Hacker News new | past | comments | ask | show | jobs | submit login
Safer Nuclear Reactors Are on the Way (scientificamerican.com)
285 points by tshannon 4 months ago | hide | past | web | favorite | 292 comments

I'm slightly skeptical of accident tolerant fuels (ATF).

In terms of deaths per kWh generated, nuclear is already the safest form of energy generation we have.

Where nuclear fails, and where improvement is desperately needed, is ability to deliver on budget and within schedule.

What is NOT needed is minor incremental safety improvements at significant cost (e.g. ATF's that the article discusses).

Now, more substantial improvements, e.g. non-LWR designs, passive walk-away safety, modular design, etc., I'm all for those.

Hear hear! I think the nuclear industry struggles with finding a balance between sunk costs (e.g. TRISO fuel development under NGNP, the TREAT reactor, ATR, the BISON fuel performance code), and what advances the nuclear industry really needs to survive and thrive. At a NRC meeting a while ago, one of the members of the ACRS asked pointedly what regulatory relief they expect to get from ATF. No one knew. Is the NRC going to relax a bunch of regs when we have ATF and somehow allow nuclear to be cheaper without compromising safety? No way.

We need ways to minimize financing costs during construction, and get the number of staff required at operating plants way down to decrease O&M. My favorite solution? Shipyard-constructed nukes on floating platforms, tugged to locations for power and tugged back to port for maintenance. Solves almost all problems assuming you can get them to operate largely autonomously. In attacks or ship collisions, design it to sink safely and cool itself with seawater. Build in a recovery operation to the design.

Also, the nuclear industry really needs to find ways to consolidate effort. There are literally 50+ SMR designs in work right now, and dozens more larger reactors. The industry is wayyy to small to be fighting over limited investor and government money to develop that many reactors in isolation.

> Shipyard-constructed nukes on floating platforms, tugged to locations for power and tugged back to port for maintenance.

What’s your opinion on Thorcon?

Also I’m wondering if you have some thoughts on this: I’ve been wondering what holds us back from taking a scale out approach rather than a scale up approach we have now (e.g. with EPR design now producing 1.6GW). Instead couldn’t we pump out naval sized nuclear plants in mass production style since we can apparently still build those and my limited understanding is their smaller size and output makes them safer (less decay heat etc). Ship those around as needed for refueling. And just have a couple dozen on each site to produce the equivalent power. It would combine a national strategic need that we have to do anyway (naval nuclear power), with another need that we seem to be failing to do (getting back on the horse with producing reliable clean power).

Thorcon is awesome. I love their style and logic. They're pretty open-door, they have the boldest low-ball cost estimate I've ever seen, and they have a solid set of reasoning for why it's going to be that cheap (e.g. The Tale of Two Ships [1]).

I don't really like that it's fluid fuel though. As I said in another comment, the unknown remote maintenance implications of that are very far from hashed out, and will very likely be terribly expensive for a fairly long shakedown/learning period. Fluid fuel is a good end goal. But don't get me talking about fluid fuel in a near-term first-of-a-kind plant with a low-ball operation/maintenance cost estimate. I also don't like that if they succeed, they have a very large waste stream of super radioactive large-scale components (that get swapped out ever ~5 years and put... where? That's gonna be a problem). Also, working primarily with a country with inexperienced/non-existant nuclear institutions for a very advanced reactor (Indoensia) is probably not going to work. I get the logic though, bootstrap a new nuclear regime without the old regulations. Problem is, fluid fuel reactors have a variety of postulated novel ways to increase source term. That will take work to license. A lot of work. Experimental work, in neutron irradiation.

I just wish they'd try a small light-water reactor with their shipyard construction experience first and take it from there.

I also freaking love that they use LaTeX.

[1] http://thorconpower.com/docs/two_ships.pdf

> e.g. The Tale of Two Ships [1]

Thanks, that's quite a story!

> I don't really like that it's fluid fuel though.

I have some misgivings about this as well. A water-soluble fuel salt in a thin-skinned (compared to a high pressure LWR) vessel on a ship, what could possibly go wrong?

(I'm a fan of MSR's and I'd love to see them deployed, but I'd prefer them on dry land thank-you-very-much)

> As I said in another comment, the unknown remote maintenance implications of that are very far from hashed out, and will very likely be terribly expensive for a fairly long shakedown/learning period. Fluid fuel is a good end goal. But don't get me talking about fluid fuel in a near-term first-of-a-kind plant with a low-ball operation/maintenance cost estimate.

Agreed, but IIUC Thorcon, similarly to Terrestrial, are planning to replace the entire reactor vessel with the primary circuit every few years (5/7/?). So AFAIK the plan is not to do any maintenance of the reactor vessel. Guess you have to hope one of the primary pumps doesn't need a new bearing 1 month after commissioning, then, eh?

> I just wish they'd try a small light-water reactor with their shipyard construction experience first and take it from there.

Yes, though it seems passively safe LWR's are quite massive. Nuscale reactor vessel is a frickin' 700 tons for a paltry 60 MWe. Thorcon reactor is 250 MWe (or is it 500, their materials are somewhat confusing?). Would a passively safe 250 MWe LWR fit on a ship, along with a pressure dome to handle a LOCA?

"Shipyard-constructed nukes on floating platforms..."

Hmmmm... This reminds me of the nuclear armed b52s discussed in "command and control". Are all of the failure modes actually safe? And is building a movable platform contributing to the risk of failure? Feel like for nuclear, KISS is particularly important.

There is a great deal of experience with putting reactors on ships. On the other hand real world experience for putting reactors on planes is very limited, and what little experience there is suggests that shielding would be minimal (shadow shielding for the pilot/copilot only) or nonexistent.

Because nuclear power such a charged issue (pun intended), transparency and trust is especially important.

The nuclear struggles with genuine transparency, which, imho, would go further than anything else to shifting the public's feelings on nuclear power.

Totally agree. Nuclear technology was born in secrecy but civilian nuclear energy stands to benefit from much more openness now. I've been hearing people talking about finding ways around institutional friction via various open-source inspired collaboration and design practices. Could be hopeful.

> Shipyard-constructed nukes on floating platforms, tugged to locations for power and tugged back to port for maintenance.

Such as Akademik Lomonosov?

Precisely. Hopefully larger though, to really get that economy of scale. You can put up to 2 large GW-class LWRs on something much smaller than the Prelude.

deaths per kWh (or even various adjusted life year metrics) aren’t all that matters. Cost of cleaning up and other economic losses due to accidents also matter.

The Fukushima accident may not have caused much in the way of injury, but the cleanup is projected to cost over $100bn. It’s not so easy for nuclear power to compete when those costs are factored in.

So yes, passively safe reactors are a big deal in my book.

Fossil fuel is causing a whole lot more damage per kWh that we have to clean up. BP estimated 61 billion USD to clean up its oil spill in 2010.

I would say nuclear is already competetive when compared to that.

Also, impending climate disaster that's been building for decades. The cost of that is borderline incalculable.

That sounds like an interview estimation question.

Presume total extinction due to climate emergency.

GWP = annual gross world product.

r = estimate of risk that we kill ourselves through other means per year e.g. 1 in 100 due to nuclear war.

Presume zero growth (e.g. world growth is offset by population growth, environmental damage, discount rate).


Cost = GWP / 2r

”Fossil fuels doesn’t change the climate, humans change the climate, we merely provide the means and are not liable for cleaning up this mess.”

"Economic damage of the Chernobyl accident is estimated at $235 billion for 30 years on after the explosion" (source: UNDP)

Sounds low...

That's like arguing internal combustion cars are better than electric cars, because they're cleaner than horses.

The only thing that matters in reality is the investors making a profit. If nuclear out competed other generation on that basis it would be everywhere now, regardless of whether it was safe or not. cf Hydroelectric. A dam destroys more land for a far longer time than Fukushima has left contaminated today. And as for deaths, dam failures have a truly horrifying track record: https://en.wikipedia.org/wiki/Dam_failure 100 people died just building the Hover dam. Yet we are likely to see more Hydro, not less.

You don't see nuclear for one reason: it's high risk with low returns. It isn't high risk because nuclear reactors regularly go bang. It's high risk because a plant has to operate profitability for 40 years in order to make a return, and 40 years is too far out so safely predict anything. 40 years ago there was no internet and global warming wasn't something we knew about. The plant going bang is just one of many things that could render it unprofitable. There could be fuel supply problems (cf Iran), or the demand could move away (eg, a aluminium smelter could close down), or a cheaper technology could come along, or an earth quake, or a tsunami.

The new designs in the article seem to solve some problems. Being tow-able means if the current market folds you can move it somewhere else for example, and being small means there is less money at risk. But geezzz - 4 years to build. In 4 years it is possible the price of solar or wild could drop by 40%.

What is more important than deaths/twh? Costs? I would disagree. Perhaps, area lost to contamination (e. g. Chernobyl exclusion zone, Fukushima area). But then, how much is lost/flooded due to coal excavation, hydro dam flooding, etc.

I don't think amluto said the clean-up costs were more important than deaths/kwh. The point is that these improvements are necessary and welcome even though nuclear is already safer than the options, for reasons other than safety.


If I were a nuclear regulator, I would not permit construction of a plant that could, by design, be a danger to anything other than itself if it lost power. I would also consider requiring existing plants to retrofit themselves to have the same property if the technology became available.

> "I would not permit construction of a plant that could, by design, be a danger to anything other than itself if it lost power."

What about a plant that's a danger to others when it's running optimally within design spec, as every single coal fired plant on this planet is? Do you apply this standard to all power plants, or only nuclear?

I think that, even in an appropriately regulated and taxed environment, coal has a place. In particular, fly ash can replace a respectable fraction of the cement used in concrete. If a coal-fired power plant can scrub its emissions to remove particulates and CO2, it may be cost effective as a source of fly ash compared to the (taxed) cost of cement production.

I'm skeptical that "clean coal" will ever be cost-effective when considered purely as a source of power in most locations.

As far as I'm aware coal (particularly coke) plays a vital role in the production of steel, so I don't expect we'll do away with it anytime soon. But it's very frustrating to see coal being given a free pass by critics of nuclear, particularly when those critics call themselves environmentalists.

One can make steel without using coal or coke. Some steel is made this way even today ("Direct Reduced Iron", particularly the mode where iron ore is reduced with syngas made with natural gas). Hydrogen could be used instead of syngas to do this reduction, and the amount of carbon that would be needed to make the final alloy would be small, and could be sourced from non-fossil sources.

> coal has a place [snip] in particular, fly ash can replace a respectable fraction of the cement used in concrete.

