36 ms·

Ultra Safe Nuclear

324 points by dongobongo 6y ago

teilo 6y ago
I'm all for the concept, but so far, everything I've seen has been nothing but concept.
- sambull 6y ago
  Large awesome graphic page on the fuel, and how its super safe. Nothing about how they 'conceptualize' disposing of their waste.
  - cj 6y ago
    The video on their homepage explains their approach to waste disposal. About 60 seconds into the video.
- dangerface 6y ago
  There are safe nuclear reactors like below that have been built and tested and proven to be commercially viable, but not of this specific design. https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reactor https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reacto...
xibalba 6y ago
Assuming nuclear truly can be ultra safe, how do you convince a public that has seen Chernobyl, Three Mile Island, and Fukushima to get on board? Particularly when the "competition" (solar, wind, etc) has such a strong tailwind.
- redm 6y ago
  1) I don't think its a zero sum game, nuclear doesn't preclude solar or wind. In-fact, thats how it's working now. Competition will drive improvements and optimization. 2) Accidents do happen with technology and the repercussions of nuclear accidents are serious. That doesn't mean we shouldn't re-think the technology and how it can be applied in a better or safer way, including cold fusion.
  - GuB-42 6y ago
    > I don't think its a zero sum game, nuclear doesn't preclude solar or wind. That's what I'd like to think, but it doesn't seem to be a good match. Nuclear plants want constant power output, they are ideal for base load. Solar and wind production vary during the day, and they don't always meet demand. That problem is called the "duck curve": too much is produced during the day and too little just after sunset. That's the reason why the best plants to complement solar and wind are those that can vary their output on demand. And unfortunately, that's typically coal (see Germany). Hydro would be ideal but its capacity depends is limited by the terrain.
    - jabl 6y ago
      > Nuclear plants want constant power output, they are ideal for base load. Solar and wind production vary during the day, and they don't always meet demand. That problem is called the "duck curve": too much is produced during the day and too little just after sunset. That's the reason why the best plants to complement solar and wind are those that can vary their output on demand. And unfortunately, that's typically coal (see Germany). Hydro would be ideal but its capacity depends is limited by the terrain. Modeling suggests there is a place for nuclear, or more generally, dispatchable (firm) low-carbon resources in deep decarbonized electricity grids. See e.g. https://doi.org/10.1016/j.joule.2018.08.006 https://doi.org/10.1016/j.joule.2018.08.006 As for the duck curve, you can flatten it with solar panels that are angled to the south-west rather than straight to the south, and some moderate amount of battery storage. That still leaves the problem of how to deal with the baseload. Nuclear could be a good candidate for that.
- dangerface 6y ago
  > (solar, wind, etc) has such a strong tailwind. Do they? I love renewables but for some reason the masses still just don't think you can get enough energy out of sky farts and hippy sun rays. The fact that ALL energy in our solar system comes from the sun is irrelevant the sun just doesn't feel very powerful. The public knows that nuclear is super powerful. > how do you convince a public that has seen Chernobyl, Three Mile Island, and Fukushima to get on board? The same way we convinced people to build them after Hiroshima. The same way we currently convince people to build coal plants when there are better alternatives. People want energy and they don't really care about the environmental / human cost.
  - aqme28 6y ago
    People aren't afraid of solar panels, and the tailwind probably refers to the fact that they're getting cheaper at an extremely rapid pace.
    - dangerface 6y ago
      People are afraid of having no energy, they think the sun is too weak to provide that energy and so we must burn things like coal, gas, oil, uranium whatever, see detritus reply as an example.
  - detritus 6y ago
    > The fact that ALL energy in our solar system comes from the sun is irrelevant Except human-made nuclear fission energy on Earth, somewhat ironically, given the thread.
    - aqme28 6y ago
      And geothermal.
      - dangerface 6y ago
        ahhh you got me thats the only other source of energy in our solar system but thats the exception that proves the rule.
- 3pt14159 6y ago
  Deaths per joule are the lowest out of any major fuel source except for maybe wind, which is debatable depending on your assumptions about the future.
  - rbecker 6y ago
    Sources on the deaths per joule claim: https://www.nextbigfuture.com/2011/03/deaths-per-twh-by-energy-source.html https://www.nextbigfuture.com/2011/03/deaths-per-twh-by-ener... https://energycentral.com/c/ec/deaths-nuclear-energy-compared-other-causes https://energycentral.com/c/ec/deaths-nuclear-energy-compare...
  - typeformer 6y ago
    Yeah perhaps but the tail risks are much higher.
  - rektide 6y ago
    Except... we don't know what the deaths are. It will take tens of thousands, hundreds of thousands of years to know what the death toll is from nuclear power. Because humanity is stuck with the waste for hundreds of thousands of years. We use only tiny amount of the energy available, then have waste to deal with through the ages. I'm in favor of nuclear, but wow are we ever terrible at innovating & trying to make a respectful, compelling go at it. Kerry shutting down the Integral Fast Reactor keeps coming back to haunt me as one of those strong indicators that America doesn't want to put itself up to the challenge of doing nuclear responsibly.
    - evgen 6y ago
      Out of curiosity, is there a single death that is directly attributable to nuclear waste from a reactor? (want to add that last clause because I do not think nukes should get blamed for someone improperly dumping medical equipment with cobalt or cesium isotope generators) For some reason I want to assume this happened at some point, maybe back in the 50s or 60s when we were really sloppy with nuclear waste but I can't seem to find any.
      - 6y ago
- manfredo 6y ago
  First, point out that Chernobyl, 3 Mile Island, and Fukushima amount to extremely small numbers of deaths relative to the power these plants generated. For three mile island and Fukushima this figure is zero among the public. Less than two dozen among the plant workers (all of which died due to the hydrogen explosion not radiation). The areas that were evacuated are now safe to return. Chernobyl was worse, but th Soviets didn't even bother with secondary containment. They didn't bother to put a concrete dome over the reactor. Even then, ~200 people died. This is a fairly small death toll for a worst-case failure. Contrast this with hydroelectricity, for example, which has resulted in the deaths of tena of thousands of people and the displacement of millions due to dam collapses [1]. Competition in the form of wind and solar are intermittent, requiring storage on a massive scale to offer a path to decarbonization. With 12 hours of energy storage, the US could reach 80% renewable generation. To get to 100% we need 3 weeks of storage according to estimates [2]. Currently, we have 8 seconds of battery storage compared to our 11.5 TWh daily electricity consumption. We have 4 minutes of hydroelectric storage, but hydroelectric storage is geographically limited. Increasing this by a factor of 180 is not feasible. In short, if the goal is decarbonization wind and solar don't actually present real competition. 1.https://en.m.wikipedia.org/wiki/Banqiao_Dam https://en.m.wikipedia.org/wiki/Banqiao_Dam 2. https://pv-magazine-usa.com/2018/03/01/12-hours-energy-storage-80-percent-wind-solar/ https://pv-magazine-usa.com/2018/03/01/12-hours-energy-stora...
  - shpeedy 6y ago
    You are joking about "small numbers of deaths", right?, because this millennia is not over yet.
    - blamestross 6y ago
      Coal and gas still kill a LOT more https://www.giss.nasa.gov/research/briefs/kharecha_02/ https://www.giss.nasa.gov/research/briefs/kharecha_02/ Less dramatically so do Solar and Wind just by increased rate of people falling off roofs and towers: https://www.statista.com/statistics/494425/death-rate-worldwide-by-energy-source/ https://www.statista.com/statistics/494425/death-rate-worldw...
  - 6y ago
- beefok 6y ago
  With the size constraint of that reactor (in volume), what's to say it would be used for the public? It could instead be the source of energy for a factory, or a data center for instance. I don't think we have to keep thinking about public use for these at all.
- steeve 6y ago
  How many deaths for Chernobyl, Three Mile Island and Fukushima? Would that number change your mind?
  - mdorazio 6y ago
    How many people with increased cancer rates from solar? Stop quoting deaths from nuclear accidents - the harm from nuclear incidents goes far beyond killing people outright.
    - V6HBGNQHU 6y ago
      How many people die from loosing power during winters and freezing to death? How many more would that be if everyone was using solar which can't provide enough power in winter?
      - quonn 6y ago
        I doubt anyone freezes to death in the EU, US, Australia, and Canada because of loosing power in winter.
        tonyarkles 6y ago
        > Canada Oh? I’m in Southern Saskatchewan, about two hours away from the US border. It reliably drops to -40 here in the winter. The vast majority of us heat our homes with natural gas furnaces, driven by electric fans. Long power outages in the winter are a very very big deal, and luckily are quite rare. A few years ago we had one that lasted about 12 hours, and the indoor temperature had dropped to about 7C. If it had continued to drop, the first thing would be damaged plumbing/flooding... followed by people who don’t have a large cache of warm clothes starting to have trouble. Edit: oh, yeah... https://en.wikipedia.org/wiki/January_1998_North_American_ice_storm https://en.wikipedia.org/wiki/January_1998_North_American_ic...
        V6HBGNQHU 6y ago
        > During 2006-2010, about 2,000 U.S. residents died each year from weather-related causes of death. About 31% of these deaths were attributed to exposure to excessive natural heat, heat stroke, sun stroke, or all; 63% were attributed to exposure to excessive natural cold, hypothermia, or both; https://pubmed.ncbi.nlm.nih.gov/25073563/ https://pubmed.ncbi.nlm.nih.gov/25073563/
- rurounijones 6y ago
