Overview

The National Nuclear Security Administration (NNSA) is an agency in the Department of Energy (DOE) that maintains and secures the US nuclear weapons stockpile.¹ It also works to prevent nuclear proliferation and terrorism, powers the US Navy through nuclear propulsion, and responds to nuclear and radiological emergencies domestically and abroad. NNSA executes its mission through a nationwide network of nuclear facilities—including test sites, production plants, and three national labs: Los Alamos, Lawrence Livermore, and Sandia. These sites house some of the world’s most powerful publicly available supercomputers, which serve as the computational backbone for NNSA’s AI research and nuclear simulations.

On AI, NNSA tests how frontier models might be misused to design or simulate nuclear or radiological weapons, develops safeguards to mitigate those risks, analyzes how AI systems affect nuclear proliferation, and applies AI to accelerate materials science, engineering design, and supercomputing that support the US nuclear deterrent.²

Background on NNSA

• Government context: NNSA is a semi-autonomous agency in the Department of Energy (DOE).³
• Mission: NNSA’s major missions focus on: 1) the US nuclear weapons stockpile, 2) nuclear nonproliferation, 3) counterterrorism and counterproliferation, and 4) powering the nuclear Navy.
• Main activities: Maintaining and modernizing the nuclear weapons stockpile through supercomputer-enabled simulation and life-extension programs⁴; securing and removing nuclear materials worldwide; providing nuclear propulsion for the Navy’s submarines and aircraft carriers; and operating emergency response teams for nuclear or radiological incidents at home and abroad.
• Budget: ~$24 billion (FY 2024)⁵
• Staff: ~2,000 federal employees and ~65,000 contractor employees (FY 2025)
• Brief history: Congress established the NNSA in 2000 to strengthen oversight for the US nuclear security enterprise after the Cold War.

Organizational structure

NNSA is led by the DOE Under Secretary for Nuclear Security, who also serves as the NNSA Administrator. 

The agency executes its mission through headquarters program offices and through a national network of nuclear facilities, including production plants, test sites, and its three national labs—Los Alamos, Livermore, and Sandia. 

NNSA’s major program offices are: 

• Office of Defense Programs: maintains and modernizes the US nuclear weapons stockpile; oversees NNSA’s national labs and production plants.
• Office of Defense Nuclear Nonproliferation: works to prevent the global spread of nuclear weapons, materials, and capability; supports international arms control and nonproliferation treaties.
• Office of Naval Reactors: joint DOE-Navy program managing design, deployment, and upkeep of naval nuclear propulsion systems.
• Office of Emergency Management: leads NNSA’s all-hazards emergency response and ensures continuity of operations during crises.
• Office of Counterterrorism and Counterproliferation: leads NNSA’s efforts to prevent, counter, and respond to nuclear terrorism and proliferation threats worldwide.
• Office of Defense Nuclear Security: secures all NNSA facilities, personnel, and information, through physical security, cybersecurity, and personnel protection programs. 

NNSA and AI policy

NNSA plays two growing roles at the intersection of AI and nuclear policy. First, it uses AI to advance its nuclear security mission, including by:

• funding and operating some of the world’s most powerful supercomputers, including El Capitan (ranked #1 in 2025), which provide the computational foundation for both AI research and nuclear simulations,
• simulating weapon physics and performance,
• optimizing engineering designs for warhead components,
• improving operational efficiency across laboratories and production facilities,
• enhancing nonproliferation efforts by detecting illicit nuclear activities through pattern recognition and anomaly detection, and
• expediting the nuclear weapons lifecycle, from materials discovery to manufacturing and surveillance. 

Second, following the 2024 National Security Memorandum on Advancing AI, NNSA leads federal efforts to test and evaluate frontier AI models to prevent their misuse in creating radiological or nuclear threats. The agency’s AI for Nuclear Deterrence (AI4ND) strategy guides this work, emphasizing the development of trusted and assured AI systems that are safe, reliable, and secure enough for high-consequence nuclear security environments. NNSA’s national labs put this strategy into practice, partnering with leading AI companies to build safety tools, fine-tune commercial models for classified research, and evaluate frontier systems.

