Uranium deposition study on aluminum: results of early tests

Technical Report · Tue Jun 19 04:00:00 EDT 1984

OSTI ID:6783808

Hughes, M R; Nolan, T A

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 UF/sub 6/ (0.7% /sup 235/U) in nickel reaction vessels under various conditions of UF/sub 6/ pressure, temperature, and time. To-date, runs from 5 minutes to 2000 hr have been completed at a UF/sub 6/ pressure of 100 torr and at a temperature of 60/sup 0/C. Longer exposure times are in progress. Initial results indicated that a surface film of uranium, primarily as uranyl fluoride (UO/sub 2/F/sub 2/), is deposited very soon after exposure to UF/sub 6/. In a five minute UF/sub 6/ exposure at a temperature of 60/sup 0/C, an average of 2.9 ..mu..g U/cm/sup 2/ was deposited; after 24 hr the deposit typically increased to 5.0 ..mu..g/cm/sup 2/ and then increased to 10.4 ..mu..g/cm/sup 2/ 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 UF/sub 6/ 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 UF/sub 6/ 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.

• Research Organization: Oak Ridge Gaseous Diffusion Plant, TN (USA)
• DOE Contract Number: AC05-84OT21400
• OSTI ID: 6783808
• Report Number(s): K/PS-819; ON: DE84017575
• Country of Publication: United States
• Language: English

Related Subjects

050502* -- Nuclear Fuels-- Uranium Enrichment-- Centrifugation-- (-1989)
055001 -- Nuclear Fuels-- Safeguards
Inspection
& Accountability-- Technical Aspects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION
ACTINIDE COMPOUNDS
ACTINIDES
ALUMINIUM
CENTRIFUGE ENRICHMENT PLANTS
DEPOSITION
DEPOSITS
ELEMENTS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
INDUSTRIAL PLANTS
ISOTOPE SEPARATION PLANTS
METALS
NUCLEAR FACILITIES
PIPES
URANIUM
URANIUM COMPOUNDS
URANIUM FLUORIDES
URANIUM HEXAFLUORIDE
URANYL COMPOUNDS
URANYL FLUORIDES