Technischer Bericht NTB 88-02
Zum Korrosionsverhalten von unlegiertem Stahl in Portlandzement
The production of hydrogen can cause problems in a repository for low- and intermediate-level waste. Since gas production is mainly due to the corrosion of carbon steel, it is important to have as reliable data as possible on the corrosion rate of steel in anaerobic cement.
A review of the literature shows that the corrosion current densities are in the range of 0.01 to 0.1 μA/cm2 (corresponding to corrosion rates between 0.1 and 1.2 μm/a). This implies hydrogen production rates between 0.022 and 0.22 mol/(m2 a).
Corrosion rates of this order of magnitude are technically irrelevant, with the result that there is very little interest in determining them accurately. Furthermore, their determination entails problems of measurement technique.
Given the current situation, it would appear somewhat risky to accept the lower value for hydrogen production as proven. Proposals are made for experiments which would reduce this element of uncertainty.