Making Nuclear Energy Smaller, Cheaper And Safer | Hacker News Reader

Making Nuclear Energy Smaller, Cheaper And Safer

npr.org

99 pointspseudolus113 comments

Their webpage [0] has the construction cost at $3 billion for a ~700 MW reactor. This is about the same as the originally projected cost for the Flamanville EPR with 1600 MW, which now is expected to end up costing ~$10 Billion. Now even if we assume - and thats a big assumption - they really can build the reactor for $3 Billion, that still equals ~$7 Billion in construction costs for a Flamanville sized reactor.

They do not put any number on their operating costs which makes it impossible to calculate the electricity price they need to break even. If there is any information out there it would be appreciated.

[0] https://www.nuscalepower.com/benefits/cost-competitive

That $3 billion cost estimate is for first-of-kind of a reactor/plant that is intended to be replicated many times. The cost per plant is expected to drop significantly with total number of deployments. Also the plant is designed to have significantly lower operating costs, shorter construction time (which means shorter loan duration, lest capital wasted on interest). The Olkiluoto 3 (EPR) power station in Finland has been under construction for nearly 15 years! 15 years before you can even start paying off even 1 penny of the capital cost is a huge barrier overcome here with Nuscale.

I know, but they said the same about the EPRs, so I remain sceptical that it will work that way. Solar,Wind,Batteries,Hydrogen Production,Synthetic Fuel Production is becoming cheaper year by year so Nuscale need not only to meet their initial targets and then decrease the cost for future reactors but they also need to end up beating the other technologies costwise & safety & safety perception wise. Their Design might be faster than requiring 15 years, but I doubt it is as fast to build as solar or wind.

>They do not put any number on their operating costs which makes it impossible to calculate the electricity price they need to break even...

You can kind of get an idea though, if you know a little about the industry. So we know each one of their modules will need to be refueled every 2 years. That's one cost, and a major one, that we have a pretty good idea of. We know that the design, (again according to the salesman), does not require renewed water for cooling. That's a not so major cost that we don't need to worry about. Etc etc etc.

But yeah, at 720 MWHe and refueling every two years, that's enough to tell you that it's obviously not cheap. It's more accurately characterized as cheap-er than current designs.

My own guess, build price once they get the build process down will come in right around 6 Billion. The first one will end up costing way more, but I do believe the price will come down provided the "modularity" boast is at all true. (6 Billion sounds expensive, but it's a major upgrade from the, so far, 28 Billion that has been spent at Vogtie for instance.) Expenses related to refueling are going to kill you, but hey, it kills you for a normal reactor in any case.

So yeah, obviously this thing won't be beating out wind any time soon. But it is wayyyy cheaper than nuclear is currently. If you're a poor area, Wind with some innovative pumped hydro storage designs seems like a better fit for your pocketbook. But if you're a area flush with a lot of cash, some of these may work out for you. They're definitely what you might call luxuries. They're future is, basically, to be used as ultra expensive storage solutions for wind. So over service lifetime, I'd suspect wind/pumped hydro to be much less expensive. (Plus, who knows what will happen with other storage tech development in the interim?)

The great irony here is that the places flush with the most cash, Texas, Cali, New York, Minnesota, etc., are also the places least likely to use this. The places with little cash, your Iowas, your Wisconsins, aren't likely to use it either because obviously wind/pumped hydro is cheaper for them long term. (And wind/gas or coal is acceptable to them as a transition tech.) They wouldn't have had the money anyway though, so no real loss there.

Upper middle class states not close to the Great Lakes might be your best bets? Georgia? Utah? Etc. It'll be a tough sell. But if they find the right marks, they can probably sell it.

I have a hard time accepting their premise that they are designing for "cheaper" based on that artists rendering (which I assume is based on some real design elements). Curvy roofed buildings and arced cooling ponds are not at all the most cost effective construction methods.

I want truly cheap nuclear that sits in unobtrusive cheap concrete boxes like the old Bell telephone exchange buildings.

The issue right now is every plant is a unique one-off. Meaning the inspectors need to pour over the plans, construction crews need to learn how to build each design specifically, fabricators providing parts need to make each plant's run of stuff special. If we could have just one standard nuclear plant design, even if it was silly curved roofs or whatever, it would massively decrease plant construction costs by taking advantage of standardization.

France did this in the 1970s. They hired engineers to design them 1 single kind of plant that was cheap, safe and would last a long time and then they pumped them out by the dozens. Every plant was the same as every other plant, so construction crews got good at it, part manufacturers could tool up for big production runs and lower per-part cost, and government inspection was drastically simplified because everything on the project was as stock as possible and the original design had already been approved. Now France's problem is it has too much electricity, as it over-estimated how much energy demands would ramp up going into the 21st century, and so now sells excess wattage to Germany.

>Now France's problem is it has too much electricity, as it over-estimated how much energy demands would ramp up going into the 21st century, and so now sells excess wattage to Germany.

Um, that doesn't exactly sound like a "problem", especially since Germany gave up on nuclear due to nuclear fears, and still has a lot of coal plants.

