(Yonhap Interview) Uranium bombs expected to account for 60 percent of N.K.'s nuclear arsenal: think tank chief 2015/03/15 09:56 TweetFacebook ShareGoogle +1 ReduceEnlargePrint By Chang Jae-soon WASHINGTON, March 14 (Yonhap) -- North Korea is estimated to have up to nine nuclear weapons built with highly enriched uranium, and uranium bombs could account for up to 60 percent of the North's nuclear arsenal feared to grow to up to 100 weapons in five years, an American expert said. David Albright, a top nuclear expert who heads the Institute for Science and International Security think tank, spoke about the forecast in an interview with Yonhap News Agency, saying highly enriched uranium is easier to make than weapons-grade plutonium.