you think.

> Perhaps you may just now be getting the sense that nuclear disasters don't just last 2 years?

The part of it that would give liquidators a lethal does in a few minutes, no that didn't last two months, let alone two years. The first few weeks of running onto the roof and pushing a few shovel-loads of debris back over the edge into the reactor room before being replaced by the next guy were much different than the people calmly walking through the woods looking for bits of ejected core. Still dangerous, but orders of magnitude less.

> You have no clue what you are talking about. I literally gave you the source

Your source wasn't worth anything. It was nonsense they came up with before they knew the scope of the problem. Evacuate Tokyo. Lol! Not even close. Not even if all reactors had been impacted. It was redacted because it was wrong, not badly covered up so that people like you could find it as part of some strange conspiracy.

> Spent fuel rods remain radioactive and hot for years to decades

Many fission byproducts have a halflife and minutes to months. The first day/week/month/year of a spent fuel rod's afterlife are the most dangerous. If rods sit for a while (6m - 2y generally) they're safe enough to transport to a secondary pool.

> Maybe you are just now learning that nuclear power is dangerous?

No, I knew radiation was dangerous when I first read about the demon core accident. But nuclear power is still about 100,000 times safer than traditional power. You just refuse to value distributed deaths such as miners and pollution sufferers.

> But it only creates a significant explosion if the building is intact, which it wasn't at that point

Totally clueless. Unlike you, I'm not just making stuff up. If you drop gigawatts of thermal energy into a body of water, you don't need a containment vessel to create a large steam explosion.

Perhaps read the source I linked you? But we both know you won't do that, right. It's obvious at this point you only read or comprehend sources of information that confirm your worldview. How 2020.

> Perhaps read the source I linked you?

The redacted Japanese one, or the Wikipedia article?

The Wikipedia article doesn't contradict me. It says "serious explosion", but nothing about kilotons, and says "would eject more material" but nothing about a large area. That's a reasonable estimate.

> you don't need a containment vessel to create a large steam explosion.

You said a "kiloton level" explosion. That does require containment.

> If you drop gigawatts of thermal energy into a body of water

Before it melted entirely through, the concrete it was melting would be hot enough to boil the water on the other side. That steam would have been uncontained and would have vented out of the entrances to the basement, blowing doors open if needed. Based on how slowly the molten core was progressing downward this likely would have removed a fair bit of water before it actually melted through and began boiling the water rapidly.

And then, have you ever seen someone stick their hand (quickly) in liquid nitrogen or molten lead (done with a wet hand)? The Leidenfrost effect limits the contact with a layer of steam. You can't transfer those gigawatts straight into the water all at once. And while you're waiting, the steam is venting up through the new hole in the ceiling.

Without a sudden, contained, steam generation event the further core ejection would be limited if it happened at all.

> The steam explosion would have resulted if they were unable to prevent the core from melting through the floor to water below.

They drained the water and installed a heat exchanger. But this turned out to be unnecessary, since the core did not melt through the concrete flooring.

> Academic papers claiming feasibility decades from now is a vastly different thing than something actually being feasible. If it were, then we'd have all been using fusion power since the 1980s.

Of course the same holds true for MSRs. Regulatory hurdles mean any widespread deployment of nuclear is minimum 10 years away as well (the video shows the timeline for this reactor as 100MW in 2028, but I think that's optimistic, and it's just for the very first reactor.

I think we should pursue many avenues of reducing fossil-fuel reliance, primarily because I think its premature to say what solution(s) will win out.

Correct, we shouldn't use modular small reactors (or molten salt reactors for that matter). We should use the pressurized water reactors we actually know how to build. France generates over 70% of its electricity from them, and the US already generates 20% from PWRs. For every existing PWR we need to build 4, and that's enough to fulfill 100% of our electricity demand. Larger reactors are actually more efficient, too. The price per watt is 2-2.5x that of fossil fuels but they remain the only way to produce carbon-free energy around the clock besides geographically dependent solutions like geothermal and hydroelectric power.

MSRs may be useful eventually for remote power generation, but as far as bulk power generation the decades of experience building and operating PWRs is too compelling an advantage.

Belgium is closing its nuclear, and its carbon intensity gonna shoot through the roof...

> thereby avoiding risk of stranded costs for consumers and investors

This is what bankruptcy is for. If you’re investing in coal plants at this point, you should understand the risks.

