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"The UKSA will now provide £2.9 million (around $3.52 million) of funding for the project."

A nuclear reactor on the moon?

I don't get it.

Meta spent north of $30 Billions to build a "metaverse" that I would not even consider to be alpha-level quality, and some people at Rolls-Royce think they can build a nuclear reactor for how much?

They’re just adding money to the pot, from my read of it.
FAANG spending isn’t the norm, the total program cost of the Mars 2020 rover was $2.7 billion.

Meta spent $30 billion on something that looks like SecondLife on the Wii…

But also this ain’t the total cost just how much money the UK government is funding the project for right now.

It’s really mind boggling how much money Meta spent on this thing.
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Any time someone complains about the government buying $600 toilet seats as an example of how the government wastes money, just point them to the MetaVerse.
$600 for a virtual toilet seat.
Did they seriously spend that much money on it??? How???
I don’t know if that’s how much they spent on it or was that how much they “spent” on it.

But the cumulative cost of Reality Labs was apparently indeed $36B over 3 years.

1. Meta had to have spent vastly less than $30 billion on their "metaverse". That's ~80,000 person-years of senior SWEs.

2. Literally half the companies who have video games as their core competency would have been able to build way more for way less.

Imagine if we put effort into humanities and science instead of trying to get people to buy stuff they don’t need.
They’re already building small modular nuclear reactors for power stations and submarines. This is just for the work to make it work in a lunar environment
dumb question maybe, but with out an atmosphere, isn't there virtually unlimited solar potential on the moon? why is a nuclear reactor needed?
Because you have a cycle of ~14 days of darkness and light on the moon so solar will need a backup.

Batteries are an option but 14 days worth of storage for a lunar base is probably asking a bit too much.

Also nuclear provides another benefit on the moon - heat which you’ll definitely need during those 14 days of darkness.

Another benefit might be protection from asteroids and meteorites if built underground.
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In addition to what others have said, in the places where the water is and the energy is needed, there is no sun. So you need to first go to a place where there is sun, then beam energy into a crator.
Is there somewhere someone’s done the numbers on bootstrapping industry off world? Like what would make most sense very first, etc. It strikes me that at some point it makes a lot more sense to build the stuff to build more stuff out there.
NASA did a study in the 1980's. For something more recent, I suggest checking out Dr. Casey Handmer.

https://ntrs.nasa.gov/api/citations/19830007081/downloads/19...

Wow awesome thank you!
It's a super-specific niche that I'm very interested in but sadly has very little activity, so I'm happy to spread the word. ISRU "in-situ resource utilization" gets a bit more press more and then.

Isaac Arthur also has some good episodes (video/podcasts) on the subject of bootstrapping off-Earth industries like on the Moon or asteroids or Mars.

There's a problem with nuclear power on the Moon. How do you get rid of the heat? Here on Earth, we just use water, of which we have plenty. But on Moon water is extremely scarce. It would make the sci-fi novel Dune look like an oasis. When we'll have some type of an economy on the Moon, it's very likely that water will be more expensive than gold. One thing is absolutely certain: we will not be able to afford to vaporize water and let the steam vent. So, any nuclear reactor on the Moon will need to have some complex array of pipes where steam is circulated through some radiators, then condensed and recirculated. Or, who knows, maybe we'll do this cooling with liquid metals. Among the more abundant metals on the Moon, tin could be a good candidate; there was an experimental reactor at the Oak Ridge National Lab in the 60's that used liquid tin as a coolant.
Heat will be an asset, not a problem: the Moon sub-surface temperature is around -20C ([1]), which means there's an easy way to dissipate power. And if we have any humans living on the moon, that heat will very much be appreciated around all livable areas.

https://space.stackexchange.com/questions/19906/constant-lun...

Interesting!l, havent ever thought about that!

What is the heat conductivity though ? If it is low, you might have to sink too many heat transfer channels, not to mention with possibly ending up with a hot "bubble" that would no longer provide a temperature gradient.

