Proliferation Resistance and Nuclear Power

[jaro]

Experience With Syria Exemplifies Challenge That Detection Presents
By Joby Warrick, Washington Post Staff Writer
Monday, May 12, 2008; Page A16

Syria went to extraordinary lengths to conceal its undeclared construction of a plutonium-producing nuclear reactor from spies in the sky and on the ground in recent years, according to a draft report by independent nuclear experts briefed by Bush administration officials.

The effectiveness of the camouflage effort raises new doubts about the prospects for certain detection of future clandestine nuclear weapons-related activities, the Institute for Science and International Security concluded in its report on the Syrian facility. "This case serves as a sobering reminder of the difficulty of identifying secret nuclear activities," the report said.

U.S. intelligence officials last month released images of the Syrian facility before it was bombed by Israel last September and bulldozed by the Syrian government once the raid became public. U.S. and Israeli officials have said the facility was a nearly completed nuclear reactor built with North Korean help and fitted with a false roof and walls that altered its shape when viewed from above.

According to the ISIS report to be released this week, the fake roof was just the start. Syrian engineers went to "astonishing lengths" to hide cooling and ventilation systems, power lines and other features that normally are telltale signs of a nuclear reactor, authors David Albright and Paul Brannan wrote.

For example, the main building appears small and shallow from the air, but it was evidently built over large underground chambers -- tens of meters in depth -- that were large enough to house the nuclear reactor, as well as a reserve water-storage tank and pools for spent fuel rods, the report said.

An extensive network of electrical lines appears to have been buried in trenches. Traditional water-cooling towers were replaced with an elaborate underground system that discharged into the Euphrates River. And, instead of using smokestack-like ventilation towers prominent at many reactor sites, the ventilation system appears to have been built along the walls of the building, with louver openings not visible from the air, the authors contended.

The ISIS report noted that early skepticism that Syria was building a reactor there was based partly on the observable absence of revealing features. "The current domestic and international capabilities to detect nuclear facilities and activities are not adequate to prevent more surprises in the future," the report warned.

Albright, a former U.N. weapons inspector, said his conclusions were based not only on photographs of the Syrian site but also on interviews with government officials who closely monitored the facility while it was under construction.

Syria has repeatedly denied that the Al Kibar facility was a reactor. Its ambassador, Imad Moustapha, at a April 25 news conference in Washington described the allegations as "absurd, preposterous stories." "This administration has a proven record of falsifying and fabricating stories about weapons of mass destruction," he said.

On Wednesday, International Atomic Energy Agency director general Mohammed Elbaradei said his organization should be able to report in coming weeks whether the facility was an undeclared nuclear reactor.

[Kirk Sorensen]

They aren't dumb--they learned from the lesson of Osirak in Iraq.

It's like I've been saying for a long time--if countries want weapons, it will be very difficult to stop them, and they won't use power reactors.

[dwalters]

I saw an interesting article tonight off of nucnews.com. It was a conservative analysis of the reason every Arab gov't in the Gulf, including obvious client states like Kuwait and Iraq, have gone out of their way to defend the right of Iran to it's nuclear program *as is*. All these gov't want the US to shut up. Basically. What gives?

The analysis suggests that all this dovetails with the Gulf stages own interest in developing nuclear energy...there is a mini-renaissance going on there if you are not following the news with Egypt (not a gulf state, per se) leading the way with a proposal for like 8 nuclear plants. Even impoverished "we-ain't-got-no-stinkin-oil" Yemen wants a plant. The French and Russians are in the lead to provide skills, product, and overall oversight. The analysis believes that these states can, *if need be*, convert their civilian programs over to military ones to confront Iran if Iran tries to bully it's way around the Gulf. That Iran has *never* tried to do this before doesn't seem that relevant (including the Iran/Iraq war...where Iraq attacked Iran).

I agree with Kirk: any state that WANTS nuclear weapons will get them. In the case of the Middle-East, with it's abundance of engineering students, indigenous uranium sources and...capital, there is zero any one can do about it other than persuasion and giving *positive* incentives NOT to do it. Peace over there would be a big incentive, IMO.

Just thinking out loud...

David

[honzik]

Brian Wang posted a nice link on his blog to a study looking at the proliferation resistance of Gen III+ and Gen IV reactors.

Here's his post:

http://nextbigfuture.com/2008/12/prolif ... tible.html

and here's the link to the study:

http://www.cissm.umd.edu/papers/files/f ... _power.pdf


There is an extensive section on Molten Salt Reactors starting at page 46 in the paper.

[jaro]

Brian Wang posted a nice link on his blog to a study looking at the proliferation resistance of Gen III+ and Gen IV reactors.

