Study of Natural Analogues to Asses the Durability of Intermediate-Level Radioactive Waste Disposal Facilities

Reinforced Concrete (RC) is a major construction material used for many structures involved in the disposal of radioactive waste materials generated by the nuclear fuel cycle. These structures are required to function safely for long periods of time and the assessment of the corrosion magnitude is a key factor in predicting the service life of these structures. The present experience with RC is much shorter than the expected life of the fuel cycle-related facilities (i.e. about, 100 versus the required 300 or more years) then, additional input is required to ensure that these structures will continue to meet their design requirements throughout their operational life. This paper presents a study on the corrosion products formed on reinforced bars in some old RC structures found in Argentina. A study of this kind is necessary to improve knowledge on the long-term corrosion behavior of steels that could be used to build the intermediate-level radioactive waste disposal facilities. The type of corrosion products formed under two different environmental conditions was studied with different analytical methods like optical and electronically microscopes, energy dispersion X-Rays analysis, X-Rays diffraction analysis and Mössbauer spectroscopy. Moreover, a correlation between corrosion rates and environmental conditions was also analyzed.