LLNL works to ensure the nation's remaining nuclear deterrent remains safe, secure, and reliable as part of the Department of Energy's Stockpile Stewardship Program . This ongoing effort requires a science-based fundamental understanding of nuclear weapons performance — from developing enhanced warhead surveillance tools that detect the onset of problems to manufacturing capabilities that produce critical components. PLS researchers work with scientists and engineers from across the Laboratory to support projects associated with Nuclear Security and Stockpile Stewardship.