Preliminary results of a spent nuclear fuel internal tomography (SFIT) system

A spent nuclear fuel internal tomography (SFIT) system was proposed to compensate for the loss of radiation data in the central region of the spent nuclear fuel assembly when inspecting using a gamma emission tomography system. The SFIT consists of a scintillation detector and a C-shaped collimator, which rotates inside a guide tube to obtain internal radiation information. This study aims to experimentally verify the feasibility of the SFIT in improving the inspection accuracy of the central region of the spent nuclear fuel assembly. A prototype was implemented, experiments were performed to measure sinograms for four source patterns, and the results were compared and analyzed with simulation results. The feasibility was evaluated by applying the source identification algorithm to verify the ability to identify nuclear fuel rods. The experimental and simulated sinograms for each pattern showed similar trends, verifying the reliability of the experimental results. In conclusion, the feasibility of the SFIT was experimentally verified and the SFIT is expected to be useful as a complementary device for inspecting partial defects in the assembly.