Tri-Alpha Rumor

[MirariNefas]

A rogue nation or organization would have little concern for the technicions killed off in processing and assembling the bomb.

Well I'm concerned about it. Rogue organizations (terrorists living in caves) can't have that many people competent in the nuclear sciences, so when they die it inhibits a repeat performance.

[Axil]

I'm sceptical of the nonproliferation potential of thorium breeders. The Uranium 233 produced is not ideal for bombs, but I understand it might actually be easier to build. The Uranium 233 halflife limits the shelf life of the bomb- use it or lose it. And it fissions too easily. I understand only a few percent of the isotope would fission before the bomb blew itself apart- a fizzle, but that only means that a bomb hidden in a truck might only blow up a small city instead of a large city. It would also serve as a good trigger for a dirty bomb. A rogue nation or organization would have little concern for the technicions killed off in processing and assembling the bomb. The only saving grace may be that it would be more difficult to hide from radiation moniters.

.

IMHO, U233 made from thorium 232 in a fusion/fission hybrid is impossible to make into a bomb of any type because you can’t get anywhere near it without dying. The fission people call this self protection.


The International Atomic Energy Agency (IAEA) says a reactor and/or its fuel is self protected when any human that gets to within a meter of the reactor and/or its fuel will die in 5 minutes or less.

If a reactor and/or its fuel is not self protected then it can be subject to proliferation, it must be guarded against any credible threat.

U233 can not be made without producing U232. It is U232 and its daughter by products that are dangerous. Freshly produced U232 with a concentration of 1% U232 is self protected. U233 made with a fast spectrum neutron source over 6MeV contains lots of U232. If U233 is made with a neutron source at or above 10 MeV, U233 contains a huge about of U232.

And the gamma level from U232 only goes up with time. Over a extended period of time, the gamma levels from U232 goes up to a maximum of 100 times.

After 10 years of U233’s creation, it would take 1800 tons of lead shielding to make a critical assembly (5 Kgs) of U232/U233 safe to get near. So once in a reactor, U233 must stay in the reactor until it is consumed or it must be handled by purpose build remotely controlled equipment in a hot cell.

Such “hot” U233 can be detected for miles away so a U233 bomb plant must be deployed deep underground and be totally automated. And then you could not get within a mile of a U232/U233 bomb (no lead shielding) without dying.


On the other hand, the dangerous feature of plutonium is that it is not very radioactive and its level of radioactivity only goes down with time. A bomb can be fashioned out of old PU239 using a glove box.

This is why waste from a U235 fission source is dangerous. Over time, the radiation level of U235 waste drops with time and it is not radioactive enough to be self protecting.

[D Tibbets]

Thanks, Axil, for the details.
So, making a U233 bomb would be very difficult. I was thinking that a plant would nessisarily have the equipment needed for remote handling of the spent fuel rods. I thought since the U233 could be chemically seperated from the thorium much easier than isotopic seperation, this would be more meniable to primitive remote techniques.

Does the U233 need to be purified above its initial levels in the spent fuel rod (or perhaps I should say in the charged fuel rod where a substabtial portion of the thorium has been converted into uranium 232 and 233)?

If a reactor is built in a country that swears to follow the rules, but then persues bomb development, identifing this is already possible(or at least predictable), even with low penitrating radiation products like plutonium. What is lacking is the political will to do anything about it.

Even if a fission bomb cannot be made without great sacrifice, a dirty bomb (especially with U232) would be devistating. The question would boil down to how much more dangerous this would be compared to conventional spent fission fuel rods, and how would these (of either type) be controlled. So far the track record is not great, at least for the Russion, and French? reactors built in client countries.

Dan Tibbets

[Axil]

So, making a U233 bomb would be very difficult

I would state it more strongly, it is near impossible to make a bomb out of U233 produced by fusion. Any terrorist or rouge nation would use PU239 instead; absolutely.

I will now mention that U233 would be denatured. It would be contaminated with U234 and U236 which would stop a bomb reaction. Isotopic separation of U234 and U236 from U233 is very difficult without U232 contamination. With U232 contamination … forgets it.

Even if a fission bomb cannot be made without great sacrifice, a dirty bomb (especially with U232) would be devistating.

