Development Of Pu/Am-241 Age Dating Capabilities For Analysis Of Nuclear Materials For Safeguards

The age of the origin of pure plutonium materials is an important piece of information, as it can be closely examined in the verification of a State’s declared nuclear material and activities, and in the detection of undeclared nuclear material and activities. Therefore there is an obvious need to develop and validate this analytical capability to determine the age of origin, to be able to provide independent information for making credible safeguards conclusions. Age dating methodology for analysis of nuclear material samples containing plutonium, using the Pu-241/Am-241 radio-chronometer will be described, comparing performance of gamma spectrometry with isotope dilution mass spectrometry analysis using different Am-243 spike materials and thermal ionization mass spectrometry for isotope ratio measurements. Several available reference materials with known production dates have been used for analysis and the results have been compared with results obtained by external expert laboratories and results available from the literature.