[HN Gopher] Kaleidos - A portable nuclear microreactor that repl...
___________________________________________________________________
Kaleidos - A portable nuclear microreactor that replaces diesel
generators
Author : sparrish
Score : 85 points
Date : 2025-07-31 19:54 UTC (3 hours ago)
(HTM) web link (radiantnuclear.com)
(TXT) w3m dump (radiantnuclear.com)
| idontwantthis wrote:
| Is it real?
| cactacea wrote:
| From their job listings:
|
| > Additional Requirements
|
| > Must be willing to work extended hours and weekends as
| necessary to accomplish our mission.
|
| So... not yet.
| kwhitefoot wrote:
| I was hoping the FAQ would answer that but, as I expected, I
| was disappointed.
| acidburnNSA wrote:
| Yes it's real. There are a lot of good people who I know
| personally and a lot of funding going into this. They have a
| plan to get fuel and will try to turn the first one on in Idaho
| soonish (like next year)
| wmf wrote:
| It will be tested next year so it's not real yet.
| https://radiantnuclear.com/blog/dome-selection/
| can16358p wrote:
| Sounds too good to be true.
|
| Hope it is true though.
| EA-3167 wrote:
| I have no idea if the testing will go well, if the
| regulatory/political environment will accept it, but as far as
| the company, the tech and the promise of testing?
|
| That is real.
|
| https://www.energy.gov/ne/articles/radiant-completes-study-f...
| trklausss wrote:
| I'm skeptical, not because it can't be achieved, but because it's
| not that practical.
|
| Diesel generators are "great" because diesel doesn't evaporate.
| You can have it there for years, and with good design, it just
| springs up the next day.
|
| This nuclear reactor has to be connected for fleet monitoring if
| you want to operate it. Which excludes it from many real life
| scenarios where diesel generators are used.
|
| Maybe for remote locations where constant power is needed
| (Antarctica and such), but I see their uses being very limited.
| p1mrx wrote:
| If I Google "diesel shelf life", the most common answer is 12
| months. Do you have a better source? Propane probably makes
| more sense for fuel that needs to sit around for years.
|
| Do you know the shelf life of TRISO fuel? I imagine it doesn't
| matter because it would be very expensive to build a reactor
| and not switch it on.
| SR2Z wrote:
| Diesel will degrade with exposure to oxygen, but a diesel
| engine can burn pretty much any flammable liquid that you can
| meter out. It really comes down to the engine itself and if
| it can handle less-than-perfect fuel.
| whatever1 wrote:
| It can even burn its own lubricant oil and die in a
| screaming runaway fashion!
| rob_c wrote:
| I'm sure a nuclear reactor can manage that too if it's a
| competition :p
| whatever1 wrote:
| Not sure it will sound as nice though. In fact I don't
| think I have heard the sound of a runaway nuclear
| reactor. Maybe due to the turbines it can sound exciting?
| lb1lf wrote:
| Anecdotally, I came across a large (for a single user)
| quantity of diesel 9 years ago. (Nothing exotic - a company
| went titsup and I was the only one both bidding for and
| capable of removing the diesel from their premises within an
| acceptable time frame; I got approx 80% off the pump price at
| the time.)
|
| I still run my tractor and Land Cruiser off the stuff; the
| tractor had an outing today. Granted, neither of those
| engines are very particular about the fuel they are given,
| but still...
|
| (Water drained off every few months, also a biocide is added
| to keep the diesel gunk at bay.)
| rich_sasha wrote:
| I don't have any first hand experience with diesel generators,
| but I saw three cases where power was lost and diesel backup
| was switched on. In two of these three cases, the generator
| failed (once didn't start, the other time it ran for 30 mins).
| In both cases it was in scenarios where I'd imagine reasonable
| care and maintenance were applied.
| cyberax wrote:
| > Diesel generators are "great" because diesel doesn't
| evaporate.
|
| LOL, no. I see, you have never worked with large diesels meant
| for backup.
|
| If you just leave diesel fuel alone, then over time (6-9
| months) the residual water separates at the bottom of the tank.
| And then various microbial life springs into action, happily
| living off all of that free energy. While there's some
| dissolved oxygen, it will happily use it to oxidize the fuel.
