Nuclear Fuel How-To

ATMosby writes "The BBC has an article that pretty much sums up everything you might need to know if you wanted to refine nuclear fuel and build some atomic weapons." From the article: "Uranium is the basic raw material of both civilian and military nuclear programmes. It is extracted from either open-cast pits or by underground mining. Although uranium occurs naturally all over the world, only a small fraction is found in concentrated ores. When certain atoms of uranium are split in a chain reaction, energy is released. This process is called nuclear fission."

Comments

Fission? No kidding!

[sjbe]

When certain atoms of uranium are split in a chain reaction, energy is released. This process is called nuclear fission.

Thanks for clearing that up for us...

So?

[0racle]

Big deal, my high school physics textbook had all this information as well.

I wonder how many people are going to think this is some sort of threat to 'national security.'

Re:So?

[AKAImBatman]

Big deal, my high school physics textbook had all this information as well.

Actually, your high school physics book probably has *more* information. This "in-depth article" is nothing more than a few graphs and a description.

That being said, nuclear fission technology is stupidly simple in it theoretical foundations. Once one is able to build an atomic pile (demonstrating sufficient purity of U235), it's only a short period of time until a gun-type A-Bomb can be made. All you need is two sub-critical masses of U235 that add up to a critical mass. Mount one mass in a stationary (and strong!) holder. Take the other piece and mount in some sort of gun. The more force the gun can impart on the second piece, the better. Fire the first piece at the second, and viola! You're dead!

Ermm... I mean... you can see a pretty light show from the U235 compressing into a super-critical bundle.

Nuclear reactors and Implosion bombs are a bit more difficult, but not beyond any country with sufficient industrial capability. This article from the magazine "The Progressive" tells you how to build a hydrogen bomb. Good luck on that, though. Implosion bombs aren't too bad with computer modelling, but H-Bombs are REALLY, REALLY tricky.

Of course, if a Slashdotter with no formal training in nuclear science can desribe how bombs are built, is there any question as to why nuclear materials are carefully controlled?

Re:So?

[Rei]

I'm wondering why slashdot seems so impressed by this; this is all common knowlege (and very incomplete for the public domain). I mean, using language "This is then purified in a chemical process and reconstituted in a solid form known as "yellow cake" "? "A chemical process"? Can they get more vague? Why not just state some of the processes, like dissolution of the ore in strong acids (phosphoric, sulphuric, or nitric)? Heck, I once ran into a paper that discussed proper methods for manufacture of appropriate corrosion-resistant seals for gas centrifuges. :P

Here we go again: "converted into a gas, uranium hexafluoride". Why not just say how hex is produced - it is dissolved in nitric acid to produce uranyl nitrate, reacted with ammonia to produce ammonium diuranate, reduced with hydrogen to produce UO2, then converted with HF to UF4 (which is a nice storage method, because it can be readily converted to either hex, ceramics, or metal). You react the UF4 with fluorine to produce UF6.

Just stating the chemical pathway isn't giving away any sort of secrets; this is all public domain. The technical challenges are in setting up a large scale refining process, and not getting caught doing it, because large quantities of many involved chemicals (for example hydrofluoric acid) are monitored.

They only mention two enrichment methods (gas diffision and gas centrifuge), and ignore some of the newer methods in development (I'm rather fond of the LIS (Laser Isotope Separation) methods; they take advantage of the fact that the different isotopes of uranium ionize differently from different wavelengths of light. AVLIS works on uranium gas ionization, while MLIS works by encouraging the selective disassociation of U235 hex. There's a couple other methods in development as well.

Even what they mention of gas diffusion and gas centrifuges is vague. For example, the whole world was reading two years ago about the controversy over the "aluminum tubes" - the centrifuge rotors are flow-formed from tubes and welded to a central shaft, which spins on a fine bearing at the base and is magneticly suspended at the top. Because of the high forces on the rotors, you need high grade alloys. Iraq never had used aluminum - its imported designs called for maraging steel, and the aluminum was ill-suited for welding as well. This was all over the news - where were the editors then?

