NNSA’s Counterterrorism and Counterproliferation (CTCP) Office led the U.S. delegation at the Nuclear Forensics User Group (NFUG) Annual Plenary, hosted by the United Kingdom’s Ministry of Defence in September.
National Nuclear Security Administration
December 15, 2025
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From September 23-25, NNSA’s Counterterrorism and Counterproliferation (CTCP) Office led the U.S. delegation at the Nuclear Forensics User Group (NFUG) Annual Plenary, hosted by the United Kingdom’s Ministry of Defence
NFUG is a longstanding collaboration between U.S. national laboratory scientists, members of the federal interagency, from the Department of War, the Department of Energy, the Department of State, and their UK counterparts. NFUG seeks to prevent and deter illicit nuclear materials or weapons use by leveraging the nuclear forensics expertise of both nations. Nuclear forensics is the technical ability to uncover the source of interdicted nuclear materials, nuclear devices, or unattributed nuclear events, helping hold nuclear traffickers and state sponsors of terrorism accountable.
While NFUG collaborations started with scientific exchanges that helped both nations expand their knowledge base and compare technical processes, NFUG’s current initiatives further develop operational capabilities for real-world events, to include increasing engagement with the intelligence and law enforcement communities. Looking to the future, the United States and United Kingdom aim to make their processes and capabilities increasingly interoperable thereby reducing response times from a nuclear event to being able to provide valuable technical information and reach a shared conclusion to senior leaders no matter where an incident occurs.
Alison Goodsell, the U.S. NFUG Co-Chair and director of CTCP’s Office of Nuclear Forensics, emphasized the importance of U.S.-UK collaboration, telling the Plenary that “by pursuing comparable forensic analytic techniques, U.S. and UK experts provide senior decisionmakers with scientific and credible information to underpin joint statements attributing any malicious use of nuclear material and pave the way for a unified response.”
During the NFUG Plenary scientists from the U.S. National Laboratories gave joint presentations with their UK colleagues on a wide range of topics, highlighting advances made in the previous year and initiatives for the coming year. Topics spanned the nuclear forensics mission space, including: nuclear materials analysis; conventional forensics on components of an improvised nuclear device; and device assessment for a post-detonation response.
A key theme of these presentations was the exercises that validate and test the capabilities of both nations. Steven Laws, the UK Ministry of Defence’s Co-Chair for NFUG said that “this is a truly collaborative exchange, both nations working towards a common goal. These teams are at the leading edge of science applied to nuclear forensics and the exercises and peer reviews provide high confidence in the readiness of both nations to counter the threat of nuclear terrorism”.
With the Plenary concluded, NFUG participants have returned to their respective National Labs and offices, integrating the valuable insights gained and charting the course for continued collaborative advancements. The momentum from this year's discussions will propel another year of dedicated work supporting United States, United Kingdom, and global security. Planning is already well underway for next year’s Plenary, set to be hosted in the United States, underscoring the commitment of the United States and United Kingdom to strengthen this unique partnership to deter and counter some of the most dangerous threats to our nations.