| But even without oxygen, the bugs will try to live off energy
| produced by polymerization of unsaturated hydrocarbons.
|
| Polymerization == gunk that clogs up your fuel filters.
|
| So you have to periodically clean up diesel fuel by removing
| water and filtering the gunk out. It's called "fuel polishing".
| Large diesels will have fixed systems, for smaller diesels,
| sometimes mobile systems are used like these:
| https://fueltecsystems.com/equipment/pneumatic-systems-2/
| actinium226 wrote:
| > This nuclear reactor has to be connected for fleet monitoring
| if you want to operate it. Which excludes it from many real
| life scenarios where diesel generators are used.
|
| I don't understand this sentence, why does connection to fleet
| monitoring preclude using this microreactor as opposed to a
| diesel generator? Can't you just hook a starlink up to it, and
| program it to shut down in the event of prolonged comms loss?
| linuxguy2 wrote:
| How much does it cost? Would love to buy one with the HOA and run
| our own micro-grid while exporting electricity to the local
| utility.
| unglaublich wrote:
| When HOA gets too powerful.
| salynchnew wrote:
| When the DOE comes after your HOA.
| dylan604 wrote:
| meh, most HOAs can take on the DOD
| GuinansEyebrows wrote:
| This is bringing "My HOA went nuclear on me!" to a whole
| nother level.
| calvinmorrison wrote:
| I have oil clients who would love this. they have to run
| expensive engines left and run on site
| wewtyflakes wrote:
| The poetic irony!
| ggm wrote:
| A flame chart of energy consumption to customer from well-
| head typically shows an astronomical amount consumed at head
| in the gas train. It can be a significant sub of the total
| available energy consumed at the head and in pipeline and
| shipping, to produce the output which can be sold.
|
| Unfortunately much of it can't be sold or shipped off site
| and if it isn't used, will be fugitive gas emissions or
| flared.
|
| Replacing the diesel and other fuels used on-site is good.
| But it's only part of the story. Running the train would
| certainly burn a lot of gas, so replacing that would be good.
|
| (-not a fan of SMR for a variety of reasons, mostly
| political)
| dsadfjasdf wrote:
| Thoughts on using stranded gas as bitcoin miners?
| ggm wrote:
| Inventing reasons to perpetuate fossil fuel extraction is
| counter productive.
| wmf wrote:
| It's already being done.
| KaiserPro wrote:
| From the headline I was assuming it was a tiny 20kw job.
|
| But it being a 1.9mw(thermal) makes sense.
|
| I wonder what the support requirements are, like how do you yeet
| the heat to make it efficient?
|
| Also containing super heated helium seems hard for any length of
| time. I wonder what the operating lifespan is.
| t0mas88 wrote:
| They say it needs to be refueled after 5 years and that it can
| be done 4 times for a total lifespan of 20 years.
| Reason077 wrote:
| 1.9 MWt still seems like a huge amount of energy/heat for
| something that fits on a truck and is supposedly air-cooled
| (they claim no water is required).
|
| Where does all that heat go?! They must have some very
| impressive fans.
| tralarpa wrote:
| Yes, that's crazy. They say up to 1 MW electric which would
| mean (33% efficiency) 2 MW of heat to get rid of with air
| cooling. Later they mention facility heating which sounds
| more realistic, I guess?
| KaiserPro wrote:
| I mean its not that much different from a diesel generator,
| they are around 30% efficient, so they'd also be kicking
| out the same amount of heat?
|
| https://www.generatorsindustrial.com/products/1mw-diesel-
| gen... has a simple radiator.
|
| but then the heat profile is different I suppose, and the
| efficiency doesn't depend on being able to shed heat.
| hagbard_c wrote:
| Meet EMD DDA40X [1], the _most powerful diesel-electric
| locomotive model ever built on a single frame_ incorporating
| two diesel engines with an effective power output of 4920 kW.
| Given the expected losses in the diesel engines (~40-45%
| effective, 60-55% waste mostly in the form of heat) and diesel-
| electric traction system (power generation, traction motors,
| gearing etc, around 80% effective) which gives a total system
| efficiency of around 35%. Assuming most of the waste energy
| ends up as waste heat this ~30m long locomotive (a bit more
| than two 40ft containers) needs to shed around 9 MW of waste
| heat or about 4 MW per 40ft standard container length.
