Subsurface de-alloying during SCW exposure

Selection of fuel cladding materials for Canadian Supercritical Water-cooled Reactor (SCWR) faces major challenges due to severe operating conditions (650°C and 25 MPa). High temperature microstructure stability and excellent resistance to general corrosion and stress corrosion cracking are key criteria in fuel cladding alloy selection. This paper reports our recent findings of subsurface de-alloying of some candidate alloys exposed to supercritical water (SCW), which may lead to potential threat to the lifetime structural integrity of fuel cladding components. Copyright © 2014 by The Minerals,Metals & Materials Society.