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

Stephane Gin,Xiaolei Guo,Gerald S Frankel

doi:10.1038/s41529-020-00140-7

Stephane Gin, Xiaolei Guo + Show 1 more

Open Access

https://doi.org/10.1038/s41529-020-00140-7

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Journal: npj Materials Degradation	Publication Date: Nov 11, 2020
Citations: 20	License type: open-access

Affiliation: The Ohio State University

Abstract

This review covers the corrosion interactions between different materials that are relevant to the disposal of high-level nuclear waste, in particular the waste forms and containers. The materials of interest are borosilicate glass, crystalline ceramics, metal alloys, and any corrosion products that might form. The available data show that these interactions depend on the structure, chemistry, thermodynamic history, and proximity of the materials in contact, as well as the environmental attributes, such as temperature, solution chemistry, and radiation. Several key mechanisms that govern these interactions are highlighted. Scientific gaps and open questions are summarized and discussed.

Highlights

In many countries, the current plan for the disposal of high level waste (HLW) includes mixing the radionuclides with aluminoborosilicate glass and heating them to a temperature exceeding the glass melt temperature, which is typically over 1000 °C1–3
The corrosion of glass or crystalline ceramic waste forms can be influenced by close contact with a broad spectrum of materials
These interactions cause nearfield changes of the solution chemistry, which impact the corrosion of other materials present nearby

Summary

INTRODUCTION

The current plan for the disposal of high level waste (HLW) includes mixing the radionuclides with aluminoborosilicate glass and heating them to a temperature exceeding the glass melt temperature, which is typically over 1000 °C1–3. The French Cigéo program describes a deep geological repository that will be built at the Meuse/Haute-Marne site, which is within a saturated zone under the water table and 500 m below the surface[11]. In this program, the HLW is mixed with glass frit, molten at 1050 °C in a hot crucible melter and poured into SS (AISI 309S) canisters. A micro-tunnel casing made from a different CS (API 5L X65 grade) with a wall thickness of 2.5 cm will be applied surrounding the CS overpack and emplaced in the drift (Fig. 2b)[12] These waste packages will subsequently be embedded in filling materials (cement and bentonite mixture) with a wall thickness of about.

Guo et al 2

SUMMARY AND PERSPECTIVES