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Estimating the Mass of UO3 Powder in a Container Using MCNP-PoliMi Simulations of NMIS Measurements.

DE2008931145

Publication Date	2008
Personal Author	Grogan, B. R.
Page Count	52
Abstract	The Nuclear Materials Identification System (NMIS) uses fast neutrons to conduct non-intrusive scans of both fissile and non-fissile materials. By time-tagging the source neutrons, the NMIS processor can measure the time of flight of these neutrons through the target of the scan and into detectors on the opposite side. With a monoenergetic neutron source, such as a DT generator, these time-of-flight measurements can approximately determine the number of neutrons that travel through the target uncollided. By comparing the results of a scan on an empty container and one made on a container with unknown materials inside, the NMIS processor can subtract the container and determine the configuration of materials inside. Using multiple small detectors, and many horizontal and vertical samples, the NMIS system can produce a picture of the object being scanned, known as a neutron radiograph. With this radiograph, it is thought that other characteristics of the scanned material can be inferred. In this thesis, the material being scanned consists of highly enriched uranium trioxide (UO(sub 3)) powder. Using the results of the time-of-flight measurements from two reference scans, a container with an unknown configuration was scanned and the mass of the UO(sub 3) powder inside was estimated. The MCNP-PoliMi computer code was used to simulate these scans.
Keywords	Uranium trioxide Containers Neutron sources Neutrons Highly enriched uranium Fissile materials Algorithms Computer codes Configuration Fast neutrons Geometry Identification systems Targets
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Oak Ridge National Lab., TN.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200825
Contract Number	DE-AC05-00OR22725

Estimating the Mass of UO3 Powder in a Container Using MCNP-PoliMi Simulations of NMIS Measurements.

Estimating the Mass of UO3 Powder in a Container Using MCNP-PoliMi Simulations of NMIS Measurements.
DE2008931145

Publication Date	2008
Personal Author	Grogan, B. R.
Page Count	52
Abstract	The Nuclear Materials Identification System (NMIS) uses fast neutrons to conduct non-intrusive scans of both fissile and non-fissile materials. By time-tagging the source neutrons, the NMIS processor can measure the time of flight of these neutrons through the target of the scan and into detectors on the opposite side. With a monoenergetic neutron source, such as a DT generator, these time-of-flight measurements can approximately determine the number of neutrons that travel through the target uncollided. By comparing the results of a scan on an empty container and one made on a container with unknown materials inside, the NMIS processor can subtract the container and determine the configuration of materials inside. Using multiple small detectors, and many horizontal and vertical samples, the NMIS system can produce a picture of the object being scanned, known as a neutron radiograph. With this radiograph, it is thought that other characteristics of the scanned material can be inferred. In this thesis, the material being scanned consists of highly enriched uranium trioxide (UO(sub 3)) powder. Using the results of the time-of-flight measurements from two reference scans, a container with an unknown configuration was scanned and the mass of the UO(sub 3) powder inside was estimated. The MCNP-PoliMi computer code was used to simulate these scans.
Keywords	Uranium trioxide Containers Neutron sources Neutrons Highly enriched uranium Fissile materials Algorithms Computer codes Configuration Fast neutrons Geometry Identification systems Targets
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Oak Ridge National Lab., TN.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200825
Contract Number	DE-AC05-00OR22725