A computational methodology for estimation of aerosol retention in a sand-bed based filtering system for severe accident venting strategies
A computational methodology to estimate the capacity of aerosol particle retention in a filter- ing system based on sand bed is described in this work. This methodology uses a combination of computational fluid dynamics and mechanistic models in the calculation procedure. The methodology is...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
VINCA Institute of Nuclear Sciences
2020-01-01
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| Series: | Nuclear Technology and Radiation Protection |
| Subjects: | |
| Online Access: | http://www.doiserbia.nb.rs/img/doi/1451-3994/2020/1451-39942002087C.pdf |
| Summary: | A computational methodology to estimate the capacity of aerosol particle
retention in a filter- ing system based on sand bed is described in this
work. This methodology uses a combination of computational fluid dynamics
and mechanistic models in the calculation procedure. The methodology is
applied to venting actions during a severe accident in a BWR Mark II primary
containment. The SALOME and OpenFoam platforms were used to generate the
geometric and numerical models of a full scale model of a sand bed filtering
system. The Eulerian/Lagrangian approach was used to determine the
steady-state of a compressible turbulent flow through a porous media and to
compute the aerosol particle transport, respectively. Collection
efficiency was calculated by means of a mechanistic model based on the
capture efficiency of a single grain. The obtained Eulerian results include
velocity, pressure, and temperature fields inside the filtering systems. The
Lagrangian tracking of aerosol particles showed that particles crossing the
coarser sand tend to accumulate initially on the periphery of the filter.
The parametric studies showed that mass-flows of up to 4.7 kgs–1 satisfy the
constraint of 1.1 bar pressure drop across the sand depth. Additionally, the
efficiency of 99.5 % of retention was determined for 1.0 μm aerosol
particles in the 0.6 mm sand grain zone, for a gas velocity m of ms–1. |
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| ISSN: | 1451-3994 1452-8185 |