After President Clinton took office, the Energy Department allowed two of its most sensitive nuclear weapons labs to halt background checks on foreign guests to cope with soaring numbers of visiting Chinese and Russian scientists.
Officials now concede the move was a security blunder.
While direct evidence has not emerged of espionage by the visitors, congressional investigators found at least 13 scientists with suspected foreign intelligence ties were allowed into the labs without proper CIA or FBI scrutiny. Five of those scientists were allowed into the Sandia lab at Albuquerque, N.M., while eight visited the Los Alamos lab, also in New Mexico, that U.S. officials believe has been a target of Chinese espionage for more than 20 years, congressional investigators said. Security checks, mandatory before 1994, were reinstated last November amid growing Clinton administration worries about Chinese espionage at the government's premier weapons labs. The administration made it a priority after the Cold War to open up the once highly secretive weapons labs and expand their nondefense research programs. The surge in Russian visitors stemmed from an urgent need to help improve Russia's safeguards on nuclear material to keep it from terrorists or antagonistic states.