In situ Raman spectroscopy was employed to investigate corrosion of a zirconium-niobium alloy in air-saturated water at a pressure of 15.5 MPa and temperatures ranging from 22 to 407 C in an optically accessible flow cell. Monoclinic ZrO2 (m-ZrO2) was identified under all conditions after the coupon was heated to 255 C for 19 h. Cubic ZrO2 (c-ZrO2) was tentatively identified in situ during heating at temperatures between 306 and 407 C, but was not observed under any other conditions. Species tentatively identified as α-CrOOH and a CrVI and/or CrIII/CrVI compound were observed in situ during heating at temperatures between 255 and 407 C, but were not observed under any other conditions. The chromium compounds were identified as corrosion products released from the optical cell and/or flow system.
Citation: Journal of Nuclear Materials
Issue: No. 3
Pub Type: Journals
aqueous corrosion, corrosion product release, hydrothermal oxidation, in situ optical spectroscopy, Raman Spectroscopy, zircnium, zirconium oxide, zirconium-niobium, ZrO2