Study on Cr coated cladding, 2; Investigation of the metallography after LOCA test

Mohamad, A. B. ; Okada, Yuji*; Sato, Daiki*; Ioka, Ikuo  ; Suzuki, Eriko   ; Nemoto, Yoshiyuki  

Chromium (Cr) coated zirconium (Zr) based alloy cladding is the promising material for a near term accident tolerant fuel (ATF). Cr-coated Zr based cladding was fabricated by sputtering technique and simulated LOCA tests were conducted up to different high temperatures (1200C to 1350C). The present work aims to investigate the metallography of Cr-coated Zr cladding after LOCA test. The result showed CrO layers were formed as a protective oxide layer at the outmost layer for all samples. However, Cr-Zr phases were observed for the samples which tested up to 1300C and 1350C, seems that the Cr-Zr reaction had occurred at this temperature. In addition, Cr-Zr layer in the sample tested up to 1350C was thicker than which in the sample tested up 1300C. In particular, the main phases observed in the cross-sectional area were CrO, Cr, ZrO, Cr-Zr, and Zr situated from outer to inner of the sample after LOCA test. The details of the microstructure on these samples will be discussed in the presentation.