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PostPosted: Nov 24, 2009 9:20 am 
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Ont. nukes may provide answer to shortage of key compound in U.S. bomb-detectors
Canadian Press, 23 November 2009
BY MARIA BABBAGE

TORONTO _ Ontario may provide the answer to a U.S. shortage of a key compound needed for new technology that can detect smuggled nuclear bombs.

The American government has reportedly stopped deploying the new detectors at ports around the world because it's run out of helium 3.

Ontario's CANDU reactors make the substance that helium 3 comes from, but it's not currently separated.

Ontario Power Generation, a utility owned by the provincial government, has talked to U.S. officials about whether it could supply them with helium 3, Energy and Infrastructure Minister Gerry Phillips said Monday.

"But I understand it's just at the discussion stage, no decisions have been made on it,'' he said. "That's as much as I know about it.''

OPG is trying to figure out whether it can extract helium 3 and what it might cost, said spokesman Ted Gruetzner.

"Those are all the things that we don't know,'' he said.

"Right now, it's really at the very preliminary stage and that would be part of the process that we will go through to decide whether we want to do it _ how much it would cost versus how much it would presumably sell for.''

Helium 3 comes from tritium _ an ingredient in hydrogen bombs _ which OPG extracts from heavy water used in its nuclear reactors.

The water picks up tritium during the CANDU process, which is extracted at OPG's tritium-removal facility in Darlington, he said. Much of the tritium is stored safely on site while the water goes back into the reactor.

Ontario has four CANDU reactors currently operating at Darlington station near Clarington, six at its Pickering station east of Toronto and six others in Kincardine, Ont., leased to Bruce Power LP _ all of which produce the so-called "tritiated'' water, he said.

But only OPG is capable of processing the water, because Bruce Power doesn't have a tritium-removal facility, Gruetzner said.

New Brunswick and Quebec also have CANDU reactors, but Gruetzner said he's not sure if they extract tritium from their heavy water.

Last week, an official from the Department of Homeland Security testified before a U.S. House subcommittee that the demand for helium 3 exceeds the supply by a ratio of 10 to one.

Representative Brad Miller, the committee's chairman, wrote to Homeland Security Secretary Janet Napolitano last week, saying the department received "plenty of signs in the past year that the lack of helium 3 could be a show-stopper'' for the new detection machines.

Miller also urged Napolitano to abandon the program, which he said could cost US$2 billion.

"This may be an opportunity for the department to use the helium 3 crisis as an off-ramp for this troubled program,'' he wrote in the Nov. 20 letter.

The New York Times reported Sunday that the Department of Homeland Security spent $230 million to develop the new detectors, but had to stop deploying them due to the shortage.

The machines are supposed to detect plutonium or uranium in shipping containers. The U.S. government wanted 1,300 to 1,400 machines, which cost US$800,000 each, for use in ports around the world to thwart terrorists, the Times reported.


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PostPosted: Nov 24, 2009 12:07 pm 
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jaro wrote:
Ont. nukes may provide answer to shortage of key compound in U.S. bomb-detectors
Canadian Press, 23 November 2009
BY MARIA BABBAGE

TORONTO _ Ontario may provide the answer to a U.S. shortage of a key compound needed for new technology that can detect smuggled nuclear bombs.

The American government has reportedly stopped deploying the new detectors at ports around the world because it's run out of helium 3.

Ontario's CANDU reactors make the substance that helium 3 comes from, but it's not currently separated.

Ontario Power Generation, a utility owned by the provincial government, has talked to U.S. officials about whether it could supply them with helium 3, Energy and Infrastructure Minister Gerry Phillips said Monday.

"But I understand it's just at the discussion stage, no decisions have been made on it,'' he said. "That's as much as I know about it.''

OPG is trying to figure out whether it can extract helium 3 and what it might cost, said spokesman Ted Gruetzner.

"Those are all the things that we don't know,'' he said.

"Right now, it's really at the very preliminary stage and that would be part of the process that we will go through to decide whether we want to do it _ how much it would cost versus how much it would presumably sell for.''

