How small can you make a nuclear reactor?

[@nealkonneker6084]

I am disappointed a small nuclear reactor hasn't been built at the Antartica research station. It would eliminate all the massive amounts of fossil fuels that must be transported there now. Nuclear would be especially useful there since the "waste heat" would actually be as valuable as the electricity generated because of the cold climate.

[@mikebar42]

But it uses water... That might be a problem eventually.

[@perryallan3524]

The US Navy did operate a nuclear reactor and power plant in Antartica for decades. At end of life it was extraordinarily expensive to remove and they shipped something like 10,000 tons of radioactive contaminated materials back to the USA for disposal. Anyway, it was felt that diesel generators and combustion turbines now are much cheaper than a small nuclear reactor.

[@matthewmulcahy4402]

Why nuclear reactors? Why not solid state nuclear power cells? For example, Strontium 90 (of which we have plenty) produces no gamma radiation. It can be dissolved in glass or carborundum and power anything. It is easily and safely discarded. Check out “The Half Life of a Nuclear Battery” by Philip Talbert.

[@perryallan3524]

@@matthewmulcahy4402 Strontium 90 (and a number of other radioactive isotopes) can only be directly used in a radioisotope thermoelectric generator (RTG). RTGs work from the decay heat and do not generate much power. Fine for some satellites or for some low power needed remote station. But, not at all suitable for powering houses, businesses, or labs unless you have a very large quantity of them. A nuclear reactor that splits elements by fission produces something like 1 Million times the energy for the same size. Now you have to add the various power conversion technology (boilers, steam turbines, etc) but it is still vastly more compact than RTGs.

[@SMGJohn]

Soviets developed nuclear batteries for exactly this reason, the reasoning being that a nuclear battery was easier to ship in and out, provided enough power for an entire decade meaning very low maintenance was needed, they were extremely common in Siberia and other remote locations, Soviet arctic also had a bunch of these, thankfully they removed them just before the collapse since after 1991, all these batteries in Siberia are just rusting away, alongside large nuclear plants that were abandoned by Yeltsin.

[@HarryWHill-GA]

The Soviets used to build VERY small, unshielded, unattended nuclear reactors. They used them to power remote navigation aids. As I understand it there are still about two dozen or so that haven't been cleaned up. Unshielded reactors are also used to power unmanned space craft.

[@SMGJohn]

Those were nuclear batteries, and they were shielded, stop spreading lies, you could easily just Googled that would taken you less than a minute. They are a safety issue today because after fall of USSR, the entire bureau that was designated in USSR to maintain and place these nuclear batteries literally dissolved by Yeltsin because "it was too expensive" and it was also too expensive to clean them up, so they are basically just rusting away in the nature and 30 years exposed to the environment has started to crack the shielding on many of them meaning they become dangerous. But seeing the state the Russian country side is in today, well those batteries probably wont be cleared up any time soon. Again, 1 minute research, would yielded you this, instead you spread false information on the internet for what I assume is pure cold war mentality.

[@wishusknight3009]

I don't know if they can be called reactors exactly. They just had those plates that could generate electricity on heat alone, and their power output was something like 15 watts. As far as I understand they were nowhere near criticality.

[@HarryWHill-GA]

@@wishusknight3009 Technically they were Radioisotope Thermoelectric Generators (RTGs). They used radioactive strontium-90 as a fuel source to generate power using the Seebeck effect. NASA used Plutonium-238 on space probes. I would argue that any device which generates electrical power by means of radioactive heating qualifies as a reactor.

[@wishusknight3009]

@@HarryWHill-GA Fair point.

[@perryallan3524]

The largest Soviet RTG only generated 180 Watts of power. The vast majority of them were between 10 and 80 Watts. The largest space probe RTG that I have identified was only 300 Watts - and were built by the USA.

[@stickynorth]

5 MWe eVinci is the smallest reactor design currently under way and it's designed to fit in a shipping container... And to be used in the arctic...

[@icomsltd]

NERVA had a reactor about the size of a brewing tank.

[@camresearch5120]

SNAP. It depends if you are bothered with a Bio shield or not.

[@EvidentlyChemistry]

Yes, and the Clementine core was about 6" wide IIRC. Including heat removal etc. A very small bowling ball indeed.

[@eprofessio]

I think of the small Soviet nuclear batteries used in remote locations when I see this.

[@benjaminshropshire2900]

IIRC those are non-critical devices and thus don't generate very much power.

[@eprofessio]

@@benjaminshropshire2900 most peltier devices don’t make much power. It’s still neat how they work.

