U.S. News and World Report: Thorium is a slightly radioactive element, a cousin of uranium. For the past four decades, in fits and starts, researchers have been testing it as a potentially attractive competitor to uranium as a source of nuclear fuel. Within the nuclear community, it’s won a small, devoted following. Up to now, it’s had little commercial impact. Today, however, thorium is getting a serious second look from some powerful global players. With interest in nuclear power soaring, thorium is being …