AFAIK fly ash is mostly used as a replacement for other filler (sand etc)... Using fly ash doesn't change the amount of CO2 produced per m3 of concrete.

I am struggling to understand what your point is here.

Also fly ash is generally a single digit percentage by coal weight burnt. So say 90% of coal burns with oxygen, most of which ends up as CO2 (by weight). Using the fly ash waste (from electricity generation) in concrete makes sense. Burning coal to indirectly justify making cement does not.

As I understand it, fly ash can replace a fair amount of the cement, and cement production is CO2-intensive.

Your understanding is correct, fly ash can be used as a substitute for portland cement. It's apparently chemically similar to how the Romans used to use volcanic ash in their concrete mixes. A lot of cement sold these days is a mixture of fly ash and portland cement.

My impression is that fly ash involves the production of more CO2 than burning coal to produce an equivalent amount of portland cement, but it's worth it when you're burning coal anyway and fly ash is basically free as a byproduct. So in practice it essentially offsets CO2 emissions from burning coal, but only partially.

That's just the impression I've gotten though, I don't have any numbers for any of it.

I would say any plant that was built before maybe the 2000s, which is admittedly a lot, should just be decommissioned, with more modern plants replacing them. Our main risks with nuclear plants is that most of the plants are at or around the 50 year point, which not only is about their original planned lifespan, but also absolutely ancient in terms of design and technology. Yeah they have been improved, but only so much as an already built plant can be modified for cheap. When people talk about nuclear safety, they are thinking about plants designed only 15 years after we invented nuclear technology. Talking about the safety of Fukushima, or Chernobyl, or many other plants is the equivalent of discussing the crash safety of a Model-T instead of a 2010+ model car, and has people wondering if cars should even be allowed based on the Model-T's design.

It's important in terms of adoption. Fukushima destroyed the economics of Japanese nuclear power. One accident like that per 100 years and nuclear suddenly becomes very expensive.

global warming has sever long term consequences for economies as well. People need energy, problem is that the costs of dirty energy are spread out and “average Joe” doesn’t think of them as energy costs (pollution, worse health, wars for oil, etc.)

That’s not accurate. “Rooftop” solar is minimally dangerous to install, but large scale solar fields on empty land is extremely safe per kWh.

PS: Nuclear also has many deaths not generally included in these statistics. As building and operating a power plant is not the only risky things you need to do to have nuclear power. Ex: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4164879/

It depends if you're including the carbon footprint of the entire solar panel build/shipment process (from raw materials to shipping/etc). I'm not sure of the numbers, but installation is a negligible part of the total solar impact to the environment.

If you use that level of accounting nuclear plants also have a sizeable footprint just from their concrete useage in construction.

I am a fan of nuclear but current economics seem against it even if they are driven by irrational reactions.

But doesn't that carbon footprint assume that the energy to manufacture and transport the panels comes from fossil fuels? Then it seems we would eventually reach a point where a sufficient fraction of the energy to produce and transport would itself come from solar, leading to a reduction and eventual elimination of that carbon footprint.

The ability to deliver on budget and within schedule is dependent more on political than technological development. Arbitrary delays caused by political meddling (including with pretext of safety concerns) are a significant part of the schedule problems.

However, minor incremental safety improvements may be a tool in addressing this political risk - though it is true that cost still needs to be controlled.

From a tech point of view, you're probably right. But one of the biggest things holding back nuclear energy is public perception and politics. Maybe the biggest thing.

If you can say "prevents the type of accident that happened at Fukushima", those could be powerful words. Fear is often not rational, and it's human nature to be acutely fearful of things you have seen happen (even if they aren't actually larger risks). Even if the actual safety impact is small, something that hits directly at the thing people are worried about could have a large impact on the political reality.

Yes, it's inefficient to have to placate people who don't know a lot about it, but if nuclear is to succeed, we have to realize that the majority of people are never going to understand the risks in depth. It seems worthwhile to spend some resources just to make it so "nuclear" is less of a scary word.

In the HBO series Chernobyl they claim to have been hours away from causing a much larger incident killing about 60 million people and making large parts of Europe and Asia uninhabitable.

Is there truth to this claim?

If so, and if such failure modes are possible, I’d say that current deaths per kWh is not be the best way to estimate risk.

> Is there truth to this claim?

No, there isn't. They invented quite some nonsense to add drama and the reactors blowing up like thermonuclear bombs is among that.

https://theconversation.com/ten-times-the-chernobyl-televisi... point 5

It's entertainment, not a documentary.

Everytime i read this claim i feel bored, because there is no substance to it, justified by uncounted people saying so because someone said so, therefore it has to be "the truth".

What do you make of people who have been there and worked there afterwards, which came to a different conclusion? Conspiracy theo- or terrorists?





The whole point of the "docudrama" was pointing this out, but failing to point out the next level of this error.

And most of you are regurgitating the same shit over and over again, in blissfull ignorance.

In this emotional response full of links, you forgot to articulate your point.

Sigh. Someone asked if what has been shown in the tv-series could really happen. Someone answered naaa, never ever, absolute BS. That would be the feared steam explosion if the molten corium reached ground water and would produce another large "dirty bomb". That was the feared scenario afterwards. The links i posted support a wholly different chain of events, meaning that the explosions did not occur for the reasons generally assumed, and have been indeed in parts been of a nuclear nature, but not like a "fizzling nuke", rather something different, not seen up until then. Therefore not understood. All based on the detected isotopes at different places. Which makes no sense if the story is told as it is told. Which leads to the question why building a big dome over that thing, if 90% of the reactor mass have been vaporized, as the reinterpretation suggests. This is also supported by people who have been in the wreckage with floor plans several times over the years and did not find enough material in it to account for the 90% reactor mass assumed in the wreckage, and about 10% blown away.

So my point should have been:

The Tv show had good production values, but told the story wrong, ignoring the new interpretations which meanwhile became available. Then someone asks about something which couldn't even happen according to that new interpretation, because not enough molten corium in there anymore to make a good and large dirty bomb. Which could have happened IF the corium had been there in large amounts as has been assumed up until now. But it is mostly gone. So not even wrong!

Wasn't the whole point of the show to show how wrong assumptions and mis/disinformation leads to catatsrophe? Especially in the end of the last episode? During the trial?

I think his point was that, regardless of the chances that these doomsday scenarios could occur, experts on site at the time warned that they would, which is precisely what the show depicted.

One of the comments I heard was that while the physicists knew that wasn't possible, at that point, they were 1) battling with politicians who weren't overly concerned with anything except perception, and their own asses, and 2) wouldn't know enough to call them on the lie, and felt that claiming such a thing was possible might "wake them up" and hopefully provide some forward progress.

Did it actually happen that way though? It’s my understanding that we don’t know (the people at those meetings are dead) and HBO/Sky made it up in a way to add drama.

Likewise with the 3 plant workers on a suicide mission to open the sluice gates, who were supposedly sent to their deaths. They’re still alive and healthy today (except one who died of non-nuclear causes).

Well, at least with those workers? That actually happened, with those three men, and they were expected not to survive. (Water does a better job than many solids at absorbing radiation, I believe...).

Noted. Thanks for clearing that up.

Since they did state that some of the characters were made up I had some hope they’d be a bit careful about other things, such as this claim that didn’t add that much to the actual drama.

They probably should have added "Based on a true story" so you know it is partially fake.

Probably overblown. The show was good, but some parts were technically scientifically inaccurate. The claims about megaton explosion certainly were.

What precisely was said there? Perhaps they meant the fallout would be similar to that of a megaton range explosion? The long-lived fission products in a large NPP near the end of a fuel load are about the same as those from a 100MT nuclear bomb.

I don't have the HBO scene at hand, but I found this documentary on youtube which the scene was probably based on. Physicist Nesterenko says the experts concluded there was a possibility that the corium explosion due to contact with water tank could have magnitude of 3-5 megaton and that Minsk would be erased [1].

Now obviously the nuclear explosion of the corium is not entirely impossible, there are known mechanisms which could set it up. But even if it happened, it would not erase Minsk, that is not believable, because Minsk is too far away. So that puts the main claim into question. How probable such corium explosion is is not clear, some things about nuclear bombs which those experts knew are probably still classified, but internet pundits say not very likely.

[1] https://youtu.be/ZKV1piLjoa0?t=58

> Where nuclear fails, and where improvement is desperately needed, is ability to deliver on budget and within schedule.

Indeed, this is what is glanced over way too often with the urge of politicians and industry bureaucrats to rush builds of the bleeding edge and experimental designs.

The only economic nuclear power stations today were big, multi-gigawatt PWR and BRW designs with more than 4 reactors. In comparison to power output/fixed costs, all other factors pale in comparison.

Very good point. Incremental safety measures with an eye to swaying public opinion is pretty pointless as public opinion changes very slowly I imagine and we must be hitting the law of diminishing returns w.r.t this particular set of tech.

On the other hand a pure win would be figuring out how to enlarge the market share of nuclear by persuading those who are already willing but balk at the large up-front costs, the insurance, the regulatory environment, the long planning processes (etc. etc. – basically everything but the tech).

If the USA and the EU both made a commitment to doubling the share of nuclear tech in their jurisdictions to combat climate change (and we're going to need loads of cheap juice to power all those EVs) by streamlining the processes and creating an Atoms for Peace mark II umbrella that would make this HNer a happy camper.

Don't see it happening unfortunately. Every time this topic comes up I get so disheartened.

Public opinion won't matter at all until construction itself becomes a reliable process. There are plenty of sites willing to host nuclear, and as our current fleet ages out many sites would welcome replacement reactors to keep the community's economic base going.

However it's abundantly clear that the current tech's time has come and gone. The current designs can't be constructed in the US, as it becomes a Mexican standoff between utility, designer, and contractor, each just waiting to sue the others for what they assume will be inevitable and costly delays and construction/design errors.

The Rankine cycle for converting heat to electricity is just not super exciting any more, and wind/solar/storage may outcompete thermal electricity generation as an entire class of technologies.

From what I hear the US can barely maintain its roads, let alone build nuclear power plants, but why the gloom? We did it before, this time it really matters, so let’s put some money into saving the planet and get that x1e6 energy density going.

Maintaining roads is pretty trivial compared to building more nuclear, and we are very good at that as long as there's money allocated. When money is allocated for nuclear, we are not good at building, just as we are bad at nearly all massive multi-billion dollar builds.

We no longer have the project management skills and construction skills we had 50 years ago.

