The Next Nuclear Plants Will Be Smaller and Safer | Hacker News Reader

The Next Nuclear Plants Will Be Smaller and Safer

wired.com

No word here on how much they will cost to build and decommission or how much water they require, or what the plan for waste management is. I'd love to see some numbers here because without them it's easy to assume this is not cost competitive with solar+battery in +5 years given current trends.

I imagine you can find all sorts of numbers in their 12000 page report to the NRC, I assume located here

https://www.nrc.gov/reactors/new-reactors/design-cert/nuscal...

Yes, and this is the main document to read.[1]

There's some hand-waving on safety issues in Table 1.9-2. NuScale passes the buck on flooding issues to the plant owner. Also, there's some hand-waving on software safety issues: "The NuScale design applies RG 1.152, Revision 3 and IEEE Std. 7-4.3.2-2003 that it endorses. For RG 1.168, the requirements of IEEE 1012-2004 are tailored to the NuScale I&C development lifecycle, which is different from the conceptual waterfall lifecycle in IEEE 1012-2004. The applicable tasks from IEEE 1012-2004 to the I&C development are mapped. Some administrative mandatory requirements in the standard conflict with established Engineering or QA documentation requirements. The requirements of IEEE 1028-2008 are tailored to the NuScale I&C development lifecycle." This may mean "We use Agile and your outdated rules don't apply".

The key concept is that, since these plants are passively cooled and don't require pumps for cooling, many of the concerns about keeping cooling water flowing to prevent a meltdown don't apply. "For the NuScale design, the safety analysis shows that core damage does not occur during any design basis event.", says the application. What could possibly go wrong?

A big concern is that NuScale proposes to put up to 12 reactors in one connected pool. I haven't found the part yet where they discuss what happens if one leaks and contaminates the whole pool. Or the pool springs a leak and drains into the ground.

These are not small plants. A 12-unit plant is 720MW of electrical power, so it's getting close to a typical gigawatt sized plant. More small units, instead of one big one.

The history of power reactor meltdown incidents is roughly as follows:

- Three Mile Island - meltdown, big containment vessel, fully contained, expensive but not hazardous.

- Chernobyl - fire, meltdown, no containment vessel, radioactive material dispersed over large area.

- Fukishima - meltdowns, undersized containment vessels breached, radioactive material dispersed over moderate sized area.

A certain amount of skepticism about designs that "don't need" a big containment vessel is perhaps justified.

[1] https://www.nrc.gov/docs/ML1924/ML19241A398.pdf

There are designs that don't need a large containment vessel because they operate at normal pressure and there is no water that might expand by a factpr of 1000.

Look at the IMSR.

NuScale is a pressurized water reactor whose containment sits in a water-filled pit.

Isn't the pool secondary containment so leaking into the pool is bad but not really any different than if primary containment failed for any other plant.

You can find leaks in pools pretty easy by using a double lining and distributed sensors or in closed environments like this, by measuring net flows and looking out for any net change in volume.

The pool is for passive secondary cooling if the primary fails. It is outside the containment and is intended to boil off over 30 days if there is a complete blackout. 30 days is all you need for the decay heat because after that air cooling is sufficient.

Not 30 days. 72 hours. "Water inventory in the reactor pool is adequate to cool the NPMs for at least 72 hours without adding water." NRC filing [1], page 41, bottom of page.

A NuScale press release does say that. "The system is capable of providing 30 days of cooling without adding water to the pool."[2]

The web site hype goes even further: "Should it become necessary, NuScale’s SMR shuts itself down and self-cools for an indefinite period of time, with no operator action required, no additional water, and no AC or DC power needed."[3] But that's not what the NRC filing says.

Looks like they make bigger claims when they think they can get away with it.

[1] https://www.nrc.gov/docs/ML1924/ML19241A398.pdf [2] https://newsroom.nuscalepower.com/sites/nuscalepower.newshq.... [3] https://www.nuscalepower.com/

That accusation seems a little extreme.

The 30 day claim was published in January 2012 in response to the Fukushima accident: https://www.tandfonline.com/doi/abs/10.13182/NT12-A13556

Also, in "NuScale Technical Report Long-Term Cooling Methodology, dated January 2017, TR-0916-51299" (https://www.nrc.gov/docs/ML1835/ML18355A973.pdf)

"5.3.4 Long Term Cooling Evaluation Period LTC analysis is limited to three days. This timeframe is considered acceptable because: (1) the most severe conditions will have been captured within the 72 hour window analyzed, and any conditions that could reasonably be expected to occur beyond this time period are thus bounded by the 72 hour calculation, and (2) after 72 hours, operator actions can be credited. When realistic initial operating levels, temperatures, and decay heat are considered, the scope of the LTC analyses bound the expected level decrease in the reactor pool ultimate heat sink over 30 days, for up to twelve modules transferring decay and residual heat to the reactor pool."

I read this as that they ran a number of scenarios with extreme initial conditions and at the end of three days all operating characteristics were effectively the same as with typical starting conditions and therefore they expected the 30 day simulations would give the same result no matter what the initial conditions were. I don't think they are hiding anything here.

That's so heavily censored it's hard to tell anything from it.

> "For the NuScale design, the safety analysis shows that core damage does not occur during any design basis event.", says the application. What could possibly go wrong?

The thing with nuclear reactors is that this sentence was thought to be true for most designs, including those that failed to varying degrees (RBMK, GE BWR, B&W PWR).

You're going to have to show the reports that said such things ("core damage does not occur during any design basis event") for those old designs

It's more or less a tautology, because the most severe accident the reactor is thought to withstand is the design-basis event. AFAIK in the instances of Fukushima and Chernobyl/RBMK it was later thought that the design basis was simply incorrect.

Thanks for this link. I've only read a few sections, but I can't find any cost info at all. Also they're not really saying anything about waste management that's useful. Summary: "The SRWS processes solid waste by dewatering, decontaminating, surveying, sorting, and classifying solid waste for storage and eventual shipment to licensed offsite facilities." (basically the same process with the same issues I have with "regular" nuclear plants). They do answer my water concerns, though - looks like no external cooling water is needed in normal operation, but their design is food susceptible so it needs to be built in places that cannot flood.

The article includes an interesting note at the end:

> “I am skeptical of the ability to license advanced nuclear reactors and deploy them on a scale that would make a difference for climate change,” adds Fetter. “But I think it’s worth exploring because they’re a centralized form of carbon-free electricity and we don’t have a lot of those available.” At least in the US, it might be the only way nuclear power gets another chance.

I think that's a fair assessment. It's probably not going to make a lot of difference but it is still interesting to explore and invest in.

Regarding solar and battery, mass production capacity is basically the biggest hurdle here. Demand seems to be taking care of that (i.e. people are building so-called Giga factories to take care of this) but we're still an order of magnitude or two off to take care of most of our needs. Just the process of ramping up production is going to cut cost further. And of course at the current price levels, battery + solar is already highly competitive with just about everything else. Of course in the process of ramping up production, there are likely to also going to be massive technical improvements that will further drive down cost and performance.

And just to pre-empt the argument: darkness is temporary and local, which means it is much less of a problem than some nuclear proponents seem to claim. Basically, if your panels don't provide enough power when it is cloudy, install more. If your battery runs out in the middle of the night, buy a bigger battery. If the area you live in is susceptible to extended periods of darkness (aka. the polar night), import power using cables. On the other hand, if, like most of the population of planet Earth, you live closer to the equator this is not going to be an issue.

Nuclear is still going to be useful but just not as our primary source of electricity. The safety and securitt concerns alone would make this impractical. Even if we can deliver this technically and produce these things cost effectively, you'd still need a lot of security measures to prevent people from doing silly things like creating dirty bombs with the nasty stuff inside. Imagine a few tens of thousands of these things, it would be a nightmare from a security point of view.

You can do that but the capital effiency and overall system effiency will be even more atrocious.

I think we need a good mix of both.

Why do you think so? Solar + battery is already considered the cheapest option. How would spending more be a better form of capital efficiency?

Diversification.

Is it a lot more funding than space ? because spatial exploration, as cute as it can be, is somehow a lot less critical.

That's very easy to say, and I am definitely NOT saying you are wrong. But I'd be somewhat careful.

Space exploration has in the past provided us with lots of information that we can use to understand our own climate and planetary systems. Not only that, but the often mentioned advances in material sciences and other areas might end up helping us much more than the sunk cost at the beginning.

Darkness is temporary (in the sense of nights) only when close enough to equator. Here in Finland even as far south as you can go solar efficiency drops to almost nothing for a good 4 months a year. And in the north it goes to literally to nothing. And it isn’t very safe to rely on other counties for electricity over this period. Doing that basically hands the keys to freeze a sizable portion of our population to an external entity (government)

Though even now we aren’t independent when it comes to heating over the winters. We have to import oil, gas and coal. But with those one can have strategic stockpiles to last over the next/current winter at least if things go bad. Kind of similar for nuclear fuel. We have stockpiles for years but don’t mine it here (we could but economically much cheaper to buy from Sweden and Russia). Just much easier to stockpile that stuff.

But yeah for the vast majority of the whole planets population solar with batteries should work just fine.

I would be highly surprised if the habitable zone of our planet in 'sustainable' mode would be the exact same habitable zone in 'unsustainable' mode.

I wouldn't. We are roughly distributed by local food availability, and that correlates well with solar power availability.

The one large difference is that food is easier to import. But I am pretty sure we can solve the energy long distance trade problems.

Expensive nuclear is not going to save your energy-hungry industries when the cheap energy is available at low latitudes.

Boreal countries will be energy ghettos in a solar powered world.

Our energy hungry industries are building nuclear with their own money. And even with the delays of olkiluoto 3 they want to build more (but are having a hard time getting the permit).

TVO Teollisuuden voima (heavy industries power) is the company that built, operators and owns half of the nuclear plants in Finland (one of the owners of TVO owns the rest)

If they can get the financing from private markets to build more I say let them. None of the current/future plants were built with government money outside of them being the backer for the insurance.

You do not contradict what I wrote. Yes, your industries are going with nuclear. No, they will not be able to compete toe-to-toe with equatorial countries getting solar at $0.01/kWh, as they will likely be able to in a few years.

Will the equatorial countries have the skilled workers, raw resources, logistical infra (roads etc) required to run the plant? Energy is not the only thing you need to run a plant.

I doubt prices will never reach $0.01/kWh. At least here in Finland transmissions fees are a larger part of the bill then the energy itself already. So unless every plant builds an absolutely massive solar farm next to it (and never plans to sell its overproduction from the day) the network fees alone will be much more then that.

Why should they not? Is this something that dark skinned countries cannot do?

I think your position there is showing a thinly cloaked racism. I suspect much anti-solar talk has that as a motivation. The idea that white skinned boreal countries will become the future's "third world" may be intolerable.

The idea that white skinned boreal countries will become the future's "third world" is pure fiction.

