Determination of hydrogen in leached UO(2) and Synroc
Elastic recoil detection analysis, ERDA, with 2 MeV He-ions was used to measure quantitatively hydration and hydrogen profiles in near-surface layers of UO(2) for spent nuclear fuel direct storage and for Synroc, a tailor-made titanate-based ceramic used to incorporate radioactive waste for safe, long-term underground storage. No hydrogen uptake was observed at temperatures below 100 C, but for higher leaching temperatures up to 200 C and for longer times, hydrogen profiles could be measured for both materials for the first time. For the specific case of UO(2), the combination of ERDA and of Rutherford backscattering analysis (combined with the channeling technique for UO(2)) enabled the measurement of the kinetics of UO(2) leaching in water at elevated temperatures and pressures: a first oxidation of UO(2) to U(3)O(7) occurs with layer thicknesses of a fraction of a micron, followed by further oxidation to UO(3) and simultaneous hydration as well as increases in layer thickness. Details of the technique and of the kinetics involved in hydration are presented.
Bibliographic Reference: Paper presented: Ion Beam Analysis Conference, Kingston, Ontario (CN), June 26-30, 1989
Availability: Available from (1) as Paper EN 34827 ORA
Record Number: 198911087 / Last updated on: 1994-12-01
Original language: en
Available languages: en