Stranded consumer costs are solved by bankruptcy as well.

The local power utility goes bankrupt, their stock goes to zero, they don’t pay their bills, and the court allows them to continue operations and emerge from the other side in a solvent form.

Except if it’s PG&E. They should just fail and be forced to split up.

Australia is not targeting 100% renewables by 2032. Your own link says 'could be'.

Australia is currently at ~24% renewables. Note this is also because Australia has substantial amounts of hydro power that can be used in conjunction with solar.

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

On this front Australia may be a weird case. https://www.youtube.com/watch?v=92t8np88fEI

> Storage costs, despite being in freefall still are still in the hundreds of dollars per kilowatt hour range. And it's kind of moot since the total amount of storage produced globally is still a fraction of what is necessary to make renewables feasible as a primary source of power.

Funny that you also fail to mention that although storage levels are very low, we are still very far from reaching the market penetration of requiring storage. Transitioning a world's electric grid takes take, decades, plenty of time for storage to drop.

California's last non-fire brownouts were caused by too much solar in the generation mix without long term storage.

I see discussions about storage re renewables but I never see anyone mention the obvious solution. If you need power at night, just use high efficiency led lights to power your solar cells.

/jk

> storage cost is in freefall too

That's short-term storage. No seasonal storage technology is at a point where we could just point at a learning curve chart, draw a circle around some future intersection point and say "problem solved here".

Seasonal storage?

That's not a thing. You just scale your solar/wind installations to the part of the season with the least resource (solar and wind do not often have the same low point, either), which is economically feasible because it is cheaper than nuclear (and coal).

That dramatically changes cost calculation. Currently "cheaper than X" models don't account for such overcapacity factors. If there's no wind in summer and no insolation during winter you'll have to overbuild each by a factor of 5 or so and then build short-term storage on top of that. Conversely that means the bar to meet now is (renewables + storage) < fuel-based / 5.

That's a rather fat margin. And things would be a lot cheaper overall if we could shave that off with some long-term storage.

Running the numbers usually gives you numbers like 50% overbuild, but even if you're right, a 5x overbuild still is significantly cheaper than nuclear.

A 5x overbuild would give you massive amounts of "free" electricity. I'm sure the world would find something economically useful to do with it. Maybe you could use it to generate green hydrocarbons from atmospheric CO2, killing several birds with one stone.

It isn't quite that easy though because it's night for all 5x at once, for instance. So you need to have transmission capacity for the 4x you don't use locally, to send it elsewhere when it is sunny, and to import 1x at night from your sunlit neighbors.

> generate green hydrocarbons from atmospheric CO2, killing several birds with one stone.

This is great because it means we can use guilt-free hydrocarbons where they're important. Like rocketry and airplanes, making lubricants, plastic bags, etc.

> overbuild would give you massive amounts of "free" electricity. I'm sure the world would find something economically useful to do with it.

Generating proofs of work for a blockchain collectible card game? :D

> Maybe you could use it to generate green hydrocarbons from atmospheric CO2

Which would start to look a lot like long-term storage. But subsidized by negative energy prices during excess production. So rather than bleeding money while someone else makes profits any power company will prefer to build less overcapacity (which also avoids risking devalued assets) and run their own peak-shaving if they can. Which means this problem still has to be solved one way or another. Whether you call it long-term storage or excess energy use.

It may be dramatic, but so far it's still a lot less money than building several months worth of batteries.

> If there's no wind in summer and no insolation during winter you'll have to overbuild each by a factor of 5...

If nuclear power physics stopped working October to March, that would drastically effect nuclear power economic competitiveness...

Wait, what's this people are telling me, I can't just make stuff up?

You make up a completely BS example but then actually go through and try to come out with actual numbers. Right.

Windless days and cloud cover are phenomena that actually exist and are observed. The behavior of beta particles suddenly changing is not.

Yes, 5x variability in wind production has actually been observed: https://en.wikipedia.org/wiki/File:Erie_Shores_Wind_Farm_out... https://en.wikipedia.org/wiki/File:Windpowerprediction.png

The statement was no X in Summer, no Y in winter. It was not talking about a daily or even weekly phenomena but seasonal one.

There is no summer which have had no winds, no winters that have had no insolation or vice versa. Instead of making up numbers, you can use a site like this: https://www.solar-electric.com/learning-center/solar-insolat....

