Atomic Power Gets Small

There was a time when nuclear power plants were going to save the world. Barring accidents, the plants are clean and generate a lot of power. However, a few high-profile accidents and increased public awareness of some key issues have made nuclear power a hard sell, at least in the United States. The fastest growing nuclear power-related business in the US — according to sources — is companies decommissioning nuclear power plants. However, there’s a move afoot to make nuclear power a viable solution again. The company behind it says their plants will be cheaper to build, cheaper to operate, and are much safer than conventional plants. Are those claims reasonable?

Basic Idea

Nuclear fission plants are simple to understand because, at their core, they are just conventional steam generators. There is usually a clean water loop that gets heated to steam, turns a turbine, and that spins a conventional generator. If I told you the heating occurs through burning coal, natural gas, or some other fuel, this would describe a typical power generator — save hydroelectric, which uses water pressure to run the turbine.

In a typical nuclear plant, the water is heated by another steam/water loop. This primary loop uses a coolant that will become radioactive and draws heat from the nuclear core. The heat from this coolant is used to create steam in the clean water loop. There are a few reactors that use the core’s heat to directly boil the water, but that’s unusual. There are a few other less common designs. For example, one “breeder” reactor type, not only uses what amounts to solder (lead and bismuth) as a coolant but also produces more fuel than it consumes.

Why does the core get hot? Uranium breaks apart occasionally. If you have enough uranium, it is likely those particles will strike other uranium atoms causing them to break down. Heat comes from the radioactive decay process, along with the energy caused by particles colliding. In addition, the reactor will absorb some gamma radiation causing heating.

Speaking of fuel, if you’ve ever wondered why nuclear is so interesting compared to conventional power plants, you only have to look at the energy output from one pound of fuel. In theory, 1 kg of coal can produce about 8 kWh. Complete fission of 1 kg of uranium-235 can produce 24,000,000 kWh. That’s not a misprint. That’s 24 million kWH! So uranium produces about 3 million times more power than the same amount of coal. You can get an idea of what this really means by clicking the adjacent infographic from the US Department of Energy. According to it, a typical nuclear reactor could light about 100 million LED bulbs or replace over 3 million solar panels.

Economies of Scale

Typical power plants have been huge, but that’s not a necessary feature of nuclear reactors. After all, many submarines and ships use reactors, so it is clearly possible to make them where they don’t require acres of area. The reasons for big power plants are economic, not technical.

For one thing, the cost of getting a plant approved is enormous. So you might as well do several at once. You can also get some economy with control rooms, although some of that led to trouble in the past (that’s the Brown’s Ferry plant in the adjacent picture). Highly reliable control systems are also not cheap. It makes sense to have as much of the fixed costs divided by a number of operating reactors to control costs.

What Goes Wrong?

Of course, things going wrong is why people don’t like nuclear power. There are several problems, including what to do with the fuel when it is spent but still radioactive. However, the problem people fear most is the core melting down. The problem is that as radioactive decay causes more decay, it can lead to an avalanche effect. So one particle splits off two particles, which go on to split off four until, very quickly, you have millions of particles with no end in sight.

So you have to have a way to carry off the normal amount of heat, and you also have to have a way to moderate the atomic reaction. This can be done by introducing material that doesn’t permit fission to more or less absorb some of the particles flying around without producing more. Water is a common moderator. Graphite and heavy water are a few of the other choices. Typically, the reactor has a way to introduce more or less moderation to maintain a particular temperature. For example, a graphite control rod could be barely inside the core, but later lowered to absorb more neutrons. Dropping the rod all the way in — possibly because the control electricity failed — could stop the nuclear reaction altogether. In smaller reactors where rods are not practical, it is possible to use a neutron poison to accomplish a similar effect.

Without the moderation, typically, the core temperature would increase to a very high temperature. While that might seem like a good thing, it is too much of a good thing. The equipment in the reactor can only stand a certain amount of heat. In particular, all the radioactive material is usually inside a containment building, and if that melts, you will have a catastrophe on your hand. This is essentially what happened at Chernobyl, but that reactor did not have a containment structure around the reactor’s pressure vessel.

 

Fukushima had partial meltdowns and Three Mile Island (pictured) did, too. Melting through the containment structure is one bad thing that can happen but there are other concerns, too. As the fuel and its surrounding materials melt, they can form hydrogen gas which can then blow up spectacularly. Again, if the containment vessel breaches, radioactive material can be spread.

A New Scale

So what makes the NuScale reactors different? First, they are small and contain enough fuel to operate for about two years. The idea is to put more smaller reactors in place — up to twelve — if you need more power. Because they are small, they can be mostly built offsite and shipped into a prepared location. This is similar to the idea of prefabricated housing and should reduce costs.

However, it is expensive to control many smaller reactors compared to a few large reactors. NuScale says the reactors are passively cooled, so the control system isn’t as important. A typical way a meltdown might occur is when a cooling pump fails or is de-energized. The temperature will increase rapidly and — in many cases, even if the reactor is quenched by inserting all of the moderators, the heat will continue to build up if there is no way to remove it.

Passive cooling sidesteps this. According to NuScale, if you turn off all the control electronics, the passive water cooling is sufficient to keep the reactor safe. Critics, however, say that NuScale still needs to follow the rules. NuScale says that because the reactors are inherently safe, they should be able to get waivers to some of the rules that would drive high costs.

How Small?

Small is a relative term. Each module is 65 feet tall by 9 feet in diameter and weighs about 700 tons, which requires it to be shipped in three parts. The containment building is 76 feet by 15 feet. According to NuScale, each module can generate 60 MW using a light water configuration and a pack of enriched fuel rods that are about six feet long. If you put in all 12 modules in you could get — in theory — 720 MW from the plant.

As a point of reference, of the 98 currently operating reactors in the United States, the smallest is in New York and can generate 582 MW. The largest is in Arizona and with three reactors can put out nearly 4,000 MW. The largest in the world resides in Japan and produces 8,000 MW. It uses 7 reactors, each with a gross capacity between 1,100 and 1,356 MW — about 20 times that of the NuScale device. In case you are curious, the big reactor in Arizona doesn’t even make the top ten list for the world.

Coming Soon?

NuScale apparently has a deal to build a pilot plant at the Idaho National Laboratory. We’ve also heard there are similar designs in China and Russia. However, some people point out that small reactors have been around since the earliest days of nuclear power. The Army and Air Force gave up on small reactors. Once placed in Antartica had myriad problems and required removing almost 15,000 metric tons of contaminated soil. The Navy didn’t mind the cost because the reactors allowed them to have an operational advantage, but they didn’t adopt them for their economy.

Still, a lot of technology has changed. Maybe small reactors will catch on this time around. Is it safe? We don’t know. The company claims that if you do nothing it will stay safe indefinitely with no power or additional water. Then again, the Titanic was unsinkable.

In general, we like nuclear power — as long as it is safe. We know, though, a lot of people will categorically eschew anything nuclear. That’s why the medical industry dropped the word nuclear from NMR (nuclear magnetic resonance) and now call it MRI (magnetic resonance imaging) because even though nuclear in that phrase means something totally different, people were afraid.

What do you think? Should we do any sort of nuclear power? Is it possible small reactors are the answer? Or do we stick with things like wind and solar which have far less generating capacity but are — at least on the face of it — much safer. Leave your thoughts in the comments.

175 thoughts on “Atomic Power Gets Small

  1. Nitpick: That’s the cooling tower in the illustration, not the reactor containment building. That same style cooling tower is used at Natural Gas, Coal, and other plants.

    1. The illustration at the top of the article shows a cooling tower with a stylized lithium atom drawn on it, and TOXIC, EVIL wisps of RADIOACTIVE STEAM coming out of the top. Ever see one of those photographs of cooling towers with dark clouds of steam? Just a bit of photographic manipulation turns white, fluffy water vapor into dark, toxic waste.

      1. Who says it’s Lithium?
        Did you count the electrons and assume that’s the atomic weight?
        Everyone knows you only bother drawing the valence band!
        Or perhaps there is an electrical charge.

    2. I’m going to side with our artist that ordinary people associate that with nuclear power (erroneously). A short fat squat concrete cylinder wouldn’t have the same effect. Besides… it has an atom on it so it must be nuclear power! ;-)

    1. The fact is, however, that the public is not generally aware of many of these. There are a few that normal people know: 3MI, Chernobyl, Fukushima. How many ordinary people know Brown’s Ferry? Or NPP. It is like the airships. Everyone knows the Hindenberg. But very few remember the R101 or the Shenandoah. So while the Hindenberg wasn’t the first or only airship disaster, it was the one that soured the public on airships. Same thing here.

