TY - JOUR
AU - Brücken, J.E.
AB - We are evaluating the performance of a Passive Gamma Emission Tomography (PGET) device [1] equipped with 3D position-sensitive cadmium zinc telluride (CZT) gamma-ray detectorswhen used for inspecting spent nuclear fuel assemblies (SFAs). Before their disposal in ageological repository, SFAs undergo verification using the PGET device, which was developed underthe guidance of the IAEA and approved by the IAEA for safeguards inspections. Recent advancementsin imaging detector technology may offer a method to extend the capabilities of such devicesbeyond standard safeguards applications, allowing an efficient non-invasive way to accuratelycharacterise the properties of nuclear fuel assemblies.  The efficiency of the currently usedsmall CZT detectors is restricted by the limited likelihood of full gamma-ray absorption, which isneeded for optimal imaging information. Employing larger CZT detectors would increase theprobability of capturing the full energy of gamma rays, thereby enhancing the sensitivity of thePGET device and the quality of the reconstructed images. Large CZT detectors need to beposition-sensitive to determine through which collimator slit a gamma ray travelled. Positionsensitivity results from the pixelated readout of the CZT crystals. Pixelation potentiallyincreases the spatial resolution of the system, which is currently determined by the collimatorused. Pixelation allows resolving the position of arrival up to (readout pitch)/√(12). Weare additionally exploring the potential of utilising Compton imaging to provide information onthe origin of gamma rays along the SFA.  Monte Carlo simulations are used to estimate the increasein full photon absorption efficiency when comparing large and current, small, crystals. Adedicated simulation is created using Geant4, where gamma rays of energy 661.7 keV and 1274 keVare targeted to the model describing the approved apparatus now equipped with 22 mm × 22 mm × 10 mm crystals of CZT. It is observed that the efficiency for photon absorption in this case isgreatly increased when compared to the existing detectors.  
TI - Nuclear fuel imaging using position-sensitive detectors
JF - The Planetary Science Journal
DO - 10.1088/1748-0221/20/03/c03012
DA - 2025-03-01
UR - https://www.deepdyve.com/lp/iop-publishing/nuclear-fuel-imaging-using-position-sensitive-detectors-tqVH8UTjqC
VL - 20
IS - 03
DP - DeepDyve
ER -