NASA Seeks Ideas For a Nuclear Reactor On the Moon (phys.org) 94
An anonymous reader quotes a report from Phys.org: NASA and the nation's top federal nuclear research lab on Friday put out a request for proposals for a fission surface power system. NASA is collaborating with the U.S. Department of Energy's Idaho National Laboratory to establish a sun-independent power source for missions to the moon by the end of the decade. If successful in supporting a sustained human presence on the moon, the next objective would be Mars. NASA says fission surface power could provide sustained, abundant power no matter the environmental conditions on the moon or Mars. The reactor would be built on Earth and then sent to the moon.
Submitted plans for the fission surface power system should include a uranium-fueled reactor core, a system to convert the nuclear power into usable energy, a thermal management system to keep the reactor cool, and a distribution system providing no less than 40 kilowatts of continuous electric power for 10 years in the lunar environment. Some other requirements include that it be capable of turning itself off and on without human help, that it be able to operate from the deck of a lunar lander, and that it can be removed from the lander and run on a mobile system and be transported to a different lunar site for operation. Additionally, when launched from Earth to the moon, it should fit inside a 12-foot (4-meter) diameter cylinder that's 18 feet (6 meters) long. It should not weigh more than 13,200 pounds (6,000 kilograms). The proposal requests are for an initial system design and must be submitted by Feb. 19.
Submitted plans for the fission surface power system should include a uranium-fueled reactor core, a system to convert the nuclear power into usable energy, a thermal management system to keep the reactor cool, and a distribution system providing no less than 40 kilowatts of continuous electric power for 10 years in the lunar environment. Some other requirements include that it be capable of turning itself off and on without human help, that it be able to operate from the deck of a lunar lander, and that it can be removed from the lander and run on a mobile system and be transported to a different lunar site for operation. Additionally, when launched from Earth to the moon, it should fit inside a 12-foot (4-meter) diameter cylinder that's 18 feet (6 meters) long. It should not weigh more than 13,200 pounds (6,000 kilograms). The proposal requests are for an initial system design and must be submitted by Feb. 19.
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His dentist will love you for it.
uh (Score:2)
NASA says fission surface power could provide sustained, abundant power no matter the environmental conditions on the moon or Mars
Environmental conditions on the moon? Are we talking about solar winds or what? At least Mars has weather.
Re:uh (Score:5, Insightful)
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That was my first throught too. I'm going to be very interested in what sorts of thermal management systems they come up with. Water is an excellent medium to transport waste heat through, with air in second place. Lacking both I'm really not sure how they're going to do this. I can't imagine radiative or conductive heat transfer solutions that would fit in a rocket.
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Radiators, under vacuum conditions, are pretty much all about surface area
Well, surface area and thermal conductivity. That's the problem with fold-open radiators, the difficulty of making them also good thermal conductors. You either have to use a fluid to pump heat around through them which is fraught with complexities in this context (like being able to survive holing from micrometeorites) or you have to use mass which makes the folding complicated and also, you know, adds mass.
You'd either want the array in a permanently shadowed area(which puts significant limits on where on the moon you need to go) or actively adjusting angles to make sure that the radiator panels always have their edges rather than their faces to the sun
This is the "easy" part. You don't need to adjust anything. You either put a shade over it or just p
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There should be plenty of water ice on the moon, and coolant doesn't need to be used up over time. They could potentially bore lined heat-exchanger tunnels into the rock as a dumping ground for heat - they make those little utility-tunnel digging robots that would be far more compact than a drilling rig.
Of course there's no particular reason the transfer fluid has to be liquid - Radiant, the nuclear microreactor company founded by ex-SpaceX engineers, is using helium for their 1.2MW reactor coolant since i
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Goodness. I hope those young ex-SpaceX engineers at Radiant know about that, what with their helium-cooled design.
Of course, on the moon, so what? As long as you can direct it outside, what are you going to do - make the radiation-blasted hellscape more radioactive? It should escape into orbit soon enough. Or capture it for fusion - a Farnsworth Fusor makes for a keen fast neutron source... if you have some use for such a thing.
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Like radiator water without the worthless water.
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Reactors have been used in space before where a radiative cooling solution was the only option. Extracting energy requires a temperature difference so the reactor will have to operate at high temperature to get enough efficiency from the radiators, which means either a gas or liquid metal cooled reactor. None of this is new.
Re:uh (Score:5, Informative)
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Kinda pointless building a nuclear reactor on the moon for 10kW though. You could just have some solar panels and a battery for that kind of load. Thermal storage perhaps, you could concentrate sunlight, and you already have a vacuum to store it in.
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I suspect they think of the far side of the moon. Hence why they talk about "sun-independent".
The question is why a nuclear reactor and not a simple RTG like it is done on many space probes and rovers.
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The far side of the moon gets sun as well.
