Chemical and radiochemical analysis of corrosion products on BWR fuel surfaces

This paper aimed at the characterization of the metallic composition and surface analysis of fuel rod Chalk River Unidentified Deposit (crud) for a BWR-6 unit at a nuclear power plant. In this study, inductively coupled plasma-atomic emission spectroscopy and gamma spectrometry were carried out to analyze the corrosion product distributions and to determine the elemental compositions along the fuel rod under conditions of hydrogen water chemistry (HWC) switched from normal water chemistry (NWC) as the reactor coolant. Most of the crud consisted of flakes and irregular shapes via scanning electron microscope morphology. The loosely adherent oxide layer was mostly composed of hematite (α-Fe₂O₃) with amorphous iron oxides, as determined using X-ray diffractometer results. The deposited amount of crud was the order of 0.2 mg/cm², suggesting that the fuel surface of this plant under the HWC environment appeared to have lower crud deposition due to low feedwater iron levels. There was also no significant difference in comparison with the NWC condition.