North Korea has nuclear bomb, would-be defector claims: report

[NNN0LHI]

http://www.khaleejtimes.com/DisplayArticle.asp?xfile=data/theworld/2005/July/theworld_July562.xml§ion=theworld&col=

SEOUL - A defector claiming to have been in the North Korean parliament said the communist state has produced a nuclear bomb and attempted to sell missiles to Taiwan, a South Korean magazine reported on Wednesday.

South Korean intelligence authorities declined to comment on the report in the Monthly Chosun, which said that the defector, a man believed to be in his 70s using the alias Kim Il-Do, defected to the South in May.

“North Korea has built a one-tonne nuclear bomb by using four kilogrammes of plutonium,” he was quoted as telling the National Intelligence Service (NIS), South Korea’s spy agency.

The North was now seeking to miniaturize the bomb to make it more reliable as a weapon, he reportedly said. The man claimed he had been in the North’s parliament and had worked for the Marine Industrial Institute.

[tocqueville]

1. maybe they'll get a Nobel Price...

"Weapons-grade plutonium must contain no more than 7% Pu-240; this is achieved by only exposing U-238 to neutron sources for short periods of time to minimize the Pu-240 produced. The critical mass for an unreflected sphere of plutonium is 16 kg, but through the use of a neutron reflecting tamper the pit of plutonium in a fission bomb is reduced to 10 kg, which is a sphere with a diameter of 10 cm."

(wikipedia)

so with 4kg of Pu = no critical mass. It would not even fart, maybe you could fry an egg on it (don't try that at home)

then why sell missiles to Taiwan ? just to piss off China ?

[punpirate]

3. Without getting into too much detail...

... 4 kg is enough. Do a search for Dr. Theodore Taylor. Some of the stories about him may explain why it is enough.

Cheers.

[tocqueville]

4. I don't get it

need more details. I checked him

Dr. Taylor would develop the smallest fission bomb of its time, Davy Crockett, which weighed less than 50 pounds. (By contrast, Little Boy, dropped on Hiroshima, weighed almost 9,000 pounds.) At the other extreme, he designed Super Oralloy, which was at the time, Mr. McPhee wrote, "the largest-yield pure-fission bomb ever constructed in the world."


Background on Suitcase Nukes

A "suitcase" bomb is a very compact and portable nuclear weapon and could have the dimensions of 60 x 40 x 20 centimeters or 24 x 16 x 8 inches. The smallest possible bomb-like object would be a single critical mass of plutonium (or U-233) at maximum density under normal conditions. The Pu-239 weighs 10.5 kg and is 10.1 cm across. It doesn't take much more than a single critical mass to cause significant explosions ranging from 10-20 tons. These types of weapons can also be as big as two footlockers. The warhead consists of a tube with two pieces of uranium, which, when rammed together, would cause a blast. Some sort of firing unit and a device that would need to be decoded to cause detonation may be included in the "suitcase."


I think that 4 Kg (8 pounds) of Pu is too little, but I can be wrong

[punpirate]

6. The Davy Crockett was mostly explosive...

... not much plutonium in it, which should provide a hint.

The trick with plutonium is that because it's a fast neutron emitter, it usually requires implosion. In other words, a sub-critical mass is reduced in size (and cross-section) by a controlled explosion--it's squeezed into a smaller and smaller ball in a matter of microseconds until it reaches criticality (when neutron production and capture are sufficient for a chain reaction).

So, it's possible to start with a smaller sub-critical amount and still get it to reach criticality by imploding it into an even smaller ball, and by using what's known as a reflector with very high neutron reflectivity.

I was hoping you'd find the quote about one of Taylor's last designs which was informally known as the "PP Shot," short for "puny plutonium." That was, at the time, the smallest successful nuclear weapon, and the PP in the name was meant to imply that the plutonium core was little bigger than a BB.

Gun-type bombs work differently, and plutonium isn't really suitable for them--in the time it takes to bring the two subcritical halves together, because of those fast neutrons--too many neutrons escape to bring the core to full criticality. (That said, Taylor, or his successors, did manage to combine aspects of both implosion and gun-type weapons using plutonium, and these were sometimes used in artillery shells--the method was known as linear implosion:



This artillery shell had a yield of 72 tons. So, it is possible to make quite small plutonium weapons.

Cheers.

[oasis]

2. Will Rummy & Cheney set this guy up with a Judith Miller interview?

:shrug:

[Commie Pinko Dirtbag]

5. To Taiwan?

Jesus. China would ream their a-holes so bad it wouldn't even be funny.

I smell bullshit.