If terrorists are willing to die, then a dirty bomb is possible to build, but it would take the deaths of thousands of terrorist to do the job each working in one minute shifts before incapacitation. But the undetected transport and deployment of such a bomb would be near impossible. Radiation detectors miles away would light off.

Making a dirty bomb from light water reactor waste is so much easier on the terrorist membership roles.

[Axil]

I will address the thorium fuel cycle since it is highly proliferation resistant (I think proliferation proof) when coupled with fusion in preference to the uranium fuel cycle and its plutonium (a proliferation risk) byproduct.

In other words, each D-D fusion produces one neutron that breeds 4 U233 atoms.

In the Thorium fuel cycle you can deliberately spike the Thorium-232 with Thorium-230 to make extra U-232 and make it very hot. Hot enough to not be usable in a bomb.

Can it be used in a bomb? Yes, the US did it by pulling the Folgers switch on a bomb core in Operation Teapot MET test. There's a chart of the nastiness of U-232 radiation effects within 1 month of use.
Obviously they must have separated out the Thorium-230 from the Th-232 so that there wasn't a yield of U-232 in the U-233 bred.

See the thread here:
http://www.energyfromthorium.com/forum/ ... 8774#p8774

Quoted from Kirk Sorensen:
http://www.energyfromthorium.com/images ... aldose.gif

Quoted from argo:
Actually the 1955 "MET" test from Operation Teapot used a U-233/Pu core swapped out for the U-235/Pu core.
Quote from http://nuclearweaponarchive.org/Usa/Tests/Teapot.html

MET stands either for "Military Effects Test" or "Military Effects Tower" (according to Frank Shelton). This was a LASL test of a composite U-233/plutonium bomb core (the first test by the U.S. to use U-233) in a Mk 7 HE assembly. The 30 inch diameter spherical implosion system weighed 800 lb.

The primary purpose was to evaluate the destructive effects of nuclear explosions for military purposes. For this reason, the DOD specified that a device must be used that had a yield calibrated to within +/- 10%, and the Buster Easy device design was selected (this test gave 31 kt and used a plutonium/U-235 core). LASL weapon designers however decided to conduct a weapon design experiment with this shot, and unbeknownst to the test effect personnel substituted the untried U-233 core. The predicted yield was 33 kt. The actual 22 kt was 33% below this, seriously compromising the data collected.

http://nuclearweaponarchive.org/Usa/Tests/Tpotmet1s.jpg

------------------------------------------------------
The US was looking into many emergency weapons construction plans, but the ease and yield of Pu and U-235 is more bang for the buck.
This may explain why the US buried 3500 metric tonnes of Thorium Nitrate at the Nevada Test Site back then, just in case.

There is another post I found about reactor grade fuel simplified weapon test. It can be done without cooking the technicians, but it's of a lower yield. Somewhere in the range of .1 to 8 KT depending on how much material is used.

The US team actually used simple tools and techniques that terrorists would have access to. That's the scary part about the nuclear fuel cycle the nuclear players don't want you to know.

MSimon is right, the horse is already out of the barn, a long time ago.

It took the US government 20 years and untold millions to develop and perfect special very low energy thermal reactors at Hanford Washington to produce weapons usable U233 with only trace amounts of U232 present.

The key to weapons usable U233 production is ultra low energy breeding neutrons and they are not easy to produce.

In the U233 reactor development process, Hanford inadvertently contaminated their adjacent plutonium production lines many times; resulting in much unanticipated expense, prolonged plutonium production line downtimes and frequent shortfalls in plutonium production quotas. It was a great accomplishment when they finally produced U233 safe enough to use in a weapon. But as you noted, it was a disappointing fizzle and considered unreliable.

By the way, the Buster Easy device was a Plutonium/U233 device. No pure U233 bomb has ever been attempted.

The TH230 addition to the thorium feedstock is optional. A rogue state would not opt to implement this measure. As a result of its very hard neutron spectrum, a fusion thorium hybrid produces “hot” U233 as an unavoidable result of physical law; and it can not be avoided. This is why I like this reactor type so much.

The DOE produced about 1000 lbs of U233 between the mid 50’s to the mid 70’s. It is still around and very hard to get rid of. It is now old and growing hot.


The “reactor grade fuel simplified weapon test” involves plutonium from Light Water Reactor Wastes. These tests are no longer significant because of the increased fuel burn up levels achieved by new LWR designs.