"Dark Side of the Moon" is a misnomer.
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Sure, but for some reason they don't want to store for two weeks of electricity. 40 kw for two weeks is not trivial.
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Neither is building a little reactor on the moon.
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The question is why a nuclear reactor and not a simple RTG like it is done on many space probes and rovers.
Likely because the fuel for RTGs are hard to come by, partly because RTG fuel comes from nuclear fission reactors and we have lower nuclear fission capacity every year. A common fuel in RTGs is plutonium and build a big enough RTG with plutonium and fission is going to happen, so why not just plan on fission to happen? RTGs don't use the same isotope of plutonium as a fission reactor but the Pu-238 in RTGs has a critical mass just like Pu-239 has a critical mass, and they are similar in fast neutron react
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Perhaps you want to read the article, erm, summary.
They want to have a 60kW reactor.
So: you need 60kW? A moon "day" has 14 days sunlight, and 14 days night.
If you need constantly 60kW, you need to have a battery that can store 14*24*60 kWh of energy. That is: 20,200 kWh, or 20 MWh.
To charge a battery with that, and have the 60kW available, you obviously need a 120kW solar panel. 60kW for usage, and 60kW for storage.
So if your reactor is as small as they want it: it is obviously much easier to lift it up the
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FYI, Luna does rotate, once every 28 days so one face is always directed at Earth. As it rotates it has a light/dark cycle just like Earth only the nights are 14 Earth days long.
Only place that gets continuous sunlight are the poles. and even then using solar panels will by difficult as they wound have to be vertical and positioned so they did not shade each other as they tracked the Sun.
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That's what the thermal storage is for.
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Thorium fuel could be locally sourced [wikipedia.org] and processed and does not need to be enriched and has a near 100% burn up that a Uranium does not. Plus the half-life of the fission byproducts is shorter and would not need to be sequestered for as long.
You can jump start a Thorium fueled reactor with a a little U-235 or Pu-239 imported on the first mission or even use a small particle accelerator to provide the neutrons to start the chain reaction. Once a single reactor is going it can provide to initial fissile ma
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reaches a 60 MWd/tU burnup
Oops, that should have been either 60 MWd/kgU or 60 GWd/tU. But of course those who know what I'm talking about can autocorrect for this in their heads anyway...
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> Then there is the issue of storing the spend fuel. We all know what happens when that goes boom.
I remember watching two seasons of documentaries about that back in the late 70s.
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At least someone got the joke, or maybe it was just a nuke fanboy with mod points and no sense of humour.
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large radiator panels will work quite well in a vacuum.
Your thinking in terms of terrestrial cooling where the heat is transferred to another working fluid, water/air and carried away.
In a vacuum the heat would radiate away as infrared radiation as long as the panel is kept shaded from Sunlight. Note that it does not need to be insulated, just shaded, even a mylar sheet could do the job.
Another option would be to use the ground as a heat sink, Some of the extra heat would could be used during the night.
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Re:uh (Score:5, Insightful)
NASA says fission surface power could provide sustained, abundant power no matter the environmental conditions on the moon or Mars
Environmental conditions on the moon? Are we talking about solar winds or what? At least Mars has weather.
Temperature extremes, vacuum, plasma environment.
The environmental conditions on the moon are very different from those of Earth.
Re: uh (Score:2)
Environmental conditions on the moon?
If it goes critical and the containment vessel is breached, the slag could - possibly - melt the cheese.
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Dammit. We'll need to add even more weight to the payload: Fondue sticks.
d'uh Re:uh (Score:4, Informative)
You don't need an atmosphere to have an environment.
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Sinking the waste heat is the first problem I see.
The reactor from NR-1 would almost fit, but I doubt a steam cycle is what they have in mind. Building a steam generator (boiler) for 1/6 g would be an interesting exercise.
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Daylight surface temperature are upwards to 260 degrees Fahrenheit (127 degrees Celsius).
At night it gets to around minus 280 F ( -173 C).
Add to that a hard vacuum, constant bombardment my atomic particles (Alpha particles are Helium atoms stripped of their electrons) and micro meteorite impacts. And lets not forget an incredibly fine dust that will get into and on everything.
So yeah, the conditions on Luna are pretty harsh.
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NASA says fission surface power could provide sustained, abundant power no matter the environmental conditions on the moon or Mars
Environmental conditions on the moon? Are we talking about solar winds or what? At least Mars has weather.
2 weeks long nights, extreme temperatures (-280F, +260F), extremely abrasive dust and additionally Solar activity - make the design quite challenging - hence "environmental condition".
However just going down under the surface would make the temperature much more pleasant and close to the poles will allow for some erected solar panels permanent supply of electricity, yet I would prefer a backup anyway - preferably nuclear.
