Deployment of the First Photofission Measurement System Dedicated to SNM Detection in Europe: Outcomes and Future Prospects

Special Nuclear Material (SNM) such as uranium and plutonium isotopes could be potentially used to make a nuclear bomb involved in a terrorist attack. To prevent illicit trafficking of SNM in Europe, inspection of cargo containers at borders is required. X-ray scanning is widely used by customs to control suspect containers. However, this technology is not the most adapted to bring to light SNM signature. Therefore, a second line technology based on the photofission reaction could enable to detect SNM in a non-destructive manner. In the frame of the C-BORD European project, several teams specialized in photofission have joined forces to design an active photon interrogation system enabling to detect SNM hidden in cargo containers. The system is based on the use of a linear electron accelerator (linac). First, high-energy photons generated by Bremsstrahlung in the conversion target of the linac irradiate a suspect area of the cargo container. Secondly, prompt and delayed particles emitted following photofission reactions are detected if SNM is present. The largest seaport in Europe (Maasvlakte, in the suburbs of Rotterdam, Netherlands), where 9 MeV linacs are used by Dutch customs for X-ray scanning, has been chosen as test site. In order to deploy a full system taking advantage of all photofission signatures, different subsystems have been developed. In this paper, first, we give an overview of the photofission system. Then, we show how the system has been deployed at the Rotterdam seaport in September and October 2018 and tested on mock-ups of cargo containers. Finally, we show that setting up a photon interrogation system on an industrial facility initially designed for X-ray scanning is a challenge which has been successfully met in the frame of the C-BORD project to deploy the first photofission measurement system on an industrial site in Europe. The outcomes of this first deployment will be exposed and the future challenges to be addressed will be discussed.