Caesium and its Mixtures: Their Chemical Reactions with Alloys of Transition Metals Used to Clad Reactor Fuels

Abstract

The elements Cs, Te and O₂ are considered to be the primary corrodants during burn-up of mixed oxide UO₂/PUO₂ fuel in Fast Breeder Nuclear Reactors, and the alloys PE16 and 12R72HV comprise advanced forms of fuel cladding to replace the originally employed M316 steel. The steels FV448 and DT2203Y05 are members of a ferritic class of alloys that might also play a role in the cladding under conditions of high burn-up. Most of the work [1– 5] was devoted to determining the extent and nature of corrosion of the alloys PE16, 12R72HV, M316, FV448 and DT2203Y05 by Cs/Te/O₂ mixtures in sealed capsules for an arbitrary time of 168 h at 948 K, a temperature probably typical of the clad temperature in an operating fuel pin.