|
| [1] https://en.wikipedia.org/wiki/EMD_DDA40X
| mikewarot wrote:
| At this point, I'll assume that the relevant US regulatory
| agencies are competent, and skip the safety issues, etc.
| What does it cost? How much power can it deliver? So
| what's the equivalent $/KWh?
| jgeada wrote:
| That used to be true, not so sure my trust in our institutions
| is high these days. Seems a few million $ donation to the right
| people can make all regulations just vanish.
| brink wrote:
| > That used to be true
|
| No, that used to be believed to be true. We're just seeing
| the curtain come down.
|
| The food pyramid, the CIA's "war on drugs" in South America,
| the wars with Iraq, Libya.. Just to name a few. Why do we
| pretend like bribery and corruption is this new thing?
| mrtesthah wrote:
| That sounds like an excuse to abide the open corruption
| that's occurring under the right-wing regime in the US
| today.
| brink wrote:
| No it's not. I'm replying to the guy that said "That used
| to be true", because it's obviously not true.
| rob_c wrote:
| And that comment is overly-fastidious.
| acidburnNSA wrote:
| Yeah there's currently a large push to dismantle the Nuclear
| Regulatory Commission and give reactor regulation authorities
| to the states.
| jabl wrote:
| For all the faults of the NRC (real or imaginary), this
| still strikes me as an extremely bad idea.
| dylan604 wrote:
| That's pretty much always been the case. It's just much more
| flagrant and in the open now.
| croes wrote:
| If they go bankrupt who is responsible for the waste?
| gigel82 wrote:
| That's the right question to raise up.
| lawlessone wrote:
| you are :D
|
| yikes from their FAQ:
|
| "The plan is for the small amount of spent fuel (the volume of
| the spent fuel in one reactor is equivalent in size to just two
| Walmart gas grill propane tanks) that comes out of our reactors
| at the end of their duty cycle to only be temporarily stored
| on-site until a federal repository or interim storage solution
| becomes available. "
|
| They don't even have plan while the exist now.
| acidburnNSA wrote:
| Well no one does. The feds cancelled Yucca mountain and so
| there's nowhere for anyone to put nuclear waste. By law it
| belongs to the feds.
|
| So everyone just leaves it in the reactor's parking lot for
| now, in big concrete and steel dry casks.
| dylan604 wrote:
| > equivalent in size to just two Walmart gas grill propane
| tanks
|
| Is this a real measurement in tank sizes? Why not just say
| two 20lb tanks? What if I bought my tank from Home Depot? Are
| they a different size? Do they think using Walmart makes it
| more relatable?
| lawlessone wrote:
| >Is this a real measurement in tank sizes?
|
| That's only 0.393% the size of a football field!
|
| Seriously though, isn't a lump of radioactive material that
| size actually huge?
| daft_pink wrote:
| When can I get a smaller one to power my AirTag?
| philipkglass wrote:
| I know that this is a joke, but reactors cannot scale down that
| far. Unlike an electrical source powered by radioactive decay
| (like certain pacemakers [1]), the minimum mass for a nuclear
| reactor includes several kilograms of material. It's possible
| to shed neutron moderator mass by using high-purity fuel
| operating on fast fission, but these require more fuel to go
| critical so they still have multi-kilogram masses.
|
| [1] "Plutonium powered pacemakers (1974)
| https://www.orau.org/health-physics-museum/collection/miscel...
| dylan604 wrote:
| I want one to take camping
| Havoc wrote:
| That may actually be not that far away:
|
| >first nuclear battery can deliver 100 microwatts of power and
| a voltage of 3V
|
| >plans to produce a battery with 1 watt of power by 2025
|
| https://www.independent.co.uk/tech/nuclear-battery-betavolt-...
| ACV001 wrote:
| A startup where most of the money were spent on that animation on
| the website.
| dylan604 wrote:
| You'd be surprised at what the CAD software can do now in 3D
| renders. You have to design the thing in CAD anyways, so it's
| not like the 3D team had to model it from scratch. You could
| probably just do this with a request on Fivr. These aren't your
| parents 3D prices any more
| SoftTalker wrote:
| Am I right that 1MW of solar generation would only take about a
| football field worth of panels? Of course that doesn't account
| for battery or other storage for nighttime, etc. but seems like
| it would be far cheaper and far less regulatory issues unless you
| really needed that much power generation in a very small
| footprint.
