Radiographic techniques using muons are attractive for a plethora of diverse applications. Muons are relatively massive elementary particles produced naturally by cosmic rays and can be used as a highly penetrating, non-destructive probe. Muon radiography has been known since the middle of the 20th century and has been used to study very large objects, such as volcanoes, pyramids, tunnels, and mines. Muon scattering tomography, invented in the beginning of the 21st century, is primarily concerned with material identification. Several muon tomography experiments have been carried out at the Fukushima Daiichi plant since 2014. These experiments have provided important insights into the state of the damaged reactors, including the location and distribution of the melted fuel. The information provided by muon tomography has helped to guide the planning and implementation of the decommissioning efforts at the Fukushima Daiichi plant. It has also provided valuable information about the behavior of nuclear fuel during severe accidents, which can inform the design and safety of future
nuclear reactors.
Another application of muon tomography that has gained interest in recent years is dry cask inspection. Muon tomography has been proposed as a non-destructive and non-invasive method for inspecting the internal structure of dry casks. Muon tomography has several advantages over other inspection methods, such as radiography or ultrasonic testing, because it is non-invasive and does not require direct contact with the cask. Research studies and experiments have demonstrated the feasibility and potential of muon tomography for dry cask inspections.
Cosmic-ray tomography represents a new approach for inspection technology — a safe alternative to X-ray and gamma-ray scanners. Methods of the scattering tomography have been developed by Los Alamos National Laboratory and commercialized by Decision Sciences as the Discovery® scanning system. This cutting-edge system is capable of providing a new tool for customs authorities searching for weapons, explosives, shielded nuclear material, smuggled people and various other contraband. It has been successfully deployed around the globe at ports, border crossings and other places. As the largest commercially available muon tomography scanner, the system accommodates cargo containers on commercial trucks. Using advanced image reconstruction techniques it analyzes signals and generates 3-D images of the scanned items. Learning from previous deployments, we continue to enhance the system's imaging capabilities and extend its reach to new customers. Here we discuss recent advancements in muon tomography technology, focusing on machine learning based approaches to accelerate muon tomography reconstructions, enhancing image quality and interpretation through machine learning algorithms and edge sharpening techniques. Additionally, breakthroughs in passive human detection capability offer promising prospects for improving security measures in maritime environments. These developments signify significant strides in enhancing the efficacy and scope of muon tomography in bolstering maritime security and infrastructure resilience.