History of corrosion studies on container materials for the final disposal of VHLW and SF conducted in Belgium

Abstract

In Belgium, an extensive corrosion program on a wide range of metals has been studied as candidate container material, which is considered in the geological disposal concept of high‐level radioactive waste or spent fuel. This paper presents an overview of the corrosion studies initiated by SCK CEN more than 40 years ago. The experiments conducted in these studies were conceived based on early disposal designs, that is, designs in which the radioactive waste was to be enclosed in a metallic overpack that would be directly emplaced in an argillaceous environment. A step‐wise approach was adopted consisting of laboratory screening studies, detailed studies, and demonstration tests. The screening studies included accelerated tests, conducted in a surface laboratory, and exposure tests carried out either in autoclaves or in the field in a surface clay quarry. The detailed studies involved both in situ and laboratory experiments. Gradually, the emphasis shifted from basic research to large‐scale integrated demonstration experiments enabling the simultaneous study of different parameters and/or processes and their coupling.