Examination of fuel bundles irradiated in intermittent dryout

The results of the post-irradiation examination of instrumented fuel bundles used for extensive in-reactor critical heat flux and post-dryout heat transfer experiments are presented. The major observations were: central melting of the UO/sub 2/; sheath temperatures much higher than detected during the irradiation; and fuel elements severely bowed. The observations are correlated through a model. Fuel failure is attributed to sheath corrosion at high temperature, and was not related to the central melting. There was no damage to the pressure tube. 5 refs