Under the layer of regolith, Moon crust is mostly basalt ([1]), which has about 1.6 W/mK thermal conductivity ([2]). Not great, not terrible.

We all know how cold it is to stand on a stone floor - unlike wood or plastics, it keeps sucking that heat off.

1. https://en.wikipedia.org/wiki/Internal_structure_of_the_Moon

2. https://en.wikipedia.org/wiki/List_of_thermal_conductivities

Nice Chernobyl reference!
Your forgetting about radiation. You don't need to conduct it all away, there are 3 modes of heat transfer, conduction, convection and radiation. In this case it's the radiation they'd rely on.
Sunlit surface of the Moon can reach 127 C. Don't know what type of reactor they choose, but it obviously won't work for boiling type of reactors.

UPDATE: I forgot about not-water coolants. Molten salt or liquid metal reactors can work at 500 C, so would radiate anyway, right.

Radiation doesn't need a temperature gradient anyway
I don't know if that will cool the reactor enough to prevent a meltdown.
Cooling a gigawatt-class reactor like that? - not a chance

A 10kW reactor - easily; a very limited amount of engineering to design a heat distribution system will be required, but 10kW is also not enough for anything useful.

I suppose the future of Moon energy will be in megawatt-class reactors, which are still possible to cool like that, but provide enough heat+energy to be useful for colonies.

Other liquid coolants could be used and recirculated.
I feel like it would be easier to build underwater cities via a network of watertight buildings than colonize the moon. At least with underwater cities we can essentially have flying cars (personal submarines), no adverse weather, plus cool creatures to watch swimming around outside your window.
My mind was blown when I first heard that heat dissipation would likely be the key shaping factor in space battles.

I think this was the video https://youtu.be/9Xs3mGhQGxM

The pew pew of space lasers are just to heat up the enemy ship and then they blow up of their own accord
A hot object will radiate heat as infrared. The hotter it is, the more heat it will radiate. So, a sufficiently large heatsink designed to exploit that, can cool even in a vacuum. (Theoretically, this could even be used for reactionless propulsion.)

In the 70s and 80s, the USSR launched a whole series of radar satellites that were powered by several generations of nuclear reactors: https://en.m.wikipedia.org/wiki/RORSAT

Liquid metal coolant, as you suggested. Also, direct thermionic conversion to electricity -- no heat engine cycle. No control rods either -- control reflectors outside the core. Very different kind of nuclear engineering than is needed down here on Earth. No shielding!

A fun fiction novel by John Sanford, Saturn Run, presents a neat solution for the problem of heat dissipation, in space. Fun read.
Yea I loved that book, and not even a huge fan of sci-fi.
Will this future moonbase be before or after the UK rejoins the EU?
We can't even reliably build them for anything approaching a sane cost on Earth. I hope they're going to build a bankruptcy court up there, too
The cost on earth is mostly due to the regulatory environment. The moon doesn’t yet have the same regulatory environment.
The current nuclear station program in the UK seems to be struggling to keep up. I'm not sure how we will cope on the moon. Also, wasting money on a vanity project.

As for extra terrestrial law, research online reveals there to be a highly developed and powerful judicial system throught the whole galaxy. i have no doubt it is can hear lunar bankruptcy cases too.

Reactor going pop on the moon is a science experiment, not an biological tragedy.

Big fan of this idea.

We can and we have, then we stopped.
ChatGPT had fun with this one. Pretty soon YouTube will be replaced with ITube and we’ll have blockbusters on demand.

> In the pulse-pounding sci-fi blockbuster, Lunar Armageddon, the British government enlists Rolls-Royce to construct a series of nuclear reactors on the moon as the last hope for saving Earth from an imminent energy crisis. When legendary pinstriping artist Mark "Marksman" Court is recruited for his unique skills, he joins forces with the fearless commander, Emily "Em" Walker, to assemble an elite team of astronauts and experts. As they race against time to complete the high-stakes mission, Court and Em must navigate political intrigue and life-threatening challenges on the treacherous lunar landscape.