You'll find that by comparing seasonal best case to seasonal worst case it is something like, on average, 50% difference. It gets worse the closer you to get to the pole obviously.

Furthermore, surplus production does not go into dev/null. Excess resources create markets, and there will be consumers that take advantage of cheaper surplus power (smelting, heavy industrial, desalination, hydrogen production, and whatever else anybody cooks up).

> There is no summer which have had no winds, no winters that have had no insolation or vice versa.

The part of "no production" were not meant to be taken literally. If you want a more precise statement then let me put it this way:

For PV in central europe even an overcapacity factor of 5 would be insufficient to cover the difference between summer and winter. Germany's PV plants produced 7.3TWh during June 2019 and 0.58TWh during december 2018.

Wind does look a bit better as far as seasonal differences go (about 4-5x) but it suffers from more short-term variability, so you might need less seasonal storage for it but it would require more medium-term (multi-day or -week) storage compared to solar which is a bit less variable during its peak months compared to wind's peak months.

Building out the grid will help out a lot. Put those solar panels in Portugal and Spain and the difference between winter and summer is much less. I ran some numbers recently for Portugal's grid and was surprised to find out that with the current seasonality of solar, wind and hydro we have on the grid, we could scale up solar and wind to have 100% renewables with very little overcapacity and we could keep going and produce twice our current needs while exporting about the same amount of energy every month of the year. Solar and wind's seasonality match up quite well and hydro gives great flexibility.

24 hours worth of storage and 2x the wind turbines would smooth out the lack of supply in the graph you cited. A 5x seasonal variation would be more serious. I guess that exists at the poles with solar, but that’s getting into a small total percentage of global energy demand (and they could probably still use wind, unless snow prevented it).

24 hours worth of storage worldwide is 60 TWh currently. Once Asia and Africa become more developed this will likely become closer to 100 TWh. By comparison annual global battery production is just under 0.3 TWh - and only a small fraction of this goes to grid storage, the bulk goes to electronics and electric vehicles.

This leaves experimental solutions like the Sabatier process, Hydrogen storage, or more exotic things like lifting concrete cylinders with pulleys.

There is this concept of "Gravity Storage" [1] which could be promising, if some testing were to be done on it.

Basically you cut a large cylinder out of the earth and lift it by pumping water below it. When you then need the energy, you release the water with the help of the weight of the cylinder and use it to generate electricity.

It sounds a bit crazy, but it could be worth testing that approach, since it can also be used in a flat area like a desert.

In any case, the company filed for insolvency this year [2].

There is a podcast episode [3] from "omega tau podcast" dedicated to it, which is worth listening to.

[1]: https://heindl-energy.com/

[2]: https://heindl-energy.com/about-us/

[3]: https://omegataupodcast.net/299-gravity-storage/

The energy density of gravity storage is abysmal. How abysmal? A mobile phone battery can lift a 1-ton weight 10 meters.

That is missing the point of my comment. I didn't say that no experimental technology exists. I said that no technology exists where we can point to a chart from which we can conclude that the technology will be ready and economical in a certain number of years if trends continue.

Chemical storage (as methane or whatever) would work fine and the operational side would be more or less carbon neutral. The cost is high compared to burning fossil fuels, but we could do it as a society (have an excess of solar to meet household winter electrical needs and synthesize methane in the summer to use as household heat fuel in the winter).

Just pulling numbers out of the darkness, the upfront cost here in a cold region would be ~¼ to ½ the cost of a house. High, but also clearly workable.

Iron-based storage seems promising...

https://news.ycombinator.com/item?id=24996153

Hydroelectric has been a viable form of seasonal storage for a while. Unfortunately, it stores energy when it’s rainy, and releases it when it’s sunny.

And we’re still doing storage wrong. My A/C could have a reservoir of refrigerant that is compressed overnight. Same for my fridge/freezer. Or my fridge could make ice that’s held until peak hours. My deep-freezer could have an ultra-chill zone that runs at night. My dryer could run in slow-mode if I turn it on at a dumb time. My water heater (even a gas one has a 250w powered vent) could ultra-heat during off-peak. My dishwasher could auto-delay until 3am......

We don’t even need “smart” 2-way comm appliances. Just a weather forecast should work well enough to predict.

