Dirty Bombs

[Anthony]

The purpose of this thread is to discuss the best method for procuring the materials, building and deploying a "dirty bomb".

"Dirty bomb" is a bit of a media buzzword at the moment, and many people akin it to some kind of nuclear weapon, though it is not.

The construction is simple in theory, a radioative material dispersed by a HE device, or even a pyro composition - anything to get the material up into the air currents where it can be dispersed.

The first effect of a dirty bomb is the initial blast (if obvious) which may function like a regular "bomb". Throwing schrapnel, wounding/killing, destroying buildings/property and causing panick and hysteria.

The second effect, if the radioactive source is concentrated enough in the area which it is spread, is to cause "radiation sickness", which amongst other things cause burns on the skin.

Further effects are an increased risk of cancer amongst the people exposed to the event, and those who continue dwelling, or spending time in the contaminated area. The risk of cancer rises from negligble to extremely high, depending on the circumstances.

A dirty bomb will also cause *massive* hysteria amongst the population once news gets out about the bomb's nature. In Brazil, when a caesium chloride source was accidentally opened, barely anyone was contaminated, yet 10% of the city's population turned up at the hospitals demanding they be checked out. Despite being assured that they were at no risk. 10% doesn't sound so much, but it was over a million people! The dispersement of material was only slight and it wasn't a [engage hysteria] "terrorist" action.

The cleanup operation will be lengthy and extremely costly, in the meantime, the effected area will be uninhabitable. Afterwards, despite being clean, the area would probably be abandoned. The sheeple will be afraid of the nuclear bogeyman and the land and property will be worthless.

Imagine if this was the centre of a major or even capital city!

If the dispersing blast is an eventful one, the radioactivity will presumably be soon discovered. I'm not sure how it would be detected, doubtfully by the emergency services who first attend the scene. It's possible that if levels weren't high enough to cause radiation sickness that the source would never be discovered. Just marked off as another IRA car-bomb.

Sources scattered in non-dramatic ways would more likely never be discovered, such as being dispersed from a tall building.

Although depending on your motives, this may not be your wish. As outlined above, any dirty bomb will cause huge problems with hysteria, even if the contamination and associated risk is slight at worst.

Many radioactive sources would be useful for a dirty bomb, two immediately come to mind though:

Caesium 137:

A radioactive isotope of ceasium occurs naturally and is produced when uranium and plutonium absorb neutrons and undergo fission.

Half-life is approx. 30 years. It is a beta and gamma emitter.

19 metallic caesium 137 sources were stolen from a hospital in America a few years ago, where they were used as a radiation source used from radiotherapy. Despite a large scale search they were never found.

Due to it's physical nature, metallic caseium would be a poor choice for a dirty bomb. A fine powder is desired which will carry easily on the wind and thermal currents for many miles.

For this reason caesium 137 chloride would be a better choice, being a fine powder.

Some industrial uses for caseium are:

*moisture-density gauges, widely used in the construction industry.

*leveling gauges, used in industries to detect liquid flow in pipes and tanks.

*thickness gauges, for measuring thickness of sheet metal, paper, film and many other products.

*well-logging devices in the drilling industry to help characterize rock strata.

I'm not sure which of these source might utilise caesium chloride.

The source are plentiful though, they can be stolen from construction and industrial sites and often show up amongst scrap material.

A source of caseium chloride is the USSR. Where through a bizare obsession with everything radioactive, it was once used in "seed irradiators". Metalic drums with a funnel tops approx 3-4ft tall, which were intended to increase farming productivity as though it were some kind of comic book storyline. As a guesstimate, each irradiator should contain around 100gm of caseium chloride. The amount was described as being able to be held in your hands.

These and other sources lie scattered and abandoned about the former soviet empire.

Another suitable radioactive source is Strontium 90:

The half-life of Strontium 90 is 29 years and it is a beta emitter.

Strontium is taken up via the gastrointestinal tract and collects in bone tissue. The biological half-life for strontium in humans is a good 35 years, the effective half-life for Sr-90 is 15.6 years.

Maximum beta range in air: 10.62 m
Maximum beta range in water: 1.1 cm

Strontium 90 is chiefly used in Radioisotopic Thermoelectric Generators - a kind of nuclear battery which powers equipment. The decaying source provides heat to thermocouples which produce eletricty. Often used to power inacessible equipment such as light houses, oil rigs, weather stations, satelites or emergency equipment such as soviet radios.

Approx a thousand of these radio units were made un Russia during th cold war and almost all of them are unaccounted for.

Many seem to turn up in Georgia (not the state), cases exist where unshielded sources were discovered by fishermen. They took them to their camp to keep themselves warm during the night - the casing was approx 400*C. The next day the men were in hospital with most of their skin peeling off. The cleanup involved men handling the containers with 6ft pincers for no more than 40 seconds each.

"Based on the best information available, the current inventory shows that 134 Sr-90 RTGs have been manufactured. DOE has information on roughly 50 out of these 134 RTGs that are within the United States (That's 84 unaccounted for in the US).

These Sr-90 RTGs are located in seven states, including Alaska, Tennessee, Virginia, New Mexico, California, Texas and Washington.
The table below details the current known storage locations:

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">SITE RTG CUSTODIAN # OF RTGS

Richland, Washington U.S. Department of Energy-Richland 2

Oak Ridge, Tennessee Oak Ridge National Laboratory 6

Yorktown, Virginia United States Navy 22

Houston, Texas Nuclear Sources and Service Incorporated 4

Albuquerque, New Mexico Sandia National Laboratories 1

Burnt Mt, Alaska United States Air Force 10

La Jolla, California General Atomics 2

TOTAL
47</pre><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">RTGs have radioactivity ranging from 3,300-164,000 Curies (Ci), and there is one unit with 342,000 Ci. The average radioactivity of all units is 39,000 Ci.

The Air Force RTGs at Burnt Mountain include nine units with 53,500 Ci each and a tenth unit with 164,000 Ci.

The important thing - how big are the RTGs?

Sr-90 RTGs range in size. The RTGs owned by the Air Force in Burnt Mountain, Alaska are approximately two feet in diameter by three feet in height (about the size of a garbage can). Because of their housing and extensive shielding, these units weigh from one to two tons each.

Other Sr-90 RTGs range in height from 18-68 inches, in diameter from 14 to 52 inches, and weigh from 800 to almost 8000lbs.

Heavy... Stealing one wholesale might be difficult. It's possible that you might be able to rip out the source from the shielding, dump it into a lead-lined container and make away with just that.

It's largely presumed that the maker of a dirty bomb would die as a result. This isn't a problem for terrorists who have already shown a willingness to blow themselves up, or crash themselves in areoplanes into buildings. This would also be useful in removing a source from its shielding in order to steal it.

Death as a result of dirty bomb construction might not be inevitable though, if simple precautions such as keeping the source and finished device in a suitable lead lined container and away from your dwelling. Limiting handling time would also lower the risk, say no more than a couple of minutes per day. A good respirator would be useful when handling a powdered (desired) source. The filters should probably be changed after each "session". As they'd be holding the source near to your face, they should also be discarded carefully. I wonder what other precautions are within the reach of the "amateur"?

Various nuclear reactor waste may be useful as a source and probably isn't very well guarded or securely transported.

There's a lot points that could be discussed and I'm very interested in what everyone has to think!

[MrSamosa]

Have you considered raw Uranium Ore? I'm not sure how effective it would be, but there are countless Uranium mines in the South-West United States, many of them abandoned. While going into such abandoned mines is highly dangerous because of Radon accumulations, there is plenty of Uranium ore waiting outside of such mines for collectors and hobbyists; this is, at least, according to United Nuclear. Speaking of United Nuclear...they are also selling some Uranium ore. I am waiting for a "Super High Level" sample to come in before I buy some :D .

I'm not sure how dangerous the raw ore would be, but Uranium Hexafluoride is quite toxic, and it could be made from raw Uranium. In fact, Uranium Hexafluoride is an intermediate in the process of Uranium Enrichment. Unless I'm mistaken, I believe it is made using Hydrofluoric Acid.

I think anything with the word "Uranium" in it, which is quite well-known, will cause much more hysteria than something called "Caesium" or "Strontium."

As for dispersal, I imagine something similar to the first stage of a Fuel Air Explosion. Maybe the radioactive material would be dissolved in some volatile solvent, which in turn is spread by an explosion. The advantage of this is that when the solvent is spread, it evaporates quickly, leaving very fine particles of radioactive material, making it easier to inhale.

Is it possible to speed up Uranium's decomposition to Radon? I think dispersing a Radioactive Gas would be far easier than a solid.

<small>[ January 31, 2003, 10:55 PM: Message edited by: MrSamosa ]</small>

[nbk2000]

A copy of the "Los Alamos Primer" details the chemistry of uranium. Basically, you use acids to extract the uranium metal, convert to an oxide, then reduce with metallic calcium in an induction furnace to metallic uranium. You can react the metal or salt with gaseous HF to form UF6.

There's mountains of uranium mine tailings that could be used as raw material for bulk extraction. I also believe it's possible to use cyanide/urea heap leeching with molecular seive filtering to obtain highly concentrated solutions for processing.

I'd just use the oxide and use it in a pyrotechnic smoke mix to disperse radioactive uranium smoke into a crowd. The inhalation of radioactive uranium particles should ensure a rather spectacular increase in lung cancer rates for people in the area. :)

There's quite a few experimental reactors ran by industrial and university concerns that use sub-kilo amounts of weapons grade uranium and plutonium. With plutonium being on the same toxicity level as VX, with radiation hazard 1/1000th of that, it wouldn't take much effort to rob one of these places for their nuke material.

There's a WHOLE lot of radioactive waste in shallow waters of the northern ocean of the USSR. Some places have hard gamma waste in water as shallow as 16 feet! Enviromentalist groups seem to know a lot about where all the "good" waste is at, so I'd use them as a resource to figure out where to start trawling for rads.

Dioxin isn't radioactive, but seems to be rather easily made, certainly within reach of anyone capable of making advanced explosives. It's too easy to make, in fact, with many industrial processes having to take special precautions to avoid making it accidently.

This substance is extremely toxic to animals, though seemly of low toxicity to humans, capable of a "silent spring" scenario of birds dropping dead out of the sky and cattle keeling over dead in the fields. <img border="0" title="" alt="[Eek!]" src="eek.gif" />

Some herbicide plant in italy exploded, releasing only 6 pounds of dioxin waste, resulting in animal kills for a hundred kilometers downwind. :o

Imagine the panic in a city when dogs and cats fall over dead...birds dropping out of the sky, dead, onto crowded streets...doesn't take a genius to figure out how the sheeple would react... :D

I don't think limiting yourself to the popular image of a "dirty" bomb being strictly radioactive is productive. I would think the term "dirty" would be better used to describe a bomb used to disperse a long term enviromental hazard for the purpose and intent of denying the use of the contaminated area for extended periods of time, using non-conventional NBC materials, that may or may not be fatal to the people immediately exposed to it.

<small>[ January 31, 2003, 11:14 PM: Message edited by: nbk2000 ]</small>

[spydamonkee]

I recall a member talking about adding NaOH around an explosive device to create terror and panic from the burning, extreme pain & loss of sight that would follow.

dont know if it amounts upto a dirty bomb but i think it is still i good idea for those with limited time, budget etc

[darkdontay]

<a href="http://news.bbc.co.uk/2/hi/uk_news/2711645.stm" target="_blank">http://news.bbc.co.uk/2/hi/uk_news/2711645.stm</a>
*************
Friday, 31 January, 2003, 00:13 GMT
Al-Qaeda 'was making dirty bomb'

Government says its evidence proves dirty bomb threat
By Frank Gardner
BBC security correspondent

British officials have presented evidence which they claim shows that al-Qaeda had been trying to assemble radioactive material to build a so-called dirty bomb.
They have shown the BBC previously undisclosed material backing up their claim.
It includes secret intelligence from agents sent by Britain into al-Qaeda training camps in Afghanistan.
Posing as recruits, they blended in and reported back.
They revealed that Osama Bin Laden's weapons programme was further on than anyone thought.
British officials said on Thursday Bin Laden now had gained the expertise and possibly the materials to build a crude radioactive bomb.
The government says evidence suggests that by 1999, Bin Laden's priority was to develop a weapon of mass destruction.
He had acquired radioactive isotopes from the Taleban to do this, officials said, adding that development work on the "dirty bomb" had been going on in a nuclear laboratory in the Afghan city of Herat.

