[Yonhap News Photo]
Pyongyang made a surprise announcement on January 6 that it successfully tested a hydrogen bomb in its fourth attempt. South Korea's Defense Minister Han Min-goo told parliament that "any meaningful" level of isotopes related to such a bomb has not been collected.
"Judging from the explosive power gauged by our measuring instrument, there was no big difference between (North Korea's) third and fourth nuclear test," he said.
A hydrogen bomb, also known as a thermonuclear bomb, uses more advanced technology to produce a significantly more powerful blast than an atomic bomb. Some experts said North Korea has been speaking rhetorically.
North Korea conducted underground tests to set off nuclear devices in 2006, 2009 and 2013, but outside experts suspect the North is short of achieving the capability to put a nuclear warhead on a missile, although it claimed to have acquired related technology.
Aju News Lim Chang-won = cwlim34@ajunews.com
reporter
Park Sae-jin
swatchsjp@ajunews.com