      1. Nevil shute, the author, was an (aeronautical?) Engineer by trade.
        His autobiography, ‘slide rule’ covered the story of the R100/R101.

        R100 was privately built, R101 was built by the government.

        When it was realised that R101 would be shorter than R100, it was lengthened (bigger is better, right?), And its maiden flight was brought forward so it would be first to fly.

        After R101 crashed at Beauvais, France, all British airship development was halted.

      2. The R-101 was another Challenger disaster. Lets get this teacher in space so we can do one for the gipper tonite on live TV. F the weather. The new Viceroy of India just had to make his big entrance to come and sit on the throne.

        1. I thought the idea that the Reagan Administration pushed for the launch was fairly well debunked?

          Realistically there didn’t need to be any pressure from the Gipper. The o-ring problem was well known at the time, NASA and Thiokol had been making poor risk management decisions for years. Likewise, they knew about the foam problem that brought down Columbia since the 80s. They just kept putting on their “management hats” and overriding the concerns of the engineers. There was more than enough pressure within NASA and Thiokol to succeed without admitting there was a problem. Especially Thiokol, who also made ICBMs, and who had faced a lot of criticism over their clevis joint design from the beginning.

          I think it’s Richard Cook who mostly pushes the theory about the Gipper. I read his book maybe a decade ago, and I recall it seeming very self-serving, he tries to take a lot of credit for things others did. That being said, I think Cook was absolutely right that NASA and the Rogers Commission tried to cover up the problem, highlighted in Feynman’s book, where he threatened to withdraw from the commission unless they published appendix F about NASA mismanagement.

      3. SL1 in Idaho. The first reactor to suffer a core explosion, killing three men, two were lucky and apparently died instantly, the third got to suffer for a short while before dying. Until Chernobyl it was the only reactor to explode. Hasn’t been another core explosion or other core containment loss.

        Quite the good record, two out of all the reactors around the world. There have been deadly incidents at other nuclear plants but AFAIK only at SL1 and Chernobyl have deaths been directly related to or caused by the reactor itself, and both of those were due to design issues and human error.

        Now that there’s a Chernobyl mini series, how about one on SL1, as long as it sticks to the known facts?

      4. I’ve read this book. https://www.amazon.com/Airshipwreck-Len-Deighton/dp/003046451X

        It covers all the wrecks of lighter than air vehicles, going into detail about how and why each one failed. Some were due to structural problems while others were directly caused by bad weather, improper reactions to sudden weather changes, ground crew screwups, ground equipment failures and other causes.

        IIRC one was moored just at the nose so it could weathervane around its mast but it broke loose in a storm then got blown into buildings etc and destroyed, while another was moored at both ends then got hit by storm that tore it up because it couldn’t pivot nose on to the wind.

    2. Not only that. The article fails even before that:

      “[…] the plants are clean and generate a lot of power. […]”

      Which plants? The power plants? Yes, they are mostly clean – even though there are studies indicating something else. But the process doesn’t start there and the uranium mines are not clean at all – contaminating vast areas – like around Arlit/Niger, Caetité/Brazil, etc. I would advice the documentary “Yellow cake – The dirt behind Uranium” and speaking of accidents: That list is not complete, sure, and doesn’t claim it – but why don’t lists like that for example include the Church Rock mill spill of 1979 and similar incidents?

  2. With the advances in technology and processes, yes, maybe some smaller reactors may be a good solution.

    But that company claims about it being better, cheaper, and so deserving of freedom from regulations, no. It is the same reasoning people use to buy cheap things from AliExpress, with the problems/defects/complains that follows ….

    I believe that nuclear power is safe, with the necessary precautions and correct engineering. Just do not cut corners to improve someone´s bank account.

    1. A big reason why nuclear power is prohibitively expensive is the misguided and misplaced safety demands on it.

      It’s like engineering a computer that never crashes, that can never crash, rather than simply making regular backups and dealing with the inevitable. Nuclear accidents can be “benign” in the sense that they’re manageable risks and their effects can be limited, but since it is assumed/argued that any nuclear accident is equivalent to the holocaust, too much effort is placed on engineering the “perfectly safe” reactor and not enough on dealing with whatever happens when it does break, because the reactor itself already costs too much.

      1. I agree with you in that we need to accept that accidents WILL happen all be it on low risk occasional circumstances. unfortunately it’s not as simple as ‘making backups’, working IT I can tell you that backups don’t get checked, redundant arrays get nailed by freak power surges, natural disasters, malicious/disgruntled actors, hackers, terrorists etc etc. With Nuclear Power the risk is small but measurable, power companies and insurance companies bet their limited liability businesses and personal reputations (people tend not to live more than 100 years) on taking that small measurable risk, and equating it to ZERO risk, it’s a good bet from their point of view. even if they lose the bet, and the company goes under, bosses forced to resign, they have a mountain of personal savings for their grandkids to live comfortably move out of harms way.

        However that small, miniscule risk, multiplied by power plants, multiplied again by decades and decades of complacency, increasing pressure to lower strict standards and regulation on the false reasoning of ‘there hasn’t been an accident, regulations must be too harsh!’, multiplied again, critically by the potential TOTAL COST of damage of an accident, over the FULL LIFETIME of the contamination. in lost land, construction of vast concrete containment that degrade every few decades – the risk and costs adds up, and it’s an externalized risk and expense that’s not factored into the cost of running these plants, as it’s governments and poor people end up paying the cost of any fuck up.

        I’m not saying that Nuclear should be gotten rid of, but we need to evaluate the risks with something better than guesswork, It’s not a magic solution.

        Also to be considered is the real possibility that future generations might be less capable, less scientifically advanced than we are now. And that overpopulation, global warming, and over complexification of the infrastructure we rely upon could result in a collapse in out capability of building increasingly giant lead lined concrete shells to cover up chernobyl.

        Cool talk by indy dev Johnathon Blow about this possibility:

        1. >”and equating it to ZERO risk”

          That’s exactly the red herring: the demand for ZERO risk through arguing that any and all nuclear accidents are equivalent to the worst possible case, and therefore the only standard for risk with nuclear power is exactly zero tolerance.

          But that is a double standard, because certain risks are accepted with every other form of energy – just not with nuclear power. With nuclear power the rules are different, so the designers have to build redundancies of redundancies to zero out the risk completely, rather than producing designs that minimize the inevitable harm.

          For example, with small modular reactors, if one breaks it’s not going to melt through its containment, but if it does then the contamination is much smaller in scale and more easily cleaned up, so you don’t have to evacuate an entire county when it goes pop. Yet, this is not good enough – it shall have zero risk of error to begin with, so you also must build the reactor with redundancies of redundancies of redundancies, and yet since a tiny risk still remains it is argued that the reactor can never be safe, therefore it shouldn’t be build, and in any case it’s now too expensive to build.

          It follows the theme of the argument about nuclear waste. It exists, and it’s a horrible thing, so we shouldn’t make any more. Therefore we shouldn’t build more nuclear reactors – but – when you try to bury it somewhere, nowhere is safe enough. You can’t even put it away, because if an acceptable solution to the waste problem was found, then this argument against nuclear power goes away as well – so the nuclear waste must stay as a permanent risk to support the argument why we can’t have nuclear power.

          It’s a mess of public hysteria, decades worth of propaganda, and people who have already decided what the politically correct solution to the energy problem should be and will use any cognitive distortion to shoot down any alternative.

  3. I say this a lot… the lessons of TMI, Chernobyl and Fukushima is not that nuclear power is bad, it’s that the shitty old PWR design is bad.

    If we’re going to seriously address CO2, next-gen nuclear power is going to have to be part of the conversation.

      1. Growth fuels innovation. You can’t find new power without growth, you can’t grow without power. The nonrenewable nature of fissile material on earth can be solved by leaving earth, or using that power to find better energy sources.

        If we can’t solve the issue by the time the billions of tons of uranium are mined & processed we’re deserve to go extinct.

      2. Well this fuel is not renewable but lasts a long time, was decaying anyway and once ‘used up’ can be used in a different type of reactor for yet more power. Also spent radioactive waste gets dumped in cooling ponds and stays hot, so Stirling engine on the cooling ponds perhaps?

        Sure we do need to change, but can’t do that anywhere near quick enough. Solar cell for example needs huge energy input to make.
        Then there is the trouble of energy storage – as only Tidal power of all the ‘renewables’ gives 100% predictable and reliable power. Wind may well not run at all with high or low wind, Solar at least works somewhat on dull days but does nothing in the dark.