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We still don't have any decent "room temperatrue" superconductors. And room temperature means "you can cool them with liquid nitrogen". They exist, but they require either high pressure, or they're (so far) impossible to make lengths of.
Once there's something more practical, then you'll hear about it.
P.S.: Amost every idea is talked about LONG before it becomes necessary to deal with the actual mechanics of building it. Consider the O'Neal cylinders. The rough sketch of how to do it dates back to the 1
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Room temperature does not mean "liquid nitrogen", it means room temperature, aka 40F/20C.
We have plenty of "liquid nitrogen" super conductors that work just fine.
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IIUC, they don't work just fine. They either can't conduct much because of collapse. Look at https://ctpcryogenics.com/supe... [ctpcryogenics.com] under the heading "How much current can a superconductor carry?". (It doesn't really answer the question, but it certainly indicates that " they don't work just fine".
There are limited applications for which they work just fine, but it's a limited use case.
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A superconductor transports *indefinite* amounts of current. At least for any terms of human meanings of *indefinite*.
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No, because of problems with magnetic flux causing the superconducting condition to collapse. To prevent that you need to keep them a lot colder than the nominal critical temperature.
Actually, I'm sounding a bit more certain than I really am, but if you've got a link showing that I'm wrong, I'd like to see it.
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To prevent that you need to keep them a lot colder than the nominal critical temperature.
About 1C or 1Kelvin.
Has nothing to do with "room temperature" anyway. Which was the point.
Erm, you want a link about school knowledge?
Here you go: https://en.wikipedia.org/w/ind... [wikipedia.org]
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You keep destroying what I thought were perfectly good arguments about why we didn't have superconducting power lines. Now I'm confused. They're supposed to have these tremendous advantages.
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We have super conducting power lines.
But usually only short range. E.g. The subway in New York City has some.
Why would anyone remove the existing grid and replace it with superconducting power lines? Makes no sense, much too expensive and too cumbersome.
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Re: Oh that's nice (Score:2)
I guess the post is trying to get a rise out keyboard warriors. But good topic to discuss.
I would guess the issue is maintenance, weight, and size. There is dust on the moon, you need to keep the panels clean. Can't just walk out there with a garden hose. You need battery backup when you are in a shadow. Those are heavy! It's probably going to take a few acres to supply the power needs. There are advantages but clearly it's a bigger project than a dense energy source.
As others have posted, I think the rea
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Vastly. But once you get one going, making 5000 of them is not a massive next step. Just time. And that means when you do send humans, you could have gigawatts waiting for them. Or beam some back to the earth.
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Or beam some back to the earth.
Can you explain how this would work? Further, can you explain how to "beam" energy to Earth from the moon in a way that is superior to using nuclear power on Earth?
Obviously (Score:1)
The reactor would be built on Earth and then sent to the moon.
No, really...I'm glad they cleared that up...
Watch Space 1999 (Score:3)
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I saw this show already (Score:2)
Time to get our duct tape space suits ready to go to save the colony.
NASA can smell my B4lls (Score:1)
Thermoelectric (Score:3)
I'm not nuclear expert but I do know that a circulated heated liquid surrounded by thermoelectric materials would be very compact and generate lots of power. However, since both location go from crazy hot in the day to obscenely cold at night (thanks a lot, Sol!), you are going to want to fallback to radiating heat into rock. This probably wont be super heat conductive but it will be able to prevent the reactor from overheating and you know, melting down (generally an undesirable event). However, you should have a way to extract heat before it goes into rock for heating a secondary liquid loop. This could distribute the heat into water which is quite useful many purposes like humans consumption, water purification to recycle human waste, melting mined lunar water, and other things.
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You can just have it obscenely cold all the time by parking in a crater at one of the poles. Does mean it wouldn't be that mobile, but you have to start somewhere.
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Part of "no matter the environmental conditions" means it cannot be location dependent. Don't get me wrong, it's a solid solution to heat disipation but it's too inflexible to meet the requirements.
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The temperature changes that much if they're exposed to sunlight. There are permanently shadowed regions, but they're far from the lunar equator and present additional landing difficulties.
https://moon.nasa.gov/resource... [nasa.gov]
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Part of "no matter the environmental conditions" means it cannot be location dependent. Don't get me wrong, it's a solid solution to heat dissipation but it's too inflexible to meet the requirements.
Compared to solar? (Score:2)
The Moon has ridiculous temperature changes over a for terrain exposed to sunlight. That does leave a lot of engineering issues to resolve for any installation, whether living facilities or a small nuclear plant or solar cells.
Frankly, I'd look to orbital solar mirrors to provide consistent power, with the kind of beamed microwave power to ground stations suggested for solar powwer on Earth.
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In fact, that seems like a 'no brainer'. But you don't need mirrors (which would be for ground-based solar), you need direct solar beamed to a lunar rectenna station.
