
Thorium reactors: Asgard’s fire - mblakele
http://www.economist.com/news/science-and-technology/21600656-thorium-element-named-after-norse-god-thunder-may-soon-contribute
======
apendleton
This article deserves a bunch of credit for reasonably clearly articulating
the distinction between thorium-powered molten salt reactors (the kind the
Chinese program eventually aims for, and that groups like Flibe in the states
want to build) and thorium-powered pressurized water reactors (like what India
is going for). Lots of the amateur enthusiasm for thorium power glosses over
the distinction, and while some of the benefits of thorium apply equally to
both (like proliferation resistance), others (like many of the purported
safety benefits) apply only to the MSR configuration, largely because it runs
at atmospheric pressure.

The downside of the MSR configuration is that it's way harder to build, and
involves some maybe-not-entirely-solved problems around corrosion resistance,
since the salts in question tend to be pretty reactive.

------
archgoon
Coincidentally, ASGARD is also a horrible backronym for another nuclear
related project.

 _A_ dvanced fuel _S_ for _G_ eneration IV re _A_ ctors: _R_ eprocessing and
_D_ issolution

[http://asgardproject.eu/publications](http://asgardproject.eu/publications)

~~~
twic
The new thorium design should be the Mega-Joule Operationally Limited Nuclear
Incident Reactor.

~~~
Consultant32452
MJOLNIR?

~~~
ColinCochrane
Thor's Hammer.
[http://en.wikipedia.org/wiki/Mj%C3%B6lnir](http://en.wikipedia.org/wiki/Mj%C3%B6lnir)

~~~
Consultant32452
lol, nice.

------
ColdHawaiian
There's a really interesting Ted Talk by Taylor Wilson (perhaps the world's
youngest nuclear scientist, and definitely a child prodigy) on thorium
reactors as a safer alternative to uranium and plutonium reactors[1].

Apparently there's also this talk[2] by Kirk Sorensen, but I haven't seen that
one yet.

[1]:
[http://www.ted.com/talks/taylor_wilson_my_radical_plan_for_s...](http://www.ted.com/talks/taylor_wilson_my_radical_plan_for_small_nuclear_fission_reactors)

[2]:
[http://www.ted.com/talks/kirk_sorensen_thorium_an_alternativ...](http://www.ted.com/talks/kirk_sorensen_thorium_an_alternative_nuclear_fuel)

------
spenrose
Two articles on why nuclear will never* scale up:

[http://www.carbontax.org/blogarchives/2013/11/21/why-
officia...](http://www.carbontax.org/blogarchives/2013/11/21/why-official-
nuke-plant-cost-estimates-are-like-campaign-promises/)

[http://www.forbes.com/sites/energysource/2014/02/20/why-
the-...](http://www.forbes.com/sites/energysource/2014/02/20/why-the-
economics-dont-favor-nuclear-power-in-america/)

* (again. It did reach real scale in post-WWII France among other places)

~~~
fnordfnordfnord
Komanoff doesn't know it but he is helping make the Thorium MSR case.
Proponents of the MSR are also critical of LWR economics.

------
nnq
I see this as the main takeaway from the article instead:

> One or two 233U bombs were tested in the Nevada desert during the 1950s and,
> perhaps ominously, another was detonated by India in the late 1990s. [...]
> intense gamma radiation 233U produces fries the triggering circuitry

...this only shows that military use _is possible!_ For someone less concerned
about safety and more concerned about having a nuclear weapon at all costs, it
might be even easier. That triggering circuitry is definitely a solvable
problem... brrrrrr

~~~
eleitl
Not just the proliferation resistance is a myth, but there are several others
making the round:
[http://www.whatisnuclear.com/articles/thorium_myths.html](http://www.whatisnuclear.com/articles/thorium_myths.html)

~~~
hga
Yeah, chemical separation + gun assembly warheads is a particularly bad path
to allow, side steps the two hardest current things required (non-chemical
uranium enrichment and implosion based warheads).

------
stratos13
I think thorium MSRs are the most promising of the GenIV designs. However, the
biggest engineering challenge with them is with the U-232 being produced.
U-232 decays into Thalium-208 and gives off very high energy radiation which
would kill anyone near it, as well as damage any electronics in the vicinity
(this is also why making bombs out of thorium are not as big a threat). But if
this can be overcome I think it'd be a great source of power.

------
eleitl
A few myths found:
[http://www.whatisnuclear.com/articles/thorium_myths.html](http://www.whatisnuclear.com/articles/thorium_myths.html)

------
willvarfar
Am I the only one who can't actually _read_ the article? All I get is a "sign-
up" floater :(

~~~
barrkel
I got it without (to my knowledge) overflowing any limits for any reasonable
time period.

Do a Google search for the headline and click on the article that way. Or
forge the 'Referer' header.

------
everyone
Brilliant fairly technical presentation on Thorium.

[http://www.youtube.com/watch?v=AHs2Ugxo7-8](http://www.youtube.com/watch?v=AHs2Ugxo7-8)

This more or less sold me on the idea years ago.

------
einrealist
What about the radioactive waste? All nuclear reactors produce waste (finally
when disassembled after the reactors' end of life). I find it strange to
search for more efficient reactor styles, while the waste problem is not
solved.

~~~
dragonshed
Most of the waste from traditional reactors is actually unspent fuel. Solid
fuel rods only allow for about 1-2% energy conversion before the amount of
transuranics and other contaminants built up and prevent safe operation.

The idea of the liquid fueled reactors is that you can easily change the fuel
composition, ideally constantly reprocessing the fuel of contaminates, while
letting the unburned fuel stay in place. This would drastically reduce the
amount of waste generated (by orders of magnitude), and the 'unburnable' waste
left over actually has some uses of its own (molybdenum 99 and bismuth 213).

~~~
einrealist
Most of the waste is actually not the fission product itself, but everything
else that is required to maintain the reactor aswell as the reactor itself.

------
politician
Ah, Thorium articles. Guaranteed views from nerds, a great way to discover a
cohort in your audience, and an easy template to follow (e.g. "it'd be so
great, but adoption is 10 years away").

(Don't vote me up for this either. Dismissive first posts are another HN
trope, so in this regard I'm as guilty as The Economist.)

~~~
Kroem3r
Pff. If 'molten salt' reactors are an inch closer in 10 years, I will eat my
hat. The idea is only slightly more appealing than having the reactor fly
around under it's own power.

What makes you think The Economist is interested in probing the nerdosphere?
Would Tesla, Apple, etc., be more effective? For sure, the '... adoption is 10
years away' thing is funny. Makes me reminisce for Popular Science.

If I were to guess; they are advertising where their technological sympathies
lie. It is more about managing their brand than probing an audience.

~~~
jff
> The idea is only slightly more appealing than having the reactor fly around
> under it's own power.

That _was_ a pretty fun one:
[http://en.wikipedia.org/wiki/Project_Pluto](http://en.wikipedia.org/wiki/Project_Pluto)

~~~
Turing_Machine
This was better:

[http://en.wikipedia.org/wiki/NERVA](http://en.wikipedia.org/wiki/NERVA)

If we hadn't canceled it we'd be colonizing the Solar System by now.

------
zebulom
The buzz for thorium reactors is made by people who want to sell thorium
reactors.

~~~
TeMPOraL
And repeated by those who don't want this civilization to end when we either
run out of fuel or break the ecosystem.

