The 1604 design was used by the Soviet nuclear weapons laboratory.
Since then, weapons laboratories and other federal agencies have worked hard on the problem.
Clearly, he has not done enough to solve security problems at the nuclear weapons laboratories.
But other experts at the nation's weapons laboratories are challenging this view.
Nuclear weapon laboratories are working to perfect the electric car.
This should have set off alarm bells at the national weapons laboratories.
The weapons laboratories' security practices have been criticized by outside investigators for years.
The witnesses before the panel included officials from American nuclear weapons laboratories, one witness said.
He said his men had stopped more than 15 suicide bombers and uncovered five weapons laboratories.
But today, officials at the weapons laboratory say the category has long been troublesome, given its ambiguous nature.