Now, this week, we have a third report from Stanford University’s Siegfried Hecker, Robert Carlin, and Elliot Serbin concluding that Pyongyang’s nuclear weapons program remains highly active in the midst of denuclearization talks with the United States. The three nuclear experts observe that North Korea has likely produced an additional 5-8 kilograms of weapons-grade plutonium and about 150 kilograms of weapons-grade highly enriched uranium last year. – The National Interest