The third world is characterized by not having, for example, a functioning transportation infrastructure. If Finland can't realistically charge their cars from solar and their choice is between paying somewhat more per kWh than Venezuela by using nuclear or some other non-photovoltaic power generation method vs. not continuing to have a transportation infrastructure, they're not going to stop having a transportation infrastructure.

And it's a damn stretch to frame this as a racial issue. You can expect places like India and Mexico to benefit from cheap solar, but only to about the same extent as "white people" places like the US and Australia. You would have to be an especially silly racist to hang your racial animus on solar power when you can reasonably expect more of the industry to set up shop in Arizona than Zimbabwe.

As cost of living rises, more people will migrate to cheaper countries, including the skilled labour that moves with their spouses to a country more favourable to raising a family.

The people left behind will be the poor who can’t afford to relocate and the excessively wealthy who don’t care about living expenses.

A map that shows population by latitude and longitude:

https://www.datagraver.com/thumbs/1300x1300r/2016-09/density...

This is rather beside the point, but this is the population divided by the land area, which accounts for things like the large spike at about 22 degrees East (Reykjavik, and not much else.)

>Darkness is temporary (in the sense of nights) only when close enough to equator.

But cloudy weather isn't. Ultimately that's the problem with doing a straight cost comparison between solar and wind. You have to build much more capacity to account for times when they aren't producing at 100%.

With a lot of energy efficiency, heat/cold storage, electricity storage and demand-response you can go a long way while limiting the extra "capacity to account for times when they aren't producing at 100%"... . But of course, having different (renewable) source of energy on the grid always make sense and often make it easier

Sure, but you still have to account for the cost of that storage and demand response. And when you're talking about days worth of energy storage things get very expensive.

Nuclear power plants vs. solar+battery comparisons require one more dimension when compared: energy density. This will tell you how much weight and area is going to be allocated to cover the energy need of the customers you would like to cover (eg. for example a country).

Energy density is largely irrelevant. What matters is cost, and in most of the world the energy density of solar does not cause a large increment to the cost. Land is mostly cheap.

I often watch videos of Jean Marc Jancovici, a French consultant on energy.

Cost is not really relevant to energy because the entire human civilization requires energy to function.

Also, renewables can barely compete with nuclear, because they cannot deliver enough energy when you need it. Renewables also require more metals and mining, so they emit more.

The coal and natural gas industry likes renewables because coal is on-demand energy.

Nonsense. Cost is always relevant, since there is always a variety of ways to solve a problem, and cost is used to choose between them. This is true even of things that are vital, like energy.

Cost must be properly accounted for, of course, including externalities.

If you can accurately calculate the vast implications of the price of energy, I might listen to you. There are things where the price doesn't say a lot of things. It's true for energy since it's a very long term investment, which also has implications on infrastructure.

Generally it's pretty complicated to evaluate the public interest, and I don't think you can put a price tag on public interest.

It doesn't change the fact that nuclear is always better. It's just that private funding doesn't like it because it's a very long term investment.

If we can't determine the implications, then what do you suggest we do? Make decisions by examining goat entrails?

I understand why nuclear fans want to say cost doesn't matter. If cost matters, nuclear sucks. I understand how jarring this new reality (that nuclear has been priced out of the market vs. other CO2-free alternatives) is. Nuclear fans are still in denial about it, but declaring the falsehood "nuclear is always better" doesn't change that reality.

Again, renewables are not baseload, meaning it's not on-demand energy, meaning renewables will emit co2 because their require coal or gaz to supplement them. Storing electricity is also pretty damn difficult, and it adds more costs.

I had this argument several times.

Can you power electrical trains with renewables? No, because you can't decide when to have wind or sun.

Concerning costs, this consultants made difference estimation and even when he favors renewables, they are still 2 times more expensive that nuclear.

Even someone who worked with the Obama administration for renewables realized nuclear was better.

Baseload isn't on demand energy either. It's "take it or leave it" energy. Baseload USED TO BE the cheaper per kWh, so grids were designed to have baseload + dispatchable sources to fill in the rest.

But renewables have rendered this design obsolete.

Now, the cheaper sources are not baseload, but intermittent. The optimal grid design is become one of using intermittent sources, then filling in around those with some combination of storage and dispatchable supplies. Expensive baseload has no place anymore in this situation.

Your claim that renewables are 2x the cost of nuclear is an easily checked falsehood. The levelized cost of energy from renewables is 3-4x less than new nuclear plants.

Again, intermittent power source are not really useful because there are times when you need power and times when you don't, and nobody decides when there's sun or wind, not to mention seasons.

Essentially, it means renewables = coal+gas. Not so good for low emissions.

Jean Marc Jancovici say that cost "should" not be relevant ; however currently this an important criterion of choice (if you double the price of energy tomorrow, you get riots)

Renewable + heat/cold storage + electricity storage + demand-response + energy efficiency = that can deliver enough energy when you need it (and probably much cheaper than with nuclear)

"probably"

Energy density is only important in a few use cases since electric transmission is largely a solved problem and even in urban areas we currently have a lot of easily usable sun-facing surface area where panels can be installed.

>> since electric transmission is largely a solved problem

Really? I thought it requires a large investment that has a big impact on the environment which is an external cost to energy production and usually people do not care about it. Unless we are able to produce mass amounts of superconductive materials and deploy this solution to replace traditional infrastructure we have a wasteful way of transporting energy.

http://insideenergy.org/2015/11/06/lost-in-transmission-how-...

> solar+battery in +5 years given current trends.

Current trend is that solar+battery won’t be useful for a long time. Solar with current trends currently has no hope of replacing base-load because the storage options are terrible.

Current trend is that solar + battery is already becoming standard at utility scale. Bids in the US west for solar are coming in with integrated battery storage at prices that new gas capacity cannot match.

No, there are no solar+battery projects in the west (at least in the US), that are cost competitive with natural gas. If that were true it would be major news.

Arguing about what is best for baseload makes no sense.

It's like comparing ICE vs battery electric vehicles on the basis of what's best for the non engine/motor parts, or "base-car".

People need a whole car and a whole energy system. Coal and nuclear, which are suited to this artifical contstruct of baseload, are not good for providing 100% of energy requirements on their own or in partnership with others and that's why no one is building them anymore.

Arguing for base-load is arguing for the whole energy system. The only way solar looks favorable is by ignoring base-load requirements, which is why it needs to be explicitly called out.

> I'd love to see some numbers here because without them it's easy to assume this is not cost competitive with solar+battery in +5 years given current trends.

[On nuclear fusion] “It's kind of as instructive to ask what's not the problem as it is to ask what is the problem. There is a problem. The problem is not cost. It's not that energy generation technologies are expensive. The cost is lower than it has ever been to generate electricity.

It's also not intermittency, and there are a lot of studies out there looking at getting to very high penetration of renewables, and how you manage that grid with those intermittent sources, and the answers sort of range between, let's say, 60% penetration of renewables to 100% penetration. I can't argue about that, but fundamentally I think it is possible to manage that grid and, even more so, the cost of doing so is not prohibitive.

[A consultancy called Systemic] added on the cost of intermittency, basically paid for with lithium ion batteries and gas peakers to deal with the hardest intermittencies to deal with—which is not when the sun goes in front of a cloud, but when it's summer or winter, that difference. So this isn't a carbon-neutral grid, it still has gas in it, but the total cost of intermittency adds about $15/MWh to the levelized cost.

So you take solar, for example, from 35 to 50. Well, gas costs 80, so this doesn't change the picture. Solar and wind are still the cheapest sources of electricity.

The problem, and this is where fusion fits, and this is where any new energy technology fits; the problem is scale. This is looking at the growth in deployment of solar and wind in a global sense. [...] This is the total sum of wind and solar based on current policies. We wanted the most aggressive scenario for the deployment of solar and wind, because we wanted to know the answer to the question: do we actually need fusion? So we took these curves, this is continued exponential growth. We did this last year; reality is already behind this model, because last year, 2018, growth in renewables flatlined for the first time. We assumed continual exponential growth. You add all of that up and you compare it to the total demand for electricity.

[...] Renewables can get us to half the required electricity generation. A lot of the stories you see in news take that number and compare it to how much electricity we need now, but you know electric cars are coming, right?, electricity demand is going to increase. If we're going to get to net zero, whilst overall energy consumption might be falling, the demand for electricity is substantially rising because actually only about 20% of energy is electricity, so, you know, the energy in my car I drove here this morning was not electricity.

That is what creates this clean power gap and this is why ultimately we need new technologies. We cannot get to the scale required to meet net zero by 2050 with the technologies that we currently have.”

https://youtu.be/DtvcEkIb4D4?t=653

So, he doesn't disagree with claims solar can get to 100%, but somehow thinks it's not enough? This is not making any sense.

Plugging in the numbers and running a linear programming model is not the same as building factories and installing generating capacity and transmission lines.

And the idea that we cannot build the factories is justified by... what? It seems he has pulled his negative conclusion out of his butt.

No one is building new capacity (with current tech) because existing factories are operating at a loss.

As for new tech, 1366 Technologies has built a factory in Malaysia and was expected to ramp up their kerf-less wafer production in Q3 2019 for sale to Hanwha at their neighboring plant.

https://1366tech.com/2019/02/26/1366-technologies-and-hanwha...

Meanwhile, another of my favorite companies, AltaDevices has recently shut down and is looking for new investors.

https://pv-magazine-usa.com/2019/12/09/alta-devices-hopes-ou...

I am certainly hopeful that eventually new capacity will come online that can compete with existing factories, but the fact remains that numbers from a linear programming model do not mean that the factories exist to build all that solar.

That doesn't mean the factories can't be built, it means it doesn't make economic sense to build them right now, in the current global environment that still lacks carbon taxes or the equivalent. It also means it does not yet make sense to rip out much of the installed capacity and replace it with renewables (a point that requires a lower price than just dominating replacement of end-of-life plants and building for growth in demand.)

Agreed. I think one way of looking at it is that building factories does not scale in the same way as building plants. You can build a plant that produces 1GW base and it can start generating when you turn it on. An equivalent factory making 250MWp of solar PV cells will take 20 years of production to build up to an equivalent installed base (when it can start producing cells to replace retired 20 year-old cells.)

If you try to scale up factories for faster growth you will have to start shutting them down when you hit an oversupply after 5-10 years and then where will your replacement cells come from?

I think it's just a speed bump due to running into limits on new capacity. In the US, for example, demand for electrical energy is nearly flat. Once the price of renewables falls enough the existing plant (much of which is only there because the capital cost is sunk) will start being replaced before its EoL.

BTW, the argument being made here against renewables would apply equally well against nuclear. Hail Mary Reactors will also require scaling up of factories to make them.

True, but maybe with slightly better margins. ;)

Companies are building a lot of new solar factories in China.

"Solar PV capex trending at US$9 billion annually as new GW fabs in China slash investments required"

https://www.pv-tech.org/editors-blog/solar-pv-capex-trending...

