Preliminary study on FeGd alloys as binary alloys and master alloys for potential spent nuclear fuel (SNF) application

Abstract

One of the biggest challenges of nuclear industries is to fabricate safe, stable and efficient materials for the storage and transportation of spent nuclear fuels (SNFs), these materials are known as neutron shielding and absorbing materials. Recently, Gd has received much attention as a neutron absorbing material in SNF applications owing to its high neutron absorption capability. Herein, we propose novel FeGd alloys as binary alloys and master alloys for potential materials in nuclear applications. FeGd alloys with 20, 55 and 80 wt% Gd were selected based on the FeGd phase diagram. All fabricated FeGd alloys had higher hardnesses than pure Fe due to the formed FeGd phases, and the Fe-rich phase had a higher hardness than the Gd-rich phase. On the other hand, corrosion resistance of the FeGd alloys decreased as the Gd content increased. Satisfactory Gd-based intermetallic dispersion and modifying effects were obtained by casting Fe and stainless-steel alloy with Fe80Gd. The average intermetallic size in the stainless-steel alloy remarkably decreased with a decrease in the average distance between Gd-based intermetallics. FeGd alloys possess requisite hardness, thermal conductivity, and corrosion resistance as well as dispersion ability of intermetallics; hence, they show potential as promising candidates for SNF applications.

Keywords

• Gadolinium
• Iron
• Stainless steel
• Neutron absorbing material
• Thermal conductivity
• Corrosion resistance