Performance of the Westinghouse WWER-1000 fuel design, 2017 update

62 of Westinghouse WWER-1000 Region Fuel Assemblies (WFAs) have completed their planned four cycles of operation in South Ukraine Unit 3 (SU3) and 27 WFAs have completed two cycles of operation in South Ukraine Unit 2 (SU2). In addition, six Westinghouse WWER-1000 Lead Test Assemblies (LTAs) have also completed their planned four cycles of operation. Post Irradiation Examination (PIE) for the WFAs has been completed after each cycle of operation. During unloading and reloading all assemblies were examined for visible damage or fuel assembly components out of position. All WFAs have also been subject to the standard leak testing process, where each and every fuel rod was found to be hermetically sealed and non-leaking. Each outage, six WFAs have been subject to a more extensive inspection program. After 2012, the Westinghouse Fuel Inspection and Repair Equipment (FIRE) have been used for the inspections. Excellent irradiation fuel performance has been observed and measured on all WFA. The fuel assembly growth, RCCA drag forces, oxide thickness, total fuel rod-to-nozzle gap channel closure and fuel assembly bow data were within the bounds of the Westinghouse experience database. In 2012, several WFAs experienced mechanical damage of the spacer grids during loading of both the SU2 and SU3 cores, but all fuel rods remained hermetically sealed and non-leaking. To further prevent damage of the WFA spacer grids during loading and unloading, Westinghouse has enhanced the WWER-1000 fuel design. 83 of this upgraded Robust Westinghouse VVER-1000 Fuel Assembly (RWFA) have completed irradiation in SU3 and 42 have been irradiated in Zaporizhzhya Unit 5 (Z5). A selected number of RWFAs have been subject to an inspection program after each cycle using the FIRE workstation both in SU3 and in Z5. Excellent irradiation fuel performance has been observed and measured on all inspected RWFAs with all data within the bounds of the Westinghouse experience database. Results and concluding remarks from PIEs are provided in this paper. Currently the RWFA fuel design is operating in SU2, SU3 and Z5 and by the end of 2017 additionally three Ukrainian units will be loaded with RWFA.