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Davour, Anna
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Publications (10 of 75) Show all publications
Jacobsson, S., Smith, E., White, T. A., Mozin, V., Jansson, P., Andersson, P., . . . Ely, J. (2017). Outcomes of the JNT 1955 Phase I Viability Study of Gamma Emission Tomography for Spent Fuel Verification. ESARDA Bulletin (55), 10-28
Open this publication in new window or tab >>Outcomes of the JNT 1955 Phase I Viability Study of Gamma Emission Tomography for Spent Fuel Verification
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2017 (English)In: ESARDA Bulletin, ISSN 1977-5296, no 55, p. 10-28Article in journal (Refereed) Published
Abstract [en]

The potential for gamma emission tomography (GET) to detect partial defects within a spent nuclear fuel assembly has been assessed within the IAEA Support Program project JNT 1955, phase I, which was completed and reported to the IAEA in October 2016. Two safeguards verification objectives were identified in the project; (1) independent determination of the number of active pins that are present in a measured assembly, in the absence of a priori information about the assembly; and (2) quantitative assessment of pin-by-pin properties, for example the activity of key isotopes or pin attributes such as cooling time and relative burnup, under the assumption that basic fuel parameters (e.g., assembly type and nominal fuel composition) are known. The efficacy of GET to meet these two verification objectives was evaluated across a range of fuel types, burnups and cooling times, while targeting a total interrogation time of less than 60 minutes.

The evaluations were founded on a modelling and analysis framework applied to existing and emerging GET instrument designs. Monte Carlo models of different fuel types were used to produce simulated tomographer responses to large populations of "virtual" fuel assemblies. The simulated instrument response data were then processed using a variety of tomographic-reconstruction and image- processing methods, and scoring metrics were defined and used to evaluate the performance of the methods.

This paper describes the analysis framework and metrics used to predict tomographer performance. It also presents the design of a "universal" GET (UGET) instrument intended to support the full range of verification scenarios envisioned by the IAEA. Finally, it gives examples of the expected partial-defect detection capabilities for some fuels and diversion scenarios, and it provides a comparison of predicted performance for the notional UGET design and an optimized variant of an existing IAEA instrument.

Keywords
Spent nuclear fuel assemblies, Partial defect verification, Gamma-ray emission tomography
National Category
Subatomic Physics
Research subject
Physics with specialization in Applied Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-347213 (URN)
Funder
Swedish Radiation Safety Authority
Available from: 2018-03-27 Created: 2018-03-27 Last updated: 2018-04-19Bibliographically approved
Smith, E. L., Jacobsson, S., Mozin, V., Jansson, P., Miller, E., Honkamaa, T., . . . Holcombe, S. (2016). A Viability Study of Gamma Emission Tomography for Spent Fuel Verification: JNT 1955 Phase I Technical Report.
Open this publication in new window or tab >>A Viability Study of Gamma Emission Tomography for Spent Fuel Verification: JNT 1955 Phase I Technical Report
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2016 (English)Report (Refereed)
Abstract [en]

The potential for gamma emission tomography (GET) to detect partial defects within a spent nuclear fuel assembly is being assessed through a collaboration of Support Programs to the International Atomic Energy Agency (IAEA). In the first phase of this study, two safeguards verification objectives have been identified. The first is the independent determination of the number of active pins that are present in the assembly, in the absence of a priori information about the assembly. The second objective is to provide quantitative assay of pin-by-pin properties, for example the activity of key isotopes or pin attributes such as cooling time and relative burnup, under the assumption that basic fuel parameters (e.g., assembly type and nominal fuel composition) are known. The efficacy of GET to meet these two verification objectives has been evaluated across a range of fuel types, burnups, and cooling times, and with a target total interrogation time of less than 60 minutes. This evaluation of GET viability for safeguards applications was founded on a modelling and analysis framework applied to existing and emerging GET instrument designs. Monte Carlo models of different fuel types were used to produce simulated tomographer responses to large populations of “virtual” fuel assemblies. Instrument response data were processed using a variety of tomographic-reconstruction and image-processing methods, and scoring metrics specific to each of the verification objectives were used to predict performance. This report describes the analysis framework and metrics used to predict tomographer performance, the design of a “universal” GET (UGET) instrument intended to support the full range of verification scenarios envisioned by the IAEA, and a comparison of predicted performance for the notional UGET design and an optimized variant of an existing IAEA instrument.