It's a good problem to have but it is still a "problem." Nuclear plants have huge fixed costs in security (due to international treaties and so on), even if the reactor never runs, let alone the cost of operations and maintenance, so if you overbuild, it drastically increases your energy prices due to the ratio of fixed costs to production - unless you can sell enough electricity to other countries to make it economical for your own population.

Pore not pour

To much energy is the central problem with nuclear. It’s capital intensive so if they don’t operate 24/7 their cost per watt increases. This puts Nuclear in a bind as wind and solar are both significantly cheaper and Nuclear is terrible as a peaking power plant.

In the end it needs to either beat Wind or Natural Gas. Meanwhile grid storage prices keep dropping which may soon start undercutting Natural Gas.

No, it is meant to beat base load plants, that is oil, coal, natural gas, biomass, geothermal and hydroelectric.

Wind is somewhat bad as base load plant as there are serious lulls when wind is relatively globally low.

Base load power is inherently less useful than peaking power plants as the demand curve while predictable is extremely variable. Power companies build as many of them as they can get away with because they are cheap, not because there is some inherent advantage to steady state power.

Wind competes in exactly the same niche as the price is low though with some additional downsides. As you build more of them there is less utility in base load power as you end up producing wasted electricity production ever more frequently.

PS: Hydroelectric is generally the ideal peaking power plant as it’s cheap, the downside is you can’t build many if them.

> Hydroelectric is generally the ideal peaking power plant as it’s cheap, the downside is you can’t build many if them.

What ever happened to the offshore hydroelectric turbines we were supposed to get? I think is was 15-20 years ago they were being touted as one of the next big power systems.

The ocean is a really difficult place to leave equipment. Short term small scale tests looked promising, but scaling up never really worked out.

I think the artists were just told to make something that looks attractive for the public.

> Curvy roofed buildings and arced cooling ponds are not at all the most cost effective construction methods.

Just because the architectural facade is 'fancy' does not mean the internal plumbing is.

An arched construction can cover more area with less material and without internal columns; this was realized back in ancient Roman times. So curves may be there for a reason. (The pond is by an artistic license, without doubt, though.)

The important parts not on picture:

* Small reactors units, built on a factory and delivered by truck.

* Reactor units are unified, so the economies of scale kick in.

* Full passive cooling, sufficient when all external power is off.

* Containment vessels for the reactor units, so the danger of any leaks is greatly limited.

What makes me wonder is the complete absence of a smokestack to siphon off any excessive second-circuit steam. The artist also did not draw an electric switching / transformer yard and a power line. Do they plan electricity egress by some underground superconductive cable? (Would be cool, but not cheap; currently only makes sense in very dense urban environments.)

> "My concern about NuScale is that they believe so deeply that their reactor is safe and doesn't need to meet the same criteria as the larger reactors, that it's pushing for lots of exemptions and exceptions," says Edwin Lyman, acting director of the Nuclear Safety Project at the Union of Concerned Scientists

Bit of a red flag there...

Edit:

The article further states: > "Licensing this design is challenging. It's so different from existing plants that regulations must be changed to accommodate it. That worries some watchdogs and critics."

Let's not shoot the messenger here.

If they are regulatory requirements that clearly do not apply to this technology because, e.g. it does not use the regulated parts or technology then fine. But that should be very thoroughly scrutinised and no exception should be granted on the basis that it is safe on paper.

Many requirements are very expensive to meet so I would understand that a private startup tries to minimise the burden. But I think nuclear safety comes first.

Is there evidence of this actually happening?

Considering said Edward Lyman has made a career out of FUD'ing anything nuclear, I'd be sceptical of taking anything he says on face value.

Union of Concerned Scientists are an anti-nuclear lobbyist group. Anything they say should be dismissed out of hand. They have 0 credibility and have spent the last 50 years spreading lies and fear about nuclear energy.

The problem here is actually that the people at 'Union' are deeply convinced that nuclear is bad and no nuclear project no matter how much time was spent on safety has ever been endorsed by them. This is simply how they operate.

The reason there are 'exceptions' is because partly with the help of themselves the nuclear regulatory system was changed in a way to hardcore specific technological solution into the regulatory process that only work for traditional PWR, practically excluding every other form of nuclear energy.

NuScale uses PWR technology in a slightly different form but because that's what they believed to be able to regulated, but even that requires lots of extra cost to get regulated.

The regulatory changes after the nuclear accidents essentially killed all research and all progress. This can be seen both in the rates of new reactor designs and reactor building rates.

Union of Concerned Scientiests and Greenpeace have been at the forefront of this issue for a long time now, and their deliberate strategy since literally 50 years (and this is a fact that has been shown based on their internal documents) is to always focus on nuclear safety because that's how they can make it uneconomical. And to their credit, this strategy has worked perfectly. It might be the single most successful political campaign of the 'environmental movement'.

If they had been this effective against coal we would live in a better world now.

> Union of Concerned Scientists are an anti-nuclear lobbyist group.

