Partial Defect Tester: A Novel Approach to Detect Partial Defects in Pressurized Water Reactor Spent Fuel

Identification of Diversions in Spent Pwr Fuel Assemblies by Pdet Signatures Using Artificial Neural Networks (Anns)

“…An approach for safeguards inspections of SNF assemblies is based on the Partial Defect Tester (PDET). The first prototype of the PDET was developed by Lawrence Livermore National Laboratory and consists of a set of neutron fission chambers and gamma-ray ionization chambers that can be inserted in the guide tubes of assemblies of Pressurized Water Reactors (PWRs) (Sitaraman and Ham, 2007;Ham and Sitaraman, 2011;Ham et al, 2015). The measured quantities from the PDET are the passive emission of neutrons and gamma-rays taken at the empty guide tube positions in the SNF assembly.…”

“…In (PWRs). For this purpose, a synthetic dataset is used and includes simulated neutron and gamma measurements according to the Partial Defect Tester (PDET), an inspection technique developed by Lawrence Livermore National Laboratory (Sitaraman and Ham, 2007;Ham and Sitaraman, 2011;Ham et al, 2015). The specific objective is to study the performance of two ANN models for the prediction of the total amount of replaced fuel pins within a SNF assembly and for the determination of the exact diversion pattern, respectively.…”

Nondestructive Assay Options for Spent Fuel Encapsulation

“…Information regarding BU and CT is also obtained. It is expected that diversion of ~10% of the mass can be detected (Ham and Sitaraman 2011).…”

“…Left, (Ham et al 2010): Photograph of a prototype PDET system. Right, (Ham and Sitaraman 2011): Simulated and measured PDET data. The "normalized ratio" is the normalized gamma-to-neutron count rate.…”

“…Research Institute (KAERI), some pins were not present (Ham and Sitaraman 2011). The "Sim" and Meas" curves in Figure 5-22 are the simulated and measured results with 22 pins (12% of the mass) missing, respectively.…”