Evidence 'credible'

The government even has al-Qaeda training manuals which detail how to use a dirty bomb to maximum effect.
For a second opinion, the BBC showed some of the material to an expert on al-Qaeda.
"I think this is genuine," said Dr Mustafa Alani, of the Royal United Service Institute.
"It is credible. This is proof that al-Qaeda put a lot of effort into collecting information and educating other members of the organisation.
"It is possible to produce this sort of weapon."
British military personnel worked with intelligence officers to gather material which was taken to Porton Down defence research centre in Wiltshire.
Their conclusion was that al-Qaeda had a small dirty bomb but probably not a full blown nuclear device.

"From nuclear weapons the threat is very, very slim," said Gary Samore, a former US National Security Council member.
To create one, he said, al-Qaeda would have needed to obtain weapons grade nuclear material - a difficult prospect.
"On the other hand, the threat of a dirty bomb or radiological bomb, is much more plausible," he added.

British officials say the "bomb" has never been recovered but at least one leading al-Qaeda weapons expert from Herat is still at large.
Why the British government would release such top secret information has been questioned by some commentators in the Arabic world.
Abdel Bari Atwan, the editor of Al Quds al Arabi, said it was an attempt to revive fears in Britain and the US about 11 September.

"They would like to prove their point that there are links between Saddam Hussein and al- Qaeda," he said.

***********
They find eveidence about everything and anything, and everyone. Yet they had no knowledge and blind to 9/11. More bush lies to keep the fear rolling on home.

<small>[ February 01, 2003, 02:57 AM: Message edited by: darkdontay ]</small>

[Mr Cool]

MrSamosa: "I think anything with the word "Uranium" in it, which is quite well-known, will cause much more hysteria than something called "Caesium" or "Strontium.""

You're probably right although, as we well know, sheeple fear the unknown... "Seez-ium? I doesn't no wot that is - PANIK!!!"

There are also many abandoned uranium mines in Scotland and Cornwall for Brits. Search for (IIRC) "Dangerous laboratories" on google and you should find the relevant site. There are places where you can literally go with a geiger counter and come back with lbs of pitchblende if you do your research.

Lol, I was just thinking how anyone monitoring my mail would be extremely suspicious right now... I've been getting chemicals, which no good sheep should be interested in, and recently a geiger counter... let's hope they don't come and kill me :(.

"Is it possible to speed up Uranium's decomposition to Radon? I think dispersing a Radioactive Gas would be far easier than a solid."

No. Although it'd be fun if you could speed up radioactive decay. Imagine if you could make it instantaneous, then any radioactive material could be made into a nuclear bomb because instead of the energy being released over thousands, millions or billions of years it could be released in milliseconds...
But sadly it's not possible yet, and probably never will be.

[Flake2m]

If you can make Dioxin then you could actually target specific industries.

Lets say theres a chemist working a chemical plant. He gets fired becuase of job cuts. He could get revenge on the chemical plant by manufacturing Dioxin and then dumping it in a river or around the chemical plant. Chemical plant gets blamed.

"There will be a silent spring"
Iraqi Desolator - RA2

[VX]

Also MrSamosa, radon gas would be far less effective as a persistent threat as it would be too finely dispersed within seconds to have any effect. Nobody would ever know that it was ever there. The whole point is that the radioactive material stays around for 'ever', if a gas is used this would clearly not be the case.

Also in the UK there has been massive coverage on the news etc about a ricin manufacturing lab being discovered. Nobody I have spoken to had ever heard of ricin before its recent publicity, but they still fear it now. So I think that using less well known radioactive elements would cause an equal amount of fear as U, Pu etc. An interesting fact about uranium is that it is hardly radioactive at all! United Nuclear were at one point selling Uranium oxide fuel pellets, and they claimed that because they were so highly pure that they were less radioactive that their 'low level' samples.

Perhaps a highly toxic compound could be made using radioactive isotopes of one of its constituent elements. Easy examples would be to use radioactive isotopes of Carbon and Nitrogen. Are their any particularly toxic (organic) compounds containing strontium, cesium, uranium, etc?? This would be a double threat, truly evil!! :D

[MrSamosa]

Despite its low toxicity compared to Strontium-90 or Plutonium even, Uranium still has use as an areal-denial weapon. One must consider that rescue workers like to err on the safe side. That is to say, that should they detect even minute amounts of radiation, they will barricade the area for some time to come until it is thoroughly cleaned.

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica">I'd just use the oxide and use it in a pyrotechnic smoke mix to disperse radioactive uranium smoke into a crowd. The inhalation of radioactive uranium particles should ensure a rather spectacular increase in lung cancer rates for people in the area.</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">Let's not forget that Uranium Oxide, when very dry, is quite pyrophoric. As such, I can see use for it in a pyrophoric-ignited Fuel Air Explosion. The fuel will cause the expected overpressure and burns, while the Uranium will leave residual radiation. I like the idea of making FAE's look as much like a tactical nuclear explosion as possible.

[nbk2000]

One would also want to use disinformation in conjunction with the weapons to increase the psychological effect.

If the UO was able to be used in the manner of a thermobaric/FAE, and was actually effective in destruction, than a little "conspiracy theory" campaign via e-mail, newsgroups, etc could be used to say that it wasn't a "dirty" bomb, but an improvised nuke that fizzled, and that's why it's got so much uranium contamination with such an intense blast effect. <img border="0" title="" alt="[Wink]" src="wink.gif" />

The gubernment would deny it, of course, which would just feed the conspiracy theory even more. All you'd need would be a well placed "leak" to lend credence to the "fizzle nuke" story, and it'd greatly increase the fear since the terr-or-ists would now have nukes, rather than just simple "dirty" bombs. :D

[EP]

An analysis of a "dirty bomb" going off done by FAS:
<a href="http://www.fas.org/faspir/2002/v55n2/dirtybomb.htm" target="_blank">http://www.fas.org/faspir/2002/v55n2/dirtybomb.htm</a>

[Jhonbus]

Another isotope to consider would be Americium 241. It has a fairly long half-life of about 450 years so it isn't very strongly radioactive, but its main benefit is that it is extremely easy to come by, given that it is used in many smoke detectors.
I think the best (worst!) type of source for a dirty bomb is an alpha emitter. Simple fact is that you are not really going to cause much damage by exposing people from outside their bodies. If you want to do this you have to use gamma rays really, alpha particles are stopped by a few cm of air, or the very outermost layer of skin, and will cause no damage. Beta particles won't cause much damage as they too will hardly penetrate skin. Gamma rays will penetrate skin, but they will also tend to go straight through a person, so will also cause little damage.
This means the way to cause damage is to ensure emitters are taken into the body. Then to use Alpha and beta emitters as these particles will be absorbed by the tissues. Thirdly, once inside the body, Alpha particles are the most damaging as they have a relative biological effectiveness (RBE) of 10, compared to the RBE of 1 beta and gamma have. In simple terms this means they cause 10x the damage per amount of energy lost by the particle.
241Am is an alpha emitter, so is ideal for this application. It should be particulised by fire or whatever, so it is inhaled. This would cause a large number of lung cancers, and probably radiation sickness too.
An interesting consideration would be fast neutrons. These are thermalised by the hydrogen molecules in the water of the body, releasing huge amounts of energy. The neutrons are then captured by atoms in the body, nearly always making that atom radioactive. Fast neutrons have an RBE of about 15. However it is very difficult to produce them. It usually requires nuclear fusion.
Thermal neutrons can be produced by irradiating certain materials such as berylium with alpha particles, IIRC. However this wouldn't really be usable as a weapon. Thermal neutrons also don't really have a very high RBE, though they do have the capability of making other materials radioactive, which alpha, beta and gamma cannot do.

<small>[ February 05, 2003, 10:03 AM: Message edited by: Jhonbus ]</small>

[MrSamosa]

While Am-241 may seem like a good choice at first because it is available in common smoke detectors, there is one important problem with it. It is incredibly expensive- $1,500/gram, to be specific! And one gram is enough to make 5,000 smoke detectors. That means you need to count 5,000 smoke detectors for just 1 gram of Am-241 :( .

[Jhonbus]

That's a shame!
Well Alpha emitters are still the way to go, if you can find one that is easy to get in large enough amounts.

[Mr Cool]

To be effective, many Curies would be needed.
Alpha sources of this size do not seem to be very common, as they are not used for medical purposes and therefore could not be found in scrap yards etc.
Anything that uses radiation to get hot would be good, as these would necessarily contain huge amounts of source material. Most use fission by-products such as Sr-90 or Cs-137, but some nuclear batteries contain Pu-238 or even Po-210, alpha emitters. These tend to be for space applications, and are therefore not common (and you would need to find the Po-210 ones quick!)...
Although don't sea buoys occaisionally use nuclear batteries in some circumstances..?

[Anthony]

Indeed they do, bouys, light houses, remote weather stations. Lots of remote applications, good thing about remote is there's no one around to see you stealing them :)

[Sarevok]

Perhaps Uranium can be extracted from a mineral (it's less suspicious to buy a mineral than to steal radioactive material from hospitals and the like) and used as the radioactive material that the dirty bomb will spread. I found this:

Uranium Extraction and Chemical Analysis

Apatite material (...) was washed with an aqua regia solution (mixture of hydrochloric acid and nitric acid at a 3:1 ratio) to extract uranium. The procedure is described in the following.

1. Mix 750 mL of concentrated hydrochloric acid (HCl) with 250 mL of concentrated nitric acid(HNO₃) in a large pyrex beaker. Pour the HNO₃ slowly into the beaker containing the HCl.

2. Allow the aqua regia mixture to cool before using.

3. Weigh quantitatively one gram of the (...) (apatite) and place into a Teflon beaker.

4. Add 50 mL of aqua regia to the Teflon beaker.

5. Turn on the hot plate and place the beaker onto the hot plate.

6. Do not allow the acid to boil and spatter. Apply heat gradually and check the solution to ensureit does not spatter.

7. Leave beaker on the hot plate for two hours. Continually check the solution to ensure it does not go dry.

8. Add aqua regia in 10 mL increments if solution is approaching dryness.

9. After two hours, turn off the hot plate and allow the sample to cool.

10. Transfer the entire sample into a centrifuge tube using 5 mL deionized water.

11. Place the tube in a centrifuge and spin down at 3000 rpm for 10 minutes.

12. Pour and collect the supernatent into a separate container.

13. It is very important to measure the final volume of solution. Bring the supernatent up to 40 mL with deionized water.

<a href="http://www.wsu.edu/swwrc/Flurys~2.pdf" target="_blank">Source</a>

I don't have apatites to try this and I don't have enough knowledge to say if this works or no. Someone have any idea about the above process? It's possible to extract uranium from apatites using this method?

<small>[ February 22, 2003, 12:07 AM: Message edited by: Sarevok ]</small>

[VX]

It probably is possible.

However Uranium would make a poor choice for any 'dirty' bomb. This is because it's main isotope (238U) has a half life of 4.5 billion years..... Hence it is virtually non radioactive.

In addition there is no advantage to using elemental isotopes over compounds of the elements, as the radioactivity remains the same regardless of the environment of the nucleus. So it seems a pointless task to extract the Uranium.

[James]

IIRC Unrefined Uranian is roughly 90% U238, roughly ~9% U234 and less than 1% U235. However it has been some years since I read this so I may be misremembering. However the thought occurs to me that if a steady neutron source can be obtained, You can for more interesting isotopes. You should probably put a neutron reflector around the setup to increase yeild/foil detectors.

[VX]

Natural Uranium is about 99.27% U238, and about 0.72% U235, and a tiny (0.0055%) amount of U234.

