8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P2.8Tue 611:23-14:00The effect of rain characteristics on tritium oxidewashout rate from the atmosphereYuri Balashov, 1 Alexey Golubev, 1 Vladimir Piskunov, 1 Sergey Mavrin, 1 ValentinaGolubeva, 1 Alexey Aleinikov, 1 Vladimir Kovalenko, 1 and Igor Solomatin 11 VNIIEF, Mira 37, 607190, Sarov, Russian FederationThe results of the field experiments of HTO washout with rainfall in the vicinity of the HT andHTO emission source are presented. The objective of the current study was to obtain the directexperimental data on the impact of raindrops characteristics (rate and spectrum of the drops) onHTO washout from the atmosphere. The site of the scavenging experiments was around a 30 memission source. The experimental site was a relatively flat one of urban type. To study dependenceof scavenging of tritium on raindrops characteristics, a laser optical device was constructed. Thefollowing parameters were measured in every experiment: temperature and air humidity; HT andHTO activity in a stack gases; rain event parameters, including rain intensity, raindrop’s size andfalling down velocity; HTO activity in rainwater samples, activity of volatile tritiated organicsin water samples. The data of three field experiments is presented. The rate of rainout of HTOfor these experiments is calculated. In the above experiments, the rates of washout Λ estimatedby different ways agree with each other and provide a sound basis for generalizing the results.Parameterized estimate of the washout rate from the intensity of rainfall is obtained. It is simpleand provides good accuracy for calculating the rate of leaching of Λ. The precipitation intensitydependence of the rate of washout can be used for rapid assessment, as well as to determine theparameters of the washout of gases. Obtained parameters can be used to compute transfer andremoval of impurities in the atmosphere. The generalization of the results to the case of rainfallrun-off any gas, not just the HTO, is performed.8