| generalizations wrote:
| "Only"
|
| Looks like a giant part of the value is that it can be shipped
| in, dropped on the ground on site, turned on overnight, and it
| only takes up the footprint of a shipping container.
|
| If you have 24 hrs to find an empty football field within a
| powercable's distance of what you're trying to power, and then
| fill it with solar panels and batteries, you're gonna have a
| bad day.
| nehal3m wrote:
| If you ship in a stack of panels, inverters and cables, sure.
| But maybe you could be a little smarter about it, like a
| container with all the electronics (inverters, batteries,
| management) and a bunch of folded, pre-cabled panels that you
| can pull out across a field. If you bring a couple of those
| covering a field in a few hours shouldn't be that hard and
| could be ready for use instantly provided the batteries are
| charged at delivery.
| generalizations wrote:
| You also have to make sure there's an empty football field
| onsite. That's a much harder ask than dropping a shipping
| container in a couple of parking spots.
| asdfman123 wrote:
| It requires space, setup time, and then there's the
| intermittency issues. You'd need enough batteries to store,
| what, 12 MWh? 20? More if you're accounting for cloudy days?
|
| People just want a compact solution to generate power, not a
| whole separate project.
| jonplackett wrote:
| Wouldn't the point be that it works at night too?
| esseph wrote:
| You're not accounting for location at all.
|
| Nor is that generating electricity at night.
|
| Plus battery storage.
|
| And it's closer to 4-6x football fields if you did it in say,
| San Francisco. 4-5x football fields in Kansas City. 6-8x
| football fields in Chicago. Again, plus battery storage.
| hinkley wrote:
| How many power problems would be covered by making a battery
| the size of this device
| esseph wrote:
| zero
| actinium226 wrote:
| Depends entirely on how you charge the battery.
| daemonologist wrote:
| It depends on where you're at, but for a sunny place yes;
| somewhere like London a panel can harvest ~100 W/m^2 (0.5 MW
| for a football field with 100% panel coverage) averaged over
| the whole year, while in Arizona it's more like 230 W/m^2 (1.2
| MW for a football field). NREL has some great insolation maps
| here: https://www.nrel.gov/gis/solar-resource-maps
|
| For a _permanent_ installation I would agree that solar would
| usually make more sense, but the mini reactor might be better
| in scenarios where it 's replacing a diesel generator -
| emergencies, temporary events, confined spaces, etc.
| jauntywundrkind wrote:
| Everything I've heard is that micro-reactors produce far worse
| waste situations than larger scale options.
|
| I think there's a huge opportunity for nuclear power in the world
| today.
|
| But: all these micro-reactor strike me as disastrously bad idea,
| that's all too likely to offload incredibly complex nasty gross
| problem to the future. Costs that alas will likely be handled as
| network externalities, as drains and damage against humanity and
| people and government, that the creators and purchasers of these
| device will skate through with comparatively little injury.
| DoctorOetker wrote:
| From a humanistic species survival perspective, we should
| conserve nuclear energy for interstellar travel.
| 9dev wrote:
| Interstellar travel to... where? It's like saving your money
| for an immortality treatment that'll eventually hit the
| market. Well yes it might, someday in the far far future.
| Practically speaking, this money should better be invested in
| your health now instead, aka. preservation of the only
| spaceship we have right now--Earth.
| generalizations wrote:
| Counterpoint: we've been powering ships with microreactors for
| decades.
| acidburnNSA wrote:
| Most nuclear-powered ships have reactor powers in the 40-300
| MWt range, a bit beyond the typical 10 MW limit for
| 'microreactors'
| evan_ wrote:
| This was new to me so I looked it up- "MWt" means Megawatts
| Thermal - e.g. the heat output of a reactor, which would be
| turned into a smaller value of MWe- Megawatts Electric
| corranh wrote:
| Hopefully this needs a smaller crew to operate than a Nimitz-
| class aircraft carrier.
| dylan604 wrote:
| The nukes on a carrier are a much smaller team within the
| carrier's full crew though. So if you extracted the guys
| that glow in the dark, it might be more inline
| zer00eyz wrote:
| We sure have.
