Speaker
Staffan Jacobsson Svärd
(Uppsala University, Uppsala, Sweden)
Description
Gamma emission tomography (GET) for spent nuclear fuel verification is the subject for IAEA MSP project JNT1955. In line with IAEA Safeguards R&D plan 2012-2023, the aim of this effort is to “develop more sensitive and less intrusive alternatives to existing NDA instruments to perform partial defect test on spent fuel assembly prior to transfer to difficult to access storage". The current viability study constitutes the first phase of three, with evaluation and decision points between each phase. Two verification objectives have been identified; (1) counting of fuel pins in tomographic images without any àpriori knowledge of the fuel assembly under study, and (2) quantitative measurements of pin-by-pin properties, e.g. burnup, for the detection of anomalies and/or verification of operator-declared data.
Previous measurements performed in Sweden and Finland have proven GET highly promising for detecting removed or substituted fuel rods in BWR and VVER-440 fuel assemblies even down to the individual fuel rod level. The current project adds to previous experiences by pursuing a quantitative assessment of the capabilities of GET for partial defect detection, across a broad range of potential IAEA applications, fuel types and fuel parameters. A modeling and performance-evaluation framework has been developed to provide quantitative GET performance predictions, incorporating burn-up and cooling-time calculations, Monte Carlo radiation-transport and detector-response modeling, GET instrument definitions (existing and notional) and tomographic reconstruction algorithms, which use recorded gamma-ray intensities to produce images of the fuel’s internal source distribution or conclusive rod-by-rod data. The framework also comprises image-processing algorithms and performance metrics that recognize the inherent tradeoff between the probability of detecting missing pins and the false-alarm rate. Here, the modeling and analysis framework is described and preliminary results are presented.
| Country or International Organization | Sweden |
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Primary author
Staffan Jacobsson Svärd
(Uppsala University, Uppsala, Sweden)
Co-authors
Anna Davour
(Uppsala University, Uppsala, Sweden)
Holly Trellue
(Los Alamos National Laboratory, Los Alamos, NM, USA)
L. Eric Smith
(Pacific Northwest National Laboratory, Richland, WA, USA)
Nikhil Deshmukh
(Pacific Northwest National Laboratory, Richland, WA, USA)
PETER JANSSON
(UPPSALA UNIVERSITY)
Richard S. Wittman
(Pacific Northwest National Laboratory, Richland, WA, USA)
Sophie Grape
(Uppsala University)
Timothy A. White
(Pacific Northwest National Laboratory, Richland, WA, USA)
Vladimir Mozin
(Lawrence Livermore National Laboratory, Livermore, CA, USA)
