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by beefman 4034 days ago
The zirconium hydride moderator is a genuine innovation, allowing much higher core power density than LFTR, and higher conversion ratios without HEU (assuming their modeling is correct). But like LFTR, you've got loose FPs all over the place and it's hard to see that being acceptable in anything like the current culture. Meanwhile, it's hard to see any benefit from MSR.

Edit: There will likely be all sorts of materials issues. None of them damning. I'd worry more about FPs, tritium fluoride, etc. than the salt itself.
2 comments
DennisP 4033 days ago
Why would the fission products be "all over the place?" They're contained in the reactor core, just like any other reactor.
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beefman 4033 days ago
Nope. Gaseous FPs are continuously removed and stored somewhere. Of course they require cooling while being stored. Any mishap releasing even a tiny fraction of them would of course be harmless, but in the present culture would result in a global panic.

Other FPs in the salt are circulated out of the core and through a heat exchanger. Some ongoing actinide fission there too. Tiny defects in heat exchangers handling plain water currently cause reactors worth billions to be abandoned (e.g. SONGS).

Some FPs will plate out and you'll need to replace plumbing periodically. That has to be done by robots because the pipes will be ultra-hot and deadly within minutes to anyone nearby.

For what benefit? You improve the fuel cycle by a factor of 50. But the fuel cycle is < 10% of the costs and material flows of nuclear plant. So yes, online FP separation is something a mature fission-based civilization would have. But it is not clear how it helps us, other than to provide a focal point for a new culture to form (which may be a substantial if illegitimate benefit, admittedly).

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DennisP 4032 days ago
Well ok that's true. On the other hand, removing fission products means you have a lot less decay heat to deal with upon reactor shutdown. Dump the fuel to a tank without moderators and walk away.

ThorCon has an interesting approach for dealing with plating and so on: their design has reactor cores that can be easily swapped out. When one's ready for maintenance they just cart it away, let it cool for several years, then deal with it.

http://thorconpower.com

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jessaustin 4034 days ago
Wild guess on "FP": fission product?
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beefman 4034 days ago
Yep. (Sorry, I was on mobile earlier)
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