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- Jansson, Peter, 1971-, et al.
(författare)
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Axial and azimuthal gamma scanning of nuclear fuel - implications for spent fuel characterization
- 2016
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Ingår i: Journal of Nuclear Materials Management. - 0893-6188. ; 45:1, s. 34-47
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Tidskriftsartikel (refereegranskat)abstract
- A project to research the application of non-destructive assay (NDA) to spent fuel assemblies is underway among a team comprised of the European Commission, DG Energy, Directorate Nuclear Safeguards; the Swedish Nuclear Fuel and Waste Management Company; Uppsala University, The University of Michigan, Los Alamos National Laboratory, Lawrence Livermore National Laboratory and Oak Ridge National Laboratory that collaboratively are advancing some of the goals of the Next Generation Safeguards Initiative’s Spent Fuel (NGSI-SF) Project. The NGSI–SF team is working to achieve the following technical goals more easily and efficiently using nondestructive assay measurements of spent fuel assemblies in order to improve both international safeguards and repository safety: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. The measured neutron, gamma-ray and heat signatures from spent fuel assemblies, as well as simulations, will be combined in advancement of the technical goals.This current study focuses primarily on the application of time stamped list mode data acquisition applied in the context of a fixed collimator that allowed a thin axial portion of the fuel to be observed as the fuel assembly moved vertically past the collimator. Measurements were performed at the Central Interim Storage Facility for Spent Nuclear Fuel (which is abbreviated using the Swedish acronym: Clab) in Sweden, in 2013 and 2014. In total, 50 spent nuclear fuel assemblies were measured in detail, 25 BWR and 25 PWR assemblies.In this context, time stamped list mode data acquisition have not previously been used for gamma-ray spectroscopy measurements of used nuclear fuel measurements. We compare it to the more typical fixed-axial location pulse height analysis approach. The flexibility of analyzing data from time stamped list mode measurements enables research into questions of how beneficial axially resolved information is for each of the varied research goals; in particular the current research is an initial step toward comparing the benefit of several fixed axial measurements vs. scanning an entire assembly.
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| 2. |
- Tobin, Stephen, et al.
(författare)
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Nondestructive Assay Data Integration with the SKB-50 Assemblies - FY16 Update
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A project to research the application of non-destructive assay (NDA) techniques for spent fuel assemblies is underway at the Central Interim Storage Facility for Spent Nuclear Fuel (for which the Swedish acronym is Clab) in Oskarshamn, Sweden. The research goals of this project contain both safeguards and non-safeguards interests. These nondestructive assay (NDA) technologies are designed to strengthen the technical toolkit of safeguard inspectors and others to determine the following technical goals more accurately; Verify initial enrichment, burnup, and cooling time of facility declaration for spent fuel assemblies; Detect replaced or missing pins from a given spent fuel assembly to confirm its integrity; and Estimate plutonium mass and related plutonium and uranium fissile mass parameters in spent fuel assemblies. Estimate heat content, and measure reactivity (multiplication).
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| 3. |
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| 4. |
- Tobin, Stephen, et al.
(författare)
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Research into Measured and Simulated Nondestructive Assay Data to Address the Spent Fuel Assay Needs of Nuclear Repositories
- 2016
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) Project started in 2009 with the intent to integrate nondestructive assay (NDA) signals in order to improve safeguards verification capabilities. This paper researches the integration of the following: (1) spectral-resolved passivegamma [ 154Eu and 137Cs], (2) total neutron and (3) Passive Neutron Albedo Reactivity (PNAR) in the context of encapsulation/repository facilities. For the first two NDA techniques listed, measured and simulated results are available, while for PNAR only simulated results are currently available.The measured results are from the Central Interim Storage Facility for Spent Nuclear Fuel (Clab) in Sweden where 50 spent fuel assemblies were measured in 2014 and 2015. The PNAR instrument is one of four non-traditional, spent fuel NDA techniques to be deployed at Clab in 2016 and 2017. The inclusion of these non-traditional instruments, capable of estimating properties such as within-assembly neutron multiplication, makes this research unique and offers promising improvements to the current safeguards toolkit. Goals of the NGSI-SF Project include: (1) verifying the initial enrichment, burnup,and cooling time of the facility declaration; (2) detecting diversion or replacement of pins, (3) estimating the plutonium mass. Additional project goals that are concurrent with SKB’s interests are (4) estimating the decay heat, and (5) determining the multiplication/reactivity of spent fuel assemblies. In this paper, data mining techniques are applied to integrate both simulated and measured passive gamma and total neutron signals with the simulated PNAR signals to estimate various quantities for safeguards and non-safeguards purposes.
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