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The electrochemical behavior of La2O3 was investigated in LiF-NaF-KF (FLiNaK, 46.5-11.5-42.0 mol %) eutectic at 700°C. In the electrochemical tests, two kinds of working electrodes, i.e., tungsten ...

Alloying additions are introduced into U-Zr fuel in order to bind lanthanides (e.g., cerium) and prevent their migration to the fuel-cladding interface. Antimony (Sb) is being investigated as a can...

The aluminum (Al) alloy corrosion and precipitation tests were carried out in a high-temperature flow loop under different hypothesized post-LOCA chemistry conditions. The effect of the temperature, pH, flow rate and presence of other potential ions on Al corrosion was studied. The Al hydroxide phase transition from less-stable forms to thermodynamically stable forms during isothermal stage preferentially occurred in NaTB-buffered solution. The presence of Zn in solution could effectively inhibit Al release. The solution pH has a strong influence on Al corrosion and the volume of formed precipitate. A kinetic equation was developed to describe Al loss as a function of mass transfer coefficient and solution pH, the effect of OH- concentration on Al corrosion was more pronounced than the rate of mass transfer.

The impurity-driven corrosion behavior of HAYNES® 230® alloy in the molten KCl-MgCl2-NaCl salt was studied at 800 °C for 100 h with different salt purity conditions. It was found that HAYNES® 230® alloy exhibited better corrosion resistance in the salt with lower impurities. Furthermore, the corrosion (non-immersion) due to molten salt vapors was more severe at higher temperature. The attack was localized and driven by outward diffusion of chromium through the grain boundaries. The presence of Mg in its metal form in the salt resulted in an even higher mass-loss in HAYNES® 230® alloy due to Mg-Ni interaction.

FeCrSi alloys have been proposed as alternatives to FeCrAl alloys for accident-tolerant fuel cladding in light water reactors. Experiments on the oxidation resistance of three Fe-Cr-2Si alloys in high-temperature steam, with 12, 16, and 20 wt. % Cr, show that ≥16 % Cr is sufficient to form a thin, passivating, binary oxide layer. At 1200 °C, only Cr2O3 and SiO2 form on Fe16Cr2Si and Fe20Cr2Si, while additional ternary Fe oxides form on Fe12Cr2Si. Decohesion and spalling of oxide were observed on Fe-Cr-Si alloys exposed to steam at 900 °C and above. Fe20Cr2Si exhibits the best oxidation resistance of the three in high-temperature steam.

The fundamental kinetic parameters of corrosion product ions (Fe, Ni and Cr ions) are of significant importance to understand the corrosion mechanisms of the structural materials in the molten salts. In the present study, the fundamental data of Fe2+, Ni2+, Cr2+ and Cr3+ (diffusion coefficient D, exchange current density i 0, charge transfer coefficient α, limiting current density i L and standard rate constant k 0) were measured at different concentrations (1.53 × 10−6−7.48 × 10−4 mol cm−3) and temperatures (600 °C–800 °C). The values of D are independent of concentrations and follow Arrhenius law with temperature, which descend in the order of D C r 2 + > D F e 2 + > D C r 3 + > D N i 2 + , with values ranging from 0.94 × 10−5 to 3.31 × 10−5 cm2 s−1. Both i 0 and k 0 depend on the temperatures, which also follow Arrhenius law. The values of the estimated k 0 descend in the order of k C r 2 + 0 > k F e 2 + 0 > k N i 2 + 0 > k C r 3 + 0 , which range from 1.88 × 10−5 to 9.06 × 10−4 cm s−1.

Magnetic nanomaterials have received tremendous attention in the past years due to their unique magnetic responsiveness and corresponding wide applications in many fields. Herein this paper presents several methods to prepare monodisperse magnetic microspheres through a facile hydrothermal technique. The added surfactants were sodium dodecyl benzene sulfonate (SDBS), poly(vinylpyrrolidone) (PVP), trisodium citrate (TSC), and polyethylene glycol (PEG). Transmission electron microscopy (TEM) reveals the monodispersed magnetite (Fe3O4) microspheres with narrow size distribution can be obtained using SDBS as the surfactant. In addition, Fe3O4@SiO2 was prepared by modified Stober methods resulting in the microspheres with more smooth surface and better dispersion. Keywords-magnetic nanomaterials; preparation; capping