Nuclear Security Science and Policy (NSSPI) Graduate Assistant Researchers, Braden Goddard and Chris Ryan, traveled to the European Commission Joint Research Center (JRC) in Ispra, Italy from December 4 through December 11, 2010, to perform neutron measurements in support of Goddard’s Ph.D. research.
The objective of the measurements was to detect neutrons in coincidence using an International Atomic Energy Association (IAEA) approved Active Well Coincidence Counter (AWCC). The material measured consisted of uranium, plutonium, and mixed-oxide in different isotopic concentrations. The measurements were also done in three different detection modes: 1) passive detection with spontaneous fission neutrons, 2) active interrogation using neutrons from an americium-lithium (α, n) source, and 3) active interrogation with neutrons from an americium-beryllium (α, n) source. The goal of the research is to create a non-destructive method for quantitatively determining the isotopic masses of uranium, neptunium, plutonium, and americium in an oxide mixture. Although current actinide mixtures of this type are very rare, emerging reprocessing schemes such as the Uranium Extraction Plus-3A (UREX+3a) process will be capable of producing materials with many different actinides.
NSSPI would like to thank the JRC Performance Laboratory (PERLA) for allowing the use of their facility and Dr. Paolo Peerani for assisting with the measurements and providing a valuable critique of the research.