I wonder which endgame is more probable: satellite, or space ship? We have people perfectly willing to shroud earth in sulphur to “protect” us from the sun, so who’s to say those same types won’t repurpose the moon into a luxury spacecraft and take it on a joyride to distant stars?
If I am to take your reply seriously, you mean colonize the moon with ultra rich people and then turn it into an arc ship to settle a new world?

I mean, billionaires don’t strike me as the kind of people who would want to barely scrape by with limited access to air, water, food, sex, security, shelter until they finally perished cold and alone in the nothing.

> If I am to take your reply seriously, you mean colonize the moon with ultra rich people and then turn it into an arc ship to settle a new world

Yes, I said it in a jokey way but I’m actually seriously speculating about that as a distant future scenario, though I’d include their servants, clones, entertainers, staff, recruits, and progeny in that, along with probably a DNA bank of every person, animal, and strand of bacteria on earth.

> with limited access to air, water, food, sex, security, shelter until they finally perished cold and alone in the nothing

Who said anything about that? I mean, they’d be “limited”, yes, in the strictly mathematical sense that these things are finite, but they need not lack in abundance. I did say luxury space craft, didn’t I? I’m not talking about heated seats here, I’m talking nuclear powered underground cities…

Also, just a side point but I don’t think billionaires value comfort as much as you think. If that was the case they probably would have stopped somewhere in the tens of millions.
Is it me, or is the UK government launching an unusually large number of boondoggles lately? Nuclear reactors on the moon. Attempts to become a major player in battery technology. It feels to my jaundiced eye like the UK is trying just a little too hard to remind the world that they still matter.

Some Brexit insecurity might explain this, perhaps, but that was over five years ago.

Local elections in May and general election (likely) next year. And we’ve just had the Budget

I think there’s plenty of Brexit insecurity still lol

The Tory party has a trashed reputation currently so they’re trying to reclaim some ground

USA has secretly gotten ahead of the quantum race.

Part of their disclosure plan is it work with allies on multiple needs.

With fusion on the horizon, we will need batteries.

With electromagnetic craft, moon trips will be easy.

Secretly? QC companies have been shouting every tiny bit of progress from the rooftops, usually before it gets made.
That’s because the military already had it. They are just now getting bits and pieces.
Fusion isn't on the horizon. And batteries are needed for EVs and Solar/Wind.

And electromagnetic craft are a terrible way to get to the moon.

Why is it terrible? Using microwave emitters in a superconductive hull, and with enough energy, can engineer the pulling mechanics of the superforce.

This is all stuff the military has explored

Their economy is in decline, they need to do something to change the trajectory.
"Something must be done. This is something. Therefore, it must be done." - Yes, Minister.
USSR economy was in decline. So they built Buran (copycat of Space Shuttle), and Tu-144 (copycat of Concorde). Both are extremely costly, and that helped USSR to fall sooner.
They tried launching satellites two months ago in their first ever rocket mission and it failed.

Something pretty routine for Russia, US and China and even heavily sanctioned Iran.

No they didn't. It simply a US company that flew a plane out of the US.

The failure had nothing to do with the UK.

As we all know doing something new requires immediate success or it isn’t worth pursuing.
When you fall off a horse, do you get back on? Personally I head straight home and refuse to even look at a horse ever again.
This is the usual amount - they just dont normally force the journalists to write about every grant that gets handed out.
Reminds me of the first episode of Space 1999 where nuclear explosions on the moon push it out of orbit (not implying there will be explosions, just a nostaligic memory brought up by this news)

https://www.youtube.com/watch?v=Y6BXaGEuqxo&t=2314s

Now there was a series which really required "willing suspension of disbelief" of even a child's scientific understanding!
$3.5 million sounds like a drop in a bucket for a nuclear reactor.
Only if you care about nuclear contamination of the surrounding environment.
> The new boost to Rolls-Royce’s research pot follows a previous $303,495 (£249,000) study funded by the U.K. Space Agency in 2022

Wish them all the best, really. But I'm really curious what the study actually provided/concluded in terms of the stated goal of using the money to research the development of such a reactor. Because unless the British are so much more efficient than the EU for example, this kind of money just bought a short conversation with McKinsey.

