Cumulative cost and schedule overruns have increased since 2023 for the National Nuclear Security Administration’s (NNSA) portfolio of major projects in the execution phase, according to a report by the Government Accountability Office (GAO).
As of June 2025, the NNSA’s portfolio’s cumulative cost overrun has increased from $2.1 billion in 2023 to $4.8 billion, the February report said. The cumulative schedule delay increased from nine years in 2023 to 30 years in 2025.
NNSA has 16 major projects in the execution phase, meaning the cost and schedule baselines have been approved, according to the report. Two of the 16, the Uranium Processing Facility’s Main Processing Building and Salvage and Accountability Building at the Y-12 National Security Complex, have struggled most
Seven other major projects either have or are expected to incur a cost overrun of over 20% from the original baseline, GAO said. The overruns and delays were mainly associated with “inadequate project management” by NNSA contractors. This includes “poor performance” of the primes’ subcontractors or vendors, or increased cost of equipment, materials or vendors, GAO said.
“In prior work, GAO made multiple recommendations to improve NNSA’s management of its major projects,” the report said. It added that while NNSA agreed with most of the recommendations and implemented “many changes,” as of December 2025 “NNSA had not fully addressed eight of the 21 recommendations.”