[en] Laboratory experiments to quantify uranium compound deposition on Aluminum 3003 test coupons have been initiated. These experiments consist of exposing the coupons to normal assay UF₆ (0.7% ²³⁵U) in nickel reaction vessels under various conditions of UF₆ pressure, temperature, and time. To-date, runs from 5 minutes to 2000 hr have been completed at a UF₆ pressure of 100 torr and at a temperature of 60⁰C. Longer exposure times are in progress. Initial results indicated that a surface film of uranium, primarily as uranyl fluoride (UO₂F₂), is deposited very soon after exposure to UF₆. In a five minute UF₆ exposure at a temperature of 60⁰C, an average of 2.9 μg U/cm² was deposited; after 24 hr the deposit typically increased to 5.0 μg/cm² and then increased to 10.4 μg/cm² after 2000 hr. This amount of deposit (at 2000 hr exposure) would contribute roughly 10 to 20% to the total 186 keV gamma signal obtained from a GCEP product header pipe being operated at UF₆ pressures of 2 to 5 torr. The amount of isotopic exchange which would occur in the deposit in the event that HEU and LEU productions were alternated is considered. It is felt that isotopic exchange would not occur to any significant amount within the fixed deposit during relatively short HEU production periods since the HEU would be present primarily as adsorbed UF₆ molecules on the surface of the deposit. The adsorbed HEU molecules would be removed by evacuation and diluted by LEU production. Major increases in the deposit count would be observed if a leak occurred or moisture was introduced into the system while HEU was being produced