Our paper examines isotopic activity ratios of radionuclides detected at radionuclide stations within the International Monitoring System (IMS) for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). We focus on characterizing release events from underground nuclear explosions by analyzing radionuclide concentrations in air plumes sampled by IMS stations. The study investigates decay correction during sampling, using two approaches: interval constant concentration and decaying concentration. Our findings highlight the impact of these methods on isotopic activity ratios, particularly for radionuclides with short half-lives. Read the full paper here: https://www.doi.org/10.1007/s00024-025-03716-z

What about radioxenon discharges from Spent Nuclear Fuel (SNF) reprocessing plants? Do these emissions cause a background in the atmosphere that may be detected by noble gas systems of the International Monitoring System (IMS) operated by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) for nuclear explosion monitoring? This type of nuclear facilities has not been investigated before. But we did it. Thanks to an excellent team of co-authors: Tatiana Boitsova, Jolanta Kusmierczyk Michulec & Carla Maria Salgueiro Pires Winter. It is a great pleasure working with you. Take a look at our article: https://www.doi.org/10.1007/s00024-025-03691-5

Our literature review on historic atmospheric radionuclide monitoring data associated with nuclear explosions is eventually published. It covers reports on tests conducted by four countries between 1964 and 1996 and those related to the six announced nuclear tests of the Democratic People’s Republic of Korea between 2006 and 2017. Most of these nuclear explosions occurred in the atmosphere, but observation of nuclear debris from the venting of underground nuclear tests was also found. The review is limited to off-site monitoring. Many observations were done at large distances, including several nuclear explosions detected in multiple locations, generally in the same hemisphere. The measurement methods developed over time, and many different fission…