Sample environment for in situ synchrotron corrosion studies of materials in extreme environments

Abstract

A new in situ sample environment has been designed and developed to study the interfacial interactions of nuclear cladding alloys with high temperature steam. The sample environment is particularly optimized for synchrotron X-ray diffraction studies for in situ structural analysis. The sample environment is highly corrosion resistant and can be readily adapted for steam environments. The in situ sample environment design complies with G2 ASTM standards for studying corrosion in zirconium and its alloys and offers remote temperature and pressure monitoring during the in situ data collection. The use of the in situ sample environment is exemplified by monitoring the oxidation of metallic zirconium during exposure to steam at 350 °C. The in situ sample environment provides a powerful tool for fundamental understanding of corrosion mechanisms by elucidating the substoichiometric oxide phases formed during the early stages of corrosion, which can provide a better understanding of the oxidation process.

High-temperature oxidation of advanced FeCrNi alloy in steam environments

“…Zirconium alloys are used as cladding materials for light water reactors (LWR) due to its low thermal neutron cross section, corrosion resistance, and structural integrity in normal operating conditions [1]. However, they fail under accident conditions, such as a loss-ofcoolant accident (LOCA) due to their oxidation becoming self-catalytic, so engendering the complete oxidation of the cladding and hydrogen release in form of explosions, such as those seen in the Fukushima incident [1,2].…”