Energy From Thorium Discussion Forum

It is currently Feb 25, 2018 10:36 pm

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 186 posts ]  Go to page 1, 2, 3, 4, 5 ... 13  Next
Author Message
PostPosted: Jan 20, 2007 11:08 pm 
Offline
User avatar

Joined: Nov 30, 2006 9:18 pm
Posts: 1954
Location: Montreal
Back in the 90's, before Edward Teller passed away, he and a few of his colleagues at LLNL came up with this interesting concept.
What I found so interesting about it, is the "burn wave" idea: it relates to another topic I have been interested in the past, that of the so-called geo-reactor (see http://www.nuclearplanet.com )

I was surprised to find that these old links, stored away in the memory of my computer, are still not broken :!:

Quote:
http://www-phys.llnl.gov/adv_energy_src/
Completely Automated Nuclear Reactors for Long-Term Operation II: Toward A Concept-Level Point-Design Of A High-Temperature, Gas-Cooled Central Power Station System
UCRL-JC-122708 Pt 2 PREPRINT
Edward Teller
Muriel Y. 'Yuki' Ishikawa
Lowell Wood

Stanford University, Stanford, CA 94305-6010
Roderick Hyde and John Nuckolls
University of California Lawrence Livermore National Laboratory, Livermore, CA 94551-0808

This paper was prepared for invited presentation at the plenary session of the 1996 International Conference on Emerging Nuclear Energy Systems (ICENES'96), Obninsk, Russian Federation 24-28 June 1996, and is the full version, an abbreviated form of which will appear in the conference proceedings.
<snip>

Our current reference-design reactor contains a cylindrical core comprised of a small nuclear ignitor and a much larger nuclear burnwave-propagating region. The latter contains natural thorium or (possibly depleted) uranium fuel, and functions on the general principle of fast breeding. The entire core is surrounded by a neutron reflector and a radiation shield. Uniform temperature throughout the core is maintained by a large multiplicity of thermostating modules which, through the action of simple automatic controls transporting isotopically-enriched lithium when the local material temperature rises into the regime corresponding to a coolant-gas-temperature design-value of ~1000 K, depress the local neutron flux and thereby reduce the local power production. Triply-redundant primary means of transporting heat up to the generating station are provided, and entirely independent, triply-redundant energy-dumping means are included in this design to passively transport afterheat out of the core in the event of a loss-of-coolant accident or after the end-of-operational-life.

Image
<snip>

Such a reactor must be a breeder, for reasons of efficient nuclear fuel utilization and of minimization of requirements for isotopic enrichment. It must be a fast breeder because the high absorption cross-section of fission products for thermal neutrons does not permit the utilization of more than about 1% of thorium (or of the more abundant uranium isotope, U238, in uranium-fueled versions), without removal of fission products.
<snip>

At the commencement of the reactor's operational life, the centrally-positioned nuclear ignitor module is driven critical by one-time removal of neutronic poison and, through concurrent nuclear fission and high-gain breeding actions, commences to launch a nuclear deflagration wave into the adjacent unenriched fuel. This wave first diverges radially from the centrally positioned, on-axis nuclear ignitor until portions of it reach the outer edge of the cylindrical fuel mass, where it is resolved into two oppositely-directed, axially-propagating waves. One such wave moves toward each of the two ends of the cylindrical core at a (exceedingly low peak) speed determined at all times by the instantaneous thermal power demand on the reactor (and upper-bounded by the leisurely beta-decay of Pa233, the rate-limiting step in Th232-U233 breeding).
<snip>

Fuel moderately enriched in fissile material is generated behind each of the two wave-fronts. These two increasing masses of enriched fuel then continue to burn, until fission product accumulation and fertile isotopic depletion (at a 50% core-averaged fuel burn-up) finally drives the core's neutronic reactivity negative. Figure 5 illustrates typical conditions ahead of, within, and behind this pair of nuclear deflagration waves, and Appendix B discusses core nucleonics in more detail.
http://www-phys.llnl.gov/adv_energy_src/ICENES96.html#AppendixB

Image
<snip>


Top
 Profile  
 
PostPosted: May 09, 2008 4:27 am 
Offline
User avatar

Joined: Dec 04, 2006 8:41 am
Posts: 166
Location: Espoo, Finland
On a breeder reactor with various fuels. Seems to be a never refuel-type. I don't know what's actually new here. From a Slashdot article about the patent company...