The higher the fuel burnup levels are, the more PU238 it contains and the less weapons usable PU239 is for a gun type weapon.

[Skipjack]

Yeah, those anti nuclear lobbyists. First it was the threat of radioactive waste, then accidents, now it is proliferation.
Never short of an excuse why we are supposed to not build nuclear reactors (or now even fusion reactors that do not even exist) to fullfill our energy needs.
Meanwhile the rest of the world does not give a crap and is happily building one reactor after the other.
The truth ist that compared to the reactors in use in the worlds, there are comparably few nations with a nuclear weapons programme. Most of those that do have one, got their know how delivered (wilingly) from the US and/or Russia anyway. Strangely enough the two that cry "proliferation" the loudest of all (the only exception of willingly would probably be North Korea).
You cant really stop certain developments by trying to hold back progress. If the US does not develop a fusion reactor or a certain fission reactor type - be it proliferation safe or not- then someone else will. Maybe China, or South Korea, or Japan, or Russia, or even India. From there it will quickly spread into the rest of the world.
Then what will have been gained by stalling development in the US out of proliferation- concerns? Nothing!
All you would do with it, is loose is money and good engineers that would probably go elsewhere to do their thing.
No, preventing others from developing nuclear weapons is probably best done on the political stage. Of course that will never stop a small group of rogue crazies, be it a country or a terrorist organization. But those will always find a way anyway.

[Art Carlson]

Yeah, those anti nuclear lobbyists. First it was the threat of radioactive waste, then accidents, now it is proliferation.
Never short of an excuse why we are supposed to not build nuclear reactors (or now even fusion reactors that do not even exist) to fullfill our energy needs.

First? Then? Now?
These always have been and still are the primary (but not the only) problems of nuclear power. I respect the fact that many people on this forum have come to the conclusion that nuclear power is the best answer to our energy problem. It would be nice if you could also acknowledge that there is a down side to nuclear power that has led some knowledgeable and rational people to come to a different conclusion. Belittling your opponents and their reservations is not a good way to find the technically and politically optimum solution.

[Axil]

Re: optimum solution


Good engineers will always freely acknowledge and admit mistakes and flaws in their approach as a prerequisite to their mitigation. Engineers continually obsess over mistakes and flaws as problems to be overcome, they think about them constantly, even loss sleep over them.


On the other hand, good politicians will never freely acknowledge and admit to mistakes and flaws. Politicians tend to frame mistakes and flaws as advantages and discriminators of their approach or at least hope that they will be soon forgotten.


All the reactor designers that I know are good engineers who freely discuss the tradeoffs involved in their research. They universally acknowledge that anti-proliferation is a top priority in their designs.


You can always tell a politician from an engineer in the way he discusses and issue. An engineer will confine his criticism to the merits and tradeoffs of any given technical and scientific point of a design under discussion.


A politician will attempt to personally destroy his opponent, question his character, belittle his intelligence, cast doubt on his motives, impune his integrity, and cast aspersion on the legitimacy of his birth.


The main tool of the propagandist, the handmaiden of the politician is FUD; fear, uncertainty and doubt.


The main tool of the engineer is the essential truth and applicability of the facts at hand. The ultimate test that the engineer must face is absolute; that his design eventually works and this test breaches no excuse.


The main test of the politician is transitory; that his opinions and policies are accepted by the majority at least temporarily for some short term of time. The damage that is created by these opinions and policies will be the problem of the next guy to whom the buck will be eventually passed.


To get to the optimum solution in any situation, it is imperative to drill down on the facts and their long term implications and permanency and leave emotion and FUD outside in the cold.

[alexjrgreen]

On the other hand, good politicians will never freely acknowledge and admit to mistakes and flaws. Politicians tend to frame mistakes and flaws as advantages and discriminators of their approach or at least hope that they will be soon forgotten.

...

A politician will attempt to personally destroy his opponent, question his character, belittle his intelligence, cast doubt on his motives, impune his integrity, and cast aspersion on the legitimacy of his birth.

As a former politician, I don't recognise your job description.

A politician's job is to distribute inadequate resources in the fairest possible way. That may involve persuading people that their wants exceed their needs, and that other people's needs exceed theirs.

Trashing your opponents makes agreeing a settlement harder.

