A combined calorimetry, neutron coincidence counting and gamma spectrometry system (CANEGA) for enhanced plutonium mass and isotopic assay

A measurement approach for enhanced plutonium assay combining three passive non-destructive measurement techniques - calorimetry, neutron coincidence counting and gamma spectrometry (CANEGA) - has been designed and evaluated. The combination of the measured quantities obtained from the three techniques not only leads to an improvement of the plutonium assay through redundant and complementary measurement information, but also provides a more complete fingerprint for any plutonium-bearing sample under assay. Further, the combined measurement information allows one to derive a more reliable estimate for the 242Pu isotope abundance not directly measurable by gamma spectrometry. A conceptual feasibility and design study for a transportable CANEGA prototype instrument has been carried out with the aim of defining the most promising and advantageous instrument configuration. (author)