AN ANALYTICAL NON-STATIONARY DISPERSION-DEPOSITION MODEL
Item
Title (Dublin Core)
eng
AN ANALYTICAL NON-STATIONARY DISPERSION-DEPOSITION MODEL
Description (Dublin Core)
eng
In this work an atmospheric dispersion-deposition model to describe the radionuclides concentration after a hypothetical
nuclear accident is presented. The developed model has two parts. The first one describes the concentration due to the material
released after an arbitrary period from a given source. The second one describes the concentration change during the current period
due to the dispersion of the material that is in the atmosphere. Here the solution for the first part is presented.
A non-stationary analytical solution is obtained from the atmospheric diffusion equation. The model solves the transport (convection-diffusion) equation in which the contaminant settling is explicitly incorporated. Regarding the boundary conditions, it is assumed a null diffusion through the mixed layer top and an albedo at the ground level. From the general solution obtained for the contaminant concentration the Gaussian plume formula is derived as a particular case when it is assumed a stationary point source, vd =0 (total reflection) and vs,=0 (without settling). Assuming vd ≠ 0 and vs,= 0, is compared with the Source Depletion Model (SoDM) and with the Surface Depletion Model (SuDM). The agreement is excellent when comparing with the SuDM, which is the exact solution for the diffusion equation when the settling is modeled only in the boundary condition. Two additional cases are presented, the former is the steady state solution: vd ≠ 0 and vs, ≠ 0, and the last one is a non-stationary simulation with a transport time of 3600 s with vd ≠ 0 and vs, ≠ 0. For the last case, two Erf functions appear in the solution as result of time integration that model the plume front traveling in the atmosphere.
This new contaminant transport model describes the concentration evolution in a more realistic way, representing the plume falling.
This is an improvement respect to the known dispersion-deposition models (SoDM, SuDM).
nuclear accident is presented. The developed model has two parts. The first one describes the concentration due to the material
released after an arbitrary period from a given source. The second one describes the concentration change during the current period
due to the dispersion of the material that is in the atmosphere. Here the solution for the first part is presented.
A non-stationary analytical solution is obtained from the atmospheric diffusion equation. The model solves the transport (convection-diffusion) equation in which the contaminant settling is explicitly incorporated. Regarding the boundary conditions, it is assumed a null diffusion through the mixed layer top and an albedo at the ground level. From the general solution obtained for the contaminant concentration the Gaussian plume formula is derived as a particular case when it is assumed a stationary point source, vd =0 (total reflection) and vs,=0 (without settling). Assuming vd ≠ 0 and vs,= 0, is compared with the Source Depletion Model (SoDM) and with the Surface Depletion Model (SuDM). The agreement is excellent when comparing with the SuDM, which is the exact solution for the diffusion equation when the settling is modeled only in the boundary condition. Two additional cases are presented, the former is the steady state solution: vd ≠ 0 and vs, ≠ 0, and the last one is a non-stationary simulation with a transport time of 3600 s with vd ≠ 0 and vs, ≠ 0. For the last case, two Erf functions appear in the solution as result of time integration that model the plume front traveling in the atmosphere.
This new contaminant transport model describes the concentration evolution in a more realistic way, representing the plume falling.
This is an improvement respect to the known dispersion-deposition models (SoDM, SuDM).
Creator (Dublin Core)
Caputo, Marcelo
Gimenez, Marcelo
Padra, Claudio
Subject (Dublin Core)
eng
Atmospheric Dispersion-Deposition model;Analytical solution of atmospheric diffusion equation
Publisher (Dublin Core)
Croatian meteorological society
Date (Dublin Core)
2008
Type (Dublin Core)
text
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
https://hrcak.srce.hr/64332
eng
https://hrcak.srce.hr/file/96460
Source (Dublin Core)
Hrvatski meteorološki časopis
ISSN 1330-0083 (Print)
ISSN 1849-0700 (Online)
Volume 43
Issue 43/2
Language (Dublin Core)
eng
Rights (Dublin Core)
info:eu-repo/semantics/openAccess
The papers of this Journal are free of charge for personal or educational use, with respect of copyright of authors and publisher.