If you look back at the pre-Three Mike Island track record for construction, it isn't much better than our current, and fairly disastrous construction record from the past decade. There is a survivor bias when we look around at the currently running and constructed nuclear reactors.

Meanwhile, there's a route that requires far more scalable expansion, our current path of wind, water, solar and storage.

The US seems to be OK at building wind farms and solar farms.

Screw up 1% of the modules in a solar farm and output is down 1%.

Screw up 1% of the concrete pours for a nuclear power plant and it's a disaster.

The distributed nature of wind and solar makes building them, and training the workforce to build them, easier.

Exciting? Who cares if it is exciting? It's the most dense means of energy production that we have, in terms of cost, square footage, and like, every other positive metric I can think of.

In terms of cost, we are on the exponential improvement phase of the logistic technology curve for wind/solar/storage. For thermal energy, we are long past that. That's why "exciting" matters.

Already wind/solar/storage have beat nuclear on cost, are beating coal, and in many areas solar+storage is beating natural gas for new installs.

We don't know how much wind/solar/storage will improve on cost, but we know it will be quite a bit. We know that thermal generation of electricity is optimized to its max.

As far as dense energy production, what benefit does that have? If you want to stick a steam turbine on wheels, or a nuclear reactor in a submarine, that would make sense, but I'm not sure how it helps for the grid.

At some point it will dawn on us that the resources needed to build solar/wind is defined by the energy density available in these resources. Nuclear is basically invoking a deeper level of reality, one where energy is measured in MeV rather than paltry eV of chemical binding energy. Solar and wind are even less dense. It may be an old Physicist’s ramblings, but we have backed away from Prometheus’ fire way too soon to save ourselves.

With wind and solar we are capturing leftover energy from the sun's fusion; the internal amount of storage is not relevant.

With fossil fuels, we are simply using the stored energy from past fusion.

It's likely that we will start creating synthetic fuels from the electricity that comes from wind and solar, if you want a dense storage mechanism for keeping fuel close by for mobile applications or isolated sites.

There's nothing magical about nuclear, it's just a heat source. Unfortunately it's difficult to transmit heat long distances.

> As far as dense energy production, what benefit does that have?

So that we don't blanket the countryside with wind and solar farms? I would have thought that'd be obvious enough.

Also, very few people are really factoring in the environmental costs of repairing and recycling huge turbines and masses of solar pv panels – it's externalities like these (and other externalities besides) that are masking the true cost of renewable tech in the same way that environmental pollution masks the true cost of so-called fossil fuels.

Just you wait and see. The Chinese and Russians are forward thinking, increasing the allocation of atoms for peace in their energy mix.

The land requirements for renewable energy are a tiny fraction of that used for farming, density is not a concern.

Why would you think recycling turbines or panels or inverters is going to be onerous? The quantity of materials, and the nature of the materials do not seem in the least bit onerous.

> density is not a concern

I don't think this is true. We would need about 20,000 sq mi of solar to cover just our electricity needs today. Problem is, electricity is only ~38% of our energy usage. To replace all energy used (transportation, heating, industrial, etc) we need something more like 53,000 sq mi of solar. This would be like covering all of Iowa or New York with solar. Since panels only last around 30 years, we also need the infrastructure to produce, install, remove and recycle ~1,750 sq mi of solar panels per year.

Listing these numbers without context, one might think they are big. We have 1,400,000 sq mi of farmland (according to the 2007 stay I saw), so even if we use this prime space thats already been taken from nature, thats 1%-3% of farm land. We also have many other areas that are currently used by humans that we can cover. We cover something like 100,000 square miles with asphalt in the US, and that doesn't even directly produce revenue.

The numbers, with or without context, are big. Let's just say that it is an area the size of Iowa – that's an enormous amount of land to cover for electricity generation. To argue against that is ridiculous.

And I bet it would actually be a fair bit larger because of all the extra infrastructure you'd need to produce, process and recycle the solar panels. For some reason nuclear waste is a very big deal but wind and solar never appear to have any externalities. Funny that.

Imagine covering all that land with forest, or growing vegetables?

France is well known for nuclear being a high percentage of its electricity production. 75% – how many reactors? 58. Only 58!

I can't find your stat for asphalt. The one I found was: https://www.quora.com/How-much-land-in-the-United-States-is-... which says, “The estimate of roads in America is about 65000 square miles but Maybe 8% of that isn't asphalt. Plus This number would not include parking lots, driveways, private roads and other uses.”

I think an energy production source that takes up as much land as roads _is_ a huge amount of land. Imagine taking each road and covering some land somewhere in the equivalent amount in space with solar panels. That's mind-boggling.

> doesn't even directly produce revenue.

So what? Infrastructure doesn't directly produce revenue. Yet it enables all sorts of revenue generation. What sort of argument is that? You know what else doesn't even directly produce revenue? Electricity production.

You're using lots of subjective comparisons here.

Why is it an enormous amount of land to cover for electricity? Iowa is already 100% covered with farms, which use the sun for growing things. And we have 30x more land covered just for farming, much of it make-work to ensure that we have a massive oversupply of field corn and soybeans. Solar panels are a far less intensive use of the land than that sort of farming.

Why is only 58 sites for France's nuclear reactors a good thing? Can you connect to some sort of value system where such a count becomes a good thing?

My point about "doesn't even produce revenue" is that we covered up all that space without any sort of direct financial incentive to whoever lost that land; with solar, farmers can, and are, devoting their land to electricity production because it's a positive revenue stream for them.

I'm also having trouble contemplating the problem with solar panel waste. What problem do you think is created by that disposal? Logistics? Environmental?

"Mind boggling" could describe any of the industrial processes that happen every single day in our modern society. One could look at the vast amount of corn produced during harvest, and think "that's unbelievable," but it's not an argument against doing it.

The land issue is a red herring. This can be seen by looking at the contribution of the cost of land to the cost of renewable energy. It's small, especially in places where the land isn't even good enough for farming.

Now, maybe in the densest parts of Europe things could be different. This just means that in a renewable future, energy intensive industry leaves Europe. Europe going nuclear would not change this, as they still couldn't compete with the sun-drenched countries closer to the equator.

Problems with nuclear:

  - waste mgmt
  - safety
  - proliferation risk
    (for uranium-/plutonium-based reactors,
     not so much for thorium-based reactors)
  - outrageous construction costs
  - heat pollution (heat discharge into local waters)
  - baseload-only
  - slow to blackstart
Thorium reactor designs solve the first three issues only (unless they can be blackstarted soon after a blackout -- do thorium reactors suffer from poisoning?), in which case they'd solve four of the above problems. Or perhaps thorium reactors can be cheap to build? (I'll believe that when I see it, but only then will nuclear [fission] begin go be appealing.)

The only good things about nuclear are that the fuel is cheap (maybe) and it has no air pollution (barring accidents). That's not enough to justify the issues.

There's one more problem: cost per kwh. It might be competitive in the current market (though arguably it actually isn't). But to stay competitive in the future it will need to keep up with mass produced solar/wind continuing to drop in price. It seems solar + storage bids are continuing to break records and are already underbidding nuclear, even before considering subsidies. IMHO, prices will continue to drop over the next years/decades. Bids are currently going as low as 2 cents per kwh in some areas and prices dropping to below a cent might actually happen at some point.

Energy storage is much less of an issue if you can simply produce more than you need to offset e.g. cloudy days and use the excess energy to synthesize any of a wide range of fuels that can be stored, top up batteries, pump water to some reservoir, or power any of the many ways in which we can store energy. People are getting creative when it comes to energy storage. Energy storage cost is dropping rapidly as well.

Nuclear doesn't just need to get safer, it also needs to get vastly cheaper to keep up with this. IMHO if you are not designing for half a cent or less per kwh, you might as well not bother. My understanding is that current designs are off by factor 10 at least. At those prices, even the security needed to protect the facilities will be prohibitively expensive.

Nuclear isn’t intrinsically expensive. Most of the cost is due to safety regulations, which in principle safer designs would need less of.

Safer designs are the result of safety regulations, if you lift those regulations you will get less safe reactors. They might be cheaper but also less safe.

I think you misinterpret what I was saying. An actively cooled core needs lots of safety measures in place in order to make sure that the water pumps never fail, or if they do there are backup systems in place, and backup systems for those backup systems, etc. There's a physical cost to making all those mechanisms. Furthermore there is a regulatory and administrative cost to ensuring that those mechanisms would work across the entire industry.

On the other hand, something like the NuScale design takes an all-passive approach: it places a smaller fission core directly in a massive swimming pool that has enough water to passively cool the design all the way down. There are no moving parts to switch on in the case of failure. The way you handle a catastrophic failure is: you do nothing. It solves itself.

No moving-part safety mechanisms to install, just a big tank of water. No fallback mechanisms for those safety mechanisms, etc. Inspection is pretty easy: did the water level remain in range? Yes/no.

Cutting costs of safety inspections due to an inherently safer design doesn't mean a less-safe outcome.

And I simply disagreed with this assumption.

For reactors built here a significant part of cost is plain mismanagement, corruption and/or profiteering. This results in costly and less-safe reactors.

Don't know about others.

Partially this is certainly true and it is easy, since everybody assumes that the costs will increase, nobody is surprised that the reactor which should have costed 3 billion euros will cost over 10 billion euros in the end.

For a technology where the prices are decreasing, this is harder to do.


"Where nuclear fails, and where improvement is desperately needed, is ability to deliver on budget and within schedule."

Something that see nobody discussing and that I gave almost no thought to myself is the embedded carbon cost of the mining and enrichment of Uranium itself.

Never mind the building of the plant, etc., but the actual carbon expended to achieve a workable fissionable fuel.

This process was brought to my attention in the long, detailed chapter on Uranium enrichment in _No Immediate Danger: Volume One of Carbon Ideologies_ by William Vollmann.[1]

It's really quite amazing how many steps are involved and how expensive those steps are in terms of embedded carbon cost. In the absence of fully non-fossil-fuel power sources to do that mining and enrichment it is difficult to see how that process makes any sense absent the massive economic and military subsidies we have in place for gasoline/diesel.

[1] https://en.wikipedia.org/wiki/William_T._Vollmann

The cost of enriching uranium used to be a problem, then gas centrifuges replaced diffusion and reduced the energy cost by a factor of 50.

I'd say one of the biggest roadblocks to nuclear power right now is public opinion. Nobody wants one in their backyard because there's a lot of false information (and shows like Chernobyl don't help). Even though we're well into the safe area, showing that we're making them even safer might help sway public opinion to build one where it otherwise wouldn't have been at all, regardless of the multi-billion dollar cost and decade+ timetable.