P.S. I think it bought a press release [0].

[0] https://www.rolls-royce.com/media/our-stories/discover/2023/...

A small conversation with McKinsey can go a long way in terms of influencing public policy.
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Probably nonsense. A press release to feed the Brexit part of our politics and population that we're still relevant in terms of global influence and technology.
The US army used a miniature nuclear reactor to power Camp Century in Greenland in the 60s [1]. Obviously that base had some important differences to a moon base (like being surrounded by water ice and atmosphere) and technology has advanced a bit since then, but I wonder how much you would have to change the design to make it a viable moon base.

1: https://en.m.wikipedia.org/wiki/Camp_Century

The US Navy made a nuclear reactor to power an Antarctic base and it was so expensive and failure prone they went back to diesel.

https://theconversation.com/remembering-antarcticas-nuclear-...

(1961)
If you're marking the date implying the technology has improved since then, I'm going to need some convincing. List of cancelled nuclear reators in the US on Wikipedia[1] says

"By the end of the 1970s it became clear that nuclear power would not grow nearly as dramatically as once believed. [...] Eventually, more than 120 reactor orders were ultimately cancelled and the construction of new reactors ground to a halt."

"Of the 253 nuclear power reactors originally ordered in the United States from 1953 to 2008, 48 percent were cancelled, 11 percent were prematurely shut down, 14 percent experienced at least a one-year-or-more outage, and 27 percent are operating without having a year-plus outage. Thus, only about one fourth of those ordered, or about half of those completed, are still operating and have proved relatively reliable"

"As many as 30 new reactors were planned by 2009. As of February 2021, only two new reactors are still under construction, both at Vogtle. The project has announced significant delays and budget overruns. Most of the other new builds and the equally extensive list of upgrades to existing reactors have been shelved"

And the story is similar in the UK. (NB. that's not saying "one outage in a year" it's saying "an outage lasting at least a year".)

Nuclear power has not had the 70 years of intense funding, competition, year on year improvement that computing has had. There's fewer nuclear plants now in the UK and USA than there were in the heyday. Yes civilian nuclear tech and military tech will have improved somewhat, but the idea that we just wait 70 years of not running nuclear reactors in remote hostile places and now suddenly we'll be much better at it doesn't sound very plausible.

[1] https://en.wikipedia.org/wiki/List_of_cancelled_nuclear_reac...

It's an early reactor, sited poorly, with relatively weird operating constraints due to international agreements about the south pole. I agree the moon shares a lot of the same problems.

I don't think shipping in diesel is viable for the moon, though, which sort of changes what is cost effective.

This is a funny attempted dunk on US Navy nuclear considering they operate a fleet of nuclear powered submarines and warships.
The benefit of nuclear powered ships/submarines is that they can operate for a very long time without refueling - despite being extremely expensive, that can be a tradeoff the planners are willing to make.
I think the Navy has actually shown that nuclear for those ships is cost competitive. Refueling a large ship for decades is expensive.
Are you sure it wasn’t a navy reactor? The VA says it was operated by the navy.

It sounds like the Antarctic design deserves some ridicule.

https://www.publichealth.va.gov/exposures/radiation/sources/...

Edit: A history of the plant: http://large.stanford.edu/courses/2014/ph241/reid2/

It was an army plant, the reactor is listed here: https://en.m.wikipedia.org/wiki/Army_Nuclear_Power_Program

In that case the original commenter was wrong calling it a Navy reactor.
My comment link has a link to[1]: which is the Bulletin of the Atomic Scientists saying

"The Navy shuts down and dismantles a nuclear reactor in Antarctica", "Sometime soon the US Navy will have to find some place to quietly dispose of [...] by-product of 10 years of operating a small military power reactor in Antarctica", "The Navy considered nuclear power particularly suitable for the inland bases, where oil fuel was being flown in over such long distances[...]", "all the electricity for the 1,000 men stationed at the Navy's McMurdo Sound".

McMurdo station[2] "built by the US Navy Seabees".

Army Nuclear Power Program on Wikipedia[3] "PM-3A: 1.75 MW electric, plus heating and desalinization. McMurdo Station, Antarctica. Owned by the Navy."

[1] https://books.google.se/books?id=wwoAAAAAMBAJ&lpg=PA32&ots=V...

[2] https://en.wikipedia.org/wiki/McMurdo_Station

[3] https://en.wikipedia.org/wiki/Army_Nuclear_Power_Program

> The US Navy made a nuclear reactor

Still wrong, made != owned

If you want to make a shitty throwaway account to just post "wrong wrong wrong" and ignore citations and evidence, can you do it somewhere else?

Change "Navy made a nuclear reactor" to "Navy comissioned, owned, operated, bungled, mismanaged, wasted millions of taxpayer dollars on, a nuclear reactor". Happy?

It's listed there ... as "owned by the Navy" and "The PM-3A was not operated by the Army, but was under the NAVFAC (Naval Facilities Engineering Command), the shore-based power division of the US Navy."
It isn't an attempted dunk on US Navy nuclear, it's an attempt to say that humans failed to run a nuclear reactor in Antarctica, why think one will be any easier on the moon? The crew is way more expensive, spare parts are not available, tools are not available, there's no bulldozers or other way to move 12,000 tons of contaminated rocks away from the area like they had to do in the Antarctic, plus solar is so much better these days than the 1960s and the moon has no atmosphere to get in the way of it.
> the moon has no atmosphere to get in the way of it.

The lunar night is 14 days long

A VC I'm familiar with is in two modular fission reactor ventures. I was generally skeptical about a future for fission reactors, but it behooved me to learn. Among the things I learned is that there is a huge distance between making a small reactor and making a reactor of any size that can run unattended or with minimal supervision. Taking a reactor out of a nuclear powered submarine just gets you the small reactor bit. Much of what new gen fission projects do is to make reactors easy and safe to operate.

Submarines are run by a crew of trained specialists at all kinds of high stakes systems, including the reactor.

But do we need unattended reactors for the moon? Adding a "nuclear reactor tech" person to the mission control room in Houston sounds cheap compared to R&D costs, latency to the moon is small, and for any hands-on tasks you can presumably train the astronauts (or train a couple experts as astronauts if you want to vindicate the plot of Armageddon). After all, just like a submarine a moon base would be staffed by trained specialists.
Sure, but many fewer of them. There are over a hundred people on a submarine crew; it’ll be a good while before a moon base gets anywhere near that big.
That is a good question. Even on Earth, a large number of small reactors may not be better than a small number of large reactors. Pebble bed reactors might be inherently safer and easier to operate, but the German demo reactor got its pebbles jammed and they can't figure out what to do with it. Fast reactors can consume what is otherwise high level waste, but they also have risks.

On top of all that, are fission reactors compatible with VC fund liquidity horizons? I think that may be part of why some startups are focusing on operating instrumentation and software. You can patent that and sell it as a product separate from the reactor. Or worst case backstop your investors from losing their whole investment.

Submarines also operate in the world's largest heatsink.
Amongst other things, it would provide for powering installations on the dark side of the moon where there is no solar power.
The "Dark side of moon" gets sunlight. That's just what we call it because it never faces us.
You're right of course. Bad choice of words. I was meaning the the moon's "Permanently Shadowed Regions" [1]

[1] https://moon.nasa.gov/resources/97/the-moons-permanently-sha...

While solar obviously would not work there, is there any compelling reason to need nuclear power in those permadark locations?
It's not that reactors are needed in the permadark regions, it's just they they tend to be very cold and it should be easier to dissipate heat from the reactor.
I think there is reason on mars - there is a fairly significant source of water there (ice). I guess this wouldn’t explain the moon though.
The darker locations are co-located with the largest water ice deposits which are exciting for the possibility of a human presence.
And both sides have 14 day long days, and 14 day long nights. Only at the poles is there access to solar power all cycle long. Hence, reactors.
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…or build at the poles and have the solar arrays set up on a system that lets them pivot?
Yes, I specifically mentioned the poles.

It's likely we'll want to go other places eventually, though, and then you're back to reactors, or carting around enough batteries to last you two weeks.

"There is no dark side in the moon, really. Matter of fact, it's all dark. The only thing that makes it look light is the sun."
It will be interesting to see a modern design, rather that the something based on 1930s physics, 1940s construction methods, built in the 1950s and put into use in the 1960s like some of these military reactors they used for remote bases.
No matter the design, it’ll be built by lowest bidders around the world. /s
Clearly you have never heard of cost plus contracts.
"Rolls-Royce plan to have a reactor ready to send to the Moon by 2029". With that deadline I would expect something closer to a proven submarine reactor adapted for an environment without abundant water and fewer convenient ways to get rid of heat.
I'd think a similar design, or at least at a similar scale, would get ruled out by the necessary shielding. That would be quite a lot of mass to land on the moon.

Some innovation is in order. Mass reduction and radiation safety are among the highest design priorities I'd say.

In flight, it can be shielded with water and polyethylene, which would be needed anyway by colonists. On the surface, as someone else noted, you want good ground contact for heat dissipation so you might as well throw it into a hole and bury it, dirt being plentiful.
Once you're on the surface you can sink a fair bit of heat into the ground. The issue in space is that you can't do convection, and there's nothing to conduct to, so you're really just left with giant, inefficient radiators.
Nitpick: Are radiators very inefficient? I assume they're 100% efficient, just not very effective due to the limits of physics.
Depends on what you mean by efficient. I assume the previous commenter meant it isn’t efficient in terms of cost and space to build large radiators that aren’t very effective.
Yes, efficiency here is in the sense of the mass and volume of device required to dissipate X amount of heat energy, particularly in an environment where getting a lot of mass and volume up there is fabulously expensive.
Not a physicist, but I'd say it depends on what you define as parameter optimized against. For space, Id be interested in heat energy dissipated per unit time per kimogram per cargospace for exanple, where radiators suck compared to convection coolers
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On the moon, wouldn’t heat be a useful byproduct? (At least during the night) so a combined heat and power station would put those radiators where the people are
Up to a point, but you'd still need a story for dealing with the surplus.

Also, if you want to actually turn heat into electricity with a turbine, then you need the ability to heat and cool your medium repeatedly [1]— locating power plants on shorelines is very convenient for this, since you have a heat source from your combustion, nuclear reaction, whatever, and then a functionally bottomless cooling source in the water.

[1]: https://en.wikipedia.org/wiki/Rankine_cycle

NuScale also still plans on a first reactor by 2027 even though are ahead in the small nuclear reactor space
Small nuclear reactors are not proven though and are quite a risky idea since nuclear benefits significantly from scale.

If your goal is to produce something that's useful in a short time span, it's better to use proven tech.

The moon is being bombed routinely with space debris so technically is an interesting engineering problem.

The same meteorites that create craters in the moon would fall over a nuclear plant so I assume that would need to be put in the face of the moon that is closer to Earth. Otherwise this would mean having several local areas of the moon contaminated and forbidden forever in a few years. Not wind, animals or water in the moon, so apart of the ejected dust, radioactivity should remain in the same place at least

Given the complete lack of shielding that we get from the magnetosphere and atmosphere I am guessing that a few kg of scattered enriched uranium is going to be background noise on the moon. The target is small, the moon is (relatively) big and we can bury the reactor; a meteor strike on the reactor is probably less of a concern than a similar strike on any habitat to which the reactor it meant to provide power.

A recent Chinese probe has shown that lunar regolith is radioactive just from cosmic ray bombardment, so as a general rule I am guessing that future lunar operations will treat the entire lunar environment the same way we treat places like Chernobyl. Shield everything, watch your dosage and exposure, and do everything possible to prevent inhalation/ingestion of particles from the external environment.

Since RR make submarine nuclear reactors for the UK's fleet already, yes.
Heat , what heat ? I've heard that the moon is cold.
> The new boost to Rolls-Royce’s research pot follows a previous $303,495 (£249,000) study funded by the U.K. Space Agency in 2022

> helping to create jobs across our £16 billion space tech sector

If the space tech sector is £16bn, why is it news that some corporation (£13bn+ revenue) earned a 249k grant? It reads like a Monty Python script.

It's just a press release
I think this means that a previous iteration of this effort had a value of £249,000. The article is mainly about the current iteration, which has some other total value that is presumably larger. It isn't clear how much the current iteration is worth, at least from the article alone.

In general I agree that this might not be significant, unless the total value of the current contract is large or there are notable research or engineering results.

Specifically, this new stage of the project has £2.9 million of new funding, according to the linked press release. Still feels like pocket change, I wonder how much they can really do with that little
are there any fissionable materials that can be refined on the moon?
The weight of the fuel is the least of the concerns with this scheme.
but getting into an accident and spraying it all over during liftoff is something of a concern
I'd still like to know how they plan for a potential explosion of the space craft carrying the fuel inside the atmosphere. They better have a good story on that.

Even if the rocket breaks up and the fuel reaches ground in perfectly sealed containers, that still doesn't mean the danger is over.

I imagine step one is to launch from the coast heading out over the ocean. If Starship is fully operational by then it would be the obvious choice and depending on the reactor design there might be enough weight capacity to build in some extra shielding. I also wonder if the fuel can be shipped separate from the reactor.
The fuel doesn't become dangerously radioactive until after the reactor powers up for the first time. The uranium fuel is only about as toxic as something like barium or lead until the chain reaction starts generating fission products.

This is in fact safer to launch than past space missions such as Pioneer, Voyager, and Cassini. Those used radiothermal generators that were far more radioactive and hazardous than a fresh reactor core.

The same plan as for all the countless cases when they sent radioisotopes in space. Perseverance and Curiosity each have 4.5 kg of Plutonium-238 on board. Did that worry you?
Yes. And the lunar reactor will require more power and thus more fuel.
This article does not cover what I consider to be two key issues:

- how to boost the mass of something like a shielded nuclear reactor to the moon?

- how to extract the heat energy from the reactor? turbines (more mass)?

Maybe reduce the shielding requirement by burying it in regolith with only the heat exchangers exposed?
also wondering the same. Most nuclear reactors including those in submarines (which rolls royce make) are basically steam engines.
If we had those answers already, there wouldn't be a project to fund to find out those answers.
When all you have is a hammer, nothing looks like low cost continuous solar power with direct conversion to electricity at the poles.
I guess they aren't planning to build the moon-base at the poles, which could provide access to continuous solar power nearby. The rest of the moon has long (+/- 14 day) lunar nights, and getting enough batteries or whatever to the moon to last that long is likely to be impractical/expensive.
Because it's too cold there? Probably too much water ice on the poles to be interesting.

https://www.nytimes.com/2020/10/26/science/moon-ice-water.ht...

oops

https://web.archive.org/web/20201101003308/https://www.nytim...

It's certainly very cold deep in the polar craters, which are in permanent darkness. But in the sunlit areas it's relatively mild. There's far less variation than in equatorial regions, which have to deal with huge variance between day and night temperatures.
… but why Rolls Royce?

Also interesting that they didn’t pick a US nuclear company. This is obviously a boon to the contract winner. These decisions always have a political aspect to it. What does this signal?

Edit: wow, massive oversight. I thought this was NASA. Nevermind! Still, the Rolls Royce choice isn’t obvious to me.

Along with making fancy cars, Rolls Royce is a significant aerospace engineering company well known for their jet engines. https://www.rolls-royce.com/
Car brand is owned by BMV. RR now is primarily known as a defence contractor and jet engine manufacturer (and other powerplants).

To answer your original question, Rolls Royce is a major job provider in the UK. This is probably an attempt to revive it in addition to building it. A lot of these are job programs first.

https://en.wikipedia.org/wiki/Rolls-Royce_Motor_Cars

Still, I would be surprised if the US government commissioned a reactor from Pratt and Whitney.
But not General Electric, right?
But Rolls Royce is a nuclear company, Pratt and Whitney is not.
More relevant for this case is that they are also involved in Submarine propulsion, which usually means nuclear. So I would guess that they have significant experience.
Ever flown in an Airbus or newer Boeing? You're flying Rolls Royce.
> "the Rolls Royce choice isn’t obvious to me."

Well, this is being funded by the UK Space Agency, and Rolls-Royce is the only UK company that manufactures small nuclear reactors that could be adapted for the lunar environment. Seems pretty obvious to me!

Rolls Royce already makes the nuclear reactors for the UK's current fleet of nuclear submarine, and is developing the reactor for the new SSN-AUKUS subs that are currently in the design phase. They also market a modular reactor for civilian applications. Presumably these are all based on a common core design and the research grant is to adapt it for space applications.

https://www.rolls-royce.com/innovation/small-modular-reactor...

RR the aerospace company and RR the car company were split apart in the 1960s. The have had nothing but the name in common for many decades.
This reads like a madlib, it can't be serious. Who's embezzling money here?
First my pocket computer hugely outperforms my 90’s desktop, space rockets get privatized and much cheaper, there’s probably an actual AI online, and now we’re putting a nuclear reactor on the moon. Awesome! (I hope)
Hey sweet, my existence is pointless!
You have to be extraordinarily cynical to not be at least a little excited
Can we build them for earth too? We need to quit oil yesterday.
The largest terrestrial consumer of oil is road transport (cars and trucks).

https://www.statista.com/statistics/307194/top-oil-consuming...

You can't put a nuclear reactor in a car. You can charge an electric car's battery using nuclear electricity, of course. But if you're just charging a terrestrial battery then nuclear power's attractive attributes for the Moon (like continuing to produce during a 14 day period of darkness) are less salient. Electricity sources like wind and solar power are likely to charge up the car's battery at lower cost.

  You can't put a nuclear reactor in a car. You can charge an electric car's battery using nuclear electricity, of course. But if you're just charging a terrestrial battery then nuclear power's attractive attributes for the Moon (like continuing to produce during a 14 day period of darkness) are less salient. Electricity sources like wind and solar power are likely to charge up the car's battery at lower cost.
You don't need batteries if the energy is readily available throughout the route.

Examples:

1. Buses that use capacitors https://en.wikipedia.org/wiki/Capacitor_electric_vehicle

2. Trains / Bullet Trains / Trolleys that could have that energy along their line.

Car dependency could be rapidly reduced if we truly wanted.

Yeah car and road-centric culture holds a lot of this stuff back. In any urban area an efficient metro underground/elevated/tram metro system could take up a huge percentage of journeys.

If high-speed electrified rail links exist between cities, they can become much more attractive than long car trips.

On-demand transit can fill a lot of gaps in rural areas (e.g. on-demand bus routing)