LOCALIZED CORROSION BEHAVIOR OF FeCrAl NUCLEAR FUEL CLADDING IN POOL STORAGE

摘要

The international materials community is engaged infinding safer alternatives to zirconium alloys in lightwater reactors. One solution is to replace the zirconiumcladding of the nuclear fuel using monolithic ironchromium-aluminum -FeCrAl- alloys or IronClad, whichoffer extraordinary resistance to high temperaturereaction with air or steam due to the formation of aprotective alumina layer on the external surface. It isimportant to characterize the behavior of FeCrAl not onlyduring accident conditions but in the entire fuel cycle,which may include the cooling for 5-20 years in waterpools before the fuel bundles are shipped to dry caskstorage. The main mode of corrosion in water poolscould be general corrosion and localized corrosion suchas pitting corrosion, crevice corrosion, andenvironmentally assisted cracking. Results show that thelocalized corrosion resistance of ferritic alloy FeCrAlfollowed the behavior given by the pitting resistanceequivalent (PRE) number, mostly used previously foraustenitic alloys such as type 304 SS and Inconel 600.APMT, mainly due to its higher chromium andmolybdenum content, was more resistant to localizedcorrosion than type 304 SS. C26M had a similarresistance to localized corrosion than type 304 SS.