Albuquerque, N.M. ? The Los Alamos National Laboratory director, tired of security lapses at the northern New Mexico lab, has brought nearly all work there to a standstill and is calling scofflaw “cowboys” out for a final showdown.

Pete Nanos took the unprecedented step Friday of broadening a stand-down of classified work to include all lab activities.

“We are doing this as part of an effort to ensure this laboratory operates safely and meets our national security obligations,” Nanos said in a memo to all employees.

He said there would be exceptions to his order, so that critical missions and essential national security functions continue unabated.

Nanos made the announcement a day after the University of California, which manages the lab for the Department of Energy, ordered him to halt classified work at the lab. The action followed a security lapse last week in which two electronic data storage devices turned up missing.

Nanos blamed “cowboys” who are disobeying rules on the handling of sensitive material. “I don’t care how many people I have to fire to make it stop,” he said.

“If you think the rules are silly, if you think compliance is a joke, please resign now and save me the trouble,” he said.

The lab’s most recent embarrassment occurred Wednesday, when an intern at the lab suffered a serious eye injury while working on an experiment involving a laser.

Researchers thought the laser wasn’t producing a light when it entered the 20-year-old intern’s eye, causing a retinal lesion, said lab spokesman Jim Fallin. The intern was to be flown to Baltimore to see a specialist.

“She’s in good spirits,” Fallin said of the intern. “I’m told that while this injury is considered serious, it’s not expected that she’ll lose vision in her eye.”

Nanos told employees that the labwide stand-down isn’t due to a lack of confidence in them, but rather an opportunity to reflect on their responsibilities and make sure they can do their jobs safely and securely.

While lab spokesman Kevin Roark acknowledged Friday’s decision was extreme, he said: “We know here at the lab that it’s the right thing to do.”