Come for the politics, stay for the snark.
by Tim F| 45 Comments
This post is in: Foreign Affairs
Increasing signs suggest that the North Korea nuclear test may have been a failure.
AJ at Americablog comments, mostly riffing on this post as well as this one by the folks at Arms Control Wonk, who seem to know the nuts and bolts of nuclear testing better than anybody currently commenting.
Great if true, but no doubt the DPRK will try again. That takes for granted that the engineers who failed are allowed to try again and not reassigned to catching grenades or pharmeceutical experimentation.
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[…] Chinchillas to Baloon Juice. […]
[…] When the Bush administration pulled out of the Agreed Framework with North Korea in 2002, the main complaint was that the DPRK had a clandestine program to enrich uranium on top of its well-known and nearly bomb-ready work with plutonium. As an indisputable result of our pullout North Korea unfroze its plutonium activities and proceeded by many accounts to assemble several functional (or semi-functional) nuclear weapons. […]
Perry Como
You know, if Republicans were in charge we’d never even have to worry about North Korea testing nuclear weapons. This is just another reason why you can’t trust the Defeatocrats(TM) with national security and global stability.
Mr Furious
I wouldn’t be surprised if this is true. Though this morning it sure sounded like Russia had confirmed it (according to the BBC).
Punchy
Marshall says that the foreign press is running this “failure” tact, but–not surprisingly–Anything For Ratings (fomerly CNN) and other US media won’t touch that meme, for fear of losing the story’s fear-inducing potency.
Richard Bottoms
It’s only a dud if their goal wasn’t to embarass Bush with a giant fuck you while they continue to work towards a (more) successful test.
Tsulagi
What could be interesting will be to see how China acts after this. If they really don’t want NK to have nukes near them, they’ll come down hard on NK without our asking. If they’re okay with that, they’ll just bluster and continue to allow Bush to outsource our security interests to them. They have our best interests at heart.
If China really thought NK was a threat, or if Kim went off-the-charts crazy and directly threatened them or actually popped one on them, China would annex the place and not many would complain. These are the days of preemption, bitch. As a minimum, while they continue to build their military and strategic oil reserves, they can point to NK saying they’re the long-term threat not China. Works for them.
Lee
My dad used to work at the Nevada Nuclear Test Site (yes he really did). He was actually one of the last ones to leave when they stopped testing (he set up the system to monitor the radiation migration thru the ground/ground water).
Called him today to ask about it and he pretty much said the same thing that nuclear blasts have a very distinct seismographic signature (even the small ones) and that if the blast did not have that signature that it was either a dud or a fake (he thinks it was a fake).
He also said that many of the last tests in Nevada were done to help with a system that uses satellites to help detect nuclear blasts. He did not know if that was successful or not.
Steve
I think if it turns out to be a fake, it’s a lot more embarassing to North Korea than it is to Bush, to tell you the truth.
North Korea is not very savvy when it comes to PR – they’re kind of like the Iraqi Information Minister. They’ve actually got something in common with our present administration, in that they’ve spent so long spreading cheap propaganda that only a fool would believe, they don’t even realize the rest of the world isn’t going to fall for it.
I think it’s entirely plausible that they thought they could fake it and just bluster their way through. However, the more likely scenario is that it was an honest test which simply turned out to be a dud, and of course they have to act like it was a big success to avoid losing face.
Tom
You mean all that screeching at Huffington Post was for nothing?
Anderson
You should’ve quoted Arms Control Wonk:
It sure seems that if the Chinese wanted to, they could suggest to a few NK generals that a military junta, one that continued authoritarian rule while junking the nuke program and opening up NK to the world economy, would not be taken amiss, and is prevented from happening only by the persistent heartbeat of one Kim Jong-Il …
The Other Steve
I’m not a Nuclear Physicist, but how exactly do you have a dud atomic bomb? From the simplest understanding of the principles, the idea is to force the plutonium into critical mass, at which point the thing just goes off.
The atomics we dropped in WWII were relatively simple devices, presumably like what North Korea is trying to construct. That is you have one medium piece of the material, and a smaller piece, and an explosive charge which slams the two together to form critical mass.
I’d think it would either work, or not work. Not have a low-yield device.
The US plan for low yield nukes was talking about a 5 kiloton, and the way the debate sounded is it’s rather difficult to get that small of a yield in the first place. The WWII bombs were in the 15-20kiloton range.
Just curious, trying to understand. Maybe someone has a link to an article from an expert on that?
The Other Steve
Practice is never for nothing.
The Other Steve
I’m still thinking the likely scenario is they blew up something else to try to claim it was a nuke as part of their bluster.
The counter-proliferation(notice cool use of Boltonesque language!) scientists ought to be able to investigate this and determine if it was or wasn’t.