But that's not the big roadblock to nuclear power. The main obstacle is that it's grossly uneconomic. Even in locations where the locals are nearly 100% for reactor, the reactors are not being built. The people controlling the money don't see them as good investments.

I personally would not mind having a nuclear plant in my backyard, but please, may I have something in return for the increased risk?

Something like lower property taxes would do. Or free electricity and heating for all residents.

I agree with you that it’s important to make nuclear reactors more cost efficient but also what you are leaving out is twofold. One, The costs of a cleanup after an accident is massive which affects total cost. Two, the public perception of nuclear being scary and an invisible killer inhibits adoption. Just look at Germany’s knee jerk reaction to Fukushima to see that in action.

>Where nuclear fails…

Nuclear fails because the public is uncomfortable with these plants, not for any technical or cost reason. Though to your point you could avoid spending the R&D on safety technologies and instead spend it on marketing which would likely yield better results.

Come on, the classical nuclear power plant is highly expensive to build and decommission. If the problem was purely public perception, we could have hundreds of plants far away in deserted places and transport the power on power lines. In reality, many nuclear constructions stalled or were stopped when cheaper alternatives became viable.

I think the Yucca mountain debacle is enough evidence to show that putting nuclear facilities, granted not generation, “in the middle of nowhere” is not a panacea.

It’s a third rail after Chernobyl and 3 Mile Island, the public perceives it as far too risky to allow anywhere near them. No one wants to touch the idea and yes, it doesn’t help matters that nuclear is insanely expensive.

You have that totally backwards. Nuclear has failed because the people building the plants have consistently blown through their cost estimates. Like Lucy pulling the football away from Charlie Brown, at some point they have to be held responsible for this.

Solar panels can't kill. You could have a very large field of panels, 0 deaths.

People falling off roofs while installing or maintaining panels is the biggest contributor to deaths from solar electricity. Per TwH, current solar is far from the safest: https://www.nextbigfuture.com/2008/03/deaths-per-twh-for-all...

That chart strangely leaves off grid scale solar? I wonder what explains that mysterious oversight?

And of course if you fit the panels at the same time as building the house you don't get any additional deaths and even rooftop solar sails to the top of the list.

I'm sure we'll find another obscure stat to focus on though (even if we have to leave off anything that beats nuclear). Dont let the facts get in the way of a good story.

Rooftop solar is a small fraction of solar installed worldwide, those stats are incomplete without also listing solar farms.

Yeah, agreed entirely. It's not the best document. But "solar panels never killed anyone" just turns out to be not true is all. It turns out everything has risks. I find post-construction rooftop solar to be a perfectly acceptable risk, personally. Grid-scale solar not on rooftops is even better.

What about the carbon footprint from the manufacturing and materials for the solar panels?

It's weird you think that use of fossil fuels is inherent in the production of solar panels, and cannot be substituted for.

I like nuclear but the death numbers are not as relevant when exposure time to radiation is the relevant factor and we've abandoned many cities to prevent those types of deaths.

> Where nuclear fails, and where improvement is desperately needed, is ability to deliver on budget and within schedule

The onerous safety regulations are mostly the reason nuclear plants run over budget and schedule. Safety improvements that can relieve some or all of that burde arr probably worth it to scale nuclear.

That's a big reason for why it got so expensive though :)

You could probably remove quite a lot of requirements and still have the safest energy generator and that would bring down the cost.

It is misleading to claim current generation plants are safe, for all relevant meanings of safe. If they were actually safer than other power sources, the plants would be insurable. You could call them safe if they did not pose a bomb proliferation risk. You could call them safe if cleanup after accidents was a well-understood and feasible process. You could call them safe if the risks did not reach to somewhere between hundreds of miles and the entire planet.

Safer nuclear power is not just about reducing the possibility of immediate death, which, of course can't be entirely eliminated. You still have risk to employees from non-radiological parts of a power plant.

What you won't have from safer nuclear power plants is the risk of spreading stuff like Strontium 90 over a wide area. That by itself is a very valuable goal that will vastly reduce the maximum downside risk and the cost of mitigating that risk.

Cost is part of risk, in the form of financial risk. Smaller, less expensive plants are less likely to become white elephants on rate payers' bills. They won't lead to To Big To Fail entities that may need bailing out because they are the custodians of a big nuclear mess.

Safety is multi-dimensional. People opposed to building more nuclear plants with current technology understand that. They want to keep their wallets safe AND their milk safe. They want to keep the value of their property safe. That's perfectly rational.

Safe is measuring how many deaths per user various power generations sources cause. Coal etc is less safe then nuclear because it causes more deaths. Yes when a nuclear accident happens, it can be bad, but that doesn't happen that often at all. Compared to the numerous accidents and deaths that happen every day with say coal. Also coal is outputting pollutants into the atmosphere which causes more deaths (a slower death but dead is dead). Cleaning up that air is also just as difficult as cleaning up nuclear waste.

> Safe is measuring how many deaths per user various power generations sources cause.

No. Safety depends not only on deaths but on all kinds of damage. It also does not depend on how many people nuclear kills per year. That number is predictable so it isn't even a risk (to society), it's a cost.

Nuclear is unsafe because of the damage it causes in the worst case. What happens when NPPs are operating correctly isn't even relevant to the discussion.

Is it possible to design a nuclear reactor that’s resistant to widespread corruption and incompetence?

In 2019, we have to consider that even advanced democracies with great scientists and technologists might descend into some form of illiberal rule. Imagine if you could not depend on leaders to shut down a plant if problems are discovered, or if contracts were awarded based on cronyism, or if it was impossible to guarantee the quality of materials, or if whistleblowers were not protected.

I'm not sure anyone can guarantee that any country will definitely remain stable over the lifetime of a nuclear reactor. Black Swans are out there.

I think the issue is that nuclear reactors, because of the economic scale, are not resistant to small scale corruption and incompetence. (See Fukishima.)

This is the number one thing that nuclear power advocates seem to ignore.

A lot of the modern molten salt thermal neutron designs are pretty much idiot proof. Aside from trying to breach the reactor vessel intentionally there isn't going to be a meltdown like pressurized designs. These are reactors that when they fail just kinda stop working.

There isn't any need for active cooling since the nuclear reaction is thermally regulated. There isn't any pressurized water that can blow the top off a containment vessel. Even if there is a breach it doesn't blow waste across the countryside because there is no pressure difference between inside and outside the reactor.

There are reactor designs that can't be used to make weapons, and when they fail, passive systems prevent meltdown.

Not that I'm aware of. All reactors, bar none, require safeguards to prevent the owner from making weapons-usable material on the sly. Civilian nuclear is a fairly impractical and round-about way to get weapons material (just use centrifuges... way easier), but if you think it's easier to get a nuke than a centrifuge, or if you are a corrupt leader who takes over a country that has nukes, you can generally make some pretty good U-233 or Pu-239 with any nuclear reactor. Yes, even Thorium reactors (they're the ones that make U-233).

China, India, USA, Russia, France, UK, Pakistan, and Israel already have nuclear weapons. If you look at the fraction of world energy that that set of countries and their collective military allies uses (nevermind Israel), you can feel pretty good about transitioning more to nuclear even given a non-zero risk of proliferation.

Thorium reactors can’t make weapons grade material. It’s just not part of the process.

Thorium is also more abundant and easier to work with. The only reason why we have an uranium/plutonium nuclear industry is because those fuels permit dual-purpose (weapons generating) designs. Now it is just industrial* inertia.

Edit: *industrial and regulatory.

Incorrect. Thorium reactors work by putting Th-232 into a neutron field, where it doesn't fission, but rather it absorbs neutrons to become unstable Th-233, which beta-decays into Pa-233 with a half-life of 21 minutes. Then Pa-233 in turn beta-decays to Uranium-233 with a half-life of 26.8 days. U-233 is fissile nuclear fuel, so when a neutron hits it, it will fission and release nuclear energy. All thorium-fueled reactors use this chain of events.

But there's a problem. Pa-233 is a strong parasitic neutron absorber. So when it's sitting there for 26.8 days, if it were still in the nuclear core it would poison the chain reaction. So what people plan to do is to pull it out of the core chemically and put it into a holding cell outside the neutron flux where it can decay to U-233 in peace. Then the U-233 is added back to the core as it arrives.

The U-233 is a potent nuclear weapons material and can be extracted from the decay tank in what are called in the non-proliferation industry "Significant Quantities". Faced with this issue, the ORNL folks created the Denatured MSR project in the death throes of the MSBR program (~1960s) which had U-238 mixed in to denature the WG U-233. Of course, then they were producing plutonium...

The general claim is that U-232 is also produced in trace quantities, which has Tl-208 way down its decay chain, which emits a massive 2.6 MeV gamma ray that's hard to shield. Since it's way down the decay chain and U-232 has a 69 year half-life, every time you chemically purify your uranium you have pretty small amounts of gamma emitters. So you can purify, assemble a weapon, and drop it in a few weeks without worrying too much about Tl-208.

The thorium-cant-make-bombs thing is a total myth. All nuclear reactors need safeguards, even thorium-fueled ones. This is doable and should not prevent us from making more carbon-free energy with any kind of nuclear reactor.

More abundant: meh, not really. There's uranium dissolved in seawater in vast, practically infinite quantities.

Easier to work with: definitely not. Higher melting temperatures for ceramics make solid-fuel thorium harder to fab, and the fluid fuel stuff is int he R&D stage. It also leads to lower-density fuels, which are crappier neutronically.

I’m not aware of any practical nuclear weapon design using U-233. Can you cite one? The tests I’m aware of appear to be inconclusive as to whether U-233 works as weapons material. They seem to have resulted in a fissle or very low yield device, have significant purification problems, and were dropped as a research pathway by all nuclear powers that worked with it.

Yes: The classic uranium gun-type weapon design works beautifully with U-233. Very low spontaneous fission, very excellent neutronics.

U-233 is unequivocally excellent weapons material. That's undebated fundamental nuclear physics. A Significant Quantity of U-233 is defined as 8 kg, better than U-235! [1] The folks down at Los Alamos aren't messing around.

[1] https://permalink.lanl.gov/object/tr?what=info:lanl-repo/lar...

Just read this: http://fissilematerials.org/library/sgs09kang.pdf

If things descend to that, you have bigger issues than the possibility of a nuclear accident.

