North Korea has continued to produce bomb fuel while in denuclearization talks with the United States and may have produced enough in the past year to add as many as seven nuclear weapons to its arsenal, according to a study released just weeks before a planned second summit between the North Korean leader and US President Donald Trump.
However, the country's freeze in nuclear and missile testing since 2017 mean that North Korea's weapons program probably poses less of a threat than it did at the end of that year, the report by Stanford University's Center for International Security and Cooperation found.
Siegfried Hecker, a former director of the US Los Alamos weapons laboratory in New Mexico who is now at Stanford and was one of the report's authors, told Reuters analysis of satellite imagery showed North Korea's production of bomb fuel continued in 2018.
He said spent fuel generated from operation of the 5 megawatt reactor at its main nuclear plant at Yongbyon from 2016-18 appeared to have been reprocessed starting in May and would have produced an estimated 5-8 kg of weapons-grade plutonium.
This combined with production of perhaps 150 kg of highly enriched uranium may have allowed North Korea to increase the number of weapons in its arsenal by between five and seven, the Stanford report said.