Punchy
Learned a new word today–“criticality”. I have no idea what it means, but something to do with the plutonium’s implosion before explosion thang. Have a feeling if the P-239 didn’t compress enough in all directions, that perhaps it failed to produce the self-sustaining nuclear decomposition…
ThymeZone
Well, if the purpose is to ping the US and find out how they are going to react to a test, you don’t need to stage a successful test to get the data you want. You can save a lot of money by announcing the test and then later leaking the fact that it was a “dud.” They got back their return on the ping for next to nothing.
DougJ
The failure of their test proves that the Bush policy towards North Korea is correct.
Tsulagi
Yes and no. For Hiroshima we used a gun assembly type design. A pipe bomb with a mass of HEU (not plutonium) at one end propelled into a mass at the other end of a capped pipe. The pipe was 6’ long for Little Boy. For this kind of device you need at least 20kg of HEU for any kind of pop.
Nagasaki, like designs today, was a much more complex implosion device. A core of plutonium that gets compressed by explosive forces within a sphere. When sufficiently compressed, you go big bang. Can get by with 3kg of plutonium as a minimum, plus the device is much smaller and lighter. This is what you need for a warhead on a missile such as Kim’s Dongs.
Perry Como
I think we need an investigation to find out when the Democrats knew about this nuclear test.
Pb
Wikipedia:
Kirk Spencer
TOS – one way it could be considered a dud is *IF* the bomb used a fission trigger to initiate the fusion reaction and “only” the trigger went off.
Which, based on yield, has a good chance of being what happened.
demimondian
Quick comments
(1) The Little Boy bomb contained about 11kg of U235.
(2) Modern gadgets are far simpler than the Fat Man device.
(3) It’s not actually the compression which is relevant, but rather the proximity.
(4) There are some physical limits due to the mass of plutonium, the speed at which thermal neutrons travel, and the time it actually takes for a nucleus to fission which provide a lower limit for the size of a first-generation bomb. I don’t know the figure (although I could probably estimate it), but it’s going to be roughly of the order of magnitude of a Nagasaki bomb. The DPRK device is disturbingly far away from that order of magnitude.
That *does not* mean that the device didn’t get a chain reaction going, just that the reaction was disrupted very early on.
Perry Como
That’s the most likely scenario. And chances are John Bolton personally disrupted the chain reaction. I didn’t see Nancy Pelosi trying to disrupt the chain reaction! Another reason why we have to trust Republicans with our national security.
ThymeZone
I definitely think that the physics of the thing is what we should be focussing on now.
Steve
That only works if the first stage of our response isn’t to verify whether or not a nuclear test actually occurred.
demimondian
Is that snark, or serious? Either way, I’m curious why you think so, or not.
Perry Como
Here’s a perfect example of why Democrats can’t be trusted with national security:
Senator Reid wants the President to cut and run from the North Korean strategy. At such a critical moment, cutting and running will show weakness. What we need to do is make sure that the President stays the course.
ThymeZone
Well, I suppose that “Hot Air” could be a slogan for a blog about thermodynamics …..
No wonder I got myself banned from here. I missed the whole damned point!
The answer to your question is: Yes.
chopper
i doubt that any country would be attempting a thermonuclear device as it’s very first go at a homemade atomic weapon.
i’m not sure about all this…if the thing was a real ‘dud’, it wouldn’t have made much of an explosion at all. maybe it blew itself apart before more than a very small percent of the material could undergo fission (the original ‘little boy’ only fissiled about 1% of the uranium it carried), which i would call a dud, but not in the way most people consider it.
or it was all faked from the get-go. dunno.
Hyperion
i like a population analogy.
U fission produces neutrons like people produce children.
(fission also produces energy which is what the seismic measurements detect.) the population will explode only if every couple produces more that 2 children that go on to produce (more than 2) children.
so part of the problem is giving birth to the children. but if infant mortality is high, the children will not live to procreate. so having lots of fission events is not sufficient. they must occur over a short time and the neutrons produced must go on to produce more fission events. it’s a positive feedback process that goes out of control. 3 kids produce 9 kids who produce 27 kids, etc.
simple geometric flaws can prevent the chain reaction from taking off…somehow the neutrons get quenched…they never find U nucleus to break aprat before they die. this is the infant mortality analogy. HEU is the equivalent of a very fertile couple; it’s capable of producing lots of neutrons.
Tim F.
A couple of points:
A failed plutonium detonation would not leave a seismic signature. I believe that explosives used in railway tunneling produce a bigger bang than some primer charges. So either the Norks set off a miraculously underperforming nuke or else they simply faked it. Some have suggested that the bomb only went off halfway. That could be true, I don’t know the physics that well. But barring that it looks to me like they tried to stage a nuke blast.
terry chay
The number I heard was half a kiloton. I don’t know about plutonium, but with uranium, critical mass creates an 11 kiloton explosion (Hiroshima).
terry chay
BTW my point was I think half a kiloton is large sounding for it to have been faked. Sounds like it didn’t reach critical because some of it predetonated or didn’t detonate.
The experts will have an answer for us in a couple days. Be patient. :-)
demimondian
Half a kiloton is too big for conventional explosives — it’s a million pounds of TNT, assuming completely efficient detonation. Possible, but very difficult. The US has done it, but I only know of once case, and that was with many years of careful preparation.
