Hostname: page-component-76fb5796d-zzh7m Total loading time: 0 Render date: 2024-04-26T18:10:02.847Z Has data issue: false hasContentIssue false

Corrosion Tests of Zircaloy Hull Waste to Confirm Applicability of Corrosion Model and to Evaluate Influence Factors on Corrosion Rate under Geological Disposal Conditions

Published online by Cambridge University Press:  01 July 2014

Osamu Kato
Affiliation:
Kobe Steel, LTD., JAPAN
Hiromi Tanabe
Affiliation:
Radioactive Waste Management Funding and Research Center, JAPAN
Tomofumi Sakuragi
Affiliation:
Radioactive Waste Management Funding and Research Center, JAPAN
Tsutomu Nishimura
Affiliation:
Kobe Steel, LTD., JAPAN
Tsuyoshi Tateishi
Affiliation:
Kobelco Research Institute Inc., JAPAN
Get access

Abstract

Corrosion behavior is a key issue in the assessment of disposal performance for activated waste such as spent fuel assemblies (i.e., hulls and end-pieces) because corrosion is expected to initiate radionuclide (e.g., C-14) leaching from such waste. Because the anticipated corrosion rate is extremely low, understanding and modeling Zircaloy (Zry) corrosion behavior under geological disposal conditions is important in predicting very long-term corrosion. Corrosion models applicable in the higher temperature ranges of nuclear reactors have been proposed based on considerable testing in the 523−633 K temperature range.

In this study, corrosion tests were carried out to confirm the applicability of such existing models to the low temperature range of geological disposal, and to examine the influence of material, environmental, and other factors on corrosion rates under geological disposal conditions. A characterization analysis of the generated oxide film was also performed.

To confirm applicability, the corrosion rate of Zry-4 in pure water with a temperature change from 303 K to 433 K was obtained using a hydrogen measuring technique, giving a corrosion rate for 180 days of 8 × 10-3 μm/y at 303 K.

To investigate the influence of various factors, corrosion tests were carried out. The corrosion rates for Zry-2 and Zry-4 were almost same, and increased with a temperature increase from 303 K to 353 K. The influence of pH (12.5) compared with pure water was about 1.4 at 180 days at 303 K.

Type
Articles
Copyright
Copyright © Materials Research Society 2014 

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

Tanabe, H. et al. ., 2013, “Long Term Corrosion of Zircaloy Hull Waste under Geological Disposal Conditions: Corrosion Correlations, Factors Influencing Corrosion, Corrosion Test Data, and Preliminary EvaluationMat. Res. Soc. Symp. Proc. Scientific Basis for Nuclear Waste Management XXXVII.Google Scholar
Sakuragi, T. et al. ., 2012, “Corrosion Rates of Zircaloy-4 by Hydrogen Measurement under High pH, Low Oxygen, and Low Temperature Conditions,” Mater. Res. Soc. Symp. Proc. 1475, p. 311.CrossRefGoogle Scholar
Honda, A. et al. ., 1999, Japan Patent 2912365.Google Scholar
Yamaguchi, T. et al. ., 1999, “Study on Chemical Forms and Migration Behavior of Radionuclides in Hull Waste”, Proceedings of ICEM 99, September, Nagoya, Japan.Google Scholar
IAEA, 1998, “Waterside corrosion of zirconium alloys in nuclear power plants”, IAEA-TECDOC-, p996 Google Scholar
Hagi, S. et al. ., 2005, “Introduction to Nuclear Fuel Engineering; Focused on LWR Fuel - (8) LWR Fuel Fabrication, Nuclear and Thermal-Hydronic Design”, J. Nucl. Sci. Technol. Vol. 47, No. 1.Google Scholar
Garzarolli, F. et al. , 1989, “Microstructure and Corrosion Studies for Optimized PWR and BWR Zircaloy Cladding”, Zirconium in the Nuclear Industry, ASTM STP 1023.CrossRefGoogle Scholar
Japan Nuclear Energy Safety Organization Report, 2012.Google Scholar
Takeda, et al. , 1996, “Effect of Oxide Film Structure on Resistance to Uniform Corrosion of Zircaloy-4”, J. Japan Inst. Met. Mater. vol. 60, No. 9.Google Scholar