BURNUP ENHANCEMENT FOR RE-ENTERING NAP SYSTEMS,
Abstract:
The feasibility of enhancing the atmospheric burnup of a ZrH-uranium nuclear fuel upon reentry from orbit by addition of small amounts of alloying elements to the fuel was studied. Thirty-eight different modified fuel compositions were prepared and evaluated. The effects of various additives on fluidity, fabricability, ease of hydriding, hardness, and microstructure of the fuel alloy were determined. Thirty-two separate model fuel elements representing 25 most promising alloys based upon their apparent fluidity and ease of hydriding were exposed to simulated re-entry conditions in the exhaust of an oxygen-hydrogen rocket motor. Samples were exposed for 2.5 to 8.0 seconds at a stagnation heat flux level of approximately 370 Btusq ft sec. Ablation was noted in all samples. Under the test conditions imposed, the products of ablation of the reference hydride fuel were definitely molten. A phenomenology of the ablation of the reference hydride fuel was described in some detail. Author