Final report to the strategic environmental research and development program on near-net shape casting of uranium-6% niobium alloys

Fabrication methods traditionally used in the fabrication of depleted uranium parts within the Department of Energy (DOE) are extremely wasteful, with only 3% of the starting material actually appearing as finished product. The current effort, funded by the Strategic Environmental Research and Development Program (SERDP) at Los Alamos National Laboratory (LANL), Sandia National Laboratories, Albuquerque (SNLA), and Lawrence Livermore National Laboratory (LLNL), was conceived as a means to drastically reduce this inefficiency and the accompanying waste by demonstrating the technology to cast simple parts close to their final shape in molds made from a variety of materials. As a part of this coordinated study, LLNL was given, and has achieved, two primary objectives: (1) to demonstrate the feasibility of using refractory metal for reusable molds in the production of castings of uranium-6 wt% niobium alloy (U-6Nb); and (2) to demonstrate the utility of detailed simulations of thermal and fluid flow characteristics in the understanding and improvement of the near-net shape casting process. In both cases, our efforts were focused on a flat plate castings, which serve as simple prototypical parts. This report summarizes the results of LLNL work in each area