Recent AI developments at NNSA

Major recent AI-related developments at NNSA

• October 2025: DOE’s AI strategy outlines how AI will advance NNSA’s national security missions, including deploying AI-enhanced physical security systems at national labs, streamlining regulatory processes for nuclear materials, and applying generative AI to accelerate engineering design for nuclear systems.
• August 2025: NNSA announces that its Venado supercomputer at Los Alamos is the first government computing system to run OpenAI reasoning models for national security applications.
• August 2025: Anthropic, in partnership with NNSA, unveils a classifier that distinguishes benign from concerning nuclear-related LLM conversations (reported ~96% accuracy in preliminary testing). 
• May 2025: NNSA leadership testify on AI integration plans before the Senate Armed Services Committee’s Strategic Forces Subcommittee. They described AI as “the next Manhattan Project” and outlined plans to apply AI “to every aspect of our nuclear deterrent mission,” including analyzing diagnostic data, optimizing experimental designs, and improving facility operations. They emphasize that AI will support the Stockpile Stewardship Program “with data those who created the program did not know was possible” and provide insights into adversaries’ military activities.
• October 2024: President Biden’s Memorandum on Advancing US leadership in AI directs DOE (through NNSA) to lead classified testing of frontier AI models for potential nuclear and radiological risks. 
• March 2024: NNSA’s Advanced Simulation and Computing (ASC) program publishes the AI for Nuclear Deterrence Strategy, outlining how AI will be deployed in NNSA’s high-security, high-consequence environment. 
• May 2023: Lawrence Livermore National Laboratory (an NNSA lab) announces a scaled-up collaboration with SambaNova to accelerate AI for science, building on 2020 DataScale integrations into the Corona supercomputing cluster.
• October 2020: NNSA partners with SambaNova Systems to expand AI computing at Lawrence Livermore and Los Alamos national labs, deploying DataScale systems to enhance high-performance simulations and machine learning capabilities.

NNSA components working on AI policy 

Several NNSA offices contribute to AI-related efforts, including (not comprehensive):

NNSA offices working on AI policy

• Office of Defense Programs: maintains and modernizes the US nuclear weapons stockpile; oversees NNSA’s national labs and production plants.
• NNSA National Labs (Los Alamos, Lawrence Livermore, Sandia): serve as core implementers of NNSA’s nuclear work, including its AI strategy.
  • AI Innovation Incubator (AI3): Based at Lawrence Livermore National Laboratory, AI³ coordinates research partnerships among national laboratories, federal agencies, and private AI developers. The program focuses on applying AI to scientific and engineering challenges across the nuclear security enterprise.
  • Center for Global Security Research (CGSR): Based at Lawrence Livermore National Laboratory, CGSR acts as a ‘think tank’ within the LLNL enterprise using open-source research to study deterrence dynamics, strategic stability etc…
• Office of Defense Nuclear Nonproliferation Research & Development (in DNN): leads AI-related applications in proliferation detection, data analytics, and international safeguards. It manages partnerships with national labs and academia on machine learning for nuclear forensics and threat analysis.
• Office of Counterterrorism and Counterproliferation (CTCP): coordinates AI safety testing and red-teaming for frontier models that could impact nuclear or radiological weapon design; investigates how AI could lower the barrier to access nuclear technical expertise.
  • Planning & Innovation (P&I): drives planning and technical solutions to address critical infrastructure security and resilience challenges; evaluates AI initiatives addressing critical infrastructure security concerns.

Working at NNSA

Full-time roles

NNSA’s workforce includes both federal staff and contractors:

• Federal careers: ~2,000 federal employees manage NNSA programs, develop policy, and oversee contracts. These roles are based primarily in Washington, DC; Germantown, Maryland; and Albuquerque, New Mexico.
• Contractor careers: ~65,000 contractor employees perform scientific, engineering, and production work to support NNSA’s mission.

Federal positions are posted on USAJOBS.gov; contractor positions require applying directly to specific labs or sites:

• Lawrence Livermore National Laboratory Careers
• Los Alamos National Laboratory Careers
• Sandia National Laboratories Careers
• Kansas City National Security Campus (managed by Honeywell FM&T)
• Savannah River Site (managed by Savannah River Nuclear Solutions)
• Nevada National Security Site (managed by Mission Support and Test Services)

Most NNSA positions require a security clearance and US citizenship. Applicants should expect to undergo a full background investigation to obtain a DOE “Q” clearance—equivalent to a Top Secret clearance in the Department of Defense.

Internships and fellowships

For internships, fellowships, and other early-career opportunities, check the Federal Internship Finder and the USAJOBS Federal Internship Portal, filtering for DOE positions. 

NNSA-specific programs include:

• NNSA Graduate Fellowship Program (NGFP): A one-year, salaried program that places recent graduate students (Master’s, PhD, or JD) in offices across the agency.
• Specialized Doctoral Fellowships: NNSA sponsors three fellowships for PhD students that provide 12-week minimum on-site DOE laboratory research experiences with a $45,000 annual stipend (renewable up to four years). Each focuses on a specific technical area:
  • Computational Science Graduate Fellowship (CSGF): applied computing for science and engineering 
  • Stewardship Science Graduate Fellowship (SSGF): materials under extreme conditions, nuclear science or high energy density physics
  • Laboratory Residency Graduate Fellowship (LRGF): engineering and applied sciences, physics, materials, or mathematics and computational science

Further reading

• The US Nuclear Security Enterprise: Background and Possible Issues for Congress, Congressional Research Service (2025)
• NNSA at a Glance, NNSA (2024)
• The DOE FY 2026 Budget in Brief, Office of the Chief Financial Officer (2025)
• AI for National Security, DOE

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