From <a href="http://hps.org/publicinformation/ate/q702.html" target="_blank">here</a>

[Sarevok]

MrSamosa is right:

Americium oxide, ²⁴¹AmO₂, was first offered for sale by the US Atomic Energy Commission in 1962 and the price of US$ 1500 per gram has remained virtually unchanged since. <img border="0" title="" alt="[Eek!]" src="eek.gif" />
One gram of americium oxide provides enough active material for more than 5000 household smoke detectors. :(

<a href="http://www.uic.com.au/nip35.htm" target="_blank">Source</a>

Uranium won't work, Americium is more expensive than gold, Caesium must be stolen from a hospital (so, before you finish the dirty bomb you will be jailed and ass raped, as nbk2000 says) and Strontium:

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica">Sr-90 RTGs range in height from 18-68 inches, in diameter from 14 to 52 inches, and weight from 800 to almost 8000lbs.
</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">I give up. Let's do some Acetone Peroxide...

<small>[ February 22, 2003, 01:01 AM: Message edited by: Sarevok ]</small>

[metafractal]

I think the conclusino to be made from this discussion is that it is incredibly difficult to make a dirty bomb as an effective, lethal weapon. However, as stated earlier, one could be incredibly effective as a weapon to destroy the population (and therefore all industry) of a given area. Do you think that 80 year old Ms Lindool Fuckwit Sheepwoman III would think twice about leaving Idiotville that second after she hears that a 'terrorist attacked a shopping center only 10 miles from Idiotville with an explosive device that dispersed radioactive uranium'? The media will love every bit of it, and be a great service to you, constantly ranting & exaggerating the (non existant) life threatening effects. Hell, you could even use depleted uranium, and I think it would still have the same effect (terror)!
I think this use for a dirty bomb have been vastly underestimated; can you imagine how even a superpower could be seriously crippled if you strategically target its places of concentrated cultural/industrial/economic power? Panicking people are uncontrollable, thereby temporarily kicking the country in the nuts. In the postmodern hell we live in, to the masses, things, events, and everything else, are what they represent, or what people think (i.e. have been told to think) they are, rather than what they actually are (i.e. their reality, use, etc.)

Anyway, concerning the use of a dirty bomb for its actual radiation poisoning effect, while I was searching for a viable source of cheap, obtainable radioactive material I had the idea of obtaining caesium from a hospital by actually being perscribed it. While the actual material given to you through the perscription would be in minute quantities and bareley useful, it could reveal key information about it allowing you to obtain it by some other means. An established doctor may have no trouble stealing some, especially if he steals small amounts from many hospitals. Too bad though, its main use is for... wait for it.... GYNACOLOGICAL CANCER!
Anyway, if you were really serious about it, for usefull radioactive material I think that you'd have a much better chance finding it in the east (i.e. chiana, or war torn chaotic nuclear playground 3rd world country) than the west. The problem is getting it back to where you want to use it. Nonetheless, I dont think that airport security is anywhere close to as infallible as they would have you believe.

P.S.
Wait, I've got the perfect material to use for a dirty bomb. Why not use FRANCIUM!!! <img border="0" title="" alt="[Wink]" src="wink.gif" /> It seems to be everywhere these days, I've got so much lying around the house I can bareley clean it all up!! :p <img border="0" title="" alt="[Wink]" src="wink.gif" /> :p .

<small>[ February 22, 2003, 07:31 AM: Message edited by: metafractal ]</small>

[rjche]

My understanding of dirty bomb whether it be radioactive, or pcbs, or lead, asbestos, or some other material demonized by the government scarecrows, is not in the damage it does to people, but its clean up cost. The public reacts hysterically to any chem spill, so to disrupt economy, cause pain and suffering to an enemy, etc. one does not have to be exotic.

Radio active is radioactive to the ignorant public. Hell many even believe radiation from a microwave is the same as that from nukes.

To get an idea just watch the hysteria of local haz mat crews if one spills diesel fuel on the road. I recall a large pcb transformer fell off a truck in the SE, and spilled many gallons of its oil on the roadside. Danged if they didn't dig up the whole area and haul it to a site, and rebuilt a section of the highway. Thats for a few gallons spilled there. But that river that goes by the GE plant that made pyranol in NY has tons of it lying in the bottom sediment and its ignored although many cities drink that water. It would cost too much to dig up that river so the govt just pretends not to see that, and the news has not been mentioned by local press lest it cause economic disaster.

Throwing a fake grenade into a crowd does almost as much damage as a real one. People go ape when they see anything that triggers the hysteria planted in them by media publishing stupid exaggerations made by government's in high great for some attention.

People going ape are as dangerous as shrapnel, poisons, and other stuff. Getting trampled by a few couch potato welfare queens whose stampeding foot area pressure can cause cracks in sidewalk blocks, is more disabling than most chemical warfare agents.

[spydamonkee]

For a really cheap & easy terror creating "dirty bomb" I really do think a few kg's of APAN used to spread many kg's of NaOH & mayb even abspestos among other nasties mixed in.

It would easily cause mass terror, hysterics and confusion

Edited a stupid spelling mistake <img border="0" title="" alt="[Frown]" src="frown.gif" />

<small>[ February 23, 2003, 05:37 PM: Message edited by: spydamonkee ]</small>

[Sarevok]

The dioxin is perhaps the most viable idea. I've done some reading in <a href="http://www.eurochlor.org" target="_blank">Chlorine Online</a>.

The texts says that there are many types of dioxins, the most dangerous is the 2, 3, 7, 8, Tetrachloro-Dibenzodioxin.

They have useful characteristics (for the dirty bomb):
Dioxins are slow to evaporate (i.e. they have a low vapour pressure), do not dissolve readily in water, but are lipophilic (or fat-loving) that is, soluble in fatty substances and in organic matter with fat-like properties. Dioxins do not react easily with other chemicals. These characteristics explain why dioxins are usually found adhered to or dissolved in fatty tissue where they can (bio)accumulate. In lakes and rivers, dioxins are often detected bound to sediment or other organic substances.

Reading about unwanted dioxin formation in industries I found how they are made: Chlorine, Oxygen, Hydrogen and Carbon reacts to form dioxins. The reaction happens between 250°C to 500°C and it is catalyzed by CuCl₂.

<small>[ February 23, 2003, 08:46 AM: Message edited by: Sarevok ]</small>

[Machiavelli]

The term 'dirty bomb' is used to describe a radiological weapon that kills or damages through radioactivity but without a nuclear explosion.
If you want to discuss the issue of toxic warfare, please open up a new thread for it, otherwise everything gets mixed up, it's hard to find stuff and I can't execute kewls for not doing a proper search before posting :)

[Anthony]

An un-named oil company in Nigeria has just admitted the loss of a quantity of radioactive metal...

[Sarevok]

Posted by Machiavelli:
</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica">The term 'dirty bomb' is used to describe a radiological weapon that kills or damages through radioactivity but without a nuclear explosion.
If you want to discuss the issue of toxic warfare, please open up a new thread for it, otherwise everything gets mixed up, it's hard to find stuff and I can't execute kewls for not doing a proper search before posting</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">Posted by nbk2000:
</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica">I don't think limiting yourself to the popular image of a "dirty" bomb being strictly radioactive is productive. I would think the term "dirty" would be better used to describe a bomb used to disperse a long term enviromental hazard for the purpose and intent of denying the use of the contaminated area for extended periods of time, using non-conventional NBC materials, that may or may not be fatal to the people immediately exposed to it.</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">

[NightStalker]

NOVA (in US) is going to have an episode about dirty bombs on tuesday night. Someone may wish to record it for upload to the FTP. :)

[Machiavelli]

The thing is that the problems connected to aquiring/preparing and using radioactive materials are rather unique to this substance class, while the chemical stuff suits itself better to a discussion of 'toxic warfare' (Which was recently covered in a nice RAND study btw).

[VX]

United nuclear have a section in their 'dangerous projects
& fun experiments' section a topic entitled 'Build a Particle Accelerator'. The only problem being it isn't up yet, but when it is I will probably be making one.

If someone was so inclined they could make a large one and leave it on for a while to created comparatively large amounts of radioactive isotopes.

Does anyone have any simple plans for making a linear accelerator?

[Mr Cool]

Simple linacs are easy. I read an article on making one, it was like the Scientific American articles but I don't think it was from there... it was in a big book, maybe it was a compilation of SciAm articles. It had all sorts of cool things in.
Anyway, the Linac was, essentially, an evacuated glass tube, perhaps a foot or two long. At one end was a filament (used if you wanted to accelerate electrons I guess, otherwise a plain electrode would do). The other end was sealed with Al foil, supported by an Al grid. On the outside of the tube, at regular intervals, were perhaps ten or fifteen wire rings. These were formed by wrapping lengths of wire around the tube, and twisting the ends together. All the twisted ends of the rings were then aligned so that they pointed to each other. This, IIRC, helped to create a more even potential gradient along the tube, by corona discharge I think.
The sample to be irradiated was placed near the Al foil that functioned as one electrode.
If an electron beam was desired, the filament would be heated an made -ve by 500-1000kV, and the Al foil would be grounded.
For other particles, a small amount of gas was allowed to remain in the tube - hydrogen for protons, deuterium for deuterons, for example (I suppose He would work for alphas, but you might get 1+ ions..?). The filament then would be +ve (no heating), and the Al foil -ve in relation to it (actually grounded, I think). They claimed succes at transmuting Li to Be, IIRC. They used VDG's to create the pd, a Cockroft-Walton voltage multiplier would be better since we have the luxury of HV diodes. Also it makes polymers harder and raises their mp's by forming cross-links.
I think, though, that you would need a very big one to get useful amounts of radioisotopes! And the transmutations that you could perform would be limited by the accelerating pd that you could obtain, which would probably have a limit of 1MV max.

Try to find the article, it was quite interesting. And I',m sure with modern materials it would be a lot simpler to produce.

[A43tg37]

I don't really know if this belongs here or in a new topic, but if igured I'd put it here first...if this needs to be in a new topic, please move it.

Check this out:

<a href="http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3210094561&category=413" target="_blank">http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3210094561&category=413</a>

All of this talk about uranium and United nuclear got me to serach on Ebay for uranium ores, and I found this....this rock measures 650,000 CPM (more than 6 TIMES as hot as the hottest ever offered by United Nuclear). It's a mixture of uranium ores, and at that high of a radiation level, undoubtedly contains small quantities of radium and thorium as well. The "buy it now" price is too rich for my blood, and the people bidding on it are using an auction stealer (they were the last time it was up for bid anyway), but it's certainly worth bidding on if you have the cash...hell, at that radiation level, one has to wonder how much refining it would need to be put in a "dirty bomb".

Oh, and BTW this is NOT a plug for me (I'm not the guy selling it) or for him, or intended as advertising in any way...I just thought it was worth mentioning in a thread that covered good high level sources of radioactivity.

[firebreether]

A decent sized radium source can be at least as hot, and much cheaper than any uranium ores. Keep in mind that this is alot of uranium, typical sources will be 10,000 - 50,000 CPM depending on the ore.

I think transmutation isnt really an effective way to produce any radioisotopes in quantities large enough for any effective dirty bomb. If you want quantity, stealing has got to be the way to go.

Fear is a terrific weapon in itself though, so just dispersing uranium over a township will be definitely blown out of proportion by the media, and will cause fear.

[VX]

It has been proven over time that a bomb does not need to blow up to cause fear/ chaos etc.

A relatively small explosive device, arranged in such a way that if the bomb did go off would spread a relatively small amount of radioactive material could be equally effective at causing the sheeple to completely overreact. ..... So long as it didn't go off. Especially if it was 'found' at a school/ football game etc.