        1. Don’t forget hydroelectric for predictable, reliable power.
          There are 6 stations near me generating 204MW between them, with less than 40 miles separating the furthest ones. Four were built between 1913 and 1928, and only one of those has gotten a significant upgrade.
          Though realistically that’s still not *that* much power, and we also have a nearby fuel oil/natural gas station that puts out 330MW (and 430MW in winter).

          One of these little stations probably looks mighty attractive for a rural-ish location.

          1. Hydroelectric power output changes tremendously from year to year thanks to differing amounts of rain/snow, and the dams silt up over time, and they put out methane due to the varying water levels that erodes the banks and traps plant matter underwater.

          2. Sure. Tell an environmentalist you want to convert mountain canyons to lakes and disrupt the path for fish to get upstream….

            There’s a reason we haven’t seen new major hydroelectric projects in recent decades, despite it being “free” untapped renewable energy.

        2. It is about 80 years until this fuel (uranium) will most probably be consumed. Yes, it will decay anyways, but mining uranium isn’t exactly ecological, and getting rid of radioactive waste is another unsolved problem.

          The efficiency of stirling engines is (and will ever be, at small temperature differences, because of thermodynamics) quite low. And if you use the “solar cells need much energy to make [and might not even produce this amount of energy during their lifetime]” argument (which is wrong), you can scrap those stirling engines altogether.

          And besides: not buying things we actually don’t need is the fastest thing to do. It does not need fancy technologies (which brought us here in the first place), money (actually it saves money), knowledge or whatever. Just stop. Buy food locally. Stop traveling vast distances by airplane to places you don’t know, as long as there are plenty of places you don’t know right around the corner. Don’t follow every fashion or consumer electronics trend. Avoid or share cars (and other expensive commodities) if possible.

          1. We don’t need comfort, entertainment, pleasure, or (you imply) progress. If your suggestions were fully carried out, we’d be living in the Dark Ages.
            There’s a reason foods bought at farmers’ markets are usually more expensive than foods bought at supermarkets: they’re more wasteful of money and labor, which means they’re more wasteful in terms of human lives.
            I will not live in poverty to fulfill your primitivist dreams.

          2. “80 years until this fuel (uranium) will most probably be consumed.” That ignores the numerous new reactor designs that don’t require enriched uranium to operate. There are molten salt breeder reactors that are much safer (can’t melt down) and actually use the current reactors’ waste products (as well as the waste from enriching uranium for current reactors). We have enough waste just sitting around in barrels to run these for a thousand years. And that doesn’t even count the possibility of using thorium which is plentiful. The biggest roadblock in using these alternative reactors?: Government. They continually drag their feet in approving new designs. Perhaps once China gets enough of these types of reactors online it’ll give someone in the US a kick in the pants and we can have nice things again.

            But based on this and other posts, I gather you’re not interested in actual technological solutions. You seem to pine for a Utopian “simpler” time where people lived closer to nature. Right? Those times were when life expectancy was lower, diseases which we’ve largely irradiated killed huge numbers of people, and a large percentage of the population had to work in food production just to feed everyone (that percentage, globally, is now less than 50% as of about a decade or so ago… for the first time in history). You can go live in a cave, but I’m not.

          3. You are 100% right a solar cell will pay back the energy cost (even the older ones that do degrade badly and have still work)- but we can’t go making lots of them without lots of energy cost, if we burn lots of oil for that we are being really really stupid, even for the human race.
            Nuclear works to fill that gap now when we need more power to make cells for a cleaner future, and provides a steady reliable backbone while we try to figure out CAES, Hydro or battery stores for the renewables. Much of the renewable energy production is wasted currently being so peaky with no rediclusly large cap to smooth the flow.

            So what that a Stirling is not going to be hugely efficient with this temp differential, like solar it should work long enough to pay itself back. And the spent fuel rods are still going to be there radiating away. At least until they end up reprocessed to go again. Nuclear waste really is a mostly solved problem, at least if anti nuke folks and timid political types would actually allow anybody to make a new reactor of any type.

            As for changing lifestyles that can help, but buy local can only be done if local can provide all you need. It is not a one size fits all change. Though if everyone thought a little about the energy cost of what they did it would help for me Air travel really is too cheap but the bigger hit environmentally is shipping everything in from Asia, and even more crazy back and forth to the cheaper labour of Asia every step of the way to finished product).

            Personally I run all me electronics till they break and I can’t fix ’em anymore, and buy new stuff only as I really need it or when it makes sense energy use wise. My NAS and some internal home network stuff used to be run off the old PC, but that idles at 100W ish.. So using a Pi that can at max draw 10W and isn’t working that hard most of the time quickly pays the energy cost back.

          4. All I intended was to point out that one has to look not just at the energy (and resource) production, but also on the consumption. I simply don’t believe that we can continue to consume as we do, and that some technological solution will reduce our CO2 emission by a factor of 10 or more (what would be necessary for a stable climate).

            To Chris Maple: I fail to see where I implied we don’t need progress. I didn’t intend to. And I also didn’t write that we don’t need comfort, pleasure or entertainment. None of my suggestions rob you of those things (except when the only activity you get comfort, pleasure and entertainment from is air travel, which, from my experience with air travel, is most unlikely).
            Locally grown food is most likely more expensive because it is not imported from a low wage country. So the price does not say much about the “human lives” spend for its production, at least if all human lives are worth the same. In contrary, avoiding buying a new phone every year is saving time for its production, and on top saves resources. Switching from a transport system where every participant needs to own a car to a combination of public transport and shared (autonomous) cars will save human lives, as we don’t need to produce so much cars. If done right one could get a more labour and resource efficient solution to the demand for mobility than we have right now.

            To TimT:
            “You seem to pine for a Utopian “simpler” time where people lived closer to nature. Right?“ I am, again, failing to see from which of my post you inferred this. I am not pleading for the de-mechanisation of agriculture. I think e.g. precision farming is a valuable addition to increase productivity. But I think it is necessary for the survival of mankind, to have an environmental sustainable economy (and I think our current economy is not sustainable). One factor is, for example, to reduce the reliance on artificial fertilizer, as nitrate based ones are energy intensive, and phosphate is a limited resource. Another is to reduce the amount of meat produced and eaten. Meat production has a major impact on global warming and on the depletion of drinkable water resources worldwide.
            I could not find much data on the percentage of the global workforce in food production, but I found it for the agriculture segment, and it is about 26% right now, and was at 31% in 2009, which is, of cource, a good development. [source: https://ourworldindata.org/employment-in-agriculture%5D. Can You please provide the source for your 50% claim?

            Best regards

          5. >” Switching from a transport system where every participant needs to own a car to a combination of public transport and shared (autonomous) cars…”

            …will not necessarily save any resources/money or lives, since the outcome depends on how the society that the transportation network serves is structured.

            If you put public transportation and robot taxis to work in the framework of how society is organized now, the result is lower efficiency because the social infrastructure is not concentrated around public transportation hubs. The private car is actually the most efficient in case of our kind of random access society where most people can go anywhere any time. The result of trying to cater to that leads to longer waits, more passenger miles than required, and more idle travel of the vehicles. Buses for example may need an average of 7 passengers on-board to beat a car, but on many routes they average about 5 because they just have to drive their routes night and day – otherwise people complain that the bus is never there when they need it and switch to driving a car.

            But, the problem with re-structuring the entire society to fit the transportation model carries its own cost. For example, property values become highly polarized between places with and without access to public transportation. Guess where the poor people end up living? Guess what happens to prices of goods when everyone has to cram into the same few places where people can actually travel? Labor mobility suffers, creating systemic unemployment and inefficiency in economy… etc. etc.

            You can introduce these solutions to the market, but don’t expect them to stick. If you force it, you’re fighting against social evolution and that’s a battle of few wise men trying to beat the wisdom of the crowd which has more diffused knowledge and processing capacity than you as the designed of the grand new utopia.

          6. >”…will not necessarily save any resources/money or lives, since the outcome depends on how the society that the transportation network serves is structured.“
            Sure. One can always assume that the system that gets implemented will be the worst possible. Not reducing the vast number of cars (and many other products) we produce will necessarily bring trouble.

            >“ If you put public transportation and robot taxis to work in the framework of how society is organized now, the result is lower efficiency because the social infrastructure is not concentrated around public transportation hubs.“
            >” The private car is actually the most efficient in case of our kind of random access society where most people can go anywhere any time.”

