
World’s First Thorium Reactor Designed - sasoon
http://www.itheo.org/articles/world%E2%80%99s-first-thorium-reactor-designed
======
Gravityloss
Note that this very different to the molten salt LFTR design. With solid fuel
it is very hard to prevent protactinium capturing neutrons, which means
problems for breeding and waste and probably operational constraints as well.
The LFTR is such a beautiful consistent design but it is very different from
ordinary reactors.

Also the title is inaccurate as different thorium reactors have been designed,
built and operated. See MSRE and THTR-300 for example.

~~~
warfangle
The big problem with a molten salt LFTR is the materials necessary for the
plumbing. Any metal will become brittle as it is exposed to the radiation
emitted from the reactor core. And manufacturing ceramics into the precision
pieces called for is not a solved problem.

LFTR designs are fantastic, amazing, and solve a lot of problems. There is a
lot of materials science to be done to make them viable, though.

~~~
JohnHaugeland
You're confusing issues from pressurized reactors with LFTRs. The reason
manufacturing ceramics for pressurized reactors is hard is the pressure and
size involved. LFTR can be run at normal pressure at small scale; you can use
a kiln as the pressure vessel if you want to.

Also, no, not any metal gets brittle; inconel and hastelloy handle radiation
quite well for decades at a time, as does good old fashioned nickel. Beyond
that, most reactor pressure vessels are a layer of metal then a layer of
something that's really good at radiation, then the real pressure vessel, so
that the interior layer's brittleness isn't very important.

We built and ran LFTRs commercially in the 1950s in New York State and
Pennsylvania, before computers became a commercially realistic thing. They
provided our grandparents no significant technical challenge.

The _actual_ big problem with LFTR is primarily regulatory. The design hasn't
been vetted to modern safety standards, which costs hundreds of millions of
dollars, and the entities who are nuclear-aware and have that kind of money to
throw around tend to be the existing nuclear companies, who can't switch to
any other technology because they're deep in the Gilette Razor model, and
anything that took out their existing fuel contracts would immediately
bankrupt them.

There is /zero/ materials science needed to make a LFTR. I don't know where
you got that idea. They're substantially easier than what we make today. The
average auto body shop can pull it off.

~~~
warfangle
>You're confusing issues from pressurized reactors with LFTRs.

Nope, pretty sure I'm not. I'm well aware that LFTRs run at low (even sub-
atmosphere) pressures.

>We built and ran LFTRs commercially in the 1950s in New York State and
Pennsylvania

We never ran LFTRs commercially. If you know otherwise, please cite. I only
know of two experimental reactors at the Oak Ridge facility: the Aircraft
Reactor Experiment and the Molten-Salt Reactor Experiment.

> I don't know where you got that idea.

I got that idea from some pretty simple facts about nickel alloys (like
Hastelloy N) under neutron bombardment.

When you bombard nickel with neutrons, you produce helium. When the helium
builds up irregularly, the alloy becomes brittle. You can dope Hastelloy N
with titanium or niobium to even out the distribution of helium deposits (this
is what ORNL did) but that brings the maximum temperature down to 650C.

As well, tellurium (one of the fission products of a LFTR reactor) corrodes
the grain boundaries of Hastelloy N. You can reduce this effect by doping it
with niobium and keeping the UF4/UF3 ratio to less than 60.

You have to trade off lower temperatures with whether or not you want to deal
with beryllium toxicity. You can replace BeF2 with a eutectic lithium
fluoride/thorium fluoride composition, but that requires an increased
temperature of the reactor salts. There are other problems with using
beryllium, though - it produces lithium-6, which is a strong neutron poison.

You also have to filter out noble element deposits, because they don't form
fluorides.

There are also serious design challenges with modifying current turbines to
work with supercritical CO2 or helium. You can use supercritical steam
instead, but it isn't nearly as efficient.

You also have to worry about tritium diffusion. It's small enough that it
leaks through the heat exchangers.

There are issues with the rapid expansion/contraction the graphite moderator,
but some are working on graphite pebble designs.

Once you throw the corrosive salts, strange reaction byproducts, and neutron
bombardment into the mix, I highly doubt that 'the average body shop' could
pull off the fabrication of a LFTR style molten salt reactor that could run
safely for longer than a week.

~~~
Gravityloss
I was surprised to hear from GE that a CO2 working fluid power plant using
turbine waste heat is a thing nowadays. They have a contractor, Echogen, who
provides that part.

[http://www.cospp.com/articles/print/volume-14/issue-01/featu...](http://www.cospp.com/articles/print/volume-14/issue-01/features/supercritical-
co2-refines-cogeneration.html)

[http://www.echogen.com/documents/why-sco2-can-displace-
steam...](http://www.echogen.com/documents/why-sco2-can-displace-steam.pdf)

In ships, when fuel costs just keep on rising, that starts making sense.
(There are other reasons why it might not be good though.) On land power
plants, it might make natural gas electricity more competitive against coal
with this better efficiency.

