[ RadSafe ] Thorium nuclear fuel cycle
John R Johnson
idias at interchange.ubc.ca
Wed Nov 18 17:34:40 CST 2009
George and Mike
I agree with your comments on using U-233 in a nuclear bomb, but a major
factor in terrorists strategy is the "scare tactic", and "dirty bombs"can
scare people even if the explosive material is TNT.
If it spreads U-233 and other radioactivity in a city street, I would not go
shopping there.
John
***************
John R Johnson, PhD
CEO, IDIAS, Inc.
4535 West 9th Ave
604-676-3556
Vancouver, B. C.
V6R 2E2, Canada
idias at interchange.ubc.ca
----- Original Message -----
From: "George Stanford" <gstanford at aya.yale.edu>
To: "Brennan, Mike (DOH)" <Mike.Brennan at DOH.WA.GOV>
Cc: <radsafe at radlab.nl>
Sent: Wednesday, November 18, 2009 2:46 PM
Subject: RE: [ RadSafe ] Thorium nuclear fuel cycle
> Mike:
> Thanks for the kind words.
> In my opinion, the worry over terrorists making A-bombs
> from such materials is way overblown -- it takes too much
> time and technical sophistication. .Just the preliminary task,
> extracting U-233 from used fuel, would be far beyond a terrorist
> group's capabilities. They'd have to live long enough to finish
> the job, and they'd be sacrificing their best and brightest.
> The main concern is national subversion of a technical
> base to embark on a surreptitious weapons program (think
> Iran). That's why international oversight of enrichment and
> fuel-processing facilities is so important. Without access
> to one or the other of those, a nation cannot make weapons,
> no matter how many reactors it has.
> -- George
>
> ~~~~~~~~~~~~~~~~~~~~~~~~
>
> At 03:52 PM 11/18/2009, Brennan, Mike (DOH) wrote:
> Hi, George.
>
> I think this is a good and worthy letter. I also think you are perhaps
> the perfect person for it to come from. The only additional point I
> might make is that in addition to the scenario for producing clean
> U-233, one could separate out the uranium from the fuel, and just not
> worry about the U-232. The extra activity is only a problem if you want
> the people making your bomb to survive, and perhaps if you are looking
> for optimal energy release (I don't know how U-232 would affect the
> neutron economy of a potential weapon, and really don't care enough to
> research it). If sacrificing your own people is acceptable, and if the
> bomb is more for PR than actual destruction, then contaminated U-233 is
> probably good enough.
>
> -----Original Message-----
> From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
> Behalf Of George Stanford
> Sent: Tuesday, November 17, 2009 2:33 PM
> To: radsafe at radlab.nl
> Subject: RE: [ RadSafe ] Thorium nuclear fuel cycle
>
> All:
>
> To try to put the thorium issue into some sort of perspective,
> I am sending the the message below to the editor of Chemical
> and Engineering News
>
> Apologies to those who are getting this message more than
> once.
>
> -- George
>
> * * * *
>
> To: edit.cen at acs.org
> Subject: Reintroducing Thorium
>
> To the Editor
> Chemical and Engineering News
>
> In his interesting article "Reintroducing Thorium" (Nov. 16),
> Mitch Jacoby has been a little too uncritical in passing along the
> rosy opinions of the thorium enthusiasts. Here are some of the
> not-so-fine points his sources failed to tell him about.
>
> The article: "At no point in the thorium cycle, from mining
> thorium minerals to preparing and 'burning' reactor fuel to managing
> the waste, can fuel or waste products be converted into nuclear bomb
> materials. Unlike uranium, thorium is nuclear-proliferation proof."
>
> Reality: That is just plain wrong, for at least three reasons:
>
> - First, while a thorium reactor can indeed be operated in a
> break-even mode (producing as much fissile fuel as it consumes), it
> has limited breeding potential, so each new one must be primed with
> fissile from elsewhere -- meaning either plutonium from today's
> reactors or enriched uranium. Thus at least one and maybe both of
> the technologies that can separate weapons materials would continue
> to be needed as long as the thorium fleet continued to grow.
>
> - Second, any kind of reactor can be used to create weapons-quality
> plutonium by irradiating special uranium-containing fuel elements for
> short periods and then separating the resulting Pu-239. Thorium
> reactors are no exception.
