January 4, 2021 In the last week of November 2020, NPL hosted its Conference on Applied Radiation Metrology (CARM), which was run virtually as a series of Microsoft Teams sessions. The conference was the latest in a series by NPL for the nuclear metrology community. The conference included over 80 presentations from 15 countries across 16 sessions. In total, 526 people attended the conference from 347 cities and 61 countries (Figure 1). CARM included a well-attended session on Nuclear Decommissioning Metrology as well as Advances in Nuclear Data, Carbon-14 Metrology, High Energy Neutron Fields, Nuclear Medicine, Reference Material and Proficiency Test Exercise Development and Applications for Decommissioning, Environmental Monitoring and Forensics. There was a joint workshop with UKAEA to address measurement challenges around fusion, and a session was hosted by BIPM on International Metrology challenges attended by participants from 15 countries. The Nuclear Decommissioning session included a presentation on the main outcomes of MetroDECOM2 presented by the project coordinator Dr Peter Ivanov, together with talks by the UK Nuclear Decommissioning Authority on the measurements challenges related to decommissioning of legacy nuclear sites, a presentation from Sellafield Ltd on the importance of metrology to storage of special nuclear materials as well as a number of talks given by NPL and the University of Strathclyde on metrological application for nuclear decommissioning. The newly established NPL virtual Centre for Decommissioning Metrology was introduced at the meeting. Figure1: Map of locations of registered conference participants