Decontamination of HEPA filters

Conference · Sat Dec 31 23:00:00 EST 1977

OSTI ID:6941815

Koenst, Jr., J. W.; Lewis, E. L.; Luthy, D. F.

Mound Facility, during many years of plutonium-238 experience, has recovered over 150 kg of plutonium-238. Much of this material was recovered from HEPA filters or from solid wastes such as sludge and slag. The objective of this task was to modify and improve the existing nitric acid leaching process used at Mound so that filters from the nuclear fuel cycle could be decontaminated effectively. Various leaching agents were tested to determine their capability for dissolving PuO/sub 2/, UO/sub 2/, U/sub 3/O/sub 8/, AmO/sub 2/, NpO/sub 2/, CmO/sub 2/, and ThO/sub 2/ in mixtures of the following: HNO/sub 3/-HF; HNO/sub 3/-HF-H/sub 2/SO/sub 4/; and HNO/sub 3/-(NH/sub 4/)/sub 2/Ce(NO/sub 3/)/sub 6/. Adsorption isotherms were obtained for two leaching systems. In some tests simulated contaminated HEPA filter material was used, while in others actual spent glovebox filters were used. The maximum decontamination factor of 833 was achieved in the recovery of plutonium-238 from actual filters. The dissolution was accomplished by using a six-stage process with 4N HNO/sub 3/-0.23M (NH/sub 4/)/sub 2/Ce(NO/sub 3/)/sub 6/ as the leaching agent. Thorium oxide was also effectively dissolved from filter media using a mixture of nitric acid and ceric ammonium nitrate. Sodium carbonate and Na/sub 2/CO/sub 3/-KNO/sub 3/ fusion tests were performed using simulated PuO/sub 2/-contaminated filter media at various temperatures. Approximately 70 wt% of the PuO/sub 2/ was soluble in a mixture composed of 70 wt% Na/sub 2/CO/sub 3/-30 wt% KNO/sub 3/ (heated for 1 h at 950/sup 0/C). 23 figs., 14 tables.

• Research Organization: Mound Facility, Miamisburg, OH (USA)
• DOE Contract Number: EY-76-C-04-0053
• OSTI ID: 6941815
• Report Number(s): MLM-2537(OP); CONF-780819-1
• Country of Publication: United States
• Language: English

Related Subjects

052001* -- Nuclear Fuels-- Waste Processing
053000 -- Nuclear Fuels-- Environmental Aspects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ACTINIDE COMPOUNDS
AIR FILTERS
ALKALI METAL COMPOUNDS
AMERICIUM COMPOUNDS
AMERICIUM OXIDES
AMMONIUM COMPOUNDS
AMMONIUM NITRATES
CARBON COMPOUNDS
CARBONATES
CERIUM COMPOUNDS
CERIUM NITRATES
CHALCOGENIDES
CLEANING
CURIUM COMPOUNDS
CURIUM OXIDES
DECONTAMINATION
DISSOLUTION
EQUIPMENT
FILTERS
HYDROFLUORIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
NEPTUNIUM COMPOUNDS
NEPTUNIUM OXIDES
NITRATES
NITRIC ACID
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLUTONIUM COMPOUNDS
PLUTONIUM DIOXIDE
PLUTONIUM OXIDES
POLLUTION CONTROL EQUIPMENT
POTASSIUM COMPOUNDS
POTASSIUM NITRATES
RARE EARTH COMPOUNDS
SODIUM CARBONATES
SODIUM COMPOUNDS
SULFURIC ACID
THORIUM COMPOUNDS
THORIUM OXIDES
TRANSURANIUM COMPOUNDS
URANIUM COMPOUNDS
URANIUM DIOXIDE
URANIUM OXIDES
URANIUM OXIDES U3O8