NATION IN BRIEF : WASHINGTON, D.C. : Severe Flaws Force Rebuilding of Sub

General Dynamics Corp. has discovered welding flaws so severe in the hull and internal structures of the Navy’s first SSN-21 attack submarine that the partly completed submarine will have to be disassembled and rebuilt, Defense Department officials said. Officials speaking on condition of anonymity said the problem is expected to delay delivery by as much as a year and cost tens of millions of dollars. Officials had no explanation of why the flaws, detected in mid-June, were not disclosed earlier. The submarine, known as the Seawolf, is intended to succeed the Los Angeles-class SSN-688.