Here's his post:

http://nextbigfuture.com/2008/12/prolif ... tible.html

and here's the link to the study:

http://www.cissm.umd.edu/papers/files/f ... _power.pdf


There is an extensive section on Molten Salt Reactors starting at page 46 in the paper.

Thanks Honziku,

Seems to me that the blog takes a considerably more up-beat position than the referenced study.
In fact, the study cites certain conclusions that would, I suspect, be very unpopular on this forum (I can understand why you avoided quoting any of it) :

without the addition of uranium, i.e., in a pure thorium cycle, only a chemical separation would be required to obtain weapon-grade U-233, which is excellent weapons material.

From a weapons physics perspective, U-233 is superior to U-235, and in some respects, is also superior to Pu-239.

.....the rate of spontaneous fission in weapon-grade U-233 due to the residual U-238 is small enough to permit its use in gun-type fission weapons

.....The only significant disadvantage of U-233 is that its production is generally accompanied by the production of U-232 via (n, 2n) reactions with Th-232, U-233, and U-235.

.....the dose 1 meter from a sphere one year after separation is about 1 rem/hr and 10 rem/hr per kilogram uranium for the molten salt reactor and the RTR, respectively.
......The U-233 would be accompanied by radiation from U-232, an industrial disadvantage, but a minor nonproliferation advantage.

Aside from that, there is an interesting observation:

While a substantial effort would be required to revive the molten salt reactor concept, which has languished since the operation of two experimental reactors in the 1950s and 1960s, such an effort should be seriously considered, but not for the goal of validating the DMSR per se.

Rather, through modification of the chemical processing system in a DMSR to remove more fission products, it may be possible to combine the proliferation resistance features of the DMSR with the potential for breakeven breeding of a molten salt reactor operated on the pure thorium cycle. After startup, such a sustainable denatured molten salt reactor (SDMSR) wouldn’t require any more enriched uranium, and the total amount of mined uranium would be reduced by a substantial factor, ~ 90%. Such a reactor would provide a more proliferation-resistant, and potentially also a safer and more economic alternative to the standard plutonium fast breeder in a situation where there isn’t a need for a rapid growth in installed nuclear capacity unconstrained by a lack of uranium.

To me, the middle part of this quote is all about agressive fuel processing, as I envision for the HW-MSR.

The second part seems to point to places like India, where there is a need for a rapid growth in installed nuclear capacity which is in fact constrained by a lack of uranium.....

IMO, the authors of this study are "on the ball" in every respect.

[David]

I think someone else posted that paper on another thread but can`t recall where. I remember being pretty surprised that the authors seemed to know what they were talking about it terms of molten salt reactors.

I do agree with you Jaro that on average we do tend to take too rosy a picture in regards to proliferation dangers of the pure Th-U233 cycle but I would certainly not think it makes the concept a no go especially given the safeguards we can put in place (I particular like Kirk`s suggestion of having molten U238F4 standing by that can dilute the core salt in a moments notice.

That said, everyone should also be quite aware that just as that report recommends we can also run almost any design we can think of in a denatured state by adding U238 to the system. There are plenty of drawbacks to this and in most (not all) designs it will make break even harder to obtain. People may also complain that all the extra plutonium in the system makes things "dirtier" but as long as we do employ a method to remove and recycle Plutonium and the higher actinides, the waste stream can be almost as good for long term radiotoxicity as a pure Th-U233 cycle.

The system they talk about, the DMSR (ORNL TM 6413) was put forth around 1979 and they thought they`d be able to just barely break even on breeding while keeping the system denatured (under a weighted average of 20% U235 and 12% U233). I have studied that system numerous times and I should comment that they never really proved definitively that they could break even but at least with this concept, a little additional fissile by way of LEU can make up the shortfall.

Many people highly favor fast spectrum designs to achieve denatured operation, especially as U238 can give a substantial fast fission bonus but I don`t think it will be as easy as many think. The fact that the French group with all their work on fast spectrum designs have never promoted a denatured cycle speaks to that.

Anyhow, again to sum up many people prefer the simplicity of the pure Th-U233 cycle and think proliferation worries are overblown but if proliferation problems (real and/or imagined) prove a show stopper almost any design can also run denatured.

David L.

