Influence of rainfall characteristics on elimination of aerosols of cesium, strontium, barium and tellurium deposited on grassland.

摘要: This work is aimed at quantifying foliar transfer of cesium, strontium, barium and tellurium under the influence rainfall characteristics (intensity, frequency time elapsed between contamination first rainfall). Grassland boxes were contaminated by dry deposition multi-element aerosols (137)Cs, (85)Sr, (133)Ba (123m)Te. They grown in a greenhouse controlled conditions. The treatments consisted mowing applying rainfalls (8 30 mmh(-1)) different times after contamination. At leaf area index 5.9+/-1.9, interception was similar for 4 radionuclides (83.8+/-5.9%). Dew produced significant radionuclide accumulation base vegetation to soil. For moderate intensity, an early (2 days contamination) as efficient, terms wash-off, longer occurring later (6 contamination). rainfalls, eliminated activities comparable because rain intensity compensated duration. However, late wash-off efficiency increased with intensity. Total factors (TTF) determined on whole grass immediately harvest. After medium did not total (about 0.2, 0.3 0.35 Bq kg(fresh weight)(-1) m(-2), respectively). Cesium TTF value lower case weekly (0.1 against 0.2 Bqm(-2)). values twice-a-week whatever their higher rains high (between 0.75 Bqm(-2) 0.1-0.35 depending radionuclides). attested that more efficient when lasted longer. Field loss top leaves well described offset exponential model. half-lives varied from strontium 20 tellurium. 0% (high rainfalls) 14% cesium (medium rainfalls).