Foliar contamination of plants with aerosols of137Cs,85Sr,133Ba and123mTe: Influence of rain
| Autor: | T. Bonhomme, D. Poncet-Bonnard, C. Madoz-Escande |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Radionuclide
Strontium Renewable Energy Sustainability and the Environment Health Toxicology and Mutagenesis Transfer factor Public Health Environmental and Occupational Health food and beverages chemistry.chemical_element Contamination Aerosol Deposition (aerosol physics) Nuclear Energy and Engineering chemistry Environmental chemistry Radioactive contamination Environmental science Interception Safety Risk Reliability and Quality Waste Management and Disposal |
| Zdroj: | Radioprotection. 40:S421-S427 |
| ISSN: | 0033-8451 |
| DOI: | 10.1051/radiopro:2005s3-062 |
| Popis: | Two types of plants (lettuce and radish) were contaminated by dry deposition of radioactive aerosols ( 137 Cs, 85 Sr, 133 Ba and 123m Te). Due to the rain efficiency in decreasing radiological contamination of crops, a rain scenario was applied on the two types of plants. These experiments aimed at improving the prediction of the consequences on agricultural products of a nuclear accident occurring on a PWR, and at improving the understanding of the different processes occurring between contamination and harvest. For a plant species at a given stage of its growth cycle, the interception of the four radionuclides was found to be identical and varied from 68% for radish to 75% (at the middle of ripeness stage) or 78% (at the mature plant stage). Using a conceptual model, the predominance between the two processes - washing-off the leaves and absorption through the leaves cuticles allowing translocation - was evidenced. For Cs, Sr and Ba, for both the lettuce and the radish, washing-off on the foliar cover was the most significant during the first rain. The absorption process inside the plant became dominant only from the third rain event. Tellurium had a particular behaviour: it was non-mobile and stayed put on the leaves. The values of the washing-off and absorption coefficients were estimated. The global transfer factor values were dependant on both the radionuclides and the plant species; nevertheless, a higher value was obtained for cesium, regardless of the plant and the rainfall (from 0.06 m².kgfresh -1 for radish to 0.1 m².kgfresh -1 for a whole lettuce). The aim of the experiments conducted under controlled conditions was to acquire further radioecological data required for the operational post-accidental code used to evaluate the consequences on the environment of radioactive emissions. Knowledge of the short term consequences (a few days after deposition) had to be improved. Most specifically, this study has been designed to provide a better understanding of the different mechanisms (aerosol dissolution in rainwater, washing, absorption into leave cuticle) intervening between the radionuclide deposition on the plants and harvest. The studied radionuclides are: cesium, strontium, tellurium, barium; they represent fission products emitted under dry condition (aerosols) during an accidental scenario occurring on a PWR. The selected plants represented a choice of classes of plants used in the operational post-accidental code developed in the IRSN (ASTRAL). |
| Databáze: | OpenAIRE |
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