Prototypic driver-fuel elements using metallic fuel and stainless-steel cladding, designed to achieve a high burnup, were tested in the Experimental Breeder Reactor II. The irradiation results showed that burnup of up to 10 at.% can be attained without cladding failure and that cladding deformation can be kept to acceptable values if Type 316 stainless steel is used as the cladding material