Fuel Performance and Fission Product Release Studies for Defected Fuel Elements

Results from numerous in-reactor experiments with uranium dioxide fuel elements that contain defects in the Zircaloy cladding are reviewed. The various factors that influence the rate of physical deterioration of a defected element are examined. Experimental and theoretical investigations into the release behavior of radioactive noble gases and iodine are considered for both the steady-state and transient situation, focusing on the relationship between the release behavior and the state of deterioration of a fuel element. Application of this work to power reactor operation is discussed.