A Review of Pellet–Clad Interaction Behavior in Zirconium Alloy Fuel Cladding

Pellet–clad interaction (PCI) in zirconium alloy cladding has been a long-standing concern in the context of nuclear fuel reliability. Mitigation measures have constrained operational limits in combination with modifying the manufacturing process of the cladding, such as adding a composite layer or a protective coating to the inner surface of the cladding. The foregoing remedies have satisfactorily resolved the problem at the expense of restricted operational performance (i.e., maximum power, power ramp limits, and burnup) that limit potential revenue in operation. With the continuing interest in extending performance limits of conventional nuclear fuels and consideration of new fuel designs, current mitigation measures may become less effective, necessitating research efforts to develop new solutions. The objective of this article is to present the current state of understanding of the PCI phenomenon, outline current mitigation strategies, and discuss advancements in experimental and computational techniques to further elucidate the problem. The ultimate goal is to develop a sound scientific understanding of the PCI phenomenon to improve engineering solutions and optimize operational parameters to enhance performance, while maintaining a high level of reliability and safety.