Environmental influence in the corrosion parameters registered in a buried pilot nuclear waste container

Abstract

The El Cabril repository has a design life of 300-500 years and therefore, these structures should keep its integrity much longer than the back experience we have on reinforced concrete structures. This lack of record on structures older than 100-150 years makes a challenge the design of nuclear waste disposals and calls for more specific studies to try to anticipate the long term behavior. In order to study the real on-site aging of concrete, Enresa has undertaken a monitoring program in collaboration with IETcc and Geocisa by the installation of permanent sensors in a pilot nuclear waste container. These sensors were installed in 1995 for monitoring durability parameters. In the paper the evolution from 1995 of corrosion parameters obtained in a pilot container buried in real conditions in the repository of El-Carbril-Spain is presented. The non destructive tests (NDT) applied are based in electrochemical and mechanical measurements (corrosion rate, corrosion potential, electrical resistivity, concrete strains, oxygen availability). Relations between the climatic influence and the corrosion parameters are also presented. The results indicate that the temperature is a very relevant variable influencing the measurements. Some further analyses are given on the behavior with time of the corrosion.