Let me be clear, the 'bomb' would be planted and left. It must be perfectly capable of blowing up, however one would then proceed to ring the police/ tabloid papers etc and tip them off. (Who’s seen Die Hard with A Vengence? :D ) The bomb would be safely disposed of without blowing up (hence without proving to the general public that is was small and harmless) And the TV, newspapers etc would make the problem sound a million times worse than even a good bomb could have done! No matter what the police/ experts said about it being harmless people will not believe it. The fact would remain.... a 'dirty bomb' would have been found. The people who matter (the people who make the news) would simply not care how dangerous it really was, they would have the best story in the world..... Along with the power to cause mass hysteria (and sell papers)

It would of course be far scarier to realise that 'terrorists' have the materials to do this sort of thing and are willing to, than for it to just happen one day (especially if the bomb was not very good anyway). People would have time to think about it and become worried.

[cutefix]

I think the USA is the foremost promoter of dirty bombs.
Dirty Bombs?
Look at their wanton use of depleted uranium by the US and its
allies . It was even blamed as one of the cause of the Gulf WAr syndrome as more than 300 tons of depleted uranium were used during the Gulf War.
Now as their is a possibility of another war with Iraq and the US is supposedly stacking large amounts of uranium rich weapons that is even present in 2000 lbs GBU unit which are designed to penetrate highly reinforced bunkers.Depleted uranium is dirt cheap if compared to tungsten.Check it on the issue of wired news dated
02:00 AM Mar. 10, 2003 PT
and more info about these uranium bombs.

[Energy84]

VX, you are absolutely right. What you described actually happened in my school this week.
On tuesday we were evacuated and sent home because one of the janitors found a 'suspicious package' in one of the washrooms. It turned out that some kid stashed his firecrackers in there. :rolleyes:
Then yesterday (wednesday), someone called in a bomb threat and of course everybody panicked and once again evacuated the whole school.
Finally today, only half the students showed up and going to class was not mandatory.
Needless to say, people were scared shitless that a 'bomb' was found in the school. It turned out to be those triangle firecrackers from what I heard... :rolleyes:

[megalomania]

I once slapped a radiation warning sticker on the box my Israeli gas mask came in (complete with Arabic type writing), sealed it up with a brick inside and dropped it at someones front door. I bet that would go over a lot better nowadays :D

[Chade]

Mr Cool:
'it'd be fun if you could speed up radioactive decay. Imagine if you could make it instantaneous'
This is sorta possible. For example, natural Uranium 235 fission is triggered by slow neutrons colliding with the atoms. You can speed it up by adding neutrons. As each decay gives out three neutrons, you can just pile more U 235 together, to increase the decay rate. When you get to 15 kg of pure (enriched) U235, you speed up the decay rate, and make it happen (more or less) instantaneously. I've seen film of someone doing this over a little town called Hiroshima.

The Nagasaki bomb (fat man) used Plutonium 239, and was a bit more powerful. But these are a little over the top for dirty bombs.

So, how to get a radioactive materaial? You've got two choices which boil down to finding it, or making it. Hands up if you've heard of David Hahn. He was a boy scout who went a little bit over the top when applying for his atomic energy badge. He made a fast breeder nuclear reactor in his shed. No I'm not kidding, but it's easier than it sounds. I first heard about this guy from some friends of mine (who are physics PHD students, so they know what they're talking about) and later caught a half hour program about him. I recorded it, and btw, any program that included the phrase 'We will show you, step-by-step, exactly how he did it, but please don't try this at home' has got to be worth recording.

These steps are 'how-to'. I don't have the theory, but I might research it when I get a moment.

Step one was enriching Thorium. He took thorium lantern mantles, which are apparantly still available in some places in the USA, and definately on Ebay. You blowtorch these down to a powder, bundle this with some Lithium from Lithium batteries, and wrap in aluminum foil. You heat this in cooking oil to get pure thorium 232. Like I said, fairly vague instructions, but it looked like a teaspoon of powder with the Li from one battery. The powder started out white, and ended up black. It didn't seem to have reacted with the foil. Thorium will decay into plutonium and uranium.

Step two was building a neutron gun. Now a neutron source will make many other materials radioactive, so it's pretty useful. David, it should be noted, spent vast amounts of pocket money on old radium watches and smoke detectors. A shop near me sells smoke detectors at £4 a pop. Anyone beat that? OK, here's how the neutron gun works. When alpha particles (that's the nucleus of a helium atom) hits aluminum foil, it emits neutrons. Yes alpha particles can make neutrons that easily, and then they can make most other elements radioactive. So take a lead cubic box with walls 1mm thick and 15cm each side. Fill it with as much Smoke detector Actinium as you can get your tongs on, and duct tape it shut. Make a hole in the side and tape aluminum over the hole, so the alpha rays pass through the foil only. The Alpha radiation will be stopped by the foil, but the neutron radiation will pass out the other side and irradiate whatever you put in the way. In the show, they put a penny in front of the gap, to make it radioactive. This will only be as radioactive as your source, which will likely be weak. But you should be able to make small items radioactive enough that your own geiger counter will register it.

If you're concerned about getting noticed, you can buy geiger counters OTC from electronics stores, or get them in kit form. If you fancy a challange, there are instructions on the net for building your own. http://www.rhunt.f9.co.uk/Electronics/Geiger/Geiger_Page1.htm amongst other places. Do watch those voltages though. I made mine, powered by a 9V battery, turned it on, and shocked myself from the rectifier circuit (200V DC). I promptly dropped the counter, and after about a tenth of a second thought 'oh, no, I've broken it'. Picked it up, and damned if I didn't get shocked again. How's that for a stupid move?

Davids' step three was extracting Radium from clocks by dissolving it in a solvent to remove the paint. Didn't say what solvent, but I'm guessing most forumites will have a few to try. Also Radium paint glows like buggery, and it's not often you get to see if an extraction has worked by the fact you've now got a bowl full of glowing green liquid. Very pretty chemistry. The cool thing was where he got his first clock. When old enough to drive, he strapped a geiger counter to his car and drove around clocking the radioactivity. He got a peak by an old antique shop, and followed it inside, to find an old radium clock. This does flag how easy it is to detect this stuff. If you don't want it detected, wrap it in Lead until you can't tell it's there with the most powerful geiger counter you can lay your hands on. Radiation follws an inverse square law which means if you detect 4clicks per second when you're a metre away, you'll only detect one click per second at two metres. (units not important here) Wrap it up so you cant detect it, then you're safe, and can be pretty sure you won't be found out unless someone's looking for you.

Step four was building the reactor. The core was americium and radium wrapped in Al foil as a 3-4cm diameter sphere. This was surrounded by thorium cubes made by mixing thorium and charcoal and tamping down to 5cm cubes. Nine cubes, 3X3, then eight cubes on top of that (missing out the middle one) and eight more cubes on that. (this is a lot of gas mantles, but hell, we're making a fast breeder reactor here!) Pop your core in the center and add a final cube on the top, sealing the whole thing with duct tape. Poke two Cobalt drill bits into the middle alongside the core to act as control rods, and there you have it. It will sit there making Plutonium.

The end of the story. David noticed his reactor was getting out of control, so he figured he'd get it the hell out of there. (after cacking his pants, I imagine) He put it in his boot and drove away. He got stopped after a half mile by the police, and had to explain his situation. shortly thereafter, men in protective suits came and took his shed away, and buried it in drums under the nevada desert. He was never charged with any offence, as they said he hadn't broken any laws. (not sure if that'd still apply?) Apparantly, he's now in the navy. On a nuclear sub.
Oh yes.

Personally, being a physicist, and not a chemist, I'd make my radioactive sources myself. Mr Cool is also dead right to say that linear particle accelerators are easy to make. Most people have them lying around the house anyway. Cathode ray tubes in Televisions accelerate electrons towards the screen until they hit a phosphorescent material, and they do it reliably, for many years. Hack one apart, and play with it a bit. Watch out for the high voltages on the capacitors and the back plate behind the tube though. They can hold lethal voltages a long time after they're off. We wouldn't want to do anything dangerous now, eh? I'm in the process of doing this at the moment, and it can provide a beta source which will last, not just years, but essentailly a life time.
Now what is needed is a materal that will absorb beta radiation to give out alpha, or neutron radiation. It's possible this could even be done with trial and error, since it's only the elements you'd have to test. Alpha + Aluminum gives neutron radiation, so once you find a suitable material, you can produce radioactive materials, only limited by the strength of your cathode beam. You could up this by using Mr Cools accelerator. I've also got instructions somewhere from an old old book on making your own synchrotron. That'd do the buisness. I'll try and dig that book out actually. It's a later edition of a book that actually removed a chapter on how to do vivisection on animals, because the authour was a mite concerned that readers seemed to like trying it out.

The neat thing is that no-one seems to care what you do with physics, compared to chemistry. It gets so much easier to buy the stuff you need, and even ask about it. Tell someone you're building a synchrotron. Most people will just say 'Mmmm, really...' and change the subject before you start talking about physics.

[Anthony]

I believe the guy organised with a smoke detector manufacturer to buy broken detectors by the kilo.

[alpha1991]

Anybody know a decent formula for dioxin?

Have tried to synthesise before but no luck.:(

[bobo]

Dioxin is a group of compounds, not a singular one. Read a bit about it before even thinking about making such crap.

For example:
http://www.ejnet.org/dioxin/

[kingspaz]

alpha1991, you're a fucking retard. dioxins aren't radioactive so why the fuck post in the 'dirty bomb' thread? if you don't know what dioxins are how the fuck are you going to synthesise any?

[TreverSlyFox]

Now I don't know anything about radioactive materials but my former occupation let me see the effects of fear and panic in sheeple in a non-radioactive enviroment. The average joe will panic in most situations in which he knows very little about whats going on, but just knows it's BAD and it might get him. The bomb would have to contain enough radioactive material for the average news reporter to get his hands on a giger counter and have it start clicking. From that point on the media would be using "sound bites" and "hot words" in their reporting of the "Nuclear Incident", "Dirty Bomb" and "Terrorist Attack".

It wouldn't make one wit of difference what the level of radioactivity was just as long as a reading could be taken. A special edition of the major news papers would be published and every media net work would break programing to report it for the next week at least. The sheeple would be scared shitless and the majority within 50-100 miles would panic. Their greatest fear, fed by the recent publisity on "dirty bombs" would be the straw that broke the camels back.

After 9-11 the sheeple are waiting for the other shoe to fall and this would be a boot. Set it off in a major financial center or industry town and it would be dead in a week, the stock market would drop again and the economy wouldl take a nose dive. There would be such a public outcry that the city would have to be leveled and carted off to a hazaredous waste facility. The sheeple will only need two words to set them off "NUCLEAR" and "TERRORIST"!

The media has already done most of the leg work to start the panic, all it would take is the incident to set the whole thing in motion. One little thought in closing. What would it take to contaminate a towns water supply with a radioactive material, just enough to get a reading? Maybe you wouldn't take a dirty bomb at all.

[nbk2000]

TreverSlyFox, stop putting the "Trever" at the bottom of your posts. This is not only annoying, but a violation of The Rules.

Anyways, if the definition of "Terrorist" is someone who inspires fear in people, than that should make the media the biggest terrorists of them all, since they can get millions of people terrorized in just minutes. :D

I would include Dioxin in the definition of a dirty bomb, since it would contaminate an area with the intent of rendering it uninhabitable, but that's just me.

[WTF]

I wonder if it would be easyer to obtain some weapons grade plutonium or U235 that other radioactive materials, because there is so much of the stuff sitting around in nuclear bombs, and everything is for sale in the ex-soviet union (especially the breakoff states that have no money)

If it was possible to obtain some then it is straight forward to make a nuclear bomb (Read "The Making of the Atomic Bomb,by Richard Rhodes), though if the nuke fizzles, it still will take out several city blocks, irradiate the general area and cause mass panic (and of course for a terrorist that's the whole objective)

[kingspaz]

thats an interesting idea but would likely require big funding to obtain the isotopes. a fizzling nuclear bomb would make for one hell of a dirty bomb. it would be the ultimate dirty bomb as far as i can see.

[WTF]

I think if you wanted to make a "fizzle" nuke, rather than the fullscale explosion, it would easyer to make, just take two chunks of plutonium, at less than critical mass, but grater than combined, and then make a mechanism to stick them together. When the two chunks got close enough together, a chain reaction would start and the plutonium would melt (and make a hell of a lot of radioactive isotopes, neutrons, etc). Coupled with a good old conventional explosive one could irradiate a very large area (depending on wind direction, strength).