China is where the ecosystem of experienced manufacturers, material suppliers, and manufacturing equipment suppliers all comes together now. The rest of the world's solar manufacturers are struggling because the Chinese ones have such economies of scale that it's difficult to compete head-on. (Barring perhaps First Solar. First Solar is still doing ok because it has achieved multi-gigawatt manufacturing scale too, and because its product has advantages when operating in high temperature conditions. Also there are a few other solar manufacturers that can weather the storm because they're part of large conglomerates, like LG.)

Non-Chinese solar manufacturers like to cry "unfair competition" at low Chinese solar prices, but after reading industry trade publications for several years I am skeptical of that argument. To me it looks like Chinese PV companies did get government protection and incentives to establish themselves, but no worse than Western countries give to their own favored industries. And now they can produce good products at unbeatable prices. Not a whole lot different from Japan overtaking American radio and TV manufacturers in decades past, or (more recently) China rapidly overtaking incumbents to become the world's largest lithium ion battery manufacturer.

The claim is that a renewable grid would be manageable and affordable IF we could produce enough solar and wind installations, but that even optimistic projections don't have enough supply (of solar/wind/etc. installations) to get there in a timely manner.

But this logic makes little sense. It's not like there's some fundamental limit to the supply of wind or solar equipment. If we want more, we build more factories. Nuclear advocates are implicitly admitting this when they propose building new reactors at large scale for which there are no existing factories.

It's an economic issue. Solar reaches a price advantage in Phoenix before it does in Toronto because there's more sun, so people in Arizona are willing to pay a higher price for panels. Or there is more demand during the day so it's profitable much sooner to buy solar to satisfy the daytime/nighttime load differential than if you need to combine it with batteries.

So you build a bunch of panel factories, sell panels to Arizona and pay off most of the fixed costs of building those factories. But then the markets willing to pay higher prices get saturated. Once you've sold them as many panels as they need, they already have them and stop buying as many. Lower demand. So by supply and demand, the price comes down.

That's good -- now you're competitive in Northern California and people start buying panels there. But it's also bad -- it's profitable to keep operating your existing factories which are already built, but at the lower price it's not as profitable to build new ones. Eventually the price gets low enough that production capacity stops growing.

You can use the existing production capacity to get to 100% eventually, but if you wanted to do it faster you would need higher prices to justify building more factories. Only then there would be less demand, so you still can't increase the growth rate.

Nuclear comes at it from the other end. Can't compete with solar in Phoenix for the daytime peak but it can in Toronto for baseload. Which means there is greater demand for solar for some uses and greater demand for nuclear for other uses, and you replace carbon faster when you build both at once.

New nuclear is not competitive in Toronto. Ontario gave up on it ten years ago, when the only bid they got came in a factor of 3 too high.

https://www.thestar.com/business/2009/07/14/26b_cost_killed_...

Nuclear is the second largest generation source in Canada after hydro. One bidder was not competitive ten years ago.

And it's a bit silly to argue against doing things that make it more cost effective to build something (improving regulatory efficiency, increasing production scale) by arguing that it costs too much to build. The whole idea is that if we did the things then it wouldn't cost as much.

These NuScale reactors cost less (even per MW) than that bid in Ontario, do they not?

There were no other compliant bidders ten years ago.

What was notable about that process was the province required bidders to taking on risks that the province would not back. The only bidder willing to do that (Areva bid but did not do so, so their bid was not compliant) priced the cost of the risk into the bid.

This demonstrated that, properly priced, nuclear is far out of the running economically. It only gets built when the risks are forced on others (taxpayers, ratepayers) outside a fair competitive process.

In retrospect, this should have been a serious warning that other new builds in the "nuclear renaissance" were extremely risky, as they turned out to be.

Given this history, I would believe NuScale only after they've built their Nth-of-a-kind system on budget and aren't bankrupt.

> What was notable about that process was the province required bidders to taking on risks that the province would not back. The only bidder willing to do that (Areva bid but did not do so, so their bid was not compliant) priced the cost of the risk into the bid.

The problem with these risk calculations is that you're asking a private insurance company to issue a very large policy with a small probability of payout. The major cost of those policies isn't actually in the risk itself, it's the cost of holding enough capital in reserve to be able to satisfy the policy size independent of the risk probability. They're not allowed to just invest that money in the stock market, so you're essentially paying them to forego the market rate of return on a huge pile of money for the entire term of the policy, even if no claim is ever filed.

That's why it's typically a government providing the insurance in these cases -- they're not required to hold the money in reserve so they don't have to effectively pay interest to hold money that might never actually have to be paid out.

Also notice that the competition there still wasn't solar, it was fossil fuels. And if you want to talk about pricing in the that risk then nuclear looks very attractive.

> The problem with these risk calculations is that you're asking a private insurance company to issue a very large policy with a small probability of payout.

And the problem with the opposite is that risk is foisted off on unwilling consumers. The bidding process is subverted.

If risk is placed on the groups selling the technology, they have an incentive to work on technologies that are inherently less risky. Renewables, for example, typically come in within 10% of the bid price. Yet you would not allow this risk advantage to have any place in the decision process by subsidizing nuclear's risk.

> And the problem with the opposite is that risk is foisted off on unwilling consumers. The bidding process is subverted.

It isn't the consumers who take on the risk, it's the government. But nobody's asking them to do it for free, just charge an actuarially honest insurance premium that doesn't include having to effectively pay interest on a giant reserve fund even if it's never used.

> If risk is placed on the groups selling the technology, they have an incentive to work on technologies that are inherently less risky.

And yet they would still be stymied by a similar requirement.

Consider that solar panels have some nasty stuff in them. Heavy metals. That's well and good so long as they stay inside like they're supposed to and then get properly recycled, but what's the worst case scenario? Maybe something like a major hail storm that cracks open the panels, followed by severe acid rain that leeches the metal into the soil and the groundwater, or maybe a big forest fire that burns them and releases the toxins into the air.

A 1GW solar farm would have something like a million panels, so tens of millions of pounds of material, maybe a hundred million. If they all burned, the cloud could spread over a huge area, or pollute the soil and groundwater for millions of people. So all I ask is for you to have to carry $200,000,000,000 worth of insurance just in case that happens. The worst case is really bad but the probability of that happening is pretty low, so you won't have any trouble finding someone to write a policy that size and whoever you do find will give you a good rate, right?

Assuming risks like that is what governments do. If your giant solar farm burns to a crisp and you go bankrupt, they're the ones who will have to make it a superfund site, clean it up and bail everyone out.

Doing the same thing with nuclear isn't a special subsidy, it's standard operating procedure across all industries. Requiring nuclear plants to account for every last penny of risk or externality is fine if they're going to do the same thing for everybody else, but they don't. So are we going to require everybody to insure against the worst case scenario, or not?

Solar risks are often dismissed, more probable, but still much less nasty.

Typical solar cells are made of glass/ceramics so they don't actually burn and the cleanup should actually be manageable.

Ah, so you're telling me that your proposed new power plants can't meltdown. Well that's great to hear, but you know it hasn't been deployed at large scale for very long, so we don't actually have a good actuarial model of the true risk it poses.

Doesn't that mean we should prohibit operating it at scale until we have some better data on the risks of operating it at scale? Or at least require you to carry the insurance in the meantime, say for six to twelve decades?

Isolated demands for rigor can make anything too expensive to be competitive.

The risk that was being discussed in reference to Ontario was not the risk of meltdown, it was the risk the plant would blow way past the promised cost.

On that metric, we know renewables are far less risky. They typically come in within 10% of the bid.

I think what he's saying is "At the current construction rates for solar and wind, or even with a quite aggressive increase in construction, the UK still won't meet its net zero carbon by 2050 emissions target, so we're on course to keep gas power stations operating because it'll be easy"

That's 30 years away. Given the rate of change in the rate of construction of solar and wind in the past 30 years, that extrapolation is very silly. To give you some idea: the global cumulative installed PV capacity has increased by about four orders of magnitude since 1990.

Global Solar PV installations are forecast to flatten out at 125GW (peak) annually throughout the early 2020's.

https://www.greentechmedia.com/articles/read/global-solar-pv...

Figure 20% of peak for 24/7 power production (using nonexistent cheap storage) and you get 25GW capacity installation per year for solar.

Meanwhile: "Over 100 power reactors with a total gross capacity of about 120,000 MWe are on order or planned, and over 300 more are proposed."

https://www.world-nuclear.org/information-library/current-an...

So, globally I think nuclear can give solar a run for its money, although in some countries nuclear may not be an option due to public opposition or access to the technology.

I would be nice if you didn't switch units between 25GW and 120 000 MW.

We have 25GW/year vs. 120GW/? years. If you scroll to the bottom table, and sum a few numbers you get:

  2020: 15MWe
  2021:  7MWe
  2022:  8MWe
  2023:  8MWe

Wait, what?

"The growth flatlined" is a pretty confusing phrasing. What does it mean, that the trajectory is only parabolic? (Their graphic does certainly not look linear.) Things can not stay exponential forever, besides, let's ignore that this is a single data point on the crazy noisy area that is economics.

But anyway, is that really a talk saying we should invest in fusion because solar won't scale fast enough?

His graph assumed continuous exponential growth in deployment. In reality, deployment of solar in 2018 (97.4 GWdc) was slightly less than in 2017 (97.8 GWdc).

> But anyway, is that really a talk saying we should invest in fusion because solar won't scale fast enough?

Yes.

Which is hilarious and all the reason one needs to dismiss him. Fusion has basically zero chance of being competitive anytime soon, and possibly ever.

First Light Fusion, Commonwealth Fusion Systems, and Tokamak Energy are all aiming at net energy by 2025 and grid-connected power by 2030. Lockheed Martin wants power plants at scale in the 2020s, with designs small enough to power aircraft (though their approach is more novel than CFS/TE physically). All four of companies have cost-effective designs radically more economically feasible than the JET/ITER/DEMO pathway of old.

There's no magic to fusion, it's just a matter of finding a way to do it economically.

Company goals, and $5, will get you a mocha grande at Starbucks.

None of those have any real chance of being commercial viable. The tokamak approaches, in particular, are both much larger than, and much more complex than, a fission reactor of equal power output. Yes, they are more cost effective than ITER. Only 40x lower power density vs. 400x lower. Yay?

NuScale is about 3x3x20m for 60 MWe. SPARC is about 4x4x4m (?) for about 50-100 MWe; that only includes the reactor proper, but the rest should be no less compact than any other plant.

I'm talking about the power density of the primary reactor vessel (the part in a PWR that has things too radioactive for hands-on maintenance). In current PWRs, that's about 20 MW/m^3, vs. about 0.5 MW/m^3 for ARC.

OK... so? This seems like a pretty meaningless statistic. The reactor core for a magnetic confinement fusion reactor is pretty much the only meaningful radioactive waste from the process, and within 50 years it turns itself into low-level waste. This isn't a zero quantity of waste, but it's comparatively trivial.

Even if you have to replace a piece, you just unfold, crane the old one out, and crane the new one in.

It's meaningful because cost is related to size and complexity.

The core of a fission reactor of a given power output should be smaller and simpler than that of a fusion reactor. As a result, it should be much cheaper, and also more reliable.