I could easily keep on going, but I think the point is made - why are the editors impressed by this article? It's nothing - they've clearly never bothered googling for uranium enrichment before.

Re:So?

[AKAImBatman]

My favorite method is the Buckets method of separating the UHF in your backyard. Quick (yeah, right), easy (if you are REALLY strong), and safe (you'll be dead when you're done)! What could be better? ;-)

Re:So?

[Rei]

The tough thing about implosion bombs is getting a uniform shockwave. This requires high purity explosives that behave exactly the way you want, every time, high-predictability capacitors, and very time-precise triggering mechanisms. Parts that can be used in the triggering mechanisms (such as krytrons) are harder to come by.

Such capacitors and explosives are within the reach of a state like Iran (and Iraq claimed to have produced them before the first Gulf War), Krytrons, however, use beta from Ni-63 to help keep the gas in them ionized (to allow for a faster arc discharge), so they take more effort.

Re:So?

[Doc Ruby]

Iraq got nuclear training from Pakistan's AQ Khan during the 1980s, while the US beefed up Hussein's rudimentary WMD program. And Pakistan got its krytrons from the US at that time, too.

Re:So?

[Rei]

That's not the case with a gun-type weapon. Colliding two pieces of >90% enriched U-235, (with alternating spheres of polonium and berylium the center of the device to be crushed by the high explosives), at high speeds, will give you a nuclear explosion (even if low yield), even if you don't know why.

Amateurs who don't know much at all about particle physics build Farnsworth Fusors for fun. All you need to know to build something is a design. Physics doesn't care if you know why it works.

Re:So?

[Rei]

So your issue is really just how detailed are available designs, then? Ok, lets use a public description of Little Boy (the first one I ran into - much better designs are available):

64,1kg of HEU (80% average enrichment). The bullet was a cyllindrical stack of U-235 rings each 10cm wide and 16 cm long, containing 25.6kg total (6 rings). The stack was backed by a tungsten carbide disk and steel backplate, all within a 1/16th inch thick steel can to form a complete projectile. The target was a hollow cylinder 16 cm long and wide, weighing 38.4 kg. It was fabricated of two rings that were inserted into the bomb separately. The bullet contained 89% enriched HEU; the target the rest of the uranium.

The bullet was encased in a boron "safety sabot" to help prevent accidents; there was also a plug on the target. When fired, these would strip off. You could easily omit such safety features if you were unconcerned with safety.

The tamper assembly was thick tungsten carbide surrounded by a steel forging, 60cm wide, with a combined mass of 2300kg. A hole was bored in the forging to insert the tamper and the target; the hole was threaded to allow secure attachment of the gun. At the back of the hole, past the target, there was space for one or more polonium initiators (I can dig up several polonium initiator designs for you if you would like; Little Boy used four very inefficient ones - the bomb would have worked without an initiator, and the decision to use an initiator wasn't even established till March 1945).

The gun was a 3" antiaircraft gun, 6.5" wide, 6 feet long, bored out to 4", weighing 450kg, with a breech block of 34kg. Standard cordite propellant was used, to achieve a 300m/s (slow) velocity. Of course, given how unsafe the Little Boy design was, even dropping the device hard enough could have given some significant (even full) yield.

The complete weapon was 126 inches long, 28 inches in diameter, and 8900 pounds. Need a diagram?

Note that being "exact" doesn't matter; Little Boy was a very conservative design, and allows for very large tolerances of error. The worst you'll get is a lower yield.

P.S. - I found this information in 5 minutes. Imagine someone actually dedicated to the cause of building a nuclear weapon...

And while we're at it . . .

[Maradine]

. . . let's be alarmist about it, because the info didn't exist anywhere else.

Re:And while we're at it . . .

[Phil Karn]

Not only that, much of the basic information about the nuclear fuel cycle and nuclear weapons was openly published by the US decades ago in the book The Effects of Nuclear Weapons.

