The rate of reduction of uranium oxide by lithium has been found to be a function of the lithium/salt contact area to salt volume ratio. Three laboratory-scale experiments have been completed in a series of experiments designed to investigate the effect of this ratio on the reduction rate. The results of these experiments show that the rate of reduction increases with increasing lithium/salt contact area up to a certain level, then no further increase in reduction rate is seen above that level. This optimum ration will be carefully defined and then used in future engineering-scale experiments.
Treatment of Aluminum-Based Fuels: Demonstration of the feasibility of electro-metallurgical treatment of aluminum alloy spent fuels, such as foreign and domestic research reactor fuels, has been done in laboratory-scale experiments. The key step in treatment of this fuel is electrorefining of the aluminum, which represents about 90% of the spent fuel volume, and which can, after electrorefining, be discarded as low-level waste. Preparation of the engineering-scale aluminum electrorefiner and the electrolyte salt for beginning aluminum electrorefining was disrupted by a decision to use the same furnace well for testing the prototype Mark-V HTER. A small storage well in the J-118 glovebox is being converted to a furnace well for testing the engineering-scale aluminum electrorefiner.