How the US Takes Care of Aging Nuclear Weapons

By: Madeline Butler ’24

It has been almost eight decades since a nuclear weapon has been fired in war, but these dangerous weapons still pose large threats as they age. Maintaining an aging nuclear arsenal is a difficult task, and the United States has ramped up investment in this maintenance.

“The U.S. will spend more than $750 billion over the next 10 years replacing almost every component of its nuclear defenses, including new stealth bombers, submarines and ground-based intercontinental ballistic missiles in the country’s most ambitious nuclear weapons effort since the Manhattan Project,” according to The Associated Press.

There are many different components of nuclear warheads that must be maintained. One of the most important parts is the core, which is a globe-shaped plutonium pit. These pits are made by engineers at the Energy Department’s lab in Los Alamos, New Mexico.

Many of the current pits in use come from the 1970s and 80s, which can be problematic because of plutonium’s aging process. Plutonium has a half life of 24,000 years, and while that suggests that the weapons should function properly for years to come, the plutonium decay is still enough to cause concern about how the pit explodes.

The United States has limited and outdated information on how plutonium degradation affects the weapons.

According to The Associated Press, “President George H.W. Bush signed an order in the 1990s banning underground nuclear tests, and the U.S. has not detonated pits to update data on their degradation since. When the last tests were performed, they provided data on pits that were at most about two decades old. That generation of pits is now pushing past 50.”

This lack of current data means that scientists can only make computer models to determine how well the aging plutonium pits might work instead of being able to perform real-world tests. This uncertainty has driven the United States to restart pit production.

Inside a highly classified building in Los Alamos, old plutonium is refurbished into new pits. The United States plans to fully recycle its first weapon-ready plutonium pit next year.

To protect and detonate the pits, an outer warhead layer is placed around the plutonium. These outer warhead layers are built at the Energy Department’s Kansas City National Security Campus.

The work necessary for restoring and testing warhead parts requires a great deal of precision, so workers need steady hands. To make sure those handling the parts meet this requirement, they must go through a skills assessment that includes disassembling and assembling a mechanical wristwatch.

“Everything is done under a microscope with tweezers,” said Molly Hadfield, a spokeswoman for the Kansas City plant. “And it’s pass (or) fail. Either the watch works, or it doesn’t work.”

The Kansas City plant is already busy with regular maintenance tasks like repairing the plastics, metal gear and wiring that have been weakened by years of exposure to radiation, but now they also must cope with the nuclear weapon maintenance overhaul.

The factory is also working on warheads for different delivery systems like stealth bombers and submarines.

“There’s a huge modernization effort going on,” said Eric Wollerman, who manages the Kansas City complex for the Department of Energy through its federal contract with Honeywell. “If you’re going to update the delivery systems, you would also then update the warheads in the missiles and the bombs that are with them.”

Nuclear weapons pose a great threat, both when used in warfare and as they sit idle. As our understanding of how to take care of the physical maintenance evolves, it is important to also evolve our understanding of how these weapons will or will not be part of our future.

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