Experimental study on corrosion behaviour of carbon steel in buffer material, 1; Behavior of corrosion propagation based on the results of immersion tests for 10 years

Taniguchi, Naoki ; Kawasaki, Manabu*; Naito, Morimasa 

The deep underground environment where overpacks will be emplaced is expected to be anaerobic environment. It is necessary to understand the corrosion behavior of carbon steel in such environment for the assessment of corrosion lifetime of carbon steel overpacks. In this study, immersion tests of carbon steel were carried out in buffer material for 10 years duration in nitrogen atmosphere in which oxygen gas concentration was controlled to less than 1 ppm. Synthetic sea water and aqueous solution containing bicarbonate ion and chloride ion were selected as the test solution. The amount of corrosion of carbon steel was estimated from the weight loss of the specimen, and its change with time was investigated.