Personaly, if i went to the trouble of aquiring plutonium, and if I was a terrorist, I would go for the fullscale explosion.

I have done some research on the internet on the toxicity of plutonium, and it seems that it being the "most deadly substance on earth" (as in toxicity) was a myth. Yes it is radioactive, but it is mostly an alpha emitter, which is almost harmless (it won't penetrate the skin). It also causes cancer if inhaled, but only after many years.

[streety]

WTF, if you had enough plutonium to make a nuclear bomb fizzle you could make an efficient nuke for not much more effort. I would have thought a fizzling nuke would involve bombarding a subcritical mass of uranium or plutonium with neutrons. This would lead to the reaction starting but being unable to go to completion, hence fizzling.

Another idea, although i'm not sure if it woud work might be to use hafnium-174 (not sure on the atomic number but I think this is right) If you bombard this with X-rays (relatively easy to make) it decays, releasing large amounts of gamma rays. The reason i'm not sure if this would work is because I don't think this is a self-sustaining process. However if it did work it would lead to a massive amount of radiation being released in a small space of time. I would imagine this would be accompanied by a lot of heat but there prtobably wouldn't be a major, long-term radiation threat apart from radioisotopes created by the gamma radiation bombardment.

Anyway, just another idea.

Chade:

Fill it with as much Smoke detector Actinium as you can get your tongs on, and duct tape it shut. Make a hole in the side and tape aluminum over the hole, so the alpha rays pass through the foil only.

This seems kinda pointless, alpha particles can be stopped by as little as a sheet of paper so surely actinium would block alpha particles as well. This means that if you had one block behind another it would only heat the forward block and virtually no alpha particles would get to your target. You could save yourself a lot of money and get just as good a yield.

Chade:

Now what is needed is a materal that will absorb beta radiation to give out alpha, or neutron radiation.

Helium . . .In a mass spectrometer an electron beam is used to knock electrons off the sample. Feed Helium into this, knock off the electrons and what you have is an alpha particle. A bit of a long way of going about getting a neutron but it should work.

[WTF]

streety, 174 is the mass number of an isotope of hafnium, the atomic number being 72.

I did some research on the x-ray bombardment of hafnium, and all I found was that when the APS X-ray beam was shone onto the sample of 31-yr. Hf-178, no detectable increase of the isomer decay occurred. (aps x-ray being Advanced Photon Source at Argonne national laboratory)

in english, if you bombard a pure sample of hf-178 with x-rays at 100000 times the strength of a dental x-ray, nothing happens.

source: http://www.eurekalert.org/pub_releases/2001-08/llnl-pcr081301.php

[nbk2000]

From what I've read about nuke designs is that, as long as you have a critical mass, you will ALWAYS get a self-sustaining chain-reaction resulting in an explosion. The term "fizzle" doesn't refer to a failure to explode, just the degree of power, the variance of "fizzle" being as low as 10 tons of TNT compared to the 10KT possible from a fully optimized design using the same amount of fissiles.

Also, Theodore Taylor of Los Alamos did a lot of work on the optimization of fission weapons, resulting in the construction of nukes small enough to fire from bazookas! :D He also did a lot of work on "improvising" nukes, using stuff like used reactor fuel (straight, no processing or isotopic seperation) to make and explode functional nukes.

He said the difference between a hiroshima nuke using 99% Pu239 and irradiated thorium with 10%Pu240 was the difference between a bomb core the size of a grapefruit, and one the size of a beach ball. When you're using a material heavier than lead, that's a lot of weight, which matters when nation-states are building missile warheads. But that wouldn't matter squat to someone making it to vaporize a city as a revenge weapon.

Oh, and Pu240 is a hard-gamma emitter, so it'd kill anyone not made of lead who got near it. But it'd still blow up a city.

"The Curve of Binding Energy" really is required reading for anyone interested in improvised nukes.

[Chade]

Wish I'd thought of that Streety. Yes, of course He nuclei as alpha can be made from irradiating Helium, which is ridiculously easy to acquire. A simple accelerator can then produce a stream of Alpha particles, and it all becomes an engineering problem not a million miles away from producing a dye laser. One source pumps the other, so an e-beam strikes a helium tube, the tube includes a strong electric field to accelerate the newly produced alpha particles away and you have a homemade beta source from the initial generator, an alpha source from the pumped tube, and if you use some aluminium foil as a target for the helium nuclei you could make a neutron source as well.
This is so tempting to try, but I'm going to fight the urge to experiment too much with radiation before it all goes Hahn-shaped. After all, it seems that this would be a method to easily (relatively) produce radioactive materials, but then, of course, they do tend to stay radioactive for quite a while. This seems like the sort of thing they could have done in one of those old scientific american 'amateur scientist' bits. I'd guess you'd need such high energy inputs that it would be very expensive, hence not commercially useful for plutonium production, but it would be possible to test the theory using some of the same stuff you'd use for home made lasers, and there's plenty of info on that on the net. I'm guessing that you'd encounter the same problems as with making lasers, along with the fact you now have radioactive gases sitting about.
This all now becomes a question of yield, and cost. If you can find a correct reaction chain (and I've still not identified the one David used) and materials, you could produce Plutonium isotpes just as he did. This is assuming such a chain exists. Most likely, it will require very large atoms to start with, and hence ones that are already radioactive, hence regulated. Mind you, besides the name, there's no reason to make plutonium. You'll scare the shit out of anyone who knows you're making it, but there's loads of other, better stuff to use for home made dirty bombs.

Plutonium is used in artificial pacemakers, as even in small (significantly sub-critical) masses will decay at such a rate they give out a lot of heat. This heat is used to power the pacemakers, as the alpha particles can't escape the case. From the fact that they're designed to sit in peoples chests for a number of years, we can surmise that none of the decay products are harmful either. So that particular isotope at least, is useless in a dirty bomb, and it's not cost effective for power generation if you use this method to get it. (No-one suggest extracting it out of people with heart trouble. That would just get messy)

By the way, to NBK2000, as far as being a hard Gamma emitter goes, I thought Gamma rays tended not to be as bad, as they went, by and large, right through you. They only get stopped by thick plates of lead, because it takes that much matter in the way before they ionise it. It's not stopped by paper as alpha is, because it goes right through the paper, without affecting it at all. In the same way, if someone standing in front of you doesn't block out a significant fraction of the rays, that also means they don't absorb a significant fraction of the rays, and you're ok. The worst radiation to get hit by would be neutrons, then beta, then gamma, then alpha.

The big problem with making weapons grade (over 92% Pu 239) Plutonium is that you can't have any contaminants in it if you want to make it go kaboom Nagasaki style, and contaminants include large quantities of Pu 240. There's no practical way to seperate these, as they have the same chemical properties, so what is typically done is to generate the Plutonium specifically for nuclear weapons by changing the fuel in a reactor before the 240 isotope forms. Essentially, 240 causes the same problems as any contaminant in an explosive. It can cause it to go off in your hand, or not at all. Except, in this case, it's slightly worse if it goes off in your hand. I'd be interested to see how Ted taylor dodged these problems.
For the record, they have even invented yet another buzz-word you may have heard (cause god knows we didn't have enough) which is 'weapons usable'. This has been used to refer to any grade of Plutonium. I know it's been used to describe stuff as low as 5% plutonium, but I'm sure they'd use it to describe a smoke alarm if it suited them.

As far as the Fizzle nukes go, you don't really need to bombard plutonium with neutrons to get it decaying. The reason the "Fat man" nagasaki bomb, which used Plutonium, was in several segments, blown towards the middle with explosives, was that it couldn't use the same method as the little boy Uranium Hiroshima bomb. That bomb had two hemispheres which were blown together, and reached critical mass. If you tried that with plutonium, the (just over) half critical mass would be deacying on its own at a much faster rate. By the time the bomb was set off (and Fat man was basically built then dropped on Nagasaki) you'd have a noticable drop in yield, if the weapon went off at all.

A Uranium nuke doesn't fizzle, as you're just slapping two subcritical masses together at 1000 ft/sec. They didn't even test the Hiroshima bomb. They did need to test the Nagasaki bomb, which used a shaped high explosive charge (don't know the details of it, sorry) to produce a perfectly spherical implosion shock wave. This blasted all segments into the core in microseconds. If the shockwave was at all asymmetrical, any segment could have connected first and resulted in and explosion that, although devestating, and certainly both a nuclear bomb, and a dirty bomb, would produce far less fall out, damage a smaller area, and, more importantly, not be predictable, compared to a full nuke. The device is far less useful if not even you know what it's going to do.

What you could do, is what the real guys researching this do, as a little snoop round wikipedia told me:
The cobalt bomb uses cobalt in the shell, and the fusion neutrons convert the cobalt into cobalt-60, a powerful long-term (5 years) emitter of gamma rays. In general this type of weapon is a salted bomb and variable fallout effects can be obtained by using different salting isotopes. Gold has been proposed for short-term fallout (days), tantalum and zinc for fallout of intermediate duration (months), and cobalt for long term contamination (years). The primary purpose of this weapon is to create extremely radioactive fallout making a large region uninhabitable. No cobalt or other salted bomb has been built or tested publicly.

This is a coating for nukes to make them useful as dirty bombs. Hands up if you believe the stuff about them never being built. Anyone?
This method gives the use of a dirty bomb, with the fun of a nuke. Any weapon that gives out EMP blasts, and starts full scale firestorms has got to be the one to go for.

Lastly, Streety, I think you're right about David being a bit free and easy with his Actinium. Maybe a thin parabolic shape of the actinium would have worked better. I think he was just using a sort of rough and ready method.

[streety]

WTF: Thanks for the correction, saying the 'atomic number' of hafnium was 174 was a foolish mistake. As you say, its the mass number.

It's also an interesting source as regards the Hafnium idea.

I was getting my info from articles such as:

http://www.newscientist.com/news/news.jsp?id=ns99993406
http://www.newscientist.com/news/news.jsp?id=ns99994049

These tout this technology as being almost established but it is certainly conceivable these articles were premature. On the other hand, perhaps the wrong wavelength of X-ray was used although I find it hard to believe they would make such a mistake. Anyway, as I said, it was only an idea. Even if it does work it probably wouldn't be feasible for the amateur to use.

nbk2000: I know I've heard it's possible to make a nuke the size of a cigarette but I didn't think anyone had gotten close to this. Do you have any details on how he managed to miniturise them?

Chade: Although this system would use very high voltages it shouldn't require all that much power. It would probably be very inefficient though.

[nbk2000]

Gamma is the most dangerous of the three (besides nuetrons) exactly because it can zip through your body. That means that, instead of simply zapping your skin or exterior musculature (like alpha/beta), it gets to zap every organ in your body, including your bone marrow/nervous system/brain/etc. Much worse.

And because it's so energetic, it strips off the electrons from the atoms of your cells, making a big pinball game of out of your body with all these energetic particles bouncing around inside you. :p

I have no idea how mr. taylor got the nukes so small. If I did, I could be working for N. Korea, now couldn't I? ;)

[streety]

I thought you might be holding out for an offer from somewhere that could feed, as well as pay you!;)

[Chade]

Biological effectiveness of radiation is given by a quality factor. This is a factor by which you multiply the radiation exposure to get the dose in units called 'Rems'. This gives the effect on a pure living sample, for example, a culture of cells in a petri dish, or if the radiation was directed at an open wound, to directly attack living tissue.
The quality factor for gamma radiation is 1, so the dose in rads is is the same as the dose in rems. For beta, the quality factor is 2, so the same dose in rads, is double the dose in rems compared to gamma or x-ray sources (see link). For neutron sources, the quality factor is 2-10 depending on energy, and for alpha it is 10.
So on exposed flesh, alpha is the worst, but as it's stopped by the layer of dead skin we have, it is harmless when it hits us. This is why you can hold a smoke alarm actinium source in your hand, but if you eat it, it is five times worse than eating a same strength beta source as i's now directly ionising living tissue. The dead layer of skin has no effect on beta, as you need a thin sheet of aluminium to stop an equivalent beta source. This means the dead skin layer (our own radiation shield) only stops alpha, which shifts it to the bottom of the table of biological effectiveness.