A long time ago, as part of a "Industry Study Visits"-course at university, we went to visit Asea-Atom and were told about the "PIUS" reactor ("Process Inherent Ultimate Safety"). Supposedly the construction was "passively safe" (i.e., breakdown of cooling pumps etc would not matter.) The idea was to have the reactor encased in an open pipe contained in a larger (closed) tank with borated water. Using stable stratification, the non-borated water was more or less kept contained in the inner pipe using density locks; if something would go wrong the borated water would get sucked in and and shut the reactor down.

The engineers were very optimistic about selling this even as small municipal thermal power plants (for heating water) very close to city centers. The idea of passive safety is quite beatiful, but it seems no PIUS reactors were produced. Rosatom seems to have had some success.

More info about PIUS can be found at



I think the issue with safe reactor designs is economic and regulatory / political, instead of intentional.

Nuclear power was invented. A few nuclear accidents happen. The solution was to put more regulation in place. Regulation increases costs and limits reactor designs (large plants, conservative / pre-existing design).

End result? It's impossible to build "safer" reactors, because they're economically uncompetitive under the regulatory burden designed for older reactors. And the regulations never change because no one builds anything but old-style reactors.

I understand the DoE and other similar organizations have prototype programs, but from results evaluation they seem to have gaps in the path to production.

Essentially, we're letting 1960s nuclear fear of 1960s reactor designs write our regulations instead of science.

The tail risk on nuclear is so bad that innovation which merely reduces the cost of energy isn't nearly compelling enough. Energy costs (either direct, or indirect via carbon taxes or other pricing in of externalities of burning stuff) need to rise significantly before there will be a real driver in the system.

If you want nuclear, you want punitive carbon taxes, or carbon trading with low caps.

> If you want nuclear, you want punitive carbon taxes

I think this is the crux of the issue. Carbon-emitting plants get a free pass on safety and long-term environmental costs, while for nuclear all those things are examined with a fine-tooth comb, then compared to the cost of alternatives without those things.

In any regulatory regime that punished carbon emission the same way it did nuclear waste, nuclear contamination, etc, then coal plants would be unthinkable.

I was going to say "then nuclear would be obvious", but I'll hold judgement there because I don't know how that would compare to other non-carbon-emitting sources (hydro, solar, etc).

Carbon-emitting plants are safe. They cause a predictable number of deaths every year. That's a cost, similar to the environmental costs.

That doesn't mean they are less bad than nuclear plants but the claim that they are unsafe is just wrong.

I'm not in the field, but it seems like the risk calculation itself could be used as a driver.

By shifting the regulatory cost from focusing on lesser risks to catastrophic ones, you could make fundamentally safer reactor designs economically competitive while still retaining the primary political goals (avoidance of major event).

I'm concerned but not running around screaming if a reactor leaks tritium. I'm very much the latter if a reactor goes prompt critical.

It's my understanding governments have considered light-touch regulation of nuclear safety with the policy "any nuclear power plant that can get insurance to cover a $100 billion+ meltdown cost can be built" and the result is nobody can provide such insurance, so no plants get built.

From an actuarial standpoint, I wouldn't go near nuclear with a 10' pole either. Simply because the population size is too small.

In the same way I wouldn't offer SR-71 insurance.

That feels like a dodge on the part of regulators.

There's an actual actuarial analysis online somewhere, though I can't remember if it's in German, and the problem is not population size, but a nearly unbounded risk. Take a look at Fukushima and think about what would have happened in terms of cost had the wind blown in another direction.

Maybe this?


Thanks for the pointer! Will be an interesting read.

The president of Exelon has stated that for new nuclear to compete with natural gas combined cycle plants in the US, the CO2 tax would have to be in the range of $300-400/tonne. This is very high, and many cheaper alternatives would become available first at lower values of that tax rate.

The political will to force through long term waste storage is also missing: https://en.wikipedia.org/wiki/Yucca_Mountain_nuclear_waste_r...

This is fairly cheap, a few hundred million, and in terms of safety it's a no brainer, because the US already has nuclear waste that needs long-term storage.

If this can't be solved, it seems almost pointless to dream of new reactors.

Why solve it? Spent fuel can be stored on the surface, safely and cheaply, in dry casks. And stored on the surface the decay heat dissipates into the atmosphere, rather than building up underground.

I have to wonder why burial was being pushed so hard, so early. Maybe they were worried surface repositories would be targets for ground burst nukes in WW3?

Agree. The only thing I see changing this is possibly reactors developed in another country that solve some of the fundamental problems, and becoming successful there. China comes to mind, but there's so little transparency its hard to tell whats real there.

The Chinese are doing something vaguely similar, the DHR-400, which is a low-pressure pool-type reactor for district heating. https://en.wikipedia.org/wiki/China_National_Nuclear_Corpora...

The usual problem is not shutting down the reactor: both TMI and Fukushima was properly shutdown. Important task is cooling down the core (and SFP) after that.

Left on its own, halted thermal reactor generates hundreds MW of heat after shutdown. That heat destroys cladding of fuel, generates explosive Hydrogen and causes meltdowns of former core.

It is believed that ATF, core catchers and electricity-independent passive cooling will reduce risk of this types of incidents, commonly called LOCA - Loss of coolant

Fukishima unit 1 had an Isolation Condenser, which is the sort of passive safety system you're talking about. It required no electricity, merely that some valves be open. Supposedly after the earthquake and before the tsunami, the operators opted to close at least one of those valves for reasons that are a little hazy, but might have had something to do with not cooling the reactor too fast. After the tsunami, they couldn't electrically control the valves, and for some reason there was ambiguity about the state of the valves, and no one went to physically check them and open them until it was too late and the fuel had melted.

Sounds a bit like a Pythagorean cup, just with the liquid overflowing the “lip” due to heat rather than volume.

If Nuclear power becomes a viable safe and clean energy, how are we going to deal with countries that don't have nuclear technology?


There are only 31 nations in the world that has nuclear power.

If, in the unlikely case, we successfully distribute the nuclear technology to the rest of the world. How do we prevent/contain states go rogue and start enriching fuels for nuclear bomb?

This might be a harder problem to solve than technology break through.

> How do we prevent/contain states go rogue ...

By using different fuels. The fuel we currently use (enriched uranium) was chosen because we could also use it to build weapons. A different fuel (i.e. thorium, etc) could be used that couldn't be used in making weapons.

I didn't know that! Thanks for sharing! I am not familiar with nuclear technology and I do have a question: Is the technology used to make Thorium power plant very similar to that of making Uranium rode?

This question aside, I feel states can not resist the temptation to get nuclear bomb technology: It's a great equalizer for power. Looking at how North Korea was able to repeatedly get U.S to the bargaining table, I think none of the nuclear powered country would want any other country on Earth to gain such technology.

Excellent point; using money for development and installation of much safer renewables is a much better option for export to less rich countries.

"Safer Nuclear Reactors Are on the Way" this kind of headline pops up every few years. Too bad it takes a decade to build these things, they cost billions, they produce harmful waste that persists for thousands of years, and in failure cases produce exclusion zones for thousands of years. Effort and investment would be better spent on solar and wind power projects.

Fossil fuels already kill millions. According to Stewart Brand, the nuclear waste for one’s entire life would fit into a can of soda. And despite nimbyism, there’s already a solution for the waste in the US: Yucca Mountain.

Oh, and it doesn’t produce the greenhouse gases that are currently threatening global stability in a timeframe of decades.

We shouldn’t minimize a technology’s shortcomings, but we should at least frame it fairly and soberly among our set of options.

Yucca Mountain was never built and the project defunded in 2011.

"Too cheap to meter" - my ass

That's fusion not fission apparently: https://en.wikipedia.org/wiki/Too_cheap_to_meter

There's is no good evidence that phrase was about fusion.


Cheers. (Oh Wikipedia! You led me astray!)

* Safer Nuclear Reactor Designs Are on the Way

Whether actual reactors get built is another matter.

The article is talking about new fuel rods that would work in existing reactors. So, your suggestion change to the title would be wrong.

> Manufacturers are also experimenting with “fourth generation” models that use liquid sodium or molten salt instead of water to transfer heat from fission, removing the possibility of dangerous hydrogen production.

Yup. One of those few areas where the capital required is so massive it can bankrupt even big dogs if they fuck up. See Westinghouse. Need some more gov joint investment or it will be the same state in 20 years as it is now.

I've always wondered: why isn't it possible to make tiny, safe, low-cost reactors? Do reactors really always have to be so big and expensive?

Human factors.

It's easier to secure a massive plant than a thousand small ones.

Imagine the outcome of some underpaid and overworked cable runner digging into a buried mini-reactor with a JCB digger. Or a trucker falls asleep at the wheel and drives their Mack truck through an above-ground reactor.

The difference is between the media coverage being "Idiot drives truck into nuclear facility, is arrested, no damage" and "Idiot digs into mini-reactor, irradiates neighbourhood".

And that's before people start yelling "Not in my back yard!"

There are already thousands of medical and industrial sites which contain material arguably scarier and more susceptible to accidents than what would be in a small reactor. The most recent was several months ago at UW Harborview: https://www.kiro7.com/news/local/hazmat-response-for-radioac...

I think your last reasons are probably more influential. Nobody knows or seems to care much about sites like where the above incident occurred. And so far such incidents have been fairly contained, at least in the U.S. In some other parts of the world neighborhoods do become contaminated on rare occasion.

Reactors can be small and (relatively) cheap, but those aren't cost effective for power production. Producing power for sale on the grid requires huge economies of scale to compete with other sources.

Tiny, safe, low-cost reactors are a better fit for off-grid power and heat in remote areas.

Because the licensing cost is the same per reactor, regardless of its power.

That's supposed to be the promise / fix of SMR: plop down a fully self-contained reactor of a few tens~hundreds MWe in a shaft, plug it to the grid and leave it there for a few decades, when it's out of fuel swap it out and go recycle it in a dedicated facility.

Though of course aside from not quite existing yet and probably needing a smart grid to coordinate properly these will take full-bore hits from NIMBY.

The predominant NIMBY strategy is to request a new impact study every 6 months so as to insert delays and restarts into the capital-intensive, highly coordinated construction process, bringing it from merely arduous to nearly impossible. Pre-fabbed reactors would reduce both the attack surface and the per-hit damage considerably.

Where has that happened?

There are plenty of sites that would be happy to host nuclear, if it were possible to build. Vogtle and Summer are our recent examples, and NuScale is deploying soon too.

NIMBYs have not held back nuclear as much as the industry itself.

The nuclear power plant at Shoreham on Long Island is possibly the most famous example of NIMBYism killing nuclear. The reactor was built and operated at test levels, but the NIMBYs demanded for full operation to include a disaster plan to evacuate all of Long Island (5+ million people) in a completely impossible time span of a few hours.

