91–100 of 138 posts
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I don't think there is any uranium to be had there. For such heavy elements to get deposited in ore near the surface takes special circumstances, such as those of Earth.
What pertinent "special circumstances" do you mean?
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Nuclear reactors that have some service time on them are very, very, very radioactive. Just look what happens when a very small portion of that radioactivity finds itself into the atmosphere or water (Chernobyl, Fukushima, etc.) It is maybe not as big a problem if we never plan it to return to Earth or Mars orbit (reactor is not as radioactive until it actually is started), but if we are using it to supply energy to…
Exactly what do you think "happens" ? Not even Chernobyl, that had an atmospheric nuclear fire, the worst case scenario imaginable, had a economic, environmental or human live cost comparable to the impact of a single coal power plant. It really concerns me when people on this forum, that has no excuse to not know better, parrots this anti-nuclear FUD.
Aside from the headline numbers of 31 dead and 237 with acute radiation poisoning other costs include:
- Encasing the site in a sarcophagus that will need to be maintained essentially forever. Immediate disaster response was estimated at $18B in today's dollars.
- A 30km exclusion zone from which 135,000 people were evacuated. Costs from this include costs of resettlement, loss of essentially all capital, cropland, and infrastructure in the zone
- Outside the zone millions of tons of contaminated earth were trucked for containment. Remediation is ongoing to this day and will continue indefinitely. Certain agricultural production is limited by type and practice to reduce probability of contamination from deeper in the soil.
- Health monitoring response across Europe in the aftermath, plus increased monitoring forever in the neighboring countries
- An unknown number of additional cancers and birth defects
There are additional costs, mostly more evacuees than were likely strictly necessary and compensation to others affected. Its unclear how much of this are legitimate costs or not, but its worth noting that uncertainty and lack of transparency themselves have costs.
https://en.wikipedia.org/wiki/Chernobyl_disaster
https://en.wikipedia.org/wiki/Effects_of_the_Chernobyl_disas...
I find it frustrating NASA talking about putting people on Mars but if you look at reality, it can't even put astronauts in the orbit anymore. What about solving that problem first, and when it's done, then we can dream about Mars... Or are we going to outsource such mundane tasks like manned orbital space flight to the Russians and Chinese forever, while we are proudly preparing the colonization of Mars? /s
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Hi, just to point out a hole in your reasoning, if these reactors are so safe then why even a small portion of the radioactivity escaping the containment shell can cause such a big disaster like Fukushima or Chernobyl? Now, I understand there are differences in size and the level of radioactivity used (they won't be driven as close to prompt criticality as the power reactors) and they may be designed to be less relia…
> small portion of the radioactivity escaping the containment shell The Chernobyl reactor was very unsafe by modern standards, it did not have a containment vessel and tens of tons of reactor material was blown into the air, not a small amount.
And your comment conveniently ignores Fukushima.
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?
It is too bad that most people are so afraid of anything nuclear. I hate to say it, but maybe people working on nuclear power need to change the name. Isotopic power would have pretty bland associations. Uranium 235 is a very low level radioactive metal. Even if the rocket blew up, the isotopic fuel would remain intact (that is, not vaporized into breathable particles). The radioactivity from a Uranium 235 isotopic r…
Unanswered in article: How long does the power unit lasts until you have to replace the paper-towel-roll-sized U-235 core? Where are they going to put the old ones? What's the plug interface? Can I charge my iPhone? What about my electric razor? Are they going to test burying one in red sand for 15+ years and see if it can be dug up to phone home in an emergency?
And in 15 years, do you need to import a new core from Earth or what - have a uranium mining and refining operation up and running by then?
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> For a vehicle that is on a one-way trip to Mars, and where the reactor will be brought online after it's out of Earth's orbit, this isn't a problem. Polluting the new homeland from the start, eh?
Just bury it out back, we'll clean it up later just like we did in Hanford. No problemo https://en.wikipedia.org/wiki/Hanford_Site . More seriously, we can afford to have a small amount of nuclear waste there, but we need to plan for it better than we have previously. First, document where it is and what it contains. Second, I don't know.
The correct response is reprocessing. Most of the "waste" generated by power reactors is actually still usable as fuel. It also eliminates the really long-lived stuff, so that the small amount of leftover waste only has to be kept stored for a much more manageable 500-1000 years.
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From my understanding the fission part is "easy", the hard part is taking the heat and converting to electricity efficiently and reliably. The Mars Curiosity rover among other probes use a thermocouple based generators to create electricity from the fission heat[1]. Extremely robust , no moving parts, but extremely inefficient just a few percent converted to electricity the rest to heat. The heat is very useful on ma…
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…
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...