  The US Navy has been successfully operating Nuclear Reactors without incident for decades in the harshest environments on earth [1] It can be done safely. https://www.mofa.go.jp/region/n-america/us/security/fact0604.pdf https://www.mofa.go.jp/region/n-america/us/security/fact0604...
  - Klinky 6y ago
    Apples to oranges. Reactor designs are completely different. They are basically set it and forget it designs that then require extremely costly refueling and refurbishment. Edit: I was wrong, the Ultra Safe Nuclear plan is somewhat similar. My comparison was with typical power grid reactor designs, not disposable reactors like what's being proposed.
    - wmf 6y ago
      That sounds exactly like the submission we're (supposed to be) discussing.
      - Klinky 6y ago
        You're actually right, in this case it is pretty comparable, so it's closer to apples to apples, which brings up concerns about costs and commercial viability of such a project, but that's not really point of this thread.
- jk700 6y ago
  In Ukraine, which lived through Chernobyl, public is mostly pro nuclear. Turns out solar and wind isn't actually competitive and nobody likes to pay rich "green energy" investors for no reason, so as long as they have no influence in the government and most mass media, it's pretty hard to convince people of the opposite - that they need to pay a lot more so that a tiny percentage of electricity could come from solar and wind [1]. [1] And even that is misleading and not in any way "greener", since solar and wind can't be used on demand it has to replace some energy, which in this case is nuclear energy, but it can replace only a small part of it, the rest will have to be replaced with something that can be generated on demand, like coal and gas.
  - flor1s 6y ago
    Is there a particular reason why solar and wind aren't competitive in Ukraine, while in general it seems like those technologies are some of the cheapest sources of energy available today?
    - lightgreen 6y ago
      > those technologies are some of the cheapest sources of energy available today? No they are not. They only work well at small percentage of generation when you have enough hydropower backup (effectively, batteries): generate from solar during day, and generate from hydro at night (or use fossil fuel backup). > solar In California large amount of electricity is consumed by air conditioners (4%). And they work very well together: on hot days you need more electricity for air conditioners, and on hot days solar generation works better. And you need more air conditioners during summer, and solar works better during summer. The opposite is true in Ukraine. They don't need air conditioners because summers are not too hot, but but they need to heat buildings at winter because winters are very cold (when solar is very poor) especially at nights (when solar does not exist). > wind You cannot place wind turbines anywhere. You need a place with a constant high wind (that's why offsore farms work better). I guess there are no such places in Ukraine. And still you need to have a hydro or fossil fuel backup, because wind itself cannot produce electricity constantly. > cheapest sources of energy available today They are cheapest because they are subsidised on one hand, and on the other hand, nuclear is penalized by lawsuits and regulartions and inspections (in the US; in Ukraine the economy barely grows, they don't build much new power plants).
- yongjik 6y ago
  Ever heard of Kessennuma [1]? You probably don't remember the name. When the 2011 Tohoku Earthquake hit, an oil tank ruptured, caught fire, and burnt for four days. According to [2], 1,152 people were killed, with additional 214 missing. That's a similar level as Fukushima's expected casualties, probably more. But nobody talks about Kessennuma, and nobody brings it up as an evidence that fossil fuels are an inherently dangerous technology that must be purged from the earth to protect our children. Because, apparently, dying in an oil fire is not scary enough. [1] https://en.wikipedia.org/wiki/Kesennuma https://en.wikipedia.org/wiki/Kesennuma [2] https://www.kesennuma-memorial.jp/english/ https://www.kesennuma-memorial.jp/english/
  - Klinky 6y ago
    Is the point you're trying to make that nuclear and fossil fuels can both be dangerous during a natural disaster? I don't think anyone will dispute this.
    - yongjik 6y ago
      Well, I guess most people don't, but then again, they don't dispute this in the same way folks say "All politicians are bad!" - and when they go to voting booth, they always pick a particular party of their choice. And they come back, and until the next election they keep saying "Bah, politics! All politicians are bad!" The majority of our energies are generated by fossil fuels, in most industrial countries. This has to stop - I think that's much more urgent than arguing between nuclear and renewables.
- Reedx 6y ago
  Data and statistics aren't getting through, so maybe the answer is to rebrand it. Drop the word "nuclear". Chernobyl is too powerful of an association. All the data in the world is just no match for that story and imagery.
  - EmilioMartinez 6y ago
    >rebrand it. Drop the word "nuclear". I laughed at the thought of A/B testing new names of fundamental forces across different demographics.
- option 6y ago
  I grew up near Chernobyl and my parents still work on Chernobyl power station. You actually don’t have to convince anyone there in the benefits of nuclear. Renewables are great but can’t meet 100% of demand. And when they can’t we should be using nuclear. As a CA resident now (who installed solar on my roof) it sickens me when our “leaders” scream “climate change” but close nuclear early and buy coal-generated electricity from Utah instead.
- loeg 6y ago
  Both the major incidents (Chernobyl and Fukushima) were reactors designed in the era of slide-rules. Neither is a 3rd or 4th generation design. Chernobyl was a bad design, and the incident resulted from Soviet mismanagement (keeping known RBMK reactor flaws secret) in tandem with local mismanagement (the test protocol was completely fucked). Fukushima required active cooling and could not cool itself using its own power output. And the backup generators were below sea level and the thing was on a fault line. Neither caused major loss of life. Three Mile Island was a scare, and did not cause significant damage or loss of life. Any newly constructed reactor would not have the design flaws of the Soviet RBMK and would be designed to fail-safe.
  - 7952 6y ago
    You haven't answered the question though. How do you get the public on board?
    - loeg 6y ago
      It'd help to stop repeating mostly false stories (and leading questions) about Chernobyl, Three Mile Island, and Fukushima every time nuclear comes up. But how to persuade the general public that science and statistics matter when even HN is skeptical? You're right, I don't know how to do that.
      - 7952 6y ago
        Science works because you are able to control most of the variables. It simplifies the world into something that can be modelled. Major decisions like energy policy are just more complicated than that. It is hundreds of overlapping considerations that have no good single answer. Yes science still matters, but there are deeper political questions at play. You just need to accept that if you want to build big complex things in the environment. Of course these kind of issues can often be ignored with sufficient political support. Which is exactly what wind and solar have done in Europe. Try using science to prove that a wind turbine isn't ugly. Or that it is worth killing some bird of prey to get clean energy. Try using science to explain why a coal miner should lose their livelihood. Or why you should stop eating so much red meat. It does not work. At the heart of this debate is not scepticism of science, but scepticism of scientists and engineers. Scepticism that they really are as good as they say they are.
- Udik 6y ago
  Just ask people if they think climate change is an existential threat. If they answer yes (as will most people who are opposed to nuclear energy) then ask them if they think nuclear energy is an existential threat too or just extremely dangerous. If the answer is "just extremely dangerous" then the choice is simple. Actually, I can't understand why all those who are predicting doomsday scenarios because of climate change aren't storming the streets with big pro-nuclear energy signs.
  - orthecreedence 6y ago
    > Actually, I can't understand why all those who are predicting doomsday scenarios because of climate change aren't storming the streets with big pro-nuclear energy signs. Agreed. Without being a primitivist, I don't think you can be both pro-environment and anti-nuclear at this point. Solar and wind just don't have the output to keep up with industry. If we're fine living in mud huts and it taking 6 months to produce a laptop, then fine (and honestly that might be the place we end up in 100 years). But as it is, solar and wind cannot sustain our current economy.
- commonturtle 6y ago
  This is the key question. Even if nuclear is made ultra safe, a single bad event (which is likely if we build hundreds of thousands of reactors world wide) can raise so much paranoia that future investments in nuclear can be affected. I have no idea how you could solve a problem like this.
VBprogrammer 6y ago
I once wondered if it would be possible to have a nuclear power station which operated subcritically with extra neutrons injected from an outside source. The advantage I saw was that turning off the outside source would instantly stop the reaction, no worrying about articulating fuel rods and poison injectors. Unfortunately decay heat is still an issue. Turns out it's potentially a thing but has some technical challenges.
- dangerface 6y ago
  As far as I know its not cost effective until the chain reaction starts so I don't think its possible to operate subcritically. Thorium reactors can essentially do this safe shutdown as the fuel is a liquid rather than a solid so you can just dump the fuel and stop the reaction.
- karpierz 6y ago
  How would you turn off the outside source, and how would the mechanism differ from existing safety features?
  - VBprogrammer 6y ago
    The Wikipedia page is a lot more detailed than I could hope to be, presumably you just turn off the power to the particle accelerator. Existing safety measures rely on some degree of integrity in the reactor at the time they are triggered. If it gets too damaged before the control rods are inserted it may not be possible to insert them. https://en.m.wikipedia.org/wiki/Subcritical_reactor#:~:text=A%20subcritical%20reactor%20is%20a,neutrons%20from%20an%20outside%20source https://en.m.wikipedia.org/wiki/Subcritical_reactor#:~:text=....
- Symmetry 6y ago