Though I don't see the keyword supercritical on the Echogen site yet...

~~~
warfangle
Oh neat, I didn't know about that either.

------
spenrose
The problem with nuclear power is not the primary fuel; it's the economics,
especially the economics of big engineering:

[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/)

~~~
DennisP
From the first link: "In those decades parts of plants were built, ripped out
and rebuilt because of design and regulatory problems, leading to ruinous
costs."

I've read about this before. Companies start building plants based on existing
regulations. Along the way, the NRC changes the regulations, requiring tear-
down and rebuilding. Meanwhile interest on the loan keeps building up. Add
further delays due to political resistance and it's no wonder costs escalate.

It's not just the economics of big engineering causing the problem here. I
think matters have improved somewhat in the U.S., but it's still going to be
interesting to see how AP-1000 costs in the U.S. compare to those in China.

Incidentally, there are some arguments that liquid thorium reactors, and some
other GenIV designs, could have significantly lower capital costs than
conventional reactors. A big reason for that is that the basic physics of fuel
and coolant provides substantial passive safety, rather than relying on lots
of redundant active systems.

~~~
spenrose
The interweaving of complex shifting regulations with the economics of $B
plants that take decades to build and involve tremendous amounts of radiation
and energy is not some random coincidence, nor is the absence of Buffets and
Icahns lining up to make a killing on the erstwhile Future of Clean Energy (as
opposed to wind and solar). If thorium can't solve the political economy
problems, then thorium is dead. A small loud group of techies yelling "don't
you get it?!" and upvoting thorium posts on HN is just part of the ??? between
underpants and the profit we will never see.

~~~
DennisP
As I implied above, it's a problem in particular jurisdictions, not
necessarily everywhere. China for one is aggressively pro-nuclear. If thorium
reactors are everything their advocates think they are, countries that throw
too many obstacles in their path will disadvantage their economies.

Aside from that, nuclear reactors don't necessarily have to be gigawatt-size.
Even in the U.S., smaller reactors are starting to make some regulatory
headway.

But even conventional 1GW reactors don't have to take decades to build.
China's first AP-1000s at Sanmen are being finished up this year and next for
a construction time of five years.

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

[http://www.world-nuclear-news.org/NN-First-Haiyang-
AP1000-ta...](http://www.world-nuclear-news.org/NN-First-Haiyang-AP1000-takes-
shape-1103144.html)

~~~
spenrose
China matters, and it can bypass procedural democracy. Large, slow-to-deploy
nuclear still has to compete with quick-deploying, cost-decreasing solar and
wind (and serious efficiency measures) while it is on the costs-rising-due-to-
learning part of its rollout curve. Procedural democracy will not allow new
nuclear of any kind in most of the rich democracies. We need everything, but
solar PV, wind, and efficiency are the low-hanging fruit.

~~~
DennisP
I agree we should pursue it all. Solar is rolling out pretty quickly right
now. It's later, when we want to get past using fossil to compensate for
intermittency, that nuclear will be especially important...and it would be
good to be past that learning curve by then.

------
prestadige
This is great news. I've read about so many great nuclear projects in the past
few years. Three thorium initiatives in China, India and Norway. ITER in
Europe. Bussard Electrostatic Fusion. Travelling Wave Reactors. General
Fusion's Steam Hammer Design. And there are many more. So it looks like an
increasingly bad bet to say that they will _all_ fail. Which is good, because
we're going to need lots of energy in the future.

------
linohh
I went to school next to THTR-300 which was built from 1971 on and is now
defunct thanks to incompetence and huge failures in crisis management.

[http://en.wikipedia.org/wiki/THTR-300](http://en.wikipedia.org/wiki/THTR-300)

~~~
madaxe_again
That, and incredibly unfortunate timing. I dare say that had the incident
happened two weeks earlier, or several years later, there would have been no
uproar - but for it to happen several days after Chernobyl, and for them to
then try to cover it up... couldn't be worse.

------
stox
Oak Ridge had a Thorium reactor in 1965. This is not the first.

~~~
VLM
The situation is actually even worse, here's a wikipedia link to a list of
fifteen Th fueled reactors:

[http://en.wikipedia.org/wiki/Thorium_fuel_cycle#List_of_thor...](http://en.wikipedia.org/wiki/Thorium_fuel_cycle#List_of_thorium-
fueled_reactors)

~~~
mdellabitta
I just went past one on the train to work. They're everywhere!

------
JohnHaugeland
On what planet is this the world's first thorium reactor? We had running
thorium reactors in the 1950s.

------
acd
Fast breeder Thorium reactors and electric cars to the people! Cheap energy
and clean cars.

------
msandford
I'm really glad to see that the concept is starting to take off.

It makes me sad that it's not happening in the US. If some folks in the
government and business don't get their heads out of their asses a growth
industry is going to bypass us entirely.

