I work for Sandia National Laboratories, until I retire at the end of this year. The National Laboratories don’t just guard weapons, they design and build them. Sandia is also involved with energy research (i.e. oil recovery and well logging), biomedical research (implantable sensors), nuclear proliferation, and special projects for the military not involving nuclear weapons (i. e. synthetic aperture radar for UAVs.)
This list is not exhaustive.