Microstructural characterization of U‐Zr alloy fuel slugs for sodium‐cooled fast reactor

Abstract

In order to investigate a fabrication process of metallic fuel for sodium‐cooled fast reactor, U‐Zr fuel slugs were fabricated with gravity casting and injection casting. In order to reduce the formation of radioactive wastes, and to have a fine microstructure, spherical powder of U‐Zr alloy was also fabricated by centrifugal atomization. The microstructural characteristics were investigated by using electron microscopes and energy‐dispersive electron X‐ray spectroscope. U‐10wt.%Zr fuel slugs had some dispersion phases of Zr precipitates and Zr compounds of about 5 µm in size. The matrix was composed of fine laminar structure of about 0.15 µm in thickness. U grains became finer from about 30 µm in conventionally cast fuel slug to about 2 µm in atomized powder. Laminar structure became so fine from 0.2 µm in conventionally cast fuel slug to 0.1 µm in atomized powder. It is possible for atomized metallic fuel to have a fine microstructure, resulting in a higher fission gas release rate during irradiation. Copyright © 2012 John Wiley & Sons, Ltd.

Fabrication of U-10 wt.%Zr Metallic Fuel Rodlets for Irradiation Test in BOR-60 Fast Reactor

“…Dispersion phases, similar to the fuel slugs fabricated by gravity casting, were composed of Zr-rich phases such as UZr 2 or Zr particulates of about 5 mm in size. The matrix was also composed of a laminar structure in 0.2 m in thickness, similar to the microstructure of the fuel slugs cast into the graphite mold by gravity casting method [20]. The quality of the fuel slugs for the irradiation test was verified through a quality inspection.…”

Archives of Metallurgy and Materials

“…metallic particulate fuel is an innovative form for the injection casting of nuclear fuel slugs [11][12]. Spherical u-Zr system particles can be produced with continuous particle size distribution by centrifugal atomization [13][14][15]. metallic particulate fuel has major advantages in the fabrication for remote operation under high radioactive circumstances, any shaped fuels, and the simplification of the process with sodium-free fuel [16][17][18].…”

Ceramic plasma‐spray‐coated graphite crucible for injection casting of fast reactor fuel slugs

“…Traditionally, metal fuels such as the U‐Zr alloy system for SFR have been melted in slurry‐coated graphite crucibles and cast in slurry‐coated quartz tube molds to prevent melt/material interactions . Coating applications in a hot cell are labor‐intensive and operator‐dependent.…”