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U.S. tests nuclear power system to sustain astronauts on Mars

reuters.com

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Re: U.S. tests nuclear power system to sustain astronauts on Mars

#121

Post by InclinedPlane »

baron816 wrote: post #2

What happens if the launch rocket fails? That’s been the main concern of sending nuclear reactors into space thus far, right? Has this been addressed here?

The reactor will be launched in a "cold" state, it will also be in a robust structure (though not as strong as RTGs, though that's unnecessary). The absolute worst case scenario is that you get a release of U-235. That's not great but on the scale of radiological hazards it's comparatively very minor. The reactor doesn't start generating fission products (aka "fallout" isotopes) until it's in space and operating, presumably with no chance of returning to Earth.

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#123

Post by tarre »

theptip wrote: post #88
tarre wrote: post #85

Earlier quoted context omitted.

In fact the fission[1] part in such small scale is hard. Curiosity and other probes using thermonuclear batteries harness alpha decay[2], which is relatively easy as it happens whether or not you want it to happen, but creates also much less power. In that case the hard part is to obtain material with appropriate half-life and other properties. Perhaps best material for this is Pu-238, which is far more expensive to…

I don't think "thermonuclear" is the right term for the batteries in probes. Wikipedia says "thermoelectric"[1], as the electricity is generated directly by thermocouples. "Thermonuclear" usually refers to the sorts of fusion reactions found in stars and modern nuclear warheads. [1]: https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...

Thanks for correction. Unfortunately I'm not able to edit it anymore.

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#124

Post by the_duke »

ageofwant wrote: post #68
the_duke wrote: post #63

Earlier quoted context omitted.

Please provide a citation for this claim. Chernobyl still is a massive cost factor for plenty of countries ( all that are helping out financially with building the new mantle ). Also look at the large effects of Fukushima. Every time nuclear power comes up here on HN, there are some fierce defenders. No matter how 'safe' newer generation plants are and how much it was the oprators fault, the potential for disaster is…

http://www.unscear.org/docs/reports/2008/11-80076_Report_200... Now please provide citations for your claims. Specifically 'Massive Costs' and 'large effects'. Nuclear power does not need to be safe, only saver than the alternatives, this includes long term pollution from solar panel waste. Every ounce of nuclear waste is entirely contained, every other power source's waste is dumped into the environment.

Your reference has absolutely nothing to do with economic effects.

Chernobyl costs for new "sarcophagus": 1.5bn (https://en.wikipedia.org/wiki/Chernobyl_New_Safe_Confinement, sources on bottom)

Fukushima cost: 188bn + (https://www.reuters.com/article/us-tepco-fukushima-costs/jap...)

Costs for decomissioning a nuclear power plant in the US: up to 500mil (https://www.nrc.gov/reading-rm/basic-ref/students/decommissi...) (which needs total cost and revenue to put it in perspective, but it gives a sense of the scale and difficulty of decommissioning and storage.

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#125

Post by tarre »

SigmundA wrote: post #100
tarre wrote: post #85

Earlier quoted context omitted.

In fact the fission[1] part in such small scale is hard. Curiosity and other probes using thermonuclear batteries harness alpha decay[2], which is relatively easy as it happens whether or not you want it to happen, but creates also much less power. In that case the hard part is to obtain material with appropriate half-life and other properties. Perhaps best material for this is Pu-238, which is far more expensive to…

Sorry I wasn't using the strict term of fission[1]. This reactor says it uses U-235 which would be full fission similar to the US SNAP-10A[2] or Russian BES-5 RTG[3] So yes the fission part is more complicated than a P-238 alpha decay RTG. Perhaps I mischaracterized the R&D complexity on the reactor portion, although it has been done before. 1. https://physics.stackexchange.com/questions/35303/alpha-deca... 2. https:…

I didn't know about those reactors. Interesting.

When writing the answer, I didn't even consider, that those reactors need to be fast reactors. In retrospect it is obvious, but makes controlling the power even harder.

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#126

Post by ethbro »

wbl wrote: post #81
ethbro wrote: post #80

Earlier quoted context omitted.

It was founded in North Carolina. The large number of freshwater waterways around there are generally known as black water.

That means something very different to sailors.

Pray tell?

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#127

Post by superkuh »

gene-h wrote: post #113
superkuh wrote: post #37

As far as I understand it they are pumping the equivalent thermal energy as an actual operating core would produce into the reactor casing and assembly using a specially designed electrical insert that uses external power. This isn't a fission test. It's a mechanical engineering test. Still cool.

They already completed the equivalent thermal power tests last year[0], and you most certainly don't need to do electrical tests at the Nevada Nuclear Test Site. How much progress they've actually made at this point is not clear from the article, but slides from a presentation they posted yesterday detail what they plan to test[1]/maybe already tested. They need to test the individual reactor components to measure re…

Thanks for the correction and a link to [1] which gives actual information on the tests. This is great news.

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#128

Post by rangibaby »

fb03 wrote: post #60
rangibaby wrote: post #27

Earlier quoted context omitted.

I haven't heard that before. 原子力(atomic, using atoms)+発電所(power plant) is the common term eg 福島(Fukushima)第一(No. 1)原子力(nuclear)発電所(power plant)

Gen-shi-ryoku Hatsu-den-sho? Let's see if I got it right, my Japanese is a bit rusty. I am not sure about the readings of the first two kanji (atomic) so I used generic ones heehe. Thanks in advance.

Yes you are right.

原子 genshi means atom. 力 means power (strength). Stick them together and it means using the power of the atom.

Re: U.S. tests nuclear power system to sustain astronauts on Mars

#129

Post by ekianjo »

ehnto wrote: post #21
ekianjo wrote: post #19

Earlier quoted context omitted.

How does pollution work exactly in an environment that's already hostile to life as we know it?

It adds one more element to overcome when we decide we would like to live there.

It's not like radiation is a non-existent problem to begin with on a planet that does not have enough atmosphere.
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