Publisher
p. 119
Series
PNNL Report ; PNNL-25995
National Category
Subatomic Physics
Research subject
Physics with specialization in Applied Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-306584 (URN)
Available from: 2016-10-29 Created: 2016-10-29 Last updated: 2018-04-19Bibliographically approved
Davour, A., Jacobsson Svärd, S., Andersson, P., Grape, S., Holcombe, S., Jansson, P. & Troeng, M. (2016). Applying image analysis techniques to tomographic images of irradiated nuclear fuel assemblies. Annals of Nuclear Energy, 96, 223-229
Open this publication in new window or tab >>Applying image analysis techniques to tomographic images of irradiated nuclear fuel assemblies
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2016 (English)In: Annals of Nuclear Energy, ISSN 0306-4549, E-ISSN 1873-2100, Vol. 96, p. 223-229Article in journal (Refereed) Published
Abstract [en]

In this paper we present a set of image analysis techniques used for extraction of information from cross-sectional images of nuclear fuel assemblies, achieved from gamma emission tomography measurements. These techniques are based on template matching, an established method for identifying objects with known properties in images.

We demonstrate a rod template matching algorithm for identification and counting of the fuel rods present in the image. This technique may be applicable in nuclear safeguards inspections, because of the potential of verifying the presence of all fuel rods, or potentially discovering any that are missing.

We also demonstrate the accurate determination of the position of a fuel assembly, or parts of the assembly, within the imaged area. Accurate knowledge of the assembly position enables detailed modelling of the gamma transport through the fuel, which in turn is needed to make tomographic reconstructions quantifying the activity in each fuel rod with high precision.

Using the full gamma energy spectrum, details about the location of different gamma-emitting isotopes within the fuel assembly can be extracted. We also demonstrate the capability to determine the position of supporting parts of the nuclear fuel assembly through their attenuating effect on the gamma rays emitted from the fuel. Altogether this enhances the capabilities of non-destructive nuclear fuel characterization.

Keywords
Nuclear fuel, Image analysis, Gamma emission tomography, Nuclear safeguards
National Category
Subatomic Physics
Research subject
Physics with specialization in Applied Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-295146 (URN)10.1016/j.anucene.2016.05.024 (DOI)000380600300025 ()
External cooperation:
Funder
Swedish Radiation Safety Authority, SSM 2013-85-9, SSM 2014-94, SSM 2015-99
Available from: 2016-06-03 Created: 2016-06-03 Last updated: 2018-04-19Bibliographically approved
Davour, A., Jacobsson, S. S. & Grape, S. (2015). Image analysis methods for partial defect detection using tomographic images on nuclear fuel assemblies. In: : . Paper presented at 37th annual ESARDA Symposium, 19 - 21 May 2015, Manchester, UK.
Open this publication in new window or tab >>Image analysis methods for partial defect detection using tomographic images on nuclear fuel assemblies
2015 (English)Conference paper, Published paper (Other academic)
Abstract [en]

A promising non-destructive assay method for verification of irradiated nuclear fuel is gammatomography, i.e. the use of measurements of the gamma radiation field around a nuclear fuel assembly to reconstruct detailed information about the internal source distribution.

Typically, tomographic reconstructions result in two-dimensional images of cross sections of the fuel. We demonstrate how such images can be searched for fuel rods using a template matching technique, which is a method commonly used in the field of image analysis. In this case, a template or mask corresponding to the size and shape of a fuel rod is translated across the image in order to find the region with the highest reconstructed activity, which is assumed to correspond to the location of a fuel rod in the image. This is done iteratively, allowing no overlap of the rods. By defining the threshold between background and fuel rod objects in the image, we can identify and count the fuel rods using no other assumptions than the rod radius.

Thus the rod identification procedure provides a possible means to verify whether all fuel rods arepresent, and it may also be implemented to identify the fuel type of the measured assembly. Theprocedure is robust in cases of irregularities, such as assembly bow or torsion, or the dislocation ofindividual fuel rods in the measured cross section.

