As announced by the U.S. Department of Energy's National Nuclear Security Administration (NNSA), the First Production Unit (FPU) of a plutonium pit for the W87-1 Modification Program at Los Alamos National Laboratory (LANL) was verified as complete on Oct. 1.
This first fully qualified plutonium pit for the W87-1 nuclear warhead was "diamond stamped" after meeting all requirements, signifying its readiness for deployment to the U.S. nuclear stockpile at "war reserve" quality. A plutonium pit is a necessary component in America's nuclear warheads which initiates the nuclear reactions when compressed by high explosives.
Achieving FPU of the W87-1 pit is an important milestone for the United States' nuclear weapon stockpile modernization. The W87-1 warhead supports the Department of Defense's Sentinel Intercontinental Ballistic Missile (ICBM), which will be part of the land-based leg of the nation's nuclear deterrent and replaces the Minuteman III ICBMs.
While production was completed at Los Alamos, Lawrence Livermore National Laboratory (LLNL) has been responsible for the design of the W87-1 plutonium pit and led the product realization team - a collaborative working group comprised of the design and production agencies which evaluates whether component designs meet requirements through testing and assessments and works to improve manufacturability and minimize production risks.
"Meeting this critical milestone in collaboration with NNSA is the culmination of more than a decade of work at LLNL and across the enterprise," said Brad Wallin, deputy director for Strategic Deterrence. "Numerous teams have all pulled together to play essential roles, identifying transformational process efficiencies along the way. Their collective diligence and unyielding commitment to the national mission are remarkable."
LLNL has worked closely with experts from across the enterprise, including Kansas City National Security Campus, responsible for production of non-nuclear components, and Los Alamos, where the plutonium pits were manufactured, and overall assembly of the pits was completed. The agencies worked in close collaboration with NNSA for more than eight years to develop and mature qualification, certification, and product acceptance processes required to manufacture this FPU pit.
Additionally, experimental capabilities at Livermore and other sites contributed to assessment and certification of the W87-1 pit. An array of capabilities at the Superblock's Plutonium Facility were used to prepare samples and perform qualification tests on pit coupon samples. The JASPER two-stage gas gun at the Nevada National Security Site played a central role in LLNL designers' evaluation of plutonium under extreme conditions. In addition, LLNL designers conducted a series of hydrodynamic experiments that integrated relevant materials in warhead configurations. These integrated tests - performed at the Laboratory's Site 300 Experimental Test Site and at LANL research facilities, including the Dual-Axis Radiographic Hydrodynamic Test Facility - were completed without plutonium, and helped guided pit design to meet military requirements.
Plutonium is a man-made element that was discovered in 1940. Today, researchers know more about plutonium aging and decay, and how the changing properties of a plutonium pit could affect the performance of a nuclear weapon. Resilient, enduring plutonium pit production is needed to replace aging pits and to meet evolving Department of Defense requirements, both of which are vital to maintaining an effective and credible nuclear deterrent. The U.S. recycles plutonium from old pits to make new ones. Learn more about the plutonium pit production mission at LANL's Plutonium Facility, known as PF-4, to advance stockpile modernization and fulfill the deterrence requirements of the Department of Defense.
