Alloying of U-Al-SS as a Simulant for Pu-Al-SS Alloying

Abstract

The Savannah River National Laboratory (SRNL) evaluated several options for disposition of stainlesssteel clad plutonium metal, particularly Pu-10.6 atomic % Al (Pu-1.3 wt % Al) alloy fuel. One technology considered was alloying fuel with stainless steel (SS). The goal of the alloying would be to make a SS-Pu alloy that was a non-proliferable waste form with secondary Pu rich microencapsulated regions distributed throughout the refractory stainless steel. The microencapsulation of the Pu regions should therefore allow the waste form to meet the requirements for a low attractiveness waste as defined by the United States Department of Energy (DOE). Pu bearing alloys at these levels could potentially be suitable for disposal at WIPP. Four metal ingots were successfully fabricated using U and Al as a surrogate for Pu-Al. The U was distributed and microencapsulated by the alloy matrix, thereby setting the stage for subsequent tests using SS-clad fuel elements containing Pu-10.6Al.