Verification of completeness of spent nuclear fuel assemblies by means of tomography
2008 (English)In: International Conference on the Physics of Reactors: Nuclear Power: A Sustainable Resource, Switzerland: Paul Scherrer Institute , 2008Conference paper (Other academic)
Within the safeguards regime, new technologies are desired to allow for detection of possible diversion of individual fuel rods from an irradiated nuclear fuel assembly.
A measurement technique, based on Single-Photon Emission Computed Tomography, has been developed and demonstrated on a SVEA‑96 BWR assembly, which had been irradiated for one power cycle at the Forsmark 2 NPP. Images of the assembly’s internal distribution of the gamma-ray emitting isotope 140Ba/140La have been obtained tomographically, without requiring the assembly to be dismantled. Image analysis has been applied and the capability to detect the removal of a single rod from the assembly centre has been demonstrated.
In addition, rod-activity reconstructions have been performed, involving detailed modelling of the gamma-ray transport through the fuel. An agreement of 3.1% (1 s) with data from the production code POLCA‑7 was demonstrated.
An inspection procedure is suggested where tomographic data is collected, online image reconstruction is performed and image analysis is applied, resulting in a preliminary statement of the assembly’s completeness less than a minute after the measurement is completed. In cases where the completeness is questionable, an off-line rod-activity reconstruction can be performed, resulting in highly accurate data without the need for additional measurements.
Place, publisher, year, edition, pages
Switzerland: Paul Scherrer Institute , 2008.
Tomography, nuclear fuel, safeguards, partial defect verification
Research subject Physics with specialization in Applied Nuclear Physics
IdentifiersURN: urn:nbn:se:uu:diva-146745ISBN: 978-3-9521409-5-6OAI: oai:DiVA.org:uu-146745DiVA: diva2:398897
PHYSOR 2008, Interlaken, Switzerland