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Smaller reactors bring nuclear power closer to fulfilling its promise

nature.com

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

#61

Post by pfdietz »

roryirvine wrote: post #54
samizdis wrote: post #30

Hmmmnnnn. I remember getting excited reading a Wired article "Let a thousand reactors bloom" [0] - but that was back in 2004. I'm still waiting for a "pizza-safe" pebble-bed reactor. [0] https://www.wired.com/2004/09/china-5/

This Nature article dubs TRISO fuel as "accident-tolerant", which is just as well given the lamentable history of it in actual use. https://en.wikipedia.org/wiki/AVR_reactor for instance, which suffered so many accidents that it was known as the "Shipwreck". It ended up with TRISO pebbles getting stuck in the reactor vessel, the primary circuit being hopelessly contaminated with fission products, and is now impossibl…

TRISO is also more expensive, both in fabrication and disposal. It looks to me like another case of nuclear mis-optimizing for the wrong metric (safety vs. cost).

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

#62

Post by pfdietz »

RivieraKid wrote: post #32
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?

Solar + battery is very land inefficient, that's basically the main argument. Edit: Per ChatGPT's calculation, nuclear is significantly cheaper than solar + battery in my country (Czech Republic) if we're talking about adding new reactors to existing power plants.

Land is cheap. Even in Europe, the cost of land onto which renewables are put is small compared to the cost of the renewable energy equipment itself. Here in the US, it's common for the land to be just a few percent of the project cost.

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

#63

Post by pfdietz »

jauntywundrkind wrote: post #7
petcat wrote: post #4

Earlier quoted context omitted.

> In March 2025, the US Department of Energy (DoE) announced US $900 million in grants to support the deployment of SMRs. One year later, the European Commission said it would invest up to €200 million (US $228 million) in the construction of SMRs. Yes, it does seem to still be a topic.

And the US is spending vastly more to make sure renewables and solar don't get built. https://www.washingtonpost.com/business/2026/08/27/how-wind-...

> making sure

If this is the goal, they're failing spectacularly.

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

#64

Post by pfdietz »

bryanlarsen wrote: post #60
inglor_cz wrote: post #50

Earlier quoted context omitted.

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…

That 12 day event was a regional event in Germany, there was still lots of wind in the North Sea. And sun & wind didn't drop to 0, it dropped below 10%. Dunkelflaute's are a German phenomenon: the standard pattern in most of the world is that the high pressure systems that suppress winds are generally sunny. And the high elevation areas in Germany are sunny during a dunkelflaute. IOW, batteries aren't the only answer…

Hydrogen is one possibility for a 100% grid to cover Dunkelflauten and seasonal leveling (the former for wind, the latter for solar). To see the effects on overall cost per MWh, explore at https://model.energy/

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

#65

Post by pfdietz »

wing-_-nuts wrote: post #53
jauntywundrkind wrote: post #6

They're all ridiculously fuel inefficient and we're going to have to figure out how to dispose of thousands or tens of thousands of these reactors. Aside from that one that starts pre buried, where the plan is to just leave a spent nuclear reactor buried in a hole. A cost that will almost certainly be externalized to the taxpayers. The promise here is the rich fleecing the average citizen. Getting downvoted wicked ha…

'Fuel efficiency' is not the bottle neck to getting more clean energy on the grid, scale is. Waste? grind it up, vitrify it, bury it in an abandoned coal mine or something. People get more radioactivity from a coal power plant than they will ever get from properly handled nuclear waste.

It sure is. If the world were nuclear powered (all energy, not just grid) with burner reactors, estimates of uranium resources (not reserves) at up to 3x the current price would last about five years.

A fully nuclear world needs to use nuclear fuel efficiently, which means breeder reactors.

