What if the North Korean nuclear test wasn’t a dud?

More people are questioning whether the North Korean test was successful. Why? Maybe because no one wants to consider the alternatives:

  • If the explosion was nuclear and successful, the relatively small seismic shock suggests the yield was quite small, much smaller than the sweet spot of 15-20 kilotons most countries have used for their first nuclear tests. Designing smaller nukes is more difficult and normally done after testing larger devices. If North Korea already has small nukes, then North Korean’s nuclear program is more advanced. This could also suggest that North Korea is getting help from other countries who already have nukes or want nukes.
  • If the explosion was nuclear and relatively large yield, then North Korea designed a test site that effectively shields the true magnitude of the nuke. Although I’m way over my head here, the seismic shock is dependent on both the yield of the bomb and the coupling of the blast to the ground. Apparently, using a very large underground chamber is one way of decreasing the coupling. In this case, then the world’s visibility into North Korea’s nuclear program will be more limited.

Or, maybe the world knows the yield was large, the test was successful, and is just denying Kim Jong-il the congratulations he desires. ;-)

Was North Korean Nuclear Test a Fizzle?

Time to learn a new word: fizzle.

“Either this was a deceit using a few hundred tons of chemical high explosives or it was a nuclear device that did not go as intended,” said Bob Puerifoy, a former Sandia National Laboratories weapons executive. “I won’t call it a dud — a few hundred tons of explosives is not a dud — but a fizzle. And the designer probably has been shot by now.”

Was North Korean nuclear test a dud?

North Korea claims to have successfully tested a nuclear bomb and is awaiting congratulations. Even if the world had wanted North Korea to test, are kudos warranted?

Previously, North Korea caused a 2.3 magnitude seismic event using two metric tons of TNT. The event yesterday was magnitude 4.2, just about 100 times as powerful. Would that be equivalent to 2 metric tons X 100 = 0.2 kilotons TNT? If so, that’s not anywhere near the expected 20 kilotons of a nuclear test.

These are off the cuff questions by someone who has just enough knowledge to look stupid on the Internet. ArmsControlWonk has real equations, real knowledge, (a real funny picture) and comes to the conclusion that the test was a dud. Oops!

Update: Donald Sensing at One Hand Clapping says it’s too early to call the test a dud. North Korea may have design a small yield nuke intentionally, in which case the test could be a success. Or North Korea may have used a ton (actually, quite a few tons) of conventional explosives in an attempt to fool the world.

Update 2: Russia claims the test’s yield was between 5 and 15 kilotons, not the 0.550 kilotons as measured by South Korea. Russia also claims North Korea warned them about the test two hours before it happened.

Update 3: U.S. intelligence agencies are questioning whether the explosion was nuclear.

“We’re still evaluating the data, and as more data comes in, we hope to develop a clearer picture,” said one official familiar with intelligence reports.

“There was a seismic event that registered about 4 on the Richter scale, but it still isn’t clear if it was a nuclear test. You can get that kind of seismic reading from high explosives.”

The underground explosion, which Pyongyang dubbed a historic nuclear test, is thought to have been the equivalent of several hundred tons of TNT, far short of the several thousand tons of TNT, or kilotons, that are signs of a nuclear blast, the official said.

The official said that so far, “it appears there was more fizz than pop.” (Source)