  The problem is less about preventing criticality and more about handling the decay heat from all the isotopes produced when it was critical. That's going to give you 10% of the heat you had been producing with the reactor on for a little while after you stop the chain reaction.
sandymcmurray 6y ago
Summary of discussion in this thread (from The West Wing) https://youtu.be/7fkMR96I0sw https://youtu.be/7fkMR96I0sw
grawprog 6y ago
So why has nuclear waste become a thing that's not mentioned anymore? It was a pretty big thing in the 90's, now it seems to get brushed under the rug for all this 'safe' nuclear power marketing. It's mot just meltdowns and containment breaches that are a problem with nuclear power. None of the renewable alternatives produce radioactive waste that needs to be stored and dealt with. https://en.m.wikipedia.org/wiki/Radioactive_waste https://en.m.wikipedia.org/wiki/Radioactive_waste >Exposure to radioactive waste may cause health impacts due to ionizing radiation exposure. In humans, a dose of 1 sievert carries a 5.5% risk of developing cancer,[12] and regulatory agencies assume the risk is linearly proportional to dose even for low doses. Ionizing radiation can cause deletions in chromosomes.[13]
- SparkyMcUnicorn 6y ago
  They address how they deal with the radioactive waste in the video.
- manfredo 6y ago
  Because it's not a problem. There's actually very little of it. It occupies a volume the footprint of a football field and 10 yards high [1]. Storing it is pretty foolproof: bury it in an area with no aquifer. The main risk of contamination is getting into the groundwater. If there's no groundwater the risk of contamination is eliminated even if the containers decay over time. And lastly, it doesn't make sense to bury our waste right now because some of the latest reactors being built can use this waste as fuel. We hold nuclear to an incredible double standard with respect to the waste it produces. Fossil fuels release substantially more radioactive waste [2], and that waste is poorly contained. Usually put in an exposed pile next to the plant, which occasionally spills into rivers nearby [3]. Not to mention a whole other host of pollutants like heavy metals, and the carbon dioxide that is th main driver of climate change. 1. https://www.energy.gov/ne/articles/5-fast-facts-about-spent-nuclear-fuel https://www.energy.gov/ne/articles/5-fast-facts-about-spent-... 2. https://www.scientificamerican.com/article/coal-ash-is-more-radioactive-than-nuclear-waste/ https://www.scientificamerican.com/article/coal-ash-is-more-... 3. https://en.m.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_fly_ash_slurry_spill https://en.m.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_f...
tyho 6y ago
The walk away passive safety is a tradeoff with non-proliferation concerns. This design requires 20% enrichment, much higher than traditional reactors. This might be a smart tradeoff, but let's not pretend it's doesn't exist. https://www.aps.org/units/fps/newsletters/201810/reactors.cfm https://www.aps.org/units/fps/newsletters/201810/reactors.cf...
- carry_bit 6y ago
  The countries in the nuclear club represent a significant fraction of the world's energy consumption. Even if they were the only ones to eliminate the use of carbon-based energy via nuclear, it would be a good start.
- jabl 6y ago
  We could start with taking anything said by Ed Lyman with a huge grain of salt, considering he's made an entire career out of concern-trolling anything related to nuclear power. In this case, his argument is basically that HALEU is a proliferation risk because given access to enrichment facilities, it's more effort to produce weapons-usable HEU starting from HALEU than from LEU or natural uranium. Well, duh! As he himself admits in that letter, it's only a modest factor of three difference for HALEU vs LEU. From a non-proliferation perspective, the critical thing is the access to enrichment technology in the first place! If one wants to make a case against HALEU, compare the economics vs. LEU.
nimish 6y ago
Safety is no longer the reason Nuclear is not worth it. The sun is a giant, free nuclear fusion plant in the sky. We can capture 1/5th of its output per square meter. For free! The wind -- caused by solar heating -- also generates free power. The cost of harvesting it is now so low, and will always continue to decline as any technology will, that any fuel-based generation mechanism is going to be rendered uneconomic with time alone. They depreciate faster as time goes on! Investing in any such generator needs to be for other reasons like land scarcity.
- gruez 6y ago
  >We can capture 1/5th of its output per square meter. For free! except you know, the solar panels. by the same logic you can you can capture fission power for free, all you need is set up the reactor.
  - deleted 6y ago
    [deleted]
  - crispyporkbites 6y ago
    Installing a solar panel can be done today, for a $100. Tomorrow it will be $50, and it’ll keep going down until the market dictates the price. Nuclear takes years to build and generate output, and the price is going up. It would be foolish to build a nuclear plant today unless you have a specific need for it (small location, little sunlight/wind). Personally I think that in 20-40 years time most people will get the bulk of their energy from local solar panels, with the grid, backed by a mix of renewables and existing non-renewable sources filling in all the gaps.
    - briffle 6y ago
      The whole point of this system is that its also quick to install, and cheap. Its not a custom designed for each mega site type of setup like traditional reactors. Solar is going to have fun in places like Alaska.
    - anoncareer0212 6y ago
user568439 6y ago
I want to see how safe is this underground graveyard in case of a volcanic eruption... I'm sorry but I don't believe in nuclear, I think at the pace renewable and batteries are evolving now, they will be better alternative before a new nuclear plant is planned and constructed which takes many years.
basemi 6y ago
Nice animation but but... I think nuclear is bad because the technology to make it is in the hands of a few big corps. That's the major downside, and of course, toxic waste.
- flyingfences 6y ago
  > the technology to make it is in the hands of a few big corps On a practical, mass-deployable scale, this is true of any power generation technology.
edge17 6y ago
Is this a company with a product or is this a concept?
nervousDev 6y ago
This reminds me of that guy that "invented" the microwave heater (for people) in the show Silicon Valley.
yabones 6y ago
For a more dense read, see the whitepaper[1] from Oak Ridge National Laboratory about FCM fuels, which seems to be one of the key innovations of this reactor type. Instead of using pellets of Uranium oxide directly inside the reactor, this method encapsulates the fuel in a high temperature ceramic material which makes it very unlikely for the reactor to 'melt down' the way that mainstream reactors can. [1] https://info.ornl.gov/sites/publications/Files/Pub42476.pdf https://info.ornl.gov/sites/publications/Files/Pub42476.pdf
ceilingcorner 6y ago
I find it a little odd that a site called Hacker News is so bullish on nuclear power. Could there be anything less hacker than a centralized, exclusively government owned and operated source of power? No thanks. I’d rather put more resources into solar, wind, and other sources of power that don’t depend on the government to not explode and irradiate the immediate area for hundreds of years.
- evgen 6y ago
  I think the site is bullish on nuclear power because it is overwhelmingly populated by reasonably educated people who are capable of performing risk analysis and understand cost/benefit tradeoffs. If you are looking for a herd of scared sheep who will parrot back whatever propaganda is being pushed by Greenpeace today I think you will have better luck over at Reddit.
  - adrianN 6y ago
    Note that the comment you're replying to is not talking about the dangers of nuclear power, but about the spirit of centralization vs diy hacking. I don't think the amount of vitriol in your comment is appropriate.
  - ceilingcorner 6y ago
    That doesn’t really address my comment, at all. These sort of strawman accusations of parroting propaganda are so bizarre. I don’t think I’ve read a single article or book by Greenpeace in my life. I genuinely have no idea what you are referring to.
    - sixstringtheory 6y ago
      Your original comment also commits some logical fallacies. You’re focusing on the label applied to the supposed users of HN, which is ad hominem. Then you employ a no true scotsman to tell them that they aren’t really hackers because they espouse a position that you deem non-hacker.
- deleted 6y ago
projektfu 6y ago
Is this a rebranding of the same modular reactor plans I read about 24 years ago? Why are they not being produced?
sradman 6y ago
At 5 MW, these MMR (Micro Modular Reactor) look like a specialized alternative to diesel generators servicing remote locations unserviced by the regular power grid. 20 year lifetime without refuelling is an attractive proposition if the capital costs are competitive.
hairytrog 6y ago
Two interesting things to see here, of many. They are really planning the sites to be temporary compared to the solar/wind/ and other industrial power plants that have little or no plan for returning their sites to the original virgin soil. And two, they seem to use a molten salt loop like in concentrated solar to meet variable demand without changing the power level of the reactor, which you can't really do because of Xenon poisoning. So it's like a natural gas plant in its ability to deliver power, but clean and holds 20 years of fuel inside the reactor.
- simonebrunozzi 6y ago
  > which you can't really do because of Xenon poisoning Can you clarify this part? You mean that channging the power level of the reactor would cause Xenon poisoning?
  - hairytrog 6y ago
    I highly recommend HBO's Chernobyl. Explains a lot this stuff. Basically, as a nuclear reactor operates, it is turning the Uranium into lots of other stuff. One component of this other stuff is Xenon-135, which absorbs neutrons and basically gets in the way of nuclear reactions. This is not an issue if you keep the reactor on because there are enough neutrons to keep things going and overcome the Xenon absorption. But if you turn the reactor off, you now have no neutrons from the fission reactions and lots of neutron absorbers. There is so much absorption that it's impossible to start up the reactor for a couple of days. That's why nuclear reactors operate at constant power and only turn off to refuel. This MMR also operates at constant power, which would also have benefits for cycling issues, and uses the molten salt loop to store heat and then use it when it's needed.
