RESULTS OF THE IAEA STUDY OF FUEL FAILURES IN WATER COOLED REACTORS IN 2006-2010

摘要

Since the 1970's, the IAEA has been involved in the analysis of fuel failures in water cooled reactors in normal (non-accident) operational conditions. Results were consecutively published in 1979 (F. Garzarolli, R. von Jan and H. Stehle, "The main causes of fuel element failure in water-cooled power reactors "), and as IAEA Reviews of Fuel Failures in Water Cooled Reactors in 1998 (IAEA Technical Report Series No. 388) and in 2010 (IAEA Nuclear Energy Series No. NF-T-2.1). If the first publication used available literature data and author's personal experience, the two following Reviews were based mainly on fuel performance information from the members of the IAEA Technical Working Group on Fuel Performance and Technology (TWGFPT), with fuel failure statistics and mechanisms in the time spans of 1987-1994 and 1994-2006. The present report was prepared using the same TWGFPT questionnaire as for the last IAEA Review. It summarizes fuel failure rates and causes for 97% of light and heavy water-cooled nuclear power units (PWR, BWR, WWER, and CANDU/PHWR) operated worldwide in 2006-2010. Data on percentage of nuclear power units reported zero in-core leakers are presented for all LWRs. Apart of fuel rod leakers, fuel assembly (FA) issues are also considered, but at qualitative level. Evolution of failure rates for the whole period of the IAEA studies from 1987 to 2010 is presented to reveal long-term tendencies in fuel performance.