Far more likely, in my opinion, is a very poorly performing atomic device.
Darrell
What a surprise that the moonbats at Huffington Post blame it all on Bush
Yes of course, Iran and N. Korea were never a problem before Bush 43 was sworn into office.
Darrell
Now that’s the kind of candor I’d like to see from more liberals, talking about the Agreed Framework sham with N. Korea was a “victory”.
Anderson
And chances are John Bolton personally disrupted the chain reaction.
One could only wish.
chopper
it could have blown itself apart prematurely. the problem is, uranium gun-type bombs are known for that kind of behaviour. plutonium implosion-type bombs either go off or they don’t, the entire thing is based on all of the low- and high-explosives in the shell going off exactly right. anything other than exact perfect timing and it’s just a dirty bomb.
now, plutonium bombs are designed to take a sub-critical amount of Pu and compress it until it’s dense enough to undergo fission. so i can imagine a 1/2 kiloton plutonium bomb.
but if the seismic and radiation signatures are off, then they’re off.
Pb
The five stages of receiving catastrophic news: The White House is in denial on this one.
And incidentally, even if Snow is right in his speculation, this is all sure to piss off North Korea even yet still more, if that’s even possible. Now it’ll be interesting to see if The White House can get past denial and anger and into bargaining.
Steve
The basic difference between uranium and plutonium is that you can make a nuclear weapon a lot faster by processing plutonium. That’s why it was a diplomatic victory for us to enter into the Agreed Framework which kept North Korea from processing plutonium, even if they were cheating by enriching uranium. The uranium process, unless you have a zillion centrifuges, takes a very long time to actually get anywhere.
demimondian
Meh. Yes and no, Steve.
You can make a pure fission weapon *from preexisting Uranium* much faster than you can make one from Pu. You’ll pay a price — the weapon will be very inefficient, and not very reliable — but you can make a U-235 gun bomb with standard “off the military shelf” technology. Remember, the Manhattan Project didn’t even test Thin Man; they just dropped it, and it worked.
However, the process of accumulating uranium is slow and inefficient, and really needs significant natural deposits of uranium ore, not to mention a vast enrichment enterprise. Clinton et al. seem to have concluded that it would take many decades for DPRK to accumulate enough U235 to build a weapon. As usual, they also appear to have been right.
The alternative, making an implosion bomb from bred Pu239, is far harder. (And a third alternative, building bombs from bred U233, is harder still, although apparently possible.) Bred Pu is typically contaminated by Pu240, which spontaneously fissions at a high rate. That’s why Pu bombs use implosion.
Of course, it isn’t impossible that the DPRK *could* have built a gun bomb out of bred Pu. The result would have been exactly what we saw: a very low yield atomic explosion.
Detlef
The other Steve asked:
Neither am I but from what I´ve read in the last days, it is possible to have a dud bomb.
Nuclear Weapon Design gives a overview about the two different weapon designs.
All reports assume that North Korea used plutonium for its bomb. According to Reactor-Grade and Weapons-Grade Plutonium in Nuclear Explosives plutonium 239 is produced from uranium 238 in a nuclear reactor. If you leave the rods too long in the reactor, more and more plutonium 240 will be created as a byproduct.
(I´ve read somewhere that the rods were left two years in place? It true, that probably would be too long.)
IF that´s the case they maybe got too much PU-240 in their bomb. Pu-240 is bad because it naturally emits neutrons and can thus pre-initiate a chain reaction ( Spontaneous fission Pu-239: 7.01 fissions/s-kg; Pu-240: 489,000 fission/s-kg).
If they used plutonium, they had to use the implosion device .
If the implosion was a bit too slow then the plutonium 240 might have produced a “fizzle”.
Note: From what I´ve read on the Internet the estimates for the explosion seem to be around 550 tons of TNT. It was also mentioned that we don´t know the exact ground conditions. How large was the chamber, surrounding rock etc. So the actual explosion might have been a bit larger. Which would be consistent with the Department of Energy estimate that even a nuclear weapon from reactor-grade plutonium [and the resulting problems with PU-240] would have an assured, reliable yield of one or a few kilotons.
All of which is speculation from an non-expert! :)
Steve
I’m sure you know more than me, but I’m not sure what the difference is between your “vast enrichment enterprise” and my “zillions of centrifuges.” It kind of sounds like we made the same point, although I freely admit my wording may have been imprecise.
demimondian
I was whining about this sentence:
That’s really only true if you’re building the industrial plant. A uranium bomb itself is actually simpler to build.
Rudi
From Wiki a line about Hiroshima’s efficiecy:
It exploded about 600 meters (2,000 ft) above the city with a blast equivalent to about 13 kilotons of TNT (the U-235 weapon was considered very inefficient, with only 1.38% of its material fissioning),[10] instantly killing an estimated 70,000–80,000 people. The NDRK bomb was probably a bigger dud if not a fake.