Top
 Profile  
 
PostPosted: May 09, 2008 11:35 am 
Offline
User avatar

Joined: Apr 21, 2007 1:42 am
Posts: 90
Location: Silicon Valley, CA
meiza wrote:
On a breeder reactor with various fuels. Seems to be a never refuel-type. I don't know what's actually new here. From a Slashdot article about the patent company...


Here's a PDF with some of the same authors, going back to 1997:

Problem-Free Nuclear Power and Global Change

22nd International Symposium on Planetary Emergencies
Erice, Italy
August 20-23, 1997

E. Teller, L. Wood, J. Nuckolls, M. Ishikawa, R. Hyde

http://www.osti.gov/bridge/servlets/purl/614877-A54YYF/webviewable/614877.pdf


Top
 Profile  
 
PostPosted: May 10, 2008 6:07 am 
Offline

Joined: Dec 26, 2007 11:45 am
Posts: 191
meiza wrote:
On a breeder reactor with various fuels. Seems to be a never refuel-type. I don't know what's actually new here. From a Slashdot article about the patent company...


Quote:
“We have thirty guys working on it,” he went on. “I have more people doing cutting-edge nuclear work than General Electric. We’re looking for someone to partner with us, because this is a huge undertaking. We took out an ad in Nuclear News, which is the big trade journal. It looks like something from The Onion: ‘Intellectual Ventures interested in nuclear-core designer and fission specialist.’

http://www.newyorker.com/reporting/2008/05/12/080512fa_fact_gladwell?currentPage=all


Well, that is supposedly what's new about it. Having a serious team of people funded and working on it.

But I think they may be too obsessed with making this thing 100% hands-off.


Top
 Profile  
 
PostPosted: May 15, 2008 4:32 pm 
Offline

Joined: Dec 09, 2007 3:41 pm
Posts: 77
meiza wrote:
On a breeder reactor with various fuels. Seems to be a never refuel-type. I don't know what's actually new here. From a Slashdot article about the patent company...


Very interesting article! I love the nuclear candle ever since I first heard of it. But I dont think I have ever read a review article written in a more pompous language :?:


Top
 Profile  
 
PostPosted: May 15, 2008 4:55 pm 
Offline
User avatar

Joined: Nov 30, 2006 3:30 pm
Posts: 3431
Location: Alabama
I've got the paper downloaded and reading it now.
Attachment:
myhrvoldConcept.pdf [1.17 MiB]
Downloaded 1293 times


Top
 Profile  
 
PostPosted: May 15, 2008 6:17 pm 
Offline

Joined: Apr 24, 2008 4:54 am
Posts: 491
Location: Columbia, SC
Owen T wrote:
Having a serious team of people funded and working on it.


These people are a bunch of crooks. You guys should really look this company up. They appear to be nothing more than a bunch of patent vultures. They make their money by filing vague patents, then suing to enforce them on unsuspecting new innovators. They do not actually develop anything all the way to market. They are really bad news.

This might be very bad news for Thorium reactors if they try and process a bunch of patents on the various parts of it. It could totally shut down development on this. Even if a lot of it is prior art, that doesn't stop them and the current patent system is almost useless to help stop it.


Top
 Profile  
 
PostPosted: May 15, 2008 10:59 pm 
Offline
User avatar

Joined: Nov 30, 2006 3:30 pm
Posts: 3431
Location: Alabama
USPWR_RO wrote:
This might be very bad news for Thorium reactors if they try and process a bunch of patents on the various parts of it. It could totally shut down development on this. Even if a lot of it is prior art, that doesn't stop them and the current patent system is almost useless to help stop it.


Wow...I'm feeling a lot better about the fact that their work has almost nothing in common with ours now!


Top
 Profile  
 
PostPosted: May 15, 2008 11:58 pm 
Offline

Joined: Apr 24, 2008 4:54 am
Posts: 491
Location: Columbia, SC
Just beware...these 5 guys are leeches in the worst sense of the word.


Top
 Profile  
 
PostPosted: May 17, 2008 7:12 pm 
Offline
User avatar

Joined: Nov 30, 2006 3:30 pm
Posts: 3431
Location: Alabama
I kept reading through this and I was pretty unimpressed. I'm not sure if the paper was simply a rehashed version of the patent application but I strongly suspect that it was, because everything was written a mile wide and an inch deep.

In short they've got a concept that sounds similar to the Toshiba 4S concept, where you burn your way down the length of some mass of fertile material. It's a fast spectrum reactor, because they say they can only get the kinds of breeding ratios they're looking for with a fast spectrum, but then later in the paper they eschew reprocessing and claim that they're going to bury the reactor on site in its cask.

