By Josh Perry, Editor
Researchers from the University of Wisconsin - Madison have studied the emissivity of reactor-alloy surfaces that have been exposed to the high-temperature environments of advanced nuclear reactors, according to a report posted on Science Trends.
This study explores the impact on emissivity of exposure to nuclear reactor environments. (Wikimedia Commons)
The report, which was written by researcher Jonathan King, explained that the study looked at the emissivity of several alloys after being exposed to environments of supercritical CO2 and impurity-rich helium gas. The environments were highly oxidative, and the research showed that new oxidized alloys had much greater emissivities.
On the other hand, environments of liquid sodium and molten salt had little impact on the emissivity of the alloys, with the exception of 316 stainless steel in molten salt, which saw some increase in emissivity that could be due to chromium depletion.
King wrote, “An accurate understanding of heat transfer parameters, such as emissivity, will enable the precise design and operation of advanced nuclear reactors. Our study provides the initial steps towards the capability to accurately predict the emissivity of alloy surfaces as they experience various potentially corrosive high-temperature environments.”
Read more about this study at https://sciencetrends.com/toward-an-accurate-understanding-of-radiative-heat-transfer-in-advanced-nuclear-reactors.
The research was recently published in the Journal of Nuclear Materials. The abstract stated:
“Under standard operating conditions, the emissivity of structural alloys used for various components of nuclear reactors may evolve, affecting the heat transfer of the systems. In this study, mid-infrared emissivities of several reactor structural alloys were measured before and after exposure to environments relevant to next-generation reactors.
“We evaluated nickel-based alloys Haynes 230 and Inconel 617 exposed to helium gas at 1000?°C, nickel-based Hastelloy N and iron-based 316 stainless steel exposed to molten salts at 750–850?°C, 316 stainless steel exposed to liquid sodium at 650?°C, and 316 stainless steel and Haynes 230 exposed to supercritical CO2 at 650?°C. Emissivity was measured via emissive and reflective techniques using a Fourier transform infrared (FTIR) spectrometer.
“Large increases in emissivity are observed for alloys exposed to oxidizing environments, while only minor differences were observed in other exposure conditions.”