[apendleton]

I'm super-interested in thorium reactor research, but this author seems to lack even a cursory understanding of the issues at play. This reactor differs from what lots of thorium advocates are aiming for because it's a solid-fueled, high-pressure, water-cooled reactor, instead of the proposed LFTR designs, which involve a reaction taking place in a liquid at very high temperature, but at atmospheric pressure, and thus have a different set of tradeoffs as far as efficiency, safety, proliferation resistance, etc.

This article discusses none of that, and instead suggests that this reactor is sub-optimal because it's not a cold fusion reactor -- what? Thorium atoms are big and somewhat-unstable, which is what you want for fission. For fusion, you want little atoms you can ram together to make slightly-bigger little atoms. They're totally separate.

[ChuckMcM]

In order to make Thorium successful you have to consider the consequences. The Nuclear Power industy has been under attack now significantly longer than it was "the next big thing" (during the 50's it was 'cool' and starting in the mid-sixties on it has been 'un-cool') Long enough that all it knows is 'attack.' If someone says "This will make all our Nuclear reactors obsolete!" it makes Thorium an enemy that must be killed. But if you say "This works with your existing reactor and the spent rods are more easily disposed." Then its a 'friend' of the industry. So making fuel rods with Thorium that are compatible with existing designs is a Big Deal(tm).

[dragontamer]

You're right, the author clearly doesn't know what he's talking about. But the story is still interesting nonetheless. :-)

Its great to hear news that Thorium is finally on the path to adoption.

[tankenmate]

Unfortunately the type of reactor they are building is not as safe as a LFTR, nor does the fuel in this type of reactor last as long; the LFTR reactor is a type of fast breeder reactor. It will still need to be fed pellets continually. The only two material difference between this kind of reactor and a normal boiling water reactor is that it is capable of "burning" a small amount of uranium and/or plutonium a year (either from spent fuel or new sources), and the spent fuel is far less radioactive after a full burn (a full burn is not always the case). It still has most of the other safety issues of a boiling water reactor.

[tkolsto]

I'm pretty sure they have not actually built any new reactor this time around. AFIK they are testing in the Halden reactor[1][2] from the late 50s. It's one of only two reactors in the country, both used mainly for research and testing, so the pellets feeding issue you mention is a feature not a bug :)

[1] https://en.wikipedia.org/wiki/Halden_Reactor

[2] http://www.ife.no/en/ife/halden/hrp/the-halden-reactor-proje...

[DennisP]

Just a nitpick, the LFTR isn't a fast reactor, though it is a breeder. Thermal reactors breed thorium to U233 just fine. Some people have proposed fast molten salt reactors but those designs aren't as far along.

[aidenn0]

Furthermore, isn't Th no better than U-238 for fast-reactors (and we have huge quantities of U-238)?

Also, isn't the neutron economy of LFTR just slightly above unity? IIRC chemical removal of fission byproducts was needed for a feasible Th reactor that generates excess U-233. At least that was my recollection that one of the potential advantages of the FLiBe design was for such very simple chemical reprocessing.

[DennisP]

True, they have similar advantages, very efficient fuel utilization and little waste.

Some of the engineers involved in molten salt reactors say "come for the thorium, stay for the reactor." Liquid fuels offer several benefits. Removing fission products continuously helps you achieve high burnup. There's no fuel fabrication cost. And if the electricity cuts off, a frozen plug melts and all the fuel dumps into a passive cooling tank, with little worry about decay heat since you've been removing those fission products.

The neutron economy is arguably an advantage from a proliferation perspective, since you can't remove much fissile without the reactor shutting down.

Still, a good fast reactor like the IFR has its own charms. The metal fuel is easy to fabricate on-site, and they tested electricity cutoff and it quietly shut down just fine, due to the physics of the fuel and coolant. And the mixed plutonium isotopes produced by the reactor are very difficult to refine into weapons-grade.

One advantage of the molten salt reactor is that there's nothing in the reactor that can drive any kind of chemical explosion, like the hydrogen that blew at Fukushima. The IFR uses molten sodium, which is pretty reactive with air and water. That might not be too terrible to deal with but it does drive up the cost.

Another advantage of the IFR though is that we've got a production-ready design ready to go.

[mrsebastian]

You're right, I know very little about nuclear reactors. (I'm the author.) Enough to get by, but not enough to be an authority on every variety of them.

Hopefully enough to write an interesting story, though :)

[geuis]

Why write a story about something you don't understand? I don't want to sound too critical, but you do a disservice to this technology and the people involved if you don't get the facts straight.

I think you did a reasonable job, but the add-in about cold fusion didn't make any sense and really affected the seriousness of the article. It calls into question whether anything else in the piece is valid or not.

There are tons of people here that have expertise in these fields. Some of them are commenting on this very page. Why not develop relationships with people that can provide domain expertise as needed for stories like this, rather than trying to wing it?

[mrsebastian]

I'd love to do that! But it's just not feasible for me, when I'm writing multiple stories a day, about very disparate topics. If it was a feature about thorium power, and I had a chance to do my research, it'd be a different story :)

(I do have quite a few expert friends who I lean on for domain expertise, but as luck would have it, my nuclear guy wasn't online when I wrote this.)

[dragontamer]

I did journalism in high school. It was tough enough to write an article once a month for the monthly paper, so I get where you're coming from.

The news of "Thorium Reactors exist somewhere" is good enough to report on, and happy news indeed. :-)