Effects of metal ion concentration on deposition chemistry of Corrosion Related Unidentified Deposits in PWR fuel cladding

Abstract

An experimental facility was set up to investigate the effect of metal ion concentration on the formation of CRUD on fuel cladding in simulated pressurized water reactor primary water. The structural and chemical characteristics of the specimens were examined and it was found that the thickness of the CRUD increased with the metal ion concentration. At lower concentrations, a primitive CRUD chimney structures were observed, while higher concentrations led to more developed ones. Chemical analysis indicated more Ni oxide deposition at lower concentrations. Despite thicker CRUD at higher concentrations, enhanced chimney structures improved thermal conductivity by promoting heat transfer through wick boiling behavior.