The parts outside will be very similar (even fusion reactors will require containment buildings, due to the very large amounts of tritium involved).

Fusion designs go even further and imagine operating at high temperature than LWRs. But this also drives up cost; materials problems rapidly become worse as temperatures increase. High temperature fission reactors have never caught on, for this reason.

It follows that fusion power plants will not be cheaper than fission power plants.

People have priced these already, it's competitive.

Fusion requires fewer safeguards, less insurance, and is more repairable than fission. Reliability isn't an issue just because it's 4m³.

Why would fusion reactors need ‘very large’ tritium supplies? SPARC would use, what, <100g/day? And it would generate excess, so they wouldn't need a stockpile. Tritium isn't even particularly dangerous; it goes away on its own, and doesn't stick around in biological systems.

> People have priced these already, it's competitive.

I don't believe these estimates, either in the input data or the methodology. They are basically an exercise in "how optimistic can I be before no one believes me". It's not as if any shenanigans in them will be checked against reality anytime soon. They aren't a good counter to the simple argument of "larger, more complex, and made of more exotic materials implies more expensive."

But in any case, let's look at ARC, shall we? The cost comes to $29/W(e), very much higher than fission reactors. They have to resort to "and the Nth of a kind plant will be a factor of K cheaper". Never mind that the closest analogy, nuclear fission plants, has not shown good experience effects.

About tritium: I don't think you grasp how problematic this material is. The amount of tritium consumed in a 1 GW(e) fusion plant in a year would be enough to contaminate 2 months worth of the flow of the Mississippi River, at New Orleans, above the legal limit for drinking water. Confinement of tritium is going to have to be damned near perfect for a DT reactor to be acceptable.

I'll agree that if future designs look like ARC, and cost $5-6B, fusion won't be economical.

That is a space reactor. Send it to Mars or the 500AU solar gravitational lens area in the direction opposite Sagittarius A. Let it rot in place and don't worry that civilization falls, then 4000 years later the Mormons and the Scientologists are fighting for control of Yucca mountain from which they drill holes in search of Plutonium.

> “I am skeptical of the ability to license advanced nuclear reactors and deploy them on a scale that would make a difference for climate change”

I know of at least one design that is likely to be commercialiced in 5-10 years.

The 195 MWe IMSR is much smaller than the nuScale reactor and is already in the middle of the second pre licicing review of cnsc.

Main advantage of the imsr is that it operates at normal pressure and it has a much better fuel economy. It produces six times more with the same amount of fuel as a LWR.

I had to look this up. The CNSC is the Canadian Nuclear Safety Commission. Their Pre-Licensing Review is an optional process intended to streamline the eventual license application. (https://nuclearsafety.gc.ca/eng/reactors/power-plants/pre-li...)

The NRC and the CNSC have also agreed to a joint review process that might perhaps allow the same design to be used in both Canada and the US. (https://www.terrestrialenergy.com/2019/12/terrestrial-energy...)

However, the ISMR is at least three years behind NuScale who started their NRC application in December 2016 and are well along in the process.

If you look at the progress at the CNSC, then NuScale appears to be one year ahead. The IMSR should finish the second phase in October 2020.

Terrestrial Energy plans to have the first commercial plant on the grid in the next decade.

I don't know enough about the process to make comparisons, but NuScale currently expects to be producing grid power in 2026. Nothing against Terrestrial Energy or molten salt reactors which is certainly an interesting tech. NuScale is about as boring as all get-out and might face fewer regulatory hurdles, but it might also have a harder time competing against better tech.

> It produces six times more with the same amount of fuel as a LWR.

Really? From what I've seen (https://www.terrestrialenergy.com/wp-content/uploads/2018/09... ) it's roughly equivalent to LWR's.

You appear to be right, I misinterpreted something from a talk of David LeBlanc.

From the article:

>> NuScale’s reactor is 65 feet tall and 9 feet in diameter, and is housed in a containment vessel only slightly larger. About the size of two school buses stacked end to end, you could fit around 100 of them in the containment chamber of a large conventional reactor. Yet this small reactor can crank out 60 megawatts of energy.

>> The review process is brutal—NuScale submitted a 12,000 page technical application—and will likely stretch on for at least another year. But the company has already secured permission to build its first 12-reactor plant at the Idaho National Laboratory, which may start supplying power to communities in Western states as soon as 2026.

A couple extra ideas for these beyond land-based power generation:

1) Put a couple of these on trans-Atlantic cruise ships, designed for speed, to make the journey in 3 days (at 50 MPH) carrying 2,000+ people.

2) Cargo ships that operate on the backbone long haul routes. If there are concerns about these getting too close to shoreline or population, just have them only operate 10 miles from land. Other cargo ships can then load and unload them in open water. (This would require some faster loading/unloading mechanism, maybe something where the front would open up and slide out the entire deck into the other ship.)

Thoughts?

The damage from an emergency at sea could be much greater than one on land.

The thing you get in the sea is unlimited free cooling and radiation shielding. You could dump the core onto the seafloor and not really have to worry about anything except the fuel elements eventually corroding and polluting a small area.

There are 11 known reactors dumped into various oceans and nothing terrible has come about from them.

Correct

The major concerns seem to be hijacking/piracy, clearance to dock at ports, and the general umbrella of proliferation concerns.

They don't want people taking these and using the material for bad things.

If there was a way around that, then maybe they would be economical. The cheap fuel costs in the past made the NS Savannah non-competitive, but I doubt that's true now: https://en.wikipedia.org/wiki/NS_Savannah

That makes a lot of sense; probably why we only see nuclear reactors on military vessels.

I've thought about this somewhat. We only trust the military to run nuclear reactors; ok, can we work with that? The US military is already a grift and jobs program; maybe we can turn the Navy into a grift and jobs program that is also an electricity utility.

Make them power all the shipping, oceanic towboats.

Not true. The fleet of Russian icebreakers relies mostly on nuclear propulsion. Wikipedia lists four different cargo ships equipped with a nuclear reactor at some point of time. The regulations and infrastructure are lacking but the interest is there.

Burning oil to move goods around the world is not a sustainable long term solution. Nuclear propulsion might be.

I wonder if we're over-reacting with anti proliferation.

It takes 3 very difficult achievements to build a nuclear bomb. Access to reactor grade uranium is only one of them.

I'm not sure the dangers of potential proliferation outweigh the tangible deaths per year that result from large ship pollution.

Building a dirty bomb isn't difficult, if raw materials is readily available.

Dirty bombs are cold war FUD. You could build a dirty bomb out of some smoke detectors. You could build a dirty bomb from the countless orphan sources scattered around the world with far less fuss than attacking a ship and causing an international incident. You could also build much more potent terror weapons without using any nuclear materials.

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

The biggest threat a dirty bomb poses is fear. Meanwhile shipping pollution is estimated to be responsible for hundreds of thousands of deaths every year which we just take as a fact of life.

Reactor-grade uranium isn't sufficient either. It's enriched to a maximum of 20% U235. A bomb requires over 90%, and getting to that requires the same kind of enrichment facilities you'd need if you started from uranium ore.

But fission reactors also produce plutonium. Using that is another possibility, but you need very pure Pu239. Once the reactor has been running for over three months you start getting a lot of Pu240, which is a serious contaminant for bomb fuel. Separating those is not currently feasible.

So one expedient for nuclear ships would be to run the reactors a few months in secure conditions before putting them to sea. Reactor-grade plutonium is still rigorously controlled, because it might be possible to make it explode, but nobody has ever done it.

https://www.world-nuclear.org/information-library/nuclear-fu...

> Reactor-grade plutonium is still rigorously controlled, because it might be possible to make it explode, but nobody has ever done it.

The US tested a bomb made from reactor grade Pu in 1962.

From my source above:

> a 1962 US test using UK plutonium from its Magnox reactors had a relatively a high level of Pu-240 but evidently less than ‘reactor grade’ as subsequently defined

Fair enough. Though to be pedantic, at the time of the test, it was considered reactor grade. The subsequent split of the definition of reactor grade into fuel grade (8-20% Pu240) and reactor grade (>20% Pu-240) occurred in the 1970'ies.

That being said, there seems to be "evidence" (maybe more like conclusions that can be drawn from published articles by people with weapons experience etc.) that Pu with almost any isotopic composition can be used to make a usable (as in, very low probability of pre-detonation, low enough radioactivity to not pose a threat to personnel handling it) weapon.

Now, I don't think that terrorist capturing a nuclear powered cargo ship and then making a Pu bomb is a particularly big worry. Making a Pu bomb from spent fuel (whether with weapons grade Pu or reactor grade) requires reprocessing technology (e.g. PUREX) as well as the engineering to create an implosion device, and is probably out of reach for non-state actors.

The worry AFAICS with reactor grade Pu is that an advanced non-weapon state sitting on a big pile of separated reactor grade Pu (cough Japan cough) could relatively quickly (e.g. weeks/months) create a bomb if they so wanted, compared with building weapons grade Pu producing reactors and running them, which would be a several years long project.

Godzilla?

(It’s a joke of course. HN can be sometimes too serious)

Seems like coastal real estate is fucked either way.

And there are already active civilian nuclear propulsion vessels, mostly russian: half a dozen icebreakers and the icebreaker cargo ship Sevmorput.

A variant of the concept is the floating power plant Akademik Lomonosov, a barge housing 2x35MWe reactors. Though somewhat oddly it's not intended as a mobile power plant, it replaces a "normal" power plant being shut down in a far eastern autonomous district.

> You could dump the core onto the seafloor and not really have to worry about anything except the fuel elements eventually corroding and polluting a small area.

Absolutely not. What you're saying is true for nuclear disposal- if you bury nuclear waste under the ocean floor there are no currents and no water table to disturb it, unlike on land where coolant water will rush towards drinking water, smoke does not diffuse evenly, and sediment does not naturally bury heavy isotopes.

It is absolutely not true for an accident. Radionuclides from Fukushima are measurable anywhere in the Pacific ocean. They're all over the planet. That's key though, because such even distribution means that even very dangerous isotopes are very quickly reduced to safe concentrations, or at least lower than background radiation.

On the other hand it is extremely difficult or impossible to save a priority environment if there is a real disaster. Convection will be driving far more radioactive material into the area than a land accident. You're not gonna ever have a meltdown (they already basically don't happen on land), but even a relatively small breach would have the potential to kill an entire area. Over most of the ocean that might be fine, but spawning areas or corals would be huge losses.

It doesn't matter. Because water is one of the most effective shields against radiation that you can possibly have. The effects are kept localised. Alpha to mm, Beta to cm, Gamma to 10s of m. To put things in perspective, you can take a swim in a spent fuel storage pond and be exposed to less radiation than outside it.

The contamination from fukushima is detectable all over the planet just like all modern steel is detectably contaminated from 1960s nuclear testing[1]. It doesn't make it any kind of threat to the environment. We're talking about the same order of magnitude concentrations that are used in radiocarbon dating.

And the very dangerous isotopes you speak of, they have a very short half-life.

See also, the Oklo natural nuclear reactor complete with all the associated waste/contamination and the fact that it had little to no impact on the surrounding environment[2].