Or maybe they are just concerned about a power source which has proved catastrophic multiple times in the past.

Compare the number of deaths due to nuclear accidents to the health effects of us all breathing in coal pollution.

Deaths / trillion kWhr (https://www.forbes.com/sites/jamesconca/2012/06/10/energys-d...)

Coal – global average 100,000 (41% global electricity)

Coal – China 170,000 (75% China’s electricity)

Coal – U.S. 10,000 (32% U.S. electricity)

Oil 36,000 (33% of energy, 8% of electricity)

Natural Gas 4,000 (22% global electricity)

Biofuel/Biomass 24,000 (21% global energy)

Solar (rooftop) 440 (< 1% global electricity)

Wind 150 (2% global electricity)

Hydro – global average 1,400 (16% global electricity)

Hydro – U.S. 5 (6% U.S. electricity)

Nuclear – global average 90 (11% global electricity w/Chern&Fukush)

Nuclear – U.S. 0.1 (19% U.S. electricity)

I've never been quite enthusiastic about these kinds of numbers, because I'm not sure what deaths are included. I believe this article includes indirect, pollution-related deaths for fossil fuels, but what about deaths in uranium mining and processing?

Forbes separates out the US numbers because of the strong regulatory regime here---which strikes me as odd; doesn't Forbes usually consider environmental and health-and-safety regulations bad?

One confounding factor in this data is the low numbers of large-scale accidents for nuclear power. The reason the hydro power number is so high is a number of very large dam failures; would nuclear numbers be similar if Chernobyl happened in a much higher population area or if Fukushima happened faster?

> but what about deaths in uranium mining and processing

Modern Uranium mining is basically pin-point mining mostly done by machines. And even without that, Uranium is so energy dense that you don't actually have to mine much. Every other energy source also has lots of mining simply because you need lots more of normal metals.

Think about the absurd amount of mining required for wind miles.

The same for processing, those are very highly advanced modern processes that are pretty strictly on safety.

There are very few deaths from either.

> One confounding factor in this data is the low numbers of large-scale accidents for nuclear power.

The only ever large-scale accident (in terms of people) for nuclear power is Chernobyl and if you look at the long term death we are talking around 4000 who die earlier and maybe 50 who died faster and that is one event 40 years ago.

Other then that there have been basically 0 deaths from radiation from civilian power nuclear accidents. In reality Chernobyl was a military reactor and shouln't even be included in the first place.

> or if Fukushima happened faster

I'm not sure what you are talking about here. It seems that you assume that evacuation saved people? That is totally wrong. Actually a far larger number of people died during the evacuation that were actually endangered by the radiation.

They are a lobbyist group they get their money from contributions by people who want to fight nuclear power.

> proved catastrophic multiple times in the past

Any evidence for that?

Although NuScale is not the first to focus on this type of implementation (Westinghouse, Areva, B&W, etc..), namely small modular reactors (SMR), I am glad to see more hands in the mix. As a South Carolina resident (and supporter of nuclear power) and witnessing the shit-show with SCANA and the cancelled VC Summer plants, I am hopeful that economies of scale can take effect in the SMR-based designs.

Is this economies of scale in the right place though?

I'm doubtful we'll ever get to the point where you can just plop a reactor down and go. You're still going to have the years of political wrangling, all the bulky containment and supporting infrastructure.

Most likely multiple units will be deployed on each site, allowing them all to take advantage of shared infrastructure like grid connections, spent fuel storage, security etc.

Yes I was going to add that their best chance is being put on the sites of old reactors.

I also wonder if converting old coal-fired plants is possible. If the turbines, generators, and the power distribution stuff is in place and in a good shape, maybe setting up an alternative source of steam could be more economical than building the whole thing from scratch.

Typical coal plants use superheated steam at around 540C and turbines designed for that, whereas LWRs produce wet steam at 300C, so no.

High-temperature reactors can produce superheated steam, but then it's not a LWR and you give up on all the knowhow how to run those. The Chinese are planning to deploy gas cooled pebble bed reactors which could replace the coal furnace at existing plants (HTR-PM).

Alt. take: one could not reuse the turbines, at least not efficiently. One might be able to reuse other parts of the steam/condensate/feed systems. The electrical systems could largely be reused.

I doubt that reusing anything other than the power distribution and cooling loops would be economical.

Don't forget maintenance stations and other office housing required to run the plant.

“NuScale's design doesn't depend on pumps or generators that could fail in an emergency because it uses passive cooling. The reactors would be in a containment vessel, underground and in a huge pool of water that can absorb heat.

That means that even a reactor that fails would still be safe. "It doesn't require any additional water," says Feldman. "It doesn't require AC or DC power. It doesn't require any operator action. And it can stay in that safe configuration for as long as is needed."”

What if there’s a leak? What if for some reason the temperature inside the reactor is slight enough to vaporise the water?

About the water vaporizing: I'm guessing the pool is so "huge" that the sheer amount of energy required to vaporize the water can't be found in the fissile fuel alone. That doesn't account for the possibility of a leak, though.

