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Smaller reactors bring nuclear power closer to fulfilling its promise

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Re: Smaller reactors bring nuclear power closer to fulfilling its promise

#111

Post by Animats »

How are the fusion startups coming along? There are at least 21 of them.[1]

The top 3, by funding. These all have more than a billion dollars.

Commonwealth Fusion Systems. The MIT people. This is a tokamak with better magnets. The magnet insight is that if you put a superconductor and a regular conductor in parallel, all the current flows through the superconductor. So you can plate a superconducting material on stainless steel tape, using stainless steel as an insulator. Winding a magnet out of stainless steel tape works fine. They demoed that back in 2021. But no fusion yet. Well funded, big operation, around 1000 people.

Helion Energy. This is a strange magneto-inertial fusion system. It's vaguely like a free-piston internal combustion engine generator, except that the piston is a plasma. After seven rounds of increasingly large prototypes, they can get D-T fusion, but it's not self-sustaining, nor do they get power out. Prototypes have thus far underperformed claims. Around 500 people.

TAE. Recently merged with Trump Media. Really.

There are quite a few others. Many are working on some kind of pulsed fusion, like the Livermore National Ignition Facility. This is known to create fusion, but is hard to turn into a useful power source. They can get to a non-useful fusion demo by pumping a lot of energy into a small space, so it looks like progress.

On the continuous fusion front, several startups are trying to revive 1950s Stellarator technology. For a few years back then, fusion energy looked close.

Anyone have expertise in this area? Are any of these going to work? Or is the product the stock?

[1] https://www.energystartups.org/top/fusion-energy/USA/

Re: Smaller reactors bring nuclear power closer to fulfilling its promise

#112

Post by fpoling »

inglor_cz wrote: post #50
soco wrote: post #3

With solar and batteries getting cheaper and cheaper, is this still a topic? Or at least for the time being until that "cheaper" gets cheaper enough?

Scaling is a problem. How many batteries do you need to power, say, entire Scandinavia during winter? That would be a lot of lithium, btw. "Dunkelflaute" periods when it is dark and no wind to run the wind turbines are common in northern winters, IIRC the longest one a few years ago was 12 days long. Which means that in order to have a reasonable buffer against it, you would need enough batteries to supply the entire…

Sodium batteries are cheaper for storage and does not require any rate/expensive minerals, just scaling up production. Then in Scandinavia the main problem in winter is heating and using heated water as a battery is already a thing. Then producing amonia or even carbon fuel from atmosphere for energy-dense storage will be viable option in 10-20 years. And of cause Norway and Sweden can have massive hydro for energy storage.

Re: Smaller reactors bring nuclear power closer to fulfilling its promise

#113

Post by chickenbig »

mayama wrote: post #41
hwillis wrote: post #14

And a contrasting article from IEEE: https://spectrum.ieee.org/the-forgotten-history-of-small-nuc... > Samuel B. Morris, the general manager and chief engineer of Los Angeles’s Department of Water and Power, traveled all the way to Geneva in 1955 to attend the first International Conference on the Peaceful Uses of Atomic Energy. There, he made a case for small reactors, arguing that because the “number of small units…

> Even if its cheaper to build small reactor vessels, MANY of the other costs become more expensive in larger numbers. There is no way SMR could beat solar+battery power cost even now. With sodium and other batteries projected to reduce storage cost, it is even more unlikely that SMR could be price competitive in future grids. SMR is the only way that dying western nuclear industry could attempt to deal with ballooni…

> There is no way SMR could beat solar+battery power cost even now.

Not a particular fan of this paper, but it does illustrate a point ... https://ieeexplore.ieee.org/document/8867359 showed that for the UK to go 100% solar it would need an energy capacity of 1/3 of the total grid energy demand over the year. Figure 6 A shows the big trend of 6 1/2 months of discharge and 5 1/2 months of charge (i.e. cycle perhaps once a year). Seasonal variations do matter.

Re: Smaller reactors bring nuclear power closer to fulfilling its promise

#114

Post by fpoling »

Animats wrote: post #111

How are the fusion startups coming along? There are at least 21 of them.[1] The top 3, by funding. These all have more than a billion dollars. Commonwealth Fusion Systems. The MIT people. This is a tokamak with better magnets. The magnet insight is that if you put a superconductor and a regular conductor in parallel, all the current flows through the superconductor. So you can plate a superconducting material on stai…

Helion most likely would not work. Even their own optimistic modeling gives very thin margins and even they completely ignore radiation damage to equipment.

Commonwealth and other tokamak designs are too optimistic as well. We do not know how instability in plasma will behave in production volumes.

Stellarator-based designs at least do not have big ifs, but they are way further and even they assume that radiation damage from neutrons will be manageable.

And all of this is ignoring costs. Outside of niche applications it is very hard to sea how fusion even if it works can compete with solar plus storage.

Re: Smaller reactors bring nuclear power closer to fulfilling its promise

#115

Post by chickenbig »

fpoling wrote: post #108
fasterik wrote: post #38

Earlier quoted context omitted.

The problem with 100% solar+batteries is that you need to massively overbuild for the system to meet demand. It's far more cost-effective to have some portion of generation come from a firm, weather-independent source. The main options are fossil fuels, hydro, geothermal, and nuclear. Since fossil fuels emit carbon and hydro and geothermal are geographically limited, nuclear is the best option in a lot of places.

