Characterization of the Hydrothermal Corrosion Behavior of Ceramics for Accident Tolerant Fuel Cladding

Recent Advances in Protective Coatings for Accident Tolerant Zr-Based Fuel Claddings

“…Among the indicated oxides, chromia is the only stable one that is slowly volatilized/sublimated during autoclave and LOCA conditions [19]. The sublimation rate of alumina and silica is not expected to be a problem at temperatures below 1300 • C; however, noticeable volatilization was shown after autoclave tests in a simulated PWR medium [164]. In addition, the protective coating, as well as the growing oxide layer, should have a dense microstructure to reduce the diffusion of oxygen and hydrogen (generated from oxidation reaction) along the grain boundaries of the coating.…”

Radiation Effect in Ti-Cr Multilayer-Coated Silicon Carbide under Silicon Ion Irradiation up to 3 dpa

“…Since SiC has a lower hydrogen generation rate and lower heat of reaction than Zr, the amount of hydrogen generated from fuel claddings by reaction with steam during severe accidents is expected to significantly decrease when SiC fuel cladding is used instead of conventional Zircaloy fuel cladding [3,4]. Therefore, the expectation for increased accident tolerance by applying SiC fuel cladding has led to the development of manufacturing and integration technologies [5][6][7][8][9][10][11][12][13][14][15][16], research on material behavior under normal operation and accident conditions [5][6][7][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31], and evaluation of safety and economic benefits [32].…”

“…In hydrothermal LWR coolant environments, the silicon in SiC undergoes oxidation and produces silica that readily dissolves in water where its concentration in the coolant builds up to the point of saturation, and beyond which the silica can deposit in the cold regions of the coolant loop [23]. Since the dissolved oxygen activity in water can greatly increase SiC recession, the amount of dissolved silica produced from SiC is likely to be larger in the coolant of a boiling water reactor (BWR) under the normal water chemistry (NWC) condition with a higher dissolved oxygen activity than in the coolant of a pressurized water reactor (PWR) [23][24][25][26][27]. Neutron irradiation increases hydrothermal corrosion rate [28].…”

“…Impurities including sintering additives and the crystalline orientation of SiC affect corrosion behavior in high temperature water [25,26,[34][35][36]. CVD SiC is expected to have a lower recession rate than SiC formed in other ways because of its higher purity.…”

“…CVD SiC is expected to have a lower recession rate than SiC formed in other ways because of its higher purity. As affairs now stand, it is difficult to suppress the silica dissolution from CVD SiC completely [26,31].…”