[jagdish]

Fire, the original energy, causes a large amount of destruction every day. We try to regulate it and have businesses and organizations to deal with its effects but wisely no attempt has been made to restrict its use, except perhaps by children. Nuclear fission is the new, more intense fire and some people try to keep it out of others hands.
That epicenter of Islamic Fundamentalism, Pakistan already has nuclear weapons and is also a mart of export. It is also unable to control Extreme Islamic terrorism within its own territory or its export. A prominent national leader (no dove herself, only democratic) was assassinated by the the extremist elements some time back. Preventing others states from right of a deterrent would be laughable if it were not so sad.
So, it is time to concentrate on technology for long term benefits. 238U and thorium are the bulk nuclear fuels. Fissile isotopes are only the kindling's for them and cannot be wished away. At least LFTR concept realises that. The fast 238U-239Pu cycle is the key to the kindling material, besides being a device to use238U in the Spent Nuclear Fuel (SNF) and depleted uranium. With excess of particulate matter from coal with adverse effects on health and sulfur from both coal and oil bad even for machinery, it is time for the new fire.
In the US, even the SNF storage scheme is up against resistance. It is time to give some consideration to people whose land and environment are effected by uranium mining and minimize it by going for closed cycle and using entire uranium and some thorium too.

[Lars]

The french group looked at denatured while they were still moderated. I don't think they have relooked at denatured since they started working on fast spectrum reactors. So, I don't think there are any conclusions that can be drawn regarding fast spectrum and deantured from their experience.

Second, from a waste perspective I see no difference between 233U and plutonium.

[David]

The french group looked at denatured while they were still moderated. I don't think they have relooked at denatured since they started working on fast spectrum reactors. So, I don't think there are any conclusions that can be drawn regarding fast spectrum and deantured from their experience.

Second, from a waste perspective I see no difference between 233U and plutonium.

Lars,

I certainly may have missed some of their work but I think what you might be thinking of was some studies on starting up a graphite design on 30% enriched uranium (above the 20% limit) and slowly converting back to the pure Th-U233 cycle. When I asked one of the researchers about running completely denatured, she said she thought it maybe a good idea to examine but I don't think they've really looked at it. With the huge body of work they've done over the last years it is a shame they didn't examine this avenue more closely. Even simply trying to reproduce the work of ORNL on the DMSR (Denatured Molten Salt Reactor) would have been a huge help.

David L.

[Kirk Sorensen]

Reading over this really made me wonder about the "advantage" of a denatured MSR. To have a denatured MSR, you must continuously be adding U238 to keep the bred U233 denatured, right?

So what's to stop some country from simply stopping the denaturing? It's not that hard to stop. Just throw the switch on the panel and turn off the feature.

Maybe we "trust" them not to stop denaturing. Well, if we trust them, then why don't we run the pure cycle? Do we think the temptation to proliferate will be too great?

If you denature the uranium, you'll make plutonium. It's that simple. In one part of the document they say that reactor-grade plutonium is a weapons-threat. So denaturing uranium doesn't buy you much.

They really gloss over the issues that U232-gammas will have for practical bombs. They make it sound like if you remotely fabricate the pit, that you're all set. But they don't talk about the explosives or the electronics or all the other things that will get barbecued by gammas. They simply focus on the pure explosive potential of U233 at the exclusion of the "ilities". All that other stuff is why we don't have U233 weapons today, thank goodness.

I still think the two-fluid, pure cycle reactor with "just-in-time" denaturing is a better bet than the plutonium-generating DMSR. With JIT denaturing, you can wire the whole system to denature core and Pa decay tank if some high-level command isn't executed.

[honzik]

I've been thinking lately about the synergy that might be possible between an LFTR and an IFR. How hard would it to put a thorium blanket around an IFR with the express purpose of breeding U234 along with the U233? The U234 could then be transferred to the LFTR. I'm presuming that an IFR would have a relative excess of neutrons, and therefore can still be designed to breed with a few neutrons lost to the thorium blanket. Anyway, with the U234 back in the LFTR, the neutron economy wouldn't suffer too much because the U234 would breed to U235, which would give back maybe a bit less than two neutrons. With the U234 in the mix, you'd have denaturing, given the difficulty to separate U234 and U233. And, you'd minimize the amount of Pu that was bred, because there'd be no U238 in the LFTR at all. Perhaps the synergy could go both ways: the Np237 that's separated out from the LFTR could then be plugged in to the IFR, which would burn quite well in a fast reactor.

Just a thought. Any comments?

[Kirk Sorensen]

I don't think U234 is much of a denaturant, and anyways, I don't think we could produce enough U234 to make a difference. The capture-to-fission cross section of U233 is nearly the same in the fast spectrum as in the thermal spectrum, so in each case you'll be fissioning 10 U233 nuclei for every 1 U234 you produce.