>My A/C could have a reservoir of refrigerant that is compressed overnight.

Not unless you want to just vent all of the refrigerant during operation. You need to keep the suction side under low pressure otherwise it'd just stop boiling the refrigerant.

>My deep-freezer could have an ultra-chill zone that runs at night.

That'd be making it much less efficient so even if you can get away with some load shifting here you'd be increasing the load substantially in order to do so. Also this would cause large repeated temperature swings for everything inside, might not be too big of an issue once it's already frozen but still, undesireable.

>My dryer could run in slow-mode if I turn it on at a dumb time.

Your dryer could be replaced by a much more efficient design such as a heat pump dryer or a mechanical steam compression dryer.

>My water heater (even a gas one has a 250w powered vent) could ultra-heat during off-peak.

Safety devices make this a complete non-starter. A mixing device to lower the output water temperature can fail and probably eventually would fail stuck all the way hot making this a substantial burn hazard. Even ignoring this, all water heaters have a temperature and pressure relief valve and increasing the water temperature to e.g. 200 degrees instead of 140 substantially reduces the safety margin you have between normal operating conditions and catastrophic failure of the tank (a sizeable explosion). Also you're not really gaining a lot here, you could just use a standard water heater timer to turn it off during peak hours and rely on storage capacity. Increasing the setpoint from 140 to 210 assuming ambient cold water temperature of 70 degrees only doubles your hot water equivalent capacity. I suspect it would be cheaper to increase the tank size and not have to deal with the more challenging operating conditions. Also, again, a much better solution is just widespread adoption of heat pump water heaters. For most homes you don't need the higher output of a resistive water heater and even if you did every heat pump water heater I've seen still comes with resistive heating as well if it can't keep up with demand. The decrease in energy bills pays for itself over the lifespan of the appliance.

Personally I've always wanted to see a practical combined heating and refrigeration system for a home that could tie in a fridge, HVAC, hot water heater, etc via CO2 refrigerant.

> I've always wanted to see a practical combined heating and refrigeration system for a home that could tie in a fridge, HVAC, hot water heater, etc via CO2 refrigerant.

This has been done commercially for decades, but my guess is that the potential savings at home residential scale are not enough to offset the cost and additional complexity.

Fridge/freezer combos are already a compromise design that sacrifice efficiency for floor space. Chest freezers that open from the top are far more efficient (the cold air doesn't all pour out when the door is opened.)

...and don’t get me started on freezer-below units. Who wants a system where relatively warm fridge air sits right above the cold freezer?

My water heater, dishwasher, washer and dryer are already timed to work during off-peak - what are you waiting for ? (I'll have to check about fridge ice, good idea!)

Maybe the new ones have it, but most of the ones I’ve used (manufactured over last 5-15 years) don’t have it, or have a single delay setting and that’s it. This is in sorta-cheap electricity Canada.

Well, I guess I'm cheating - only my water heater gets an automatic "off peak" signal, coming via the electric power grid. For all the others, since I don't run them every day, I just have my watch reminding me when it's "off-peak time" and/or delay them to night off-peak...

FWIW, my gas water heater has a chimney, not a powered vent.

Probably bigger exhaust pipe (ie: not 3?” PVC) and straight up so it always acts like a solar chimney or Venturi pump.

I’m unsure which is more efficient in the end.

Sorry to break it to you https://twitter.com/wstrzelecki/status/1336754768002347010?s...

Storage costs are in freefall because the bulk of the car market about to transition to electric and it's creating economies of scale and spurring a ton of R&D which is picking all the low-hanging fruit in battery cost improvements.

It's difficult to predict how long that will continue before the easy gains run out. Maybe the existing curve will continue for another 30 years. Maybe it will continue for another 30 days.

If it continues for 30 years, we're fine. If it peters out before solar+batteries are cheap enough, we still need nuclear and we're that far behind where we would be if we started building it now.

Worst case if we build it now is that we have some nuclear plants that cost somewhat more to generate power than future technologies will (but still in line with existing prices). Worst case if we don't is we get more climate change. Which one is more expensive?

> Storage costs are in freefall because the bulk of the car market about to transition to electric and it's creating economies of scale and spurring a ton of R&D which is picking all the low-hanging fruit in battery cost improvements.

