Use of nanoprobes to identify iron-silicates in a glass/iron/argillite system in deep geological disposal

摘要

The understanding of glass alteration mechanisms in contact with iron is a major issue to study the long-term behavior of radioactive waste package in repository conditions. A glass/iron/claystone system was altered in contact with COx water at 50 degrees C for 4.5 years in Andra's underground research laboratory in Sure, France. Multiscale and multitechnical (SEM-EDX, mu Raman, STXM and TEM) characterization of the system revealed the presence of nanometric crystalline Fe(III)-rich smectite, assimilated to nontronite, in the glass alteration layer and in corrosion products. These phyllosilicates were identified by STXM using a comparative approach with a database of reference spectra obtained on iron-silicate.