High Strength Nickel Alloys for Fuel Assemblies

This Report is a comprehensive review and evaluation of the high strength nickel alloys (625, 718, X-750 and A286) used for PWR/VVER and BWR fuel assembly components. These alloys have been used for spacer grids, bolts and springs since the start of the LWR industry. The report concentrates on the good performance record as well as a description of the reported failures, their causes and remedies. The relationship of various heat treatments to the microstructures and their corrosion resistance are discussed.