> That's supposed to be the promise / fix of SMR

I'm surprised the (US) military isn't looking into these more.

I would think it would reduce /simplify the logistics of hauling diesel for generators over hell's half-acre.

A nuclear reactor in a battle zone is a dirty bomb sitting in your territory.

They did. https://en.m.wikipedia.org/wiki/Army_Nuclear_Power_Program

One issue was that small-package reactor designs of the 50s and 60s required highly enriched uranium... which doesn't seem like the best idea to leave lying around at (by definition) remote outposts.

Yep a simple WOG value you can buy for $9 dollars at home depot costs $500 dollars after it is certified and tested and approved for use in a plant.

My understanding from a friend who worked on nuclear subs was that transmutation due to radiation is what makes working with reactors so complicated and error prone. You can't assume anything about common tools and materials since the metallurgy becomes quite important in ways that we're not used to.

Well, tools better not be exposed to much neutron radiation, or else the person holding the tools will be in trouble. :)

What he may have been talking about is activation of troublesome elements that cause contamination that interferes with access. A prime example of this is the wear resistant alloy Stellite, used in valve seats. It's an alloy of cobalt. Some cobalt does wear off, gets circulated through the reactor, and is transmuted to 60Co, which increases the radiation field around all the piping.

All the materials in your reactor that are exposed to neutrons need to be purged of troublesome trace elements that can cause this sort of activation.

So do aircraft parts. It's easy to find $400 screws, for instance, for aircraft.

It has to do with strict traceability, design validation, and testing-proven performance more than it does anything about nuclear aspects.

Doesn't SpaceX sidestep a bunch of this stuff by achieving reliability via redundancy instead? Like, put three valves in series when it needs to fail closed, and three in parallel when it need to fail open, that kind of thing.

I wonder if there's potential for a similar approach here?

A rocket total failure has a more obvious, bounded cost that's lower than a reactor failure.

PBS/NOVA ran a documentary a couple of years ago talking about safer nuclear reactor designs. This included lessons learned from Fukushima.


Just finished this. The end gives me more hope in nuclear reactors. Thanks!

There is also ongoing work on LFTR reactors https://en.m.wikipedia.org/wiki/Liquid_fluoride_thorium_reac... which are much simpler and safer than reactors using solid uranium, because they have only fraction of fuel of solid reactors, do not have any pressurised containers, and have stable rate of reaction.

Two experimental reactors of this type have worked in 60s, but technology was abandoned because it didn't produce the isotope of plutonium used in nuclear weapons.

The "doesn't make bombs" story of the molten salt reactor program's cancellation is largely a myth, albeit one that's extremely common on the internet [1].

Fluid fueled reactors, mostly in the form of Molten Salt Reactors (MSRs), of which the LFTR is one brand name of, do have lots of potentially huge benefits in terms of simplicity, online refueling, and straightforward reactivity effects. We do only have about 5 reactor-years of experience with them, and so we don't fully understand the costs of building, operating, and maintaining such systems in today's regulator regimes.

There is some reason to be concerned. When the fuel is dissolved in fluid, the radioactive fission products are dispersed everywhere. Literally half the periodic table of the elements is in there, and lots of it is volatile and mobile. It gets on your pumps, your valves, your heat exchangers, etc. Doing routine maintenance becomes very challenging and will need to be done remotely.

A line I heard recently regarding MSR maintenance is: "You'll need robots to do the maintenance of your maintenance robots." Another memorable gem is "If you can make robots that can do that, you should just sell the robots"

We should absolutely work on progressing this technology, but in the face of a climate disaster, we should just build more of what we know is already safer than almost every kind of energy system we can deploy, which is regular Gen III LWRs. We need to solve problems on the construction yard so we can build them much more cheaply.

[1] https://whatisnuclear.com/thorium-myths.html#myth1

Good points.

How do some of the other alternatives like Pebble Bed fit into this?

I imagine PBRs would be more challenging to recycle fuel as it's combined with the moderator(?), but are there other issues which make it unrealistic compared to traditional PWR/BWR/LWR/Magnox reactors?

I'm starting to really like gas-cooled reactors like pebble-bed. They have two fundamental technical challenges. First is that gas coolant (typically helium) isn't a great heat-transfer mechanism so you need to spread your heat generation out in a large volume. This low power density results in pretty large structures (which can get pricey to build) for relatively low power, compared to other coolant configurations like water and especially liquid metal. Related, if there's a coolant leak, all the pressurized gas shoots out and you need backup cooling systems or particularly low power density that supports heat removal via conduction and thermal radiation. This can ding your economics pretty bad too.

Second, the fuel particles you mention are very expensive to fabricate, $10k/kg. Estimates of future costs go "as low as" $3k/kg, but some say it could even go up to $30k/kg. In all cases, that's really expensive fuel fabrication. There's a plant in China that can fabricate them in moderate bulk right now, so perhaps with time and experience we can figure out how to bring this process down in cost.

Aimed at solving power density and decay-heat cooling issues, there's also the salt-cooled version of the pebble bed reactor which gets the high-temperature fuel benefits and trades high-pressure gas for low-pressure salt. A research group from MIT and UC Berkeley has worked on this for years under Prof Charles Forsberg, and a company in the Bay Area called Kairos is now working on commercializing it. Unfortunately you get a lot of tritium production from the best known salt, which is a FLiBe salt, where the Lithium + neutrons results in crap-tons of supermobile tritium. You can cold-trap most of it but it's still a pain. And the fuel is still $10k/kg to fabricate as far as anyone knows, and the graphite cracks, and high temperature corrosion under irradiation is hard.

FLiBe also needs Be. World annual production of Be is 230 tonnes. And new Li isotope separation facilities would be needed, as only very small amounts of 6Li could be tolerated. The existing technology for that is not workable now due to mercury leakage.

RE: A line I heard recently regarding MSR maintenance is: "You'll need robots to do the maintenance of your maintenance robots." Another memorable gem is "If you can make robots that can do that, you should just sell the robots"

Maintenance of MSRE was done by humans without much downtime or exposure[1]. Ease of maintenance is a function of design. Just design it carefully.

[1] https://energyfromthorium.com/pdf/NAT_MSREexperience.pdf

MSRE had fans blowing on pipes as cooling. It had no real fluid-to-fluid heat exchanger or power conversion cycle, which is where lots of maintenance troubles arise from. Furthermore, they were in the 1960s, before the NRC existed and before we worried about ALARA. Furthermore, MSRE cannot to this day account for about half of their radioiodine inventory. Furthermore, Alvin Weinberg himself says in his 1990s autobiography, The First Nuclear Era (amazing read btw) that they were just piping radioactive gas into the forest nearby back then (or, wait, was that the aqueous homogeneous reactor? I forget, I left all my copies of that book at the office...).

A lot has changed since MSRE ran, and MSRE was a fairly simple experiment to prove a concept. It didn't have all the systems necessary to make practical energy, and so it didn't have the maintenance issues you'd expect. Also, it only ran for like 5 years, vs the 60-80 we're hoping for these days from these facilities (inherently requires lots of maintenance).

Have you ever done work planning for ALARA at a light water reactor? Those who have raise eyebrows really high when academic reactor designers start saying how easy the maintenance will be. Admiral Rickover's quotes from 1953 just keep on coming back to haunt us [1]. He didn't curse us to death, but he sure warned us that we need to be working really hard on new/effective solutions to these kinds of problems. Most advanced nuclear advocates skip over these points.

RE: Design it carefully: This takes practical experience. The number of people today designing new reactors who have this kind of experience is very close to zero. We will have to re-learn.

[1] https://en.wikiquote.org/wiki/Hyman_G._Rickover#Paper_Reacto...

RE: Furthermore, they were in the 1960s, before the NRC existed and before we worried about ALARA.

"Exposure of personnel to radiation has been held well below permissible limits: the maximum exposure of any individual in any quarter has been <0.5 rem." This is within the ALARA standards.


RE: no real fluid-to-fluid heat exchanger.

MSRE had salt-to-salt and salt-to-air heat exchangers made from hastelloy-N. https://www.flickr.com/photos/oakridgelab/31537153147/

RE: or power conversion cycle, which is where lots of maintenance troubles arise from.

That's the part which is not highly radioactive. Fluid fuel reactors have simplest fuelling mechanism of any reactors. The fuelling of a fluid-fuel reactor is even simpler than fuel injectors of diesel engine. Where the need for "maintanence" arise in this simple machine??

Only moving parts are the pump impellers and the control rods. ORNL had some difficulty designing the bearing, seals etc. for the salt pump. But, even that is solved today with concentrating-solar salt pumps.

> Exposure of personnel to radiation has been held well below permissible limits

Ah, the good old days! 25-50% of the radioiodine from MSRE is completely unaccounted for. No one knows where it went. This is wholly unacceptable from a modern regulatory approach. It will have to be found.


> MSRE had salt-to-salt and salt-to-air heat exchangers made from hastelloy-N

Fair enough. It's generally in the salt-to-water heat exchanger where major maintenance concerns take place in a power reactor. Check out steam generator problems in PWRs and SFRs to see what I mean. You're right that the radiation will be low there if they use an intermediate salt. But the baseline maintenance problems come in at the steam generator in most plants. So MSRE avoided any problems there but any power MSR will have them like any other reactor. Good old BWRs get around this via direct cycle.

> Where the need for "maintanence" arise in this simple machine??

Pumps. Heat Exchangers. Valves. Flanges. Welds. Vessels. Graphite. Reflectors. Fission product processing equipment. Instruments/sensors. Control mechanisms. There are very complex systems with lots of things working together in a very tough environment (high radiation, high temperature). Maintenance is a major challenge.

RE: Ah, the good old days!

<0.5 rem per quarter (or 5 mSV) is in compliance with today's dose limit. ORNL was a competent American national lab with high standards even back in the 1960s. Another hollow argument from today's incompetent nuclear industry.

"Exposure of personnel to radiation has been held well below permissible limits: the maximum exposure of any individual in any quarter has been <0.5 rem." http://moltensalt.org/references/static/downloads/pdf/NAT_MS...

"The maximum annual dose allowed for radiation workers is 20 mSv/yr" https://www.world-nuclear.org/information-library/safety-and...

The radioactive gas was probably noble gases like krypton and xenon. They'd have to be careful with the xenon, as 137Xe decays to dangerous 137Cs (halflife 3.8 minutes). The idea "all the radioactivity stays in the salt" can be wrong, as that xenon could deposit the cesium outside the salt if it bubbles out quickly enough.

