Enhanced Mechanical Properties of Iron-Chromium-Aluminum Cladding for Light Water Reactor Fuels

Abstract

Iron-chromium-aluminum (FeCrAl) alloys are being characterized to be used in light water reactors for the cladding of the fuel. This family of alloys were never used before in a reactor environment so their behavior should be evaluated. This manuscript describes the enhanced mechanical properties and thermal creep resistance of two FeCrAl alloys (PMC26M & FA-SMT or APMT-2) as compared with the current Zircaloy-2 based cladding. At 450°C and under a nominal hoop stress of 138 MPa (20ksi), Zircaloy-2 tubes suffer rapid creep while the two FeCrAl alloys do not show any evidence of creep at a higher nominal hoop stress of 324 MPa (47 ksi). FA-SMT had higher creep resistance than PMC26M at 600°C and 800°C mainly due to precipitate strengthening in FA-SMT.