At the end of the day, there are 11 known and god knows how many unknown nuclear reactors dumped into the sea, and things have turned out pretty okay. One of them is even a popular dive site.

[1]: https://en.wikipedia.org/wiki/Low-background_steel

[2]: https://en.wikipedia.org/wiki/Oklo

Shielding is totally irrelevant. Even on land it's insignificant compared to the inverse cube law- spreading the dose reduces it much faster than the shielding, once you aren't right next to the reactor. Radiation exposure is not caused by proximity, it's caused by breathing and eating nuclear material. Water makes that FAR faster.

Again you're describing a sealed or mostly sealed, cold reactor, which is what most spills have been like. That is not what an accident would be like. It's a totally different scenario.

> And the very dangerous isotopes you speak of, they have a very short half-life.

Minutes, hours and days- easily long enough to kill local life outright. My point was that the local effects underwater would be far more disastrous than a similar accident on land, if there is life where the accident happens.

> See also, the Oklo natural nuclear reactor complete with all the associated waste/contamination and the fact that it had little to no impact on the surrounding environment[2].

It was active during the precambrian, and buried underground, which was again the exact assumption of yours that I had an issue with. You are really, fundamentally not understanding what I am saying- a nuclear accident is extremely different from disposal.

In a worst case where all the fuel simultaneously becomes a suspended powder, would kill a bunch of sealife in an area smaller than 100m radius. We do far worse on a regular basis with commercial fishing.

You make a sea reactor dump sound like China Syndrome. The fact that 11+ of them happened with no significant problems makes it pretty clear that you're exaggerating.

Microplastics and plastics in the ocean are a far more serious and far more tangible concern than a hypothetically hijacked ship hypothetically dumping the core which hypothetically turns into powder form.

I'd be more worried about people stealing the reactor. How many armed guards do you want to have on board?

I imagine disconnecting a reactor would trigger an alarm. Not particulary easy to steal a hot two bus sized item with a structure built around it. You'd probably need several big cranes and other logistics involved.

I'm thinking they're getting close to the scale where you could put wings and electric motors on them.

Except crashes~~

The New Zealand Nuclear Free Zone, Disarmament and Arms Control Act 1987 is arguably the strongest anti-nuclear weapon domestic legislation in the world. It bans nuclear weapons and propulsion from New Zealand's land, sea and airspace out to the country's 12-mile territorial limits.

Perhaps they might begin to care about the environment more than their fear of nuclear science and make exceptions for propulsion.

How is this related? Are you quibbling with the 10 mile figure in GP's comment? Or suggesting that NZ is some substantial portion of the hypothetical target market for GP's hypothetical nuclear cruise ship? Something else?

Nuclear-powered US military vessels (subs and aircraft carriers, at least) already sail all around the world. I guess they don't enter NZ's 12 mile zone, or get some exemption when they do.

A ship can not go faster because it has a powerful engine or a near limitless energy source. A ship's speed is limited by design, especially with hull length. You cannot make a cruise ship go with 50kts.

50mph not 50 knots. I took one of these on a 75 minute trip last weekend. They cruise at 47mph and top speed is 55mph. https://en.wikipedia.org/wiki/HSC_Fjord_Cat They use huge amounts of diesel fuel, but that would not be the case for a nuclear version.

Edit: This version does 67mph and is powered by two 25 megawatt engines. https://en.wikipedia.org/wiki/HSC_Francisco

Sorry, when you said cruise ship, I was thinking "royal carribean" type ships. Cats can go much faster obviously.

My point is that the power alone can not make a ship faster. Hull length and shape determines max speed.

Still not quite understanding the point.

You mentioned even with unlimited amount of energy and power the speed is still capped and limited by Hull Length and Shape.

This reads to me if I could get a Nuclear Fusion reactor in my ship that has 10 times the power my Max Speed would still be the same. This doesn't sound right to me.

Drag increases dramatically above the hull speed. Obviously more power means more speed, but if you want more speed for a fixed power then your hull dimensions really matter.

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

> if you want more speed for a fixed power then your hull dimensions really matter.

So in other words there's no max speed since we're not talking about fixed power.

I’m not sure I understand.

Power isn’t what’s important. It’s power per volume/weight. If you have an infinitely dense power source then you can send matter at the speed of light through any medium. Is this really an important point to make?

Edit: Oh I see what’s going on above in this thread. It’s nuanced but I believe the original point was that in the Real World with Real Power Sources you have a Real Top Speed. You can’t just always dump more power into your ship to increase it and the right way to increase the max speed is to control hull dimensions.

It's a well known property of boats. Due to fluid dynamics. This is why boats are big. Longer the waterline the faster it can go. Also why fast boats use multi hull designs.

> This reads to me if I could get a Nuclear Fusion reactor in my ship that has 10 times the power my Max Speed would still be the same.

Hull speed is a pretty simplistic approximation of the actual physics behind it, but generally the rule holds: A displacement hull cannot exceed its hull speed. What will rather happen is that the bow wave will pile up and eat your energy. It’s actually a problem if a very powerful boat pulls a smaller one, the bow wave on the smaller boat piles up, making the smaller boats bow rise up until the stern slips under the water and it sinks. (Or something else gives in under increasing strain before that happens)

Now, other hull forms can be built: glider hulls for example that glide on the water surface (think fast sports boats etc.), but scaling those up will certainly be problematic if you’re trying to aim for high carrying capacity. Cats/Multi hull designs sort of cheat the physics: the determining factor is roughly the length of the water line and multi hull designs obviously have more waterline for a given total length.

One of these ships could maximally transport about 100.000 people a year. 50 million cross the Atlantic per year, so you are looking at having 500 of them, probably more when you take into account that they won't be in service 100% of the time.

OTOH if it took 3 days probably a lot of people would just stay at home.

I personally would love to see the return of viable long distance semi rapid ocean. With the Advent of high speed and low latency satellite internet, a 3 day Atlantic crossing sound like a wonderful break. I already love traveling by train and I've taken numerous 3 day train trips accross the United States.

> a 12,000 page technical application

I wonder if there’s a bike shed anywhere in there? If so, it’ll be more than a year to review.

Idaho and the surrounding area already has cheap power... and it’s about to get cheaper!

Come on California. Get your act together.

But the company has already secured permission to build its first 12-reactor plant at the Idaho National Laboratory, which may start supplying power to communities in Western states as soon as 2026.

Good plan. That's where to put it. The Idaho National Laboratory, formerly the National Reactor Testing Station, is 890 square miles of mostly empty space. For good reasons.

TIL about liquid metal cooled nuclear reactors. Wikipedia makes lead-cooled reactors sound pretty amazing, and yet lead-bismuth seems to be preferred, presumably simply because of the lower melting point, despite the disadvantages of bismuth (polonium byproduct, high cost). I'd be interested to hear if there are other reasons pure lead cooling isn't being more actively pursued. Especially for small, single-use reactors, it seems like it would be perfect.

Lead has some nice benefits:

Provides shielding or reflection (depends on the reactor spectrum)

High boiling point

Doesn't have the same chemical reactivity as other liquid metals like sodium or NaK

But, it needs to be balanced with the drawbacks:

High density. Liquid sodium is less than a tenth of the density of liquid lead. This becomes more of a problem the larger the reactor gets due to seismic loading.

Poorer heat transfer qualities than sodium (which is why liquid metals have mostly stuck to sodium)

Must be designed to flow with low velocities due to corrosion/erosion*

*This can drastically affect the size of the piping or flow passages required for cooling. Flowing above a certain velocity will erode and destroy pumps, piping, etc.

A low performance reactor won't be as highly impacted as a high performance reactor that needs to flow as much coolant as fast as possible. The Russians have done a lot of work in this area.

Hum... All those drawbacks are things that improve at least linearly when you reduce the reactor size and power.

Looks like lead would be a great option for those small reactors.

The reactor is difficult to turn off:

https://en.wikipedia.org/wiki/Alfa-class_submarine

>The issue was that the lead/bismuth eutectic solution solidifies at 125 °C (257 °F). If it ever hardened, it would be impossible to restart the reactor, since the fuel assemblies would be frozen in the solidified coolant. Thus, whenever the reactor is shut down, the liquid coolant must be heated externally with superheated steam.

Well, sounds like it's difficult to restart actually.

Which makes it difficult to turn off if you would like to restart it.

Yeah, those Soviet lead-bismuth reactors were basically single-use devices - once they ran out of fuel, they were useless and had to be replaced with a new reactor. I don't think Russia had any plans on how to safely decommission and dispose of them at the end of their life either.

If you're interested in a more modern Russian lead reactor, check out: https://inis.iaea.org/collection/NCLCollectionStore/_Public/...

They also have a lot of recent experience with sodium fast reactors, of which the BN-600 is still running, BN-800 is running (and was started within the past 2 years), but the BN-1200 is delayed:

http://fissilematerials.org/blog/2019/08/the_construction_of...

And the presence of bismuth means the coolant becomes contaminated with polonium, a very nasty alpha emitter.

Hot molten lead eats structural (stainless) steels for breakfast. If you get the redox chemistry just right, a thin protective oxide layer forms on the steel surface, but it's tricky to maintain in a vessel with flowing liquid.

The Russians in their Alfa submarine IIRC had some mechanism for dissolving lead oxide into the coolant under way. The Swedish company Leadcold has a process to produce a protective alumina layer on the surface, remains to be seen whether it works out.

On Netflix there is a three part documentary about Bill Gates. One of the parts is about him funding a new generation nuclear plant.

Too bad he was working with China. I want it to succeed but I imagine it cannot in the curent political reality (trade war, Xi, HK, Taiwan independence, etc).

The major setback highlighted in the documentary was Fukushima, which predates the recent political climate.

I thought I recalled that the major setback was the current U.S. administration's trade policies with China. Everything was set to go, but then the plans got trumped.

You're right :-). They were both addressed in the series (part 3).

> [~27:24] Narrator: Bill and his team finally believed they had developed the ideal energy source. A reactor that was clean, efficient, and most importantly, safe.

> [cuts to conference room TV playing Fukushima news coverage] ...

> [~28:22] N: Public opinion, already skittish, turned against nuclear.

> [cuts to the two walking around outside]

> N: When you have a massive setback, how do you deal with that?

> ... [some cut to old DOJ drama] ...

> [~32:07] TV anchor: The US nuclear industry is bracing for a backlash

> [background switches to Fukushima footage]

Later:

> [~41:49] N: In 2015, President Xi came to Seattle and had a private meeting with Bill.

> Some guy: Then we see real movement.

> ...

> [~42:39] TV: A tariff tit-for-tat, teetering on a trade war ...

> [~42:50] TV: Investment restrictions on China with respect to high technology.

> [43:09] Guy working on the reactor: China and the United States had to negotiate this very complicated contract. Well, each government had a right to cancel it, and our government did. So, by canceling that contract that gives us the legal right to do nuclear things in China, we can't do it anymore.

> [43:35] [cuts to another guy] N: What was his reaction when you showed it to him?