[@benjaminshropshire2900]

That too, but I was referring to the amount of thermal power available to be converted for other use. IIRC that conversion to electric power is around 10% so the output power for a lot of RTGs is about the same as an old style light bulb.

[@spvillano]

@@benjaminshropshire2900 worked great for old remote Soviet arctic lighthouses, worked great for space probes. Gave us some cool information with Pioneer (see the Pioneer Anomaly) being literally accelerated by thermal photon leakage. I think it was an Italian researcher that resolved that mystery.

[@zapfanzapfan]

The Soviets made small reactors to power radar satellites, one reentered over Canada...

[@spvillano]

And a few more still in orbit. Two launch/deployment failures, one landing in Canada, the other in the Pacific, the rest in orbit for the next 300 years, then they'll reenter. The US has one in orbit, it'll reenter in around 4000 years and all are now spewing space debris all over LEO, ranging from metallic reactor coolant through spacecraft components.

[@saturnslastring]

I seem to recall a place had a tabletop licensed reactor rated for 4 watts of power that had a reportable occurrence to the NRC for exceeding their max power level and getting up to 6 watts 😂

[@donnovicki9771]

The radioactive boy scout was working on it, in his mom's back yard.

[@benjaminshropshire2900]

TRIGA reactor are safe enough to be run by undergrads and the core is only about 6ft across. That said they basically don't have a containment structure so "walk away safe" is only for as long as it takes to start leaking.

[@lv4077]

CO2 emissions are totally inconsequential.Nuclear power should be implemented however to help extend “fossil fuel “.i hate that ridiculous term,reserves much further into the future

[@branchcovidian2001]

Radioactive Boy Scout could make them shoebox size.

[@KevinBalch-dt8ot]

I wonder how he would have turned out if he had an adult mentor in his life.

[@zapfanzapfan]

A shed is not a good containment building 🙂

[@darknase]

50 MW to 250 MW LFTR with a Brayton Cycle turbine (Supercritical CO2 instead of water and thus steam), which itself fits into the size of VW Golf fits into 40ft shipping container. And just as his PELE it's all wishful thinking just that we know that MSR/LFTR actually work.

[@KevinBalch-dt8ot]

It doesn’t just have to work. It has to produce power at a competitive price and be able to be built on a predictable schedule. Until a prototype is built, we won’t know.

[@deletesoon70]

Another technical hurdle left somehow uncleared, kicked down the road for years. My hackles tell me we could have had our energy solutions solved decades ago, but for the utility of crisis.

[@terry_willis]

How big is the nuc reactor in a submarine?

[@johnking6252]

Yeah, but we got the bomb ! Jaws..1975 ? Hahahaha hahahaha.

[@jimtrowbridge3845]

The most insane design I've ever heard of is using Uranium hexafluoride as both the fuel and the working fluid. Heats up in a spherical reactor then runs thru a turbine, cooler, compressor, then back to the reactor. Won't ever be built, of course.

[@KevinBalch-dt8ot]

That would be a nightmare operationally. Any leaks would be highly radioactive as well as chemically toxic making repairs and maintenance difficult. Probably murder on blades in turbine and compressors.

[@spvillano]

@@KevinBalch-dt8ot from what I recall from the chemistry side, they use passivation with fluorine as a pretreatment, lowering erosion significantly. There was similar actually used in the NERVA prototype, the other was a proposed and never built nuclear spacecraft engine.

[@ThananLebb-yd4lh]

Let's just dump the radioactive stuff everywhere

[@myth-termoth1621]

Does anyone know why the PIC and sound are way out of synch ?

[@ghost307]

At least a car based on nuclear power would solve both the range and the recharging time issues while reducing emissions and saving the planet.😂

[@hellstromcarbunkle8857]

Well there's always the car crash poisons everything for 100 miles problem.

[@colettes9758]

EXACTLY!!​@@hellstromcarbunkle8857

[@Jeff-iz9hn]

A nucler powered car was feasible back in the 1950s. I think there have been advancements since then.

[@KevinBalch-dt8ot]

It was conceived of but that’s as far as it got other than the Batmobile. I know AEC regulations were not as strict as today but how did Bruce Wayne get away with having his own nuclear reactor?

[@malcolmwhite6588]

@@KevinBalch-dt8ot easy - they didn’t know Bruce Wayne was Batman and though the authorities knew Batman had the reactor, they didn’t know where the Batcave was so between that blind and double blind, the authorities never were able to find it!👍😂

[@FernandoWINSANTO]

How many online videos can you make about nuclear reactors? say in 24 hours

[@robertbhayes5039]

How long do the videos have to be?

