Diplomatic sources said Wednesday that North Korea has upgraded some of the equipment at its nuclear facilities in Yongbyon since it expelled International Atomic Energy Agency monitors in 2002.

According to the sources, IAEA officials who visited the Yongbyon facilities late last month noticed some “changes” in the equipment installed in nuclear fuel rod production facilities and radiochemical experiment labs.

In particular, the IAEA officials found upgraded extraction devices in the radiochemical labs, which are considered facilities for the reprocessing of nuclear fuel. In addition, the fuel rod production facilities were found to be equipped with a new manufacturing system.

Meanwhile, the U.N. agency said in its latest report that North Korea had agreed to cooperate with its monitoring of the shutdown of the Yongbyon nuclear facilities in accordance with the six-way agreement of February 13th.