 | |
| Agency overview | |
|---|---|
| Formed | 2000[1] |
| Headquarters | James V. Forrestal Building 1000Independence AvenueSW Washington, D.C., U.S. |
| Employees | 2,600+ federal (2024), 65,000 contract (2024) |
| Annual budget | $22.2 billion (FY24) |
| Agency executive |
|
| Parent agency | Department of Energy |
| Key document | |
| Website | www |
TheNational Nuclear Security Administration (NNSA) is a United States federal agency responsible for safeguarding national security through the military application ofnuclear science. NNSA maintains and enhances thesafety, security, and effectiveness of the U.S.nuclear weapons stockpile; works toreduce the global danger fromweapons of mass destruction; provides theUnited States Navy with safe and effectivenuclear propulsion; and responds to nuclear and radiological emergencies in the United States and abroad.[2]
Established by theUnited States Congress in 2000, NNSA is a semiautonomous agency within theUnited States Department of Energy.
NNSA was created by congressional action in 1999,[3] in the wake of theWen Ho Lee spy scandal[4][5] and allegations that direct management by the Department of Energy had resulted in U.S. nuclear secrets being leaked to China.[6] Originally proposed to be independent, it was instead chartered as a semiautonomous agency within the Department of Energy to be headed by an administrator reporting to the secretary of energy.[7] The firstunder secretary for nuclear security and NNSA administrator appointed wasAir Force General (and CIA deputy director)John A. Gordon.[8]
In 2006, NNSA's administrator took responsibility when employee information was hacked.[9]
In February 2025, CNN reported that theTrump administration had fired 300 NNSA employees, while the Department of Energy responded that "less than 50 people" had been fired, and that the fired employees "held primarily administrative and clerical roles".[10] The next day, the Trump administration informed NNSA that "termination letters for some NNSA probationary employees are being rescinded, but we do not have a good way to get in touch with those personnel", since the fired employees had been blocked from their federal government email accounts, so the Trump administration asked NNSA to forward the notice to the fired employees' personal email accounts.[11]
In July 2025, some NNSA systems were reported to have been breached byChinese state-sponsored advanced persistent threat groups dubbed Linen Typhoon, Violet Typhoon and Storm-2603.[12]
NNSA has the following missions with regard to national security:[13]
One of NNSA's primary missions is to maintain the safety, security and effectiveness of the United States' nuclear weapons stockpile.[14] After theCold War, the U.S. voluntarily endedunderground nuclear testing. NNSA maintains the existingnuclear deterrent through the use of science experiments, engineering audits and high-tech simulations at its threenational laboratories:Los Alamos National Laboratory,Lawrence Livermore National Laboratory, andSandia National Laboratories. It also creates new weapons programs as required by theUnited States Department of Defense.[15]
NNSA assets used to maintain and ensure the effectiveness of the American nuclear weapons stockpile include theDual-Axis Radiographic Hydrodynamic Test Facility (DARHT) at Los Alamos National Laboratory, the Contained Firing Facility at Lawrence Livermore National Laboratory and theZ Machine at Sandia National Laboratories.[16][17][18] NNSA also uses powerfulsupercomputers to run simulations and validate experimental data; these computers often appear on theTop500 list. In fact, LLNL'sEl Capitan is the fastest supercomputer in the world.
Another important asset used to test the stockpile is theNational Ignition Facility (NIF) atLLNL, a laser-based inertial confinement fusion research device.[19] NIF achieved the first scientific breakeven controlled fusion experiment on December 5, 2022, with an energy gain factor of 1.5.[20] Since then, the feat has been accomplished many more times.[21]
TheOffice of Secure Transportation provides safe and secure transportation of nuclear weapons and components and special nuclear materials, and conducts other missions supporting national security.[22] OST shipments are moved in specially designed equipment and escorted by armed and specially trainedfederal agents.[23]
NNSA's Office of Defense Nuclear Nonproliferation works with international partners, federal agencies, U.S. national laboratories, and the private sector to discover, protect, and or dispose of radiological and nuclear materials.[24]
The office strives to:[24]
The agency created theGlobal Threat Reduction Initiative in 2004 to expand efforts similar to theCooperative Threat Reduction program beyond the former Soviet Union.[25][26]
In 2016, GTRI was renamed the Office of Materials Management and Minimization, and continues the efforts of supporting reactor conversions, fuel returns, and LEU fuel development.
The work of the Office of Materials Management and Minimization is divided into three subprograms: Conversion, Nuclear Materials Removal, and Material Disposition.
Through this office and its predecessors, NNSA has successfully led the recovery efforts of nuclear materials from dozens of countries. Since 1996, the Department of Energy/NNSA has disposed of enough material to produce more than 325 nuclear weapons.[27]
For example, in 2017, it removed all the highly enriched uranium from Ghana and repatriated it to China. The Ghanaian reactor now uses low-enriched uranium.[28]
NNSA's Office of Counterterrorism and Counterproliferation focuses on:[29][30]
The office oversees the capabilities of theNuclear Emergency Support Team.
NNSA deploys response teams dozens of times each year, usually to check for radioactive materials. Missions assuage safety concerns, support other agencies, and bolster law enforcement capabilities at large public events such as presidential inaugurations and the Super Bowl.
NNSA provides expertise, tools and technically informed policy recommendations to advance U.S. nuclear counterterrorism and counterproliferation objectives. It is responsible for understanding nuclear threat devices and foreign activities that cause proliferation concerns. To do this, members of the counterproliferation office confer with international counterparts on nuclear security and counterterrorism; conduct scientific research to characterize, detect and defeat nuclear threat devices; develop and conduct WMD counterterrorism exercises; and promote nuclearinformation security policy and practices.
NNSA'sNuclear Propulsion Program – working with Naval Nuclear Laboratories – is responsible for providing efficient nuclear propulsion plants to the United States Navy. It is also known asNaval Reactors. It conducts the design, development and operational support required to power all the U.S. Navy'saircraft carriers andnuclear submarines. The program consists of both civilian and military personnel who maintain, design, build, and manage the reactors.
The following are the elements of the program:[31]
NNSA has several offices that support its primary missions. Among them are:
NNSA's Office of Emergency Operations has the obligation of responding to emergencies on behalf of the entire Department of Energy.[32] Its high level of alertness allows the United States to respond to incidents in a rapid manner.
NNSA's Office of Defense Nuclear Security is responsible for the overall security of facilities housing nuclear weapons as well as the components and materials required to develop them -- this includes oversight ofFederal Protective Forces -- contractors who safeguard NNSA's labs, plants, and sites.[33] The office also safeguards personnel and produces threat assessments.[33]
| Deputy Secretary of Energy |  | |
|---|---|---|
| Under Secretary of Energy for Infrastructure | Office of Cybersecurity, Energy Security, & Energy Response | |
| Under Secretary of Energy for Nuclear Security | ||
| Under Secretary of Energy for Science and Innovation | ||
| Assistant Secretary of Energy for Nuclear Energy | ||
| Power Marketing Administration | ||
| National Laboratory System | ||
| Energy Department Facilities and Reservations | ||
| Related Independent Agency | ||
| International | |
|---|---|
| National | |
| Other | |