Austenitic 316L stainless steel is usually used as the structural material in spent fuel reprocessing facilities. However, the contamination of fission products from spent fuel (especially Cs and Sr) on the surface of facilities will greatly affect its safe decommissioning. In this study, for the first time, with the combination of characterizations of electrochemistry and laserinduced breakdown spectroscopy with two channels, the corrosion and contamination of 316L stainless steel were analyzed in simulated reprocessing environments with HNO 3 concentrations of 3, 6, 8, and 12 M HNO 3 containing Cs and Sr for 7, 14, 21, 30, and 60 days, respectively. The stability order of the passive film of 316L stainless steel in various environments was 12 M HNO 3 > 8 M HNO 3 > 3 M HNO 3 > 6 M HNO 3 . Combined with other characterization methods, a mechanism was proposed. It was found that SrCO 3 , in the matrix, was the main contaminant in the initial 7 days in all environments due to a large number of holes. Then, the dissolution of contaminated steel surface led to the decrease of contaminant, and recontamination occurred after the repassivation of steel. These findings have significant implications for the development and selection of decontamination technology for the contaminated facilities made of 316L stainless steel.
The first results on the activation process and mechanisms of novel quinary alloy Ti–Zr–V–Hf–Nb non-evaporable getter (NEG) film coatings with copper substrates were presented. About 1.075 µm of Ti–Zr–V–Hf–Nb NEG film coating was deposited on the copper substrates by using the DC sputtering method. The NEG activation at 100, 150, and 180 °C, respectively, for 2 h was in situ characterized by x-ray photoelectron spectroscopy (XPS). The as-deposited NEG film mainly comprised the high valence state metallic oxides and the sub-oxides, as well as a small number of metals. The in situ XPS studies indicated that the concentrations of the high-oxidized states of Ti, Zr, V, Hf, and Nb gradually decreased and that of the lower valence metallic oxides and metallic states increased in steps, when the activation temperature increased from 100 to 180 °C. This outcome manifested that these novel quinary alloy Ti–Zr–V–Hf–Nb NEG film coatings could be activated and used for producing ultra-high vacuum.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.