North Korea is believed to have shut down its nuclear reactor at the Yongbyon complex, starting a process that could lead to the production of more weapons-grade plutonium, South Korean officials said on Monday.
“We are treating this matter very seriously,” Kim Sook, a senior South Korean foreign ministry official, said. “We learned of the halt to operations, and have confirmed it through various means,” Mr Kim told KBS Radio. “I think we'll have to deal with the suspension of the 5MW reactor as a weighty issue.”
However, Selig Harrison, a US analyst at the Center for International Policy with unusual access to the North Korean leadership, said he was told by top officials in Pyongyang this month that the reactor needed to be shut down for normal maintenance. The unloading of the rods would take several months, he said.
North Korea was willing to freeze its nuclear arsenal at current levels if the US made it clear, in public or private, that it had no intention of fomenting “regime change” in Pyongyang, Mr Harrison told the Financial Times.
Unloading the fuel rods while proposing a freeze was seen by North Korea as strengthening its diplomatic hand in the suspended six-party negotiations mediated by China, he added.
North Korea declared in February that it had made nuclear weapons and was withdrawing from multilateral talks on the issue. North Korea has repeatedly threatened to build more bombs to develop the deterrent it says it needs to protect itself from the US.
After shutting down the reactor, the 8,000 spent fuel rods can be removed and the plutonium extracted for reprocessing. North Korea claims to have “weaponised” the plutonium from the previous batch of rods. This could have yielded up to eight nuclear weapons.
North Korea had undertaken a review of its policy and decided that dismantlement of its nuclear programme the key US demand could only be discussed after normalisation of relations with the US, Mr Harrison said.
The US has said it has no intention of attacking North Korea, but has not ruled out the possibility of engineering a change of regime. The US also demands complete dismantlement and the fulfilling of other military and political conditions before relations can be normalised.
The White House on Monday responded cautiously to the reports, apparently uncertain how to interpret North Korea's latest move. It again urged the communist state to resume negotiations.
Asked if the Bush administration was considering carrying out its threat to take the issue to the UN Security Council, Scott McClellan, White House spokesman, said that was “certainly one possibility”. But he was not aware of a timeframe for the next diplomatic action on the part of the US.
International experts believe the North has reprocessed enough plutonium to build about a half-dozen nuclear bombs, but it has not performed any known atomic tests that would confirm its arsenal.