Passivity degradation of nuclear materials in reduced sulfur environments: A review

This paper reviews sulfur-induced passivity degradation of nuclear materials with emphasis on steam generator(SG)alloys. The state of arts on this topic concerning thermodynamic calculation and experimental data has been reviewed. Thermodynamic calculation results indicate that the distribution of sulfur species strongly depends on pH and temperature. Experimental data show that solution pH, temperature and solution chemistries can significantly affect the electrochemical behaviors of SG materials and the underlying degradation mechanisms. Some issues when conducting corrosion tests at high temperature should be paid attention to, such as the dissolution of the autoclave, which may affect the facticity of the experimental results.