135Xe also can be removed (halflife ~9.2 hours). It is famously a very powerful neutron poison with important effects on reactor operation; those advocating thermal breeders count on it being removed before it soaks up neutrons. But this leads to an increase in production of its decay product, 135Cs, which has a halflife of 2.3 million years.

MSRE had a charcoal-bed off-gas system which safely stored all the noble gases. It was cooled and shielded with water, similar to today's PWRs. PWRs also have water chemistry control and resin-bed filters for primary loop which is highly radioactive and shielded. Construction of the off-gas system is described in pages 58-60 in ORNL-3708: Molten-Salt Reactor Program: Semiannual Progress Report for the Period Ending July 31, 1964 https://energyfromthorium.com/pdf/ORNL-3708.pdf

Thanks for the link, it's hard to find balanced stuff on thorium MSRs.

A big part of the Fukushima disaster were not the reactors but the spent fuel tanks. Their existence there and close to many reactors is testament to the still unsolved challenges of storing the waste.

Until we can find a safe and permanent way to store spent fuel (or otherwise render harmless fission products with long half-lives), nuclear power is always going to fail the "Facebook mom test". And, in my opinion, rightly so.

This has been solved on a theoretical level for a long time. All it needs is financing and political will to build the storage facilities.

Despite a long-standing agreement among many experts that geological disposal can be safe, technologically feasible and environmentally sound, a large part of the general public in many countries remains skeptical. from: https://en.wikipedia.org/wiki/Deep_geological_repository#Pri...

Right, but it currently has neither, so the problem is for all practical purposes still unsolved.

In fact, not only are the dozens of needed DGRs not being built, in many cases fuel which has cooled enough to be moved into cask storage is instead still sitting in actively cooled pools. So not only have we not built any large DGRs (other than that under construction one in Finland), we haven't even taken the intermediate step of preparing spent fuel for any form of passive storage.

> Breeding fuel cycles attracted renewed interest because of their potential to reduce actinide wastes, particularly plutonium and minor actinides.[12] Since breeder reactors on a closed fuel cycle would use nearly all of the actinides fed into them as fuel, their fuel requirements would be reduced by a factor of about 100. The volume of waste they generate would be reduced by a factor of about 100 as well.

rightly so? the problem you and facebook mom's aren't grasping is that the shit we're doing with fossil fuels is far more destructive and deadly that rotting containers of nuclear waste.

This is an important topic but given that the absolute emergency at the moment is to reduce our carbon footprint I think that handling radioactive waste is a lesser evil. Most of us spend our days in cities, breathing toxic fumes from cars and factories, yet many of us draw a red line at any kind of radioactive risk, no matter how small. For me this is the equivalent of people who are afraid to fly in airplanes but drive their kids to school every day. It's understandable but obviously not very rational. An airplane crash makes the news for days, sometimes even months. A guy crashing his car in a ditch barely registers. Obviously one of these things is massively more common than the other however.

Look at Germany quitting on nuclear and using coal power plants instead. Look at France producing relatively cheap and low-carbon energy using mainly nuclear power plants: https://www.electricitymap.org/

This is one of these conversations like GMOs, like vaccines, like herbicides, like so many others where it seems that rational conversation is impossible because only extreme viewpoints can be heard. Nuclear is incredibly dangerous when it goes wrong but the risk can be managed and when it works well it's very competitive. Of course the costs of properly dismantling the reactors and storing all the radioactive waste needs to be factored in. It's a tough engineering problem but compared to rising sea level and massive perturbations in the climate it seems a whole lot easier to manage.

I'd much sooner live close to a nuclear power plant than next to a busy highway.

You don't store spent fuel. You reprocess it, getting out new fuel and a much smaller amount of waste that is much less hazardous and only needs to be stored for a much shorter time.

With seawater uranium extraction getting cheaper by the year and reprocessing still looking like it has all the high costs of remote operation plus perceptions of proliferation risk, and with nuclear not ramping up very quickly due to cheap fracked natural gas that's starting to get exported from the US in bulk, I don't think there's a great reason to reprocess at the moment.

Deep geological waste repositories are fine. Lets get those operating safely so we can answer the "what do you do with the waste" problem definitively and then move on. Reprocessing may make sense again sometime in the future but for now we need the prereq of deep storage. I agree with Frank von Hippel in this case [1].

[1] http://npolicy.org/userfiles/image/The%20Costs%20and%20Benef...

> I don't think there's a great reason to reprocess at the moment.

At the moment, no. But the economics are likely to change over the next century or so. Which means that reprocessing should definitely be taken into account when determining how long spent fuel needs to be stored. Requiring storage facilities to be good for ten thousand years or more is not reasonable given that it will be economical to reprocess it long, long before then.

With the cost of seawater uranium extraction getting so low I'm really not convinced reprocessing will ever become economical. Doing process stuff at scale in hot cells with remote handling equipment is expensive. Melting down solid fuel into vats makes fission products harder to inventory and track. It's just a pain.

Check out all this seawater extraction progress [1].

[1] https://www.pnnl.gov/news/release.aspx?id=4271

you claim "with cost ... getting so low"

however, neither your link nor anything from a reputable site that i've found through google says anything about costs or current industrial production. do you have any data to back up your claim of low cost, or is that claim purely speculation on your part ?

unless there's data that i've missed, it doesn't sound like seawater extraction is currently economically viable

There is no industrial production; it's in the R&D stage. Current costs are estimated at about 6x uranium mining. Thus, it is not currently economically viable. With R&D, costs are expected to go down. If we go in on nuclear long term, uranium shortages in a few thousand years will make uranium more expensive.

We're comparing long term scenarios here: reprocessing vs. seawater extraction. The reprocessing + hot refabrication process has been done and is extraordinarily expensive. If seawater extraction at scale is indeed viable, it's long term prospects in my view are way better than reprocessing.


Can't you just drag the waste out of long-term storage if you so decide?

Yes, certainly. That's why "long-term" doesn't have to mean "for ten thousand years or more". It only has to mean "until we decide to drag it out again because it's now economical to reprocess it".

how much weight is it? with cheaper launch costs could we get it out of Earth orbit fo less?

The risk of a launch failure causing highly radioactive stuff to rain down on the surface of the earth is just WAY WAY bigger than the risk of some leak in a geological repository in 100k years (when practically all of the truly nasty stuff has long decayed away).

90,000 metric tonnes in the US of high-level waste (incredibly low given that it's produced ~20% of our electricity carbon free for 40 years). You'd have to also launch a bunch of heavy shielding with that just for handling purposes, so be conservative and multiply by 10.

You'd need a really reliable launch process like a space elevator to do this without worrying about dispersing it around in the atmosphere. It's worth talking about but it's hard to imagine a socially-acceptable pathway at the moment. Deep geologic repositories are safe and known. We should just use them.


1. No one does that, or has the ability to do that except the Russians [0] 2. Much less hazardous is still tons of extremely dangerous stuff that will last 100 k years. [1]

[0] fast breeders. I know you can re-process fuel for normal nuclear reactors. But that doesn’t give you: “less hazardous and only needs to be stored for a much shorter time” waste

[1] to a first approximation linger lived isotopes are less dangerous. But the conclusion that they’re not a problem is not correct:

- An isotope that lives 100k years is incredibly radioactive! - these isotopes can produce children that are very short lived, and therefore nasty (think short lived radon, produced from geologically decaying isotopes)

Edit: spelling of “extremely”

>...I know you can re-process fuel for normal nuclear reactors. But that doesn’t give you: “less hazardous and only needs to be stored for a much shorter time” waste

I am not very familiar with the Russian breeder design in particular, but generally that is wrong fro 4th generation designs:

"...Fast reactors can "burn" long lasting nuclear transuranic waste (TRU) waste components (actinides: reactor-grade plutonium and minor actinides), turning liabilities into assets. Another major waste component, fission products (FP), would stabilize at a lower level of radioactivity than the original natural uranium ore it was attained from in two to four centuries, rather than tens of thousands of years"



While there are issues with nuclear power, the worry people have about nuclear waste is greatly overblown to say the least. The amounts being generated are manageable and in a relatively short amount of time we can use most of this "waste" to generate electricity.

Breeder reactors are fast reactors. “Fast” refers to neutron energy that “Breeds” new fuel.

Yes, the west has done research and maybe a couple of demo reactors of insignificant power. But only the Soviets, and then the Russians have an industrial sized “fast”, or “breeder” reactor.

As to the waste of “breeders” being manageable, that remains to be seen, doesn’t it?

>...Yes, the west has done research and maybe a couple of demo reactors of insignificant power.

Granted that the power level for EBR II was insignificant compared to a commercial reactor, but it did run successfully for about 30 years and generated about 2 billion kilowatts of power.


>...As to the waste of “breeders” being manageable, that remains to be seen, doesn’t it?

Within about 4 centuries the small volume of waste generated by a breeder reactor should be less radioactive than the uranium ore that it came from.

False: France has [1].

Double digits of France's electricity comes from reprocessed nuclear fuel.

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

OP specifically referred to breeder reactors, which this is not. This is a reprocessing plant which “scrapes” fuel like Pu (which is not that radioactive) and puts it in a normal reactor.

The nasties are all there still.

Breeders “make” their own fuel from actual waste. The US and France had reader had breeder programs, but shut them down.

> fast breeders

How many would actually be needed to burn up the unused fuel of "regular" reactors? Is there some ration of regular:breeder that would be needed (5:1, 8:1, 13:1)?

> to a first approximation longer lived isotopes are less dangerous.

But isn't the shielding required for the longer lived stuff simpler? Presumably the short-lived stuff is hotter gamma radiation, which needs more shielding.

Cesium-137 for example has a 30-year half-life. So after e.g. 60 years you still have 1/4 of the radioactive cesium-137 remaining. For context, that's less than the length of time since the Three Mile Island accident.

Edit: according to Wikipedia, cesium-137 decays to barium-137m, which decays to barium-137 by gamma ray emission (https://en.m.wikipedia.org/wiki/Caesium-137). So even though cesium-137 decays through beta radiation it needs shielding against gamma radiation.

> How many would actually be needed to burn up the unused fuel of "regular" reactors? Is there some ration of regular:breeder that would be needed (5:1, 8:1, 13:1)?

Depends on the specifics, e.g. Russia is proposing a 2:1 ratio for a cycle they're planning:


I can agree to "noone does that" but 100 000 years nuclear waste is not true.

ALMR reactors would use that waste to produce short half-live waste which radiation can even stop in the matter of hours...

Thats what Chinese invest into now and technology is 40 years old.

