Recent Advances in Corrosion Science Applicable To Disposal of High-Level Nuclear Waste

Abstract

High-level radioactive waste is accumulating at temporary storage locations around the world and will eventually be placed in deep geological repositories. The waste forms and containers will be constructed from glass, crystalline ceramic, and metallic materials, which will eventually come into contact with water, considering that the period of performance required to allow sufficient decay of dangerous radionuclides is on the order of 105–106 years. Corrosion of the containers and waste forms in the aqueous repository environment is therefore a concern. This Review describes the recent advances of the field of materials corrosion that are relevant to fundamental materials science issues associated with the long-term performance assessment and the design of materials with improved performance, where performance is defined as resistance to aqueous corrosion. Glass, crystalline ceramics, and metals are discussed separately, and the near-field interactions of these different material classes are also briefly addressed. Finally, recommendations for future directions of study are provided.

Investigation of silicic acid saturation and gel formation during ISG leaching: 180 days duration reaction at 90 °C

“…where ρ ISG is the density of ISG (2.5 g/cm 3 ). Nuclear glass corrosion is categorised into three stages, each indicated by a change in boron content in the solution: (i) initial phase, (ii) residual phase, and (iii) accelerated phase [1]. Figure 3 on day 3 in the GP system and on day 7 in the GC system shows that a higher rate of silica hydrolysis indicates a higher rate of early corrosion [3], which is the initial rate (r0).…”

“…Several related processes begin at the glass/water interface once the glass is exposed to water to achieve a new equilibrium or steady states, such as hydration, hydrolysis, dissolution, diffusion, and ion exchange [1,2].…”

“…Its surface generates secondary phases, lowering the glass alteration rate to a new phase termed residual rate [6,7,8,9]. The gel is a porous silica-rich hydrated surface layer formed by silica precipitating from the glass network [1,5,10]. Since the gel layer restricts diffusion exchanges between the glass surface and the surrounding aqueous, it inhibits thermodynamic equilibrium between the hydrated glass and the bulk solution [11].…”

Ab-Initio Simulation of Field Evaporation

“…Consequently, simulation of field evaporation has become an essential tool to detect and interpret artifacts and improve the quality of reconstructed data [4]. Physical modelling and simulation of field evaporation has implications beyond the field of atom probe tomography, * windl.1@osu.edu and can contribute to understanding the electrochemical behavior of surfaces during corrosion [5,6] and electrocatalysis [7].…”

Long-term interactive corrosion between International Simple Glass and stainless steel

“…Borosilicate glasses are a suitable candidate host for disposal of high-level waste (HLW) due to its durability, the capability to vitrify various compositions of radionuclides in the glass matrix without crystallization of the glass, and ease of processing [1][2][3][4] . The current plan in the U.S. and several other countries is to melt the glassforming materials with the radionuclides beyond the glass transition temperature and cast the melt into stainless steel (SS) canisters.…”