Corrosion of Glass Used for Radioactive Waste Disposal Influenced by Ankerite

Abstract

In this study, the vitrified High-Level Radioactive Waste (HLW) disposal was simulated using a simplified version of the French R7T7 reference glass, called International Simple Glass (ISG). Test for nuclear waste form (MCC-1) was assembled for (3-90 days) using coupon samples of ISG and powdered Ankerite. Set up systems were conducted using ultrapure water at 90 °C and initial pH 6.3. The chemical effect of Ankerite on the ISG coupon was seen via Mg-Si precipitation, but the hydrated layer on the ISG was seen clogged by the Ankerite's dissolution products which lowered the ISG corrosion rate comparing to the ISG reference system. When the values expressed as mass glass dissolved per unit area, the higher sodium releases and the higher corrosion rates have been attained based on sodium release, which suggests sodium as representative of the ISG at the lower surface area to volume.