The point of embedding the isotopes is that it captures the beta radiation. Also, if you had one of these batteries next to your head, your head would be the greater source of radiation (from gamma rays).

That's like saying fire is a terrible idea. Or electricity. There are ways of using them that are terrible ideas, but we've also figured out very beneficial uses for them.

When we built our nuclear fleet, hydropower was the only other clean energy source which had the ability to displace coal, and hydropower was geographically limited. To the degree old-tech nuclear was able do displace coal, it saved many hundreds of thousands of lives that would otherwise have been cut short, and avoided millions of health crisis events, and no telling how many hundreds of billions in medical costs. It seems unlikely that all those people who benefited were rich already.

Even if that is granted, that would only rule out certain kinds of nuclear power. There are other ways of doing nuclear which would not have that vulnerability.

And we will probably also need to do some solar radiation management, at least for a while. The bizarre irony of our times is that the fight against developing better nuclear, against expanding nuclear energy use (not just for electricity), against developing point source capture that would work with fossil fuels (eg. Allam Cycle), against building direct air capture, against building CO2 pipelines, against industrial scale underground CO2 sequestration, against ocean sequestration, and against any investigation of solar radiation management is overwhelmingly coming from the climate activist segment of the population that claims to be the most alarmed about net global warming. They denounce all of those as needless and dangerous distractions and false solutions and will accept no climate action except for building lots of wind and solar and batteries (in a "just" and "equitable" way, of course) and ending capitalism and banning the use of fossil fuels everywhere--which would actually accelerate warming if they got their wish when the combustion particulates quickly cleared out of the air. And so the strongest support for all of those other solutions is now coming from Republicans, and red states, and oil companies. At some point, we seem to have fallen into opposite-world.

Not the first time that anti-nukes have produced unhinged "data" that is at odds with all the mainstream findings.

I'm going by the accounts from ORNL researchers from that time. For example, at 31:13 is Dick Engel's account, and others I heard were similar. https://www.youtube.com/watch?... Shaw did not communicate directly with staff or researchers, so these are all necessarily second-hand accounts. There was some question whether Shaw had the authority, but he was Rickover's man, so it doesn't look like anyone challenged him directly on that. But the directive was a clear enough that several have made a point of saying they did not follow the instructions and they kept their research. (BTW, Engel has elsewhere made the point that every reactor research program he ever worked on in his career was canceled before completion.)

Yes, it had problems. Back in the slide rule era, most of this research was trial and error. and all the other government lab nuclear research programs had problems too. But that doesn't help to establish that the government lab approach is the best way.

I already addressed this. The old-tech industry at that time was enjoying a comfortable monopoly. They had no reason to go to the expense and bother to try to change anything--especially when there was little chance of getting anything new through the NRC. The solution to that is to break down the monopoly system (created, in part, by the NRC) and let competition do its thing.

Or at least, it needs to have a realistic potential to be profitable. And even long-shot investments can be attractive if the profit potential is large enough.

They have cooperative ventures with foreign private companies, they buy or just copy technology developed elsewhere, and the Chinese government itself often operates like a mega-company, so the public-private distinction may not have much meaning in China.

But ideally it should be rational oversight. You don't want the regulators to be an obstacle to improving public health and safety--as the NRC has been.

Some ideas are so bad they have an almost epic greatness about them. The NRC's original licensing scheme, called Part 50, was 50 pages long, and there was a lot of confusion about how it could be applied to non-water-cooled designs. In response to a Congressional mandate to develop a simpler and more streamlined licensing option for new designs, the NRC staff worked on the problem for four years, and then submitted a proposed Part 53 which was simplified and streamlined down to 1,100 pages. And that's in the area of regulation--which is all they know how to do. If you gave the NRC permission to build nuclear power plants, they would simply never build a nuclear power plant. If you gave them a mandate to expeditiously design and build a fleet of nuclear power plants, given their expensive, bureaucratic, opposite-world approach to doing anything, I expect that after 90 years of staff turnovers and deadline extensions, they'd finally produce one power plant for a half-trillion dollars, and it would suck power from the grid.

