THE DEVELOPMENT AND APPLICATION OF STANDARDS FOR SAFEGUARDS WITHIN THE UK SUPPORT PROGRAMME TO THE IAEA

Under the auspices of the UK Support Programme to the IAEA, AEA Technology, Nuclear Science, Harwell Laboratory prepares customised standards for application by the IAEA. Current developments include the preparation of actinide glass standards, containing uranium and plutonium of compositions similar to those found in reprocessing plant solutions. These standards are intended to provide a stable, routine quality control of measurements by k-edge densitometry without rigorous traceability. Also for quality control, uranium particle standards have been prepared to check the performance of analytical procedures and equipment used in environmental safeguards. Working standards are under preparation for use in the measurement of uranium and plutonium in reprocessing plant solution by isotope dilution mass spectrometry. These standards, in the form of U/Pu alloy spikes, have been prepared from certified reference materials on the basis of make up values. Finally, plutonium isotopic standards are under preparation for the calibration of mass spectrometers and alpha spectrometers. These standards are being prepared on a gravimetric basis with the aim of producing certified isotopic standards traceable to SI units. The development of all of these materials will be described and the appropriate traceability and application, as quality control materials, working standards or reference materials, will be discussed.