Clampdown At Los Alamos

A search is under way for computer disks containing atomic weapons secrets missing from the nuclear weapons lab at the Los Alamos National Laboratory in New Mexico.

In an unprecedented action, classified work on America's nuclear weapons has been shut down at Los Alamos until the two missing computer discs have been found. Twenty nuclear scientists had their top secret clearances suspended and must now go to work under escort.

As CBS News Correspondent Wyatt Andrews reports, this is no error in paperwork. The lab director admits this time someone removed some of the nation's important nuclear secrets on purpose.

"Because of the fact that we now have people who knew the rules and decided not to follow them, that enters a level of risk that we haven't had to face before," says Pete Nanos, Director of Los Alamos National Laboratory

Sources tell CBS News Los Alamos is missing two high capacity storage discs from the top-secret area called the weapons physics directorate.

"The place in Los Alamos that's actually lost these materials is the place that is actually working on the design of nuclear weapons and testing the current nuclear weapons," says Danielle Brian, executive director of Project On Government Oversight, a government watchdog group. "I mean you really can't get more sensitive than that."

And this is just the latest Los Alamos embarrassment.

The lab has now lost secret computer discs three times in the last eight months. CBS News has also reported on misplaced hard drives that were later found behind a copier and credit card mismanagement and theft charges totaling $100 million.

Some officials believe part of the problem comes from scientists too wrapped in their work to pay attention to security. But outside critics charge enough is enough.

"Who knows what other kinds of breeches that are taking place, because there is just such a general lack of concern about this level of security," says Brian.

Still, the real question is what happened to the secrets? Experts say the best case is that someone took the discs home and is afraid to admit it. Worst case is a sale to an enemy.