With the announcement by state media that its main nuclear facility has resumed normal operations, North Korea’s atomic weapons program is back in the public eye.
The news, reported by the Korean Central News Agency on Tuesday, dovetails with a report released in April by the Institute for Science and International Security, which cited satellite imagery as evidence that the facility’s plutonium reactor was back online.
The Yongbyon nuclear complex was shuttered in 2007 as a result of international denuclearization talks involving the United States, China, Russia, South Korea and Japan. Then, in 2013, at a time of elevated tensions with the U.S. and South Korea, Pyongyang declared its intention to restart the facility.
In a typically bellicose statement on Tuesday, the head of the country’s atomic energy agency warned that Pyongyang was ready to deploy nuclear weapons against the U.S. at “any time” if it didn’t desist with its “reckless hostile policy.”
North Korea definitively answered the question of whether it possesses atomic weapons when it carried out its first nuclear test in 2006. But what remains far less clear to this day is just how many such devices it may have.
Estimates vary significantly: In April, The Wall Street Journal cited unnamed Chinese experts as saying Pyongyang could already possess 20 warheads; the School of Advanced International Studies at Johns Hopkins University has estimated 10-16 devices.
Jeffery Lewis, the founder of Arms Control Wonk.com, told The Diplomat that a dozen warheads is probably a safe bet.
“I just estimate based on the amount of plutonium — call it a dozen weapons with a fair amount of uncertainty,” he said.
Yet, that estimate does not account for North Korea’s parallel uranium enrichment program, which Lewis described as a “major unknown.”
Uranium enrichment facilities are easier to conceal than plutonium-based reactors, according to experts. With access to North Korea heavily restricted and the full extent of its capabilities unknown, precise estimates are beyond reach.
In April, nuclear proliferation expert Siegfried Hecker, who has visited Yongbyon multiple times, outlined some of the challenges of gauging the reality.
“Developing these estimates is not an exact science,” he told the Center for International Security and Cooperation at Stanford University. “There are huge uncertainties in estimating the enrichment capacity that is likely present at covert sites. One particular problem is the difficulty in assessing how much indigenous capacity North Korea has to make the key materials and components for centrifuges.”