The National Nuclear Security Administration's study on converting existing nuclear weapons for use against hardened and deeply buried targets is not intended to compete with the Defense Department's development of conventional "bunker busters," according to NNSA Administrator Linton Brooks. Rather, the study could give policymakers options for attacking targets that cannot be destroyed by conventional means, he said. "No one would ever wish to use a nuclear weapon" when a conventional one would do, Brooks said yesterday at a breakfast...