Please explain how you would design a thorium reactor to produce 238Pu suitable for use in RTGs.

Please explain how you would build a shiny new thorium reactor with 238Pu production capability on a budget competitive with the existing DoE 237Np -> 238Pu transmutation process in an existing research reactor.

Take a look at http://www.thoriumenergyalliance.com/downloads/plutonium-238... for how it could be done

Please see: Liquid fluoride thorium reactor

The wikipedia page doesn't say much about Pu-238, but there is this under the "Proliferation resistance" bullet:

"...LFTRs produce very little plutonium, around 15 kg per gigawatt-year of electricity (this is the output of a single large reactor over a year). This plutonium is also mostly Pu-238..."

https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reacto...

In a LFTR the fuels are dissolved in liquid salts, so the downside is it may be very difficult to separate out the Pu-238 for use.

Yeah, weird why that is getting down-voted.

It should get down-voted.

The original post was two words. Okay, cute. But then the subsequent "explanation" was four words.

There should have been at least a sentence or two of explanation. At the minimum there could have been a link to Wikipedia. That's common courtesy.

Most people don't come to HN to spend decades learning obscure things, very slowly, from Zen masters.

Every time someone gets all giggly about Thorium I'm suspicious. Could you provide some documentation about why this is a viable option in space?

AFAIK it's because they last a long time with very small amounts of reactants, are low maintenance, and are potentially very small. I mean, it kinda makes sense but RTGs are better for space applications because you really don't need massive amounts of power in space, plus the whole "power forever with no effort" aspect; they might as well be perpetual motion engines.

I agree thorium isn't without its problems, but the end byproduct of a lftr reactor is plutonium.

LFTR's produce 239Pu (among a mess of other stuff), that's the stuff that goes BOOM in nuclear bombes, not 238Pu that glows warmly to make power for spacecraft.

As Jobu points out from Wikipedia: he second proliferation resistant feature comes from the fact that LFTRs produce very little plutonium, around 15 kg per gigawatt-year of electricity ... This plutonium is also mostly Pu-238. According the article this seems like quite a bit more than is currently being produced, is it not viable for use in RTGs for some reason? Or is the cost of a LFTR over the course of a year less cost effective than the current method of Np to Pu?

I have very little knowledge of the science here, I'm just not sure what all I'm missing.

I have no idea what you're getting at here. If you mean we should use a Thorium reactor to generate Plutonium then others have explained why that's impossible. If you mean that we should use a Thorium reactor instead of a Plutonium RTG then that also wouldn't work, the smallest reactor is still way heavier than an RTG.

The Thorium Dream (Documentary): https://www.youtube.com/watch?v=GQ9Ll5EX1jc