Vienna: North Korea appears to have restarted the operation of its main nuclear reactor used to produce weapons fuels, the UN atomic agency said. The 5-megawatt reactor is widely believed to have produced plutonium for nuclear weapons and is at the heart of North Korea's nuclear programme, the International Atomic Energy Agency (IAEA).
The UN atomic agency said it is "deeply troubled" by indications that North Korea appears to have restarted its Yongbyon nuclear reactor.
Responding to journalists' questions, the UN Spokesperson Stephane Dujarric, said on Monday that the Secretary-General was aware of the reports "and concerned by the latest developments."
"He calls for the DPRK to refrain from any nuclear weapons-related activities and to resume talks with the other parties concerned.
"Diplomatic engagement remains the only pathway to sustainable peace and complete and verifiable denuclearization of the Korean Peninsula."
In its annual report, issued before a meeting of its Member States, the UN-convened atomic energy watchdog said the reactor has been discharging cooling water since July, suggesting it is operational.
The report said the duration of that apparent work - from mid-February to early July - suggested a full batch of spent fuel was handled, in contrast to the shorter time needed for waste treatment or maintenance.
"The new indications of the operation of the 5MW(e) reactor and the Radiochemical (reprocessing) laboratory are deeply troubling", and a clear violation of UN Security Council resolutions, it said. The report also said there were indications of mining and concentration activities at a uranium mine and plant at Pyongsan.