(Key Laboratory for Nuclear Materials and Safety Assessment of Chinese Academy of Science(CAS), Institute of Metal Research, CAS, Shenyang 110016, China)
More than 10 kinds of key testing equipments to simulate various corrosion failure modes of materials and in-situ testing technologies for material degradation test in high temperature pressurized water of nuclear power plant (NPP) were designed and developed independently for material degradation research and safety assessment. By strictly simulating the water chemistry in high temperature pressurized water various in-situ measurement technologies were innovated. The optical, spectral, acoustic emission, electrochemical, crack propagation, strain and other in-situ measurement techniques were established for materials corrosion in high temperature pressurized water of NPP under loading conditions. The transient electrochemical parameters by scratching repassivation in high temperature pressurized water to evaluate stress corrosion cracking susceptibility was invented, which shortened the evaluation time from several months to several days. The in-situ testing equipments, including corrosion electrochemistry, stress corrosion cracking, corrosion fatigue, fretting wear, crevice corrosion and irradiation assisted stress corrosion cracking etc, were developed to investigate corrosion behaviors of various materials in NPP. Accordingly, the testing standards were initiated. A large amount of testing data were obtained by these new techniques and equipments, which were used in the design, construction and operation of NPP in China. Finally, the development trend and future issues in this field are put forward.