Kim Jong-Il and Hugo Chavez got some bad news recently. The bad news for Kim is better for us than the bad news for Chavez. But for these guys we’ll take all the bad news we can get!

Simon Jenkins writes in the Guardian on what to do about a nuclear North Korea,

The stupidest policy would be one of economic sanctions. This never works, impoverishing peoples while rendering their rulers ever more embattled and paranoid. Nothing in history so props up dictatorship as economic siege. Ask Castro, Gadafy, Saddam and the ayatollahs. The North Koreans are poor beyond the power of economic squeeze. The proposal that China devastates the country by cutting its power would merely generate starvation and mass migration. Sanctions are cowards’ wars, cruel and counterproductive. In this case they are anyway too late.

It is tempting to conclude that the world must just get used to a new generation of nuclear states. The head of the International Atomic Energy Agency, Mohamed ElBaradei, estimates that some 40 countries are on the brink of being able to make nuclear bombs. As we live with 10, perhaps we must live with 40, struggling to reduce tension, minimise risk and help guard against accidents. A nuclear accident would not be the end of the world, certainly not in the sense that an east-west nuclear exchange would have been during the cold war. We handled that threat. Perhaps learning to live with nuclear power, in all its forms, will be the great challenge of the 21st century.

If this relaxed view is not viable in North Korea’s case (as opposed to Iran’s), there is only one sensible alternative. It is not to drag out a conflict through economic sanctions to eventual war, but to curb North Korea’s ambition in the simplest possible way. Sophisticated air power, useless in counter-insurgency, has a role in the “coercive diplomacy” of non-proliferation. Israel used it effectively against Iraq’s nuclear plant in 1981 and the US repeated the exercise with Operation Desert Fox in 1998 (though Bush and Blair later refused to believe it had worked). If Kim is the unstable menace he appears, his bomb-making capacity and missile sites should be removed at once with Tomahawk missiles. Fewer people would die that way than with any other pre-emptive response.

I heard a radio report today that the Bush administration is considering a blockade. It’s worth remembering that imposing a blockade has been recognized for hundreds of years as an overt act of war. To impose a blockade on NoKo ports is literally to make war upon the country. Whether a blockade is a good idea I don’t know. But I think Jenkins has painted the alternatives pretty well.

The chief executive of one of the UMC’s main general boards has denounced the nuclear test by North Korea.

“It is a deplorable act of aggression against the prospects of a more peaceful world,” said the Rev. R. Randy Day in a statement issued on the opening day of the annual meeting of directors of the Church’s General Board of Global Ministries.

More here.

North Korea announced that it had conducted a test of an atomic explosive devise Sunday night (EDT). The test was claimed to have been conducted entirely underground with no release of radioactive material into the atmosphere.

South Korean authorities said they monitored a seismic event of 3.6 on the Richter scale that was not a natural occurrence and corresponded in time to the claimed test.

Chester cites a news report, that seismic reading “could be caused by the explosion of the equivalent of 800 tonnes of dynamite.”

So was the test real or a hoax? Chester, same link, covers some territory on the subject but withholds judgment. One estimate of the TNT-equivalence I heard on a radio report was of 550 tons.

I don’t mean to belabor the point I have made before, but I was trained in the Army as a nuclear-target analyst. A yield of 550-800 tons (.55-.8 KT) is not too small by any means as an achievable yield. It does not require a lot of fissionable material, either, which is one factor militating against the “hoax” conclusion. If the test was a “proof of concept” test rather than one intended to validate an actual warhead, then it makes sense for the DPRK to use as little nuclear material as possible. They don’t get the stuff very easily.

It’s also worth pointing out that an atomic bomb of .6KT or so is no city flattener, but would work quite spectacuarly as a terrorist weapon. If detonated on the ground or from the top of a building, it would also result in serious fallout, increasing the terror effect and the number of deaths. Further, it would contaminate the terrain at and near ground zero for a long time. Cleanup and decontamination would be lengthy and very expensive. Imagine such a weapon being detonated in an American harbor.

So we should not be relieved that the apparent yield was so low. If the design yield was in the sub-kilton range, then this test was very successful.

On the other hand (you knew that was coming, since we have so little reliable intelligence on the DPRK’s program), the test could have been a fizzle. The design of a gun-assembled weapon (GAW) is pretty simple, as things atomic go. The Hiroshima was a gun assembled weapon. At one end of the bomb was a mass of uranium with the center section missing. At the other end of the bomb was the center section. Between the two uranium masses was a tube, basically a small cannon barrel. When the bomb’s altimeter fuze system determined that the bomb was the correct height above the target, it triggered a propellant charge behind the smaller uranium mass, shooting it at high speed into the larger section. A catalytic alloy of beryllium and polonium was set at the other end of the hole; this alloy is a neutron emitter just sitting on a table. When the moving center section smashed it at high speed, it flashed neutrons out like crazy and initiated the uranium chain reaction. Instantly, the whole bomb fissioned.

This design was never tested. Scientists considered the design so reliable, and the physics so well understood, that they thought no test was necessary. They were right. There are other ways to design a GAW that are even simpler, too.

However, measurements and velocities and timing must be precise. In an fission atomic weapon, one of the hard things to do is make sure that the fission process takes place uniformly enough throughout the atomic mass so that the fission chain reaction in one part of the mass doesn’t blow the other, unreacted mass away before it can chain. This is a greater issue, IIRC, in GAWs than in implosion weapons. (The Nagasaki bomb was an IW, in which the plutonium was arranged spherically around a beryllium/polonium sphere in the center. When the fuze system activated, the plutonium collapsed onto the center mass, which emitted neutrons under the pressure and impact. That made the whole thing go supercritical and the atomic explosion resulted.) But IWs are harder to make work because the timing is even more critical than in GAWs.

So the DPRK test may have been designed to yield a much larger explosion, and there are a multitude of design and manufacture flaws that can fizzle the detonation so that only a partial fission is achieved.

Or the DPRK carried out a msssive hoax, using hundreds of tons of conventional high explosive to create a seismic effect. But it’s hard to see the upside of this for them (not that they the most rational of actors, though).

DefenseTech explains how yields are calculated from seismic readings:

Estimating the yield is tricky business, because it depends on the geology of the test site. The South Koreans called the yield half a kiloton (550 tons), which is more or less — a factor of two — consistent with the relationship for tests in that yield range at the Soviet Shagan test site:

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.

The achieved yield of the Nagasaki bomb was indeed approx. 20 KT, of the Hiroshima bomb 13 KT. But we don’t know whether the DPRK used plutonium or uranium for this test. Uranium works very well for a GAW.

Using the US Geological Survey figure of 4.2 magnitude body wave of the seismic shock, giving a 1 KT achieved yield, actually buttresses the case that this test was not a fizzle, in my view. For battlefield purposes, say, against the South Korean or US forces on the peninsula, a 1 KT device is more usable than a 20 KT bomb. A 1 KT weapon is smaller, thus easier to conceal, and can be designed to be fired from existing artillery pieces, whether cannons or rockets. A Nagasaki-yield weapon would be of little military utility in fighting against South Korea or American forces. And you much more easily can get from a tested 0.6-1.0 KT proof-of-concept device to a usable terror weapon of the same yield, than from a test of a much larger yielding device.

DefenseTech concludes the test was a “dud.” I think it’s far too soon to be laughing aloud at Kimmy boy, myself.

Blue Crab Boulevard observes that North Korea is threatening “stronger physical actions” against Japan because Japan has barred NK sea vessels from Japanese ports.

Says BCB, “The West is being pushed closer to the brink. Time to wake up, people.”