>
> - Third, isotopically pure U-233 is a good bomb material. Some
> thorium enthusiasts like to point out that the U-233 is usually
> contaminated with U-232, rendering it too radioactive to make bombs
> with. However, it is quite feasible to use chemical means to
> separate the 27-day Pa-233 from the fuel, and then let it decay into
> isotopically pure U-233. In fact, that very process is part of some
> proposed thorium fuel cycles.
>
> In other words, for assurance that a nuclear power program is
> not being subverted, there must be effective international oversight
> of all enrichment and fuel-processing activities, regardless of
> reactor type. The reality is that the thorium cycle has no
> significant proliferation advantage over any other nuclear fuel cycle.
>
> The article: "For example, [thorium] is roughly four times more
> abundant than uranium."
>
> Reality: True (probably) but irrelevant. When used in fast
> reactors, uranium itself is inexhaustible .
>
> The article: "Thorium . . . does not need to undergo a costly
> and complex enrichment process to render it usable in a nuclear
> reactor."
>
> Reality: True but misleading. As observed above, a source of
> U-235 or Pu-239 would continue to be needed as long as new thorium
> reactors continued to come on line. Since the supply of plutonium is
> finite, enrichment of uranium would probably continue.
>
> The article: "Proponents also point out that although waste
> products from thorium usage are radioactive, radiotoxicity persists
> for just tens of years rather than thousands of years as uranium
> waste does. . . .
> "David LeBlanc, a staff physicist at Carleton University, in
> Ottawa, and a nuclear reactor specialist, points out several
> safety-related differences between LFTRs and today's commercial
> reactors. . . ."
>
> Reality: Both of those statements wrongly assume that thorium
> reactors would be in competition with thermal reactors (the kind that
> are in use today). But thorium technology is far from mature. As
> Mr. Jacoby reports, "Several attendees at the Washington conference
> acknowledged that an enormous investment of time, effort, and money
> would be required before any new type of nuclear reactor could be
> licensed for commercial operation." Thus the comparison that matters
> is not with today's commercial reactors, but with candidate
> "Generation IV" reactors. Of the latter, one of the leading
> contenders is the metal-fueled, sodium-cooled fast-reactor system
> known as the IFR (Integral Fast Reactor), which is not mentioned in
> the article but has very similar advantages over today's
> reactors. IFR technology is now so close to maturity that General
> Electric is prepared to do a commercial demonstration as soon as seed
> money and regulatory approval materialize.
>
> * * * *
>
> While the thorium cycle offers a clean, feasible, and possibly
> economical way to generate electricity, it is farther in the future
> than its main competitor, the IFR. Continued development of the
> thorium cycle would not be unreasonable, but avoiding prompt
> demonstration of the IFR technology would be a mistake. There is
> lots of room for healthy competition as reactor deployment proceeds.
>
> George S. Stanford, Ph.D.
> Reactor physicist, retired from Argonne National Laboratory
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> At 04:48 PM 11/16/2009, Jaro Franta wrote:
> FYI, here's a new article in Chemical & Engineering News:
>
> http://pubs.acs.org/cen/email/html/8746sci2.html
> Reintroducing Thorium
> November 16, 2009 Volume 87, Number 46 pp. 44-46
> A largely forgotten natural resource holds vast nuclear power potential
>
> Jaro
> ^^^^^^^^^^^^^^^^^^^^^^^^^
>
> -----Original Message-----
> From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
> Behalf
> Of Otto G. Raabe
> Sent: November-12-09 6:04 PM
> To: radsafe at radlab.nl>
> Subject: [ RadSafe ] Thorium nuclear fuel cycle
>
> November 12, 2009
>
> Can anyone provide some information about the thorium nuclear fuel
> cycle and the reason it is supposed to be a better
> proliferation-resistant nuclear fuel cycle.
>
> Thanks,
>
> Otto
>
> **********************************************
> Prof. Otto G. Raabe, Ph.D., CHP
> Center for Health & the Environment
> University of California
> One Shields Avenue
> Davis, CA 95616
> E-Mail: ograabe at ucdavis.edu
> Phone: (530) 752-7754 FAX: (530) 758-6140
> ***********************************************
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