[en] While spent nuclear fuel no longer sustains nuclear chain reactions that can generate electricity, it still contains nuclear material for potential use in weapons. This is why the verification of spent fuel is a central component of the IAEA’s nuclear safeguards work. Spent fuel is typically stored under water for cooling. Verifying spent nuclear fuel under water can be a tricky and lengthy process. It requires IAEA inspectors to position themselves above the spent nuclear fuel pools to take pictures of individual spent fuel assemblies, of which there can be hundreds at a time. This process was identified as an area where robotics has the potential to play a useful role, and, in 2017, the IAEA launched a challenge to crowdsource ideas and seek solutions to make spent fuel verification more effective and efficient. When performing their inspection activities at nuclear facilities around the world, nuclear safeguards inspectors frequently use a small hand-held optical instrument called the improved Cerenkov viewing device (ICVD). The ICVD confirms the presence of spent nuclear fuel stored under water, where it is typically placed for cooling following its removal from the reactor core. Inspectors are tasked with verifying whether the amount of fuel stored matches the amount declared by national authorities, and that none of it has been removed and potentially diverted from peaceful use.