In an accident scenario, the heat that is problematic is not from the fissile material (i.e. U235, Pu239) but from the fission products' decay heat - the isotope soup remaining after the fissile atoms split. It is much less intense than the heat/energy produced during normal operation and drops off significantly after a couple days. So the pool's purpose in terms of accident mitigation is to keep things cool enough during the period of time after reactor shutdown and before radioactive isotopes left over from split atoms decay/cool-down enough.

While you are correct that it is less than the nominal heat output, we are still talking about 50MW a minute after shut down and 5MW one day after the shutdown of a 700MW reactor. So even a day after the shutdown you are able to boil of 2kg of water every second.

Yes, it is still a lot of heat. But to a lay reader, it might be easy to believe that the pool needing to be able to cool the reactor means that the pool has to cool an operating plant during an accident which is incorrect. I was just trying to make the distinction here. Also the drop from (your very approx numbers) 50 MW to 5 MW is mostly exponential - and so very quickly drops away from 50 MW. After that, any remaining heat is diffuse enough to not actually boil away water from the pool. Fuel-melting risk (which is not the chain reaction restarting for any who may be limited in fission plant understanding) is generally only a concern for the first couple days after reactor shutdown.

Funny little detail that might interest you: Due to the presence of a large number of different fission products (with different half lifes), the drop does not really follow an exponential but is better described by P(t) = P_0 * a * (t^-0.2), i.e. a power law, where P_0 is the power before the shutdown, a is a couple of percent and t is the time since the shutdown in seconds.

Leaks are designed out because the entire reactor vessels are surrounded by a giant swimming pool. The temperature stays low enough because this swimming pool is passively cooled.

Lack of relible decay heat[1] cooling caused both Fukushima and three mile island accidents. Having passive decay heat removal usually decreases the probability of core damage by about 100x.

1 https://whatisnuclear.com/decay-heat.html

"Having passive decay heat removal usually decreases the probability of core damage by about 100x."

100x isn't 100% though.

100 of these small reactors has the same risk as one large reactor. Perhaps higher, because like you, everyone goes around saying the risk has been designed out.

Though obviously one small reactor going boom is preferable to a big one doing the same.

100% safe is never the metric. Nothing is 100% safe. Every form of energy generation has risks that have to balance the good the energy source brings. Nuclear is nearly unique in that it can produce carbon-free energy (unlike fossil and biomass), continuously for 2 years on end between reloads (unlike wind/solar/coal), and it can be deployed in a wide variety of geographic locations (unlike hydro and geothermal).

The risk is that there are occasionally nuclear accidents: Three mile island and fermi 1 meltdowns, both of which killed zero people. Chernobyl, which killed ~50 from ARS and up to 4,000 early deaths over the next several decades (on top of a few million cancers that would have happened anyway in the population). Fukushima, which killed up to one person. Can anyone name any fatal natural gas explosions? Any hydro dam failures that killed 100,000? How many people per year does coal kill by operating normally (~200,000). We as a society accept certain risks from our energy infrastructure because of all the good we get from it.

Here is a plot of how many thousands of days of life are lost by various things [1]. Note that nuclear is almost ridiculously low. This chart doesn't include the impact of climate change on human lives. Nuclear fission is a climate superpower, and we cannot be justified in neglecting this natural resource because we're afraid of something going boom.

TLDR: A factor of 100x improvement in nuclear safety goes from tiny risk to supertiny. Current plants are already safer than almost everything else we know. Some studies have more people dying from installing solar on their roofs than getting killed by radiation from nuclear fission plants.

[1] https://i.imgur.com/ClgbpA4.png

Yeah, even Sun will blow and destroy our Solar system, so solar energy is not safe too.

BTW: Will you move to Chornobyl to demonstrate that radioactivity is safe? Land is cheap here.

Sure, if my family and job were there. Its a thriving wildlife refuge now. Check it out.

https://thoughtscapism.com/2019/05/08/worlds-worst-energy-ac...

I can drive to Chornobyl by bicycle. I just don't want that.

Wildlife is thriving in my area too, because people abandon homes and move to cities instead.

However, if you like it, you can create similar exclusion zone near to you. Just vote for nuclear power and wait until next nuclear disaster.

Come on. You can drive nearly to the reactor itself and not even get a yearly background radiation dose now. There are a few hot spots where contaminated gear from decommissioning is stored, that's it.

People got cancers at increased rate, which is limited to less than two generations of damage. The range had expired a bunch of years ago.

Going into high mountains is a bigger radiation risk today.

As a bonus, you can just drive to Fukushima on a bike today and not even get a daily dose of some inhabited places in the US.

Cancer rate continue to grow here at steady rate. My neighbors died because of cancer, my brother has tumor. Tell your nice story to someone else, please.

> However, if you like it, you can create similar exclusion zone near to you. Just vote for nuclear power and wait until next nuclear disaster.

