Design and performance considerations of coolant cladding interaction

Crud deposits and cladding corrosion directly affect the fuel rod performance by an immediate consequence which is a cladding temperature increase. The ultimate damage which results from such a temperature increase is a perforation of the cladding. In order to eliminate or at least to postpone this event, the design must define adequate specifications firstly to reduce the cladding corrosion and, secondly, to operate fuel rods with oxide layers. The first aspect is related to the fuel and assembly design, and to the operation of the primary circuit; the second aspect is related to power history (and therefore core design). The present chapter briefly summarizes the conditions which enhance crud deposition and corrosion, the consequences of corrosion and some remedies which can limit the crud deposits and cladding oxidation