That's not true. Utility scale storage is a huge area of interest, has had many advancements in recent past and many of technology paths have absolutely no relation to electric tech or economies of scale.

It is true. Making batteries for electric cars is a large fraction of the storage R&D, and the existence of non-vehicle storage technology development doesn't really change the equation anyway.

The question is whether storage gets cheap enough before the cost stops falling, and the answer is we don't know and we need to be prepared in case it doesn't.

Sticking your fingers in your ears and saying, "Ah ha!", does not an argument make.

I spent 6 years in the solar industry, working at both a start up and a fully vertically integrated behemoth that manufactured panels and built plants and while I'm no longer in the industry today, I'm confident I am up-to-date on utility-scale storage progress and it is not summed up by, "electric car batteries!"

You're arguing with a straw man. I never claimed storage technologies other than lithium batteries didn't exist. Electric cars continue to be a central example of the relatively recent increase in research into storage technologies.

And you still can't extrapolate indefinitely from an exponential curve. We don't know where the floor will be, or whether it will be low enough.

... which is a very good idea for both cost and safety reasons.

It's sort of like how SpaceX is blowing up a lot of flying beer cans before packing one with people and expensive equipment.

Why would anybody pay for that?

Because it's a pretty good idea to know if the stuff that's responsible for containing the radioactive parts can do the job?

They are selling these to customers. GPs question is what customers would do with them.

I presume customers are manufacturers of potential reactor parts that want to see that they can handle the salt, temperatures etc.

edit: from the datasheet[1]:

The portable loop are sutable rapid prototype validation, long term testing of mean time between failure, salt compatibility testing, and many types of experiments that require flowing molten salts.

Components such as gaskets, flanges, filters, valves, pumps, pressure sensors, flow meters, and heat exchangers, etc. can be tested inside the furnace with flowing molten salt.

[1]: https://www.copenhagenatomics.com/products.php

Low corrosion materials and parts designs might still be worth it in other non-nuclear industrial processes?

It is better to make sure that the reactor won't corrode through just from the molten salts prior to testing it with radioactive molten salt. This is currently not clear.

This is a false title. Copenhagen Atomics sell a portable molten salt test loop, which universities, etc. use for research in molten salt technology. Copenhagen Atomics also plan to build a 1 MW test reactor, to demonstrate the technology. The two are not the same thing and not the same price :-)

I'm wondering what kind of safety these would have. A 100 MW reactor in a single shipping container is crazy efficient - just curious what infrastructure around that would have to be built

You mean crazy dangerous. At that power density, everything has to work for this thing to not meltdown.

So actually that’s the whole design of these things. You have to work to keep them running. In case of a meltdown, the fuel is passively drained by a plug.

In case anyone else was wondering how having the molten fuel pour out of the reactor is safe - it is designed to pour into a container with criticality safe geometry to stop fission:

"in an emergency situation [the fuel] can be quickly drained out of the reactor into a passively cooled dump tank. MSRs designs have a freeze plug at the bottom of the core—a plug of salt, cooled by a fan to keep it at a temperature below the freezing point of the salt. If temperature rises beyond a critical point, the plug melts, and the liquid fuel in the core is immediately evacuated, pouring into a sub-critical geometry in a catch basin. This formidable safety tactic is only possible if the fuel is a liquid." [1]

[1] https://www.sciencedirect.com/science/article/pii/S168785071...

> This formidable safety tactic is only possible if the fuel is a liquid." [1]

Isn't something similar possible with pebble reactors, at least in principle?

Possible, and implemented in recent reactors - for the "corium". Though in that case it's for the extreme situations, since after that the reactor is completely done for.

I would love to see what a sub-critical geometry looks like. I also wonder what kind of math and engineering they did to come up with the shape they ended up with.

http://thorconpower.com/wp-content/uploads/2019/03/ColdWallL...

This one is just a bunch of separate tanks spaced as far away from each other as possible.

I've also seen a "Bed of nails" design where the liquid salt would flow over a bunch of moderating spikes, seep down between them and freeze.

In some contexts, a subcritical geometry is simply a plastic jug that's too small to hold a critical mass. Obviously they're not using plastic jugs for this, but the principle of the thing is pretty straight forward. They could create a wide 'dish' under the reactor which, if the liquid fuel were drained into, would spread the fuel out into a shallow puddle using the self-leveling property of fluids.