Reminder that coal has more radioactive waste over a decade than a nuclear plant does in its worst failure mode; and that worst failure mode is very unlikely with modern reactor designs (unlike Chernobyl and Fukushima)

1) We are out of coal now.

2) All coal plants in the world combined cannot make land inhabitable for millennia.

A 1% failure rate is not acceptable.

Nice try downplaying the actual consequences of a reactor incident like Chernobyl.

Do I have to mention radioactive boars roaming in Bavarian forests again?

The billions in costs to an economy?

The only part I agree with you is that coal is a not an acceptable way to generate power.

There's now sufficiently cheap power generators that don't devastate whole areas for centuries to come. Let's use those instead of this old nuclear tech.

Core damage frequency of modern plants is in the 1e-6 to 1e-8 range/year. That's 4-6 orders of magnitude lower than 1%.

I highly recommend you read some recent info regarding Chernobyl [1]. I'm not downplaying it at all. I'm using quantitative numbers produced by teams of UN and WHO scientists.

RE cost: climate change will cost trillions. Nuclear power plants can prevent that cost.

"Centuries" is a persistent anti-nuclear myth. Again, see [1]. I don't think you're well justified in saying I'm downplaying Chernobyl when you're going on and saying stuff like this!

[1] https://thoughtscapism.com/2019/05/08/worlds-worst-energy-ac...

What happens if the swimming pool leaks ?

The pool only needs to function for a few days during/after an accident until heat energy from fission product decay reduces to lower levels. The pool's function is as an accident mitigation measure - and when any accident occurs the reactor enters a "shut down" state. The decay heat energy that needs to be dissipated is much lower than normal reactor operational power output.

I mean ... millions of people who barely maintain their homes avoid pool leaks, and when it does leak, it tends to be slow enough that they can call in a professional to fix the problem. Imagine a fastidiously maintained facility ... I think they can probably work it out

You have to consider stuff like terrorist attack and so on. Nobody is so incentivized in making your backyard pool leak.

What if a dam explodes? More people have died due to dam failures (both intentional and accidental) than have died to nuclear power, but there is nowhere near the freaking out over the safety of dams compared to nuclear power.

For comparison, the Banqiao Dam failure (the largest dam failure in history) killed as many people as the sum total of every nuclear power plant failure and every atomic bomb ever used, combined.

While dam break cost lives, there is crucial differences that are never mentioned by the pro-nuclear crowd on HN.

1.) Dam breaks devastate much smaller areas. So even if the human toll is the same, the amount of infrastructure lost is smaller.

2.) The area is unlivable (or even inaccessible) for a much smaller duration of month instead of millenia.

Maybe land lost "forever" (on the timescale of individual human lives) is not a big problem in some part of the world, but in densely populated areas (any they need the most power, so would have MORE reactors per area) you can not simply block off an area the size of Belgium because a reactor exploded. This makes nuclear power a lot less attractive in India, Europe or (coastal) China.

Chernobyl's exclusion zone was ~1000 mi^2, consisting of ~120,000 people. The Oroville dam evacuation zone is ~250mi^2 encompassing ~180,000 people. Floods are no laughing matters; the Chinese decision to break the levees of the Yellow River during the Second Sino-Japanese War is credited with killing 400,000 people or so and rendering millions homeless, and the land was unusable for the better part of a decade, not "a month."

> 2.) The area is unlivable (or even inaccessible) for a much smaller duration of month instead of millenia.

Millennia of uninhabitability is anti-nuclear propaganda. Most of the zone will be reinhabitable within a century of the accident, and much of it is already inhabitable again but still excluded out of safety margin concerns.

Strengthening your point on the persistent anti-nuclear "uninhabitable for millennia" myth, check this recent article out [1]. The wildlife at Chernobyl is thriving. There are far worse energy accidents in other industries that cause far more and widespread damage.

[1] https://thoughtscapism.com/2019/05/08/worlds-worst-energy-ac...

Chornobyl's exclusion zone covered small part of contaminated area only. My parent's home is in contaminated area, but nobody was evacuated. Cancer rate is 2.5x larger at average in four regions of Ukraine, which are near to Chornobyl. I saw 6m (20 foot) wide circle of dead grass at about 800m from my parents home, where a hot particle landed. Both my neighbors are died because of cancer. I live in clear region, but my lungs was very radioactive for few years, because of my visits to parents.

> Cancer rate is 2.5x larger at average in four regions of Ukraine, which are near to Chornobyl.

Citation needed. WHO says up to 4000 early cancer deaths total from Chernobyl. 2.5x larger cancer fatalities would be hundreds of thousands if not millions of people which is not seen by any credible study that I'm aware of.

My ex grew up in Gomel and didn't get cancer. Neither did her parents.

In Ukrainian. See graphic at page 235 (Thyroid cancer level growth since tragedy).

http://irbis-nbuv.gov.ua/cgi-bin/irbis_nbuv/cgiirbis_64.exe?...

My brothers were unable to escape. Younger brother had problems with thyroid, but survived. (I had problems with thyroid too, but at much smaller scale). Older brother had brain surgery about two months ago, but it's unknown is it helped or not yet.