    - jacobr1 6y ago
      Ah, the the molten salt loop is like a flywheel?
      - phamilton 6y ago
hairytrog 6y ago
Seems like their claim to "Ultra Safe" is actually merited based on a first principles look at the power density. They claim 1.24 W/cm^3 versus 20-40 W/cm^3 in normal reactors. The high power densities mean you have to be able to cool the reactor, even when you shut down the reactor because reactors take a long time to actually turn off. With such low power density, it should be no problem to cool down the reactor. It'll just cool down naturally, like a hot pot. In fact the metric to look at would be power per core surface area.
- cbmuser 6y ago
  There are reactor types like the Integral Fast Reactor that will safely shut itself down even if the cooling systems fail. In fact, the engineers at Argonne deliberately tried to overheat the reactor by shutting off its pumps and they failed.
  - dongobongo 6y ago
    But they don’t lose the liquid coolant - which seems like a pretty reasonable scenario.
    - jabl 6y ago
      Especially considering the IFR (and it's predecessor EBR II where the experiment the parent refers to was done) are pool type reactors, meaning the reactor sits in a big pool filled with the primary coolant, there are no pipes where the primary coolant leaves the tank.
- jabl 6y ago
  It has low power density because it's a gas cooled reactor. Gas is a much worse heat conductor than a liquid. I'm slightly skeptical wrt gas cooled reactors. Due to the low power density, the reactor needs to be physically big. And since the gas is under high pressure, the reactor needs to be a pressure vessel. Big pressure vessel usually means expensive. One intriguing development is to use the TRISO kind of fuel that Ultra Safe has developed, but instead use molten salt as the coolant. That allows much higher power density, and doesn't need to be pressurized either as the operating temperature is well below the boiling point of the salt at atmospheric pressure. It also avoids the problem of having the fuel and highly radioactive and corrosive fission products dissolved in the salt, as molten salt reactors usually have.
mehmeta 6y ago
What would be the ballpark cost for this reactor producing 5MWe?
- OliverJones 6y ago
  It would be great to know the capital and ongoing maintenance cost per MWe of load, and the lifecycle cost per gWh. This product is pitched at remote sites, so presumably the costs aren't low enough (yet?) for places where power grid connection is an option.
Fooloo 6y ago
So North Korea getting nuclear weapons is a big deal and using every text book measure to prevent Iran from building these things is quite an effort. But providing the whole world with material which can be used to build these damn things is not a problem? Also there is big security problems all around the world due to terrorist. So how do we manage security with this small scale things?
thomasfromcdnjs 6y ago
Countries that go nuclear will have an advantage in the 21st century.
justinzollars 6y ago
I'd love to see these built in San Francisco. If we were serious about a Carbon free future we would build nuclear
bl0b 6y ago
Random renewable energy-related question that I've been thinking about: Specifically wrt solar, a big argument against is that it can't provide power during the night and we don't have a good way to store energy. What I'm wondering is why it's so imperative that residential/commercial properties are able to get full power from the grid 24/7? What if prices for power go way up during the night (because it can't come from solar), and people could just learn to get most of their power from the grid during the day? And have a relatively small per-house battery that charges during the day and can be used at night.
- deleted 6y ago
  [deleted]
- motorcycleman9 6y ago
  People prefer to not need to do that.
- philips 6y ago
  Many energy providers do this and they can provide back pressure to devices like smart thermostats. https://nest.com/energy-partners/ https://nest.com/energy-partners/ The industry for residential distributed energy resource systems and smart pricing is fairly nascent as far as I can tell though.
- sparkie 6y ago
  > What if prices for power go way up during the night Individual energy providers do not control prices. The market does. If there is market demand for energy at night, then people will fill in the gap to provide it. Anyone pushing up prices at night will have competition from someone else who will undercut them. They'll be forced to drop prices or lose customers. Batteries are inefficient, expensive, and do not provide an adequate amount of electricity for most purposes. Consider a UPS, they're about 90% efficient at most, and for all that 10% of wasted energy, you get to power your computer for about 15-60 minutes if the power is lost. The batteries only last a few years. Also, a bigger argument against solar (at least, photovoltaics) is that they use up rare earth metals, have limited lifetimes (<25 years), and then become non-recyclable toxic waste. Concentrating solar energy is more promising as a sustainable solution, but requires large infrastructure and the right climate to be cost effective.
walrus01 6y ago
Wasn't something very similar in size proposed for use in Alaska? https://en.wikipedia.org/wiki/Toshiba_4S https://en.wikipedia.org/wiki/Toshiba_4S
- hairytrog 6y ago
  Seems like they used a sodium coolant - great thermal properties as it allows for atmospheric pressure loop. But sodium introduces the chemical hazard and all the associated maintenance and materials woes and accident scenarios. Also, the power density on the 4S was relatively high.
  - hairytrog 6y ago
    also they used a strange control system. No control rods. Instead they moved the whole core up and down to change reactivity. wtf?
karlalexpauls 6y ago
Dr. Chris Morrison from USNC's space division presented to the Seattle Friends of Fission at Ada's https://youtu.be/39LGrJkDmho https://youtu.be/39LGrJkDmho
Lazare 6y ago
Eh. In my view, nuclear is very clearly safe enough, and has been for some time. What's more interesting to me is whether it's cheap enough.
- dongobongo 6y ago
  1% of commercial reactors Have failed catastrophically. Seems like terrible track record.
  - Lazare 6y ago
    > 1% of commercial reactors Have failed catastrophically. That seems a bit high to me. There have been a lot of commercial reactors. > Seems like terrible track record. Even if true, everything fails sometimes. Rooftop solar has a surprisingly high death rate from people falling off of roofs while installing it. Ultimately it's a question how safe nuclear is relative to other power methods, probably in terms of deaths per terawatt hour. And even counting those catastrophic failures, it turns out it's actually extremely safe. (...which really underscores just how horribly dangerous some of the alternatives are...) None of which means nuclear power is economic.
  - p1mrx 6y ago
    100% of fossil plants fail catastrophically; the catastrophe is just a bit slower.
  - dodobirdlord 6y ago
    Statista claims there are 440 nuclear power plants in operation today, and most of them probably have several reactors. So unless you're using some technical meaning of "commercial" that precludes things like Chinese SOE, I think the claim is just false.
  - fastball 6y ago
    No because now we have designs that cannot fail in the same way that 1% did.
Apofis 6y ago
"Ultra Safe" will come with Molten Salt Reactors. Hang tight until then. They can even safely reuse nuclear waste.
p1mrx 6y ago
Illinois EnergyProf recently did a video on USNC's design: https://www.youtube.com/watch?v=7gtog_gOaGQ https://www.youtube.com/watch?v=7gtog_gOaGQ (Though I think he used audio from the wrong microphone; the earlier videos sound much better.)
abalone 6y ago
Serious question: what happens when you take one of these fuel pellets and blow it up and disperse it in the atmosphere / water supply, either accidentally or on purpose? Have they actually designed a solution or is this a fundamental safety risk with all nuclear fuels? All I see addressed is proliferation / reprocessing which is a different thing.
- jabl 6y ago
  > Serious question: what happens when you take one of these fuel pellets and blow it up and disperse it in the atmosphere / water supply, either accidentally or on purpose? Hmm, nothing? There are already billions of tons of uranium dissolved in seawater (there are actually efforts to try to "mine" uranium from seawater), why would a few grams more matter? As for fission products, humanity has made hundreds of atmospheric nuclear tests, as well as the Chernobyl disaster that spewed lots of fission products into the atmoshpere. Unfortunate and stupid, yes, but not the end of humanity either. And fortunately, fission products decay away relatively quickly. So yes, a few grams of fission products from a spent fuel pellet will not make any impact if it's dispersed enough.
  - abalone 6y ago
    Chernobyl caused the near permanent evacuation of a nearby city, and nearly poisoned the water supply for millions. Not a good example if you’re trying to argue a release of fission products is no big deal. I would like to understand exactly if/how this reactor design gets around the risks inherent to explosions of radioactive fuel. If it’s not a problem then why does the marketing take pains to say it will never leave its capsule?
    - jabl 6y ago
      The question of you asked and which I answered was what if we take one fuel pellet and disperse it. I never said Chernobyl wasn't bad (heck, I called it a disaster for a reason!). But that was tons of spent fuel (rather than the few grams being contained in one fuel pellet) being blown out of the reactor building due to the steam explosion, or going up in smoke during the subsequent fires, and even that was far from the end of the world. In this case, I guess marketing takes pains, because one of the main ideas of this fuel type is to make them even safer, even during severe accident scenarios. Is it absolutely fool proof? Of course not; you shouldn't grind up the spent fuel and inhale the dust, for instance.
Animats 6y ago
What about graphite fires?
Gravityloss 6y ago
In the page it isn't explained how it shuts down passively in a loss of coolant event? Since the coolant is not doing moderation, removing it doesn't reduce reactivity at all. You have a 30 bar helium pressure vessel and heat exchangers etc. I wonder how much it's going to leak. Not saying it's bad, just interested in these questions. Some other designs have these issues in focus.
_def 6y ago
"ultra safe" seems a weird marketing term for me. "safe" should be enough, no? Unless they know that it isn't.