            How do you measure efficiency? Total time spend to satisfy a certain need? Then it’s likely that the additional time needed for travel (if any) will be more than offset by the saved time producing less cars, or the reduced time needed for earning money to pay for cars. Replacing ~120 cars with a bus during rush hour will reduce traffic jams. So the travel time could actually be reduced, compared to everybody going by car.
            Besides, usage of cars is surely not a pure random access thing. If it would, traffic jams were not a regular phenomenon. The pure existence of UberPool indicates, that people go the same direction at the same time a lot.

            You argue that in our current society, which is optimized for the car, the car is the most efficient means of transportation. Would be a shame if it wasn’t, wouldn’t you say?

            I intendedly wrote: public transport and shared autonomous cars, because I am aware that busses/trams don’t do well for the last mile. Autonomous cars could fill that gap. Or bicycles. And why on earth would you let drive buses at night, when there is almost nobody traveling at all? As I wrote: you can allways come up with not so clever solution, and say: Hey, that is much worse compared to now, so let’s not change a thing!

            You mention that a change of property values (which would be introduced by change in the transport system) is a cost. Well, if it is a cost, we already have it, but for different reasons. The poor tended to live in suburbs (in the US, as far as I know), but for some reason rich people moved out of the city centres, and the poor moved in. Maybe, in a few decades, this changes again. To me it looks like a cycle (also in here in germany). The poor always live where it is cheap. Switching to a better public transport could at least level out the differences a bit, as the cost for transport is paid for by the society.


            My 2 cents to the main topic: as a lot of the discussion revolves around risk: to me it seems that private companies earn money (a lot) with nuclear power generation, and the public takes all the risk. That is highly unjust. If the public has to take the risk (because no insurance will ever cover it), it should also take the profits.

          7. “It is about 80 years until this fuel (uranium) will most probably be consumed”
            ROTLF are you kidding, right?
            “getting rid of radioactive waste is another unsolved problem.”
            nonsense. is a very simple engineering problem, if engineers and not politicians were in charge of solving it.

        3. But nuclear fuel is largely renewable. 98% of the fuel from ‘used’ fuel pellets is still good, and can be separated and re-used.

          Nuclear power is largely renewable. Its not a fossil fuel, and if we ever hope to leave this planet, its the only possible fuel that will allow us to leave beyond Mars.

      3. Using breeder reactors and both uranium and thorium, there would be enough fissile material for millenia.
        More than enough time to transition to a fully sustainable economy.

        One thing they have right–a modular, mass produced design is a must to bring the cost down. The modules must also have full passive safety.

        My questions are: Is nuclear a necessary part of that transition? If not necessary, is it economically viable? Is it politically viable?
        I have increasing confidence that the answers are all “no”.
        Photovoltaic, solar thermal, and wind can provide the energy needed to sustain the economy, at less cost and with less risk.

        1. All well and good having lots of energy yesterday when the sun was shining, a gentle breeze blew, the hyroelectric’s still had water. But it does you no good tonight in heavy winds, gentle moonlight and still with no water left in the dam.

          Fully renewable (which is really just another way to say powered by that big ball of hot gas at the center of the solar system) needs energy storage.

          Batteries are not there yet, and may never be there as even if we find a battery chemistry that is stable, small enough all while delivering the needed level of power odds are great we wont’ have enough of whatever minerals it is made of.
          Capacitors might work, but don’t have the energy density of most batteries. At least the right types of cap last a very long time though which is a huge compared to remanufacturing of batteries.
          CAES/Hydro pumping for storage might work but efficiency and land areas that would be covered can be troublesome.
          Hydrogen either burned or as a fuel cell (so burned in an odd way) again has issues of efficiency, then there is also just how much water would we take out of circulation and would that be enough to cause ecological troubles?

          I’d say with just how much water our planet has hydrogen is probably top of the list for now. Though CAES being such a simple and cheap tech could become prominent in many areas. But either way none of this is built or studied yet where Nukes can give us clean power to backbone the grid and time to figure it all out.
          After all economically its definitely viable – nothing gets made with no power
          politically at worst it will become viable once the aforementioned nothing gets made becomes lots of unemployed and hungry folks

          The only way I can see it becoming possible with current thinking to not have many, many more nukes is if we can all enjoy the brownouts so the important to everyone stuff like making and distributing food and water can get done in the lull energy output spots. As no amount of wishful thinking can make the sun shine (near you) at night or existing wind turbines work in really low or really high winds. I expect most of the folk here will be setting up their own backup power for these occasions as we know somebody or can do it ourselves. But everyone else isn’t likely to cope with it, so being politically a bad idea its not likely to happen.

          1. Where I live, winter means well-below-freezing temperatures and up to 15 hours of darkness.
            Plenty of people live north of me, so storage is definitely an issue for wind and solar.
            I’m just more optimistic about solving that problem than I am about solving the problems of nuclear power.

          2. You forgot thermal storage, a simple technology that works well for the majority of residential energy use – HVAC and hot water. The remainder takes surprisingly little energy in most homes.

            Also, we should be pushing for higher efficiency starting with what gives the most return for the investment in effort. For example, there’s no excuse for a new car to get less than 30 MPG highway – in fact, it doesn’t even take any exotic technology.

      4. Yes many don’t think about, that nuclear fuel is finite resource. The same old mindset is in play. There there’s so much of this or this or that, Humankind can’t make an impact.

    1. Never underestimate the stupidity of people, either in commenting on blog posts about nucleair power, nor in managing to trigger an accident with disastrous consequences nor in situations where a nucleair reactor end up being in a war zone like beirut in the last century or syria now. If the old egyptians had nucleair power, we would not be visiting the pyramids for the next few millenia because of wars in the delcining years of their empire and the resulting loss of knowledge about nucleair power. Its not the reactors who will be the problem. It’s us humans…

    2. PWR (Pressurized Water Reactor) design isn’t actually bad. Of the incidents that you listed, only TMI was a PWR design. TMI’s problem wasn’t a design issue, it was a training, maintenance, and operations problem. Chernobyl was a RBMK ( Reaktor Bolshoy Moshchnosti Kanalnyy) breeder reactor design, inherently unsafer because it had a very positive void coefficient of reactivity and it was really designed for plutonium generation (electricity was just a side benefit), and Fukushima was all BWR (Boiling Water Reactor) that has issues of its own.

      I agree that next gen nuclear power definitely needs to be in the conversation. But that’s not going to happen when people aren’t properly educated about it. Ask almost anyone on the street and they will say that they are against nuclear power because it is too likely that there will be an atomic explosion from the plant. The media keeps feeding the narrative that these were atomic explosions in these incidents, but that is far from the truth. If any of those incidents actually had an atomic explosion, the plants (and anything near the plant) wouldn’t even exist now.

  4. “Barring accidents, the plants are clean and generate a lot of power.”

    That’s bullshit. They generate a lot of ultra dangerous waste. Much of Fukushima’s fallout is due to the waste that was stored at the site. It’s like saying “Barring the exhaust gases, Diesel engines are clean and generate a lot of power.” The fairy tale of clean nuclear energy is just that. Laymen just do not understand stochastics. And capitalism. If they did, they wouldn’t want a nuclear facility on the same hemisphere.

    1. no. fukushima’s spent fuel pools were barely damaged and did not contribute significantly to the release. the problematic elements (cesium, etc) in the fallout are mostly just a problem in an operating reactor. they are produced while it is operating and decay relatively quickly. it does take the waste a few years (on the order of a decade) to cool off enough to not require activate maintenance (monitoring and cooling), but once it does it’s not really very dangerous. the low-enriched uranium that most of these things are fueled by is just not very exciting. it takes it a million years to decay *because it isn’t decaying very quickly*. the things that are scary are the ones that decay quickly (releasing a lot of energy today), but then they don’t last as long.

        1. Truly clean? I wouldn’t say truly IIRC the rare metal in it isn’t that easy to get, it’s energy expensive to produce and the people getting the metal aren’t really protected (very nasty).
          Not that nuclear is better, I don’t know, but even if the final product is clean, doesn’t mean that how it is made is clean. And nature only care about the overall impact!

          1. > then you are going to have to give up an awful lot of modern tech to avoid being a hypocrite.

            The same argument does apply to an awful lot of modern tech, and this issue has to be solved as well.

            For example, it would be perfectly possible to smelt iron without using carbon to reduce the ores to metal, but the energy has to be very cheap (competition: 1-2 c/kWh with Russian coal), available in a concentrated fashion, and steady in output because your smelter can’t run in an intermittent fashion (it may, but the cost goes up).

