N Korea nuclear capabilities back under spotlight

Analysts say the North has come a long way in developing nuclear warheads and long-range rockets, through nuclear tests in 2006, 2009 and 2013, and a series of rocket tests, disguised as satellite launches.

On Monday, Pyongyang hinted at the possibility of another rocket launch on October 10 to mark the 70th anniversary of the founding of its ruling Workers’ Party. That action would further escalate the North’s missile threat, and Seoul has stepped up its diplomacy to forestall it.

Since its 1998 test of the Taepodong-1 missile, the North has carried out five long-range rocket tests. Experts say the latest, in 2012, demonstrated that its missiles can travel some 10,000 kilometres – far enough to reach the US mainland.

Apart from the land-based platform, the North has been developing its nuclear-capable submarine system, culminating in a claim last May that it had test-launched a ballistic missile from a sub.

The reclusive state is also reckoned to be steadily accumulating weapons-grade fissile materials through its plutonium-based nuclear programme and uranium enrichment activities to build nuclear warheads. On Tuesday, the North’s Atomic Energy Institute chief claimed that the North had restarted all nuclear facilities, including its five-megawatt reactor and uranium enrichment factory at its main Yongbyon nuclear complex.

Seoul’s Vice Foreign Minister Cho Tae-yul confirmed at a general meeting of the International Atomic Energy Agency on Tuesday that the North has been steadily running the nuclear reactor at the Yongbyon facility and expanding the facilities for uranium enrichment.

The main five-megawatt reactor is the North’s core facility to produce weapons-grade plutonium. The reactor, should it be fully operational, can produce 6 kilograms of plutonium, enough to build one nuclear warhead, analysts say.

The North is believed to have accumulated some 40 kilograms of plutonium after it reprocessed spent fuel rods at least three times, in 2003, 2005 and 2009, according to Seoul officials.

Amid its efforts to produce plutonium-based bombs, the North has also been striving to advance its uranium enrichment programme, reportedly since the mid-1980s. 

The regime claims it has some 2,000 operational centrifuges capable of producing 40 kilograms of highly enriched uranium (HEU) each year. To produce one HEU bomb, more than 15 kilograms of HEU is required.

Should the North carry out another nuclear test, it could be of a boosted fission weapon, called a “1.5-generation” nuclear bomb, experts say. The development of this weapon is known to be a preliminary step toward the production of a hydrogen bomb – a “second-generation” nuclear weapon.

Amid growing speculation over the North’s fourth nuclear test, the US-based Institute for Science and International Security says that a new facility under construction at the Yongbyon complex appears to be designed to separate isotopes from spent fuel that can be used to produce powerful nuclear weapons.

The North has pushed for its nuclear programme under its so-called Byungjin policy of simultaneously developing its economy and nuclear arms. The North already describes itself as a nuclear power state in its constitution, a status that the US and South Korea say would never be accepted.