Quick takes // By Ben FrankelNorth Korea’s conducts its third nuclear test

North Korea early Tuesday (EST) conducted its third underground nuclear test. The official North Korean announcement said the country has used a “miniaturized and lighter nuclear device with greater explosive force than previously” and that the test “did not pose any negative impact on the surrounding ecological environment.”

James Clapper Jr., director of U.S. national intelligence, issued a statement saying that the third nuclear test showed North Korea to be capable of producing nuclear devices with substantial explosive power. “The explosion yield was approximately several kilotons.”

The South Korean Defense Ministry said its sensors indicated the nuclear test had a yield of six to seven kilotons (about half the size of the bomb dropped in Hiroshima in August 1945). In 2006 North Korea tested a nuclear device with a yield smaller than one kiloton. Its second text, in 2009, with a yield estimated to be between two to six kilotons.

The yield of the test is only one measure of North Korea’s nuclear progress. There afre two other important measures: the  fissile material used and the device design.

Fissile material
North Korea has been trying for some time now to build nuclear weapons based on highly enriched uranium (HEU), rather than plutonium, which it used in the 2006 and 2009 tests. North Korea has an active uranium enrichment program.
North Korea has limited stocks of weapon grade plutonium. Experts say these stocks would be enough for six t eight Hirsohima-size weapon. Using HEU would allow North Korea to expand its nuclear arsenal more rapidly and without the constraints the limited supplies of plutonium would impose.

Device design
The North Korean official press statement said the test used a “miniaturized and lighter nuclear device with greater explosive force than previously.” This makes sense, since North Korea has been testing ballistic missiles of longer ranges, and a nuclear war head has to be miniaturized to fit on top of a missile.
If the North Korean statement is accurate, it means that the country is a step closer to marrying a long-range ballistic missile to a miniaturized nuclear warhead, making the country’s nuclear weapons threat that much more potent. Two months ago, in December 2012, North Korea successfully tested a multi-stage satellite launcher. A multi-stage missile that carries a satellite can also carry a nuclear warhead.

The test is the first under the country’s new leader, Kim Jong-un, and it comes on the day President Obama, in his State of the Union address, is going to call for deep reductions in nuclear arms. The president would call for bringing the number of deployed American weapons down to roughly 1,000, from the current 1,700. The START agreement signed with Russia in 2009 calls for the United States and Russia to reduce their arsenals to 1,550 nuclear weapons each.

Ben Frankel is the editor of the Homeland Security News Wire