            What source of energy could do that?

          2. I think you want me to say Nuclear Fission but based on the latest rector being built in the UK the agreed strike price is 9.25pence/kWh (~12c/kWh) and the plant is going to be one of the most expensive buildings ever built at ~£20bn, so does not currently fit your spec for “very cheap”. I’m afraid that as far as I know we don’t have any technology yet that can satisfy your question.

      1. 96% of reactor waste can already be recycled back to fuel, and the remaining waste has high activity (short half-life) so it breaks down in a couple thousand years rather than hundreds of thousands of years.

        You could also force the fission of nuclear fuel in a sub-critical reactor that shoots a beam of neutrons into a lump of sub-critical fuel, burning it up completely. With a core of fresh fuel that acts as a neutron multiplier, and a cladding of spent fuel, the spent fuel can in theory be broken down all the way to inert lead. The difficulty is coming up with a particle accelerator that consumes less energy than the reactor produces. If such accelerators can be made, the reactor would be inherently safe because the neutron beam can simply be turned off to stop the reactor.

        1. I fact, the big problem with nuclear waste is that there’s both low/medium and high level waste mixed in the same spent fuel rods. The high level waste keeps producing neutrons, which breeds more high level waste out of the rest of the fuel and keeps it hot for a long time.

          Simply separating the two, even if the waste wasn’t being recycled, would make dealing with the waste a whole lot easier. Unfortunately, it is politically decided that reprocessing (at least in the US) is not allowed.

      1. Indeed, and maybe not so much with the LFTR design but with designs that use sodium, once it dissolves through it’s containment you have a load of salt that is going to ignite as soon as it hits the air, and even worse if you’ve left water lying about.

    1. LFTR’s are a possibility, most of the issues are engineering. They are quit solvable if we were to put our minds to it instead of say blowing money on Musk’s virtue signalling toys.

      AFAIK even the Chinese and Indians are looking into this technology.

      The problem is the anti-nuclear fanatics in the West paint them worse than Chernobyl

    1. Yup, you got it. That’s exactly how quality science is done. Take what some politician says will happen and if it doesn’t happen exactly as predicted then that is proof positive that the opposite is true. No actual data is required.

      You can go enjoy your [small]pox party now.

    1. I heard from an engineer that visited Antarctica that it had a high background radiation before the reactors showed up, and a lot of what was thought of as “leakage” was already present before it was assembled.

  5. Those last two paragraphs were really unnecessary. Please keep that kind of stuff off of hackaday, it’s the last place on the internet that we can avoid they kind of violent hyperbole.

    1. I disagree. We are being overrun with all sorts of stupid in the form of anti-nuclear power demonstrators, anti-vaxers, maga hats and more. It is making our world a worse place and threatening to do permanent damage. We should call it out wherever we see it not encourage it to get worse with tolerance.

  6. Nuclear power is nice. Solutions can be found for problems like the waste.

    However, apparently about once every 20-30 years something that nobody expected happens and we get a big environmental problem.

    You can of course say, well, that won’t happen again! Sure! But it is the unexpected things that get us. Every time.

    The risk that we’re taking: making a significant part of hte world uninhabitable and changing the WHOLE world due to ONE accident is simply too big. (that would take an accident slightly bigger than Chernobyl, but who says that won’t happen?)

    With airplanes you don’t want them falling out of the sky. So we learn from past mistakes but again and again screwups lead to a batch of dead people. But that is highly localized. Very traumatizing for the families involved, but life goes on. With nuclear power things can be very different. Tens of thousands dead and many many more in the aftermath.

    We have too little experience with the reactors that we already have to estimate the chances of a big mishap. And then people keep inventing new ones that are supposedly even safer. But we just don’t know their failure mode yet. Things WILL go wrong in unexpected ways.

    1. Arguably more people die from the small but constant pollution of regular power plants than die from the sudden mass pollution in a nuclear disaster.

      And iteration is how everything improves, so “don’t iterate” is a nonstarter.

    2. i agree with you that it is wrong the way some advocates pretend accidents won’t happen. but this word “uninhabitable” is also ridiculous. most of the exclusion zones around past nuclear catastrophes are absolutely habitable. the radiation level is somewhat higher than background. maybe if it was inhabited there would be startlingly high levels of cancer in places. but especially around chernobyl, there are specific localized places with big chunks of core where it is still very hot surrounded by vast acres of low contamination. nuclear power disasters are bad. increased risk of cancer is a tremendous price to pay. but the idea that they would cause the extinction of any communities living within a hundred miles of them is hogwash. my city is polluted with all number of chemicals known to cause cancer and birth defects, and indeed I personally know someone who experienced birth defects. it’s tragic but he’s still alive and no one is saying his home town is or was inhabitable.

      1. And I would even add that around Chernobyl, because there is no humans to disturb, nature took back, trees grew and animals start (not even start, are) wandering around. I believe I saw it on the Netflix documentary “Planet” last episode!

    3. >”and we get a big environmental problem.”

      Most of the “big environmental problem” is about governments and people over-reacting and applying heavy handed measures that do more harm than the accident itself.

      For example, the Japanese government evacuating and emptying areas according to an outdated and discredited, completely arbitrary radiation safety standard – purely out of public hysteria.

  7. We all know how many gigs or terabytes we have on hand, but when it comes to large amounts of power or power/hours we go crazy with a small unit and lots of 00000000000’s. One of the biggest gripes of the Metric system is people’s wasteland of zeros instead of using correct suffix. Then there is that power unit oft quoted as “n number of houses”. Is that with or without natural gas included?

  8. Sigh. No one follows Scott Adams (Dilbert) or Bill Gates?
    There is FOURTH GENERATION NUCLEAR POWER. It burns existing nuclear waste. It is safe in that it can’t meltdown in a failure (3rd Generation is also much safer, the “accidents” mentioned in the post are from 2nd gen or earlier or something stupid like requiring diesels to pump water upward instead of letting it flow downward in Fukushima).

    One example is the LFTR – Liquid Flouride Thorium Reactor, or “lifter”. There were many designs even back in the 1950’s but we needed nuclear material for the cold war.

    Meanwhile, the desert isn’t empty but most “green energy” advocates are willing to kill ever desert tortoise, lizard, bird, cactus, and insect by putting solar farms up, or kill to extinction birds, especially raptors like the Bald Eagle and Golden Eagle with the windmill bird choppers.

    Oh, and we could continue expanding Hydroelectric but in this case the greens get all upset over some not-endangerd fish. Not the Hetch Hetchy in Yosemite National Park (it supplies Silicon Valley and some suggested removing the dam to restore the very beautiful valley), but everywhere else.

    1. What is this rambling nonsense? Hetch Hetchy Reservoir has been around for almost 100 years. Environmentalists should be advocating for its removal instead of finding new solutions? You offer no insight as to the environmental impact of a solar farm or wind plants. You don’t think environmentalists consider tradeoffs between energy sources and their impact on the ecosystem?

    2. I live in the high desert of So- Cal near the Wind farms of Tehachapi. There are also a smattering solar power sites. Here’s the thing about putting solar panels in the Desert. The builders remove the preciuous and thin layer of top soil to make sure weeds don’t grow. Problem is it makes that piece of the Desert – Dead as a slab of concrete. Even if you remove those solar panels nothing will grow for many centuries or a millenia because it takes a incredible amount of time for nature to restorue.

      The city people don’t care because they don’t consider the desert a ecosystem at all.

      BTW that wind farm is a joke. Half of them are offline at any given time and when there is no wind, all of them are still. And yes those wind farms are bird killers it’s a well known fact.

  9. There has never been a solar or wind or wave renewables disaster. However, there is a cost to the construction of wind and wave with regards to steel and concrete and it is less favourable compared with the lifetime of a nuclear power station (per KWh). Without disasters, Nuclear is greener (except solar). It is also not possible to use renewable power generation as part nuclear weapons material processing.

    1. Solar thermal fries birds that are attracted to the bright light. Windmills swat the dumber birds out of the air when they try to land on the moving blades.

    2. Sure there has. Look up Solyndra. When that place failed it took billions of our tax dollars with it. I don’t know what you consider a disaster but, that sure fits my definition.

        1. You did not consider the long term tax ramifications, which we are still footing the bill for. So, even using your low 1/2 billion, over the next 10 years that will easily total several billion dollars as a loss, hence my term “billions”. A disaster does not have include people being killed in order for it to be a disaster. As a taxpayer, seeing my hard earned money going down the toilet for some stupid scheme to payoff political contributors is a disaster. Solar can not compete in energy production and probably never will be able to.

