RBS AND NRA STUDIES IN ZR-ALLOY REACTOR MATERIALS

Rutherford backscattering and nuclear reaction analysis have been used to address a range of materials science problems associated with the Zr-alloy pressure tubes used in the Canadian CANDU (CANada Deuterium U ranium) nuclear reactors. pressure-tube corrosion in D2O, resulting in oxidation and deuterium ingress, is studied by measuring oxygen and d euterium concentration vs depth profiles. Hydrogen embrittlement, caus ed by D diffusion and formation of deuterided regions, is studied by D profiling. Irradiation creep of pressure tubes involves Zr self-diffu sion. Studies of substitutional diffusion of Hf in Zr-alloys using RBS have allowed diffusion coefficients to be measured and probable diffu sion mechanisms identified.