Minuteman III ICBM operational test launch
An unarmed Minuteman III intercontinental ballistic missile launches from Vandenberg Air Force Base in February 2021. The Minuteman III is capable of carrying the Los Alamos–designed W78 warhead. U.S. Space Force/Chris Okula

Nuclear weapons are conceptualized, designed, developed, produced, maintained in the stockpile, and then retired and dismantled. This sequence is called the nuclear weapons life cycle and is detailed here.

Phase 1: concept study

The Department of Energy (DOE)/National Nuclear Security Administration (NNSA) and/or Department of Defense (DOD) make preliminary assessments of the effectiveness and survivability of a weapon concept and identify delivery system/nuclear warhead trade-offs.

Phase 2: program feasibility study

The technical feasibility of weapon concepts developed in Phase 1 is determined. Alternatives within the concepts are also developed.

Phase 2A: design definition and cost study

Once the feasibility study is completed, the Phase 2A study is conducted to refine warhead design definition, program schedule, and cost estimates.

Phase 3: full-scale engineering development

The program baseline is established. Additional efforts to test and evaluate the warhead to engineering standards are completed.

Phase 4: production engineering

DOE/NNSA transitions the developmental warhead design into manufacturing processes. The required production line equipment and tools are designed to ensure that all required components can be produced.

Phase 5: first production

DOE/NNSA procures raw materials, establishes the production line, starts producing components, evaluates the production processes and products, and makes modifications if necessary. DOE/NNSA conducts tests and evaluations of the warhead components from the production line.

Trident D5
An unarmed Trident II D5LE missile launches from the USS Maine in February 2020. These missiles can carry the Los Alamos–designedW76 or W88 nuclear warheads. Photo: U.S. Navy/Thomas Gooley

Phase 6: quantity production and stockpile maintenance and evaluation

DOE/NNSA increases the production rate of warheads and components and delivers the completed warheads to DOD for the stockpile. NNSA continues to test and evaluate components as required. Stockpile maintenance is performed. Safety, security, personnel reliability, use control, transportation, supply publications, accountability, inspections, emergency response preparation and exercises, and technical operations training are performed.

Phase 6.1: concept assessment

Concepts to meet DOD and DOE/NNSA needs are assessed. If valid, the Project Officers Groups (POG) decides whether a formal program study is warranted or whether the activity should be managed as a maintenance action outside the 6.X Process.

Phase 6.2: feasibility study and design options

The POG develops design options and assesses the feasibility (e.g., cost, schedule, and technical maturity) of these options based on developed criteria to include tradeoffs and courses of action depending on military characteristics, stockpile-to-target sequences, timelines, and budgetary and resource constraints to meet the needs for a particular nuclear weapon.

Phase 6.2A: design definition and cost study

The POG refines the down-select options by updating criteria, developing design and qualification plans, identifying production needs, and creating a preliminary life-cycle plan. This phase culminates with the release of the Joint Integrated Project Plan (JIPP) from the POG and the Weapon Design and Cost Report (WDCR) from the DOE/NNSA. The JIPP serves as the baseline control document for the stockpile sustainment activity.

Phase 6.3: development engineering

DOE/NNSA in coordination with the DOD conducts experiments, tests, and analyses to develop and validate the selected design option. The national laboratories initiate process development activities and produce test hardware, as required.

Phase 6.4: production engineering

DOE/NNSA refines the developmental design into a producible design and prepares the production agencies for production. DOE/NNSA updates production cost estimates and defines procedures with the DOD to conduct stockpile sustainment.

Phase 6.5: first production

DOE/NNSA production agencies produce the first warheads. The POG determines if these warheads meet design and military requirements.

Phase 6.6: full-scale production

DOE/NNSA must have written authorization from the NWC prior to beginning full-scale production and delivery of refurbished weapons for the stockpile.

Phase 7: retirement/storage

Retirement is the reduction quantity of that warhead-type in the stockpile. This phase initiates a process that continues until all warheads of that type are retired and dismantled.

Phase 7A: weapon retirement

Phase 7B: weapon dismantlement

Phase 7C: component and material disposal