[D Tibbets]

It, is not that I oppose fission power. It is that I am dismayed by the cavalier attitued of orgaanzations/ nations that provide nuclear plants to costomers whith no or little real control over innapropiate operation of the plant. Certainly, any nation capable of building their own plants could use them however they desired (assuming international penilties did not make it too uncomfortablte for them). But at least this would buffer somewhat the rogue use by otherwise limited nations or organizations, especially those who felt they had little to lose by employing weopenized nuclear material.

The difficulty of anticipating and planning for accidents is another issue. At Chernobyl this was obvously done poorly. At three Mile Island, it was better, though there were multiple glarinig mistakes in operation and design that were obvous in retrospect. The ability to control the neutron input issue with a reluctant fusion process that has to be actively driven adds a layer of safety. But, with neutron magnification in the fissile material, and the tremendous amounts of heat produced by the short half life daughter products, how would a thorium breeder reactor compare with a LWR in terms of controlability margins and failure consequences?
[EDIT]Or another way of considering it, Is the fusion neutron production the only control that is needed, or are control rods a part of the picture? I assume the heat production comes from the various uranium isotopes and their daughter products that are bred. How fast would the heat output drop if the neutrons were turned off? If there was a cooling failure (and/or a control rod failure), could a meltdown occur?

I understand that they tried to shut down the Chernobyl reacter with control rods, but the ongoing breakdown of the daughter products continued to add heat till the large amount of cooling water in the reactor produced a large steam explosion. At least in Western reactors there is usually enough paranoia to include a robust containment shell about the reactor, though not always-
http://en.wikipedia.org/wiki/SL-1


Dan Tibbets

[Skipjack]

These always have been and still are the primary (but not the only) problems of nuclear power. I respect the fact that many people on this forum have come to the conclusion that nuclear power is the best answer to our energy problem. It would be nice if you could also acknowledge that there is a down side to nuclear power that has led some knowledgeable and rational people to come to a different conclusion. Belittling your opponents and their reservations is not a good way to find the technically and politically optimum solution.

Ok, maybe my wording was not wisely chosen. I am sorry. I just find that people are often waaaaay overreacting to the problems that nuclear power has. The storage of nuclear waste is IMHO a non issue. It is over exaggerated. Also, one can always refurbish it to some extent.

Accidents are also overrated. Yes Chernobyl was bad, so was 3 mile island. No question about it. BUT, but just because the deaths by coal power plants cant be counted as easily, it does not mean that they kill less people and I see much less resistance against them for some weird reason.
Chernobyl was human error. They purposely operated the reactor at its limits and then when catastrophy was near, they tried shutting it down instead of running it at full power, which would have prevented desaster. It was human error all arround. Plus, the reactor was a much inferior design in every aspect, especially in savety measures, to todays modern reactors.

The proliferation issue is a non issue. It is completely blown out of proportion. Having nuclear power is a right, that everyone should have.
I find it very, very funny that the US is the one crying wolf the loudest. After all the US is the ONLY country that has ever used nuclear weapons against an enemy (and still does not show any remorse about doing so).
It also gave its knowledge away freely to its allies, including Israel. Wonder what that was good for.
So really why do we even have to discuss this anymore?
Nuclear power is comparably clean, it is comparably safe. Proliferation is a non problem that is blown out of proportion for political reasons. "Non proliferation" is mostly a bunch of self righteous lies.

[Axil]

FYI:

http://www-formal.stanford.edu/jmc/prog ... nobyl.html

The Chernobyl accident occurred as a result of experimental use of a commercial reactor. This is crazy from the start.

Making an experiment with the reactor which involved disabling its safety features. This is the single main cause of the accident. The safety features would have safely shut down the reactor if they hadn't been disabled.

In order to prevent the reactor from shutting itself off from xenon poisoning, the operators pulled the control rods almost all the way out. This caused an enormous increase in the nuclear reaction to many times the reactor's normal power level...

[TallDave]

Yeah, those anti nuclear lobbyists. First it was the threat of radioactive waste, then accidents, now it is proliferation.
Never short of an excuse why we are supposed to not build nuclear reactors (or now even fusion reactors that do not even exist) to fullfill our energy needs.

First? Then? Now?
These always have been and still are the primary (but not the only) problems of nuclear power. I respect the fact that many people on this forum have come to the conclusion that nuclear power is the best answer to our energy problem. It would be nice if you could also acknowledge that there is a down side to nuclear power that has led some knowledgeable and rational people to come to a different conclusion. Belittling your opponents and their reservations is not a good way to find the technically and politically optimum solution.

