Izvestiya vuzov. Yadernaya Energetika

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

Analysis of operational factors that can lead to fuel failure in WWER units

12/29/2014 2014 - #04 Physics and technology of nuclear reactors

Evdokimov I.A. Likhanskij V.V. Sorokin A.A. Zborovskij V.G. Kozhakin A.N. Chernetskij M.G. Shestakov Yu.M. Semenovykh A.S.

DOI: https://doi.org/10.26583/npe.2014.4.12

UDC: 621.039.548

Fuel failure is likely to occur during operation of nuclear power units. Failure may result in escalation of primary coolant activity. Hydrogen uptake by cladding is high in failed fuel rods. Under certain conditions it may lead to secondary degradation and formation of coarse defects in cladding. Fuel washout becomes possible in case of severe cladding degradation with ensuing contamination of primary circuit. Fuel failure necessitates high-cost activities on detection of leaking fuel. Expensive mitigating procedures may be needed as well. The present paper is focused on fuel failure in WWER units in the period of 2003 through 2013. The data of visual inspections and post-irradiation examinations of leaking fuel assemblies in hot cells are reported. Degradation of defective fuel rods is related to fuel operation conditions. The threshold conditions are estimated which lead to severe secondary degradation of leaking fuel and substantial increase in release of fission products into primary coolant. The accumulated data are summarized in relation to possible impact of operational factors on the rate and causes of fuel failures.


  1. Edsinger K., Cheng B., Daum R., Deshon J., Hussey D., Kucuk A., Mader E.V., Pytel M., Peitmeyer M., Yagnik S.K., Yueh K. Zero by 2010 and recent U.S. fuel reliability experience. [Proc. Water Reactor Fuel Performance Meeting (Top Fuel)]. Chengdu, China, Sept.11-14, 2011, paper T2-41.
  2. Evdokimov I.A., Likhanskii V.V. In-Pile Criteria for the Initiation of Massive Hydriding of Zrin Steam-Hydrogen Environment. Journal of ASTM International, v.5, no.1, 2008.
  3. Evdokimov I.A., Likhanskii V.V., Aliev T.N., Sorokin A.A., Kanukova V.D. Secondary Hydriding Criteria Under Irradiation Conditions. Nuclear Eng. and Design. 2011, v. 241, pp.1414-1420.
  4. Spravochnik po nadezhnosti topliva. Ofitsialnyj sait VAO AES (Fuel Reliability Reference Manual. Official site of WANO) Available at: http://www.wano.info/en-gb (accessed 04.06.2014)
  5. Bairiot H., et al. Fuel failure in normal operation of water reactors: experience, mechanisms and management. IAEA-TECDOC-709, Vienna, Austria, 1993.
  6. Alvarez L., et al. Review of fuel failures in water cooled reactors. IAEA Nuclear Energy Series No.NF-T-2.1, Vienna, Austria, 2010.
  7. Perrota J.A., et al. Fuel Failure in Water Reactors: Causes and Mitigation. IAEA-TECDOC-1345, Vienna, Austria, 2003.
  8. Locke D.H. The behaviour of defective reactor fuel // Nuclear Engineering and Design. 1972. v.21, no.2, pp. 318-330.

leaking fuel rods cladding failure secondary degradation leakage tests visual inspection post-irradiation examinations