Izvestiya vuzov. Yadernaya Energetika

The peer-reviewed scientific and technology journal. ISSN: 0204-3327

Galvanic corrosion of zirconnium alloys in water coolant

7/09/2020 2020 - #02 Nuclear materials

Melehovets A.Y. Pyshin I.V.

DOI: https://doi.org/10.26583/npe.2020.2.05

UDC: 621.039.546

One of the factors limiting the operation of a nuclear reactor is degradation of the core structural materials and the fuel claddings made of zirconium alloys in water coolant. Thus, it is typical of BWR reactors to have the Zircaloy-2 fuel channel cladding surface corrosion accelerated locally near the stainless steel control blade (shadow corrosion). A common explanation is that galvanic effect is responsible for the phenomenon. The presented mathematical model shows that dissimilar metals in the core (zirconium alloy and steel) form a corrosive galvanic element which results in accelerated local corrosion of the zirconium alloy. In VVER reactors, due to a great distance between the core structural elements with different electrochemical potentials, the galvanic corrosion process is more uniform over the corroding element’s large area, so no shadow corrosion occurs. The contribution of galvanic effects to the overall corrosion process can be however substantial.

References

  1. Reshetnikov F.G., Bibilashvili Yu.K., Golovnin I.S. Development, production and operation of fuel elements for energy reactors. Мoscow. Energoatomizdat Publ., 1995. 317 p. (in Russian).
  2. Bibilashvili Yu.K., Velikhanov A.G., Ioltukhovsky A.G. Experience in operating fuel elements in VVER reactors, including contingency analysis. VANT. Ser. FRP and RM. 1997, v. 1-2, pp. 84-105 (in Russian).
  3. The Safety of WWER and RBMK Nuclear Power Plants. Review. IAEA TECDOC-773. IAEA. Vienna, 1994.
  4. Review of Fuel Failures in Water Cooled Reactors, IAEA Report. Techical Report Ser. No. 388. IAEA, Vienna. 1998.
  5. Strasser A. World experience in the operation of fuel elements of light-water reactors. Yadernye Tekhnologii za Rubezhom. 1986, no. 9, p. 28 (in Russian).
  6. Chatelain A. et al. Enhanced Corrosion of Zirconium-Base Alloys in Proximity to Other Metals: The «Shadow Effect». Proc. of the ANS International Topical Meeting on Light Water Reactor Fuel Performance. Park City, Utah, April 10-13, 2000.
  7. Chen J.S.F., Adamson R.B. Observations of Shadow Phenomena on Zirconium Alloys. In: Proc. of the International Topical Meeting on LWR Fuel Performance. West PalmBeach, USA. 1994, pp. 309-317.
  8. Fukuya K., Echigoya H., Hattori Y., Kobayashi K., Kobayashi K., Sasaki T. BWR fuel channel performance and localized corrosion at high burnups. In: Proc. of the International Topical Meeting on LWR Fuel Performance. ANS, West PalmBeach, Florida. 1994, pp. 580-586.
  9. Mahmood S.T., Cantonwine P.E., Lin Y.P., Crawford D.C. Shadow Corrosion-Induced Bow Of Zircaloy-2 Channels. Proc. of the XVIth Intern. Symposium on Zirconium in the Nuclear Industry. Chengdu, China. 2010. DOI: https://doi.org/10.1520/STP152920120038 .
  10. Lysell, G., Nystrand, A. and Ullberg, M. Shadow Corrosion Mechanism of Zircaloy. Journal of ASTM International. 2005, v. 2, no. 6, pp. 1-17. DOI: https://doi.org/10.1520/JAI12374 .

  11. Barberis P., Skocic M., Kaczorowski D., Perche D., Wouters Y., Nowotka K. Shadow corrosion: Experiments and modeling. Journal of Nuclear Materials. 2019, v. 523, pp. 310-319. DOI: https://doi.org/10.1016/j.jnucmat.2019.06.001 .

  12. Trowse F.W., Sumerling R., Garlick A. Nodular Corrosion of Zry-2 and Some Other Zirconium Alloys in Steam Generating Heavy Water Reactors and Related Environments. In: Zirconium in the Nuclear Industry, ASTM-STP 633. 1977, pp. 236-257. DOI: https://doi.org/10.1520/ STP35574S .

  13. Adamson R., Cox B., Rudling P., Strasser A., Wikmark G. The Annual Review of Zirconium Alloy Technology for 2000. ZIRAT5 Annual Report. Molnlycke. ANT International, 2001.

  14. Buttin P., Malki B., Barberis P., Baroux B. Numerical analysis of the galvanic coupling in the shadow corrosion of zirconium alloy. Journal of Nuclear Materials. 2012, v. 420, pp. 591-596. DOI: https://doi.org/10.1016/j.jnucmat.2011.11.002 .

  15. Greek A. The first hydrofoil ships in the XXI-st century are being built in Russia. Popular Mechanics. 2017, March, pp. 68-73.

  16. Adamson R., Garzarolli F., Cox B., Strasser A. and Rudling P. Corrosion Mechanisms in Zirconium Alloys. ZIRAT12/IZNA7 Special Topics Report, ANT International, Molnlycke, Sweden, 20072008.

  17. Allen T.R., Konings R.J.M., Motta A.T. Corrosion of Zirconium Alloys. Comprehensive Nuclear Materials. 2012, v. 5, pp. 49-68. DOI: https://doi.org/10.1016/B978-0-08-056033- 5.00063-X .

  18. Hudson Daniel, Ni Na, Lozano-Perez Sergio, Saxey David, English Colin, Smith George D.W., Sykes John, Grovenor Chris. The Atomic Scale Structure and Chemistry of the Zircaloy-4 Metal- Oxide Interface. Proc. of the XIVth International Conference on Environmental Degradation of Materials in Nuclear Power Systems, Virginia Beach, VA, August 23-27, 2009, p. 1407.

  19. Ni N., Hudson D., Wei J., Wang P., Lozano-Perez S., Smith G.D.W., Sykes J.M., Yardley S.S., Moore K.L., Lyon S., Cottis R., Preuss M., Grovenor C.R.M. How the Crystallography and Nanoscale Chemistry of the Metal/Oxide Interface Develops during the Aqueous Oxidation of Zirconium Cladding Alloys. Acta Materialia. 2012, v. 60, pp. 7132-7149. DOI: https:// doi.org/10.1016/j.actamat.2012.09.021 .

  20. Hillner E., Franklin D.G., Smee J.D. Long-term corrosion of Zircaloy before and after irradiation. Journal of Nuclear Materials. 2000, v. 278, pp. 334-345. DOI: https://doi.org/ 10.1016/S0022-3115(99)00230-5 .

  21. Kass S. Aqueous corrosion of the zircaloys at low temperatures. Journal of Nuclear Materials. 1969, v. 29, iss. 3, pp. 315-321. DOI: https://doi.org/10.1016/0022-3115(69)90208-6 .

  22. Krasnoyarsky V.V., Frenkel G.Ya., Nosov R.P. Corrosion and metal protection. Moscow. Metallurgy Publ.,1969. 299 p. (in Russian) 23. Korolev S.A., Mikheev V.P. Sensors and detectors of physical and energy facility. Tutorial. Moscow. NRNU MEPhI Publ., 2011 (in Russian).

corrosion fuel element zirconium alloy oxide film galvanic effect electrochemical potential