Modelling transport and deposition of caesium and iodine from the Chernobyl accident using the DREAM model

Abstract

Abstract. A tracer model, DREAM (the Danish Rimpuff and Eulerian Accidental release Model), has been developed for modelling transport, dispersion and deposition (wet and dry) of radioactive material from accidental releases, as the Chernobyl accident. The model is a combination of a Lagrangian model, that includes the near source dispersion, and an Eulerian model describing the long-range transport. The performance of the transport model has previously been tested within the European Tracer Experiment, ETEX, which included transport and dispersion of an inert, non-depositing tracer from a controlled release. The focus of this paper is the model performance with respect to the deposition of 137Cs, 134Cs and 131I from the Chernobyl accident, using different relatively simple and comprehensive parameterizations. The performance, compared to measurements, of different combinations of parameterizations of wet and dry deposition schemes has been evaluated, using different statistical tests.

Potential Threats from a Likely Nuclear Power Plant Accident: a Climatological Trajectory Analysis and Tracer Study

“…When compared with previous studies (e.g. UNSCEAR 1988;Pöllänen 1997;Brandt et al 2002;UN Chernobyl Forum 2005), the model gave a similar distribution of radioactive plumes during the Chernobyl accident. Besides a satisfactory model performance, this simulation is the first study to show the Chernobyl effects over Turkey.…”

An intercomparison of four wet deposition schemes used in dust transport modeling

“…Therefore this scheme is widely used in particulate matter modeling (e.g. Brandt et al, 2002). The scavenging coefficient, λ 2 , is given by…”

“…ApSimon et al (1985) used A = 1 × 10 − 4 and B=0.8. In this study, we use A = 8.4 × 10 − 5 and B = 0.79 for both convective and large-scale precipitation, following Brandt et al (2002).…”

Observations and modelling of thoron and its progeny in the soil–atmosphere–plant system

“…The effect of washout on concentrations of 212 Pb in the atmosphere is modelled as (Brandt et al, 2002) vC atm 212 ðz; tÞ vt ¼ ÀLðIÞ$C atm 212 ðz; tÞ…”

“…The widely used parameterisation L ¼ a $ I b (I given in mm h À1 ) has been adopted with a ¼ 8.4 Â 10 À5 and b ¼ 0.79 (Brandt et al, 2002).…”