[Lars]

It isn't the rate that is critical, rather it is the inventory. The inventory for a 1GWe pure Th/U, fast spectrum two fluid reactor is:
233U 4970kg
234U 1750kg
235U 555kg
236U 549kg
237U <1kg (decays to 237Np pretty fast)
238U 1kg (some capture on 237U before it can decay)

Still not enough to make it denatured but more than 10% 234U.
The dump tank idea is still the strongest anti-proliferation idea I've heard.
I hope to talk with some proliferation experts at Stanford.

[robert.hargraves]

I don't understand how the dump tank contributes to proliferation resistance. Dump U-238 into the fuel salt? Dump the fuel salt into a bed containing U-238?

Here's the text of an email I sent to the authors of the CISSM paper mentioned at the beginning of the thread. I hoping to get advocates of LFTR among the nonproliferation specialists. I had a long train ride back from DC, so I wrote this. I hope I didn't make too many errors.
--------------------------------
Harold Feiveson
Alexander Glaser
Marvin Miller
Lawrence Scheinman

Center for International and Security Studies at Maryland

Re: Can Future Nuclear Power Be Made Proliferation Resistant?

I am interested in the world's energy, climate, and pollution future. Consequentially I have had to learn more about nuclear proliferation than I anticipated. I read your helpful paper at http://www.cissm.umd.edu/papers/display.php?id=353. I have some comments that may be useful to you if you publish a follow-on document.

Liquid Fluoride Thorium Reactor (LFTR)
I have become convinced that the liquid fluoride thorium reactor (a molten salt reactor) holds promise for inexpensive, nonpolluting, low waste nuclear power. My comments are mainly from the point of view of the potential of the LFTR.

Atmospheric CO2 pollution
The LFTR holds the potential for producing electric power cheaper than from coal. Such power can undercut the economics of coal-fired power production, not just in the OECD countries, but in the developing nations such as India and China. Carbon taxes and/or cap-and-trade credits will not stop CO2 emissions. The United States did not sign Kyoto. Europe has spent $50 billion in such carbon credits, many of which flowed to the coffers of the worst polluters. CO2 emissions have risen in Europe. China and India will certainly never agree to such taxes that would withstrain their economic growth towards achieving an OECD lifestyle.

Power cheaper than from coal can overcome this problem, while creating a rising economic tide for all nations.

Aim High
An introduction to the benefits and technologies of LFTR can be viewed starting at http://rethinkingnuclearpower.googlepages.com/aimhigh.


Inexhaustibility
Thorium has an availability advantage of 3:1 over uranium, and 100% would be used up in the LFTR, vs 0.7% in a standard LWR with a once-through fuel cycle. I do admit that uranium power would not be much more expensive than now even if ore depletion makes us resort to adsorbing uranium from seawater.

LFTR fuel supply
In your Table 4.1 for a 1 GWe reactor the Thorium MSR initial core requirement of 17.5MT 20 % LEU seems excessive. Compared this to about 5MT in the Energy From Thorium at posts in http://energyfromthorium.com/forum. Also, the LFTR can be started with spent LWR fuel instead of LEU or HEU.

In the table, Ongoing U(nat) requirements should be zero, not 50 MT/yr. The reactor would require about 1 T/yr of thorium. No enrichment SWUs would be required.

Total discharge of spent fuel will be the fission products, only, or about 1 T/yr, not 5-9 T. Total discharge of fissile material is not 25 kg/yr as stated in the table, but perhaps 30 g/yr. This amount is a subject of debate and research on the forum, where some engineers say "trace" or "virtually zero" or "none". TRUs are all consumed in the LFTR, except some TRUs leak into the fission product waste stream, depending on the chemical process to separate the FPs from the fuel salt. Eventually the tradeoff will be chemical processing cost vs tolerable fissile waste.

The similar table on page 36 is sized for a reactor half that size. You labeled it 500 GWe, but I think you mean 500 MWe.

A strong advantage of the LFTR will be the lack of need (or excuse) for states to build centrifuge enrichment plants.

Pebble bed reactor
I have been an advocate of the pebble bed reactor, too. It has many of the same advantages of modular construction, intrinsic safety, high temperature and conversion efficiency, and on-line refueling -- as does the LFTR. One advantage of the PBR is that the waste fuel is encapsulated in layers of pyrolytic carbon and silicon carbide that virtually prevent reprocessing. It is also an advantage in that the fuel form is ready for direct geological storage. Many people are fearful of geological storage of such waste.

Perhaps the PBR could be a power generator of choice in the non-weapons states. I do not agree with your idea of a technology democracy where all state have equal rights to all nuclear technologies. I would hope the NPT to continue for another 50 years, or more. Most of the world population is in the weapons states (also the CO2 producing states) and could be first served by LFTRs, until a level of comfort with nonproliferation features of the LFTR is achieved and they could be exported worldwide.

