Verification of nuclear material is paramount in the overall effectiveness of nuclear safeguards. The IAEA is trying to improve the verification process of spent nuclear fuel with advanced data processing techniques. A spent fuel assembly (SFA) can be approximated as a set of 3 m long fuel pins, each about 1 cm in diameter, filled with highly radioactive material. The Passive Gamma Emission Tomography (PGET) instrument was developed by the IAEA, in collaboration with several Member States, for the verification of spent nuclear fuel. The PGET consists of an array of collimated gamma detectors (and two neutron detectors) that are rotated in the horizontal plane. The measurements are performed underwater, with an SFA placed in the centre of the toroidal shaped detector platform.
Presently, the IAEA is able to reliably identify missing pins inside a SFA. However, the IAEA is unable to automatically determine the activity levels of individual pins from the PGET data with high levels of confidence. This becomes exceedingly difficult in certain cases, such as very compact fuel assemblies of fast neutron reactor fuel elements.
The IAEA is seeking new image reconstruction processing techniques, resulting in a more accurate assessment of the locations and count of missing pins, and a more accurate calculation of the relative activities of individual pins.
For more information on this challenge visit the IAEA's challenge website above.