
China boasts breakthrough in nuclear technology - bd_at_rivenhill
http://www.reuters.com/article/idUSTRE7020DB20110103
======
PaulHoule
You need more than a new reprocessing plant to significantly extend uranium
supplies, you also need a new kind of reactor.

The Light Water Reactor (currently in use worldwide) produces a small amount
of Plutonium while it operates. With reprocessing of both the U235 and Pu in
Uranium fuel, you can get 30% more energy per pound. That's nice, but it's
nothing like a fast reactor which can produce more Plutonium than it
consumes... With fast reactors, it's possible to burn not only U235, but U238,
which gives the 60x fold increase in energy mentioned in the articles.

Note that the nuclear waste that we've currently got cooling in dry cast
storage is mostly U238 with a little Pu and U235 in it. Reprocessed, the
current stock of spent fuel in the U.S. could power the country for at least a
century before we'd need to start mining Uranium again.

Yes, the technology isn't mature, but the price is enormous -- essentially
unlimited energy, since uranium can be extracted from seawater at a reasonable
price if we can burn the U238.

~~~
uvdiv
True. China did build a new fast test reactor last year:

[http://www.neimagazine.com/story.asp?sectionCode=132&sto...](http://www.neimagazine.com/story.asp?sectionCode=132&storyCode=2056921)

~~~
PaulHoule
I'd love to see some more details about that.

I get the impression that sodium cooled reactors with water as a working fluid
in the turbines are a non-starter today. There's not only the reactivity
problem, but also the fact that the steam turbines are H-U-G-E. I think
commercially workable sodium cooled reactors will use something like
supercritical CO2 as the working fluid, which can produce something that's
simultaneously safer and much much cheaper.

~~~
uvdiv
Not an engineer, but I don't think the sodium/water heat exchangers are a
fatal setback -- for one thing, there's an intermediate sodium loop between
the core sodium coolant and the turbine loop, so any sodium/water interaction*
isn't near the reactor core. I'm pretty sure all SFRs to date have had steam
turbines.

* euphemism

> _but also the fact that the steam turbines are H-U-G-E._

That's not enough of a setback to stop most power plants in the world from
using the Rankine cycle. You should ask an engineer why this is, I am not one.

------
ajscherer
The complete lack of any details may fly on Chinese Central Television and
Reuters.com, but I want more when I come to hacker news. What's next? "North
Korea boasts development of time machine!"

~~~
cdavid
This kind of claims has been heard in France as far as I can remember it. I
don't know how technologies differ between French technology (super-phenix)
and chinese ones, but I would be warry about the claims before seeing concrete
results: fast breeder super phenix was supposed to solve most issues with
civil nuclear usage, and it cost a fortune without producing electricity
anywhere near reasonable cost.

Thorium-based designs seem more realistic and useful, I wonder why this is not
investigated more: it is more common than uranium and produces less nuclear
waste than uranium-based designs. The US has a lot of it, Europe has a lot of
it so it makes sense for countries like France to look at it, etc...

~~~
uvdiv
I'd be wary of calling sodium fast reactors inferior on the basis of their
past performance. All SFRs ever built were essentially prototypes; all their
operating experience combined is less than what LWRs had in the 1960's. If
thorium reactors had fewer spectacular commercial failures (e.g. [1]), it's
largely because they had fewer commercial attempts.

(That's not to concede that SFR failures were entirely commercial -- political
obstruction was a large factor too. Both anti-nuclear opposition in general
(post-Three Mile Island and post-Chernobyl) as well as specific, extremely
misguided opposition to plutonium breeding. Argonne's IFR project was killed
for this second reason [2]).

> _Thorium-based designs seem more realistic and useful, I wonder why this is
> not investigated more: it is more common than uranium and produces less
> nuclear waste than uranium-based designs._

There's no meaningful distinction between FBRs and thorium reactors in fuel
supply -- both have theoretically thousands of years of potential, so that
it's silly to call this a factor. Nor is there a significant difference in
waste production. (Though if I remember right, some minor actinides can only
be efficiently destroyed by fast neutrons. This isn't an important difference;
MAs are a small component, so you can augment a thermal-reactor fuel cycle
with dedicated "waste burners" (e.g. [3] [4]) and still have a mostly-thorium
fuel cycle).

[1] <http://en.wikipedia.org/wiki/THTR-300>

[2]
[http://www.pbs.org/wgbh/pages/frontline/shows/reaction/inter...](http://www.pbs.org/wgbh/pages/frontline/shows/reaction/interviews/oleary.html)

[3] [http://energyfromthorium.com/2009/11/11/lftr-and-msrs-
achiev...](http://energyfromthorium.com/2009/11/11/lftr-and-msrs-achieve-the-
doe-nes-goals/)

[4] <http://www.oecd-nea.org/ndd/reports/2002/nea3109.html>

~~~
cdavid
I did not call anything inferior - I don't know anything about nuclear
technologies, so I could not make any judgement of that nature. My argument
was that fast breeder is nothing new in principle, and the claims as stated in
the article are the same as the ones we heard in france when speaking about
super phenix.

I don't think super phenix can be considered as a prototype: as a target
production power of > 1000 MW, it is closer to conventional, commercial
reactors (those are theoretical numbers, which were never reached, let alone
sustained).

Thorium-based reactors are more mature than FBR as far as I understand, and my
argument about thorium was against conventional reactors as stated, not fast
breeders. As for supply, besides amount, the location also matters a lot.
There is thorium in Europe, but little uranium as far I understand, which
matters quite a bit.

~~~
uvdiv
It's not the size, it's the maturity. As you correctly criticize, Superphenix
was non-functional much of the time: there were major engineering issues which
hadn't been solved beforehand. This is the character of a prototype.

> _Thorium-based reactors are more mature than FBR as far as I understand_

Thorium reactors are even less mature than FBRs. Although that's a very loose
category, you should distinguish between the extremely different reactor types
which burn thorium, such as high temperature gas-cooled reactors (including
pebble beds), which were the only commercial thorium reactors (for a short
time); and the theoretical molten salt reactors, which unlike HTGRs are
breeder reactors. For added confusion, some commercial (both LWR and HWR)
reactors can run _partially_ on thorium, but are not self-sufficient without
uranium or plutonium fuel.

------
lutorm
"the re-use of irradiated fuel and is able to boost the usage rate of uranium
materials at nuclear plants by 60 folds."

Say again? That means you use _more_ uranium...

~~~
pjscott
They're trying to use more of the uranium in the fuel, by extracting left-over
U-235 and bred Pu-239 to use as fuel again. The U-238 can also be used in
breeder reactors, once we get those going. It's recycling! Sort of.

~~~
lutorm
Yeah, but that better _lower_ the usage rate, otherwise it won't last
longer...

------
rorrr
> "With the new technology, China's existing detected uranium resources can be
> used for 3,000 years,"

Another failure to consider that energy demands grow pretty much
exponentially.

~~~
ryanwaggoner
It really doesn't...

[http://en.wikipedia.org/wiki/File:World_Energy_consumption.p...](http://en.wikipedia.org/wiki/File:World_Energy_consumption.png)

And that's ignoring the fact that there were less than 3 billion people in the
world in 1965.

