Qualification for Safeguards of the Sampling of UF6 using Alumina – “ABACC-Cristallini Method” – Progress Achieved

During the procedure currently used to sample material from process lines in uranium enrichment plants, the uranium hexafluoride (UF6) in gaseous phase is collected by desublimation inside a metal sampling cylinder cooled with liquid nitrogen or in a fluorothene P-10 tube type in certain facilities. A new method has been proposed [1], [2], [3] to collect the UF6 (gas) by adsorption in alumina (Al2O3) in the form of uranyl fluoride (UO2F2) (solid). This procedure receives the name “ABACC-Cristallini method” (A-C method). This paper describes the progress achieved in the technical certification process that ABACC is pursuing for qualification of the UF6 sampling A–C method for uranium isotopic determination. This method uses a fluorothene P-10 tube type containing alumina pellets that absorb and hydrolyze UF6 directly during the sampling. This method has been proven effective for ABACC safeguards purposes and potentially for IAEA safeguards as well. The activities being undertaken with the IAEA in the framework of the Brazilian and Argentinean Safeguards Support Programs with the coordination of ABACC represents a significant step towards the ultimate goal of using ABACC-Cristallini UF6 method in place of some or most of the traditional UF6 sampling for safeguards. The intercomparison results obtained from different laboratories will be the basis of the validation process to confirm that the new method can be used for routine safeguards application at the enrichment plants. It was previously verified that there is not a loss of