North Korea recently turned over to the United States equipment found to be contaminated with traces of highly enriched uranium — HEU — apparently contradicting the country's stance that it never had such a program, FOX News has confirmed. ... "They got some 'splainin' to do," one U.S. arms control official said when first told of the discovery about a month ago, he recalled to FOX. However, North Korea claims the tubes were intended for use in the development of a conventional "artillery" weapon, sources told FOX News. ... Green told FOX News he believes the data supporting the existence...