Who is trivializing it? Designing every part of their power plant to be replaceable--which also makes every part of it upgradeable--is a great way to maximize the advantages of modular design. But the "question" about how fast 316 stainless degrades under neutron bombardment has already been studied for durations sufficient to establish a usable service life for the vessels. And then the retired empty vessels can be crushed into cubes and set aside for a few decades before recycling them.

And for nearly three years, they've been pushing their build permit application through the NRC, and that's only now issuing. If they can hold to the build schedule they've set for themselves, it will take them roughly the same amount of time to actually build the reactor as it took to obtain the permission to build it in the first place (and that's for a first-of-its-kind reactor without benefit of mass production).

Do you imagine that billionaires hand-pick all their investments? Why do you think they create investment companies?

For big, old-tech reactors, I think our build rate in the U.S. should be zero. The next-gen teams working on smaller modular designs are aiming for build times more like 2 years, with many simultaneous builds possible. That's the model we should be striving for. Even with the later start, that approach will quickly overtake the old ways of building nuclear--possibly in less time than it would take to build any more old-tech units.

The economic model is just the engine for getting it done faster, better, and on a global scale, within the system we have now.

It's possible to support smart and beneficial uses of fire, while also opposing the stupendously bad and dumb uses of fire. Same thing with electricity. In like manner, there are many people who support smart uses of nuclear energy who also happen to think reactors which can melt down are not particularly smart. They see the potential of better nuclear to not only help combat climate change, and ocean acidification, and to prevent millions of deaths from coal, and to help lift billions out of energy poverty, but also to help retire the aging old-tech reactors sooner.

We don't have to address any of the social problems which could lead to meltdowns if we go to reactors which cannot have meltdowns.

Different kinds of nuclear will have different levels of opposition or support. There will always be majority opposition everywhere for building another Soviet RBMK reactor. Support for more builds of old-tech Western reactors is stronger, but probably still below majority support in the U.S. But support for developing new kinds of reactors is already a majority position in the U.S., and that share is likely to grow when we actually have a successful demo reactor.

Or, here's another possibility. You have misconceptions about climate change. You seem to think it's all about halting the further release of fossil fuel emissions. That's not even half the challenge. If that's all we did, the result would be that the pace at which the world is warming would rapidly increase to roughly double the pace of warming we have now. Because if you end all fossil combustion emissions, that also ends the fossil particulate emissions, which have a shading/cooling effect that is masking about half of the warming potential for the greenhouse gases that are already in the air. So if we actually want to halt our warming, we will either need to dim the incoming sunlight, or we will need to remove way more than a half-trillion tonnes of CO2 from the air--and we'll need to do it in far less time than it took to release that CO2 in the first place. Planting trees and changing agricultural practices will at most provide a tiny fraction of the drawdown rate that we'll need--which means we'll need massive industrial CO2 removal--and we'll need a huge supply of clean energy to drive it.

In my case, I was an anti-nuke for most of my life. I only came around to supporting the development of better nuclear around ten years ago. I'm still opposed to some kinds of nuclear, but everyone is.

I don't address social changes that would not be needed for better kinds of nuclear precisely because they are not needed.

In the U.S., the government has already been privatized.

The human nature problem is why certain kinds of social reforms are highly unlikely to happen. Which is why I look for solutions which can work with the social, cultural, political and economic realities we have.

Nobody has those.

Flexible nuclear could help wind and solar.

It's possible that no more old-tech nuclear plants will be built in the U.S. But that possibility will be made more likely by the development of better nuclear.

A lot of technology that is routine today would have been considered a miracle not long ago. But technological advances have never needed magic or miracles. Physics shows how the technology that would solve all the problems you are talking about could work. The only question at this point is whether it can make it through the regulatory process and still be economically viable.

Only some kinds of nuclear power plants can have a meltdown. I'd be happy to live right next to a molten-salt nuclear power plant--especially if it meant that somewhere, a coal plant that was routinely killing people could be shut down.

I'd still be interested to know what you meant when you said nuclear compromises safety and emissions for billionaires' profit. Does that mean you don't want the safety and low emissions if that means billionaires will profit?