Ultra Safe Nuclear

324 points by dongobongo 6y ago

teilo 6y ago

I'm all for the concept, but so far, everything I've seen has been nothing but concept.

sambull 6y ago
Large awesome graphic page on the fuel, and how its super safe. Nothing about how they 'conceptualize' disposing of their waste.
- cj 6y ago
  The video on their homepage explains their approach to waste disposal. About 60 seconds into the video.
dangerface 6y ago
There are safe nuclear reactors like below that have been built and tested and proven to be commercially viable, but not of this specific design. https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reactor https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reacto...

xibalba 6y ago

Assuming nuclear truly can be ultra safe, how do you convince a public that has seen Chernobyl, Three Mile Island, and Fukushima to get on board? Particularly when the "competition" (solar, wind, etc) has such a strong tailwind.

redm 6y ago
1) I don't think its a zero sum game, nuclear doesn't preclude solar or wind. In-fact, thats how it's working now. Competition will drive improvements and optimization. 2) Accidents do happen with technology and the repercussions of nuclear accidents are serious. That doesn't mean we shouldn't re-think the technology and how it can be applied in a better or safer way, including cold fusion.
- GuB-42 6y ago
  > I don't think its a zero sum game, nuclear doesn't preclude solar or wind. That's what I'd like to think, but it doesn't seem to be a good match. Nuclear plants want constant power output, they are ideal for base load. Solar and wind production vary during the day, and they don't always meet demand. That problem is called the "duck curve": too much is produced during the day and too little just after sunset. That's the reason why the best plants to complement solar and wind are those that can vary their output on demand. And unfortunately, that's typically coal (see Germany). Hydro would be ideal but its capacity depends is limited by the terrain.
  - jabl 6y ago
    > Nuclear plants want constant power output, they are ideal for base load. Solar and wind production vary during the day, and they don't always meet demand. That problem is called the "duck curve": too much is produced during the day and too little just after sunset. That's the reason why the best plants to complement solar and wind are those that can vary their output on demand. And unfortunately, that's typically coal (see Germany). Hydro would be ideal but its capacity depends is limited by the terrain. Modeling suggests there is a place for nuclear, or more generally, dispatchable (firm) low-carbon resources in deep decarbonized electricity grids. See e.g. https://doi.org/10.1016/j.joule.2018.08.006 https://doi.org/10.1016/j.joule.2018.08.006 As for the duck curve, you can flatten it with solar panels that are angled to the south-west rather than straight to the south, and some moderate amount of battery storage. That still leaves the problem of how to deal with the baseload. Nuclear could be a good candidate for that.
dangerface 6y ago
> (solar, wind, etc) has such a strong tailwind. Do they? I love renewables but for some reason the masses still just don't think you can get enough energy out of sky farts and hippy sun rays. The fact that ALL energy in our solar system comes from the sun is irrelevant the sun just doesn't feel very powerful. The public knows that nuclear is super powerful. > how do you convince a public that has seen Chernobyl, Three Mile Island, and Fukushima to get on board? The same way we convinced people to build them after Hiroshima. The same way we currently convince people to build coal plants when there are better alternatives. People want energy and they don't really care about the environmental / human cost.
- aqme28 6y ago
  People aren't afraid of solar panels, and the tailwind probably refers to the fact that they're getting cheaper at an extremely rapid pace.
  - dangerface 6y ago
    People are afraid of having no energy, they think the sun is too weak to provide that energy and so we must burn things like coal, gas, oil, uranium whatever, see detritus reply as an example.
- detritus 6y ago
  > The fact that ALL energy in our solar system comes from the sun is irrelevant Except human-made nuclear fission energy on Earth, somewhat ironically, given the thread.
  - aqme28 6y ago
    And geothermal.
    - dangerface 6y ago
      ahhh you got me thats the only other source of energy in our solar system but thats the exception that proves the rule.
3pt14159 6y ago
Deaths per joule are the lowest out of any major fuel source except for maybe wind, which is debatable depending on your assumptions about the future.
- rbecker 6y ago
  Sources on the deaths per joule claim: https://www.nextbigfuture.com/2011/03/deaths-per-twh-by-energy-source.html https://www.nextbigfuture.com/2011/03/deaths-per-twh-by-ener... https://energycentral.com/c/ec/deaths-nuclear-energy-compared-other-causes https://energycentral.com/c/ec/deaths-nuclear-energy-compare...
- typeformer 6y ago
  Yeah perhaps but the tail risks are much higher.
- rektide 6y ago
  Except... we don't know what the deaths are. It will take tens of thousands, hundreds of thousands of years to know what the death toll is from nuclear power. Because humanity is stuck with the waste for hundreds of thousands of years. We use only tiny amount of the energy available, then have waste to deal with through the ages. I'm in favor of nuclear, but wow are we ever terrible at innovating & trying to make a respectful, compelling go at it. Kerry shutting down the Integral Fast Reactor keeps coming back to haunt me as one of those strong indicators that America doesn't want to put itself up to the challenge of doing nuclear responsibly.
  - evgen 6y ago
    Out of curiosity, is there a single death that is directly attributable to nuclear waste from a reactor? (want to add that last clause because I do not think nukes should get blamed for someone improperly dumping medical equipment with cobalt or cesium isotope generators) For some reason I want to assume this happened at some point, maybe back in the 50s or 60s when we were really sloppy with nuclear waste but I can't seem to find any.
    - 6y ago
manfredo 6y ago
First, point out that Chernobyl, 3 Mile Island, and Fukushima amount to extremely small numbers of deaths relative to the power these plants generated. For three mile island and Fukushima this figure is zero among the public. Less than two dozen among the plant workers (all of which died due to the hydrogen explosion not radiation). The areas that were evacuated are now safe to return. Chernobyl was worse, but th Soviets didn't even bother with secondary containment. They didn't bother to put a concrete dome over the reactor. Even then, ~200 people died. This is a fairly small death toll for a worst-case failure. Contrast this with hydroelectricity, for example, which has resulted in the deaths of tena of thousands of people and the displacement of millions due to dam collapses [1]. Competition in the form of wind and solar are intermittent, requiring storage on a massive scale to offer a path to decarbonization. With 12 hours of energy storage, the US could reach 80% renewable generation. To get to 100% we need 3 weeks of storage according to estimates [2]. Currently, we have 8 seconds of battery storage compared to our 11.5 TWh daily electricity consumption. We have 4 minutes of hydroelectric storage, but hydroelectric storage is geographically limited. Increasing this by a factor of 180 is not feasible. In short, if the goal is decarbonization wind and solar don't actually present real competition. 1.https://en.m.wikipedia.org/wiki/Banqiao_Dam https://en.m.wikipedia.org/wiki/Banqiao_Dam 2. https://pv-magazine-usa.com/2018/03/01/12-hours-energy-storage-80-percent-wind-solar/ https://pv-magazine-usa.com/2018/03/01/12-hours-energy-stora...
- shpeedy 6y ago
  You are joking about "small numbers of deaths", right?, because this millennia is not over yet.
  - blamestross 6y ago
    Coal and gas still kill a LOT more https://www.giss.nasa.gov/research/briefs/kharecha_02/ https://www.giss.nasa.gov/research/briefs/kharecha_02/ Less dramatically so do Solar and Wind just by increased rate of people falling off roofs and towers: https://www.statista.com/statistics/494425/death-rate-worldwide-by-energy-source/ https://www.statista.com/statistics/494425/death-rate-worldw...
- 6y ago
beefok 6y ago
With the size constraint of that reactor (in volume), what's to say it would be used for the public? It could instead be the source of energy for a factory, or a data center for instance. I don't think we have to keep thinking about public use for these at all.
steeve 6y ago
How many deaths for Chernobyl, Three Mile Island and Fukushima? Would that number change your mind?
- mdorazio 6y ago
  How many people with increased cancer rates from solar? Stop quoting deaths from nuclear accidents - the harm from nuclear incidents goes far beyond killing people outright.
  - V6HBGNQHU 6y ago
    How many people die from loosing power during winters and freezing to death? How many more would that be if everyone was using solar which can't provide enough power in winter?
    - quonn 6y ago
      I doubt anyone freezes to death in the EU, US, Australia, and Canada because of loosing power in winter.
      - tonyarkles 6y ago
        > Canada Oh? I’m in Southern Saskatchewan, about two hours away from the US border. It reliably drops to -40 here in the winter. The vast majority of us heat our homes with natural gas furnaces, driven by electric fans. Long power outages in the winter are a very very big deal, and luckily are quite rare. A few years ago we had one that lasted about 12 hours, and the indoor temperature had dropped to about 7C. If it had continued to drop, the first thing would be damaged plumbing/flooding... followed by people who don’t have a large cache of warm clothes starting to have trouble. Edit: oh, yeah... https://en.wikipedia.org/wiki/January_1998_North_American_ice_storm https://en.wikipedia.org/wiki/January_1998_North_American_ic...
      - V6HBGNQHU 6y ago
        > During 2006-2010, about 2,000 U.S. residents died each year from weather-related causes of death. About 31% of these deaths were attributed to exposure to excessive natural heat, heat stroke, sun stroke, or all; 63% were attributed to exposure to excessive natural cold, hypothermia, or both; https://pubmed.ncbi.nlm.nih.gov/25073563/ https://pubmed.ncbi.nlm.nih.gov/25073563/
rurounijones 6y ago
The US Navy has been successfully operating Nuclear Reactors without incident for decades in the harshest environments on earth [1] It can be done safely. https://www.mofa.go.jp/region/n-america/us/security/fact0604.pdf https://www.mofa.go.jp/region/n-america/us/security/fact0604...
- Klinky 6y ago
  Apples to oranges. Reactor designs are completely different. They are basically set it and forget it designs that then require extremely costly refueling and refurbishment. Edit: I was wrong, the Ultra Safe Nuclear plan is somewhat similar. My comparison was with typical power grid reactor designs, not disposable reactors like what's being proposed.
  - wmf 6y ago
    That sounds exactly like the submission we're (supposed to be) discussing.
    - Klinky 6y ago
      You're actually right, in this case it is pretty comparable, so it's closer to apples to apples, which brings up concerns about costs and commercial viability of such a project, but that's not really point of this thread.
jk700 6y ago
In Ukraine, which lived through Chernobyl, public is mostly pro nuclear. Turns out solar and wind isn't actually competitive and nobody likes to pay rich "green energy" investors for no reason, so as long as they have no influence in the government and most mass media, it's pretty hard to convince people of the opposite - that they need to pay a lot more so that a tiny percentage of electricity could come from solar and wind [1]. [1] And even that is misleading and not in any way "greener", since solar and wind can't be used on demand it has to replace some energy, which in this case is nuclear energy, but it can replace only a small part of it, the rest will have to be replaced with something that can be generated on demand, like coal and gas.
- flor1s 6y ago
  Is there a particular reason why solar and wind aren't competitive in Ukraine, while in general it seems like those technologies are some of the cheapest sources of energy available today?
  - lightgreen 6y ago
    > those technologies are some of the cheapest sources of energy available today? No they are not. They only work well at small percentage of generation when you have enough hydropower backup (effectively, batteries): generate from solar during day, and generate from hydro at night (or use fossil fuel backup). > solar In California large amount of electricity is consumed by air conditioners (4%). And they work very well together: on hot days you need more electricity for air conditioners, and on hot days solar generation works better. And you need more air conditioners during summer, and solar works better during summer. The opposite is true in Ukraine. They don't need air conditioners because summers are not too hot, but but they need to heat buildings at winter because winters are very cold (when solar is very poor) especially at nights (when solar does not exist). > wind You cannot place wind turbines anywhere. You need a place with a constant high wind (that's why offsore farms work better). I guess there are no such places in Ukraine. And still you need to have a hydro or fossil fuel backup, because wind itself cannot produce electricity constantly. > cheapest sources of energy available today They are cheapest because they are subsidised on one hand, and on the other hand, nuclear is penalized by lawsuits and regulartions and inspections (in the US; in Ukraine the economy barely grows, they don't build much new power plants).
yongjik 6y ago
Ever heard of Kessennuma [1]? You probably don't remember the name. When the 2011 Tohoku Earthquake hit, an oil tank ruptured, caught fire, and burnt for four days. According to [2], 1,152 people were killed, with additional 214 missing. That's a similar level as Fukushima's expected casualties, probably more. But nobody talks about Kessennuma, and nobody brings it up as an evidence that fossil fuels are an inherently dangerous technology that must be purged from the earth to protect our children. Because, apparently, dying in an oil fire is not scary enough. [1] https://en.wikipedia.org/wiki/Kesennuma https://en.wikipedia.org/wiki/Kesennuma [2] https://www.kesennuma-memorial.jp/english/ https://www.kesennuma-memorial.jp/english/
- Klinky 6y ago
  Is the point you're trying to make that nuclear and fossil fuels can both be dangerous during a natural disaster? I don't think anyone will dispute this.
  - yongjik 6y ago
    Well, I guess most people don't, but then again, they don't dispute this in the same way folks say "All politicians are bad!" - and when they go to voting booth, they always pick a particular party of their choice. And they come back, and until the next election they keep saying "Bah, politics! All politicians are bad!" The majority of our energies are generated by fossil fuels, in most industrial countries. This has to stop - I think that's much more urgent than arguing between nuclear and renewables.
Reedx 6y ago
Data and statistics aren't getting through, so maybe the answer is to rebrand it. Drop the word "nuclear". Chernobyl is too powerful of an association. All the data in the world is just no match for that story and imagery.
- EmilioMartinez 6y ago
  >rebrand it. Drop the word "nuclear". I laughed at the thought of A/B testing new names of fundamental forces across different demographics.
option 6y ago
I grew up near Chernobyl and my parents still work on Chernobyl power station. You actually don’t have to convince anyone there in the benefits of nuclear. Renewables are great but can’t meet 100% of demand. And when they can’t we should be using nuclear. As a CA resident now (who installed solar on my roof) it sickens me when our “leaders” scream “climate change” but close nuclear early and buy coal-generated electricity from Utah instead.
loeg 6y ago
Both the major incidents (Chernobyl and Fukushima) were reactors designed in the era of slide-rules. Neither is a 3rd or 4th generation design. Chernobyl was a bad design, and the incident resulted from Soviet mismanagement (keeping known RBMK reactor flaws secret) in tandem with local mismanagement (the test protocol was completely fucked). Fukushima required active cooling and could not cool itself using its own power output. And the backup generators were below sea level and the thing was on a fault line. Neither caused major loss of life. Three Mile Island was a scare, and did not cause significant damage or loss of life. Any newly constructed reactor would not have the design flaws of the Soviet RBMK and would be designed to fail-safe.
- 7952 6y ago
  You haven't answered the question though. How do you get the public on board?
  - loeg 6y ago
    It'd help to stop repeating mostly false stories (and leading questions) about Chernobyl, Three Mile Island, and Fukushima every time nuclear comes up. But how to persuade the general public that science and statistics matter when even HN is skeptical? You're right, I don't know how to do that.
    - 7952 6y ago
      Science works because you are able to control most of the variables. It simplifies the world into something that can be modelled. Major decisions like energy policy are just more complicated than that. It is hundreds of overlapping considerations that have no good single answer. Yes science still matters, but there are deeper political questions at play. You just need to accept that if you want to build big complex things in the environment. Of course these kind of issues can often be ignored with sufficient political support. Which is exactly what wind and solar have done in Europe. Try using science to prove that a wind turbine isn't ugly. Or that it is worth killing some bird of prey to get clean energy. Try using science to explain why a coal miner should lose their livelihood. Or why you should stop eating so much red meat. It does not work. At the heart of this debate is not scepticism of science, but scepticism of scientists and engineers. Scepticism that they really are as good as they say they are.
Udik 6y ago
Just ask people if they think climate change is an existential threat. If they answer yes (as will most people who are opposed to nuclear energy) then ask them if they think nuclear energy is an existential threat too or just extremely dangerous. If the answer is "just extremely dangerous" then the choice is simple. Actually, I can't understand why all those who are predicting doomsday scenarios because of climate change aren't storming the streets with big pro-nuclear energy signs.
- orthecreedence 6y ago
  > Actually, I can't understand why all those who are predicting doomsday scenarios because of climate change aren't storming the streets with big pro-nuclear energy signs. Agreed. Without being a primitivist, I don't think you can be both pro-environment and anti-nuclear at this point. Solar and wind just don't have the output to keep up with industry. If we're fine living in mud huts and it taking 6 months to produce a laptop, then fine (and honestly that might be the place we end up in 100 years). But as it is, solar and wind cannot sustain our current economy.
commonturtle 6y ago
This is the key question. Even if nuclear is made ultra safe, a single bad event (which is likely if we build hundreds of thousands of reactors world wide) can raise so much paranoia that future investments in nuclear can be affected. I have no idea how you could solve a problem like this.

