A new U.S. Government Accountability Office assessment of construction projects managed by the National Nuclear Security Administration finds that cost overruns and schedule delays across several defense nuclear modernization facilities have more than doubled since 2023. The Feb. 27 report updates GAO oversight of agency construction projects and compares current performance with a 2023 review of its nuclear weapons infrastructure modernization program. GAO found cumulative cost growth on key agency construction efforts rose from about $2.1 billion in 2023 to roughly $4.8 billion as of June 2025. Read More GAO | Nuclear Security Enterprise Assessment The agency’s capital program includes new and replacement facilities supporting uranium processing and plutonium pit manufacturing. It manages 28 major construction projects valued at more than $100 million each, representing a portfolio worth at least $30 billion, said GAO. Sixteen are under construction, with 12 in design or early planning.…