National Nuclear Security Administration: Agency Should Improve Cost Growth Notification Process

What GAO Found

Over the next 2 decades, the United States plans to spend tens of billions of dollars to modernize its nuclear weapons stockpile and the research and production infrastructure on which its stockpile programs depend. The National Nuclear Security Administration (NNSA) is responsible for managing these efforts.

Since 2011, NNSA has been required by law to report on cost baselines and cost growth for certain construction projects and nuclear weapons acquisition programs. For example, NNSA must notify congressional defense committees when construction projects initially set cost baselines that exceed $65 million, and again if costs are expected to exceed baselines by 25 percent or more. Within 90 days of submitting a cost growth notification, NNSA must also provide additional information, including an assessment of the root causes of the cost growth.

However, NNSA has not implemented effective processes to manage such notifications for construction projects, which has led to delays in notifications. GAO identified 14 NNSA construction projects that established a cost baseline that met the reporting criteria. All 14 provided notification of an initial baseline and seven are experiencing reportable cost growth. However, NNSA has not provided notifications in five of the seven instances. NNSA officials said that notifications were being prepared for some of the projects but has not provided them to congressional defense committees.

Officials also acknowledged that NNSA had not sent root cause assessments in most cases. The two assessments that NNSA provided did not address legally required elements, such as the extent to which unrealistic performance expectations or immature technologies played a role in cost growth.

Table: Status of Cost Growth Notifications for Ongoing National Nuclear Security Administration (NNSA) Projects Costing over $65 Million, as of April 2025

Source: GAO analysis of Department of Energy project reporting data and NNSA documentation. | GAO-25-107767

^aIn 2022, one project provided a cost growth notification, as well as notifications of recertification, a new baseline cost, and an assessment of root causes. However, it subsequently experienced additional reportable cost growth and established a new baseline in May 2025, but has not provided the additional notifications to date, which is not reflected in these figures.

NNSA is also required to report on cost baselines for programs to acquire new nuclear weapons or life extension programs, and for programs to alter existing weapons where costs exceed $800 million. For three such programs that met the baseline reporting requirement, NNSA has used an existing reporting requirement to communicate initial cost and schedule baselines rather than provide separate notifications. At the time of GAO’s review, none of the three programs met the criteria for cost growth reporting in effect at the time—a total cost increase of at least 25 percent or a per unit increase of at least 50 percent.

NNSA officials responsible for cost growth reporting told GAO that they planned to implement new processes with an initial focus on the process for construction projects, including the use of templates and root cause assessment guidance. However, officials said they were in the early stages and could not provide a timeline for completion. If implemented effectively, templates, guidance, and processes could help NNSA ensure it is providing accurate and timely information to congressional decision-makers

Why GAO Did This Study

House Report 118-529 includes a provision for us to review NNSA’s cost growth notification processes. GAO’s report assesses NNSA’s implementation of this provision and opportunities NNSA has identified to improve its cost growth notification requirements.

GAO reviewed and analyzed provisions of law that relate to cost controls and reporting, NNSA directives and guidance, and NNSA documentation related to cost monitoring and notifications for construction projects and weapons programs. GAO also interviewed officials with NNSA and the Office of Management and Budget.