POOL-SIDE AND HOT CELL EXAMINATIONS OF DUPLEX CLADDING FUEL RODS

摘要

Westinghouse has developed BWR and PWR fuel designs for all major LWR types. The facility in Vaesteras, Sweden, designs and manufactures BWR and PWR fuel, and is the center for 16x16 and 18x18 PWR fuel designs for German type PWRs. The designs for German type PWRs utilize basic design features from Westinghouse Combustion Engineering PWR fuel designs, such as all-Zircaloy mid grids, all-Zircaloy top grids and the Guardian~(TM) debris catcher. The debris filter is integrated in the bottom Inconel grid and it has a very good track record ( <1 debris failure per 10~6 rod years). Other features have been developed to meet with specific European requirements such as high burnup, high coolant temperatures and demanding low-leakage core operating strategies. The most important is the two-layer Duplex cladding that was developed by Westinghouse Atom specifically for the German market demands. The Duplex cladding experience now serves as reference for the development of other cladding materials, such as Zirlo~(TM) that is extensively used in Westinghouse type PWRs, in USA as well as in Europe.