STREAMLINED REPROCESSING IMPUT VERIFICATION MEASUREMENTS IN THE EURATOM ON-SITE LABORATORY AT LA HAGUE

Aliquots taken from input accountancy tanks represent the largest contingent of samples to be analyzed for Safeguards purposes in the forthcoming Euratom On-Site Laboratory ('Laboratiore sur Site' =LSS) at La Hague. Established techniques such as Hybrid K-Edge Densitometry (HKED) and Isotope Dilution Mass Spectrometry (IDMS) are utilised, but have been further streamlined for respective application in order to cope efficiently with the measurement requirements and boundary operating conditions in the LSS. The streamlined HKED measurements in the LSS will offer a higher degree of automation and operational simplicity. This improvement was achieved with a re-designed instrument layout incorporating a sample changer, and with a modified measurement procedure allowing direct measurements on the posted input samples. Developmental efforts for streamlining the IDMS analysis to the given boundary conditions in the LSS were mainly required on the sample treatment side. Fully robotized sample treatment procedures including improved U/Pu/Fission product separation, alpha spectrometry of the U and Pu fraction, and filament preparation for mass spectrometry were set up to automate the sample preparation for IDMS to a high degree. The paper addresses the technical and operational aspects of the recent developments.