VBprogrammer 6y ago

I once wondered if it would be possible to have a nuclear power station which operated subcritically with extra neutrons injected from an outside source. The advantage I saw was that turning off the outside source would instantly stop the reaction, no worrying about articulating fuel rods and poison injectors. Unfortunately decay heat is still an issue. Turns out it's potentially a thing but has some technical challenges.

dangerface 6y ago
As far as I know its not cost effective until the chain reaction starts so I don't think its possible to operate subcritically. Thorium reactors can essentially do this safe shutdown as the fuel is a liquid rather than a solid so you can just dump the fuel and stop the reaction.
karpierz 6y ago
How would you turn off the outside source, and how would the mechanism differ from existing safety features?
- VBprogrammer 6y ago
  The Wikipedia page is a lot more detailed than I could hope to be, presumably you just turn off the power to the particle accelerator. Existing safety measures rely on some degree of integrity in the reactor at the time they are triggered. If it gets too damaged before the control rods are inserted it may not be possible to insert them. https://en.m.wikipedia.org/wiki/Subcritical_reactor#:~:text=A%20subcritical%20reactor%20is%20a,neutrons%20from%20an%20outside%20source https://en.m.wikipedia.org/wiki/Subcritical_reactor#:~:text=....
Symmetry 6y ago
The problem is less about preventing criticality and more about handling the decay heat from all the isotopes produced when it was critical. That's going to give you 10% of the heat you had been producing with the reactor on for a little while after you stop the chain reaction.

