Description
E-poster session with display of each e-poster on an assigned touchscreen
The automated particulate and HPGe noble gas analysis engine, Autosaint, has been in use at the IDC for over a decade. This code is one of the last remaining radionuclide processing algorithms written in C, with all other key applications either developed in or ported to Python 3. For long-term maintainability and consistency, the functions performed by this module will be redeveloped and...
Bundesamt für Strahlenschutz (BfS) has been operating a network with weekly air sample collection at up to 26 locations in Germany and worldwide, with sampling going back to 1973. The samples are analyzed for Kr-85 at the BfS Noble Gas laboratory in Freiburg which is accredited according to DIN EN ISO/IEC 17025. Large quantities of the radioactive noble gas Kr-85 are released into the...
Observation of several unusual air activation radioxenon isotopes during Xenon International acceptance testing has raised questions about whether similar detections have gone unnoticed within the IMS. PNNL has begun developing algorithms to assist in identifying if such anomalous analytes are present. The algorithms and their efficacy will be addressed in the presentation.
The Swedish Xenon Array is a first-of-its-kind measurement system, consisting of five SAUNA QB units placed around Sweden with an inter-distance around one order of magnitude smaller than the IMS. We here present a comprehensive analysis of the first two years of data (2021-2022), where xenon background sources relevant to Sweden and northern Europe are characterized, and a comparison of the...
In early September 2024, the particulate radionuclide IMS station in Stockholm, Sweden, observed several anomalous measurements of caesium-137. Similarly unusual detections were simultaneously being observed on national monitoring networks across Europe, and preliminary investigations suggested that the source of the fission products was somewhere in Eastern Europe. In time, it became apparent...
The Sahel is that band of Africa laying between 12°N and 20°N with a semi-arid region separating the Sahara desert from the Sudanian tropical savanna. The Comprehensive Nuclear-Test-Ban Treaty (CTBT) bans any testing of nuclear explosive devices which is carried out underground, in the atmosphere and underwater. Two main technologies, radionuclide and seismo-acoustic monitoring, are deployed...
Monitoring atmospheric radioxenon concentration is crucial for verifying compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT) and may confirm the nuclear nature of an underground explosion. The International Monitoring System (IMS) collects and analyzes air samples to determine the activity concentrations of four radioxenon nuclides (131mXe, 133mXe, 133Xe, 135Xe). Multiple civil...
In 2011, the Fukushima nuclear disaster was a big accident and the approximate cause is the Tohoku earthquake and tsunami. In the days after the accident, radiation was released into the atmosphere and water, and caesium was detected at IMS particulate stations. Caesium (Cs) is a chemical element in the periodic table with atomic number 55 and 40 known isotopes. This study presents the...
Modern radioxenon detection systems exhibit a low memory effect. For example, the MIKS plastic detector cell has a memory effect coefficient of less than 5%. However, even low levels of memory effect can affect measurement results. To account for this, the gas background is measured separately and incorporated into the calculation of sample activity.
Accurate accounting for the gas...
The International Monitoring System (IMS) is a global network that when complete will consist of 16 laboratories and 321 monitoring stations providing real-time data delivering insights to the nuclear explosion monitoring community. A thorough comparison of results produced by these monitoring systems and labs has been conducted utilising data from multiple years of Radionuclide Laboratory...
Pacific Northwest National Laboratory (PNNL) is developing a comprehensive database of over 100,000 analyzed gamma-ray spectra from an archive from decades of radiometric analysis of a diverse range of radionuclide samples by trained gamma spectroscopists. This dataset will be leveraged to embed domain expert interpretation and analysis of gamma-ray spectra into trained semi-supervised...
Artificial intelligence machine learning (AI/ML) tools have the potential to greatly streamline gamma spectral analysis for a variety of applications including nuclear forensics and nuclear explosion monitoring (NEM). Models are being trained with hundreds of thousands of previously analyzed gamma spectra by experts at Pacific Northwest National Laboratory (PNNL) and the CTBTO PrepCom. These...
One of the aims of using Atmospheric Transport Modelling (ATM) in National Data Centres (NDC) is to locate the geographical areas likely to contain the source at the origin of a set of measurements at International Monitoring System (IMS) stations, and to provide an estimate of the associated release quantity. One of the main challenges lies in uncertainty quantification. For this purpose,...
High resolution gamma spectrometry allows least-squares-based net area calculation in radioactive xenon detections. The least-squares-based calculation accounts for X-ray deconvolution and gamma peak area quantification. The International Data Centre (IDC) has been seeking a new approach to enhance the capability of gamma area quantification by taking advantage of X-ray counts. In a previous...
Argon-37 is a signature of interest for nuclear explosion monitoring because its longer half-life compared to radioxenon isotopes provides a longer detection window and it is produced in underground nuclear explosions (UNEs) with high enough activity to be detected using current detection systems. 37Ar is produced in UNEs through the neutron activation of 40Ca in rock and soil. The thermal...
Under a collaboration known as Xenon and Environmental Radionuclide Analysis at Hartlepool (XENAH), an advanced gas-cooled nuclear reactor based in the UK has granted access to real-time monitoring data of the gaseous CO2 primary coolant. These data, partly intended to inform station operators as to the state of health of the core, represent a vast repository that may be further explored for...
The CTBTO’s International Data Centre (IDC) collects, processes and analyses data originating from the facilities of the CTBTO’s International Monitoring System (IMS), which uses four complementary verification methods (including radionuclide) to detect nuclear explosions. Radionuclide technique is the last step to validate whether a nuclear explosion has been carried out. Data from the 73...
With the establishment of radioxenon detector networks, such as the IMS, a long-standing challenge has been to accurately correlate individually detected samples that share a common source. Traditional methods, relying on classifications by human operators or simplistic time-based connections, can be time-consuming and prone to biases and oversimplifications. To address these issues, we...
Development of methods to reliably and accurately calibrate fielded radioxenon systems is more important than ever due to the newest generation of radioxenon systems driving detection sensitivity levels ever lower. This presentation will discuss measurement accuracy when using simulated data for calibrations. An assessment of system accuracy and detection sensitivity using simulated data,...
One of the common methods to interpret radioxenon data is by using a Multiple Isotope Ratio Chart (MIRC). A MIRC enables classification of isotopic ratios into domains corresponding to either civilian activities or nuclear explosion events. This tool is invaluable for distinguishing between different sources of radioxenon, thereby aiding in identifying potential nuclear activities. Two of the...
Radioxenon detection is one of the key methods used in the International Monitoring System (IMS) of CTBTO for detecting a nuclear explosion event. However, since there are numerous civilian sources of radioxenon, such as isotope production facilities and nuclear power plants, any detection of radioxenon must be carefully analysed in order to determine if the source could be a nuclear...
