Near-field corrosion interactions between glass and corrosion resistant alloys

Abstract

This study explores the corrosion interactions between model nuclear waste glass materials and corrosion resistant alloys, under accelerated conditions that simulate the near field of a nuclear waste repository. The interactions between the corrosion of stainless steel (SS) 316, alloy G30, or alloy 625, and international simple glass or soda-lime silica glass are systematically studied. The dissimilar materials were exposed in close proximity to each other in different electrolytes at 90°C. After exposure, the glass surface exposed near metals showed different regimes of corrosion, with distinct surface morphologies and chemistries that were likely affected by the local environment created by the localized corrosion of metals. Surface and solution analyses showed that the corrosion rate of glass was enhanced by the presence of metals. Infrared spectroscopy data suggested the local build-up of stresses in the contact area of glass, which may lead to the mechanical instability of the glass alteration layer. On the other hand, the effect of glass on metal corrosion is strongly dependent on the leaching solution. In electrolytes containing abundant aggressive anions such as Cl − , glass seems to suppress the localized corrosion of SS by the precipitation of a Si-rich surface film that protects the SS substrate from solutions. However, in less aggressive electrolytes, the corrosion rate of SS was increased by the presence of glass corrosion products. Overall, our study showed that the hidden and localized damage on glass in contact with metals may enhance the release rate of glass components compared to typical uniform glass corrosion.

Corrosion of ISG by Mg-Si precipitation in presence of Ankerite

“…Iron (Fe) concentrations in the ISG systems were lower than the detection limit in the present experiment, which might be owing to its rapid integration into the Si network during the first corrosion phase [16]. Magnesium solubility was observed in various systems.…”

“…That balance leads to silicate saturation in a solution in which the ultimate silicic acid saturation (H 4 SiO 4 ) occurs. Finally, if the interventions by iron minerals i.e., Ankerite or other geological factors are not carried out [15][16][17][18][19][20][21], the corrosion rate of HLW glass should reach a steady state.…”

Corrosion interactions between stainless steel and lead vanado-iodoapatite nuclear waste form part I

“…Since the nature of the filling materials is not clearly defined at this point, this study only considers the interface between the canister and ceramics. We have recently reported the potential corrosion interactions between SS and other waste forms in a corrosive environment 9,10 . Synergistic interactions were found between the SS crevice corrosion and the corrosion of Cr-bearing hollandite ceramic waste forms.…”

Review of corrosion interactions between different materials relevant to disposal of high-level nuclear waste

“…Extensive studies have shown that these Si-bearing minerals can enhance glass corrosion by disrupting the steadystate corrosion of glass and triggering the Stage III glass corrosion regime 58 . While the corrosion of glass was clearly enhanced by SS in both DI water and NaCl solution, the effect of glass on the corrosion of SS depended on the solution chemistry 57 . In NaCl solution, the glass corrosion products, primarily silicates, inhibited the corrosion of SS, owing to the suppression of the SS passive film breakdown.…”

“…In recent studies, a mechanism of nearfield interaction based on metal crevice corrosion was disclosed by Guo et al, as schematically illustrated in Fig. 9 30,45,57 . The authors corroded international simple glass (ISG) or soda lime silica glass (SLSG) in close proximity to SS316, Alloy 625, or Alloy G30 in 0.6 M NaCl solution or DI water at 90°C for 14 or 30 days.…”