|
| And it is a money pit.
|
| And then you have things like this:
| https://www.navytimes.com/news/your-navy/2019/01/10/two-
| sail...
|
| It's proof that you can build a robust and safe reactor, but
| like all things under triple constraints it will not be
| cheap.
| jauntywundrkind wrote:
| And we're starting to have to decomission them! At absurd
| costs!
|
| We just awarded $0.5B to decommission the USS Enterprise (CVN
| 65), the first nuclear aircraft carrier. More will follow!
| https://theaviationist.com/2025/06/03/uss-enterprise-
| dismant...
|
| The DoE has been helping to decomission Los Angeles class
| attack subs for a while now. Here's a piece on that:
| https://www.defense.gov/News/Feature-
| Stories/Story/Article/4...
|
| It require enormous care & effort. It's fantastically costly.
| Do I think it was worth it? For a mission like this: I think
| yes. For the good of a nation. And a Nation that hopes to
| still be around to take care of the problem, the complex
| decomissioning decades latter. But I have so little faith
| that private interests will endure and bear their own
| responsibility for this awesome but deeply corrupting
| irradiating force.
| Peteragain wrote:
| Yep. And the Russians have had pluggable nuclear power for
| years now.. on barges: wikipedia.org/wiki/Akademik_Lomonosov
| Decommissioning no doubt will consist of scuttling them over
| a trench. Definitely going to wake the Kraken.
| yongjik wrote:
| Considering that fossil fuels "solve" the problem by literally
| dumping its waste onto the atmosphere, endangering the global
| ecosystem, and we're still merrily using them...
|
| I think it's a bit melodramatic to say microreactors offload
| nasty environmental problem to the future. Also, their
| environmental problem is literally at the scale of "Drop them
| in an abandoned mine somewhere, where they cause zero harm to
| the world, and we will have a few centuries to figure it out."
| legulere wrote:
| Recapturing the CO2 from the environment of fossil fuels is
| almost impossible is almost impossible. Recapturing
| radionuclides is much much more difficult. Also the duration
| in which radionuclides are a problem has to be taken into
| consideration, making even babysitting nuclear waste
| extremely expensive.
| acidburnNSA wrote:
| Meh it's a little bit worse, because smaller reactors burn a
| smaller fraction of their fuel and therefore make more volume
| of high level waste per kWh generated.
|
| But it's not THAT much worse. Nuclear waste is already
| ridiculously small in volume per kWh vs. any other fuel-burning
| energy technology. Right now all of the waste we've accumulated
| from making 20% of the country's electricity for decades fits
| on a football field 3 meters high (that's pellets only, if you
| include individual dry casks it's 135 meters). So if we make
| lots of small reactors that are a bit less fuel efficient we
| might need 2 big football fields deep underground rather than
| 1. Compared to all the particulate and CO2 emissions other
| sources make I'm just not that worried about it. Recall that
| fossil kills ~6 million per year from particulate emissions
| alone. Commercial nuclear waste has never hurt anyone, and is
| unlikely to do so in the future.
| ChuckMcM wrote:
| Looks basically like the TRIGA reactor design (without the water
| shielding). Seems to have similar challenges with rapid load
| changes. At one time I thought NASA was looking at something like
| this tied together with a battery pack that would allow for rapid
| changes in dynamic load without a lot of stress on powering
| up/down the reactor. And now I can't find it. Sigh.
|
| If you're a billionaire building your bunker this would be the
| ultimate off-grid power source :-).
| acidburnNSA wrote:
| It's a lot different from a TRIGA. It doesn't have hydrogen in
| the fuel and it uses high temperature/high pressure helium gas
| as the coolant (vs. water in a TRIGA).
|
| We did run a nuclear reactor in space once that did use TRIGA
| fuel. It was called SNAP-10A. More recently, the Kilopower test
| ran a reactor on land but intended for space with a U-Mo
| metallic fuel.
| acidburnNSA wrote:
| This is a passionate team working on a very hard problem. They
| have guts and skills. I've always loved microreactors for fringe
| remote power where people are willing to pay 20x more than normal
| diesel generator prices. Like Antarctica, remote bases, the moon
| etc.