When Rickover decided the Navy's pressurized, water-cooled reactor design would be the best one for civilian power, that's the path we were set on, even though a number of nuclear engineers felt it was an inferior path. Alvin Weinberg developed the reactor Rickover chose, and he opposed using it for civilian power. His team at Oak Ridge had shown there was more promise in molten salt reactors, and they had a big success in their MSR experiment. And then Nixon shut them down for political reasons, because he wanted their funding to go to California--his home state. They were instructed to destroy all their research findings, and it was only through their disregard for those orders that most of that work was preserved. When Weinberg raised objections to the course Rickover had chosen, Rickover's minions had him ousted from his position as head of Oak Ridge. Basically all nuclear engineering research in the U.S. was halted after that, except for work on sodium-cooled fast reactors. That eventually culminated in the Integral Fast Reactor project--which was killed just prior to completion--for political reasons--by Clinton, Gore, and Kerry. So basically, from 1950 onward, all of the U.S. government lab-developed nuclear power research never reached completion. One public-private venture with a gas reactor operated briefly, but otherwise, none of these government-developed reactors went into service. And even if the Integral Fast Reactor project had been completed, a civilian version would have been even more expensive than conventional old-tech nuclear. Government labs can be great at advancing fundamental theoretical research, but their record on advancing civilian nuclear power engineering is overwhelmingly one of failure.

It does? So when wind or solar farms get subsidies, that means those aren't private ventures? With nuclear power support, one hand may sometimes give, but the other hand always takes away. It cost NuScale $500 million just to get through Part 1 of their licensing application. $629 million won't even cover the government fees and the work they will have to do to get through the regulatory process.

All of which went nowhere. Oh, maybe one of them could have gone somewhere... eventually. But that's another problem with government labs. What is their incentive to do anything quickly? (Remember sequencing the human genome?) And what is their incentive to make anything that's market competitive? Have you noticed some of the new combinations that the private teams have settled on? Moltex and Southern Co. are developing molten salt fast reactors, for example. We had one set of labs that did fast-reactor research, and another lab that did molten-salt research, but the two were never combined. Why? Balkanization. The Argonne-led team would not look into molten salts, because Oak Ridge had more expertise in that area, and any such research could be taken away and handed over to them. Oak Ridge couldn't touch fast reactor research for the same reason. That's also why no lab ever combined Triso with molten salt--despite the clear advantages over gas-cooling. Private teams are free to assemble the best ideas from wherever they find them without having to worry that their research might be taken away because they stepped into some other lab's area.

That is really not the same as development in government labs,

On paper? I think you might have missed what a huge revolution to nuclear engineering computer modeling and simulations have been. That seems weird in a tech forum.

And China is running with that research. But I think Kairos has a better idea.

Like at Oak Ridge--before that was killed.

The main obstacles to doing anything new a few decades ago were 1) the established industry had total dominance and they were comfortable with the way things were. And 2) very high regulatory costs and the uncertainty that comes from an abysmal record of approving anything new, and landing a disproportionate burden on first movers, pretty much ensured there wouldn't be any first movers.

Kairos will be using a clean salt, which avoids the corrosion issues that showed up in fuel salts--especially from tellurium. So they'll be able to stamp their reactor vessel out of common 316 stainless. It will still accumulate neutron damage, but their solution to that is just to swap out the reactor vessel on a regular basis. They won't have to show that it can last for decades.

Bloomberg is one of the main investors in Kairos. Does he seem like someone who doesn't know how to invest? If Kairos eventually decides to go public, I'll buy some of their stock, and I have no expectation of living long enough to ever see a return. It'll do more good than any political donation I ever made, and there are a lot of people who feel the same way I do. And when the stakes concern the future of the planet, there are even a few wealthy people who care more about that than about adding to vast riches they'll never be able to spend. If nothing else, some of them are aware how quickly their wealth can lose its value when the world descends into catastrophe and chaos.

Because the old way won't deliver what we need now, and because we have much better options now.

Interesting. Each of the new reactors at 90% capacity factor will put out roughly a gigawatt of electric power on average, or 8766 million kWh per year. At $0.25/kWh, that would be $2.191 billion per year revenue per reactor. So over, say, 40 years, that would be $87 .7 billion in revenue per reactor, and only one extension to 60 years would take that to over $131 billion per reactor--when each reactor had a build cost of around $17.5 billion. So the math suggests the build cost represents only a small fraction of this needed 25 cents per kWh minimum price. What accounts for the rest of it?

