NK nuke test?

[Dr Mordrid]

http://www.cnn.com/2006/WORLD/asiapcf/10/09/korea.nuclear.test/index.html

Update: the Russians estimate a yeild of 5-15 KT, with 15 KT being about the size of Hiroshima.

The Chinese and Japanese are very far from pleased.

[cjolley]

I don't know if this really makes a difference, but it may have been a dud.

http://www.defensetech.org/archives/002832.html

... Mb = 4.262 + .973LogW

Where Mb is the magnitude of the body wave, and W is the yield.

3.58-3.7 gives you a couple hundred tons (not kilotons), which is pretty close in this business unless you're really math positive. The same equation, given the US estimate of 4.2, yields (pun intended) around a kiloton.

A plutonium device should produce a yield in the range of the 20 kilotons, like the one we dropped on Nagasaki. No one has ever dudded their first test of a simple fission device. North Korean nuclear scientists are now officially the worst ever. ...

[Dr Mordrid]

1 KT is more problematic than a 5-20 KT as it typically indicates a more advanced design. The US artillery shell nukes (W-48) had yields down to 70-100 tons, and they sure weren't 'duds'.

All it takes for a Plutonium bomb is 1.1 critical masses to get yields as low as 10-20 tons, which is all you need as a proof of concept. 1 critical mass of Pu-239 weighs 10.5 kg and is 10.1 cm in diameter, so a touch more than that and you're in business.

People also think that spherical compression is the 'way' with Plutonium, but that's not the case. Opposed shaped charges with a non-spherical core and many other configurations are more common, and very useful for mini-nukes.

[KvHagedorn]

I wanna see your basement, Doc.. (looks for antirad bunny suit)

[cjolley]

Doc,

All that inplies that NK's first tested nuke was a sophisticated design.
That seems very unlikely to me given thier unsophisticated tech in every other field.

[Brian Ellis]

Don't underestimate them: they have some very talented scientists and engineers.

[cjolley]

We will know soon enough.
In order for it to be a credible threat they will have to vent the hole to let us get a sniff of the products of the blast.
If they don't do that my bet is that it was a ruse.

If they do then the small size of the blast would make it a bigger threat to us than if it had been big.

[Dr Mordrid]

Why in hell would they drop their shorts and show what they have?

From the tactical point of view it's better to leave an adversary in the dark as to your capabilities, especially once you've issued a threat to lauch a nuke missile at the US as they did this morning.

Brian is correct; they have a large number of very talented scientists and they got a head start from A. Q. Khan, Pakistans rogue nuclear weapons expert and arms dealer. He ran the Pakistani program, likely starting with enrichment tech stolen from URENCO (runs most of Germany's nuclear plants) and eventually sold the tech to many rogue nations including NK, Libya and Iran. The US forces in Afghanistan also found some of his documents in AQ caves.

Fortunately Libya saw the advantages of going legit, but NK and Iran need addressing in a very serious manner. You can bet Iran is watching what happens in/to NK very carefully to see where any policy weak spots are and how they can exploit them.

As to the size of a blast: a small, inefficient device has advantages;

1. That 1 KT bomb will still vaporize an area of 20,000-25,000 square meters (~5 acres for those in the US). "Small" is realtive when talking nukes.

2. easier to launch at a long range with modest rocket tech.

3. if a ground burst it could spread fallout consisting of vaporized materials, unexploded core and bomb casing over a very wide local area, depending on the winds.

Even a 1 KT bomb could make for a radiological nightmare if the core were also used to scatter a few kilograms of a long half life, but very hot, gamma emitting isotope like powdered Cobalt 60 (5.26 years vs. weeks for most fallout).

Co60 is used in radiation therapy machines and food/medical/industrial sterilzation with highly restricted exposure fields and careful physical isolation and containment (sealed in another material).

IF one were sustain a significant whole body exposure to Co60 for just a few minutes they'd be toast; the lining of their gut would rot off, the brain and other neurological tissues would suffer severe damage and their bone marrow would die....and so would they in a rather short time.

Now imagine one of those landing on the US west coast. It's so highly populated that no matter where it landed it would be a disaster that would make Katrina etc. look like a light squall. No sophisticated guidance system necessary to start a whole lot of trouble.

[cjolley]

Nukes aren't used for tactics. They are used for strategy.
And especially by NK who wouldn't dare really use them.

If they really do have them they will want us to know it.
Doubt works backwards in this case.
Maximum concern is if they for sure have them.
Doubt can only server to lower our concern.

My dad wrote the programs we used for planning our nuke attacks on the USSR for years.
He told me that he always assumed the the Soviets knew the details of everything he wrote. He just figured the better job he did at it, and the more they knew, the less likely they were to attack us.
That's just the way nuke arsenals work.

On the other hand, if NK really doesn't have them, then their best bet at achieving the same deterrence is to pretend they do.
Not as good a deterrent as really having them, but not nothing if they can put on a good show.


Israel is in a different position. They don't want the huge cost of sanctions, so they credibly let it be known the they have the bomb, but don't do anything overt that would force sanctions.