Technologically we are way past the "dirty&dengerous" nuclear reactors. ALMR also fixes issue of old nuclear reactors that could be shut down overtime.

People fear the second Chernobyl.. thats that why we dont invest into Nuclear Power that is our only chance in current age. There is no logic in that, only mass media, lobbing and disinformation going rampant..

One reason would be that the ALMR uses liquid metal, and the onus is on the nuclear industry to convince us that liquid sodium isn’t a terrible idea.

‘S/sodium/whatever other metal you prefer/‘

I think multiple studies about the topic were enough to convince people in power, but screaming "CHERNOBYL" or "Nuclear Bombs" convinces an average voter way better..

It's a tragedy..

Why do only the Russians have the ability to reprocess these fuels?

They're the only nation with operating fast breeder reactors than can handle this type of waste.

Why are they the only ones operating this type of reactor?

Building new reactors is costly and you need public opinion to agree to that. Unfortunately when someone proposes building new kinds of reactors some asshole backed by "Oil Corp Co." runs ahead screaming "Chernobyl Fukushima!!!" and public opinion is instantly biased negatively to that idea.

Its completely illogical to block Nuclear Power advancement, but goverments are either lobbed or public opinion disagrees after being fed complete horseshit disinformation.

Fast breeder reactors that have been successfully run are difficult/costly and have proliferation concerns.

They’re, arguably, the only country left with a serious nuclear industry. One that can propose a new reactor design and follow up to commercialization.

The US’ got lazy, the European was good, but never innovative, Canada and S. Africa are too small.

The US didn't get lazy, the US allowed the market to speak (with substantial deregulation of the electrical power generation industry). And the market said nuclear is a loser technology, compared to alternatives. Not investing in loser technologies is not laziness, but intelligence.

> No one does that

Um, what? France has been reprocessing for decades.

> Much less hazardous is still tons of extremely dangerous stuff that will last 100 k years

Um, what? What's left over after reprocessing is only dangerous for 100 years or less.

OP separates reprocessing from breeding. His statement is clear that no one, except Russia, breeds.

100 years for reprocessed waste? Do cite!

> An isotope that lives 100k years is incredibly radioactive! - these isotopes can produce children that are very short lived

Oh really? Which isotope among the fission products would that be?

That would fall under OP's “otherwise render harmless” clause: there are proposals for managing this but currently at least the United States has a problem with waste being stored in places which weren't designed for it. Storage and reprocessing really needs to be demonstrated as a reliable working system before many people are going to be comfortable expanding capacity.

Additionally someone has to finally say "back off" to Oil Industry which is lobbing hard against any Nuclear Power advancements.. I think this is the biggest issue.

(ALMR tests performed in USA already confirmed what you asked for and that was 1984..)

> (ALMR tests performed in USA already confirmed what you asked for and that was 1984..)

So … where's it in production yet? The reasons why it hasn't happened might be instructive for learning why this problem is harder than it might seem.

China is currently building two such reactors. The reason why this technology has not spread is simple: "Energy would be too cheap. Oil industries would collapse, you can imagine how big of an impact that would have on other economy segments and how some of the richest ppl in the world would instantly lose influence on the goverments."

I look at it as a tragedy. Oil Industry is like a cancer to our society right now.

I'm sorry, but what you are saying there is ludicrous. If it would really make energy "too cheap to meter" then no conspiracy could keep it back -- the people making it would have plenty of excess cashflow to grease the palms of potentially interfering politicians.

The truth is more mundane (and you should have realized something was wrong when you started thinking in conspiracy theories). The technology is simply not as great as you think it is, and like most technologies it's probably not going to win. There's no dishonor in that; the market is a brutal place.

If we have to decide our policy based on "Facebook X test" we're f*cked.

That's kinda just how democracy works. The alternative is a non-representative Jeffersonian republic.

Supposedly, most western democracies are representative democracies, not direct democracies.

But we have.

You can just dump it into the ocean floor with little consequence.


Once it's down there it might be safe, but the devil is in the details. How do we get it there with 100% reliability? If you think an oil spill is bad, consider the effect of a spent nuclear fuel spill.

Nuclear waste is mostly solid and very dense.

Water absorbs almost all harmful radiation within a few meters

The thought process behind just throwing barrels into an ocean trench as was done by the US was and still is sound but people are freaked out by the notion. The UK was encasing barrels in concrete before doing the same which is more than good enough by most measures.

Ultimately nuclear waste is easier to deal with than some other toxic industrial waste or chemicals.

How do you spill a ceramic?! It's a heavy solid, not a liquid!

But then where would we get non-irradiated steel from? We're already harvesting it from old, pre-nuclear-era sunken ships: https://en.wikipedia.org/wiki/Low-background_steel

Irradiated steel comes from irradiated air used in the steel making process, all of which came from bombs detonated in the atmosphere.

Nuclear waste sitting at the bottom of the ocean will have a hard time ever reaching the atmosphere.

Like yucca mountain?

Who is going to pay for all this?

And wouldn't it be more efficient to spend the money on energy technology that has none of the problems and is carbon-neutral?

The potential for renewables in the US is fantastic. For solar alone a recent report states:

The total estimated annual technical potential in the United States for urban utility-scale PV is 2,232 terawatt-hours (TWh).

Full report at https://www.nrel.gov/docs/fy12osti/51946.pdf

Minor note: nuclear is carbon neutral too.

Secondary minor note: carbon neutral power sources (e.g. wind or solar) also have a carbon cost. It comes from building the damn thing and continuing to maintain it (e.g. new parts, setting up crane access...)

And building massive, complex nuclear reactors somehow doesn't incur tons of fossil fuel usage? How much carbon is associated with the years' worth of human activity and material supply chain to build a reactor? How about the ongoing maintenance and the carbon footprint of all of the specialized staff to maintain the safety of the reactor? How many scarce nuclear trained specialists must be flown around in fossil fueled planes to inspect reactors? How long does it take to break even, carbon debt wise? How does the carbon usage of the real world dependencies of nuclear measure up to the building and maintenance of solar panels and wind turbines? If you're going to make a minor note about renewables, it's only fair to make the same about nuclear.

> And building massive, complex nuclear reactors somehow doesn't incur tons of fossil fuel usage?

It involves significantly less.

Nuclear power generates significantly more energy for the amount of resources used.

Wind and solar have peaks and valleys of production, requiring some storage to meet demand. Meanwhile, nuclear can be used for carbon sequestration at geoengineering scales when it's not being used by the grid.

Could you explain a little more? I think you’re saying that if we have carbon sequestration machines but their constraint is that they take a lot of power to run, we can use nuclear to run those machine. Is that right? Or is there some other carbon sequestration potential of nuclear power that I’m missing?

Believe parent is comparing and contrasting the problems inherent in intermittent renewables vs nuclear.

Intermittent renewables (in scenarios shy of wanton overbuilding) result in deficits, which requires energy storage to address. Energy storage (aside from pumped hydro) is pretty carbon-messy.

Surplus, on the other hand, can be bled off into energy-negative carbon sequestration.

There's obviously lots of other points, but it's mostly fair under economically realistic scenarios.

Who is going to pay for the externalities of the fossil fuel industry? Maybe you will, maybe you won't. But if you have any kids, they certainly will.

Nuclear is not an option as the major energy consumption growth in the next 20-30 years will be in countries/regions where the current nuclear powers will not be willing to trust with nuclear power.

Nuclear power is the ONLY option, because no renewable energy source allows for all:

- easy storage

- constant availability

- cheap construction per MW/h

And we cannot afford to pollute our environment even more burning fossil fuels.

There are various studies on the topic. For Germany, the figures that stuck in my brain were these: We can go 60% renewable without much of a problem, 80% with strategic storage and significant grid improvements, 100% via off-shore windparks and power-to-gas (our natural gas infrastructure can store hundreds of TWh).

Energy storage cost is dropping rapidly and given enough storage, you have constant availability. Unlike what you claim, there's a lot of innovation on this front and solar/wind bids usually include it these days. These combined bids routinely underbid nuclear/coal/gas: it's already cheaper now; even when you don't consider subsidies.

So, you bring up an interesting point with cost per mwh. Nuclear is not nearly cheap enough to be competitive right now and would have to come down by magnitudes to out-compete solar/wind + storage in a few decades. I'd say a good price to shoot for with new nuclear designs that might still be too high would be around 0.1-0.5 cents per kwh in a few decades. That's only 10x less than current bids; you'd probably want to stay below that even. But anything over that would be dead on arrival in terms of profitability.

You dont take to account how much energy newer reactors produce. And to my knowledge its indeed "orders of magnitude" more than the old ones. This is simply because they burn whole fuel and not 1.64% of uranium old reactors do.

And I think we are way past the point where thinking about profitability should be our first concern.

ps. I find it hilarious when people talk about renewable energy sources but dont take into consideration energy storage. Batteries production may go down in price, but that doesnt change the fact how toxic that production is to environment and how big of a footprint it leaves for the future.

It remains the case that we should be thinking about how to maximize the CO2 reduction per $ spent.

Building new nuclear powerplants is not the way to do that.

It is in comparison to alternatives.

No, not at all. Many alternatives are much cheaper than building new nuclear reactors, per unit of CO2 avoided. New reactors are sadly very expensive.

And help us get rid of the waste old nuclear reactors created. Taking to account thwt we cannot store energy efficiently enough beside few edge cases, the ability to generate enough base power makes nuclear plants superiour to anything we have.

Solar panels production has very bad impact on the environment in different areas than CO2 and those panels are worthless after 10years. Smelting parts for windturbines has the same issue of huge amount of turbines which require maintenance and take alot of space to place them correctly.

All of those technologies have serious drawbacks. While nuclear powerplant using new reactors has only one - its expensive to build but will last a century or more.

New reactors are expensive because of current regulations. Tolerances in various areas can be reduced for reactor designs that can gracefully shut down with a loss of power.

If only the nuclear industry, or its remnant, were as good at making reactors as it is at making excuses.

What you wrote there would be true if the levelized cost of energy from nuclear weren't so high. As it stands, the dirt cheapness of renewables (and particularly of renewables as they will be a decade in the future as they continue down their aggressive experience curves) will make dealing with intermittency cheaper than going with nuclear.

It could make sense to continue to operate existing nuclear power plants while taxing carbon emission, but the CO2 tax needed to justify new nuclear plants would be outrageously high. Long before that level of tax was reached renewables would snipe the market.

And energy density is another major issue with renewables in the long run.

It's not. If we run out of land for solar, our energy demand would be so high that the direct thermal pollution from nuclear would be a showstopper.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact