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UK backs Rolls-Royce project to build a nuclear reactor on the moon

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Re: UK backs Rolls-Royce project to build a nuclear reactor on the moon

#111

Post by Zigurd »

wongarsu wrote: post #72
Zigurd wrote: post #66

Earlier quoted context omitted.

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…

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 trai…

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.

Re: UK backs Rolls-Royce project to build a nuclear reactor on the moon

#112

Post by s1artibartfast »

Maursault wrote: post #77
stevenjgarner wrote: post #61

Earlier quoted context omitted.

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?

The darker locations are co-located with the largest water ice deposits which are exciting for the possibility of a human presence.

Re: UK backs Rolls-Royce project to build a nuclear reactor on the moon

#113

Post by tadfisher »

nonethewiser wrote: post #105
cdot2 wrote: post #97

Earlier quoted context omitted.

Along with making fancy cars, Rolls Royce is a significant aerospace engineering company well known for their jet engines. https://www.rolls-royce.com/

Still, I would be surprised if the US government commissioned a reactor from Pratt and Whitney.

But not General Electric, right?

Re: UK backs Rolls-Royce project to build a nuclear reactor on the moon

#114

Post by system16 »

wongarsu wrote: post #55

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

McMurdo as well: https://en.wikipedia.org/wiki/McMurdo_Station#Nuclear_power_...

Re: UK backs Rolls-Royce project to build a nuclear reactor on the moon

#115

Post by ambicapter »

mikepurvis wrote: post #85
wongarsu wrote: post #74

Earlier quoted context omitted.

"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.

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.

Re: UK backs Rolls-Royce project to build a nuclear reactor on the moon

#116

Post by kurthr »

zabzonk wrote: post #90

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)?

When all you have is a hammer, nothing looks like low cost continuous solar power with direct conversion to electricity at the poles.

Re: UK backs Rolls-Royce project to build a nuclear reactor on the moon

#117

Post by u320 »

nonethewiser wrote: post #105
cdot2 wrote: post #97

Earlier quoted context omitted.

Along with making fancy cars, Rolls Royce is a significant aerospace engineering company well known for their jet engines. https://www.rolls-royce.com/

Still, I would be surprised if the US government commissioned a reactor from Pratt and Whitney.

But Rolls Royce is a nuclear company, Pratt and Whitney is not.

Re: UK backs Rolls-Royce project to build a nuclear reactor on the moon

#118

Post by brokencode »

ambicapter wrote: post #115
mikepurvis wrote: post #85

Earlier quoted context omitted.

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.

Re: UK backs Rolls-Royce project to build a nuclear reactor on the moon

#119

Post by go_elmo »

ambicapter wrote: post #115
mikepurvis wrote: post #85

Earlier quoted context omitted.

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.

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

Re: UK backs Rolls-Royce project to build a nuclear reactor on the moon

#120

Post by mikepurvis »

brokencode wrote: post #118
ambicapter wrote: post #115

Earlier quoted context omitted.

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.
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