[Maxels]

So this is a company with a pretty ui that is advocating the same thing Kirk Sorensen has been advocating for a few years now.

I know every time this molten salt vs light water reactor debate comes up, people much smarter than I talk about how the salt is corrosive and there are currently no viable solutions to deal with this. Is there anyone out there smarter than I that can explain whether this company is doing anything different, or if it is just sexy and VC backed?

[apendleton]

They say the modified Hastelloy-N from the Oak Ridge experiment is good enough, though I suppose people who disagreed with that claim when it was presented by previous MSR advocates would still disagree now. They do also mention in their white paper, though, that it may eventually be possible to replace some of the Hastelloy-N with ceramic composites, which might be better still.

[beefman]

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.

[DennisP]

Why would the fission products be "all over the place?" They're contained in the reactor core, just like any other reactor.

[beefman]

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).

[DennisP]

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

[jessaustin]

Wild guess on "FP": fission product?

[beefman]

Yep. (Sorry, I was on mobile earlier)

[alexhill]

There are certainly solutions to deal with it by designing for leaks as an expected maintenance problem, though preventing them would obviously be preferable. There are numerous operating molten salt reactors around the world, so I guess it depends what you mean by viable: http://en.wikipedia.org/wiki/Breeder_reactor#Breeder_reactor...

[InclinedPlane]

Note that this is note exactly the same thing, Sorensen has been advocating a Thorium fuel cycle, these folks seem to be advocating a Uranium fuel cycle.