Girlfriend

[RancidMilk]

Sounds like the same thing with my girlfriend. There is a tight bond, and when she is ripped off of me, lots of energy is released.

Only in America...

[RobertB-DC]

Only in our beloved country could someone think that this set of pages "sums up everything you might need to know if you wanted to refine nuclear fuel and build some atomic weapons." The information presented is what anyone with a high-school level knowledge of science should know. It's what anyone old enough to vote should know. When Bush claimed that Saddam was buying yellowcake from Nigeria -- even if it had been true -- it should have been obvious that without a lot of additional sophisticated equipment, it was about as useless as talcum powder.

On the other hand, I did get a nice refresher on the process. You do forget a few things in 20 years. And I can use the site as a resource for my kids, since they'll be too busy being taught "Intelligent Design" to be bothered with anything as mundane as chemistry and physics.

Not Even Close

[rgmoore]

Sorry, but that site isn't even close to "everything you might need to know" about building a Bomb. That's more like the 5 minute capsule summary. If you really want to know everything about building a Bomb but don't want to get a security clearance, the best place to look is Carey Sublette's Nuclear Weapon Archive. It's amazing just how much non-classified information it contains.

Article is an excerpt...

[DaedalusLogic]

From: "Nuclear Weapons for Dummies"

Chapters you'll get in the full book:

"Oppenheimer Shcmoppenheimer"
"Building Your First Triggering Device"
"Oops, Look at All the Fallout"

$14.95 US / $19.95 CAN

Errors I noticed

[Profane MuthaFucka]

-Enrichment levels for uranium meant for power plants is about 20% U-235, not 3%.
-The gun and implosion types of bombs aren't tied to the fissile type. You could use either type with either plutonium or uranium.
-They didn't mention confinement of the reaction on the gun type of bomb. If you don't try to hold it together with a heavy bomb casing, the bomb will blow itself apart as soon as fission begins, resulting in a really low yield.

If you were to try to build a bomb from these instructions, it wouldn't work.

You Forgot

[Greyfox]

This handy article on what to do with your plutonium once you've refined it. A must have for any organization interested in building such a device...

Inconsiderate

[rlp]

The Beeb could have at least provided a translation of the article in Farsi. :~)

Just another example

[Wapiti-eater]

of the decline of /. into a cespool of sensationalist pablum. This reads like it was published by the National Enquirer - not a "news for nerds" site. (maybe a 'news for n00bs' site)

Not news, not newsworthy, not even mildly interesting to anyone who was awake in 6th grade science class.

What's next? A front page story on the dangers and publich health threat of dihydrogen oxide?

Way short of "everything"!

[abb3w]

The article says nothing about the composition or manufacture of the membranes used in gaseous diffusion, how to handle the corrosive nature of U-hexaflouride, and mentions NOTHING about Laser isotope separation (let alone useful tidbits like the actual activation frequencies for U235 and U238 hex). The folk running the Manhattan project had better info than this even before they started. Buy a good introductory textbook and you'll get way better instructions with far more technical detail.

I guess the slashdot editor thought it was a slow news day or something....

everything?

[Vilim]

"The BBC has an article that pretty much sums up everything you might need to know if you wanted to refine nuclear fuel and build some atomic weapons."

This is true, in the same way

"Everything you need to know how to build a car is that pistons get pushed down by gas exploding which turns the crankshaft which turns the wheels"

is everything you need to know to build a car. Or

"Think of space as a sheet with masses as balls"

Is everything you need to know about general relativity

A general overview of anything is usually quite simple however in practise building a nuclear bomb is pretty difficult.

Re:How long?

[WolfWithoutAClause]

How long before /. gets shut down for distributing this information?!

Well, first it needs to start distributing information.

Re:Nothing new, check your encyclopedia

[Anonymous Coward]

most difficult, dangerous, and expensive processes known to man? sounds like finding a woman to be your partner to me

Next week he demonstrates

[crovira]

"How To Be A Gynacologist." (BIG geek appeal.)

But the next program in the series is a bit of a let down. Its on "How to reconcile the Russians and the Chinese"