National Nuclear Security Administration | Department of Energy Official websites use .gov .gov website belongs to an official government organization in the United States. Secure .gov websites use HTTPS lock ) or means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. National Nuclear Security Administration Missions The U.S. Nuclear Weapons Stockpile One of NNSA’s core missions is to ensure the United States maintains a safe, secure, and reliable nuclear stockpile through the application of unparalleled science, technology, engineering, and manufacturing. The Office of Defense Programs carries out NNSA’s mission to maintain and modernize the nuclear stockpile through the Stockpile Stewardship and Management Program. Nonproliferation NNSA works to secure or dispose of dangerous nuclear material, and detect and control the proliferation of related WMD technology and expertise. about Nonproliferation October 1, 2025 Powering the Navy The Naval Nuclear Propulsion Program provides militarily effective nuclear propulsion plants and ensures their safe, reliable and long-lived operation about Powering the Navy March 5, 2026 Counterterrorism and Counterproliferation NNSA has a key role in U.S. efforts to prepare for, prevent, and respond to a terrorist or other non-state actor with a nuclear or radiological device about Counterterrorism and Counterproliferation July 28, 2025 Established by Congress in 2000, NNSA is a semi-autonomous agency within the U.S. Department of Energy that protects our nation by designing and delivering a safe, secure, reliable, and effective U.S. nuclear stockpile; forging solutions that enable global security and stability through nonproliferation, counterproliferation, and emergency response; providing nuclear propulsion to power a global U.S. Navy; and leveraging transformative technologies to address emerging challenges. NNSA and our partners across laboratories, plants, and sites — collectively the Nuclear Security Enterprise — provide comprehensive nuclear security solutions that protect the American people, our allies, and our partners in a dynamic world. About NNSA Leadership Locations Budget Careers Documents Fact Sheets Remarks Videos Latest News Nonproliferation Nuclear Security & Safety NNSA Helps Armenia Become Free of Highly Radioactive Material April 15, 2026 Modernize America’s Nuclear Stockpile Nuclear Security & Safety NNSA and Lawrence Livermore National Laboratory Advance Laser Upgrade for Nuclear Stockpile Mission Ahead of Schedule April 13, 2026 Nuclear Security & Safety NNSA issues Notice of Availability for the Draft Programmatic Environmental Impact Statement for its plutonium pit production mission April 10, 2026 Nonproliferation Nuclear Security & Safety NNSA Removes High-Risk Cesium from South Carolina, Enhancing National Security April 9, 2026 View All News Web Articles Nonproliferation Nuclear Security & Safety NNSA transitions American-made molybdenum-99 effort to DOE Office of Energy Dominance Financing April 9, 2026 Nonproliferation Nuclear Security & Safety NNSA and Texas A&M work together to strengthen U.S. environmental security March 20, 2026 Nuclear Security & Safety Nonproliferation Making America safer: NNSA removed 68 radioactive devices in 2025, strengthening U.S. radiological security February 4, 2026 Nuclear Security & Safety Bridging NNSA with Congress and communities January 29, 2026 View all Web Articles Offices Congressional and Intergovernmental Affairs March 18, 2026 Counterterrorism and Counterproliferation July 28, 2025 Defense Nuclear Security March 25, 2026 Emergency Management March 5, 2026 General Counsel November 25, 2024 Infrastructure March 5, 2026 Nonproliferation October 1, 2025 Nuclear Security & Safety Nuclear Stockpile The U.S. Nuclear Weapons Stockpile March 5, 2026 Partnership and Acquisition Services March 5, 2026 Powering the Navy March 5, 2026 Supporting NNSA's missions January 29, 2026 Working at NNSA March 5, 2026 Social Media