If solar becomes 2 times cheaper, it will be economical to capture nitrogen from atmosphere and produce ammonia and use that for long-term energy storage and fuel. And with that one does not need massive solar overbuild. This does not require any magic technology, just scaling up what is available today is enough and will definitely happen within the next 20 years, before small nuclear will have any effect.

> If solar becomes 2 times cheaper

It would be good to see a techno-economic analysis of this. For instance, taken to the limit, if solar were free what would be the CAPEX and OPEX to produce the ammonia? In addition, the plant to consume the ammonia to produce electricity would not be free.

Re: Smaller reactors bring nuclear power closer to fulfilling its promise

#116

Post by idiotsecant »

bryanlarsen wrote: post #80
DennisP wrote: post #74

Earlier quoted context omitted.

But coal is still 49%. The whole point of nuclear in a carbon-free, mostly-renewable grid is to avoid needing enormous amounts of storage and overproduction. That's a need that doesn't come up when you're still half fossil. If you want to decarbonize as fast as possible, it makes sense to focus on rolling out wind/solar/battery as fast as possible for now, but keep developing nuclear technology to cover the last bit…

The most cost efficient new-build grid is 90-98% solar/wind/battery depending on your locales insolation & wind coverage. (Source Ember Energy) The remaining 2-10% is nat gas, if you have a piped source, or coal if you don't. But 98% renewable doesn't mean you can hit 100% by adding 2% more of something else, it means your something else has to supply ~100% of the power 2% of the time. If China is aiming for that cos…

Solar battery is not by any stretch of any possible definition the cheapest generation to deploy. Not even close. We do a disservice to the entire conversation saying easily falsifiable things like that. At 90% penetration solar + battery has a LFSCOE somewhere around $800/mwh depending on the study. Natural gas is something like 30-60. Solar panels are cheap. Building the required transmission and storage to service those panels is far more expensive than the panels themselves.

Increased renewable generation is an important goal, but we need to let the facts guide the path, not the other way around.

Re: Smaller reactors bring nuclear power closer to fulfilling its promise

#117

Post by Procrastes »

will5421 wrote: post #110
stymaar wrote: post #106

Earlier quoted context omitted.

> there is new geothermal power companies getting funding and are transitioning from pilot projects to production. If geothermal works economically (outside of volcanic zones where it already does) then it's game over for any other power source except existing dams though because it solves all problems at once. That'd be a great thing for humanity but I don't think it's worth stopping pursuing alternatives already, b…

Won’t geothermal cool the Earth’s core?

I'm not a geologist, but for comparison, the Siberian Traps[1] erupted for 2 million years, and there have been other large events on that scale. Any heat we release will be insignificant in comparison.

1. https://en.wikipedia.org/wiki/Siberian_Traps

Re: Smaller reactors bring nuclear power closer to fulfilling its promise

#118

Post by Procrastes »

elcritch wrote: post #79
mayama wrote: post #41

Earlier quoted context omitted.

> Even if its cheaper to build small reactor vessels, MANY of the other costs become more expensive in larger numbers. There is no way SMR could beat solar+battery power cost even now. With sodium and other batteries projected to reduce storage cost, it is even more unlikely that SMR could be price competitive in future grids. SMR is the only way that dying western nuclear industry could attempt to deal with ballooni…

If solar+battery were cheaper wouldn't the new AI data centers be opting to pay to build that rather than nuclear or LPG options?

Some of the data centers in Texas are at least partly being built to turn surplus natural gas into cash.[1][2]

1. https://energynow.com/2026/03/us-natgas-prices-at-waha-hub-i...

2. https://www.rbccm.com/en/insights/2026/05/natural-gas-powers...

Re: Smaller reactors bring nuclear power closer to fulfilling its promise

#119

Post by hwillis »

gwbas1c wrote: post #101
hwillis wrote: post #14

And a contrasting article from IEEE: https://spectrum.ieee.org/the-forgotten-history-of-small-nuc... > Samuel B. Morris, the general manager and chief engineer of Los Angeles’s Department of Water and Power, traveled all the way to Geneva in 1955 to attend the first International Conference on the Peaceful Uses of Atomic Energy. There, he made a case for small reactors, arguing that because the “number of small units…

There's a political issue. Just look at how hard it's been to protest all the new gas plants that came up over the last ~20 years. The reason is that we built many small gas plants, instead of a handful of large ones. It divided up the protesters to the point where they couldn't work together. When we built less, but larger, nuclear power plants, they're easier to protest. If we can make SMRs economical, it makes it…

> Just look at how hard it's been to protest all the new gas plants that came up over the last ~20 years.

People have been talking about SMRs being the economic future for over 70 years. It has not happened because it not true.

Re: Smaller reactors bring nuclear power closer to fulfilling its promise

#120

Post by marshray »

DennisP wrote: post #74
bryanlarsen wrote: post #51

Earlier quoted context omitted.

To a first approximation, China does not build nuclear power. Nuclear's share of power production in China is 4% and dropping. It seems to me that the main reason China keeps building a relatively tiny amount of nuclear is strategic. Reasons like ensuring they never forget how and ensuring they always have buildable designs so that if something changed they could ramp up the program. And probably even more likely: nu…

But coal is still 49%. The whole point of nuclear in a carbon-free, mostly-renewable grid is to avoid needing enormous amounts of storage and overproduction. That's a need that doesn't come up when you're still half fossil. If you want to decarbonize as fast as possible, it makes sense to focus on rolling out wind/solar/battery as fast as possible for now, but keep developing nuclear technology to cover the last bit…

Enormous amounts of storage is awesome and overproduction is a good thing when its marginal cost is ~zero.
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