Helium 3 comes from tritium _ an ingredient in hydrogen bombs _ which OPG extracts from heavy water used in its nuclear reactors.

The water picks up tritium during the CANDU process, which is extracted at OPG's tritium-removal facility in Darlington, he said. Much of the tritium is stored safely on site while the water goes back into the reactor.

Ontario has four CANDU reactors currently operating at Darlington station near Clarington, six at its Pickering station east of Toronto and six others in Kincardine, Ont., leased to Bruce Power LP _ all of which produce the so-called "tritiated'' water, he said.

But only OPG is capable of processing the water, because Bruce Power doesn't have a tritium-removal facility, Gruetzner said.

New Brunswick and Quebec also have CANDU reactors, but Gruetzner said he's not sure if they extract tritium from their heavy water.

Last week, an official from the Department of Homeland Security testified before a U.S. House subcommittee that the demand for helium 3 exceeds the supply by a ratio of 10 to one.

Representative Brad Miller, the committee's chairman, wrote to Homeland Security Secretary Janet Napolitano last week, saying the department received "plenty of signs in the past year that the lack of helium 3 could be a show-stopper'' for the new detection machines.

Miller also urged Napolitano to abandon the program, which he said could cost US$2 billion.

"This may be an opportunity for the department to use the helium 3 crisis as an off-ramp for this troubled program,'' he wrote in the Nov. 20 letter.

The New York Times reported Sunday that the Department of Homeland Security spent $230 million to develop the new detectors, but had to stop deploying them due to the shortage.

The machines are supposed to detect plutonium or uranium in shipping containers. The U.S. government wanted 1,300 to 1,400 machines, which cost US$800,000 each, for use in ports around the world to thwart terrorists, the Times reported.


It sounds like a case for using natural lithium rather than isotopically separated lithium in MSRs.

:P

I saw that article on the consequences of nuclear ignorance. Frankly, I'm not all that concerned though about so called "nuclear terrorism."


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PostPosted: Nov 24, 2009 12:23 pm 
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NNadir wrote:
It sounds like a case for using natural lithium rather than isotopically separated lithium in MSRs.


If you use natural lithium you'll never even be able to turn the thing on in the first place. Your k-effective will go from about 1.0 to about 0.005 or something. I know because one time I forgot to specify the lithium isotopic concentrations in one of my neutronics decks and the k-effective was abysmal.


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PostPosted: Nov 24, 2009 7:22 pm 
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Kirk Sorensen wrote:
NNadir wrote:
It sounds like a case for using natural lithium rather than isotopically separated lithium in MSRs.


If you use natural lithium you'll never even be able to turn the thing on in the first place. Your k-effective will go from about 1.0 to about 0.005 or something. I know because one time I forgot to specify the lithium isotopic concentrations in one of my neutronics decks and the k-effective was abysmal.


Well, I have to be perfectly honest in saying that I don't happen to know much about the cross sections of lithium isotopes off the top of my head, because basically I'm not that interested in them. I'm not a FLIBE kind of guy.

But I just called up the Table of Nuclides and looked at the graphs, and I see that you're right.

Nevertheless, having a large cross section could be good or could be bad depending on geometry or purpose.

I am not fond in general of any system that starts with a requirement for isotope separation, since inherently there is an energy, thermodynamic and (as follows) an environmental penalty for isotope separation, except where such separation occurs chemically owing to decay.

The main exception to this claim of mine would be the case of deuterium and protium, where said separation is a byproduct of electrolysis (and other processes) and therefore trivial.


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PostPosted: Nov 24, 2009 8:12 pm 
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Lithium is low enough on the Z value that the mass difference may be large enough to seperate without using enrichment cascades and the like as needed for uranium. There just never was a large enough demand to develop lithium specific isotope separation.


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PostPosted: Nov 24, 2009 8:50 pm 
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NNadir wrote:
Well, I have to be perfectly honest in saying that I don't happen to know much about the cross sections of lithium isotopes off the top of my head, because basically I'm not that interested in them. I'm not a FLIBE kind of guy.


I know. But I am.


