Wet deposition of radionuclides: interception under sprinkler irrigation

Abstract

The paper presents novel data on the interception of radionuclides in vegetables using sprinkler irrigation as a simulator of artificial rain. This information is essential for risk evaluations during both routine operations of nuclear facilities and potential accidental events. In countries with dry climates, where irrigation is an integral part of farming technologies, data on the interception of radionuclides by vegetable crops is crucial for effectively organizing irrigation using cooling water from nuclear reactors. The experiments were conducted in the North Caucasus, a region known for intensive irrigated agriculture, utilizing common vegetable crops such as tomatoes, cucumbers, carrots, table beets, and onions. The research employed a wide range of radionuclides: ⁵⁹Fe, ⁶⁰Co, ⁶⁵Zn, ⁸⁹Sr, ¹⁰⁶Ru, ¹³⁴Cs, and ¹⁴⁴Ce. The study investigated the effects of element properties, plant development stages, and rainfall amounts on radionuclide interception in the crops. It was found that increasing rainfall from 10 to 30 mm resulted in a 1.5– to 3.2–fold increase in the concentration of ⁵⁹Fe and a 1.2– to 3.3–fold increase in the concentration of ¹³⁴Cs in the vegetative mass of plants. A further increase in rainfall, up to 70 mm, did not significantly alter the concentration of either radionuclide in the vegetative mass or the edible parts of the vegetable crops. New approximation was suggested for variations in interception factors with standing biomass of vegetable crops. Based on the strength of their fixation to plant foliage, the radionuclides can be ranked as follows: ⁶⁵Zn ≈ ¹⁴⁴Ce ≥ ⁶⁰Co ≥ ¹⁰⁶Ru > ¹³⁴Cs.