North Korea appears to have restarted a nuclear reactor that is widely believed to have produced plutonium for nuclear weapons, the U.N. atomic watchdog said in an annual report, highlighting the isolated nation’s efforts to expand its arsenal.

The signs of operation at the 5-megawatt (MW) reactor, which is seen as capable of producing weapons-grade plutonium, were the first to be spotted since late 2018, the International Atomic Energy Agency said in the report, dated Friday.

Since early July 2021, there have been indications, including the discharge of cooling water, consistent with the operation, the IAEA's author of the report said of the reactor at Yongbyon, a nuclear complex at the heart of North Korea’s nuclear programme.

The IAEA has had no access to North Korea since Pyongyang expelled its inspectors in 2009. The country subsequently pressed ahead with its nuclear weapons programme and soon resumed nuclear testing. Its last nuclear test was in 2017.

The IAEA now monitors North Korea from afar, largely through satellite imagery

Commercial satellite imagery shows water discharge, supporting the conclusion that the reactor is running again, said Jenny Town, director of the U.S.-based 38 North project, which monitors North Korea.

No way to know why the reactor wasn’t operating previously – although work has been ongoing on the water reservoir over the past year to ensure sufficient water for the cooling systems, she said.

The timing seems a little strange to me, given the tendency for flooding in coming weeks or months that could affect reactor operations, Ms. Town added.

Last year 38 North said floods in August may have damaged pump houses linked to Yongbyon, highlighting how vulnerable the nuclear reactor’s cooling systems are to extreme weather events.


South monitors, but declines to comment on the Pyongyang's situation

North Korea is believed to be running multiple other covet uranium enrichment facilities. According to a South Korean estimate in 2018, North Korea might already have manufactured 20-60 nuclear weapons as well.

According to the most recent intelligence, the North also can carry the warheads over the distance of 10,400 kilometres reaching targets as far as in Australia and New Zealand, and most of the United States.

In recent months, North Korea has warned it would expand its nuclear program if the United States doesn’t withdraw its “hostile” policy on the North, in an apparent reference to U.S.-led sanctions and regular U.S.-South Korean military drills. Earlier this month, Kim’s powerful sister, Kim Yo Jong, said North Korea would bolster “absolute deterrence” to cope with intensifying U.S. threats.

Ms. Lee Jong-joo, spokesperson of South Korea’s Unification Ministry, stated Monday that South Korea was closely monitoring North Korea’s nuclear and missile activities along with the United States. But she declined to comment on whether Seoul was seeing signs that the North was reactivating its nuclear facilities.