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PostPosted: Nov 24, 2009 8:58 pm 
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dezakin wrote:
Lithium is low enough on the Z value that the mass difference may be large enough to seperate without using enrichment cascades and the like as needed for uranium. There just never was a large enough demand to develop lithium specific isotope separation.


You know, I'm not quite sure how they separate lithium isotopes. I would imagine that some kind of membrane diffusion system would work quite well, but I actually don't know how it's done as a practical matter.

In theory, I suppose one could do it by some kind of fractional distillation process, as was used when Urey first separated deuterium, but I don't know that this is the case. Since lithium has a fairly high boiling point this would necessarily involve reduced pressure.

You are right though. It is much, much, much easier to separate light element isotopes than heavy isotopes. At Farm Hall, where the German nuclear scientists were held after World War II, and every word they spoke was secretly recorded, that was the first word out of one of their mouths, it may have been that over-rated guy Hahn who said it, "Those fellows have actually managed to separate isotopes!"

Everyone was startled to learn that someone had separated the heaviest known element's isotopes. It was only a few years after Urey first purified deuterium.


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PostPosted: Nov 24, 2009 9:17 pm 
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Current large-scale deuterium separation technology depends on the same principle that makes heavy water poisonous to drink: the relatively lethargic chemical reaction rates involving deuterated chemicals - as opposed to ordinary hydrogen-bearing chemicals.
Specifically, the chemical used in the process is hydrogen sulphide.

Other processes have better efficiency when the deuterium concentration is higher than natural ( 1 in ~7000), as in re-enriching contaminated D2O.

Natural Li isotopic abundance is more like the latter case -- much lower volumes need to be processed to get the desired isotope, compared to D in water.

In low-volume isotope separation, higher energy processes such as MVLIS are favoured over chemical ones.


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PostPosted: Mar 05, 2010 2:56 pm 
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Tritium is reasonably easy to produce in a nuclear reactor, even a PWR. Some of the control rods are replaced with rods containing lithium. If you wanted to do it in a MSR, you'd probably be best off using lithium in seperate, enclosed irradiation targets and not in the salt mix. There's obviously a limit to how much can be produced because of the fact that there are only so many excess neutrons to absorb and if you overdo it, you'll shut down the reactor.

It's currently being done at a couple reactors run by the TVA. It could be done at more power reactors. It's done in the US to replenish the supplies for boosted nuclear weapons use. In Sweden and elsewhere it's done for general purpose use, such as illumination of compasses, wrist watches, exit signs, gun sights and certain microwave generating tubes. Of course, in the US it's always going to get the whole "proliferation concerns" thing going. Of course, much more can be made if you use a non-power reactor which is designed with an extra high surplus of neutrons for irradiating targets.

CANDU reactors don't produce a whole lot of tritium. It's a byproduct from the absorption of neutrons by deuterium, but the cross-section is pretty low. If it's tritium production that you want, the lithium-6 method is the way to go.

As for Helium-3, obviously that's going to take some time to get from the tritium. Most He-3 comes from reprocessing the tritium from old warheads in the US and Russia. There's a fair amount in warheads, since most have not had their tritium replaced in at least a few years and we've been at this since the 1950's. Another source could be better recollection and recycling of things like exit signs.

As it stands, most tritium exit signs that are disused or are past their lifetime and no longer glow brightly end up in landfills. They're not supposed to be disposed of like that. They're supposed to be returned to the manufacturer, and some are. However, the disposal is not enforced very well. They could be a valuable source of He-3, because after 20 years, more than two thirds of the tritium has become he-3, up to several milliliters.

I'd suggest that the way to deal with this would be to have a deposit on them, kind of like the way that soda cans have a five cent deposit. It should obviously be more. Put a big engraving on the back that says something like "DO NOT DISPOSE IN LAND FILL. CALL 1-800-XXX-XXXX for FREE RETURN SHIPPING BOX. A $50 CHECK FOR EACH SIGN RETURNED" That seems like it would stop most demolition workers or property owners from tossing them.


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PostPosted: Mar 05, 2010 6:34 pm 
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Might also make for a relatively short wall - life for them in places like movie theaters.


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