North Korea appears to be testing nuclear detonators to prepare for another nuclear test, the presidential office here said Wednesday.
Deputy national security adviser Kim Tae-hyo told reporters, "We're watching what's happening at the Punggye-ri test site. It's unlikely that there will be a nuclear test in the next couple of days, but there's certainly a possibility after that."
Testing the detonators is an essential part of the development of nuclear bombs. In order to achieve symmetry in a nuclear blast, detonators each have to trigger within microseconds of one another.
Kim said the North has carried out about 130 high-explosive tests since the 1980s and six nuclear tests since October 2006.
Asked about the timing of the nuclear test, Kim said, "We don't know. Perhaps, the North Korean leader himself hasn't made a decision yet." But he added, "Considering that several rounds of high-explosive testing were conducted there over the last few weeks, the North seems to be in the final stages of preparation for a blast test."
It seems highly likely that the North is preparing to test small tactical nuclear weapons. Lee Chun-geun of the Science & Technology Policy Institute said, "In order to improve detonators for small tactical nuclear weapons, plenty of high-explosive testing is needed."
A ground-to-ground missile is being fired during a South Korean drill on Wednesday after North Korea's launch of three ballistic missiles. /Yonhap