N.Korean Nuke Test 'Likely in Mid-February'

Pundits cooling their heels as North Korea gears up to conduct another nuclear test now speculate that the test is likely to take place in the middle of the month.

The window for the test is limited now that preparations appear complete, due to the short lifespan of measuring devices. Including a super-high-speed camera, a thermal imaging camera, a thermometer and a barometer, they are usually installed in and outside an underground test tunnel.

But these state-of-the-art devices are susceptible to humidity and moisture.

An expert with a South Korean government-funded think tank said, "Generally speaking, you should conduct a nuclear test within two weeks if you have installed measuring devices in an underground test tunnel."

But these state-of-the-art devices are susceptible to humidity and moisture.

An expert with a South Korean government-funded think tank said, "Generally speaking, you should conduct a nuclear test within two weeks if you have installed measuring devices in an underground test tunnel."

Possibly to make it more difficult to predict the timing of the nuclear test, the North dug up a smaller separate tunnel to put the measuring devices in but has not yet set them up, some experts believe.

A staffer at the Korea Institute of Nuclear Safety monitors radioactive materials around the Korean Peninsula on Tuesday. A staffer at the Korea Institute of Nuclear Safety monitors radioactive materials around the Korean Peninsula on Tuesday.

Military sources have dismissed speculation that North Korea is going to test a hydrogen bomb. Ham Hyung-pil of the Korea Institute for Defense Analyses said there is no evidence that the North has acquired tritium, a material essential for the development of a hydrogen bomb.

Siegfried Hecker, a U.S. nuclear physicist who visited North Korea in 2010, was quoted by Yonhap News as saying the North could detonate a hydrogen bomb based on plutonium and highly enriched uranium.

It is doubtful how fast and accurately South Korea can determine the nature of the North's third nuclear test. Seoul needs to measure radioactive materials such as xenon and krypton within 24 hours after the nuclear test, since it is hard to determine based on seismic activity alone whether plutonium or uranium has been used for the test. The composition ratio in radioactive materials changes rapidly.

South Korea has radioactivity measuring devices, but the fallout is likely to reach the South only several days after the test.

Seoul and Washington therefore hope to obtain data with a WC-135 reconnaissance plane that will fly from the U.S.' Kadena Base in Okinawa, Japan to waters in the East Sea off Punggye-ri.

englishnews@chosun.com / Feb. 06, 2013 12:34 KST