Discrimination of high-Z materials in concrete-filled containers using muon scattering tomography

Abstract

General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms Abstract: An analysis method of identifying materials using muon scattering tomography is presented, which uses previous knowledge of the position of high-Z objects inside a container and distinguishes them from similar materials. In particular, simulations were performed in order to distinguish a block of Uranium from blocks of Lead and Tungsten of the same size, inside a concrete-filled drum. The results show that, knowing the shape and position from previous analysis, it is possible to distinguish 5 × 5 × 5 cm 3 blocks of these materials with about 4h of muon exposure, down to 2 × 2 × 2 cm 3 blocks with 70h of data using multivariate analysis (MVA). MVA uses several variables, but it does not benefit the discrimination over a simpler method using only the scatter angles. This indicates that the majority of discrimination is provided by the angular information. Momentum information is shown to provide no benefits in material discrimination.

A novel technique for finding gas bubbles in the nuclear waste containers using Muon Scattering Tomography

“…The distributions are clearly distinct. Empty drums (low-Z material inside vessel) can be clearly distinguished from concrete-filled drums (higher-Z material inside vessel) as low-Z material is Figure 3: Geometry used in simulations [10]. Each RPC measures 100x100 cm 2 .…”

“…However, it is a useful approximation, since it nonetheless provides a roughly correct localization of the area of the muon scattering for the larger scattering events used in our method. The methods presented in [8], [10], [21] were developed for detecting and distinguishing small lumps of high-Z materials and measure their size. Here, the method was further developed and used to distinguish low-Z (gas) from a higher-Z (concrete-like) material and measuring the size of gas bubbles.…”

“…The distance between the upper and the lower RPC pairs is 548 mm. The RPCs strips have a pitch of 1.5 mm [10]. In addition, we defined a cylindrical waste drum with the radius of 13 cm and length of 40 cm, which was placed between the top and bottom half of the detector system.…”

Non-destructive assay of nuclear waste containers using muon scattering tomography in the Horizon2020 CHANCE project

“…In the past, this has been exploited for various discrimination and identification studies in simulation: to differentiate between different high-Z materials [3], [5] or to locate gas bubbles in bitumen-filled drums [6].…”

A quantitative assessment of Imaging High-Z and Medium-Z materials using Muon Scattering Tomography

“…Using a non-invasive technique to assay nuclear waste packages could beneficially reduce the cost involved in opening the investigated packages, as well as mitigate against any potential risk of being exposed to ionising radiation. Muon scattering tomography (MST) is a non-destructive imaging method that has proven valuable for imaging hidden objects in many applications, such as nuclear safeguards and nuclear waste management [1,2].…”