sandymcmurray 6y ago

Summary of discussion in this thread (from The West Wing) https://youtu.be/7fkMR96I0sw https://youtu.be/7fkMR96I0sw

grawprog 6y ago

So why has nuclear waste become a thing that's not mentioned anymore? It was a pretty big thing in the 90's, now it seems to get brushed under the rug for all this 'safe' nuclear power marketing. It's mot just meltdowns and containment breaches that are a problem with nuclear power. None of the renewable alternatives produce radioactive waste that needs to be stored and dealt with. https://en.m.wikipedia.org/wiki/Radioactive_waste https://en.m.wikipedia.org/wiki/Radioactive_waste >Exposure to radioactive waste may cause health impacts due to ionizing radiation exposure. In humans, a dose of 1 sievert carries a 5.5% risk of developing cancer,[12] and regulatory agencies assume the risk is linearly proportional to dose even for low doses. Ionizing radiation can cause deletions in chromosomes.[13]

SparkyMcUnicorn 6y ago
They address how they deal with the radioactive waste in the video.
manfredo 6y ago
Because it's not a problem. There's actually very little of it. It occupies a volume the footprint of a football field and 10 yards high [1]. Storing it is pretty foolproof: bury it in an area with no aquifer. The main risk of contamination is getting into the groundwater. If there's no groundwater the risk of contamination is eliminated even if the containers decay over time. And lastly, it doesn't make sense to bury our waste right now because some of the latest reactors being built can use this waste as fuel. We hold nuclear to an incredible double standard with respect to the waste it produces. Fossil fuels release substantially more radioactive waste [2], and that waste is poorly contained. Usually put in an exposed pile next to the plant, which occasionally spills into rivers nearby [3]. Not to mention a whole other host of pollutants like heavy metals, and the carbon dioxide that is th main driver of climate change. 1. https://www.energy.gov/ne/articles/5-fast-facts-about-spent-nuclear-fuel https://www.energy.gov/ne/articles/5-fast-facts-about-spent-... 2. https://www.scientificamerican.com/article/coal-ash-is-more-radioactive-than-nuclear-waste/ https://www.scientificamerican.com/article/coal-ash-is-more-... 3. https://en.m.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_fly_ash_slurry_spill https://en.m.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_f...

tyho 6y ago

The walk away passive safety is a tradeoff with non-proliferation concerns. This design requires 20% enrichment, much higher than traditional reactors. This might be a smart tradeoff, but let's not pretend it's doesn't exist. https://www.aps.org/units/fps/newsletters/201810/reactors.cfm https://www.aps.org/units/fps/newsletters/201810/reactors.cf...

carry_bit 6y ago
The countries in the nuclear club represent a significant fraction of the world's energy consumption. Even if they were the only ones to eliminate the use of carbon-based energy via nuclear, it would be a good start.
jabl 6y ago
We could start with taking anything said by Ed Lyman with a huge grain of salt, considering he's made an entire career out of concern-trolling anything related to nuclear power. In this case, his argument is basically that HALEU is a proliferation risk because given access to enrichment facilities, it's more effort to produce weapons-usable HEU starting from HALEU than from LEU or natural uranium. Well, duh! As he himself admits in that letter, it's only a modest factor of three difference for HALEU vs LEU. From a non-proliferation perspective, the critical thing is the access to enrichment technology in the first place! If one wants to make a case against HALEU, compare the economics vs. LEU.

nimish 6y ago

Safety is no longer the reason Nuclear is not worth it. The sun is a giant, free nuclear fusion plant in the sky. We can capture 1/5th of its output per square meter. For free! The wind -- caused by solar heating -- also generates free power. The cost of harvesting it is now so low, and will always continue to decline as any technology will, that any fuel-based generation mechanism is going to be rendered uneconomic with time alone. They depreciate faster as time goes on! Investing in any such generator needs to be for other reasons like land scarcity.

gruez 6y ago
>We can capture 1/5th of its output per square meter. For free! except you know, the solar panels. by the same logic you can you can capture fission power for free, all you need is set up the reactor.
- deleted 6y ago
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- crispyporkbites 6y ago
  Installing a solar panel can be done today, for a $100. Tomorrow it will be $50, and it’ll keep going down until the market dictates the price. Nuclear takes years to build and generate output, and the price is going up. It would be foolish to build a nuclear plant today unless you have a specific need for it (small location, little sunlight/wind). Personally I think that in 20-40 years time most people will get the bulk of their energy from local solar panels, with the grid, backed by a mix of renewables and existing non-renewable sources filling in all the gaps.
  - briffle 6y ago
    The whole point of this system is that its also quick to install, and cheap. Its not a custom designed for each mega site type of setup like traditional reactors. Solar is going to have fun in places like Alaska.
  - anoncareer0212 6y ago

user568439 6y ago

I want to see how safe is this underground graveyard in case of a volcanic eruption... I'm sorry but I don't believe in nuclear, I think at the pace renewable and batteries are evolving now, they will be better alternative before a new nuclear plant is planned and constructed which takes many years.

basemi 6y ago

Nice animation but but... I think nuclear is bad because the technology to make it is in the hands of a few big corps. That's the major downside, and of course, toxic waste.

flyingfences 6y ago
> the technology to make it is in the hands of a few big corps On a practical, mass-deployable scale, this is true of any power generation technology.

edge17 6y ago

Is this a company with a product or is this a concept?

nervousDev 6y ago

This reminds me of that guy that "invented" the microwave heater (for people) in the show Silicon Valley.

yabones 6y ago

For a more dense read, see the whitepaper[1] from Oak Ridge National Laboratory about FCM fuels, which seems to be one of the key innovations of this reactor type. Instead of using pellets of Uranium oxide directly inside the reactor, this method encapsulates the fuel in a high temperature ceramic material which makes it very unlikely for the reactor to 'melt down' the way that mainstream reactors can. [1] https://info.ornl.gov/sites/publications/Files/Pub42476.pdf https://info.ornl.gov/sites/publications/Files/Pub42476.pdf

ceilingcorner 6y ago

I find it a little odd that a site called Hacker News is so bullish on nuclear power. Could there be anything less hacker than a centralized, exclusively government owned and operated source of power? No thanks. I’d rather put more resources into solar, wind, and other sources of power that don’t depend on the government to not explode and irradiate the immediate area for hundreds of years.

evgen 6y ago
I think the site is bullish on nuclear power because it is overwhelmingly populated by reasonably educated people who are capable of performing risk analysis and understand cost/benefit tradeoffs. If you are looking for a herd of scared sheep who will parrot back whatever propaganda is being pushed by Greenpeace today I think you will have better luck over at Reddit.
- adrianN 6y ago
  Note that the comment you're replying to is not talking about the dangers of nuclear power, but about the spirit of centralization vs diy hacking. I don't think the amount of vitriol in your comment is appropriate.
- ceilingcorner 6y ago
  That doesn’t really address my comment, at all. These sort of strawman accusations of parroting propaganda are so bizarre. I don’t think I’ve read a single article or book by Greenpeace in my life. I genuinely have no idea what you are referring to.
  - sixstringtheory 6y ago
    Your original comment also commits some logical fallacies. You’re focusing on the label applied to the supposed users of HN, which is ad hominem. Then you employ a no true scotsman to tell them that they aren’t really hackers because they espouse a position that you deem non-hacker.
deleted 6y ago

projektfu 6y ago

Is this a rebranding of the same modular reactor plans I read about 24 years ago? Why are they not being produced?

sradman 6y ago

At 5 MW, these MMR (Micro Modular Reactor) look like a specialized alternative to diesel generators servicing remote locations unserviced by the regular power grid. 20 year lifetime without refuelling is an attractive proposition if the capital costs are competitive.

hairytrog 6y ago

Two interesting things to see here, of many. They are really planning the sites to be temporary compared to the solar/wind/ and other industrial power plants that have little or no plan for returning their sites to the original virgin soil. And two, they seem to use a molten salt loop like in concentrated solar to meet variable demand without changing the power level of the reactor, which you can't really do because of Xenon poisoning. So it's like a natural gas plant in its ability to deliver power, but clean and holds 20 years of fuel inside the reactor.

simonebrunozzi 6y ago
> which you can't really do because of Xenon poisoning Can you clarify this part? You mean that channging the power level of the reactor would cause Xenon poisoning?
- hairytrog 6y ago
  I highly recommend HBO's Chernobyl. Explains a lot this stuff. Basically, as a nuclear reactor operates, it is turning the Uranium into lots of other stuff. One component of this other stuff is Xenon-135, which absorbs neutrons and basically gets in the way of nuclear reactions. This is not an issue if you keep the reactor on because there are enough neutrons to keep things going and overcome the Xenon absorption. But if you turn the reactor off, you now have no neutrons from the fission reactions and lots of neutron absorbers. There is so much absorption that it's impossible to start up the reactor for a couple of days. That's why nuclear reactors operate at constant power and only turn off to refuel. This MMR also operates at constant power, which would also have benefits for cycling issues, and uses the molten salt loop to store heat and then use it when it's needed.
  - jacobr1 6y ago
    Ah, the the molten salt loop is like a flywheel?
    - phamilton 6y ago

hairytrog 6y ago

Seems like their claim to "Ultra Safe" is actually merited based on a first principles look at the power density. They claim 1.24 W/cm^3 versus 20-40 W/cm^3 in normal reactors. The high power densities mean you have to be able to cool the reactor, even when you shut down the reactor because reactors take a long time to actually turn off. With such low power density, it should be no problem to cool down the reactor. It'll just cool down naturally, like a hot pot. In fact the metric to look at would be power per core surface area.

