Reduced Activation Tungsten for Fusion

Tungsten and its alloys are candidates for plasma facing component heat sinks and armor due to their low sputtering rate, high melting point, high thermal conductivity, high strength at elevated temperatures and low tritium inventory. However during service, the plasma facing components will be exposed to a high flux of 14MeV neutrons from the plasma and low energy neutrons from the blanket, which will result in radiation damage to the tungsten. As a result of these radiation-induced defects, the mechanical and physical properties of the tungsten will be degraded. In addition, radioactive materials increase the cost of operation due to concerns with occupational exposure, accident conditions, and long-term storage/recycling. Therefore, a reduced activation tungsten material would be advantageous for use in a fusion device. During this effort, reduced activation tungsten based on isotope tailoring will be developed. Because of the potential high cost of the isotope tailored tungsten, near-net-shape electrochemical processing techniques will be used to produce the reduced activation tungsten material. During Phase I, low activation tungsten will be produced and the cost benefits of the reduced activation tungsten material will be studied. During Phase II, reduced activation tungsten samples will be produced for testing. Commercial Applications and Other Benefits: The near-net-shape forming of tungsten has tremendous commercial potential. Aside from nuclear fusion applications, electroformed tungsten will be used for non-eroding nozzles in rocket engines, crucibles for crystal growth, heat pipes, welding electrodes, x-ray targets, warhead penetrators, radiation/temperature shielding applications, and other high temperature furnace components.