|
| Trying to make microreactors cheap is super hard. We've obviously
| tried it many times, the most relevant being the truck-mounted
| military microreactor ML-1 (the only closed-cycle direct gas
| turbine reactor ever operated)
| https://en.wikipedia.org/wiki/ML-1.
|
| Shielding is hard. Even a small reactor this size needs like 8
| ft. of high density concrete on all sides, or equivalent, plus
| 4-6" of a heavy metal like tungsten to take down the gammas. You
| can't just put it underground because the neutrons activate the
| dirt. Driving it off afterwards is borderline impossible because
| you generally have to put the spent fuel in robust canisters that
| can handle collisions, rollovers, and RPG attacks.
|
| But the hardest part is fuel cost. This reactor uses medium-
| enriched ('HALEU') fuel, which is super expensive, and then it
| packages it into TRISO form, which is about 100x more expensive
| to fabricate than regular UO2 fuel. On the plus side, it's super
| robust and can minimize the need for other safety systems. Those
| prices could both go down, conceivably, but the fab process is
| pretty intricate, and it's hard to bring down enrichment costs.
| In my analysis, the fuel cost alone nearly makes this kind of
| reactor uncompetitive with a diesel generator in almost all
| applications. So even if the reactor is free (because you build
| it on an assembly line?), you're still out of luck.
|
| Then there's thermal strain. When you're a small reactor you have
| big gradients. This bends things. Neutrons make it worse. Then
| you have a tiny box with electronics in it getting absolutely
| hammered by neutron dose. That does bad things too.
|
| I hope they can find a way to bring fuel costs way down. I really
| like the people at this company, and I really like nuclear power
| and want to see it used in many new applications. I just don't
| quite see the path yet.
| no_wizard wrote:
| Wonder if much of the world didn't turn away from nuclear power
| they way they did since the 1960s, if we wouldn't have solved
| alot of problems like these already given research was stagnant
| (relative to other research in power generation) for a very
| very long time.
| acidburnNSA wrote:
| It'd be a much different field if we had kept it up. I spend
| a lot of time in nuclear archival material, and facilities
| like CANEL in Middletown CT absolutely blow my mind. They had
| hundreds of people working on crazy reactor technologies.
| They were flowing white-hot lithium metal at 100 mph. But
| yeah we gave all that up. My friend wrote a pretty good
| article about this not long ago https://www.ans.org/news/2025
| -05-08/article-6961/hightempera...
| binary132 wrote:
| In order for this to happen, making websites and mobile
| apps is going to have to get a lot less lucrative.
| ortusdux wrote:
| > I hope they can find a way to bring fuel costs way down.
|
| I've spoke with some researchers and investors working on
| seawater uranium extraction and left quite optimistic.
| philipkglass wrote:
| Extracting uranium from seawater gives you natural uranium,
| which needs to be enriched for use in most power reactors.
| The reactor under discussion here needs higher uranium
| enrichment and more expensive fuel fabrication operations
| than common power reactors. Developing uranium extraction
| from seawater is a good long-term insurance plan for uranium
| availability, but it's not going to help this reactor get its
| fuel costs down.
| cyberax wrote:
| > On the plus side, it's super robust and can minimize the need
| for other safety systems.
|
| Can it survive 20 kilos of TNT planted by a terrorist?
| acidburnNSA wrote:
| If they radiation shield it properly, I'd like to think so.
| That won't do anything to 8 ft of concrete plus 4" of
| tungsten.
|
| Plus the fuel form holds in a lot of the fission products
| even when scattered around. It may overheat and release
| volatile fission products but I don't think it would be a
| widespread disaster no matter what.
| AnthonyMouse wrote:
| I don't really get the "make it small enough to fit on a truck"
| thing. The main impediment for nuclear is cost, and then being
| able to build reactors on an assembly line would be a
| significant advantage. But how much of that advantage is
| retained if the product comes on more than one truck and the
| thing that comes is the reactor, the fuel and the turbines
| whereas the concrete gets poured on-site? It seems like that
| should get you nearly all of the cost savings from mass
| production but then you get a full-sized reactor that can power
| a city instead of something that can only replace a diesel
| generator.
| rob_c wrote:
| Fantastic if true.
