Chemical characterization, leach, and adsorption studies of solidified low-level wastes

Technical Report · Mon Dec 01 04:00:00 EST 1986

DOI:https://doi.org/10.2172/7012709· OSTI ID:7012709

Walter, M B; Serne, R J; Jones, T L; McLaurine, S B

Laboratory and field leaching experiments are beig conducted by Pacific Northwest Laboratory (PNL) to investigate the performance of solidified low-level nuclear waste in a typical, arid, near-surface disposal site. Under PNL's Special Waste Form Lysimeters-Arid Program, a field test facility was constructed to monitor the leaching of commercial solidified waste. Laboratory experiments were conducted to investigate the leaching and adsorption characteristics of the waste forms in contact with soil. Liquid radioactive wastes solidified in cement, vinyl ester-styrene, and bitumen were obtained from commercial boiling water and pressurized water reactors, and buried in a field leaching facility on the Hanford site in southeastern Washington State. Batch leaching, soil column adsorption, and soil/waste form column experiments were conducted in the laboratory, using small-scale cement waste forms and Hanford site ground water. The purpose of these experiments is to evaluate the ability of laboratory leaching tests to predict leaching under actual field conditions and to determine which mechanisms (i.e., diffusion, solubility, adsorption) actually control the concentration of radionuclides in the soil surrounding the waste form. Chemical and radionuclide analyses performed on samples collected from the field and laboratory experiments indicate strong adsorption of /sup 134,137/Cs and /sup 85/Sr onto the Hanford site sediment. Small amounts of /sup 60/Co are leached from the waste forms as very mobile species. Some /sup 60/Co migrated through the soil at the same rate as water. Chemical constituents present in the reactor waste streams also found at elevated levels in the field and laboratory leachates include sodium, sulfate, magnesium, and nitrate. Plausible solid phases that could be controlling some of the chemical and radionuclide concentrations in the leachate were identified using the MINTEQ geochemical computer code.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 7012709
• Report Number(s): PNL-6047; ON: DE87004220
• Country of Publication: United States
• Language: English

Related Subjects

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510300 -- Environment
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54 ENVIRONMENTAL SCIENCES
ADSORPTION
ALKALI METAL ISOTOPES
ALKALINE EARTH ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CESIUM 134
CESIUM 137
CESIUM ISOTOPES
COBALT 60
COBALT ISOTOPES
DATA
DAYS LIVING RADIOISOTOPES
DISSOLUTION
ELECTRON CAPTURE RADIOISOTOPES
ENVIRONMENTAL TRANSPORT
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
HOURS LIVING RADIOISOTOPES
INFORMATION
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LEACHING
LOW-LEVEL RADIOACTIVE WASTES
MASS TRANSFER
MATERIALS
MINUTES LIVING RADIOISOTOPES
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
RADIOISOTOPES
RADIONUCLIDE MIGRATION
SEPARATION PROCESSES
SOILS
SORPTION
SORPTIVE PROPERTIES
STRONTIUM 85
STRONTIUM ISOTOPES
SURFACE PROPERTIES
WASTE FORMS
WASTES
YEARS LIVING RADIOISOTOPES