Nuclear has the lowest deaths per petawatt-hour of any generation method: https://en.wikipedia.org/wiki/Energy_accidents

Lower than wind and solar.

Dams also protects people from floods, so they are net positive.

The pool, as far as I can tell, is built pretty sturdy. Breaking this amount of concrete takes a lot of high explosives, and breaking it underwater is an order of magnitude harder. The Allies at WWII had to go to a great length to damage German dams, while using multiple heavy bombers.

If terrorists were in possession of such amounts of powerful explosives, and a capacity to place them inside a highly guarded area, they could use that to blow up a city center to a much greater destructive effect.

It's not human action that would worry me, it's nature. Freezing cycles could easily erode a pool in a few decades and make micro-cracks that fester unnoticed for years. Rust is an ever present issue for re-inforced concrete and is the cause of countless civil engineering disasters.

Practical Engineering on Youtube is a great overview of the issues we humans have with water: https://www.youtube.com/user/gradyhillhouse/playlists

Of interest here are these videos:

https://www.youtube.com/watch?v=eImtYyuQCZ8&list=PLTZM4MrZKf...

https://www.youtube.com/watch?v=0EzoHXEzdwY&list=PLTZM4MrZKf...

https://www.youtube.com/watch?v=EACkiMRT0pc&list=PLTZM4MrZKf...

I hear what you're saying, but I think the point I tried to make in my OP is getting lost here ... in a (well run) facility such as this, nothing would fester unnoticed for years. Actually, I love that you posted some of Grady's videos ... it shows just how much knowledge we have around these problems. And yes, they're not easy, and they're not necessarily cheap to deal with ... but we can deal with them. It's a known problem.

Yes, but the expected value of harm from my backyard pool leaking is, well, I can't swim and I need to resurface the pool liner. Multiply this issue by the probablity that it'll happen at all, and you get, well, a filled pool to swim in.

But the expected harm from a SNR like this having a leak is decidely not the same. Yes, the leaks may be rare, but the outcomes from such a leak occuring have Chernobyl-like outcomes in their failure trees. The probability calculus still may return that this design is quite fine, given the risk tables, but you MUST run the numbers. Hand waving is not ok here.

What happens if a windmill explodes?

I'm not too sure but I can say for certain that it doesn't spew radioactive material into the environment.

There would be some trace amounts of radioactivity in the materials used. Probably not enough to harm the public.

Similarly, most fission reactor failure modes don't release harmful amounts of contamination to the public.

Some exotic runaway condition - not sure if generators can do that - electric motors if wired incorrectly self destruct in amusing ways.

More likely you have an over speed failure and the it runs out of control and self destructs flinging the blades and other heavy objects about.

https://www.youtube.com/watch?v=Q5COAi6KM8o

The pool won't normally be radioactive if I'm reading things right, so... nothing will happen. It's the backup for if the pods fail, not a primary line of defence.

Per gigawatt-hour, nuclear power as it stands may very well be the safest power source that we have got already.

The biggest hurdle is irrational fear and the regulatory barriers consequent.

Yeah, it's sad that people refuse to live at Chornobyl, Fucusima, or many other safe places. So much of land is just wasted because of this irrational fear.

I grew up downstream of a whole set of International Paper and Boise-Meade paper mills on the Androscoggin River. I think I'd prefer Fukishima - there's less cancer there.

I live near to Chornobyl. Many of us are died because of cancer, which is 2x-3x more common here, even when statistic diluted by clean areas. I can help you to move, if you wish.

I wouldn't necessarily call it irrational. While there are far less incidents in nuclear power, their severity and long term harm are much greater while being very hard to get back under control as we have seen in the past. I would assume many would prefer to have broken a bone a few times in their life instead of a single shot in the head. This fear is very much understandable in my opinion.

I do not mean to imply that there are less fatalities from other energy sources, especially since those harming the environment might cause the end of us all. It's much like the fear of flying, it is safer, but if something happens you cannot run nor stir to the side, you are completely of control and the outcome will be most certainly fatal.

> their severity and long term harm are much greater

This is false; Coal has more radioactive waste release to air, soil, and water. In the U.S. we store what we do capture in "ash pools".

So... following that logic, air travel is the safest method available, so your argument is that we should stop regulating it? It's the safest method available because it is well regulated with an attendant long-standing culture of safety -- so much so that even a single breakdown (c.f. the 737 MAX) is considered an existential disaster for a manufacturer.

For an argument from the other side: you're notably looking at (well regulated!) electrical industry statistics for your safety metrics, but if you include unregulated (military) applications things don't look nearly so rosy. There are a surprising number of reactors sitting on the bottom of the ocean right now...

A 1% failure rate is not irrational fear.

No, the biggest hurdle is that it's grossly uneconomic.

Because it costs billions of dollars to check everything over in octuplet and build everything special because everyone is so damned afraid of The Bomb that we gave up on building them fifty years ago at scale.