|
| I'm sure there's a few catches or weed already have them back
| ordered globally but frankly anything that normalises using these
| self heating rocks to boil water gets my vote :)
| Peteragain wrote:
| Looks aspirational to me. 1Mw electricity at 30-100% efficiency
| (100??) and 1.9 Mw heat via air in the volume of a shipping
| container? That's moving a lot of air. And I'd want fail safe,
| passive control "rods" (what happens if the helium leaks out and
| the heat isn't being removed) before I'd sleep easy with one in
| my back yard.
| gregbot wrote:
| This type of fuel basically cant melt so with no helium it
| would just heat up and natural convection would cool it.
| ranie93 wrote:
| Could this be associated to a supposed recent State Department
| approval?
|
| "I just approved a program to deploy small modular nuclear
| reactors built in the United States to an allied country to help
| with their sort of energy infrastructure."
|
| "Which allied country would that be?"
|
| "I can't tell you. It's not public yet."
|
| From Interesting Times with Ross Douthat: The DOGE Alum Asking if
| Foreign Aid Is America's Problem, Jul 31, 2025
| gmueckl wrote:
| I'm not filled with optimism about this concept. Let's work
| backwards from crash safety (say a reactor on a truck getting
| t-boned by a freight train). The radioactive material needs to be
| held in an armored containment to avoid release. That would have
| to be roughly comparable to CASTOR containers in terms of its
| resilience. But these containers have limited capability of
| passive thermal energy dissipation (Google finds models that
| handle 10kW to 45kW thermal power generated in the interior).
| This would be approximately the ceiling for the direct thermal
| power output that is still reduced by limited efficiency of heat-
| to-power conversion.
|
| This is admittedly napkin math, but it should be good enough to
| set expectations.
| jillesvangurp wrote:
| You are thinking accidents. I think we need to be thinking
| deliberate attempts to compromise these things and all the
| security measures needed to mitigate against that. And most
| importantly, the cost associated with that. Which comes on top
| of already significant cost.
|
| The naive notion of we'll just ship these all over the place by
| the thousands and it's going to be fine is not going to
| withstand a lot of critical thinking very long.
| gmueckl wrote:
| I was indeed not thinking about deliberate attacks. But that
| doesn't change the result much as I assume that the CASTOR
| containers that I used as reference are designed to withstand
| all of these worst case scenarios.
| conorcleary wrote:
| Unfortunately, this chain of messages underscores the
| importance of keeping humans in check with eachother, and
| the machine.
| altcognito wrote:
| Hundreds of thousands if we're talking about meeting growing
| demand. Which doesn't give me a lot of hope for solar either
| though.
| metadat wrote:
| 1. Can I have one in my driveway?
|
| 2. Why only refuelable 4 times?
|
| 3. Is it really safe to fly around with in an airplane? Can major
| airlines help distribute these via standard flight routes to
| reduce cost?
|
| 4. What happens when home base monitoring detects a problem with
| the reactor? (And why isn't this covered in the slides to put the
| audience at ease?)
| MadnessASAP wrote:
| > 3. Is it really safe to fly around with in an airplane? Can
| major airlines help distribute these via standard flight routes
| to reduce cost?
|
| These are too big for your standard air freight network or
| aircraft (that is, it's significantly larger then any typical
| ULD [Unit Load Device, shipping containers for airplanes]).
|
| So it'll definitely be a charter to get one delivered. Weights
| going to be the big determinant in cost, dimensionally it looks
| like you could get it into anything bigger then a C-130. I
| doubt you'll be within the C-130s weight limits though.
| cyberax wrote:
| The USSR did it first! No, really. There was a mobile power
| plant: Pamir-630D ( https://imgur.com/a/rCexHAA ).
|
| It was even deployed to provide power to a remote Arctic outpost.
| It had to use an exotic coolant (basically, a rocket oxidizer) to
| make it work, and it had to be placed far away from anything
| else. The shielding was not enough to bring down the gamma
| radiation to a safe level when the reactor was active.
| actinium226 wrote:
| Not sure about who was first but McMurdo station in Antarctica
| was for a time powered by a nuclear reactor almost identical in
| power to the one being discussed here:
| http://large.stanford.edu/courses/2014/ph241/reid2/
| 1shooner wrote:
| >We have fully modeled worst-case - as well as lesser-case -
| scenarios for an accident or leak. The analysis has shown zero
| impact experienced by the public.
|
| Well that's a relief.
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