          1. I’m an engineer, not an accountant. You’d need to give me a link on the “long term tax ramifications”. Or you could just admit that you exaggerated.

            I never claimed a disaster had to involve loss of life.

            If you think your tax dollars going to some stupid scheme to payoff political contributors is a disaster, I’ve got some bad news for you about the F-35 program.

            You speciously equated the “disaster” of squandering tax dollars with real disasters like Chernobyl and Fukushima in order to claim that renewables have also caused disasters.

            Of the utility-scale electric generating capacity added in the US in 2018, nearly 5% was solar (https://www.eia.gov/todayinenergy/detail.php?id=38632). Seems competitive to me.

    3. >There has never been a solar or wind or wave renewables disaster.

      On the supply side there has.

      For example, Mitsubishi quietly buried a mountain of nuclear waste left over from rare earths mining, because the local populations were getting leukemia from the contaminated earth. The rare earths they mine go into things like the massive permanent magnets of modern direct-drive wind turbine generators, and the side effect is nuclear waste because REEs occur in deposits along with uranium and thorium.

      https://www.nytimes.com/2011/03/09/business/energy-environment/09rareside.html

      For solar power, all you have to do is search for silicon tetrachloride dumping in China – the cheap price of your solar panels comes from the fact that the manufacturers don’t give a lick about dumping it in the environment, as well as using coal for the energy to refine the materials and run the factories. 80% of the market for solar panels is from China because they’re the cheapest, because they don’t give a hoot about polluting.

  10. Solar is only green in the generation of power. The manufacturing of panels and the waste it produces is pretty bad, then you need storage, more batteries. More waste.

  11. How about some data. Forbes Magazine article. https://www.forbes.com/sites/jamesconca/2012/06/10/energys-deathprint-a-price-always-paid/#52556fff709b

    Energy Source Mortality Rate (deaths/trillionkWhr)

    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)

      1. Oil and gas produced in the USA puts downward pressure on global prices, reducing the economic and military power of troublemakers such as Russia and Iran.

          1. First, a shift to electric vehicles would increase the demand for oil (for generators to produce the extra electricity needed for your EVs). Second, EVs suck for range and “refueling” time. Third, EVs are expensive as is the cost to replace the battery after seven, or so, years. I won’t own one because of numbers two and three. I have better things to do with my money.

          2. ([MOW]’s comment is nested too deep, so I’ll reply to my own.)

            Only 0.6% of US electrical generation comes from petroleum (https://www.eia.gov/tools/faqs/faq.php?id=427&t=3); the additional electrical generation needed to charge the EVs would not significantly increase the demand for oil.

            Lots of vehicle uses fall within EV range and recharge time limitations. US transportation sector consumption of petroleum is 13% of the world total, not every vehicle would need to be replaced to make a dent in world demand.

            “Currently, most manufacturers are offering 8-year/100,000-mile warranties for their batteries.” (https://www.ucsusa.org/clean-vehicles/electric-vehicles/electric-cars-battery-life-materials-cost)
            Even then, replacement is not required, although range will decrease. The cost of batteries is projected to continue to decline.

            By “radical shift” I didn’t mean mandating EVs for everyone; more like continuing to spend public funds on battery research and subsidizing EV purchases.

        1. Oil and gas produced anywhere puts ‘downward pressure’ on global prices. That’s simple supply and demand. It would be much better to do as JDX said and reduce the demand.

          1. The problem is there is no viable replacement for oil and NG. None. Solar, wind are worthless for baseline energy demands needed in a 1st world country. Germany found that out, they ended up abandoning nuclear in favor of solar and having to import more NG and oil from Russia.

            You can work without baseline energy, but blackouts will be a daily occurance. Your typical high rise will have to be abandoned during that time because no HVAC and water.

            Also you cannot store solor or wind energy. At night you don;t have either so fossile fuels have to make up for the loss or you get used to sitting in the dark.

            So JDX is talking out his pants like most greenies do.

            Reducing demand? The only real way is to reduce the population of 1st world countries or get rid of industry and private transportation. Also mandate strict energy usage quotas on people.

            Basically you and JDX want to impoverish the West and make the lives of it’s people miserable as hell.

      2. Just in case it’s not clear: the estimates from coal and oil are dominated by lung problems. This is the pollution effect. The study didn’t include deaths from wars, which is probably fair.

        But yeah. The nuclear vs coal/gas tradeoff really seems to be an accute vs chronic one. Nuclear does very little damage to earth/humans, but when it does, it’s fairly spectacular. Coal and gas do continuous, larger, but more diffuse damage. Pick yer poison. It’s all poison. :)

  12. For anyone that is really interested in safety and wants to read an easy to understand book as to why we definitely SHOULD be using nuclear power, I highly recommend a book , written back in 2007, called “Power to Save the World”. Info at https://en.wikipedia.org/wiki/Power_to_Save_the_World . Of course, that was written before Fukushima, but it still is very sound and the principles still apply. I know that there is a resurgence of talk about Chernobyl because of the new HBO series, so I won’t get into that, but Fukushima was the result of a worst case scenario compounded with ineffective decisions being made at the top level with people who didn’t understand the problem. It was like they didn’t really learn anything from the lessons of Chernobyl, even though Fukushima was more of a inherently safe design, and did actually have a proper containment vessel.

    Al, this is a well written and researched article. I know that Los Alamos actually worked on this about 10 years ago, so I am glad to see that it might actually come to life at some point.

    1. Yes, they do, thanks to ADM Hyman Rickover. I used to be an operator for one of them. They are substantially smaller than a commercial plant and are inherently safe, but they do require highly trained operators. They do have more energy output than the NuScale one above.

  13. Cooling towers …

    Some years ago there was a nuke plant named Trojan. It was on the Columbia west of Portland.

    I was flying over in a Citabria one afternoon and thought the cooling tower looked like a giant trashcan — it was shut in.

    Well, I was munching on an apple at the time getting down to the core, and chuckled to myself thinking maybe I could turn it into apple corium.

    Descended to legal minimums and made a pass, tossed the apple core out the window and made a basket.

    And I chuckle every time I see a cooling tower. Even a tiny one.

  14. Hmm. I think ours might be the biggest…

    Bruce Nuclear Generating Station is a nuclear power station located on the eastern shore of Lake Huron in Ontario. It occupies 932 ha (2300 acres) of land.[1] The facility derives its name from Bruce County in which it is located, in the former Bruce Township. It is the world’s largest fully operational nuclear generating station by total reactor count, the number of currently operational reactors, and total output. The station is the largest employer in Bruce County, with over 4000 workers. [2]

  15. “Typically, the reactor has a way to introduce more or less moderation to maintain a particular temperature. For example, a graphite control rod could be barely inside the core, but later lowered to absorb more neutrons. Dropping the rod all the way in — possibly because the control electricity failed — could stop the nuclear reaction altogether. In smaller reactors where rods are not practical, it is possible to use a neutron poison to accomplish a similar effect.

    Without the moderation, typically, the core temperature would increase to a very high temperature. ”

    It’s a pity the author apparently doesn’t understand what “moderation” means in the context of nuclear fission. There appears to be a confusion between moderation, absorption and poisoning.

    In a thermal neutron reactor, moderation slows down the neutrons emitted from a fission event, thus INCREASING the chance that the neutrons will trigger another fission. Water and graphite are common moderators.

    Reactor poisons are used to control the reaction – control rods are usually made of a reactor poison such as boron or cadmium [NOT graphite]. Fully lowered control rods WILL stop the nuclear reaction altogether [otherwise you have BIG problems]. Control rods are raised to modulate the power output of the reactor while maintaining it in a state of delayed criticality.

    The last sentence quoted is completely wrong – without moderation a reactor cannot sustain a chain reaction.

    1. Well, all that wasn’t actually the point of the article, but once I reread it, yes I blended a few things there.

      I was deliberately trying to avoid the topic of poison, although I felt I had to mention it in passing. So just to clarify, the moderation effect reduces the fuel enrichment needed and the control actually absorbs or otherwise disrupts the process.

      So while I take your point, and you are right, I will counter two of your statements. Like I said, some control rods contain graphite, although I agree what I wound up with didn’t make that clear at all. Most notably, Chernobyl) had graphite elements (displacers) at the ends of the control rods — apparently now considered a poor design if you read the INSAG report. Second, your statement about without moderation is not totally correct as I understand it. Fast reactors use no moderation at all. Again, I didn’t really want to get into that.

