Oxidation behavior of Cr-coated Zry cladding in steam environments

水蒸気環境におけるCrコーティング被覆管の酸化挙動

Mohamad, A. B. ; 根本 義之  ; 古本 健一郎*; 岡田 裕史*; 佐藤 大樹*

Mohamad, A. B.; Nemoto, Yoshiyuki; Furumoto, Kenichiro*; Okada, Yuji*; Sato, Daiki*

It is widely recognized that the Cr coating on Zry cladding has shown an improvement in the behavior under accident conditions and normal operation. Many research groups around the world have conducted the high-temperature oxidation and LOCA tests on Cr-coated Zry under accident conditions and explained the degradation phenomena from these tests. Although many literatures have revealed the mechanism and phenomena of the degradation of the Cr-coated, there is still a lack of data on the Zr-Cr-Fe phase or intermetallic phase behavior when the temperature reaches and exceeds the eutectic temperature of Zr-Cr (1332C). In the present study, a high temperature steam oxidation test is carried out from 1100 to 1400C in order to understand the behavior of Cr-coated Zry as it approaches the eutectic temperature. Fromelectron probe microanalysis, the Fe enrichment of the Zr(Cr,Fe) phase is identified for the sample tested at 1300C. In addition, the liquid formation of the Zr(Cr,Fe) phase is observed at 1300C.