NK doesn't care about sanctions, at least not anything anyone has thought of yet.
They are playing the US and China's interests against each other. The US doesn't want NK to have the bomb because a, because their leader is crazy, and b, we don't want anyone else to get the tech and NK is bad about selling the bad guys war tech.
China doesn't want NK to have the bomb, but wants millions of refugees from a failed NK even less.

With a fake test, if NK got really worried that China had decided the bomb thing overrode the nuke thing then they could prove it was a fake quickly and save themselves.

So they might consider themselves ahead by having the bomb, but putting on a fake test.
Or, any number of permutations of possibilities like that.

[Dr Mordrid]

Sorry, but I disagree. This isn't the cold war and cold war tactics like MAD don't apply.

We're dealing with a rogue nation where they want to instill doubt in order to blackmail their way into getting what they want, much like a game of poker.

You don't show your cards in poker.

[cjolley]

Sorry, but I disagree. This isn't the cold war and cold war tactics like MAD don't apply.

...

Are you saying you think they might actually shoot a nuke armed missile at the US?
Why would they do that?
It would have a high probability of failure, but a 100% probability of a military response that would end the regime.

The rules of this poker game allow you to tell your opponent that you have the royal flush and that if they don't give you the pot you will lay it down.
Why bother with something that might be perceived as a bluff, when you have the cards in hand?

I still think that maximum value could be extracted if they proved they had the bomb, and that increasing doubt would just lead to decreasing the value the blackmail could extract.

[Dr Mordrid]

NO, I'm saying they'll threaten/bluff....something they already did this morning.

That said are you really that sure about what that whacked out nutball might do some night when he's hopped up on his Johnny Walker & coke? I'm not. We're not dealing with someone who has a full deck here....

Personally my idea of an ideal "settlement" is for China to move in with guarantees that the US, Japan etc. will provide the humanitarian relief in situ so they don't end up with refugees crossing their border, which is their main concern when it comes to military ops.

China's in a tough spot. They want stability after all their recent economic gains, and refugees would upset that. Hence the humanitarian aid in situ.

On a wider front the last thing we need is for SK, Japan, Taiwan etc. to decide that they need to go nuclear in response. Japan alone has 10 tons of Pu on hand, so they could do it in weeks or months and make no mistake...they are in a panic. Taiwan and SK also have Pu stores.

With all the old rivalries this makes resolving the situation fast and for certain an urgent priority.

Talk about throwing a match into the dynamite shed

[cjolley]

Heh, I was just about to add a caveat about his crazyness.

In fact that may be the one factor that could push China into cooperation with regime change despite their fears of refugee debacle.

[RedRed]

the news today said that teh Russians confirmed it was between 5 and 15 kilotons.

[edit] whoops Dr M - missed your update on post #1, srry!

[cjolley]

It's looking more like a dud:
(NB. in the physics sense)

http://www.cnn.com/2006/WORLD/asiapcf/10/10/korea.nuclear.test/index.html

NEW YORK (CNN) -- The United States believes North Korea attempted to detonate a nuclear device and that "something went wrong," a U.S. government official told CNN Tuesday.
The official confirmed North Korea informed the Chinese government prior to the test that it would be a 4 kiloton nuclear device.
The official added that the unexpectedly small blast, of a half kiloton or less, indicated "something went wrong."
Nuclear tests in 1998 by India and Pakistan were about 24 to 50 times as powerful - or in the 15 kiloton range, according to the Federation of American Scientists.
The United States still cannot say for sure the underground detonation was a nuclear blast; the working assumption is that it was, but not very successful, the official said. (Dud or deception? Read the full story)
Another U.S. official said it is possible North Korea may attempt a second test, but cautioned there has been no evidence of any preparations at another test site.
"I would not say we expect it," the official said on condition of anonymity because he is not authorized to speak publicly, "but it would not be a total surprise."
Russia's Defense Minister said Tuesday that his agency has estimated the power of the explosion at between 5 and 15 kilotons.
But the U.S. intelligence community is sticking by an estimate that the blast was approximately a half kiloton, or even less, although it's possible the hardened tunnel in which the test took place could have "muffled" the seismic waves, an official told CNN.
...

http://www.cnn.com/2006/WORLD/asiapcf/10/10/korea.building.bomb.ap/index.html

PARIS, France (AP) -- Was North Korea's nuclear device a partial dud?
That is one of several theories that Western experts say might explain the apparent low explosive force of the communist nation's first declared nuclear test.
Other suppositions are that North Korea deliberately chose a small device to save its limited stocks of bomb-making plutonium or that it somehow muffled the shockwaves from the underground blast to make it appear smaller than it was.
Even if North Korea got helpful pointers from nuclear-capable Pakistan, as many experts suspect, the technology of efficiently splitting atoms to make a controlled explosion is still tricky for novices to master. For North Korean scientists, working largely in isolation, that could be especially true.
"The devil is in the details," said French nuclear proliferation expert Bruno Tertrais. "It's like cooking. The fact that you have the recipe does not make you a chef."
...