Gamma is less effective, because yes, one photon of gamma hitting a cell will do more damage, but the cross section of a photon is much smaller than a beta electron, so it's very unlikely to hit a cell. Any radioactive particle will only interact with, and therefore have any effect on, one particle. If a gamma particle passed through your body, it has had absolutely no effect on you. It only has any effect when it is absorbed, as it then ionises the atom it strikes. In DNA molecules, this often alters their structure and causes, in most cases, cell death, but sometimes causes a mutation, which can then give rise to cancerous growth.
Beta will penetrate your body to a sufficient depth to attack most of your internal organs (several cm, depending on strength) as a human is a fairly good shield. Not that I want to give anyone ideas. ;) This means that every particle has been stopped by them, and the particles have been stopped because they have crashed into your human shields constituent atoms, ionising them, so all the radiation has gone into them, leaving none to go into you. Of course, all these forms of radiation will ionise, as they're generally referred to, and defined by the name 'ionising radiation' to distinguish from em radiation, thermal radiation, etc.

The following link has the basics on calculating biological effectiveness, and there are loads more detailed links out there
http://www.camd.lsu.edu/msds/TrainingTest/radtesttrain/page12.html

[edit: sp, and slight clarification]

[pyromaniac_guy]

Originally posted by streety

nbk2000: I know I've heard it's possible to make a nuke the size of a cigarette but I didn't think anyone had gotten close to this. Do you have any details on how he managed to miniturise them?


the smallest critical mass of all the known elements is about 1 kg for californium 251... you could build a very small bomb with this material, maybe one that weighes 5 or 6 lbs, but certainly not cigarette sized...but it would cost a few trillion $ to get that much califonium!

Originally posted by Chade

A Uranium nuke doesn't fizzle, as you're just slapping two subcritical masses together at 1000 ft/sec. They didn't even test the Hiroshima bomb. They did need to test the Nagasaki bomb, which used a shaped high explosive charge (don't know the details of it, sorry) to produce a perfectly spherical implosion shock wave. This blasted all segments into the core in microseconds. If the shockwave was at all asymmetrical, any segment could have connected first and resulted in and explosion that, although devestating, and certainly both a nuclear bomb, and a dirty bomb, would produce far less fall out, damage a smaller area, and, more importantly, not be predictable, compared to a full nuke. The device is far less useful if not even you know what it's going to do.

.
first off, not all uranium based nukes are gun assembly devices. they can be used in an implosion device just like plutonium. Second, gun devices CAN fizzle. if the HEU is contaminated with too much U233, if the assembly time is too long (ie if there is a problem with the barrel that is used to bring the two pieces together), or if the weapon is subjected to a flux of either nuetrons or hard x rays from another nearly nuclear detonation.



Originally posted by nbk2000
From what I've read about nuke designs is that, as long as you have a critical mass, you will ALWAYS get a self-sustaining chain-reaction resulting in an explosion. The term "fizzle" doesn't refer to a failure to explode, just the degree of power, the variance of "fizzle" being as low as 10 tons of TNT compared to the 10KT possible from a fully optimized design using the same amount of fissiles.


nope... if you have just barely greater than unity, ie a slightly crittical mass, then the reaction rate will be so slow that it is entierly possible to not have any explosion. los alamos built fast research reactors out of HEU and plutonium back int he day, 'clementine' and 'godiva' respectivly. these reactors were essentially nothing more than a chunk of the apropriate nuclear material that either had another chuink of nuclear material brought near it to make it critical, or had a control rod withdrawn, to remove a nuetron absorber. interestingly enough the godiva reactor was damaged by an exceptionally large pulse of fission (obviously these reactors were critical for only very breif periods of time. operation for greater than a few seconds would casue the reactors to damage themselves), and was rebuilt with improved saftey devices as 'godiva II'


Originally posted by Chade

Personally, being a physicist, and not a chemist, I'd make my radioactive sources myself. Mr Cool is also dead right to say that linear particle accelerators are easy to make. if you are a physicist you got a whole lot wrong with your 'fast breeder reactor' story... first off all aluminum is piss poor at turning alphas into nuetrons. beryllium is best at doing this, but does so at the riddiculously low rate of something like 30 to 40 nuetrons per million alphas.. at that rate you might as well just use americiium as the radiological element to a dirty bomb.. same goes with particle accelerators. generating nuetrons with a small accelerator with a few MeV alpha just aint gunna do anything.... hell, the original work done with plutonium for the manhattan project used the berkley 60" cyclotron, a device that had a magnet the size of a school bus, and weighed a few hundred thousand pounds probably, and after something like 2 weeks of bombardment, they produced 2.77 micrograms of plutonium. that just ISNT a realistic route! if you really wanted to build a nuetron source, you would need a 30 MeV proton source and hit a high Z target... such spallation sources are the most efficent way to produce nuetrons, but 30 mev doesnt grow on trees... were tlaking an accelerator a good 10 or 20 meters long.


Originally posted by nbk2000

There's quite a few experimental reactors ran by industrial and university concerns that use sub-kilo amounts of weapons grade uranium and plutonium. With plutonium being on the same toxicity level as VX, with radiation hazard 1/1000th of that, it wouldn't take much effort to rob one of these places for their nuke material.


back in the early 90's the DOE instituted a program to get all of the high enriched uranium out of the hends of universities, ect, trading HEU fueld research reactor cores for LEU.... i have no idea how many, if any HEU research reactors are left out there, but I doubt the number of them is very large.... in all reality though, the level of enrichment wouldnt be anywhere nearly as important as the level of burn up in the used fuel... the more fission byproducts the better! (for the purposes of a dirty bomb)


ok... my own thoughts on the matter:

with all this talk of transmutation to make radioactive substances, or mining uranium, i see only 3 realistic aproaches:

1) steal a radiography source from an industrial or medical facility
2) buy depleated uranium counterweights from an aircraft salavge company. they ARE out there, and are fairly easy to get... I emailed several companies that advertised on barnstormers.com and actually found 1 company willing to sell me DU counterweights sevreal years back... only problem was thye wanted me to take ALL the coutnerweights from the airplane (they probably had to pay to get rid of them) and i didnt feel like having 600 lbs of DU in my garage.. I was hoping to just get 1 chunk for 'show and tell'
3) BUY a cobalt 60 radiography source... start a scientific welding buisness. call up the state and tel lthem you want to buy a cobalt 60 source for mobile radiography work. a permit is only a few thousand $ a year for even quite substantial amounts of Co 60... get your permit (nothing horribly special to do so, you dont even have to have a health physicist on staff in my home state) and then buy you some radioactive material. hell, you could even probably get away with buying more material than your permit allows by ordering from multiple vendors.

[Chade]

As far as the cigarette sized nukes went, I presumed that was a sub critical nuclear device that was referred to. For example, a smaller block of radioactive material that was heavily pumped with neutrons. Of course, it's theoretically possible to compess a material (for example in extremely high presure environments) to the electron degeneracy pressure without stopping its radioactive properties. So, although it doesn't help us much, you could have a smaller nuke in the heart of a white dwarf star.

first off, not all uranium based nukes are gun assembly devices. they can be used in an implosion device just like plutonium. Second, gun devices CAN fizzle. if the HEU is contaminated with too much U233, if the assembly time is too long (ie if there is a problem with the barrel that is used to bring the two pieces together), or if the weapon is subjected to a flux of either neutrons or hard x rays from another nearly nuclear detonation.
yep, thanks for the correction.

or had a control rod withdrawn, to remove a nuetron absorber.
Hmmm, has anyone every tried that mechanism for a nuke? It'd seem easy, but maybe with reduced storage time as the control rods got saturated.

if you are a physicist you got a whole lot wrong with your 'fast breeder reactor' story... There might be a lot wrong with it regardless. I was re-telling the 'fast breeder story'. It's not something I did myself. And like I said, I'd not identified the reaction chain David used.
As far as my idea went, it was just an idea, and one I suspected would not be feasible. Still, now I know the yields will be so low, it may be safe enough to try some small scale experiments.

As far as universities not having any U or Pu, I do know that my uni had a neutron source of some type, shielded in what looked like a box about the size of a washing machine. As far as I know, they still have it. I remember when we were all shown round the labs the demonstrator said 'Yes, and we even have our own neutron source. Yes, that thing you're sitting on...' To which one of the students hopped off it rather quickly.

[pyromaniac_guy]

Originally posted by Chade
(1)As far as the cigarette sized nukes went, I presumed that was a sub critical nuclear device that was referred to. For example, a smaller block of radioactive material that was heavily pumped with neutrons. Of course, it's theoretically possible to compess a material (for example in extremely high presure environments) to the electron degeneracy pressure without stopping its radioactive properties. So, although it doesn't help us much, you could have a smaller nuke in the heart of a white dwarf star.


(2)Hmmm, has anyone every tried that mechanism for a nuke? It'd seem easy, but maybe with reduced storage time as the control rods got saturated.

(3) There might be a lot wrong with it regardless. I was re-telling the 'fast breeder story'. It's not something I did myself. And like I said, I'd not identified the reaction chain David used.
As far as my idea went, it was just an idea, and one I suspected would not be feasible. Still, now I know the yields will be so low, it may be safe enough to try some small scale experiments.

(4)As far as universities not having any U or Pu, I do know that my uni had a neutron source of some type, shielded in what looked like a box about the size of a washing machine. As far as I know, they still have it. I remember when we were all shown round the labs the demonstrator said 'Yes, and we even have our own neutron source. Yes, that thing you're sitting on...' To which one of the students hopped off it rather quickly.

1- a sub critical nuke is NOT a nuke. there would be no nuclear yeild from a nuke the size of a cigarette, no matter what material you used as the special nuclear material. such a device would simply be a dirty bomb

2- why would you want to use such a device for a nuclear explosive? even if you removed the control rod with sufficent speed, you would have a big gaping hole in the fissile material from where the rod was removed from, this would lower the effective density of the material, and increase the critical mass (or decrease the fission efficency with the same amount of material at normal density)

3- the story you were tlaking about was from harpers weekly, or readers digest. it may be urban legend, or it may be factual, but such a device was NOT a breeder reactor. there was no chain reaction because there was no criticality. there was (or they would serve no purpose) control rods, because there was no criticality.

4- oh there is plenty of radioactive material floating around at universities, but what NBK was talking about was highly enriched uranium used inr research reactors... There isnt a whole heck of alot of this floating around anymore. University of florida in gainsville changed out their reactor fuel to 20% back in '90 iirc previously they had been running with about 4.5 kg of HEU. this is enough enriched uranium that it would be plausible to build a sophisticated nuclear bomb with. the risk of theft is why most universities dont have that stuff around any more..

[Chade]

Ok, rather than resort to 'yes it is, no it isn't', I'll include references to back up my points.

(1) A nuke refers to a nuclear weapon [1, 2] so I take that to mean any weapon that gets its force from nuclear energy, be it fission or fusion. I'm proposing a 'special material' such as HEU, or Plutonium. Hardly that special. And then taking a sub critical mass that won't explode on its own, as it does not produce enough neutrons to generate a self sustaining reaction [3].

The nuclear material will give out energy from the fission that naturally occurs in any radioactive material, but the energy produced will not be enough to cause an 'explosion'. In other words, it won't be enough to blast the material apart [4]. You then supply the neutrons, by whatever method, be it a neutron gun, a beam of high energy neutrons sent from a significant distance, or, in a conventional critical mass nuclear weapon, just more of the same substance. The neutrons cause extra fission, and more energy released. With a large mass (just sub critical) of radioactive material, and a strong source of neutrons, it is possible to incerase the decay rate, and hence the power output. If this can then generate enough energy to explode, I'd call that a small nuke.
If you could get in enough neutrons to stimulate fission of the same proportion as a critcal mass, you'd get a nuclear device of power proportional to its weight. For example, if we say the critical mass for HEU was 15Kg [5], then 7.5KG, if it could be stimulated with neutrons so the same proportion of atoms split as in 7.5Kg of a 15Kg device going critical, you would have a nuclear device with half the power of a full 15Kg device. I've heard nothing about cigarette sized nukes, and that would seem to be pushing it a bit to say the least. You'd need one hell of a neutron input to make that go off. Even a 7.5Kg device as described would probably need more than half the neutron output of a full 15Kg nuclear explosion. And that's a lot of neutrons.

