A light-water reactor could provide more weapons-grade plutonium, abetting the North Korean leader Kim Jong-un’s vow to expand his nuclear arsenal.
In what would be a fresh breach of United Nations sanctions, a new reactor in North Korea’s main nuclear complex appears to have gone into operation, providing the country with a potential source of additional plutonium for its growing nuclear arsenal, according to the United Nations’ nuclear watchdog.
Since mid-October, the International Atomic Energy Agency has observed a strong water outflow from the cooling system of the new light-water reactor, or L.W.R., that North Korea has been building in Yongbyon, north of Pyongyang, Rafael Grossi, the director general of the agency, said in a statement on Thursday.
“The discharge of warm water is indicative that the reactor has reached criticality,” Mr. Grossi said. “The L.W.R., like any nuclear reactor, can produce plutonium in its irradiated fuel, which can be separated during reprocessing, so this is a cause for concern.”
The observations detailed in Mr. Grossi’s statement are another strong indication that North Korea has been accelerating its nuclear weapons program while its talks with the United States remain stalled and while the Biden administration is preoccupied with other crises around the world, including the wars in Ukraine and the Gaza Strip.