Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-25T18:42:12.879Z Has data issue: false hasContentIssue false

The Corrosion Rate of Copper in a Test Parcel at the Äspö Hard Rock Laboratory

Published online by Cambridge University Press:  01 February 2011

Bo Rosborg
Affiliation:
Rosborg Consulting, Östra Villavägen 3, SE - 611 36 Nyköping, Sweden. KTH, Div. of Corrosion Science, Drottning Kristinas väg 51, SE - 100 44 Stockholm, Sweden.
David Eden
Affiliation:
InterCorr International, 14503 Bammel-North Houston, Suite 300, Houston, TX 77014, USA.
Ola Karnland
Affiliation:
Clay Technology AB, Ideon Research Center, SE - 223 70 Lund, Sweden.
Jinshan Pan
Affiliation:
KTH, Div. of Corrosion Science, Drottning Kristinas väg 51, SE - 100 44 Stockholm, Sweden.
Lars Werme
Affiliation:
Svensk Kärnbränslehantering AB, Box 5864, SE - 102 40 Stockholm, Sweden.
Get access

Abstract

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 cm2 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).

Type
Research Article
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. “SR 97 Waste, Repository Design and Sites”, Swedish Nuclear Fuel and Waste Management Co, Stockholm, Report No. TR-99–08, 1999.Google Scholar
2. Werme, L., “Design Premises for Canister for Spent Nuclear Fuel”, Swedish Nuclear Fuel and Waste Management Co, Report No. TR-98–08, 1998.Google Scholar
3. Karnland, O. (private communication).Google Scholar
4. Karnland, O. et al, “Long Term Test of Buffer Material - Final Report on the Pilot Parcels”, Swedish Nuclear Fuel and Waste Management Co, Report No. TR-00–22, 2000.Google Scholar
5. Rosborg, B., Karnland, O., Quirk, G., and Werme, L., “Measurements of Copper Corrosion in the LOT Project at the Äspö Hard Rock Laboratory”, in Proc. Inter. Workshop Prediction of Long Term Corrosion Behaviour in Nuclear Waste Systems, November 26–29, 2001, Cadarache, France. To be published in an EFC volume.Google Scholar
6. Stern, M. and Geary, A. L., J. Electrochem. Soc. 104 (1), 5663 (1957).Google Scholar
7. Brennenstuhl, A. (private communication).Google Scholar
8. Darowicki, K. and Majewska, J., Corros. Rev. 17 (5–6), 383399 (1999).Google Scholar
9. Electrochemical Noise Measurement for Corrosion Applications, edited by Kearns, J. R. et al (ASTM STP 1277, American Society for Testing and Materials, West Conshohocken, PA, 1996).Google Scholar
10. Eden, D. A., “Electrochemical Noise - The First Two Octaves”, CORROSION/98, Paper No. 386, NACE, Houston, TX (1998).Google Scholar
11. Rosborg, B. and Pan, J. (unpublished).Google Scholar
12. Rosborg, B., Karnland, O., and Werme, L., “The corrosion resistance of pure copper in repository environments”, in Proc. Tenth Inter. Conf. on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, August 5–9, 2001, Lake Tahoe, Nevada.Google Scholar
13. Rosborg, B. (unpublished).Google Scholar