b'Figure 2. Microstructures of the Cr- oxidation resistance. On the otherthe Zr alloy cladding. Additionally, wear coating and Zr alloy cladding. hand, the Zr alloy grid that was testedon the counterface (Zr alloy grid) was with the Cr-coated cladding appearedreduced by 58% when the Cr-coating much darker than that against the Zrwas used. In addition, grid wear was alloy cladding after the 100-hr test. Thealso reduced when rubbing against the accelerated oxidization of the Zr gridCr-coated cladding than against the Zr is believed to be caused by galvanicalloy cladding.corrosion promoted by the largeReferences:electrode potential differential between[1.] M. Kennard, D. Sunderland, J.A. Zr (-1.45 V or -2.36 in presence ofHarbottle, Study of Grid-to-Rod OH-) and Cr (-0.74 V). Wear results ofFretting Wear in PWR Fuel Assem-the long tests (AFIR-L, 100 hours) arebly, Stoller Report, April, 1995.plotted and compared with relevant short test results in Figure 4. When[2.] K. A. Terrani, Accident tolerant fuel tested against the as-received Zr alloycladding development: Promise, grid, the wear coefficient of the Zr alloystatus, and challenges, Journal of cladding was almost constant for 20Nuclear Materials, 501 (2018) and 100 hours. This suggests a linear13-30.progression of the wear loss during[3.] B. Qiu, J. Wang, Y. Deng, M. Wang, the fretting test. In contrast, the wearY. Wu, S.Z. Qiu, A review on coefficient of the Cr-coated claddingthermohydraulic and mechanical-was 61% lower in the 100-hr test thanphysical properties of SiC, FeCrAl that in the 20-hr test, indicating aand Ti 3 SiC 2for ATF cladding, significant decrease in wear loss afterNuclear Engineering andrunning-in. The Cr-coating reduced theTechnology, 52 (2020) 1-13.volumetric wear by 94% compared to 68 2020|AFC ACCOMPLISHMENTS'