Because there is no selenostationary orbit possible (the required distance is beyond the Moon's Hill sphere, so the Earth and Sun would pull your satellite off course relatively quickly), you'd need multiple satellites... the number depending on their altitude, but under no circumstances will you get away with two and my uninformed gut instin
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Putting up a network of solar satellites solves various problems for Earth power as well, without the confusion of coping with Earth shadows. It seems a no-brainer to allow the satellites in closer orbit, transmitting in phases to the ground stations.
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The mirrors are concentrators are power collectors for the rectennas in orbit, I'm sorry if that was not clear.
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The rectennas are energy receivers. You use them to convert the microwaves beamed from the satellites into electricity.
You don't put rectennas in orbit, you put solar panels and a microwave beam generator in orbit.
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Thank you for the correction, i used the wrong word. I wanted to be clear that the solar mirrors do require transmitters, they are reflecting to their local tmicrowave ransmitter rather than reflecting the power directly to the ground.
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If ground based solar could be stored reliably and used efficiently, it might still be effective with only ground based equipment. Sending increasingly large masses of nuclear fuel beyond Earth's atmosphere should be a source of concern, even though putting it on a lunar base would seem much safer than leaving it in orbit where it might be more easily serve alternative uses.
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Sending increasingly large masses of nuclear fuel beyond Earth's atmosphere should be a source of concern,
Then mine the fuel on the moon, there's a lot of uranium and thorium on the moon, just like there is a lot on Earth. They'd still have to send up enough fuel to get them started but once the reactors are built and have a starter load of fuel the subsequent fuel can be produced on the moon.
Solar power on the moon to sustain a lengthy manned mission is not practical. The Apollo missions had batteries and RTGs for two men a few uncomfortable hours on the moon. To supply a mission lasting days would take so
Already done (Score:2)
There have been nuclear reactors on the moon. Read this 4 page document: https://www.iaea.org/sites/def... [iaea.org]
The cooling was done by radiation. We are well talking about nuclear reactor and not just radioisotope thermoelectric generators.
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My bad. I posted a link to a RTG, not a nuclear reactor. Well, for the nuclears reactors in space there is SNAP 10A
https://en.wikipedia.org/wiki/... [wikipedia.org]
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We are well talking about nuclear reactor and not just radioisotope thermoelectric generators.
The document in your link is not. It describes a fairly standard RTG.
Thorium SMR is nearly ideal for this (Score:2)
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Process lunar soil to extract Thorium which is *abundant* and fuel it on-site.
Thorium is not abundant. At least not in the sense the word is meaning.
And if you want to process/produce it: your first exercise is to describe a chemical process how that can be done. I guess you will need "heat" and "water" and some "acids" ... good luck Padawan.
Complexity of reactor for 32% gain over RTGs? (Score:2)
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I concur.
Plus the 57kg design was built 20+ years ago. We can do better now, at least in terms a weight. (We didn't even have 3d printing of metals then.) And we can probably do better on the heat watts to electrical watts now.
And if we scale it up we should be able to reduce that further. it looks like they're designed to be stacked. Lunar rock/glass as part of the heat shield means we could produce part of them in situ, after the first completely earth-manufactured batch of them arrived and were got
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Remind me - where, exactly, does your "vastly better plan" source over half a ton of Pu-238 from?
Not only that but how does one keep this much mass of PU-238 from going critical and undergoing fission? Pu-238 is fissile material and if enough is stacked up then it will produce fission, and that fission will produce far more heat than the decay would.
SpaceX submittal (Score:1)
All-in-one autonomous nuclear rocket lander Tesla Starpack StarLink station Amazon buy button for future expansion!
I predict this will fail (Score:2)
Fission needs cooling in all its from. Even an RTG needs cooling. Cooling on the Moon in this range may well be infeasible with current tech, because all you have is heat radiation. If they somebody makes this work, it will be a very interesting solution for sure, but my take is NASA does not want to admit they cannot do it and this is just an attempt at shifting the blame.
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Already solved.
The International Space Station generates about 100kwts of heat during normal operations.
It's radiators handle the load quite well. Getting rid of waste heat in a vacuum is a lot easier than people think and NASA/JPL have been improving the solutions for this issue for decades. Give them some credit for knowing their stuff.
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Have you looked at the size of the ISS compared to what NASA is asking for here? Obviously not.
Why Nuclear? Use Sterling Generator (Score:2)
If you heat a sterling generator with a solar collector (bunch of focused mirrors) and cool through the regolith them you should be able to very easily produce huge amounts of energy. And it's simple, crude, and inexpensive. Solar in space needs to be gallium arsenide, if it is to last.. expensive and limited power generation. Nuclear generates power through heat generation, usually to a steam engine. That's also very expensive...
One could crudely assembly a solar collector using pieces of even a broken
Reactor for the Moon (Score:1)