Talk:Radioactive Rarity on Mars

Thanks for starting this!

What is the real energy available form Thorium? Reference 10 mentions 11 MWh/g. Or 11 000 MWh/ kg. Now this seems to be an individual personal page.

On the other hand, https://www-pub.iaea.org/mtcd/publications/pdf/te_1450_web.pdf , the International Atomic Energy Agency puts the value of energy from thorium at 15-60 MWd/kg

When I convert the first value of 11 MWh/kg to MWd/kg, I get 458 MWd/kg or 40 times more. This seems to be an error. Almost 10 times more than the best result to date. (There may be simply a confusion between day and hour)

I also have my doubts since for some reason the author of (10) puts uranium at 0,035 MWh/kg. I understand the burn up fraction is higher for thorium, but it's not 300 times higher. After all if uranium just burns 5% then we have a 1500% burn up fraction.

If we divide reference (10) by 40, we get instead of 11 000 $/m3, 275$/m3. If we use the Martian surface average that is six times less than the Earth average we get about 265/6 = 45$ of energy per m3 of Martian dirt, or 45$ for 2 tons, or about 23$ per ton of materials processing, where we manage to remove the entirety of the Thorium in a perfect separation process.

I fear we may be spending more $ to extract the energy that the revenue from the energy. It is just too diffuse.

This does not make thorium from Mars impossible, it just makes it less likely and dependent and a natural enrichment process that may not exist.

And if Thorium must come from Earth, this means the Martian colony is not energy independent and open to all kinds of pressures from Earth.

BTW the cost of fuel for nuclear reactor is not entirely negligible. It is about 1/2c per kWh. this seems like very little until we see that the price for solar in new installation can be as low as 2c per kWh in the US, and has been sold for less elsewhere in the world. Can more reasonable attitudes reduce the cost of reactor by 5? Perhaps. are they likely? And if the processing costs are high because mineral concentration is low, then the cost of nuclear just cannot keep up.

https://www.world-nuclear.org/uploadedfiles/org/info/pdf/economicsnp.pdf https://cleantechnica.com/2021/11/17/utility-scale-solar-reaches-lcoe-range-between-2-4%C2%A2-per-kwh-in-the-usa-record-low/

--- Most modern reactors burn 0.5% of their fuel, not 5%. They are WILDLY inefficient. Busy right now, will spend more time later. Rick.

-Are there any Thorium reactor that reprocess their fuel or is this a theoretical proposition? When I see thorium reactors at 40 MWd/ton, is it because they are being viewed as single cycle, and exclude fuel reprocessing? -Is a traveling wave reactor (25 to 40% burnup fraction) a viable alternative to thorium? -Can a thorium reactor be configured as a travelling wave and therefore do away with the reprocessing?

-Thorium in Martian thermal vents, from meteoritic data. Also good source for Rare Earth minerals. https://www.hou.usra.edu/meetings/lpsc2015/pdf/1287.pdf