Here we demonstrate fuel rod identification procedure, using authentic images collected with a tomographic measurement device on commercial fuel assemblies. The results show that image analysis can support tomographic partial defect verification of irradiated nuclear fuel assemblies, even on the single fuel rod level.

Keywords
image analysis, nuclear fuel, partial defect verification, nuclear safeguards, gamma emission tomography
National Category
Subatomic Physics
Research subject
Physics with specialization in Applied Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-253709 (URN)
Conference
37th annual ESARDA Symposium, 19 - 21 May 2015, Manchester, UK
Projects
UGET
Funder
Swedish Radiation Safety Authority
Available from: 2015-06-01 Created: 2015-06-01 Last updated: 2018-05-29Bibliographically approved
White, T. A., Jacobsson Svärd, S., Smith, E., Mozin, V., Jansson, P., Davour, A., . . . Ely, J. (2015). Passive Tomography for Spent Fuel Verification: Analysis Framework and Instrument Design Study. In: : . Paper presented at ESARDA Symposium 2015.
Open this publication in new window or tab >>Passive Tomography for Spent Fuel Verification: Analysis Framework and Instrument Design Study
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2015 (English)Conference paper, Published paper (Other academic)
Abstract [en]

The potential for gamma emission tomography (GET) to detect partial defects within a spent nuclearfuel assembly is being assessed through a collaboration of Support Programs to the InternationalAtomic Energy Agency (IAEA). In the first phase of this study, two safeguards verification objectiveshave been identified. The first is the independent determination of the number of active pins that arepresent in the assembly, in the absence of a priori information. The second objective is to providequantitative measures of pin-by-pin properties, e.g. activity of key isotopes or pin attributes such ascooling time and relative burnup, for the detection of anomalies and/or verification of operator-declareddata. The efficacy of GET to meet these two verification objectives will be evaluated across a range offuel types, burnups, and cooling times, and with a target interrogation time of less than 60 minutes.

The evaluation of GET viability for safeguards applications is founded on a modelling and analysisframework applied to existing and emerging GET instrument designs. Monte Carlo models of differentfuel types are used to produce simulated tomographer responses to large populations of “virtual” fuelassemblies. Instrument response data are processed by a variety of tomographic-reconstruction andimage-processing methods, and scoring metrics specific to each of the verification objectives aredefined and used to evaluate the performance of the methods. This paper will provide a description ofthe analysis framework and evaluation metrics, example performance-prediction results, and describethe design of a “universal” GET instrument intended to support the full range of verification scenariosenvisioned by the IAEA.

National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-265892 (URN)
Conference
ESARDA Symposium 2015
Available from: 2015-11-03 Created: 2015-11-03 Last updated: 2018-04-19
Jansson, P., Jacobsson Svärd, S., Grape, S., Davour, A. & Mozin, V. (2014). Gamma Transport Calculations for Gamma Emission Tomography on Nuclear Fuel within the UGET Project. In: : . Paper presented at IAEA Symposium on International Safeguards: Linking Strategy, Implementation and People.
Open this publication in new window or tab >>Gamma Transport Calculations for Gamma Emission Tomography on Nuclear Fuel within the UGET Project
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2014 (English)Conference paper, Published paper (Other academic)
Abstract [en]

The unattended gamma emission tomography (UGET) for spent nuclear fuel verification is an on-going project in the IAEA member states’ support program. In line with the long term R&D plan of the IAEA Department of Safeguards, it is anticipated that this effort will help 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”.

In the first phase of the project, gamma transport calculations and modelling of exist- ing and proposed new designs of tomographic instruments is performed. In this paper, a set of Monte Carlo calculations regarding modelling of various tomographic devices are presented, including two existing tomographic instruments previously used for spent fuel measurements; one instrument based on scintillator detectors, developed by Uppsala University, and another based on CdTe detector arrays, developed by the JNT 1510 col- laborative effort (Hungary, Finland). Detailed models of the tomographic instruments, including structural materials, and the measured fuel assemblies are used in the simula- tions. The calculated results are compared to the experimentally measured data to provide a benchmark for the simulation procedure.

