Fouling behavior on the zircaloy-4 alloy cladding tube: An experimental and simulation study

[Display omitted] •The structural evolution of the oxide layer on Zr-4 fuel cladding is characterized.•The high-temperature and high-pressure environment induces the transition in ZrO2.•Prolonged oxidation leads to the formation of cracks in the oxide layer.•The nucleation, growth and agglomeration behaviors of Fe3O4 and NiFe2O4 are revealed. The essential safeguard provided by cladding tube in pressurized water reactor for nuclear fuel assembly leads to an investigation into the fouling behavior of Zircaloy-4 fuel cladding. This was carried out through a combination of experiments and simulations, employing a purpose-designed autoclave to simulate the flow fouling deposition under high-temperature high-pressure condition. The microstructures of the fouled samples were characterized, and the water chemistry of the corroded solution was analyzed. Furthermore, molecular dynamics simulations offered valuable insights into the binding mechanism, capturing the deposition behavior on the oxide surface and the agglomeration of molecules from a nanoscale perspective.