~~~
cstross
Note that you can breed U-233 from thorium and use that in nuclear weapons.
The critical mass of U-233 is about 50% higher than Pu-239 but otherwise it's
usable in implosion-type bomb designs; the main hazard is the presence of
U-232 as a contaminant (which is a high level gamma emitter and makes it
dangerous to work with) -- the real question is how they plan to reduce the
U-232 contamination level enough to make weapons-safe U-233.

As India is already a nuclear weapons power, this has no immediate
proliferation implications ... but moving a nation of a billion-plus people
onto an energy cycle that produces weaponizable material as a by-product
_might_ be considered unwise by some. Cf. concerns in the 1970s and 1980s
about the implications of running a "plutonium cycle" fast breeder energy
ecosystem.

~~~
msandford
If everyone in the world had enough energy to live a developed-world middle-
class lifestyle -- and with thorium reactors this might be feasible -- might
that not eliminate one of the driving forces behind global conflict?

I'm not saying it's a slam-dunk win for sure.

But I have noticed a lot of general apathy and aversion to violence in the
developed world largely because people are just too busy living their lives;
they have a lot to lose.

> the real question is how they plan to reduce the U-232 contamination level
> enough to make weapons-safe U-233

I'm not convinced that anyone has this goal in mind. Maybe they just want to
provide power to their countrymen and continue to lift India out of poverty.
There might be nothing nefarious about this, unless you consider poor people
getting less poor to be a problem.

~~~
Rapzid
In certain parts of the world, maybe. In other parts differences in religion
is the driving force behind conflict..

~~~
madaxe_again
Disagree. Religion is the vehicle. Inequality is the driver.

~~~
Tloewald
There were/are religious conflicts in communities where it's impossible to
tell the belligerents apart -- ethnically, economically, you name it.

"For every complex problem there is an answer that is clear, simple, and
wrong."

Inequality is definitely a contributing factor, perhaps even _the_
contributing factor, but don't count out religion.

~~~
Jach
Inequality is the wrong diagnosis. As msandford pointed out, it's more likely
to be a minimum standard of living issue and having enough to lose. If
inequality was a main factor, you would expect Pakistan to have similar crime
rates as Sweden, when in reality they're not even close. (PG has an essay on
inequality being a boon to a nation's economy:
[http://www.paulgraham.com/inequality.html](http://www.paulgraham.com/inequality.html))
You could also look at the religiosity of a country, but the trend there is
that lower standards of living correlate with higher religiosity.
([http://www.gallup.com/poll/142727/religiosity-highest-
world-...](http://www.gallup.com/poll/142727/religiosity-highest-world-
poorest-nations.aspx)) I'm more inclined to think the causation goes from low
standard of living --> religiosity rather than the other way around, given the
United States. However there could be other deeper factors that give rise to a
low standard of living, such as a nation's average IQ -- you're not going to
see a nation with average IQ of 70 outperform let alone match a nation with
average IQ of 100 in terms of standard of living.

~~~
Tloewald
Good point regarding inequality vs absolute standard of living, but you're
also talking about inequality within national boundaries. A good bit of the
resentment of the Muslim world towards the West stems from perceived injustice
and power imbalance on a regional or global scale.

There is also a big difference between inequality as a ratio of rich to poor,
and actual conditions. The poor in Sweden are better off relative to the rich
than the poor in Pakistan.

------
Aardwolf
Nice specs!

Where does the Thorium come from and how abundant is it?

~~~
orbifold
Roughly 3-4 times as abundant as Uranium, according to [http://www-
pub.iaea.org/MTCD/publications/PDF/TE_1450_web.pd...](http://www-
pub.iaea.org/MTCD/publications/PDF/TE_1450_web.pdf). To give you an idea on
how much energy could be produced with this: A rough estimate shows that if
all our current electric energy demand would be satisfied with Uranium, the
reserves would run out in roughly 10 years. See
[http://johncarlosbaez.wordpress.com/2010/09/03/how-long-
woul...](http://johncarlosbaez.wordpress.com/2010/09/03/how-long-would-
uranium-last/).

~~~
Tuna-Fish
> rough estimate shows that if all our current electric energy demand would be
> satisfied with Uranium, the reserves would run out in roughly 10 years.

While strictly correct, this is extremely misleading. Current resources would
be exhausted in a decade, but resources are defined as the known deposits
extractable under current market prices. Should we actually start using a lot
of uranium, the price would spike, which would lead to a lot more deposits
becoming economically available. This has almost no effect on the cost of
nuclear power, as the cost of the raw uranium isn't a large part of the cost
of producing power.

The end game there is when the price rises sufficiently for extraction from
seawater becoming profitable. The world's seas have ~1000 times more uranium
than conventional ground-based resources.

Nuclear fuels will not run out in this millennium.

~~~
venomsnake
How about energy return on energy investment. You have to vaporize a lot of
water (of course you will have all those gold, iron, rare metals "waste" which
will help the economic case).

~~~
maxerickson
Research has focused on other methods:

[http://en.wikipedia.org/wiki/Uranium_mining#Recovery_from_se...](http://en.wikipedia.org/wiki/Uranium_mining#Recovery_from_seawater)