> I also wonder what kind of math and engineering they did to come up with the shape they ended up with.

I assume this is why some Finite Element Analysis packages come with warnings along the lines of "You must not use this to help Kim Jong-Un do you know what"

Feynman wrote of this when he was working at Los Alamos, i.e. the labourers weren't informed as to what they were really working with, so they could come very close to criticality accidents.

A pyramid may work with a wide flat basin at edge, especially if core material is moderating itself (vs just separating).

a pancake ?

So instead of melting down by accident it melts down deliberately, controlled by a fan?

Somehow I'm not as reassured as I might be.

Well, no. A meltdown is when the stuff escapes containment and then continues undergoing fission, heating up and melting out of containment and into groundwater/the environment.

The drain tanks are shaped specifically so if the (liquid) fuel flows in, it will stop reacting. And presumably the whole apparatus (drain tanks included) is inside of a biological shield.

So a "meltdown" here just means a big hunk of solid nuclear salt inside the bio-shield. I think the idea being that you could just bury the whole thing in case of failure.

IIRC draining the fuel salt into the drain tanks was standard operating procedure for one of the early MSR experimental reactors.

Next morning when they came in to continue experiments, started the (electrical?) heaters to liquify the salt and pump it back into the reactor core.

Wouldn't surprise me if the modern designs are similar.

This would not be melting down. Melting down is melting out of the containment device, which this is not doing. True it is melting INTO a secondary containment device but unless it continues to melt through that it would not be a 'melt down'

Also, there is no pressure build up, which is what caused the big explosion in Fukushima. All the coolant starts boiling, turning into gas, and well the rest was in the news

Just for clarification, the big explosion at Fukushima was a hydrogen explosion. At high temperatures, fuel cladding breaks water into hydrogen and oxygen. Hydrogen collected at the highest point in the structure and later exploded.

My understanding is that these reactors are designed to have a lot of passive safety features (e.g. if all operators walk away the reactor will cool itself and go sub-critical), so quite the opposite of what you are claiming.

Those safety systems don’t exist in a shipping container sized nuclear reactor. One method that I think you’re talking about is when the temperature of the molten salts goes beyond a certain safety threshold then a heat sensitive plug is disintegrated and the Milton salts are drained into a safe underground reservoir for them to cool. (This is my recollection from that why thorium is the future video that went viral years ago) Can’t do that in a shipping container.

I was thinking of Copenhagen Atomics' Waste Burner design where they describe their passive walk-away safety features as "Prime minister safety" [1].

> The CA Waste Burner has a set of systems governed by the laws of physics that cannot be overruled by humans, and which will cause the reactor to shut down safely if something goes wrong...This means that operators are not required to watch for alarms and act in accordance. The CA Waste Burner must be able to automatically shut down before any human can react to an alarm and choose what to do. If human action were ever required for operation, other than during startup procedures, then we would consider it a design failure...

[1] https://doi.org/10.1016/B978-0-08-101126-3.00023-3

> The CA Waste Burner has a set of systems governed by the laws of physics that cannot be overruled by humans, and which will cause the reactor to shut down safely if something goes wrong.

This is really good, but humans have an amazing knack for messing stuff up and I really hope corners aren’t cut building and maintaining it.

What comes to mind is the situation in Japan where workers inadvertently had some material go critical, and while this was being investigated it was found that they were carrying waste uranium and nitric acid around by hand in buckets.

https://www.newscientist.com/article/dn20263-japans-record-o...

Reactor shipped with "some assembly required."

Isn't molten salt already molten?

The shipping container only has the reactor, it does not produce the actual power. You would still need turbines etc for that externally.

Love this, but why are the timescales so long?

regulation

Not just. Capital, technology, expertise, skilled labor force. All are scarce currently.

Really the only guys/gals are either doing the good old pressurized/boiling water reactors, teaching at universities, or military. There's not enough molten salt expert, there's no supply chain for parts, materials, systems, services.

And there's not enough incentive. Maybe with a steep carbon tax.

Uber, Airbnb etc. circumvent regulation ;)

Please do not invent Uber for nuclear.

Move fast and irradiate things.

To be fair, it was basically the history of early military nuclear technology. US, France and USSR irradiated many of their own people to develop their first nuclear bombs. Civil nuclear heavily benefited from those advances. Still, I rather not be irradiated to make science go faster.

