A Review of Nuclear Non-intrusive Visualization Methods in Industry: Computed Tomography and Particle Tracking

The present paper reviews the foundation and application of gamma-ray transmission Computed Tomography (CT) and Radioactive Particle Tracking (RPT) methods in industry. Those methods are primarily useful in oil and petrochemical industries, where processes need to be diagnosed for the purpose of design and/or operating conditions optimization. There are two categories of industrial tomography systems; those using a single source and automatic scanning, and those using multiple sources and/or detectors without mechanical scanning. The main purpose of the latter is to reveal the multidimensional distributions of phases in industrial processes involving multiphase mixtures and flows. Compared to medical tomography temporal resolution is more important for these systems than spatial resolution. Such systems have also been realized using electronic scanning of multiple X-ray sources. Examples on different systems are given. Future developments include dual energy and multiple modality configurations enabling component fraction measurements on multiphase systems. Tomographic methods are also being implemented in permanently installed gauges with a limited number of projections, a priori information and parametric description of the process rather than reconstructed images. Along with the CT techniques, Radioactive Particle Tracking (RPT) is another useful multiphase reactor characterization technique, where it is possible to non-intrusively monitor the Lagrangian trajectories of a single tracer particle faithfully mimicking the phase being investigated. Differentiation of particle trajectories data yields particle instantaneous velocities. Ensemble averaging yields time averaged quantities and the spatial flow field. The instantaneous and time averaged velocities can then be used to determine various turbulence parameters (Reynolds stresses, turbulent kinetic energy, and turbulent eddy diffusivities ...etc.). Detailed description and application examples of RPT are given. Future developments include dual particle tracking and simpler tracking systems. Finally, the paper gives an overview of planned research programs and service capabilities of the nuclear engineering department at King Abdul Aziz University incorporating the reviewed diagnostic tools