Verification of completeness of spent nuclear fuel assemblies by means of tomography

摘要: Within the safeguards regime, new technologies are desired to allow for detection of possible diversion individual fuel rods from an irradiated nuclear assembly. A measurement technique, based on Single-Photon Emission Computed Tomography, has been developed and demonstrated a SVEA‑96 BWR assembly, which had one power cycle at Forsmark 2 NPP. Images assembly’s internal distribution gamma-ray emitting isotope 140Ba/140La have obtained tomographically, without requiring assembly be dismantled. Image analysis applied capability detect removal single rod centre demonstrated. In addition, rod-activity reconstructions performed, involving detailed modelling transport through fuel. An agreement 3.1% (1 s) with data production code POLCA‑7 was inspection procedure is suggested where tomographic collected, online image reconstruction performed applied, resulting in preliminary statement completeness less than minute after completed. cases questionable, off-line can highly accurate need additional measurements.