Feasibility study of in-sodium imaging technique employing gamma-ray emission

In order to enhance the maintenance performance of Sodium-Cooled Fast Reactors (SFRs), the authors has proposed a novel in-sodium imaging technique for monitoring a deformation or a displacement of in-sodium components or assemblies in primary cooling systems. This technique is based on computed tomography using high-energy gamma photons emitted from radioisotopes of sodium (22Na, 24Na) in the primary coolant. Feasibility studies have been performed to explore the applicability to typical piping (or vessels). Preliminary analyses exploring measuring time and imaging capability were performed. The results showed that the proposed technique was feasible as a monitoring system of in-sodium components. (authors)