The developed modelling capabilities are also used for evaluation of the partial-defect detection capabilities of the tomographic technique based on a proposed GET instrument design. 

National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-238696 (URN)
Conference
IAEA Symposium on International Safeguards: Linking Strategy, Implementation and People
Available from: 2014-12-15 Created: 2014-12-15 Last updated: 2018-04-19
Jacobsson Svärd, S., White, T. A., Smith, E., Mozin, V., Jansson, P., Davour, A., . . . Wittman, R. S. (2014). Gamma-ray Emission Tomography: Modelling and evaluation of partial-defect testing capabilities. In: : . Paper presented at IAEA Symposium on International Safeguards: Linking Strategy, Implementation and People.
Open this publication in new window or tab >>Gamma-ray Emission Tomography: Modelling and evaluation of partial-defect testing capabilities
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2014 (English)Conference paper, Published paper (Other academic)
Abstract [en]

Assessment of gamma emission tomography (GET) for spent nuclear fuel verification is the task in 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 tests on spent fuel assemblies 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 a priori 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 pins (i.e. partial defects) in BWR and VVER-440 fuel assemblies even down to the individual fuel pin 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 modelling 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 modelling, GET instrument definitions (existing and notional) and tomographic reconstruction algorithms, which use recorded gamma-ray intensities to produce cross-sectional images of the source distribution in the fuel assembly or conclusive pin-by-pin data. The framework also comprises image-processing algorithms and performance metrics that recognize the inherent trade-off between the probability of detecting missing pins and the false-alarm rate. Here, the modelling and analysis framework is described and preliminary results are presented. 

National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-239893 (URN)
Conference
IAEA Symposium on International Safeguards: Linking Strategy, Implementation and People
Available from: 2015-01-03 Created: 2015-01-03 Last updated: 2018-04-19
Håkansson, A., Davour, A., Grape, S., Hellesen, C., Höök, M., Lantz, M., . . . Qvist, S. (2014). Svensk elförsörjning i framtiden – en fråga med globala dimensioner: En tvärvetenskaplig rapport från Uppsala universitet. Uppsala
Open this publication in new window or tab >>Svensk elförsörjning i framtiden – en fråga med globala dimensioner: En tvärvetenskaplig rapport från Uppsala universitet
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2014 (Swedish)Report (Other academic)
Place, publisher, year, edition, pages
Uppsala: , 2014. p. 66
National Category
Economic History Subatomic Physics
Research subject
Physics with specialization in Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-233392 (URN)
Available from: 2014-10-02 Created: 2014-10-02 Last updated: 2015-01-08Bibliographically approved
Botner, O., Bouchta, A., Davour, A., Hallgren, A., Lundberg, J. & Perez de los Heros, C. (2006). A New Search Paradigm for Correlated Neutrino Emission from Discrete GRBs using Antarctic Cherenkov Telescopes in the Swift Era. In: 16th Annual Astrophysics Conference in Maryland: Gamma Ray Bursts in the Swift Era.
Open this publication in new window or tab >>A New Search Paradigm for Correlated Neutrino Emission from Discrete GRBs using Antarctic Cherenkov Telescopes in the Swift Era
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2006 (English)In: 16th Annual Astrophysics Conference in Maryland: Gamma Ray Bursts in the Swift Era, 2006Conference paper, Published paper (Other scientific)
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-78707 (URN)
Available from: 2006-03-29 Created: 2006-03-29
Botner, O., Bouchta, A., Conrad, J., Davour, A., Hallgren, A., Lundberg, J., . . . Perez de los Heros, C. e. (2006). Design and Production of the IceCube Digital Optical Module. In: Fourth International Conference on New Developments in Photodetection, Beaune, France 19-24 June 2005.
Open this publication in new window or tab >>Design and Production of the IceCube Digital Optical Module
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2006 (English)In: Fourth International Conference on New Developments in Photodetection, Beaune, France 19-24 June 2005, 2006Conference paper, Published paper (Other scientific)
Keywords
AMANDA, IceCube, neutrino, telescope, astroparticle
Identifiers
urn:nbn:se:uu:diva-24705 (URN)
Available from: 2007-02-06 Created: 2007-02-06
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