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

#66

Post by bb88 »

hn_submit wrote: post #5

Although generally safe these reactors aren't totally safe. I'm concerned lax physical security will allow miscreants to blow them up and spread nuclear materials over a wide area. The ensuing panic would totally destroy any goodwill nuclear power has gained over the last 20 years or so. I'm also concerned these things will mostly be used by Big Tech for their A.I. data-centers playing the Good Samaritan with their c…

Terrorists are only one piece of the issue. Corporations and "Responsible Adults" have done more to harm nuclear power in this country than any terrorist act has.

ConEd and Three Mile Island meltdown brought out a mass of normal people to chant "Hell No! We won't Glow!"

Hanford in Washington State.

San Onofre in So Cal.

Santa Susana Meltdown.

The reality is that everyone wants nuclear, but no one wants to live near a nuclear power plant.

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

#67

Post by bb88 »

testing22321 wrote: post #15
unglaublich wrote: post #9

Earlier quoted context omitted.

Well, gas and oil plants are actively emitting pollutants that kill thousands. And nuclear still is the safest energy sort available.

> And nuclear still is the safest energy sort available. Surely solar is orders of magnitude safer.

The potential for widespread radiation leakage from nuclear doesn't exist with wind or solar. I would think a terrorist would hit a nuclear power plant over any wind or solar farms.

The Chernobyl exclusion zone will remain uninhabitable for the next 20,000 years.

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

#68

Post by bell-cot »

DennisP wrote: post #43
bell-cot wrote: post #28

Nuclear power's biggest problem is that it attracted, even back in the 1940's, a figurative army of techno-utopians - whose pie-in-the-sky promises of electric power too cheap meter, flying cars, and better-than-Santa's-sleigh safety were not quickly and loudly contradicted by people who knew better. Probably didn't help that many of those keeping quiet had obvious short-term interests in promoting "nuclear everythin…

Sure, and none of solar's advocates are utopian at all .

The general public doesn't care about utopian-measuring contests between different groups of zealots. They want cheap electricity on demand, safety, and a sense of control. Solar does a pretty good job of offering that. Nuclear? Nope.

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

#69

Post by fasterik »

bryanlarsen wrote: post #45
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.

> firm That's the opposite of what you want. You want something that is cost-effective to operate at a 10%, 1% or 0.1% duty cycle. Like nat gas or hydro. Not nuclear. And overbuilding isn't the only lever you have to ensure coverage meets your target 99.99% level -- geographic diversity works really well (the wind is always blowing somewhere), and wind power production is usually negatively correlated with solar powe…

Natural gas and hydro are firm power. You're correct that nuclear is not a good backup power source, but that's not the suggestion. The question is whether adding high-capacity-factor firm generation reduces total system cost. In regions where hydro and geothermal are unavailable, nuclear is the next best low-carbon option. I think you're underestimating the costs and difficulties associated with 100% renewables, especially transmission capacity between regions.

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

#70

Post by bryanlarsen »

fasterik wrote: post #69
bryanlarsen wrote: post #45

Earlier quoted context omitted.

> firm That's the opposite of what you want. You want something that is cost-effective to operate at a 10%, 1% or 0.1% duty cycle. Like nat gas or hydro. Not nuclear. And overbuilding isn't the only lever you have to ensure coverage meets your target 99.99% level -- geographic diversity works really well (the wind is always blowing somewhere), and wind power production is usually negatively correlated with solar powe…

Natural gas and hydro are firm power. You're correct that nuclear is not a good backup power source, but that's not the suggestion. The question is whether adding high-capacity-factor firm generation reduces total system cost. In regions where hydro and geothermal are unavailable, nuclear is the next best low-carbon option. I think you're underestimating the costs and difficulties associated with 100% renewables, esp…

I think you're underestimating the costs and difficulties associated with 99.99% renewables and/or using it as a straw man against the highly inexpensive and achievable 95% renewables.

You're also underestimating the costs of using nuclear to achieve 99.99% reliability on top of a grid with 95% renewables: in that scenario you need nuclear capable of supplying ~100% of your power. In which case you might as well ditch the renewables. But the world does not have the quadrillions needed to go 100% nuclear. The world does have the 10s of trillions needed to go 95-99% renewable.

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