If you think about it nuclear does force the vast majority onto someone else so maybe it already is...

Mushroom Cloud.

IaaS for all thing nuclear.

Apparently unrelated to Copenhagen Suborbitals. As much as I love Copenhagen Suborbitals, I'd rather not want to see them growing an atomics subdivision..

That is the future merged company :-)

Are any other Molten Salt Reactor builders doing anything similar?

If SpaceX had taught me anything then it is that rapid iterations on prototypes is the way to go.

A prototyping failure on a fission reactor is a little different than a rocket exploding on the launchpad...

SpaceX blowing up a Crew Dragon capsule wouldn't be good either, but can you do the fast development testing and expect some failures, and don't go near nuclear material until much later in the process.

Even ignoring the radiation, how do you test that it keeps working with a 100 MW heat source inside it without putting nuclear material in?

Edit: where did I get the idea it’s 100MW from? Title talks of 1MW. That makes it a lot easier.

If 1MW is the actual design limit, it should be possible to test the loop with a mock heat source. At this scale, you could pay for grid power ($40-60/hr).

100MW would be a lot trickier to test due to infrastructure limitations, but you could probably figure something out with natural gas or propane burners.

By putting enough resistors inside, and pumping 100 MW of electricity in? If you're a utility trying this out, you can probably handle that (for some hours, maybe not for weeks).

Are there any resistors that would not melt under this situation?

Good question. There are two issues, the power and the temperature. The power is easy(ish) - just put enough resistors in there, and you're good. (If you physically can put enough resistors in that space, which... I don't know.)

But you also want to run it at reactor temperatures. I don't know what that is, but finding resistors that won't melt may be anywhere from difficult to impossible.

These prototypes don’t contain radioactive material though.

Unfortunately there are only two ways get a nuclear reactor working, one is for research, the other full on production. In the US regulatory system there is no in-between.

That is why all the reactor companies go for a fully functional production design with the first try. Without such a plan and reactor built, you do not get access to fissile material. Since you have to build many of them to ever have a hope of making money fast iteration is gone be difficult.

In general they all want to use the same basic design with different fuel and different operations to create a different type of reactor. Uranium fast burners are the easiest, thorium breeders are much further away.

For Molten Salt Reactors, the most advanced in development is probably IMSR by Terrestrial Energy, after that SSR by Moltex Energy are both currently in Canadian regulatory process.

Flibe energy is trying in the US but that is longer term, there is not even a regulatory process in the US yet. Flibe is by Kirk Sorensen the guy who basically restarted Thorium hype.

If the US government was serious about wanting to let nuclear power development happen in the US, they should set up a location where companies could work with live nuclear material while developing reactors. Workers could be required to have some type of security clearance and each company could have its own building(s) to avoid "mistakes" at one company from effecting other companies people and worksites. OSHA rules could be relaxed to allow quicker development, as everyone working there will be well informed of the radiation risks. The former nuclear test site in Nevada would seem to be a great location for this.

The list of things the government could do, even without a huge investment, to make nuclear happen is incredibly long. Sadly non of it is gone happen.

In my opinion, humanity should have long been living in the nuclear age and its kind of crazy that we are not.

If you can fund them.

There are many!

I hope this makes more waves.

Anything atomic for <100k deserve attention.

...but molten salt for <100k.

WOW

Nuclear is obsolete now that there are working prototypes producing 250KW for 100 hours+ from the reaction of hydrogen to hydrino (dark matter):

https://brilliantlightpower.com/the-suncell-at-the-100-hour-...

public demonstrations coming soon: https://brilliantlightpower.com/station-6a-december-10-2020/

"dark matter" ??

In case you hadn't figured it out already, it's a scam. They claim to reduce hydrogen to an energy state below the ground state using some kind of quantum voodoo.

The theory is all classical ie electric and magnetic fields and while there are quantum states in the sense of electron orbitals including previously unrecognised ones below the traditional ground state, there is no quantum math ie wavefunctions. No entanglement, no dead and live cats etc. Electron orbit is modeled as an infinitessemally thin fluid shell with charge elements spinning around the nucleus along all great circle orbits. However, while spinning, the orbital does not change - it's like a standing wave, and thus it does not radiate.

https://brilliantlightpower.com/hydrino-dark-matter/

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