My (admittadly playful) idea was that you could use a strong focused ray of neutrons, for example from a satellite (totally sci-fi here) to strike a sub critical nuclear device (nuke). Trouble is, you'd be far better off swinging your neutron source all over downtown to cause your death and destruction then. I can't see how it could be possible, thinking about it.

(2) Why? Because it's there.
How many inventions and innovations have come from trying to look at things a different way? Maybe it's be less efficient, but maybe it could have a use or application elsewhere.
And maybe it doesn't have to be inside. Perhaps a case of Cobalt arount it, or a bath of heavy water?

(3) Dear, dear, dear. The story was from none of those places, and I said where I heard it. From three Phd students in various fields of physics phenomonology, and from a half hour documentary on David Hahn [6]. I have to say, when they interviewed him, he didn't look like an urban legend. And when they showed the modelled version of his BREEDER reactor, it had cobalt fuel rods. (obviously the real one is still under the nevada desert.) The cobalt rods, I'm presuming, were there for safety, to ensure the reaction did not produce more plutonium than he could safely handle, but yes, the reaction chain produced plutonium, however little. If it 'breeds' radioactive fuel, then it is, by definintion, a breeder reactor [7].
And you do not need anything to be critical for control rods to be useful. They absorbed neutrons, making his reactor safer, controlling it.
You said 'there was no chain reaction, because there was no criticality.' This prompted me to look back over my posts, to see if I'd said something blatently wrong, or made a typo. No, I didn't say there was any criticality (criticality of what, anyway? Do you mean going from a breeder to a fast breeder reactor? That would produce more fuel than was used, and control rods would become essential.) And nor did I say there was a chain reaction, which has an associated meaning already in nuclear physics. I said there was a reaction chain, meaning that from the initial materials fission products are formed, maybe irradiate again, maybe decay again, or whatever. All I was referring to was the chain of nuclear reactions that takes you from your initial radioactive materials to Plutonium. As I said, I don't know how that happened, and it'd take a while to research it.

(4) I knew what he meant. I was just using it as an excuse to tell that anecdote.
Ok, maybe that one wasn't worth it.

And for all the nitpicking, you missed my real mistake. I called Davids device a 'Fast Breeder' reactor, when it was simply a breeder reactor. As far as I know, anyway.

[1] Dictionary.com
[2] The Chambers dictionary
[3] http://howthingswork.virginia.edu/nuclear_weapons.html
[4] http://www.tpub.com/doenuclearphys/nuclearphysics29.htm - plus some basic maths
[5] http://www.oxfordresearchgroup.org.uk/publications/books/handbook/ch3.pdf
[6] OK, I have this on tape. If anyone wants a copy in the UK (PAL format) I can copy it for you.
[7] http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/fasbre.html#c1

[pyromaniac_guy]

Originally posted by Chade

The nuclear material will give out energy from the fission that naturally occurs in any radioactive material, but the energy produced will not be enough to cause an 'explosion'. In other words, it won't be enough to blast the material apart [4]. You then supply the neutrons, by whatever method, be it a neutron gun, a beam of high energy neutrons sent from a significant distance, or, in a conventional critical mass nuclear weapon, just more of the same substance. The neutrons cause extra fission, and more energy released. With a large mass (just sub critical) of radioactive material, and a strong source of neutrons, it is possible to incerase the decay rate, and hence the power output. If this can then generate enough energy to explode, I'd call that a small nuke.
If you could get in enough neutrons to stimulate fission of the same proportion as a critcal mass, you'd get a nuclear device of power proportional to its weight. For example, if we say the critical mass for HEU was 15Kg [5], then 7.5KG, if it could be stimulated with neutrons so the same proportion of atoms split as in 7.5Kg of a 15Kg device going critical, you would have a nuclear device with half the power of a full 15Kg device. I've heard nothing about cigarette sized nukes, and that would seem to be pushing it a bit to say the least. You'd need one hell of a neutron input to make that go off. Even a 7.5Kg device as described would probably need more than half the neutron output of a full 15Kg nuclear explosion. And that's a lot of neutrons.


your lack of comprehension in matters you talk of is amazing, go back to washing bottles instead of trying to make people think you know what you are talking about.

ready for a schooling?

a 'critical mass' is a chunk of fissile material large enough so that the rate of nuetron loss to the outside world is less than the number of nuetrons that go on to stimulate other nucleons to undergo fission. if you have a critical mass of material and inject 1 single nuetron, the level of nuetrons running around inside said mass will begin to rise exponentially. the more critical a mass is, the faster the rise in number of nuetrons. thats the whole reason why a nuclear bomb explodes. a self suporting chain reactions liberated more and more energy untill the device physicaly destroys it's self, resulting in a pretty mushroom shaped cloud... NOW, if you take a chunk of fissile material of less than the crittical mass, you will NEVER get the material to generate more nuetrons than it looses to the environment. you would always have to pump more nuetrons in. thats why you cant just take a big 'nuetron gun' and aim it at an arbitrarily small chunk of fissile material and expect a small nuclear explosion. the number of nuetrons required to get a small chunk of fissile material to explode with ANY yeild is absolutly staggering. infact, there are no methods for generating such a burst of nuetrons, other than the possible exception of a nuclear bomb... do the math yourself instead of spouting off crap.. look at the bomb that exploded over hiroshima... 60 kg of uranium was in the bomb to make up the supercritical mass... about 700 grams, or lets say 3 moles of uranium fisioned. if you only had a sub critical chunk of uranium sized so that only 50% of the fission nuetrons triggered other fissions (ie the rest were lost to the environment) you would need to generate about 1.6 moles of nuetrons in the timespan of 1 fission generation to get that small chunk of uranium to explode with the same yeild as the little boy bomb. if you had a alpha source / beryllium nuetron generator, assuming 30 muetrons per million alphas, you would need an alpha source capible of producing about 3 x 10^28 alphas per 10 nanoseconds or acout 1.8 x 10^38 DPM of specific activity... lets just round that to about 10^28 curies.... oh, and keep in mind that such a large source of alphas would be putting out about 7.5 kilotonns worth of energy every 10 nanoseconds. only want a 'mininuke' to have 1 millionth the explosive force of hiroshima? a measly 15 kg of tnt nuclear yeild? wel lthen you would only need a 10^22 curie alpha source. unfortunatly it would still be putting out 7.5 kt of energy every 10 miliseconds...

do you see now how futile it is to build a 'mini nuke' with a subcritical mass of fissile material and a nuetron source? you get more energy liberated in a wet fart than you would from any practical device that relied upon such a process.




Originally posted by Chade

(2) Why? Because it's there.
How many inventions and innovations have come from trying to look at things a different way? Maybe it's be less efficient, but maybe it could have a use or application elsewhere.
And maybe it doesn't have to be inside. Perhaps a case of Cobalt arount it, or a bath of heavy water?


do you even understand what critical mass means? cobalt AROUND the mass? a crittical mass is one where more nuetrons are used internally to further a fission chane than that witch are lost outside the chunk of material. once it leaves the chunk of uranium/plutonium, it doesnt matter if you have a sleve of cobalt around it or cover it in silly putty. Hell, cobalt has a non zero scattering cross section, some there would be some amount of reflection going on and subsequent REDUCTION of the crittical mass... try to do what you propose and you will be one of those guys who die after seeing a blue flash of light :)



Originally posted by Chade
(1) A nuke refers to a nuclear weapon [1, 2] so I take that to mean any weapon that gets its force from nuclear energy,

by that deffinition, a smoke detector is a nuclear weapon, because it liberates 'nuclear energy'. as a rule of thumb a device isnt considered a nuclear weapon unless it produces a nuclear yeild of greater than the equiovalent of 20 lbs of tnt, at least fromt he standpoint of international treaties :)

Originally posted by Chade

(3) Dear, dear, dear. The story was from none of those places, and I said where I heard it. From three Phd students in various fields of physics phenomonology, and from a half hour documentary on David Hahn [6]. I have to say, when they interviewed him, he didn't look like an urban legend. And when they showed the modelled version of his BREEDER reactor, it had cobalt fuel rods. (obviously the real one is still under the nevada desert.) The cobalt rods, I'm presuming, were there for safety, to ensure the reaction did not produce more plutonium than he could safely handle, but yes, the reaction chain produced plutonium, however little. If it 'breeds' radioactive fuel, then it is, by definintion, a breeder reactor [7].
And you do not need anything to be critical for control rods to be useful. They absorbed neutrons, making his reactor safer, controlling it.
You said 'there was no chain reaction, because there was no criticality.' This prompted me to look back over my posts, to see if I'd said something blatently wrong, or made a typo. No, I didn't say there was any criticality (criticality of what, anyway? Do you mean going from a breeder to a fast breeder reactor? That would produce more fuel than was used, and control rods would become essential.) And nor did I say there was a chain reaction, which has an associated meaning already in nuclear physics. I said there was a reaction chain, meaning that from the initial materials fission products are formed, maybe irradiate again, maybe decay again, or whatever. All I was referring to was the chain of nuclear reactions that takes you from your initial radioactive materials to Plutonium. As I said, I don't know how that happened, and it'd take a while to research it.


great.. you hurd it from phd students.. i have also heard the rocket powered thunderbird crashing into the side of a mountain story from phd students.... that doesnt make the story any more true...

another school lesson.

control rods, ie cobalt or a similar materal with a large nuetron absorption cross section are used to control the criticality of a nuclear reactor. This kid couldnt possibly have put together enough thorium to have a critcal mass, so any control rods would serve no purpose. furthermore, a reactor is a device that can maintain a self sufficent chain reaction, if criticality is not reached, then you dont have a reactor. what this kid built (if it's not urban legend) is not a breeder reactor, fast or otherwise... it's a nuetron source that happens to be sitting next tome fertile material (thorium)

[Chade]

OK, ok, calm down.

NOW, if you take a chunk of fissile material of less than the crittical mass, you will NEVER get the material to generate more neutrons than it loses to the environment. you would always have to pump more neutrons in. thats why you cant ...
Yes, absolutely. Given. I was talking about pumping in the full quantity of neutrons to cause the excess fission. In essence, throwing in VAST amounts of neutrons. And I said it was unfeasible. In fact, my words were:
I can't see how it could be possible, thinking about it.
We, as far as I can tell, agree on this. Sub critical nukes seem (never say never) to be impossible.