cbmuser 6y ago
There are reactor types like the Integral Fast Reactor that will safely shut itself down even if the cooling systems fail. In fact, the engineers at Argonne deliberately tried to overheat the reactor by shutting off its pumps and they failed.
- dongobongo 6y ago
  But they don’t lose the liquid coolant - which seems like a pretty reasonable scenario.
  - jabl 6y ago
    Especially considering the IFR (and it's predecessor EBR II where the experiment the parent refers to was done) are pool type reactors, meaning the reactor sits in a big pool filled with the primary coolant, there are no pipes where the primary coolant leaves the tank.
jabl 6y ago
It has low power density because it's a gas cooled reactor. Gas is a much worse heat conductor than a liquid. I'm slightly skeptical wrt gas cooled reactors. Due to the low power density, the reactor needs to be physically big. And since the gas is under high pressure, the reactor needs to be a pressure vessel. Big pressure vessel usually means expensive. One intriguing development is to use the TRISO kind of fuel that Ultra Safe has developed, but instead use molten salt as the coolant. That allows much higher power density, and doesn't need to be pressurized either as the operating temperature is well below the boiling point of the salt at atmospheric pressure. It also avoids the problem of having the fuel and highly radioactive and corrosive fission products dissolved in the salt, as molten salt reactors usually have.

mehmeta 6y ago

What would be the ballpark cost for this reactor producing 5MWe?

OliverJones 6y ago
It would be great to know the capital and ongoing maintenance cost per MWe of load, and the lifecycle cost per gWh. This product is pitched at remote sites, so presumably the costs aren't low enough (yet?) for places where power grid connection is an option.

Fooloo 6y ago

So North Korea getting nuclear weapons is a big deal and using every text book measure to prevent Iran from building these things is quite an effort. But providing the whole world with material which can be used to build these damn things is not a problem? Also there is big security problems all around the world due to terrorist. So how do we manage security with this small scale things?

thomasfromcdnjs 6y ago

Countries that go nuclear will have an advantage in the 21st century.

justinzollars 6y ago

I'd love to see these built in San Francisco. If we were serious about a Carbon free future we would build nuclear

bl0b 6y ago

Random renewable energy-related question that I've been thinking about: Specifically wrt solar, a big argument against is that it can't provide power during the night and we don't have a good way to store energy. What I'm wondering is why it's so imperative that residential/commercial properties are able to get full power from the grid 24/7? What if prices for power go way up during the night (because it can't come from solar), and people could just learn to get most of their power from the grid during the day? And have a relatively small per-house battery that charges during the day and can be used at night.

deleted 6y ago
[deleted]
motorcycleman9 6y ago
People prefer to not need to do that.
philips 6y ago
Many energy providers do this and they can provide back pressure to devices like smart thermostats. https://nest.com/energy-partners/ https://nest.com/energy-partners/ The industry for residential distributed energy resource systems and smart pricing is fairly nascent as far as I can tell though.
sparkie 6y ago
> What if prices for power go way up during the night Individual energy providers do not control prices. The market does. If there is market demand for energy at night, then people will fill in the gap to provide it. Anyone pushing up prices at night will have competition from someone else who will undercut them. They'll be forced to drop prices or lose customers. Batteries are inefficient, expensive, and do not provide an adequate amount of electricity for most purposes. Consider a UPS, they're about 90% efficient at most, and for all that 10% of wasted energy, you get to power your computer for about 15-60 minutes if the power is lost. The batteries only last a few years. Also, a bigger argument against solar (at least, photovoltaics) is that they use up rare earth metals, have limited lifetimes (<25 years), and then become non-recyclable toxic waste. Concentrating solar energy is more promising as a sustainable solution, but requires large infrastructure and the right climate to be cost effective.

walrus01 6y ago

Wasn't something very similar in size proposed for use in Alaska? https://en.wikipedia.org/wiki/Toshiba_4S https://en.wikipedia.org/wiki/Toshiba_4S

hairytrog 6y ago
Seems like they used a sodium coolant - great thermal properties as it allows for atmospheric pressure loop. But sodium introduces the chemical hazard and all the associated maintenance and materials woes and accident scenarios. Also, the power density on the 4S was relatively high.
- hairytrog 6y ago
  also they used a strange control system. No control rods. Instead they moved the whole core up and down to change reactivity. wtf?

karlalexpauls 6y ago

Dr. Chris Morrison from USNC's space division presented to the Seattle Friends of Fission at Ada's https://youtu.be/39LGrJkDmho https://youtu.be/39LGrJkDmho

Lazare 6y ago

Eh. In my view, nuclear is very clearly safe enough, and has been for some time. What's more interesting to me is whether it's cheap enough.

dongobongo 6y ago
1% of commercial reactors Have failed catastrophically. Seems like terrible track record.
- Lazare 6y ago
  > 1% of commercial reactors Have failed catastrophically. That seems a bit high to me. There have been a lot of commercial reactors. > Seems like terrible track record. Even if true, everything fails sometimes. Rooftop solar has a surprisingly high death rate from people falling off of roofs while installing it. Ultimately it's a question how safe nuclear is relative to other power methods, probably in terms of deaths per terawatt hour. And even counting those catastrophic failures, it turns out it's actually extremely safe. (...which really underscores just how horribly dangerous some of the alternatives are...) None of which means nuclear power is economic.
- p1mrx 6y ago
  100% of fossil plants fail catastrophically; the catastrophe is just a bit slower.
- dodobirdlord 6y ago
  Statista claims there are 440 nuclear power plants in operation today, and most of them probably have several reactors. So unless you're using some technical meaning of "commercial" that precludes things like Chinese SOE, I think the claim is just false.
- fastball 6y ago
  No because now we have designs that cannot fail in the same way that 1% did.

Apofis 6y ago

"Ultra Safe" will come with Molten Salt Reactors. Hang tight until then. They can even safely reuse nuclear waste.

p1mrx 6y ago

Illinois EnergyProf recently did a video on USNC's design: https://www.youtube.com/watch?v=7gtog_gOaGQ https://www.youtube.com/watch?v=7gtog_gOaGQ (Though I think he used audio from the wrong microphone; the earlier videos sound much better.)

abalone 6y ago

Serious question: what happens when you take one of these fuel pellets and blow it up and disperse it in the atmosphere / water supply, either accidentally or on purpose? Have they actually designed a solution or is this a fundamental safety risk with all nuclear fuels? All I see addressed is proliferation / reprocessing which is a different thing.

jabl 6y ago
> Serious question: what happens when you take one of these fuel pellets and blow it up and disperse it in the atmosphere / water supply, either accidentally or on purpose? Hmm, nothing? There are already billions of tons of uranium dissolved in seawater (there are actually efforts to try to "mine" uranium from seawater), why would a few grams more matter? As for fission products, humanity has made hundreds of atmospheric nuclear tests, as well as the Chernobyl disaster that spewed lots of fission products into the atmoshpere. Unfortunate and stupid, yes, but not the end of humanity either. And fortunately, fission products decay away relatively quickly. So yes, a few grams of fission products from a spent fuel pellet will not make any impact if it's dispersed enough.
- abalone 6y ago
  Chernobyl caused the near permanent evacuation of a nearby city, and nearly poisoned the water supply for millions. Not a good example if you’re trying to argue a release of fission products is no big deal. I would like to understand exactly if/how this reactor design gets around the risks inherent to explosions of radioactive fuel. If it’s not a problem then why does the marketing take pains to say it will never leave its capsule?
  - jabl 6y ago
    The question of you asked and which I answered was what if we take one fuel pellet and disperse it. I never said Chernobyl wasn't bad (heck, I called it a disaster for a reason!). But that was tons of spent fuel (rather than the few grams being contained in one fuel pellet) being blown out of the reactor building due to the steam explosion, or going up in smoke during the subsequent fires, and even that was far from the end of the world. In this case, I guess marketing takes pains, because one of the main ideas of this fuel type is to make them even safer, even during severe accident scenarios. Is it absolutely fool proof? Of course not; you shouldn't grind up the spent fuel and inhale the dust, for instance.

Animats 6y ago

What about graphite fires?

Gravityloss 6y ago

In the page it isn't explained how it shuts down passively in a loss of coolant event? Since the coolant is not doing moderation, removing it doesn't reduce reactivity at all. You have a 30 bar helium pressure vessel and heat exchangers etc. I wonder how much it's going to leak. Not saying it's bad, just interested in these questions. Some other designs have these issues in focus.

_def 6y ago

"ultra safe" seems a weird marketing term for me. "safe" should be enough, no? Unless they know that it isn't.