Both U.S. senators from New Mexico have expressed deep reservations about the Department of Energy's plan to polygraph as many as 12,000 nuclear employees and want the program re-examined, saying it could unfairly damage careers and harm rather than help national security.

Sen. Pete V. Domenici (R-N.M.) said last week in a letter to Energy Secretary Bill Richardson that he is concerned about the reliability of the so-called lie detector tests that may be given to nuclear scientists and administrators across the country, including many in his state, home of the Sandia and Los Alamos National Laboratories.

Domenici told Richardson that "false positive" results could "overload any system you devise to handle them." He urged the energy secretary not to "seek large scale expansion of the program" and to stick to a far more limited approach authorized last week by Congress in legislation creating a new nuclear weapons agency.

Sen. Jeff Bingaman (D-N.M.) went further, saying in a separate letter to Richardson that the department should not implement any polygraph program until a government commission studies its impact on science at the national labs.

Bingaman also called on the National Academy of Sciences to review the reliability of polygraph examinations before any program is implemented.

"I am concerned that persons who are judged to have 'failed' a polygraph screening will not be easily cleared, as this would involve proving a negative," Bingaman wrote. "The latter will, in my opinion, be particularly difficult to do, judging from the partisan atmosphere in which DOE security issues have been treated over the last year."

Richardson proposed the aggressive polygraph program in response to allegations of Chinese espionage at Los Alamos, where the government's prime suspect, Wen Ho Lee, a Chinese American physicist, has been fired from his job but not charged with any crime.

Attorney General Janet Reno and FBI Director Louis J. Freeh told congressional committees last week that they are widening the investigation to include other potential suspects at additional weapons and defense facilities and have beefed up investigative resources.

Reno and Freeh said they decided to expand the investigation after concluding that the initial probe was botched by FBI agents and Department of Energy officials who focused prematurely on Lee as the likely source of classified warhead design information apparently obtained by China.

It remains unclear how many people might be investigated as potential suspects in the expanded probe. Government officials have indicated that they do not, at present, have any hard evidence against specific individuals. Hundreds of employees in the Energy and Defense Departments and at private defense contractors have had access to warhead designs.

At Los Alamos, meanwhile, one of three laboratory officials disciplined for mishandling the espionage investigation fired back in a letter to Los Alamos Director John C. Browne, saying the case against Lee was flimsy from the start and badly mishandled by officials in Washington.

Robert S. Vrooman, the laboratory's former director of counterintelligence, said he decided to allow Lee to continue working at the lab's top secret X Division in 1997 with concurrence from FBI and DOE officials because the evidence against Lee was scant and removing him could have unfairly damaged his reputation.

Vrooman, who retired in March and was recently stripped of a consulting contract as punishment, said he had handled 30 other counterintelligence cases at Los Alamos over an 11 year period, and in none of those cases was a scientist's name leaked to the press.

"In all of the above cases, there was more to suggest impropriety than there was in the Lee case," Vrooman said. "I really expected that the FBI would quickly realize that Lee was the wrong suspect and expand the investigation to a larger population."

Department of Energy officials have not said how long it will take them to consider public objections to their polygraph proposal and produce final regulations. But both Domenici and Bingaman, who play leading roles in Congress overseeing the department, have made it clear that they do not believe polygraph examinations should be used in a widespread search for spies.

Domenici said polygraph examinations produce "false positives"--results that indicate a subject is being deceptive even when he or she is telling the truth--about 10 percent of the time.

Bingaman said the proposed polygraph program "will make it much more difficult for the DOE laboratories to attract and retain the best and brightest scientific and technical talent."

CAPTION: Sen. Pete V. Domenici expresses concern about tests' reliability.

CAPTION: Sen. Jeff Bingaman wants effect of testing on science examined.