"In March 2009, the National Nuclear Security Administration (NNSA), a separately organized agency within the Department of Energy, completed construction of the National Ignition Facility (NIF). NNSA considers NIF critical to its stockpile stewardship program to ensure the safety and reliability of the nation's nuclear weapons, absent live nuclear testing. NIF is intended to simulate the extreme temperatures and pressures of "ignition"-an atomic fusion event propagating a nuclear explosion-for the first time in a laboratory. GAO was asked to examine (1) the extent to which NNSA has addressed key scientific and technical challenges that could prevent ignition at NIF; (2) whether NNSA has an effective approach for managing the cost, schedule, and scope of ignition-related activities; and (3) potential impacts to NNSA's stockpile stewardship program if ignition at NIF is not achieved, as planned, between fiscal years 2010 and 2012. To conduct this work, GAO analyzed relevant budgets, reports, and plans, and interviewed NNSA and national laboratory officials and independent experts.