      After all, making generalizations about reactors is about like making generalizations about CPUs. They all do the same job in mostly the same way, but there are a lot of subtle differences. Thanks for keeping me honest ;)

  16. Once these become popular worldwide (as would be necessary for this to have any real effect), I’m looking forward to getting random broken and radioactive ones added to scrap metal and coming to a walmart near you in the cutlery section.

    1. They already screen for radioactive metals at the scrap yards.

      They’re sensitive enough to find a smoke detector among the rubble, so I doubt an ex nuclear reactor just accidentally slips through.

      In fact, the radiation safety standards for recycling are double standards: you’re allowed to pass a certain amount of radioactive material if it comes from any other source except the nuclear industry. In the case of materials recovered from the nuclear industry, you have to treat it as nuclear waste stuff that radiates way LESS than the average background radiation.

      This is why Germany is storing hundreds of thousands of barrels of water in old salt mines, because they come from the cooling loops of nuclear reactors. The anti-nuclear folks are crying about how the barrels are now leaking, and how these deposits of old jumpsuits and other “low level” waste are a great hazard to everyone. Meanwhile, if similar water that contains small amounts of nuclear isotopes were coming from, let’s say a hot wells spring, you could bottle it and sell it at a health spa. You can genuinely have a block of granite for your kitchen counter that radiates more than the stuff that has to be put away as low level nuclear waste – the standards for materials from the nuclear industry are 30 times stricter than for any other industry – and yet this would be perfectly safe for you.

      The only difference is that a law has been made to prevent anyone making any sensible decisions regarding nuclear power – quite deliberately. These “safety” regulations are made in order to raise the cost of operation and decommissioning to the point that nuclear power becomes economically infeasible. Then it is argued that nuclear power is infeasible because it’s too expensive.

    1. Depends on how much public/government hysteria you add.

      For example, do you permanently empty half the county because of a radioactive xenon fart (while ignoring all the radon that keeps coming off the ground).

  17. Believe it or not, but there are actual reasons why LFTRs are not commercialized. Those salts are corrosive as hell, and will eat basically any conventional containment vessel you use. You’ve got to use some crazy ceramics instead. It’s an active research area but it’s expensive and uncertain – exactly what you _don’t_ want in a new reactor design.

  18. Well, as said above, humans want to go up there, space, planets, stars, but they need to be much more resistant to radiations like solar wind and things like that, therefore, we must mutate, and we have started the process 80 years ago, blowing bombs all around the planet first (Los Alamos, then Japan, and the Bikini and Mururoa for the Pacific ocean, and Sahara, and some remote Russian and Chinese deserts) and then drowned wastes and submarines around all seas, and a few power plants accidents here and there, we’ve all been irradiated, most of our parents too, my thirty one year old son is the third generation of that evolution of mankind.
    So yes, more nuclear power, everywhere, is the solution.
    Of course there are side troubles like the people that didn’t evolve fast enough get cancers and quite awful sickness before dying, but anyway, aren’t there too many of us on the planet ?

    ;oP

    1. People aren’t quite so sensitive to radiation as some would like to tell you.

      The current safety standards are based on a model called Linear No Threshold (LNT) which takes data from people who have received high doses of radiation and extrapolates downwards to say that if you’re 20% likely to get cancer from this dose, then you’re 2% likely to get cancer from a dose that is 1/10th as much.

      Which is like saying that a fly landing on your nose has a small but existing risk of fracturing it, because a flying brick landing on your nose is quite likely to.

      1. Cancer risk is obviously different from the risk of flying bricks. The nature of cancer is that if an otherwise functional cell with damaged DNA replicates, it may become cancerous.

        Gamma radiation can pierce a cell wall without harming any of the molecules in the cell. It can also randomly harm just one of the molecules, without harming the others. If the radiation just happens to cut a piece of DNA in exactly the wrong place, AND it doesn’t damage the cell’s ability to replicate, AND the cell does replicate using that damaged DNA, AND it manages to replicate again, AND the body doesn’t destroy it in time, it becomes cancer.

        This particular sequence of events can happen perhaps once in a billion or trillion times, so it’s extremely unlikely. But because you have billions of cells, and are constantly exposed to background radiation, it does happen regularly.

        But the more cells that are exposed to radiation and that are replicating, the higher the odds become. The idea behind radiation limits is to hold the odds to an acceptable level. It’s simply a matter of applying statistics to actuarial tables.

        1. >Cancer risk is obviously different from the risk of flying bricks.

          Cells have evolved in an environment that already has background radiation, and isotopes such as Potassium-40 which accumulate in the body. The cells have repair mechanisms against DNA damage, and self-destruction mechanisms when the DNA is damaged beyond repair. Then you have T-cells which destroy cancerous and other misbehaving cells if the self-destruct mechanisms fail. The body has to deal with these mutations in the trillions already because DNA replication errors happen anyways, cells turn to cancer spontaneously, but if the cancer isn’t particularly aggressive your own body usually deals with it. Eventually though, everyone who lives long enough will develop terminal cancer.

          It becomes a problem when these repair mechanism get overwhelmed, which was the point of the fly-and-brick comparison. People have a tolerance for radiation, so your risk of cancer does not actually increase significantly until much higher doses.

          But even if the LNT estimate was true, you could still calculate the expected number of deaths per TWh of energy produced (which they have), and the calculation including all the nuclear accidents to day comes out less than other forms of energy. For example, wind power kills more people than nuclear power because the technicians keep falling off the turbine towers, and the amount of pollution produced in their making is killing people to diseases (which include cancer).

          1. Then there’s also other discredited theories, such as the “hot particle” theory, which posits that in a nuclear accident or release of radioisotopes, all you need is a single “hot particle” lodged in your body where it will remain in a single spot and irradiate the surrounding cells, greatly increasing your odds of getting cancer to the point of making it a certainty.

            Trouble is, the “hot particles” do not stay in place. They diffuse and move around, and eventually get eliminated from the body. People have inhaled things like plutonium dust, and it does increase their odds of lung cancer, but the effect is millions of times weaker than the theory would predict.

            So great propaganda was made early in the day, with people like Ralph Nader claiming that exploding a pound of plutonium as a dirty bomb in the atmosphere would be enough to kill essentially everyone on earth. With more information and later calculations, it was shown that about 2 million people could eventually die, if all the dust was inhaled. In practice, if you did explode such a dirty bomb, almost nobody would die because the dust would end up anywhere but in people’s lungs.

  19. The main issue seems to be more about dealing with the large amount of waste produced. Some designs are supposed to reduce waste production but they’ll only reduce some kind of waste production and they’re still only designs, i.e. they don’t exist in practice (some have even been tried and couldn’t be gotten to work reliably).

    What do you do with thousands if not millions of waste that will radiate for several millenias at least? Current “solutions” are to dig holes deep in the ground, seal everything and hope nothing will happen of 10,000 years. Loooking at the setups that already exist, we know that containers rust and leak in less than a couple dozen years (and fires can eveb also happen). That’s not even the main issue though: there are no plans made to be able to open the places and remove the waste if that were to be needed. Obviously it turns out that nothing is perfect and actions are sometimes needed.

    1. The US produces about 2,000 metric tons of nuclear waste a year, most of which could be recycled (96%) if it was legal.

      The amount of waste is surprisingly little. If we assume the waste has the density of water, it would fit in a single 50x10x4 meter swimming pool. A single deep borehole about 50 cm wide drilled to 5 km (3 mi) could hold all of it at the bottom 2 miles.

      800 such boreholes would contain ALL the nuclear waste stockpile accumulated today, including ALL the waste produced by the Manhattan project (3/4 of all nuclear waste).

    1. :)

      I was honestly taken by surprise here, but maybe I should have known better.

      I live in Germany, and a generation here grew up avoiding vegetables grown in the Chernobyl fallout path, and as such they’re reflexively (IMO) anti-nuke, despite having some of the best engineering and most stable tectonics in the entire world. And despite being located next-door to France which makes an outrageous percentage of their electricity from nuclear plants with very few incidents. France is a model for how it could be done, IMO, and I have no doubt that it could be done as safely here.

      I’m still surprised by how emotional this topic gets. I would have thought it was science and that we could talk with numbers.

      1. Hello Elliot,

        please keep in mind, that many nuclear power plants are at the German border, and those are not the safest ones!
        https://www.deutschlandfunk.de/pannenreaktoren-am-netz-deutschlands-sorge-um-belgiens.724.de.html?dram:article_id=429895

        The Belgian ones are known to be above the planned usage, and show signs of fatigue on the pressure vessel.