Oops. Missed the tiny green-on-grey print.

There is an argument to be made that such catastrophic potential is not "safe".

Nuclear power was originally developed on the government-lab model. That did not go well. The real revolution that is taking place in nuclear power today is that the bulk of development work is taking place in the private sector--with some input and assistance from government labs. There are now dozens of teams working on different approaches to nuclear power--a level of activity which never existed under the government lab model. In the particular case of molten-salt cooling with Triso fuel balls, Kairos Power has already set up the largest fluoride salt test system in the world, a second unit is under construction, and a third is in development. They've got a molten salt production facility set up and they are setting up a fuel production line at Los Alamos. And they recently got approval to build their first Hermes demo reactor at Oak Ridge, with an application for two more Hermes reactors already submitted. They plan to start construction on Hermes unit 1 in 2024, and they think they can get it operational in 2026--assuming no snags in getting their fuel production line NRC certified, in obtaining a fuel production permit, obtaining a fuel transport permit, and in getting a license to actually load the fuel and operate the Hermes reactor.

We have the ability to evaluate the safety case for different kinds of reactors even before they get built, and we can also do validation of key parts of the models without having to build complete systems. In the version of Triso that Kairos is planning to use, they characterized the failure rate by taking samples up to 19% burnup, and then subjecting them to 3000 deg. F for ten days, and found a rate of less than ten failures per million grains of fuel--with nearly all of those failures being caused a some residual production defects--so even that tiny rate could be improved even further. That is a way more severe test than the fuel is ever likely to experience, and it doesn't even include the added protections of the grains being embedded in tough multi-layer balls, inside a carbide shell, and floating in molten salt. We can definitely compare that to the safety of fuel we know is prone to melting down in any of dozens of common fault scenarios, and the disaster potential of such meltdowns.

That's not how we establish safety. Running a test reactor and not having a problem with it would not establish that it is safe under all circumstances, and there's no way we could subject a test reactor to all the hazard circumstances which might affect it in operation. Nobody is going to crash an airliner into a demo reactor just to see what happens, for example. The safety case is built on science, engineering, and now, computer modeling and simulations. You can't go to the NRC and ask for a build permit without making a safety case for it, and if safety could only be established by actual performance, we'd never be able to build anything new. The demo reactors can help to establish the precision of the models, but the models have to be robust enough to pass the technical review board in the first place before anything can get built. And in the particular case of Triso fuel, we don't need to build an entire reactor just to confirm that it will never experience a meltdown. That can be established by work on the fuel itself.

And there was also an instance of balls breaking up in a German plant, and some contaminants escaping. But all of those were gas-cooled. In hot molten salt coolant, the balls have just slightly lighter than neutral buoyancy, so the rub pressure between the balls is quite low. Molten salt also acts like a heavy lubricant. And most of the other fuel ball designs did not have a hard carbide exterior. And even if some contaminants could somehow escape the balls, the molten salt itself binds to the worst contaminant isotopes (of iodine, cesium, and strontium).

What if the laser printer was designed so that every part could be easily popped out and replaced with a new module--including upgraded modules as development continues? What if standard operating procedure was to replace every part long before it could become worn out? And what if the relative scale of the disaster potential was only about as bad as for the laser printer?

Ah, okay. I misunderstood your point. But only because you failed to sufficiently qualify your position. So when you said "I have yet to see a nuclear power plant that can be run safely ..." etc What you really meant by that is only that you have yet to see a PWR or LWR power plant that can be run safely. And likewise, we should interpret your other remarks as: "You want PWR or LWR nuke? Fix the social problems." And "nobody has been able to solve the tech problems with PWR or LWR nukes." And "So no PWR or LWR nukes." And that would be a considerably more restrained position. But it also means we don't have to find social solutions for PWR and LWR reactors. We can just go to different kinds of reactors.

I think the problem was a water line needed for instrumentation froze, producing an instrument error, triggering an automatic shut-down. It was probably an instrument related to cooling, so it may have been reported as a frozen line shutting down a cooling system.