> Guy: I think he just said, "oh shit."

> [cuts away to more DOJ stuff]

There's got to be other options for hosting (locating) their work. I hope their lobbyists are pitching to DARPA and DOE as a way to reduce our stockpiles of waste. An alternative to Yucca Mountain.

I wholeheartedly support traveling wave reactors. Mostly as a way to reduce our stockpiles of waste. Energy generation is a nice side benefit.

I'm now unclear if Gates funded TerraPower is still working on TWR (or some variant).

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

FWIW, I oppose creating any new nuclear power facilities using any other technology. Excepting maybe pebble bed. Until the problems of proliferation, disposal, financing, incompetence, and corruption are addressed.

Great, except those aren't the problems facing nuclear. The issues are cost and public perception. Reactors are already exceptionally safe compared to fossil fuel plants. People don't like nuclear and even when they do they don't want it near their home. This has resulted in among other things an absurdly expensive and drawn-out process for getting approval to build a new plant.

The hope is that small reactors are cheaper to produce and maintain.

Also, can you give more detail on why you think regulation is so over the top?

In short, deliberate regulatory obstructionism. Telling people you'll protect them from nuclear meltdown is a great way to get votes. Estimates for the cost of nuclear energy without the past four decades of anti-nuke activism are as low as 10% of current costs.

https://www.mdpi.com/1996-1073/10/12/2169

If these proliferate how do we deal with fuel being stolen and used by terrorists or similar? I don’t know how realistic a dirty bomb scenario but right now nuclear fuel is tightly controlled in a small number of locations. With these reactors it would spread out into more locations and potentially into countries that don’t take maintenance and disposal seriously.

I think that if dirty bombs were a real threat, we would see more of the people who would want to use them doing more traditional bombing first/now, and bomb attacks are extremely rare.

I think this is perhaps more movie-plot threat than real risk.

Extremely rare in the west in 2019. Not rare in some other parts of the world with an unstable security situation. They were also common in the UK in the 90s and earlier during the troubles, so it's not like western countries are magically immune from instability.

Given that ordinary materials like fertilizers have been used to create bombs, I would say that the mass availability and distribution of nuclear material creates a near certainty that it will end up in the wrong hands sooner or later. And it's a problem because that means that each and every micro reactor will need to have very strict and expensive security. The security cost alone makes this a non starter compared to using batteries and solar. We already have those all over the place and it's not a problem. Also theft is going to be an issue. If micro reactors fit on a truck, those trucks could be hijacked. Or a deployed unit could be stolen. So, yes, I would say this is a show stopper.

Require long lead times for planning and coordination, ensuring that they would almost certainly be caught before using them.

As for dirty bombs, the mafia takes low-grade radioactive waste and dumps it in the ocean.

https://www.theguardian.com/world/2009/sep/16/shipwreck-wast...

Maybe nuclear reactors will be easier to deploy in China, where the government has more control: https://twitter.com/sampenrose/status/1162772916125126656

I won't be happy until I can have one of these in my basement.

It's about time at least some people are becoming sensible about nuclear and dropping the "boogyman" attitudes towards it.

Awesome. Nuclear is a necessary step as we move away from petro-energy.

Nuclear is not necessary. It's not even clear if it's even useful for that.

Too “bad” it will be economically uncompetitive compared to next generation wind and solar.

Wind and solar produce variable power sources.

Power for baseload has a 99.99% uptime requirement.

The batteries needed to make variable power sources even 95% capable of meeting demand are economically unfeasible as well.

As a couple examples.... The laegest solar plant in Arizona produces only 10% of its peak summer power in the winter. ...similarily, in Texas the wind turbines are usually not turning during Texas peak demand because it's during high pressure systems where there's not wind.

the problem with wind and solar is not 99% uptime requirement. it's always sunny somewhere or windy. it's not like at one point in time the whole world will be covered in clouds with no wind at all.

the problem is distribution the power over long distances.

That's kind of the "same" problem given we are not going to ditribute power of solar provenance by traveling half the earth. Likewise for wind: the distance are enormous to get reasonable wind diversity. So in practice it is not sure it is even possible in some (most?) regions of the world.

well it would be, if countries would see a need other than making money. but unfortunatly energy is something where everybody wants to make some money. also regions which are very unstable have a lot of sunpower. it's not easy to build reliable sunpower plants there.

and there is no grid available that spans the whole world. that would take a huge amount of work for all the countries, but countries do not think global, so it would be a pita to get everybody on the same feets.

Nuclear power has a capacity factor of ~80-90% [1]. What is the 99.9% requirement?

[1]https://en.m.wikipedia.org/wiki/Capacity_factor

In most cases the downtime is scheduled and can be prepared for.

Which means that already more expensive "baseload" plant needs to recoup the investment on even fewer hours per day. Especially true for plants like nuclear which at least for todays generation aren't good at load following.

There is only one constraint for the electric system: the power produced needs to exactly match the power consumed at any point of time. If you mismatch those two numbers, the grid is going to fail. The baseload is just the number for the power under which the demand never drops in a giving time frame, typically 24 hours. The other number would be the peak load, which is just the maximum load in that timeframe. The actual load will be between these two numbers and at any time the constraint named applies.

So "baseload" isn't some expecial part of the electricity. It is an accounting number. The challenge is to provide the correct power to the grid and for that, different technologies are used. Coal and nuclear power plants have a reasonably high availability, but as others have written, far away from 99% uptime. Their downside is, that their output can only be regulated very slowly. Both properties made them ideal for the amount of power which is called baseload. The problem is, they can't deliver much else due to their limitations. That is also the reason, that for decades the architects of the power systems tried to drive the baseload up. To increase demand at night, Belgium installed floodlights on their freeways, Germany for a while pushed electric heaters which would draw their main power at night at a reduced price.

Solar and wind behave inverse, they might not be as reliably available, indeed the sun doesn't shine at night, but they can be switched off in an instant. But any time they produce enough electricity, they can carry the baseload. So currently in Germany wind easily provides large parts of the baseload (https://www.electricitymap.org). Coal plants are almost shut down, even solar right now produces as much energy as coal.

So without coal and nuclear, the challenge still is to match the grid demand. This is independant from the baseload number. And with the shift to reneweables, the baseload number can be driven down quite considerably, if incentives are given to use electricity in times of high supply.

Wind and solar won’t do it alone but I think it will become the primary energy source for electricity production.

It probably will be supplemented by natural gas, coal, oil for the foreseeable future. These source have much less capital requirements and much better understood than novel nuclear energy; in a world where renewable energy just gets cheaper and cheaper the big capital spend of nuclear just does not make any sense.

> The laegest solar plant in Arizona produces only 10% of its peak summer power in the winter.

Nuclear also requires 12-18 month cycles of refuelling, not to mention malfunction downtimes. These requires several weeks: https://www.eia.gov/todayinenergy/detail.php?id=1490

For baseload, I'd rather vote for a compact Tokamaks: https://www.tokamakenergy.co.uk/st40-has-been-rebuilt-and-su...

Please stop repeating that baseload marketing line.

https://skepticalscience.com/print.php?r=374

Summary

Arguments that renewable energy isn't up to the task because "the Sun doesn't shine at night and the wind doesn't blow all the time" are overly simplistic.

There are a number of renewable energy technologies which can supply baseload power. The intermittency of other sources such as wind and solar photovoltaic can be addressed by interconnecting power plants which are widely geographically distributed, and by coupling them with peak-load plants such as gas turbines fueled by biofuels or natural gas which can quickly be switched on to fill in gaps of low wind or solar production. Numerous regional and global case studies – some incorporating modeling to demonstrate their feasibility – have provided plausible plans to meet 100% of energy demand with renewable sources.

> The laegest solar plant in Arizona produces only 10% of its peak summer power in the winter.

Daily insolation in Arizona varies by less than a factor of 2 from June to December, so I call BS on this statement.

This is the Wikipedia page for the largest solar plant in Arizona, and the 10% claim is clearly falsified by the numbers given here:

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

The US used 3,911 TWh in 2015, or 10.72 TWh per day. Base load is about 40% of daily average.

Assume the worst case of only solar- that baseload also continues during the day, so about 30% of it would be powered by solar. That leaves 28% of average load that would need to be supplied overnight, or 3 TWh for the entire US.

The current installed cost for grid scale batteries is <$500[1]- $483/kWh for the 129 MWh battery in Australia. Batteries in cars are <$200 at the pack level. At $500/kWh that's 1.5 trillion for the entire US. Well within manageable for several years- far less than has been spent on Iraq, for example.

There are many reasons to believe that batteries could easily last for tens of thousands of cycles if properly specified[2], but current batteries are specified to ~5000 cycles to 80% degradation. Adding 20% capacity every 5000 cycles would cost 6 cents per kWh of system throughput.

By comparison, the EIA says that Nuclear costs 8 cents per kWh today[3]. By current measures battery storage is cheaper than nuclear (not counting initial generation), and that's not even counting the massive reductions in capacity that would be enabled by other generation and HVDC transmission.

> As a couple examples.... The laegest solar plant in Arizona produces only 10% of its peak summer power in the winter.

That's a lie. The lowest winter output is 37% of peak summer output[4]. The variation is HIGHER in the summer than the winter; +55% in summer and -45% in winter. Power consumption in Arizona also varies at the same time (because that's how the plant was designed to produce power) by 25-30%, so the majority of that variation is simply proportional to normal load.

[1]: https://www.theverge.com/2019/6/25/18715585/tesla-australia-...

[2]: http://jes.ecsdl.org/content/166/13/A3031

[3]: https://www.eia.gov/outlooks/aeo/pdf/electricity_generation....

[4]: https://en.wikipedia.org/wiki/Mesquite_Solar_project

Smaller, safer, and just as friendly to centralized top-down control by governments, utilities, and mega corporations. Unlike solar which can be controlled by yourself on your own property.

It’s not an either / or. Nuclear makes a good backfill for the variable output of solar and wind.

Sort of agree. But unfortunately as a taxpayer or ratepayer you still end up sharing the cost of centralized boondoggles when they happen. Less so with decentralized elements of the system.

Nuclear is not that expensive over its entire lifetime though, the biggest issue (aside from safety and security concerns) is the huge up-front investment. In theory SMRs improve that significantly by providing smaller self-contained units which are easier to reclaim (unlike a traditional power plant site which can't really be reused even if you decommission it).

People try to point to operating cost once the investment cost is amortized, but that's only relevant for the decision of whether to shut down an existing nuclear plant. The fully loaded cost, including the cost to build and finance the plant, is the relevant figure when deciding whether to build a new nuclear plant.

And even on operating cost, many nuclear plants in the US have failed to be cash flow positive in recent years, and have been shut down before their end of their lives. The remaining reactor at Three Mile Island had not made an operating profit in six years before it was ended.

I think there may be some clever accounting going on if it’s claimed to not be that expensive. Example, the carbon offsets that should be required for for the concrete typically used in a large plant are never spoken of. And cleanup and disaster recovery costs are probably tucked away somewhere else or even far off the balance sheet, out of sight.