[@kishfoo]

Yup. The north. Preferly Greenland. All the cold air needed to cool all the mini nuclear engines will create a new country. Try it in a metropolis, and you get stagnate air 50 degrees celcius+. Solar panels in hotter areas will help those hotter areas stay cooler by allowing for better thermal release at night. Now wind. If only storms take certain paths all the time. Don't want to be in a country down wind from a wind turbine farm. I would not want to love on the west coast of any country with wind farms all along its east coast, ot down river from a hydro power dam. Sadly, there is no free energy. It's always stolen from something or somewhere else. Except maybe fusion...if it works.

[@RichardLucas]

The hard reality is that you're not going to get a family-sized or individual use reactor and it has nothing to do with the limits of technology. If you give people unlimited power, you'll quickly see that _some_ people can leverage that power to make their own fertilizer, power their robots, and generally survive or even thrive independently of society. That, in itself, _is_ the problem. Things are not what they seem.

[@spvillano]

You'll not get a family-sized reactor due to cost, uranium isn't exactly cheap and you need at least HEU or even weapons grade for small reactors. There are commercial village sized reactors available right now, but nobody can afford one. Direct burial, lead cooled.

[@RichardLucas]

@@spvillano I stand corrected, but the point regarding the underlying, non-technical issue remains. Desalination is another example of technology that could potentially become less prohibitively expensive with metamaterials, say, but it would remain unattractive to people who would use water scarcity to drive other agendas.

[@spvillano]

@@RichardLucas well, we can't get rid of scarcity, that's commie talk or something equally idiotic. Or at least not enriching Richie Rich and Daddy Warbucks. As for desalination, depends upon the methods employed and energy source. For a fair amount of the world, there's enough solar energy available to generate energy and desalinate seawater for multiple countries based off of only one or two small powerplant sized units and that's with current technologies of things like standard thermal collectors and anhydrous ammonia. Go with the metas for less energy wealthy regions, where the increased efficiency is needed. Oh wait, we have trouble even feeding uncontaminated water to US inner cities and we're the best in the world at mediocrity. I mean everything. Odd how no other industrialized nation has these problems or our third world death rates from preventable diseases.

[@R.E.A.L.I.T.Y]

Never small enough to be safe, cheap or clean enough for mass generation but ok for spacecraft & subs

[@discombubulate2256]

yeah it's not the reactor so much, just the packaging. regulators will want it dead set impregnable, and always trackable where ever it goes.

[@zevfarkas5120]

How about the small nuclear generators that are used in things like space probes? Aren't they the power sources for the Voyagers?

[@robertbhayes5039]

Those are not nuclear reactors, but rather radioisotopic thermoelectric generators

[@zevfarkas5120]

@@robertbhayes5039 The difference being?

[@perryallan3524]

@@zevfarkas5120 The heat source is from natural radioactive decay, not from the intentional fission of atomic nuclei at rates millions of time faster than natural decay - and producing daughter products that natural decay does not produce..

[@hvnterblack]

Small nuclear devices has big potential as orphan sources. Every city with own small NPP? In theory sounds like generation of heat and electricity close to customers sounds great, but it is in ideal world. In ideal world comunism work. So why it doesn't in reality? Reason is humans. We are lazy, we cut corners, dissobey safety procedures for make work easier and faster. Big reactors have much higher potential for catastrophe, but chances are almost none. Small reactors have less dreadfull possibilities when failure, but there is need for much more of them, so it is rising chances of accidents.

[@robertbhayes5039]

On the chance that you might be interested to find out how recent research has shown anti nuclear narratives based on claims of excessive radiological risk are effectively founded on social myths, here is the paper: Hayes, R.B. Cleaner Energy Systems Vol 2, July 2022, 100009 Nuclear energy myths versus facts support its expanded use - a review doi.org/10.1016/j.cles.2022.100009 www.sciencedirect.com/science/article/pii/S2772783122000085

[@LeCharles07]

/wave Hi FBI person. I hope you have a great day.

[@BattShytKuhraezy]

SHARP GUY

[@mikespangler98]

NR-1 en.wikipedia.org/wiki/American_submarine_NR-1 Also if you were near the poles you could take advantage of the cold with a pentane or butane bottoming cycle so the heat sink temperature is not limited by freezing the water in the condenser tubes.

[@doogleticker5183]

The USA built a reactor in the ice sheets of Greenland decades ago. It was comparatively small.