Carbon-14 immobilization via the Ba(OH)/sub 2/8H/sub 2/O process

Conference · Fri Jan 01 04:00:00 EST 1982

OSTI ID:7153496

Haag, G L; Nehls, Jr, J W; Young, G C

The airborne release of /sup 14/C from various nuclear facilities has been identified as a potential biohazard due to the long half-life of /sup 14/C (5730 yrs) and the ease in which it may be assimilated into the biosphere. At Oak Ridge National Laboratory, technology is under development, as part of the Airborne Waste Management Program, for the removal and immobilization of this radionuclide. Prior studies have indicated that the /sup 14/C will likely exist in the oxidized form as CO/sub 2/ and will contribute slightly to the bulk CO/sub 2/ concentration of the gas stream, which is airlike in nature (approx. 330 ppMv CO/sub 2/). The technology under development utilizes the CO/sub 2/ - Ba(OH)/sub 2/ 8H/sub 2/O gas-solid reaction with the mode of gas-solid contacting being a fixed bed. The product, BaCO/sub 3/, possessing excellent thermal and chemical stability, prerequisites for the long-term disposal of nuclear wastes. For optimal process operation, studies have indicated that an operating window of adequate size does exist. When operating within the window, high CO/sub 2/ removal efficiency (effluent concentrations < 100 ppBv), high reactant utilization (> 99%), and an acceptable pressure drop across the bed (3 kPa/m at 13 cm/s superficial velocity) are possible. This paper will address three areas of experimental investigation. These areas are (1) micro-scale studies on 150-mg samples to provide information concerning surface properties, kinetics, and equilibrium vapor pressures, (2) macro-scale studies on large fixed beds (4.2 kg reactant) to determine the effects of humidity, temperature, and gas flow-rate upon bed pressure drop and CO/sub 2/ breakthrough, and (3) the design, construction, and initial operation of a pilot unit capable of continuously processing a 34 m/sup 3//h (20 ft/sup 3//min) air-based gas stream.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 7153496
• Report Number(s): CONF-820833-10-Draft; ON: DE82020834
• Country of Publication: United States
• Language: English

Related Subjects

052001* -- Nuclear Fuels-- Waste Processing
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM HYDROXIDES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON 14
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON ISOTOPES
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
DATA
DIAGRAMS
EVEN-EVEN NUCLEI
EXPERIMENTAL DATA
FLOWSHEETS
GASEOUS WASTES
HYDRATES
HYDROGEN COMPOUNDS
HYDROXIDES
INFORMATION
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MANAGEMENT
NUCLEAR FACILITIES
NUCLEI
NUMERICAL DATA
OFF-GAS SYSTEMS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PRESSURE DROP
PROCESSING
RADIOACTIVE WASTE PROCESSING
RADIOISOTOPES
SOLIDIFICATION
TEMPERATURE EFFECTS
TIME DEPENDENCE
WASTE MANAGEMENT
WASTE PROCESSING
WASTES
YEARS LIVING RADIOISOTOPES