In another part they say that the reactor doesn't need any fuel enrichment, but then later on they say that the reactor will have to be started with some fissile source or from spallation neutrons from a particle accelerator. So, if they have a fissile source, then they need enrichment, right? (or some kind of fissile recovery from another generation of the reactor) If they use "electrobreeding" then they need to show how the particle accelerator beam gets right now in the middle of the core and how long they're going to have to run the thing before it will go critical on its own. I seem to recall from previous discussions on this subject that the "electrobreeding" approach took forever and was extremely expensive.

They're also really vague about the primary heat transport out of the core. They say they favor high-pressure helium--so what, now we've got a big gas-cooled fast reactor? They also say they're not sure they want to use a Brayton cycle, Rankine cycle, or some hybrid. Sounds like they want to cover all their bases in the patent application.

Really, the whole thing reads to me like it was written by folks who haven't thought a great deal about core neutronics, thermal-hydralics and their coupling to core neutronics, and the influence of power conversion and heat rejection on the overall design.


Top
 Profile  
 
PostPosted: Jul 21, 2008 4:50 pm 
Offline
User avatar

Joined: Nov 30, 2006 3:30 pm
Posts: 3431
Location: Alabama
More on Nathan Myhrvold's adventures (when he's not working on thorium reactors):

Eating Polar Bears Is Okay in Greenland


Top
 Profile  
 
 Post subject: Travelling wave reactor
PostPosted: Sep 20, 2008 1:53 pm 
Offline
User avatar

Joined: Sep 10, 2008 7:40 pm
Posts: 299
Dan Yurman tipped me off on the effort by Microsoft millionaire Nathan Mhyrvold's Intellectual Ventures investment (20 nuclear engineers) in technology that can use thorium as a fuel.

http://online.wsj.com/article/SB122161127802345821.html

http://djysrv.blogspot.com/2008/09/micr ... clear.html

http://en.wikipedia.org/wiki/Traveling_wave_reactor

http://www.inspi.ufl.edu/icapp08/progra ... s/8319.pdf Novel Reactor Designs


Top
 Profile  
 
PostPosted: Sep 20, 2008 5:56 pm 
Offline

Joined: Dec 14, 2006 1:01 pm
Posts: 380
I think the traveling wave reactor (TWR) is an obviously bad idea in policy terms.
1. It does bad things to energy infrastructure.
a) Each installation will work a long time.
b) Each installtion will then fail, either mechanically, or by running out of fuel.
c) Maintenance infrastructure will then not be available, because it has not been needed.
d) People dependent on the reactor will then have a terrible problem, compounded by a
lack of infrastructure to solve it.
e) If society depends on TWRs, society may enter a new dark age.
2. It will destroy nuclear R & D, and thus any likelihood of later advances.
e) a) & c) will reduce the need for nuclear education.
f) Nuclear enginers will become even more rare on the ground.
g) So, nuclear licensing will become even more ossified. (If that's possible!)
h) So, 2.
3. Each installtion will have a lot of fuel, and be very expensive. (Unless it's thorium)
j) Therefore, it is an -elitist- solution to the energy problem. It strongly implies
that its builders do not want to compete in an international energy market.
4. The business model is based on fear of future energy costs, or future antinuclear
biases. Since life improves over time, the device is irrational.


Top
 Profile  
 
PostPosted: Sep 20, 2008 9:11 pm 
Offline
User avatar

Joined: Oct 01, 2007 9:07 pm
Posts: 291
Dan's board:
http://djysrv.blogspot.com/2008/09/micr ... clear.html

These guys are putting real money into this. Any way we could contact them and hook them up with the LFTR design?

DAvid

_________________
David


Dr. Isaac Asimov:
"The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but 'That's funny ...'"


Top
 Profile  
 
 Post subject: Nuclear Microsoft
PostPosted: Feb 02, 2009 6:25 pm 
Offline

Joined: Dec 18, 2007 6:39 pm
Posts: 90
Location: CA
Does anybody know more about this?
http://www.greentechmedia.com/articles/ex-microsoft-scientist-crafts-nuclear-reactor-startup-5627.html

According to this:
Quote:
The reactors will ideally vary in size from a few megawatts, big enough to power industrial sites or small cities, to large multi-gigawatt reactors that can power a major city. Terrapower is also looking at thorium reactors, which do not release plutonium as a byproduct. That would further reduce any risks associated with nuclear.


Emphasis mine.

Should of interrest to people on this site.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 186 posts ]  Go to page 1, 2, 3, 4, 5 ... 13  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group