First Plutonium Pit For Nuclear Warhead Produced In The U.S. In 35 Years Is Now “Weapon-Ready”

The Department of Energy’s National Nuclear Security Administration (NNSA) has announced the completion of the first weapon-ready example of a vital component for the W87-1 warhead. The component, called a “plutonium pit,” is the radioactive component that acts as a first stage ‘trigger’ apparatus used to initiate the detonation of the thermonuclear device. Plans call for the W87-1s to be used in the future LGM-35A Sentinel nuclear-armed intercontinental ballistic missiles (ICBM), a program that is massively over budget and faces numerous issues.

The NNSA calls this “an important milestone for the United States’ nuclear weapon stockpile modernization” as it phases out the aging W78 warheads, one of two types that are placed atop LGM-30G Minuteman III ICBMs currently stationed in silos. The other is the W87-0.

“The W87-1 nuclear warhead will replace the W78 nuclear warhead, which was first introduced in 1979 and represents the oldest weapon in the U.S. nuclear stockpile that has not undergone a major life extension or replacement,” the Government Accountability Office noted. “The W87-1 will be carried on the Air Force’s Sentinel intercontinental ballistic missile and is slated for deployment in the early 2030s.”

The W87-0s will initially be installed on Sentinels, but those will eventually be phased out as well.

To make any of this happen, however, NNSA needs new plutonium pits. A good description of how the pits play a critical role in a nuclear warhead can be found at the Bulletin Of The Atomic Scientists, stating:

“Pits are the hollow plutonium cores of the fission “primaries” (triggers) of two-stage modern warheads. A warhead explosion would begin with the implosion of the pit to supercriticality, which would enable an exponentially growing fission chain reaction in the plutonium. That fission explosion—“boosted” by neutrons from a fusion reaction in tritium-deuterium gas injected into the middle of the hollow pit just before implosion—would ignite a much more powerful “secondary” nuclear fission-fusion explosion.”

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