They used to say nuclear energy would be “too cheap to meter” and if that can come to pass (safely) I’m all for it but the accounting has to be done honestly.

Does it? I'm trying to think what the poison transients would be like on a core of that shape and size... In any case, I know that large commercial plants have transients that all but preclude the use case you're suggesting, since the daily periodicity of of the demand variability is much shorter than the poison transients.

Nuclear makes a terrible backup to wind/solar. They aren't compatible. The problem is nuclear needs to generate most of the time to make economic sense. That's not a backup source, that's a baseload source.

Sounds like we need this: https://en.wikipedia.org/wiki/ELENA_reactor

Or these: https://www.nasa.gov/directorates/spacetech/kilopower

But one has to be wary about the gap between reality and institutional or governmental propaganda (I’m looking at Russia but it happens in any country).

While rooftop solar does allow you to go completely off-grid, if you still want to have a grid around, it will have to be centralized. An underappreciated aspect of power grids is just how much advanced control is required to keep the entire thing stable and functioning, think armies-of-PhD's-difficult. When grids get too small, or don't have sufficient control (either knobs, or software/people turning the knobs), the results are frequent blackouts. Interestingly, the risk begins increasing again as your grid gets too large: you have too many knobs to reasonably control centrally, and it certainly won't work without synchronized control. As a case study, see how China is breaking up some of their huge electricity grids (in to still-large ~1000mile or so regions), as maintaining reliability and preventing faults from propagating across the country became too difficult.

Yes I agree, and thought I said nothing to imply that being on the grid is not useful, but maybe I could have made this more clear.

Na, you were fine, sorry if I came across adversarial. I just thought commenting here was an okay place to put my rant.

You don't need armies of PhDs to operate a nuclear reactor, just very strict procedures, trained personnel and military discipline.

I agree that a complex grid complicates things quite a lot. Just don't depend on the grid for anything, especially cooling a reactor after SCRAM.

> As a case study, see how China is breaking up some of their huge electricity grids (in to still-large ~1000mile or so regions), as maintaining reliability and preventing faults from propagating across the country became too difficult.

Have a source on this? IEEE says they're planning to merge the regional grids into a megagrid: https://spectrum.ieee.org/energy/the-smarter-grid/chinas-amb...

> While rooftop solar does allow you to go completely off-grid, if you still want to have a grid around

Why would you want to have a grid around?

Friends have been entirely off-grid in the Yukon for over 7 years now. They have a large, modern house with every convenience. Last time they tried to switch house insurance the insurance company didn't want to give them a policy because they don't have "stable" power supply.

My buddy replied by asking how many power outages the insurance person had been through in Whitehorse in 7 years (easily a few a year)... his off-grid setup has never had a single outage in 7 years.

So who has the "unstable" power supply?

>Why would you want to have a grid around?

Because vast majority of the world are and will be living in Mega Cities.

You need a pretty big property to be self sufficient, or a very reduced lifestyle. The typical American consumes about 10kW of primary energy at all times, on average. That's hundreds of square meters of panels.

And a small turbine and a wood furnace for heating.

No, just good insulation and a heat-exchanging ventilation system. See Amory Lovins's banana trees in Snowmass, Colorado.[0]

[0]https://mountaintownnews.net/2017/11/21/amory-lovinss-long-s...

That's super interesting for a 40 years old home, around here homes from that time sometimes don't even have double-glazed windows. It's too bad that there are no details being provided, but other articles[0] give more information and aside from the house being covered in solar panels it doesn't look too alien (save for the very bendy walls) at least until you find out the walls are 40cm thick and the greenhouse is absolutely integral to the concept.

I really like that the greenhouse uses permanent water fixtures (a waterfall, brook and pond) for both ambience and humidity control, I've been thinking about this sort of things and how to heat responsibly: mixed wood / pellet furnace was about my best idea, and apparently the Lovinses still have a backup wood-burning stove though their 2009 "v2" renovations allowed them to get rid of the gas-fired stove and heater.

One of the things which I find more interesting is how diametrically opposite they went for one of the directions: opening up the house using efficient glass panes, where I was thinking more towards burying it, in a more extreme version of turf houses. But that makes sense if you want to produce your own electricity using solar panels, you couldn't maintain a proper turf cover then.

[0] https://grist.org/climate-energy/amory-lovins-high-tech-home...

Your math is incorrect. 10k at all times per person x 2.6 people per household x 24 hours x 365 days would be 228k kwh per year per household.

In fact it's 10-11k kwh per anum. Many developed nations use 5-7k and don't live greatly reduced lifestyles.

http://shrinkthatfootprint.com/average-household-electricity...

It's hard to calculate the exact size due to multiple factors but the following source says a 2 kw system can use as little as 150 Sq feet. In some places you could generate enough to power your house in 3 hours or an American house in 6.

Presumably solar and power storage will keep getting cheaper. https://us.sunpower.com/blog/2019/07/16/how-much-solar-power...

I'm not talking about electricity alone, but about primary power consumption. That includes heat and fuel for your car, and also all the energy consumed by domestic industry. It's about 2.5155×10^13 kWh, or 81,800 kWh per person (in 2009)[1]. You're of course right that just electricity is much easier.

[1] https://en.wikipedia.org/wiki/Energy_in_the_United_States#Pr...

It's always a red flag when "primary" energy comes up. Something like 3/4s of that primary energy will be wasted as heat while being converted into useful energy, and so renewables have a 4x advantage just by their very nature of directly making electricity.

(They also have a 4x advantage even if generating heat is the actual purpose, but for different reasons.)

Sure, if you take that into account you still need several kW of average energy production. Unless you live in a very sunny area that's a lot of panels. Panels in Germany for example get about 10-15% of their peak rating if you average over the year.

Hah, no way. A little back of the envelope calculation shows that if that claim was correct, my electric bill would be 10 times higher than it actually is ($25 per person in reality, versus $250 per person in your world). Nope.

https://news.ycombinator.com/item?id=21788298

With great power comes great responsibility (to clean up the mess). One can have rooftop solar and live off the grid anyway, so what's the worry? It's not like the average Joe is qualified to operate a nuclear reactor in his garage, but we're getting closer with SMRs and micro reactors.

We could build these reactors underground in areas where there are not seismic activity. That would also protect the atmosphere should there be any kind of incident.

No, does make sense.

Going smaller will shoot the price through the roof. The basic convention is the bigger reactor you have, the cheaper it per unit of power output.

Nuclear powerplants suffer from high upfront costs that can be amortized if you mass produce the same model.

Then, you must mass produce the biggest type you can make.

In a market with strike prices and capacity markets this may not be a serious issue though. The best is the enemy of the good. Particularly when you are investor who wants to see a return within the decade.

That's totally backwards. The short version is that due to advances in manufacturing and metallurgy, there is no longer an advantage to scaling manufacture beyond a relatively small point. Economies of scale is not really a result of economic forces; it's dominated by engineering and other realities.

Look at how Alcoa revolutionized US manufacturing by making large numbers of small-scale rolling mills instead of large mills. Look at how the heavy press program[1] has fallen apart. Look at how large nuclear plants must now be made globally, because no single country can even come close to manufacturing the whole thing themselves.

Global manufacturing no longer has government investment driven towards the heavy presses required to create massive reactor vessels. Industries have figured out how to use welding, alloys, and smaller forgings to improve their products- both strength to weight and cost. Making big reactors nowadays is like an Apollo program, and subject to the same far higher one-off costs and inability to amortize.

[1]: https://en.wikipedia.org/wiki/Heavy_Press_Program

Wasn't the main issue with nuclear plants in the past that they failed in ways that were deemed impossible before they happened?

Not really. Chernobyl was explicitly known to have a vulnerability at a very unusual operating point. Fukushima was repeatedly flooded and officials refused to make protections against modest natural disasters. Three Mile Island was a mechanical failure.

There aren't many examples where something that went wrong was thought to be impossible. Much more often it is scenarios that were known to be possible, but ignored for reasons of cost or politics.

Nuclear plants are hardened against virtually everything. Certainly there may be things people haven't managed to think of, but there are many, many more things that we have thought of and haven't dealt with. A plant may be able to survive a bomb, but not a bunker buster or a full out war.

We don't want to and often can't ensure safety in every event that is thought of, which is why fail-safer designs are so popular in research and press circles.

It's a bit of an unfair rap since other thermal plants blow up all the time, dams burst, and windmills fall over. Radation makes everything more dangerous and has a permanent impact on our planet, but the actual rate of accidents is tiny. We do need more fail-safe plants (Fukushima in particular was inexcusable) but the real problem facing nuclear right now is cost.

Are modular nuclear reactors popular science's new flying car--one in every garage, arriving tomorrow?

Modular reactors have been on the horizon for at least 20-30 years. Large nuclear reactors aren't viable because of the immensely costly regulatory burden imposed by a fearful, democratic population. To focus on reducing costs without considering the reason for those costs seems naive. The fear is irrational. The population won't permit modular reactors anymore than they'd permit traditional reactors. Science, engineering, and reason don't matter. Necessity may matter, but the oceans may need to start boiling before people's fear of nuclear is overcome by other fears.

There are places where the local population consents to new reactors and then the projects still end up years late and badly over budget. SMRs wouldn't necessarily help to make nuclear-hostile regions more welcoming of reactors, but they might help builders to actually meet their cost and schedule estimates after they start building in a friendly region.

See these projects to understand why utilities in Western Europe and North America aren't ordering additional reactors recently, even in locales where the population already accepts nuclear power:

https://en.wikipedia.org/wiki/Virgil_C._Summer_Nuclear_Gener...

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

https://en.wikipedia.org/wiki/Olkiluoto_Nuclear_Power_Plant#...

https://en.wikipedia.org/wiki/EPR_(nuclear_reactor)#Flamanvi...

I live near an operating nuclear reactor. I much prefer it as my neighbor over a fossil generating station. But if it were put to a popular vote, I wouldn't support building a new reactor here because I don't want my electric rates to soar after the project ends up late and over budget.

Vogtle is a jobs project, an odd, almost absurd artifact of the high costs. I have family members working on that site. The Summer units across the river were canceled. Vogtle barely survived. The loss of Vogtle would have caused too much unemployment in the region.

I'd bet money the others are jobs projects, too, presuming they're still ongoing. But they'll be the last such nuclear jobs projects.

I hope modular reactors work out. I just don't think they'll work out in the U.S. or most other democratic countries, not until they're so well established elsewhere that nuclear becomes boring again. Failure to appreciate this--to shift focus to applications and regions where they have a viable, near-term future--will only ensure the total death of nuclear.

I had the same criticism for Rolls-Royce marketing piece last week about starting a modular reactor project in the U.K. I hope it works out, but Rolls-Royce claimed they were going to install the reactors in the U.K., which I believe is highly unlikely--certainly much more unlikely than if they attempted to first install them somewhere with less organized political opposition.

My complaint is that popular science pieces such as this Wired article create the wrong expectations. Articles about modular reactors are formulaic and periodic, exactly like articles about flying cars many years ago.

