North Korea scientists mastering art of making nuclear arms, finds study

North Korean scientists have learned to build crucial equipment for uranium-based nuclear bombs on their own, according to evidence gathered by two American experts.

The analysis comes as experts have reported other signs that North Korea is activating or expanding its nuclear production facilities.

According to the New York Times, the new study focuses on production of advanced centrifuges, a technically difficult feat that the United States and others have tried to make harder for the North with a number of sanctions and bans on the export of sophisticated parts and metals.

If the North Koreans are successfully making their own parts, they would essentially invalidate much of the international strategy to force them to denuclearize and make it more difficult to monitor their production progress, the report said.

Joshua Pollack, one of the experts presenting the findings this week, said that hat means they would not be in a good position to spot the North expanding the program through foreign shopping expeditions and hat politics based on export controls, sanctions and interaction won't get much traction.

Pollack's findings in collaboration with Scott Kemp, an expert on centrifuge technology at M.I.T., will be presented on Wednesday during a conference organized by the Asan Institute for Policy Studies in Seoul.

Pollack said he and Dr. Kemp had analyzed such open-source data as scientific journals, news reports and propaganda from North Korea to find evidence that the country is learning - or has already learned - how to make such crucial centrifuge components and related technologies, the report added.