Guaranteed fuel supply
If uranium-powered reactors become the power source of choice, some international, strong, guarantees of nuclear fuel supply will be essential to prevent non-weapons states from resorting to building uranium enrichment factories. This is one of the goals of GNEP, to which about a dozen nations have subscribed. Your paper says the GNEP is "shaky".

If, instead, LFTR power plants are widespread, there is no need for such a guaranteed fuel supply. Thorium is widely available, with many alternative sources of supply and no need to control it.

Other proliferation paths
Nowhere in this paper do you mention the CANDU or heavy-water technology, which allows countries like India to manufacture weapons-quality plutonium without access to enrichment. I believe the Russia RBMK reactors, like Chernobyl, also can do this, once started up.

Latent proliferation
One way to prevent the spread of "latent proliferation" is not to incentivize development of nuclear engineering skills in every nation. If the US, or other technically advanced states, could export LFTR (or PBR) modules at competitive costs, with internationally guaranteed fuel supplies, there would be no need for universal, independent, national cadres of nuclear experts.

I think terrorism by theft of HEU from research reactors is being addressed, worldwide by converting them to operate on LEU.

LFTR nonproliferation measures
The LFTR does convert Th-232 to U-233. A 1GWe LFTR might have 1 T of U-233 dissolved in the molten salt. An LFTR captured by a technically advanced non-weapons state might, conceivably, be modified to extract the U-233 to make many nuclear weapons. Several nonproliferation techniques can be designed into the LFTR to prevent this.

(1) The designs and controls of the LFTR can ensure a breeding ratio of 1.0, not higher. With no surplus, any removal of U-233 would shut down the LFTR, revealing a theft.

(2) The fuel salt containing U-233 can be diluted with U-238, so that HEU U-233 can not be extracted by chemical processes, only expensive enrichment technologies such as diffusion, centrifuge, or laser isotope selection.

(3) The fuel salt will certainly contain amounts of U-232, whose decay chain includes isotopes that emit high-energy gamma radiation hazardous to weapons builders, should the uranium be extracted.

(4) The LFTR could be designed for automatic injection of U-238 to dilute (denature) the U-233 to weapons-useless levels on indications of tampering, or by remote control from an international body.

(5) U-233 itself is more radioactive and hazardous to work with than U-235.

(6) U-233 removed from a LFTR will be contaminated with fission products hazardous to weapons builders.

(7) The LFTRs can be designed to operate without personnel, lowering operating costs, risks of experimentation, errors in operator training or execution, and exclusion of weapons-fabrication-intent technicians, engineers, or scientists from the LFTR. This operatorless mode also reduces the chance for "latent proliferation".

(8) Combinations of the above techniques can be employed. No single nonproliferation protection need be iron clad. The combination needs only to be sufficiently protective that creating a weapon from a LFTR would be an order of magnitude more difficult that building one in the least challenging ways. These time-tested ways are (1) centrifuge uranium enrichment for HEU to make a gun-type uranium bomb, (2) CANDU/RBMK production of PU-239 to make an implosion-type plutonium bomb.

Terrorism
Regarding terrorist attacks on facilities the LFTR, like the PBR, is designed for passive air cooling in the event of permanent disruption of cooling.

Submarines
Regarding the prohibition of HEU in naval reactors, I don't think you can persuade governments to give up nuclear submarines! Besides, submarines are nuclear weapons.

International control
I don't see how we could put all uranium mining, milling, enrichment, fissile materials depots, etc under international control. Even embassies are sometime taken over in hostilities.

Nuclear batteries
With respect to the hub-spoke nuclear batteries idea, both NuScale and Hyperion have recently announced attractive products.

Reprocessing
Expansion of uranium nuclear power may lead to ore depletion and the need to change from a U-235 once-through cycle to reprocessing to make use of the 99.3% of U-238 available. Adopting the LFTR will avoid extensive build-out of plutonium-isolating reprocessing plants, if the thorium/uranium fuel cycle is adopted. In an LFTR no fissile material is ever isolated. None is transported out. None is transported in, except at startup.

Robert Hargraves
Hanover NH

[Kirk Sorensen]

I don't understand how the dump tank contributes to proliferation resistance. Dump U-238 into the fuel salt? Dump the fuel salt into a bed containing U-238?

No, the U238 isn't in the "dump" tank, meaning the emergency drain tank used for passive cooling. The U238 can be injected, as desired, into the core or protactinium decay tank.