There are around 150 incidents of unauthorised activities involving nuclear and radioactive materials reported each year, including smuggling and theft. Why is this a grave issue of concern? How do we find those responsible? And who’s job is it to stop these materials going outside of regulatory control? David Smith, Visiting Research Fellow at King’s College London and an expert in nuclear forensics, answers these questions. He gives us an insight into the life of a nuclear forensic scientist and touches on some of the biggest nuclear security challenges in recent years, such as how the war in Ukraine has impacted the safety of nuclear facilities and undermined the policing of nuclear trafficking in the region, the impact of Covid 19 on nuclear security protocols, and the risks posed by climate change.