Effect of chemical etching of fuel cladding surface on crud deposition behavior in simulated primary water of PWRs at 328 °C

The purpose of this work is to evaluate the effect of chemical etching of fuel cladding surface on crud deposition and sub-cooled nucleate boiling behavior in simulated primary water of a PWR at 328 °C (601 K) and 13.0 MPa. Crud deposition tests were conducted using an as-received cladding tube and a chemically etched cladding tube under sub-cooled nucleate flow boiling conditions. The boiling behaviors on the two different cladding tubes were also monitored through the acoustic emission technique during the crud deposition tests. The number of boiling events was much smaller on the chemically etched cladding tube than on the as-received cladding tube. The amount of deposit decreased by about 51% on the chemically etched cladding tube compared to that on the as-received cladding tube. The effect of chemically etched surface is discussed from the viewpoint of surface roughness, wettability, and the degree of sub-cooled nucleate boiling.