NNSA Fully Redacts Vital Documents on Nuclear Weapon Cores

Below is a statement from Dr. Dylan Spaulding, a senior scientist in the Global Security Program at the Union of Concerned Scientists. Dr. Spaulding authored the 2025 UCS report on plutonium pit production.

The need to replace aging plutonium components in the stockpile is frequently cited by the NNSA to justify its multi-billion-dollar program to resume plutonium pit production- plutonium pits serve as the cores of modern thermonuclear weapons. In a 2025 report, UCS analyzed the available evidence on plutonium aging and concluded that the NNSA's efforts to resume plutonium pit production have not been technically justified on the basis of plutonium aging.

Congress mandated that the JASONs, an independent government advisory group, follow up on two previous analyses on the subject, both of which included unclassified summaries that were made publicly available. Despite being clearly marked as unclassified, the document released to UCS has been fully redacted by the NNSA.

"NNSA's choice to withhold what is clearly indicated as unclassified material calls into question whether the JASON's conclusions support NNSA's oft-stated urgency to resume and even accelerate pit production or whether scientific analyses that run counter to their program are being suppressed. If the study supports NNSA's efforts, one would think it is in their interest and in the public interest to release it.

"Earlier JASON studies have been highly influential in steering decision making and informing Congress about the technical needs of the national nuclear labs. This study comes at an especially crucial time as NNSA is asking Congress to fund plutonium pit production-possibly one of the most expensive efforts in the history of the nuclear weapons complex that, so far, lacks scientific justification."