Zero-failure fuel

ABB's SVEA-96/100 fuel is the only fully proven 10x10 fuel in the industry which have attained final burnup in reload quantities. The expected improve ments are now seen in detailed inspections, Hot Cell Post-irradiation Exami nations (PIEs) of high burnup 10x10 fuel, proving very low fission gas rele ase; and PCI free operation Liner fuel mitigates the risk for PCI failures during power ramp operation at higher bum-up. For protection against severe degradation it is necessary to have a liner that is not only mitigating PC I, but also has good corrosion properties, ABB has therefore developed the Zr-Sn liner, which is the only fully operational proven concept against PCI and long axial splits in the industry. Both steam tests of ABB's Zr-Sn lin er and Rot Cell PIE of failed Zr-Sn liner fuel have confirmed a very low co rrosion rate. To date, all the identified ABB 10x10 fuel failures have been due to debris fretting, except one single event of four failed six cycles fuel rods which were affected by ESSC (Enhanced Spacer Shadow Corrosion) du ring 1996-97. ESSC is now effectively remedied, which leaves only debris fr etting as primary failure cause on ABB 10x10 fuel. ABB has now a very good understanding of the cause of primary failures and the generic fuel degrada tion mechanisms. Based on this understanding, ABB has developed effective r emedies both against debris fretting and fuel rod degradation. These remedi es include fretting resistant cladding, mitigating of debris hom the primar y system and fuel assemblies, operation guide lines for operation with a pr imary leaker.