So about the opposition in the uk. When people talk about modular nuclear there is an expectation that it would be built close to towns and cities. That you could have one pop up down the road. I think this is unlikely for now in the UK. It is just easier and more economical to cluster them together onto a single site close to a large grid connection. This would probably be an existing nuclear site or power station site. A lot of these sites in the UK are being decommissioned anyway and are looking for new opportunities. This is much less likely to cause opposition than a new site on green field land (like fracking). And an existing nuclear site will have a local population that are more comfortable with the technology.

Think of the term "Economies of Scale." In one sense, it means building a larger steel mill, oil refinery, aluminum smelter, etc. to lower production costs. Applied to nuclear reactors, you get large, one-of-a-kind designs, that have to go through a long approval process, complicated construction, with major financial risk, defeating any economies of scale they had (primarily higher temperatures leading to higher energy efficiency.)

Another way to look at economies of scale is to produce a lot of identical widgets, in this case modular reactors that can be manufactured in one factory and shipped on trucks to the site ready to be installed, with streamlined permitting and approval based on a proven track record with identical units.

One additional benefit is you can do the site permitting "on spec" submitting for multiple locations and then you have 10-20 years to decide where you want to build, only investing the money if it turns out the market is there.

Well, it's our job as technically literate people to educate our friends and family about such things.

Although the article talks about cities, the early installations will probably be remote industrial sites like mines, where they're currently trucking in diesel fuel for generators.

For both, technology and price/perf is here. The society/regulators/coordination is the legwork that needs to be done now.

https://youtu.be/RYLGhVPp8lw

Agreed. Ironically, small reactors were all the rage in the 1950s [1]. As the Atomic Energy Commission struggled to find ways to make nuclear power economical, there was a conference of reactor advisory committee in October, 1957. They decided that the only way to make the most well-known tech (water-cooled reactors) economical was to scale them up, and how.

[1] https://whatisnuclear.com/img/aec-plan-1.png

Meanwhile, throughout the 1970s the combination of a large number of license applications plus an increasingly concerned public (now fully terrified of radiation from the nuclear weapons atmospheric testing debate) caused regulatory scrutiny to ratchet. Quality assurance, equipment qualification, inspections all became more rigorous. The Browns Ferry fire in 1975 made cable spreading rooms require 3-hour fire barriers and major redundancy. Rooms were added. More expensive materials were needed. Economic struggles continued. Then Three Mile Island happened in 1979.

In 1980, the viability of nuclear electricity was in question. Amazingly, the capacity factor of the fleet then increased steadily from 60% all the way up to 90%, making them profitable in the 90s and 00s to the point that a nuclear renaissance was set to occur in 2006-7, helped along by renewed concerns about carbon emissions. At the time, the US nuclear fleet produced about 65% of the nation's low-carbon energy.

But then the fracking boom happened. Low natural gas prices brought electricity revenue down in deregulated electricity markets, and the drop in revenue put many nuclear plants in the red. Utilities started replacing nuclear reactors with high-carbon fracked gas plants. Environmentalists didn't care much because solar costs fell 10x and wind was doing great too. Buzz about 100% renewable swept the nation as 10 GW of gas fire up every night in California.

Now, the nuclear industry looks back at small reactors, hoping the capital costs can be kept reasonable. It is indeed likely, that small water-cooled reactors using enriched fuel will be very expensive to operate, as they were in the 1950s. Many advanced reactor companies talk about using high-assay low-enriched uranium (20% enriched rather than 5%), which is economic bonkers. But enrichment and uranium are dirt cheap at the moment due to overcapacity from the Japanese and German nuclear shutdowns. This won't last though, and the HALEU reactors will very likely be too expensive to operate if they do actually get built.

The ML-1 military microreactor of 1961-65 was 10x more costly than fossil [2].

[2] https://en.wikipedia.org/wiki/ML-1

The most cost-effective thing the nuclear industry can do right now is invest in telling its story. Explain why it's an interesting power source. Explain the value in tiny footprint 24/7 low-carbon power. Most american don't even know that nuclear is low carbon. On the technical side, we need venues to try out some of the crazier reactors that may lead to real cost reductions in today's regulator environment. Put simply, this means we must build reactors that have only a tiny number of valves, cables, motors, etc. that are needed to safely shut down and cool the reactor. Low-pressure coolant reactors may be able to put this together, even though historically they've always been significantly more expensive due to the complexities of dealing with exotic coolants (liquid metals, molten salts, etc.)

In 1957, Walter Zinn (director of Argonne National Lab) suggested that liquid metal cooled (low pressure) natural uranium fueled (like a CANDU) reactors were most likely to succeed economically. They'd have low capital cost, very few safety-related systems, and would require very little fuel cycle costs. Today, I think there's a good chance that this kind of concept is still true. Could be molten salt or liquid metal at this point (molten salt reactors weren't really proven until a few years after Zinn's suggestion).

Good writeup. As a tech nerd, it's easy to get carried away with fancy things (breeders! MSR's! pyroprocessing!), but what nuclear really needs to succeed is driving down costs and improving public acceptance.

> Many advanced reactor companies talk about using high-assay low-enriched uranium (20% enriched rather than 5%), which is economic bonkers. But enrichment and uranium are dirt cheap at the moment due to overcapacity from the Japanese and German nuclear shutdowns. This won't last though, and the HALEU reactors will very likely be too expensive to operate if they do actually get built.

Hmm, sure, enrichment cost doesn't increase linearly as a function of enrichment, but it shouldn't be prohibitive either, particularly as fuel cost is such as small part of the total?

Of course, to get correspondingly higher burnup you probably need a new fuel design, and probably also burnable poisons, which will increase costs.

> Put simply, this means we must build reactors that have only a tiny number of valves, cables, motors, etc. that are needed to safely shut down and cool the reactor.

Isn't this what Nuscale is basically proposing (in addition to riding the SMR bandwagon, which may or may not work out)? Their design is cooled by convection, and can be indefinitely passively cooled after shutdown.

> In 1957, Walter Zinn (director of Argonne National Lab) suggested that liquid metal cooled (low pressure) natural uranium fueled (like a CANDU) reactors were most likely to succeed economically.

Interesting, got a reference? I couldn't find anything via some quick searching.

Though 1957 was also before centrifuges drove down enrichment cost, so the benefit from low enrichment isn't as great today as it was back then.

> particularly as fuel cost is such as small part of the total?

The current nuclear industry says things like: "Fuel is free!" all the time, and it nearly is. At EDF's fleet, fuel is something like 5% of the total cost. But this is in a world where capital costs have soared. If we're not careful, we can easily make fuel not free. Many advanced reactor companies are running too far with the fuel-is-free mentality and making choices that will inevitably challenge their long-term goals from a fuel cost point of view. Burning HALEU is a perfect example of this, as if you do that, especially in a fast reactor where you need high fissile concentration, you can make fuel more than 50% of total costs. If nuclear scales 10x or more as we need it to for climate change mitigation, the fuel-is-free mantra will break down.

> Isn't this what Nuscale is basically proposing

Pretty much. They're onto something for sure, as far as light-water reactors go. It will be interesting to see how much safety-grade equipment they end up with as the licensing continues.

> Interesting, got a reference? I couldn't find anything via some quick searching.

Page 413 of Hewlett and Holl's Atoms for Peace and War: https://www.energy.gov/management/downloads/hewlett-and-holl...

> Burning HALEU is a perfect example of this, as if you do that, especially in a fast reactor where you need high fissile concentration, you can make fuel more than 50% of total costs.

The way I think breeder might make sense today for a new commercial design (without a government funded reprocessing program) is if you have a design with a breeding ratio slightly over 1 enabling very high burnups without reactivity swing (iso-breeding, breed-and-burn, or whatever you want to call it). Of course, that requires a fuel design that won't fall apart at high burnups. IIRC EBR-II metallic fuel reached up to 200 GWd/tHM, and of course fast spectrum molten salt designs like Elysium have no such limits at all.

But yeah, for thermal reactors with no plans for reprocessing, much higher enrichments than the current LWR standard is most likely not justified, in my non-expert opinion.

> Page 413 of Hewlett and Holl's Atoms for Peace and War: https://www.energy.gov/management/downloads/hewlett-and-holl....

Thanks, looks like an interesting book (though not really much details why Zinn thought the way he did..).

> The population won't permit modular reactors anymore than they'd permit traditional reactors

I'd much rather a smaller nuclear plant per every few square miles that isn't vulnerable to meltdowns than large nuclear plants that are more complex and susceptible to meltdowns that will destroy all adjacent land.

And to say the fear is irrational is ignorant to history.

" Small Modular Reactors may be the nuclear industry's answer to avoiding obscurity, sadly, and one cannot blame them (though I am starting to) for failing to exhibit the courage or desire to commit attention to molten salt research. Because what is being presented by default is a practical absurdity.

What if someone promoting utility wind approaches you and claims that wind is the future? BUT in place of today's standard size 3MW turbines it absolutely must be a far greater number of 1MW turbines. You'd take a step back, confident that the reason must have little to do with technology. You'd feel dubious, imagine you were being 'played' in some way. Even a layman would sense something wrong with the proposal, given the overhead of placing units.

I have the same reaction when hearing discussion of Small Modular Reactors. I see them as a high ticket luxury item that is being fronted as the 'stealth solution' to a most pressing problem, to design something faux environmentalists and radiophobes might fear and hate less, even though they could never launch the nuclear industry into a new renaissance. Utility scale electric is geared to multiple ~1GWe+ solutions per plant, the round number that could practically be multiplied into a feasible grid solution.

Aside from industry desperation I also wonder if SMRs are being promoted by a few billionaires, not from a desire to supply lesser developed countries (all of whom should never go in for less than 1GWe), but to power their own offshore enclaves, their survival retreats in places like New Zealand. Call it my pet conspiracy theory. They wish to see the technology put to practice on our collective dime as soon as possible. Helping to stock the pantries of billionaires may be a tidy business some day but SMR fixation today represents a foolish diversion of attention away from what needs to be the principal goal --- attaining energy self-sufficiency for the grid with >=1GWe sources, less fuel volatility and less risk. This is an existential crisis. "

(from my 2017 letter to Energy Secy Perry)

https://archive.org/download/20170629EmailToEnergySecretaryP...

(2016 letter to Candidate Trump on Energy)

https://archive.org/download/20160422TrumpEnergyLetterSC/201...

Is anyone going to comment on my capitalization of the word 'but' for emphasis in the above quote? This place is starting to annoy me.

But others remained unaware of the invisible dangers around them: soldiers lounged in the sun close to the reactor, smoking cigarettes and stripped to the waist in the summer heat; a group of KGB officers arrived in the zone incognito, clad in tank crew overalls and carrying expensive Japanese-made dosimeters—but approached the ruins of Unit Four without knowing enough to turn the devices on. Only the fate of the crows that had come to scavenge from the debris but stayed too long—and whose irradiated carcasses now littered the area around the plant—provided any visible warning of the costs of ignorance. (Higginbotham)

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