(2) OK, that last sentence was an afterthought, without the thought. I freely admit that surrounding a critical mass will do no good whatsoever to stop an explosion. I take it back and beg forgiveness for a dumbass, ill concieved plan.
(but it wasn't as it I was going to rush out and build one in my shed or anything)

A nuke refers to a nuclear weapon [1, 2] so I take that to mean any weapon that gets its force from nuclear energy,
Well, I wouldn't call a smoke alarm a weapon, so I think I'm OK on that score. And now that we've established that, barring a miracle, we can't have sub critical nukes, the whole thing becomes moot. Besides, the press use words however it suits them anyway, and everybody follows.
As far a miracles go, it'd be one I'd like to see though. Imagine Jesus (or insert your favourite deity here) returns in all his glory, and decides it'd be kinda fun to wreak vengence on evildoers by lobbing subcritical nukes about the place. There's a religion I could get behind. (I'm so going to hell now!)

great.. you hurd it from phd students..
And saw a half hour tv show, where they interviewed him. They interviewed people from his neighbourhood. They even tracked down the lady in the antiques shop where he bought one of his radium clocks. Seriously, if anyone in the UK wants a copy of this tape, I will sent it to you for free. If someone has a TV tuner card and can record it to upload onto the FTP, so much the better. I've set up a hotmail account especially. send an address, a PO box, or some location to chadefarseer@hotmail.com.

control rods, ie cobalt or a similar materal with a large nuetron absorption cross section are used to control the criticality of a nuclear reactor. This kid couldnt possibly have put together enough thorium to have a critcal mass, so any control rods would serve no purpose. furthermore, a reactor is a device that can maintain a self sufficent chain reaction, if criticality is not reached, then you dont have a reactor. what this kid built (if it's not urban legend) is not a breeder reactor, fast or otherwise... it's a nuetron source that happens to be sitting next tome fertile material (thorium)
OK, the definition as far as I know is that a reactor is one where the nuclear reaction is created and maintained. It's really stretching the limits as to whether you call it a reactor or not. I would, as it's making plutonium and on the short timescale, seemed (and I could be wrong) to be maintained by the excess radioactive material. On the other hand, there's a whole bunch of reasons why you wouldn't call it a reactor. I think this one's 50/50.
He did have control rods in his device though. Cobalt absorbs neutrons. I don't know exactly why he added them. Perhaps they were elevated above the core in case he got too much neutron producion, and needed a safe way to reduce it. Maybe he was just following instructions and had ended up with a far less efficient device without realising it. Or maybe there was another reason.

your lack of comprehension in matters you talk of is amazing, go back to washing bottles instead of trying to make people think you know what you are talking about.
Can we end the flame war, and discuss how this affects the potential manufacture of dirty bombs now? Please?

Without knowing the intricacies of what was done in that experiment, I don't know if the end result would have been any more effective as a dirty bomb than if he'd just blown the original radioactive components across town with conventional explosives. And I now can't see any feasible way of generating usable amounts of radioactive material yourself. All the methods left seem reduced to the (to my mind) rather dull methods, of needing radioactive materials to begin with.
I've ordered the book NBK2000 recommended. but it'll be a couple of weeks wait. Maybe it'll allow me to get a bit more info on these interesting sounding experiments.
I still think radioactive sources are ideal for dirty bombs as opposed to other substances (chemical or bacterial) as they stand up to much more extreme conditions, and hence, stronger explosives to disperse them further. Next most stable, and so dispersed next furthest, would be atomic contaminants, then more stable molecular chemical contaminants.

On a side note, does anyone know whether prions would be effective biological agents if airborne? I'm thinking something like vCJD prions, as they are apparantly simpler even than virii. Perhaps they could be dispersed, with some protection from the most extreme conditions, by an explosive device? Very different type of dirty bomb indeed. I'm just thinking that if they are simpler than bacteria and virii, they might be more resiliant, and probably harder to detect.

[nbk2000]

Hi Ho, the Nuke is dead!

Follow the Yellow Brick URL (http://www.roguesci.org/theforum/showthread.php?threadid=1638), sayeth the Wizard, NBK. ;)

[pyromaniac_guy]

Originally posted by Chade

Without knowing the intricacies of what was done in that experiment, I don't know if the end result would have been any more effective as a dirty bomb than if he'd just blown the original radioactive components across town with conventional explosives. And I now can't see any feasible way of generating usable amounts of radioactive material yourself. All the methods left seem reduced to the (to my mind) rather dull methods, of needing radioactive materials to begin with.


i agree... transmutation on the home / terrorist scale would be unfeasible. you would be much better of just buying or stealing radioactive materials.


Originally posted by Chade


On a side note, does anyone know whether prions would be effective biological agents if airborne? I'm thinking something like vCJD prions, as they are apparantly simpler even than virii. Perhaps they could be dispersed, with some protection from the most extreme conditions, by an explosive device? Very different type of dirty bomb indeed. I'm just thinking that if they are simpler than bacteria and virii, they might be more resiliant, and probably harder to detect.

this is actually a fairly interesteing idea, however i doubt prions would be suitable for delivery by an explosive mechanism. 140F or so is al lthats required to denature the prion that causes creutzfeldt jakob... BUT lets say you were able to get your hands on a vat of these prions (maybe after you steal the brain of a BSE aflicted cow) and you worked at the local all you can eat buffet... every day you spray the prions onto a cold portion of the meal, say the lettuce used for salads. since it may take decades for symptoms to apear after being exposed to such prions, can you imagine the shitstorm that would ensue when a whole town eventually develops vCJD?

[Chade]

Ah, finally figured it out. I did say I'd look into it when I had a chance. Very irritating that that TV show, as you would guess, missed out certain key points of Hahns reactor (if you call it that) that would make it impossible for anyone to copy without knowing what was omitted and why. Basically stopping someone parroting his experiment and killing themselves.
The big key factor was that his reactor core of Americium (241) and Radium (226) was intimately mixed with aluminium to make a core which emitted lots of neutrons. Basically it was as much alpha emitting material as possible mixed with material to absorb the alpha and emit neutrons. He actually used aluminium and beryillium, as beryillium is better at this process. Don't ask me why he didn't just use beryillium. I guess he couldn't get enough.
The neutrons then hit the thorium (232) and convert it to plutonium. That's all it was. When I find out more details about this, it just seems quite disappointing. For example, although he had extracted radium from a variety of old clock hands, the bulk of his radium came from the clock he detected driving past with his geiger counter. Whoever had painted up the clock had left a full vial of radium in the back of it.

What I had thought was happening was that materials were decaying into other forms, then bombarded with more radiation and decayed into other products. I thought this was why he had such a weird collection of elements all chucked in together. Turns out he was just dumping all his radioactive materials together to get the greastest effect.

Also, as to the cobalt control rods, the program didn't really give the whole story here. The reactor, as it was just before David dismantled it, did have two cobalt drill bits. David had put these in just after the radioactivity shot off the chart, as a last ditch attempt to control the radioactivity. It didn't work, obviously, as he'd have been better served surrounding the core more effectively with cobalt, or another moderator, or just taking the core out.

Incidentally, I hear that one key factor in Davids other experiments that hindered his progress is that he was unable to slow down his neutrons, which were travelling too fast for some interactions. http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/moder.html#c3
has some info on how you could moderate a reaction. Seems carbon is a good moderator, which is, I suppose, why he used it with the Thorium. I think if he'd just designed his reactor so he could flood the core with water, he'd be a lot better off. If I was trying it, I'd also work on casting a shell out of cobalt that could fit around the core in case of emergencies.

Seems to me, having looked into it a bit more, that the physics behind it was sound, as far as making plutonium (in very small quantities) went. I'm nowwondering if you could get an appreciable amount of plutonium to use as a toxin, or in a small dirty bomb. Perhaps making enough colloidal plutonium oxide to drop into an air conditioning system. Davids own claim was "I believe I did produce a few atoms of, of plutonium. Maybe a couple fissions here and there, but I don't think anything sustained any kind of reaction. You see, I believe it was the thought that counted."
Obviously there are no real figures for how much you'd produce in a home reaction, but you don't need a vast amount of plutonium to be toxic. I've heard microgram amounts will kill if inhaled or ingested in a fine enough powder, but I've not seen the studies this came from, or whether it's just one of those things that's been said so often it's become fact, like the old chestnut of men thinking of sex every seven seconds. (Now that's an urban legend)

Still think it's unlikely, but there is a little voice piping up in the back of my head. The old saying 'It's remarkable what people can accomplish when they don't know what they're trying to do is impossible.' You'd need an almighty effort to get to the stage David Hahn reached, having the greatest trouble getting even small amounts of radioactive materials, which are, by and large, tightly controlled. If you wish to try out some experiments in radioactivity, the following may be of use...

The (very limited) OTC radioactive survey:
Americium (241) Extracted from smoke detectors, £4 detector has 1/5000 g
Radium (226 + others) Extracted from radium paint, radium chloride, or pitchblende (1g in 10 Tonnes)
Thorium (232) Thorium lantern mantles - Still available on ebay, possibly in some stores
Tritium - Found in Night sights. David extracted it, took the sight to be repaired, took the tritium agian and went to a different shop to have it repaired. Repeat.
Uranium (Ore) Pitchblende. Still found naturally in some places, if you have a sensitive geiger counter, a knowledge of geography of the area, and don't mind getting it piecemeal, you can go gathering.
David managed to get all of these materials, but you'd need to get lucky or rich to get significant amounts.

If you're doing your own investigations, there's shedloads you can experiment with, even if you're keeping it to a safe level. If you do start using your neutrons to irradiate things, and you end up with hahns problem of materials getting too radioactive, consider dumping certain items as near as poss to you nearest nuclear facility. If you're dumping stuff that can't be traced to you, it's best to do it somewhere it'll be detected and properly disposed of, and where there's a chance it'll be put down to their leaks. Somewhere that's fenced off, but not monitored, like a perimeter fence where the tighter security is further inside would be good. Or by a railway line or road into an installation for carrying nuclear materials

I'd start with simple experiments with shielding for radioactive materials. Then making neutrons from alpha sources, and progress from there.
Points for further study would be: possible yields of plutonium from a hahn style reactor, efficacy of various moderators, and neutron absorbers, Manufacturing beta and gamma sources from neutrons, decays of various materials when neutron irradiated, then irradiating the products to find more interesting chains of radioisotopes.

Personally, I think you could get enough Plutonium to kill someone if you had a full Hahn reactor running, but that's a completely blind guess.

[mrcfitzgerald]

Nice post, Chade - just one thought...
The neutrons then hit the thorium (232) and convert it to plutonium

Actually, the neutrons convert Thorium-232 into Uranium-233 (which interestingly enough, is a fissle matter w/ a critical mass of only 12Kg). But this alone does not explain the high radioactivity level found at his home, I am willing to bet the side reaction with the Thorium-231 impurities allowed significant formation of Uranium-232. Uranium-232 being significant as its decay chain includes many potent gamma emmiters (and exhibits 720 spontaneous fissions per second per kilo) ; the extent of U-232 formation worsens with unmoderated neutrons, as they directly transmute Th-232->U-232. According to Cary Sublette of the NuclearFAQ fame,

The short half-life of U-232 also gives it very high alpha activity. Denatured U-233 containing 1% U-232 content has three times the alpha activity of weapon-grade plutonium, and a correspondingly higher radiotoxicity

Assuming he had about 4Kg of thorium or so, with .5% th-231 - that corresponds to about 7Kg of weapon grade Pu (assuming he had converted all of the Th-231, which he most certainly did not).
However even a few ounces of U-232 would still constitute a major radioactive hazard - certainly worthy of the clean up effort...

[matjaz]

Originally posted by Mr Cool
"Is it possible to speed up Uranium's decomposition to Radon?" ...
No. Although it'd be fun if you could speed up radioactive decay. ...
But sadly it's not possible yet, and probably never will be.
Not that it could be employed here, but just as a curiosity: At least the decay constant of any nuclei decaying via electron capture can be "squeezed" up a bit. The trick is to force the K electrons to close in on the nucleus thus increasing the probability of en electron "entering" the nucleus at the moment the guy wants to go beta+.

Of course you need to maintain tremendous pressures for a period of time to see some extra decays. The little Pauli inside the atom doesn't like it at all... :) But, it can be done so as to make a measurable difference. They use high-powered pulsed lasers to heat/compress the matter. I hear that the fractional change in decay constant is on the order of 10^-8 per bar.

[gkarmis]

There is an analysis of what a dirty bob could do
http://www.fas.org/faspir/2002/v55n2/dirtybomb.htm

[daysleeper]

If the intent is to just spread mass panic, with a detectable amount of radiation, then thorium is the best material I think.
It is highly available, I also know for a fact that even in the small amounts used it will set off geiger counters, part of my training at work.

The tungsten tip used for TIG welding is the most obvious source, and no suspicion is arroused when bought.
You simply buy the 2% thorinated Tungsten electrode . It is designated as electrode EWth-2, it has a red markings on one end for easy identification. Thorium oxide is added to the tungsten of certain TIG electrodes to aid in the emission of electrons from the elctrode to the base metal.

A good source is EBAY, or Tigdepot.com

Also, since tungsten is very brittle, smashing it into power is easy, to easy in fact, I hate dropping my TIG torch and having it land on the tip, pain in the ass having to take it out and re-shape it with my grinder and all.