It's the safest thing going.

https://twitter.com/ShellenbergerMD/status/11255616735556935...

The nuclear industry isn't very good at making reactors, but they're really good at making excuses.

Complexity is the enemy of any reliable system. No energy source is simpler than solar arrays. They don't require any moving parts, thermal management, waste containment, or strong security. The only maintenance required is dusting. Why otherwise intelligent people cannot appreciate the cost of complexity for nuclear energy is beyond me, especially when viewed in contrast to something as simple as solar.

There are costs other than complexity which must be considered before selecting a power source. For example, energy density per unit area. Nuclear has a much smaller footprint. Also the cost, maintnence, lifetime, and environmental impact of batteries required during night time/occluded operation is also not trivial, as is accommodating for unpredictable outputs due to weather.

Agreed, Also diversity of power is a win. But I agree, with the OP comment here, the simplicity of Solar is hard to get past, but sometimes it just won't work for a given application.

Nuclear is slow to operate, so it needs batteries to handle peaks during day. Nuclear can provide baseline power only.

Solar panel can be installed at roofs, so it can double as shelter, and power loss due to transmission can be lowered. Backup gravitational battery can provide backup power on site for short (hours) periods of time, to cheaply offset energy from peak of production at noun to peak of consuming at evening. Efficiency of solar panels can be improved up to 80%, so they can reduce need for air cooling.

Except that solar doesn't provide power at night, and reduced power on some days. That means you need either storage or alternative power. Areas which can provide large amounts of solar tend to be located far from population centers. That means long range transmission systems, which are among the most complex systems in existence.

Or you could just overprovision solar.

"My concern about NuScale is that they believe so deeply that their reactor is safe and doesn't need to meet the same criteria as the larger reactors, that it's pushing for lots of exemptions and exceptions," says Edwin Lyman, acting director of the Nuclear Safety Project at the Union of Concerned Scientists.

Here's a picture of the setup.[1] The reactors all share the same pool. The pool is big enough to absorb the heat in an emergency, and passive heat transfer from reactor to pool is high due to a smaller reactor size, and all this passively prevents a meltdown.

So they have one class of failure covered. But that's not the only possible failure. Leaks into the pool become a big problem, because one reactor can contaminate the pool and all the other reactors. Three Mile Island had a valve failure and contaminated the containment vessel. That was expensive to clean up, and made the reactor useless, but didn't cause trouble outside the plant. A plumbing leak with NuScale could take down all the reactors.

[1] https://www.world-nuclear-news.org/Articles/NuScale-SMR-ente...

"The pool is big enough to absorb the heat in an emergency, and passive heat transfer from reactor to pool is high due to a smaller reactor size, and all this passively prevents a meltdown."

Out of curiosity, how is heated water circulated through the pool? I have this sudden vision of the reactor boiling the water around it and being surrounded by a pocket of steam. Or, the repeated formation and collapse of a steam bubble, which can't be good.

""My concern about NuScale is that they believe so deeply that their reactor is safe and doesn't need to meet the same criteria as the larger reactors, that it's pushing for lots of exemptions and exceptions," says Edwin Lyman, acting director of the Nuclear Safety Project at the Union of Concerned Scientists."

If it's safe, it should easily meet the criteria and so shouldn't need exemptions and exceptions, right?

The idea is to save on some costs of monitoring equipment and recertification per each module.

Good luck...

Although I'm not a big nuclear power fan for various reasons, I'm really happy to see someone approaching it with an eye to realistic safety, modern economics, and compatibility with a renewable-based grid. It'll be interesting to see if this can compete financially with batteries.

>> ... if this can compete financially with batteries.

I don't think there will be competition. With storage costs dropping I don't see why nuclear plants would be any different than solar or wind. If solar+wind can cover current demands, why turn down the reactors? Why not keep them running and charge up some battery capacity for the day that solar+wind isn't enough?

The ideal grid would have all energy sources running constantly at their most efficient, usually 100% rated production, and use batteries to smooth out the load. The reactors wouldn't need to throttle. All that entropy would be pushed to the batteries.

It depends in part on the cost/duration required to scale reactor power up and down. It's apparently being marketed (at least per reading of this article) as a supplement for when the solar/wind grid is inadequate. That puts it in competition with cached storage (batteries etc), and gas-fired peaker plants as well. And there's a lot of uncertainty here in the market, for multibillion dollar capital investments on low-margin regulated utilities. So it'll be interesting to see what the niche is.

That said, it's still a damn sight better than the usual rounds of how super-expensive old-style light water plants are just fine, or how magic thorium breeders will save us even though no one has built one for 50 years, or other flavors of condescension at the naive treehuggers who are going to ruin everything with their technophobia.

May I ask why you aren't a fan?

A number of reasons, but for starters, consider inequality. Are we going to give Yemen a nuclear power plant? Somalia? Can Bolivia afford one?

They are expensive, require tremendous infrastructure, and mean deploying fissionable materials to countries that maybe shouldn't have them. So it's solving a First World problem, and exacerbating the divide between rich and poor.

