Results of the BeCamp2 Measurement Campaign

Within the framework of the activities of Phase III of the International Partnership for Nuclear Disarmament Verification (IPNDV) and based on the lessons learned from the 2019 Belgian measurement campaign, the Belgian Nuclear Research Centre SCK CEN proposed a new measurement campaign, called BeCamp2.
The measurement campaign was held September 11–29, 2023, with 10 measurement teams participating.
Each team deployed one or more measurement technologies to verify their capabilities in the framework of their potential use in nuclear disarmament verification activities.
The goal of the measurement campaign was to carry out measurements on unknown items containing different radioactive sources (including 235U and Pu) and various shielding materials.
The results of the measurements were used to answer a questionnaire containing typical questions identified in IPNDV discussions, such as verifying the absence of special nuclear material and confirming whether an item is of the same class as a reference item.
In addition, the participants were offered the possibility to carry out neutron active interrogation with a moderated neutron source.
We report about the content of the measurement campaign, describing first the available items and types of measurements that were carried out.
We then focus on the disarmament questions that each team tried to answer.
The questionnaire results are discussed for each item and in an aggregated form; in the discussion of the results, we examine what answers can be interpreted to be correct as well as possible limitations in the answers, given a set of available technologies.
We also discuss the chosen approach to report the experimental and data analysis results.
We conclude with the lessons learned and outlook on future activities.