This work is focused on the evaluation of the influence of galvanic couples between materials for radioactive waste canisters. The materials considered are carbon steel, stainless steel, copper, and titanium alloy. All materials were tested by means of potentiodynamic curves and zero resistance ammetry. The specific resistivity of compacted bentonite was estimated in a special cell. These results were used for simple one‐dimensional numeric simulation of a galvanic couple. The conductivity of saturated compacted bentonite is excellent and the reach of galvanic corrosion is high. The influence on the corrosion rate of anodic carbon steel is negligible, but it allows for the employment of a large area of cathodic materials, which could be susceptible to hydrogen embrittlement.
The Czech Republic has a well-developed nuclear programme with two nuclear power plants currently in operation and three operational near-surface repositories serving for the disposal of institutional and operational low-and intermediate-level waste. Spent nuclear fuel will be disposed of in a deep geological repository to be constructed in crystalline or metamorphic rock approximately 500 m below the surface. Czech Ca-Mg bentonites will be used as the buffer and backfilling material. Steel-based materials are currently considered as the reference metallic materials in the Czech disposal canister concept. The preferred design is based on a doublewalled canister with an inner shell of stainless steel and an outer shell of carbon-steel. Both parts of the canister must provide mechanical stability; the wall of the carbon-steel canister will be strengthened for corrosion-resistance purposes. The presented work focuses on canister design as confirmed by means of mechanical, thermal and criticality calculations and a detailed experimental corrosion plan.
The goal of the study was to compare corrosion performance of copper in different bentonite slurries. Copper coil samples were exposed in a slurries of bentonites BaM, Rokle, B75, G2M, Voltex, Sabenil. The test was carried out under anaerobic conditions in glovebox at laboratory temperature for duration of one to four months. Samples were evaluated by means of X-ray diffraction and mass loss. Liquid parts of slurries were analysed by ion chromatography and pH meter. The resistance of copper in all studied bentonites was very high. Corrosion rates were in order of tenths of micrometers per year. No trend between pore solution composition and corrosion rate or composition of corrosion products was observed.
This study is focused on an influence of heat transfer on corrosion behaviour of structural materials for radioactive waste canister in synthetic bentonite pore water and bentonite suspension. Experiments were carried out in special cell on cylindrical sample of carbon steel, copper, titanium-palladium alloy and two types of stainless steel. Samples were subjected in synthetic bentonite pore water to sixty-fold higher heat transfer compared to real repository, and approximately thirty-fold higher in bentonite suspension. Corrosion behaviour was observed in two-electrode setup with platinum wire as counter electrode by means of electrochemical impedance spectroscopy. Results showed negligible effect of heat transfer compared to surface temperature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.