> Are we going to give Yemen a nuclear power plant? Somalia? Can Bolivia afford one?

This is an excellent case for these lighter reactors, but perhaps more so for molten salt / Thorium reactors.

Where this reactor has smaller amounts of radioactive material and Thorium has little use in weapons.

I have a market argument against thorium reactors - basically, if they were as awesome as their proponents argue, then someone would have built one by now, for commercial purposes. But there hasn't ever been a commercial thorium reactor, and there hasn't been a serious build since the 1960s. Fifty years, and a lot of countries that aren't full of namby-pamby treehuggers to blame for it. Even India, which is sitting on like a third of the world's thorium reserves, doesn't build them.

This makes me rather suspect that thorium isn't nearly as awesome as its proponents think it is.

Wouldn't that reason cover basically every infrastructure, economic and legal improvement you could possibly think of in all areas, as long as they are reasonably hard to do for a troubled country?

Even a basic thing like a Rule of Law that we take for granted hugely increases inequality between countries that have it and those that don't.

Solution to that does not involve encouraging warlords to move into Manhattan.

If a country can't afford / can't be trusted with energy generation technology, and you care, help fix the underlaying reasons.

Another reason, as I have a moment to write... vulnerability to terrorist/military action. It's not enough to safeguard a plant against accidents. It needs to be safeguarded from malice as well - including inside jobs (a knowledgeable operator manipulating the controls, with full authorization) and brute violence, which could be crashing a fully fueled airliner into it or attacking with a bunker-busting military drone. What happens if your nuclear plant is hit with a weapon designed to destroy a modern military bunker complex? (Which could be a state actor, or an act of terrorism that somehow takes over a drone.)

Now, what happens when you blow up a windmill?

If someone blows up a reactor of this design, it will start shutting down. Meltdown shouldn't happen even if the core is badly hit, but additional cooling besides the pool may be needed. Safer than Fukushima which withstood a tsunami and operational failure with little environmental damage. (Though big economical.)

The more important risk is of theft of fissible material.

I think I mentioned in my OP that I appreciate the eye to modern safety here. But the proponents of nuclear as a (or THE) solution generally aren't talking about this design. They're either talking more of the same-old reactor designs that are decidedly not safe for these sorts of attacks, or near-vaporware like thorium that no one actually builds in the real world.

I think safety from anything short of a nuclear attack, including insider sabotage, is essential. And the only way to do that is to build a reactor that can't fail even if its containment is destroyed. I haven't seen that design yet.

edit: I'm actually less worried about the theft of fissionable material, as commercial reactor-grade materials aren't anywhere near bomb-grade, and would need a lot of refinement (a dedicated facility) to make bombs. It's mostly a problem for state-level actors like Iran that will shuffle fissionable material from their civilian reactor projects over into secret military projects. fwiw, the reason Iran even has substantial uranium is because, in the 1970s, the US was merrily building a half-dozen civilian reactors for our good friend the Shah of Iran. So when the revolution happened in 1979, those all fell into the hands of our new most hated enemies. And 40 years later, they still have all that uranium and leftover know-how and equipment to play with. Which gets back to my whole "Do we build reactors in Yemen?" question.

My concern with this is that small reactors have been tried in the past, and were too expensive to operate. The staff needed to run a reactor does not scale linearly with power output. This is why utility reactors got large. Even so, when natural gas is cheap and renewables are available those large reactors are having some trouble competing just on operating cost. Working reactors in the US are being shut down because of this.

SMR based on old school water PWR is just not the best idea. The only reason to do it, is basically because everything else is impossible to get regulated. Putting whole PWR systems in one module seams pretty crazy compared to the alternative reactors we could be building. The PWR SMR are still massively bigger other SMRs.

We built and tested better smarter designs for reactors that would be way smaller and cheaper but those are essentially impossible to license in the US and no other country has a market big enough to finance development it.

Nuclear is so energy dense the market for it is so divided that the economics of scale are just not there in the same way unless you do it stat driven as in France or you have a large unified market like the US was when nuclear was cheap and expanding fast.

Why not thorium?

Why not both? Other companies are working on thorium reactors, as well as molten salt reactors running on uranium. Terrestrial Energy in particular is pretty far along, partly due to friendly regulators in Canada.

Thorium only has advantages if you use a breeder. Uranium is actually better for most applications.

And the development of any type of reactor is already expensive, adding the additional challenge of regulatory burden to change fuels is totally pointless.

The real debate is about reactor design, not fuel type.

I also started to get interested in Thorium, but I learn that its not about Thorium but rather your reactor type.

> Thorium only has advantages if you use a breeder.

A thermal breeder, that is. In the fast spectrum the U-Pu cycle is superior.

And even so, a thermal Th breeder has a very low breeding ratio, and in the thermal spectrum poisons are worse, meaning that the reprocessing volume to produce a unit of fuel will be frickin huge. Good luck making that economical.

Yes. A thermal breeder. Correct.

There are ways to reduce the poisons depending on your reactor design.

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