NATIONAL LABS
Aging plutonium doesn鈥檛 鈥榗all into question鈥� performance of nuclear weapons, study finds
NNSA report comes after Santa Fe watchdog sued over Los Alamos plutonium pit data
A study made public this month by the National Nuclear Security Administration concluded that the U.S. stockpile of weapons-grade plutonium is aging but not at a rate that is affecting nuclear weapons鈥� performance.
In July, Nuclear Watch New Mexico, a Santa Fe nonprofit, sued the Trump administration for release of the study. Jay Coghlan, executive director of the group, said the government released an unclassified version of the study on Friday.
Coghlan argues the study undercuts a key claim used by the government to justify additional pit production: that the U.S. supply of weapons-grade plutonium is aging and thus needs replacement.
鈥淐rucially, no future pit production is to maintain the safety and reliability of the existing stockpile,鈥� Coghlan said in a statement this week. 鈥淚nstead, it is all for new-design nuclear weapons for the new arms race.鈥�
In a statement, the National Nuclear Security Administration said, 鈥淭he most recent JASON study confirms NNSA鈥檚 longstanding position that further scientific investigation is needed to understand plutonium aging.鈥�
鈥淕iven the importance of the nuclear stockpile to America鈥檚 national security, it would be irresponsible to delay the execution of NNSA鈥檚 two-site solution, as mandated by Congress,鈥� the statement said. 鈥淎fter the JASON report was received, it underwent an internal and interagency classification review process and was subsequently made available online.鈥�
JASON is an independent group of scientists 鈥� whose names are not disclosed 鈥� that has advised the government on defense matters since the 1960s.
Plutonium, a radioactive element, was first used for weapons production at Los Alamos National Laboratory in 1945. Scientists can only estimate how radioactive decay affects plutonium鈥檚 performance over decades.
According to the most recent JASON study, the current U.S. stockpile of plutonium pits is still useful to deploy in nuclear weapons.
鈥淭he (plutonium) in the stockpile appears to be aging slowly,鈥� the study, dated March 25, said. 鈥淭he degradation issues that have been observed do not call into question present weapons performance.鈥�
The study said that tests of the U.S. plutonium stockpile before 2010 showed no alarming signs of plutonium degradation. But after 2010, officials found 鈥渁ging effects鈥� in the plutonium stockpile. In response, the NNSA in 2021 created a 10-year research plan 鈥� which tested plutonium in national labs.
The JASON study called for further monitoring of the plutonium stockpile as it ages.
A separate 2023 said there are 3,748 warheads in the U.S. nuclear weapons stockpile, an 88% reduction since a Cold War peak in the 1960s. Most of the weapons in the current stockpile were built before 1992, when President George H.W. Bush signed a unilateral moratorium on underground nuclear testing passed by Congress.
The U.S. is also party to international treaties banning atmospheric, above-ground and underwater testing. As a result of such bans, the U.S. is unable to test its aging plutonium stockpile in weapons systems.
Justin Horwath covers tech and energy for the Journal. You can reach him at jhorwath@abqjournal.com.