My understanding is these aren't really serious concerns, at least not anymore. Nuclear waste isn't all that much more dangerous than other kinds of industrial waste, proliferation isn't a real concern in Western nuclear plants, and modern fault-tolerant nuclear designs make accidents less serious (obviously older designs like Chernobyl had serious issues).

I find it very, very funny that the US is the one crying wolf the loudest. After all the US is the ONLY country that has ever used nuclear weapons against an enemy (and still does not show any remorse about doing so).

I suppose we could have gone the full-scale invasion route instead, and killed even more people just so we weren't "the ONLY country that has ever used nuclear weapons against an enemy," but our gandparents, God bless them, just didn't see the point.

Anyways, have you met our left-liberals? They are very remorseful. Just ask them.

[Axil]

It, is not that I oppose fission power. It is that I am dismayed by the cavalier attitued of orgaanzations/ nations that provide nuclear plants to costomers whith no or little real control over innapropiate operation of the plant. Certainly, any nation capable of building their own plants could use them however they desired (assuming international penilties did not make it too uncomfortablte for them). But at least this would buffer somewhat the rogue use by otherwise limited nations or organizations, especially those who felt they had little to lose by employing weopenized nuclear material.

The difficulty of anticipating and planning for accidents is another issue. At Chernobyl this was obvously done poorly. At three Mile Island, it was better, though there were multiple glarinig mistakes in operation and design that were obvous in retrospect. The ability to control the neutron input issue with a reluctant fusion process that has to be actively driven adds a layer of safety. But, with neutron magnification in the fissile material, and the tremendous amounts of heat produced by the short half life daughter products, how would a thorium breeder reactor compare with a LWR in terms of controlability margins and failure consequences?
[EDIT]Or another way of considering it, Is the fusion neutron production the only control that is needed, or are control rods a part of the picture? I assume the heat production comes from the various uranium isotopes and their daughter products that are bred. How fast would the heat output drop if the neutrons were turned off? If there was a cooling failure (and/or a control rod failure), could a meltdown occur?

I understand that they tried to shut down the Chernobyl reacter with control rods, but the ongoing breakdown of the daughter products continued to add heat till the large amount of cooling water in the reactor produced a large steam explosion. At least in Western reactors there is usually enough paranoia to include a robust containment shell about the reactor, though not always-
http://en.wikipedia.org/wiki/SL-1


Dan Tibbets

It is that I am dismayed by the cavalier attitued of orgaanzations/ nations that provide nuclear plants to costomers whith no or little real control over innapropiate operation of the plant.

The latest policy thrust guiding the design of export reactors is to remove control of the fission process from the customer. The nuclear battery denies any possible access to the reactor or its fuel. It is also self regulating and does not provide any control or maintenance capability to the customer.


I prefer nuclear batteries that use thorium and U232/U233 in its reaction.

But, with neutron magnification in the fissile material, and the tremendous amounts of heat produced by the short half life daughter products, how would a thorium breeder reactor compare with a LWR in terms of controllability margins and failure consequences?

In a thorium fusion/fission hybrid, when overheated, its subcritical liquid blanket would automatically drain to a number of sub-critical storage tanks when a failsafe meltable drain plug disintegrates.

how would a thorium breeder reactor compare with a LWR in terms of controllability margins and failure consequences

These days, an LWR and a thorium breeder reactor are about the same in terms of its “negative void coefficient” behavior. No nuclear reactor is licensed unless it is melt down proof.


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


The liquid thorium reactor can’t melt down; it always operates in a liquid state. If some of the liquid blanket somehow gets out of the reactor, this liquid blanket just solidifies and stops the leak like puncture proof tire.

How fast would the heat output drop if the neutrons were turned off? If there was a cooling failure (and/or a control rod failure), could a meltdown occur?

The heat output would drop very slowly over a very long time frame. A meltdown could not occur. The liquid blanket would be in a storage tank until the cause of failure was found and fixed. When all was well again, the blanket would be pumped back into the reactor.

During maintenance, the storage tanks are used to clear the reactor.


Here is a good overview via video.

http://www.youtube.com/watch?v=WWUeBSoEnRk