The corrosion rate of copper in a test parcel at the Äspö Hard Rock Laboratory
2004 (English)In: Mater Res Soc Symp Proc, 2004, 489-494 p.Conference paper (Refereed)
Cylindrical copper electrodes have been installed in a test parcel at the Äspö Hard Rock Laboratory and real-time corrosion monitoring was initiated in May 2001. The test parcel was emplaced on October 29, 1999, and will be retrieved in 2004. The three electrodes, each of about 100 cm 2 surface area, are installed in bentonite block 36, where the temperature is about 24°C. The corrosion monitoring is performed with linear polarization resistance (LPR), harmonic distortion analysis (HDA) and electrochemical noise techniques. A value on the Stern-Geary coefficient is required to calculate the corrosion rate from the measured LPR data. A default value of 10.3 mV has been used, but an actual value can in fact be obtained from the HDA. The corrosion rate will be overestimated if the frequency of the voltage perturbation for the LPR measurements is not low enough. Electrode impedance measurements have been performed to verify this. Two and a half year after emplacement the recorded corrosion rate of copper in the above bentonite block amounts to about 2.2 μm per year (using a default value of 10.3 mV for the Stern-Geary coefficient and a 0.01 Hz voltage perturbation frequency). The actual corrosion rate is estimated to less than 0.7 μm per year (considering a measured Stern-Geary coefficient of 6.5 mV and the findings from the electrode impedance measurements).
Place, publisher, year, edition, pages
2004. 489-494 p.
, Materials Research Society Symposium Proceedings, ISSN 0272-9172 ; 807
Bentonite, Corrosion, Electric impedance, Electrochemistry, Electrodes, Harmonic distortion, Mineralogy, Perturbation techniques, Spectroscopic analysis, Corrosion rate, Harmonic distortion analysis (HDA), Linear polarization resistance (LPR), Real-time corrosion monitoring, Copper
IdentifiersURN: urn:nbn:se:kth:diva-157562ISI: 000225038400080ScopusID: 2-s2.0-12844286914OAI: oai:DiVA.org:kth-157562DiVA: diva2:770808
Scientific Basis for Nuclear Waste Management XXVII, 15-19 June 2003, Kalmar, Sweden
QC 201412112014-12-112014-12-112014-12-11Bibliographically approved