Overview

The Nevada National Security Site is a U.S. Department of Energy facility supporting nuclear security, stockpile stewardship, nonproliferation and national emergency-response missions. Its work includes experiments, remote testing, radiological training, environmental management and specialized infrastructure operations across a large federal site. Mission Support and Test Services operates the site for the National Nuclear Security Administration, which explains the employer and applicant context. The description keeps the public NNSS identity while clearly distinguishing the federal mission from its contracted operating company.