Development and property evaluation of nuclear grade wrought FeCrAl fuel cladding for light water reactors

Abstract

Development of nuclear grade, iron-based wrought FeCrAl alloys has been initiated for light water reactor (LWR) fuel cladding to serve as a substitute for zirconium-based alloys with enhanced accident tolerance. Ferritic alloys with sufficient chromium and aluminum additions can exhibit significantly improved oxidation kinetics in high-temperature steam environments when compared to zirconium-based alloys. In the first phase, a set of model FeCrAl alloys containing 10-20Cr, 3-5Al, and 0-0.12Y in weight percent, were prepared by conventional arc-melting and hot-working processes to explore the effect of composition on the properties of FeCrAlY alloys. It was found that the tensile properties were insensitive to the alloy compositions studied; however, the steam oxidation resistance strongly depended on both the chromium and the aluminum contents. The second phase development focused on strengthening Fe-13Cr-5Al with minor alloying additions of molybdenum, niobium, and silicon. Combined with an

Uniform corrosion of FeCrAl alloys in LWR coolant environments

“…Initially, coupons (~1 × 2 × 0.15cm) of an austenitic stainless steel (310SS), a commercial ferritic alloy (E-Brite), and a commercial FeCrAl alloy (APMT) were exposed alongside disks from a Zircaloy-4 rod used as reference material for a period of three months. Following those exposures, six model FeCrAl alloys prepared at ORNL [30] underwent immersion testing for a period of one year. The six alloys consisted of five distinct compositions with the intention of exploring the effect of major alloying elements (i.e.…”

Materials selection for nuclear applications: Challenges and opportunities

“…Four systems have been studied: 1) silicon-carbide (SiC)-based composites [16][17][18], 2) iron-chromium-aluminum (Fe-Cr-Al) alloys [19,[21][22][23], 3) coated zirconium [24], and 4) molybdenum (Mo) [25]. These four systems were chosen as balanced compromise among the application's requirements.…”

Influence of composition and heating schedules on compatibility of FeCrAl alloys with high-temperature steam

“…The addition of around 20 wt.% Cr (known as third element effect, TEE) reduces the amount of Al needed to establish the protective alumina scale [14]. However, high Cr content in these alloys may trigger potential irradiation embrittlement at typical LWR operating temperatures during service [15,16]. In order to optimize the chemical composition of the FeCrAl-based alloys to make them suitable for nuclear fission application while maintaining their excellent oxidation resistance, the straightforward solution consisting in increasing the Al content and simultaneously decreasing the Cr content is not acceptable due to the pronounced Al negative effect on the workability and mechanical properties (especially ductility) [17].…”

“…In order to optimize the chemical composition of the FeCrAl-based alloys to make them suitable for nuclear fission application while maintaining their excellent oxidation resistance, the straightforward solution consisting in increasing the Al content and simultaneously decreasing the Cr content is not acceptable due to the pronounced Al negative effect on the workability and mechanical properties (especially ductility) [17]. Current studies are focused on preserving a delicate balance between Cr and Al content in conjunction with minor additions of other elements that eliminate or manipulate undesirable attributes [15,[18][19][20].…”