        We are certainly happy getting electricity from them, but the decision to step out of the nuclear power is a problem! As we need the power, and politically decided to stop the usage of it, we can’t build new ones.
        This creates the opposite effect, of far higher risk as the old plants everywhere are used above the designed lifetime.

        But this discussion is some kind of taboo, as the fear has risen, and trust was lost.

      2. The majority of French nuclear plants have been built more than 20 years ago, and now exceeding 30 years in average. The owner, EDF, plans to extend to 50 or 60 years their usage.
        The more recent attempt to build a new nuclear plant is Flamanville 3, which suffers long delays because of metal welding issue or other concrete weaknesses. It is not even talking about nuclear related stuff!

        All in all, it is an open Pandora box for the decades to come…

        So, I think France is not really a model regarding this topic. Is there only a model? :-/

        ps: I’m French living in Germany

  20. While nuclear products can generate a lot of energy per mass, you can’t run a plane off a nuclear reactor. Even if you stripped all the shielding and got the weight down to the minimum, the power to weight ratio is still too low. Is there a concise engineering or physics term to describe this? E.g. For transportation, nuclear energy is restricted to settings such as nautical or outer space where its ___ does not present an impediment.

    1. “you can’t run a plane off a nuclear reactor. Even if you stripped all the shielding and got the weight down to the minimum, the power to weight ratio is still too low.”

      The same can be said for solar or wind.. well, there are solar planes, but very stripped down, and you could argue that a sailplane is wind powered, but there is that problem of calm days, with little sun for thermal lift…
      B^)

  21. Molten Salt reactors. Gen 3 and Gen 4 designs. We’ve come a long way, but we have people in power who make money off of the status quo, so we don’t innovate.

    Solar? Gallium Arsenide….let’s kick some arsenic into the environment.
    Wind? Calculate the carbon needed to build and maintain the wind turbines and then get back to me about how that method of power generation is “green”.

    Any solution to future power must involve nuclear.

    1. New reactor designs mostly exist only on paper or as problem-plagued pilot plants.
      Likely, the dream of clean, safe, cheap nuclear power will remain a dream.
      Investment is moving away from nuclear and toward wind and solar. The risks are lower and the return is better.

      Escape of toxins to the environment from solar panels is a concern. Data for GaAs is sparse because it was too expensive for terrestrial applications until recent advances in thin film fabrication. However, studies on other types of cells suggest the risk is manageable (https://www.energy.ca.gov/reports/500-04-053.PDF).

      The carbon footprints of wind and nuclear are roughly the same as far as grams of CO2 emitted per kWh produced.

    1. It’s amazing to see, whenever nuclear technology is under discussion, how many commenters appear to attack it. Are they brainwashed by some media?
      /Joke

      People who disagree with you are not automatically corrupt. How about we avoid personal attacks and limit conversation to the topic.

      If you post reasoned argument why you think it is bad I will read it, I may then use with.my reason to agree or disagree with you.

    2. No, we simply are either experienced with nuclear power (such as myself), or have done enough research about nuclear power to be able to see past all of the fearmongering. Read some books and do some research and you might come to the same conclusions.

  22. The future of Nuclear power is fusion: there needs to be massive investment in research into different methods of achieving fusion, and harnessing the staggeringly huge amounts of power output.

    It’s been said that prototype fusion reactors could reach positive net gains within 20 – 50 years at current investment levels. I’d like to think that it would be possible in my lifetime.

    1. I don’t know how old you are, [Paulie], but I’m old enough to tell you that 30 years ago, people were saying that positive net energy from fusion would happen within 20-50 years at then-current investment levels.

      10 years ago, they were saying that positive net energy from fusion would be delayed because the investment levels were not kept up.

      Remember that once positive net energy is reached, there is still the matter of whether the cost per MWh produced can be made competitive with the future cost of wind and solar, which will have had decades of further technological development. (The alternatives are not going to stand still.)

      Meanwhile, humanity needs low carbon electricity generation now, and lots of it.

        1. With that much power you should be able to refrigerate the planet by using heat pumps to concentrate the energy into a volume and allow the heat to radiate to space, just need to make sure you are hot enough that it is in an energy range that is not reabsorbed by the atmosphere.
          With the right chemicals and mirrors you should be able to make it a laser :)

  23. We are currently reaching a level where solar and wind energy produce energy cheaper than nuclear, a mature technology, soon without subsidies, but sure, let’s go back to nuclear because of some start-up.

    1. Solar and wind are still very far away from being more cost-effective as a system, which includes all the external costs of grid balancing and energy storage – which simply don’t exist yet because nobody wants to pay the price to build grid upgrades and huge batteries. The renewable system exists in a state of greenwashing where the prices and LCOE are calculated a raw $/Watt of panels, or raw $/kWh at the panel output, and nobody counts how much it costs to actually have the power/energy at the point of distribution and user end.

      And many of the advocates are pulling smoke and mirrors by quoting solar power prices from Saudi Arabia, claiming that it costs such and so little – well guess what, most people don’t live at the equator!

        1. True, but by “majority” you mean about 60%, and thermal storage is pretty difficult to provide unless you live in a detached home – you need to put the storage boilers somewhere.

          1. And for a second point, most people aren’t heating with electricity anyways. They use natural gas, heating oil, wood, pellets… even surplus corn in some cases – electricity is actually very expensive for the purpose.

            That means the heating and hot water doesn’t really figure in to this problem. If anything, it makes the problem bigger because you’d have to produce even more renewable energy, which leads to greater swings in the output and the grid will need to be made even stronger to deal with the fluctuation.

  24. Living in a part of Bavaria where 30+ years after Chernobyl you still better don’t go foraging for mushrooms or eat wild boar (which like digging up and eating “pig truffle” mushrooms and mycelium very much), and where in some areas in the Oberland area of Upper Bavaria you better have no garden lot at all, I still say NO! to commercially operated nuclear power plants.

    commercial operation=constraint of cost cutting=lack of security=inevitable fail.
    As long as some MBA, CFO or CEO is judging $$$>>danger, desaster will strike.
    (even true for passenger aviation and any other techniques done by humans).

    If neglected, wind generators may burn, biogas generator gas collector domes may explode, a coal power plant may explode (which happened in 1987 just two villages from my home), but these do so locally. No terminators needed in order to get rid of the debris.

    The fallout from Mayak, Chernobyl, Fukushima and future such accidents spreads far over national borders, and I’m not aware of any compensations paid for decontamination. But in any case the administration responded by increasing the maximum allowed dose of exposure and/or complete resettlement for the local population, or letting the management get away with a deep bow.

    1. Have you ever thought about how far the fallout of the nuclear explosions at Mururoa atol went? I’m not even starting about the fallout of the 216 atmospheric nuclear explosions that happened above the U.S.

      Don’t worry too much about Mayak, Chernobyl or Fukushima. They’re just a drop in the ocean.

      I’m not saying that that’s any excuse to make it even worse… Just that there are much worse things that deserve worry.

    2. Google for Bhopal accident. Same year, 1986, but Chernobyl got the bigger press so everyone forgot Bhopal, even though over 1 million people were affected and the area is still poisoned today.

      There are conventional industrial accidents that spread pollution on the same scale – the difference is that nuclear fallout will eventually decay and dissappear. Chemical fallout will remain in the soil essentially forever, and it leaves only as it slowly washes into the ground water or runs off in the rivers – and you can’t detect it with a Geiger counter before you drink the water or eat the mushrooms.

      But radiation is more dangerous, right?

      1. I’d say equally dangerous.

        Both should be avoided.

        You could take the chemically polluted dirt and burn it (albeit no one will do it, too expensive).

        You cannot take radioactive soil and treat it, you have to cover it or dispose of it, or you have to wait, sometimes for generations. Not that much better, is it?
        Washout into ground water and deeper soil levels applies here too (now after 30+ years, the fallout from Chernobyl is beginning to reach the soil depth where the “pig truffle” mycelium lives, according to local hunters, the problem of radioactive wild boar is still increasing).

        In the chemical case the manufacturing of methyl isocyanate seems to have stopped.

        In the nuclear fission case new power plants are being built. Why?

  25. The article confuses moderator and control rod. The purpose of the moderator is to reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction. In other words the moderator facilitates the chain reaction. It is the control rods which absorb thermal neutrons and thus control the extent of the reaction

  26. Only 24M kwh?!
    I would have thought it would be more than 3 million times more productive than coal!
    It sure seems 3 million times easier to get 1kg of coal than uranium.
    Are you sure about those numbers?

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