Ms. Lockhart currently serves as the Acting Deputy Associate Administrator (SES) for the National Nuclear Security Administration (NNSA) Office of Counterterrorism and Counterproliferation (CTCP).  In this position, Ms. Lockhart is responsible for overseeing and advancing programs that counter nuclear terrorism and nuclear proliferation.  CTCP organization also manages capabilities to prepare for and respond to nuclear and radiological accidents and incidents worldwide.

Prior to her detail with CTCP, Ms. Lockhart served as the Assistant Deputy Administrator for Strategic Materials Production Modernization within the Office of Defense Programs.  In this role she managed strategic investments to modernize the Nation's capabilities to produce tritium gas, new sources of enriched uranium, and components for the secondary stage of nuclear explosive packages for the weapons stockpile.

Before serving as the Assistant Deputy Administrator for Strategic Materials Production Modernization, Brittany held several roles within NNSA’s Office of Defense Programs focused on production modernization and strategic materials sustainment for the nuclear weapons stockpile.  She has led several high-visibility efforts to build and execute multi-billion-dollar nuclear modernization programs with significant risks and aggressive delivery dates, ensuring NNSA delivered capabilities on time to meet weapons requirements for the Department of War. 

Ms. Lockhart was a project leader at the Defense Nuclear Facilities Safety Board where she led technical and safety reviews of the Department’s design and construction projects to provide independent safety analysis, advice, and recommendations to the Secretary of Energy.  She holds degrees in Chemical Engineering from the University of Virginia and the University of Maine.