The Canadian experimental HT release of June 10, 1987, US measurements
In June 1987, an experiment was performed at the Chalk River Nuclear Laboratories in Ontario, Canada, to study the oxidation of elemental tritium (HT) released to the environment. The experiment involved a 30-minute release of 3.54 TBq (95.7 Ci)of HT to the atmosphere at an elevation of one meter. Scientists from six countries participated in the experiment. The air measurements showed HT concentrations downwind of the release in general agreement with classical atmospheric diffusion (Gaussian) up to the maximum distance measured (400 m). The HTO/HT ratios were shown to slowly increase downwind (approx. 4 x 10/sup /minus/5/ at 50 m to almost 10/sup /minus/3/ at 400 m) as conversion of HT took place. After the release, HTO concentrations in the atmosphere remained elevated. Vegetation samples were also taken since the vegetation and associated soil system have been implicated in the oxidation of HT. Freeze-dried water from vegetation samples was found to be low in HTO immediately after the release suggesting a low direct uptake of HTO in air by vegetation. The tritiated water concentration increased during the first day, peaking during the second day (about 15--30 kBq/L of water at 50 m from the source), and decreasing by the end of the second day. This pattern suggests oxidation in the soil followed by plant uptake through sorption of soil water. This was confirmed by measurements taken by other groups at the experiment site. The HTO in vegetation decreased with distance downwind with the same pattern as the HT measured during the release indicating that the oxidation of HT was linearly related to the HT concentration in the atmosphere during the exposure period. An adequate description of the process can be made through the observed phenomenon of HT deposition into the soil with subsequent rapid oxidation by soil bacteria. 30 refs., 10 figs., 4 tabs.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 6683617
- Report Number(s):
- LA-11368-MS; ON: DE89002103; TRN: 88-037518
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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US team measurements during the June 1987 experimental HT release at the Chalk River Nuclear Laboratories, Ontario, Canada
Field studies of HT behaviour in the environment
Related Subjects
RADIOECOLOGICAL CONCENTRATION
MATHEMATICAL MODELS
OXIDATION
TRITIUM
GROUND RELEASE
AIR POLLUTION MONITORING
CANADA
ENVIRONMENTAL IMPACTS
ENVIRONMENTAL TRANSPORT
PLANTS
RADIATION MONITORING
SAMPLING
SOILS
SURFACE AIR
AIR
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHEMICAL REACTIONS
ECOLOGICAL CONCENTRATION
FLUIDS
GASES
HYDROGEN ISOTOPES
ISOTOPES
LIGHT NUCLEI
MANAGEMENT
MASS TRANSFER
MONITORING
NORTH AMERICA
NUCLEI
ODD-EVEN NUCLEI
RADIOISOTOPES
WASTE DISPOSAL
WASTE MANAGEMENT
YEARS LIVING RADIOISOTOPES
500300* - Environment
Atmospheric- Radioactive Materials Monitoring & Transport- (-1989)