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Gas and Particle Transport

Transport Application for Radiological Consequence Analysis

Particle Transport GOTHIC™ can be used for fission product tracking/retention as well as debris and dust transport. The figure to the right is from a 3D model of a charcoal filter where GOTHIC was used to analyze heating due to radioactive decay of Iodine collected by the filter. GOTHIC predicted the maximum charcoal temperature with natural convection cooling, confirming it was below safety limits for both iodine desorbtion and autoignition/combustion. The GOTHIC analysis and results were used to provide operational flexibility and reduced maintenance costs.

The fundamental aerosol models have been validated or verified against the referenced correlations. Also, GOTHIC has been benchmarked to many integrated effects tests, including Phebus FP (Fission Product). A figure of the test facility and the corresponding GOTHIC model are shown below. The model tracks 98 tracers with radioactive decay and progeny formation, including various iodine isotopes (e.g., 129I, 131I, 132I, 133I and 134I) in various forms (High volatile, Low volatile, Nonvolatile, Molecular). The iodine chemistry is calculated in a separate module that is coupled to GOTHIC. GOTHIC gives good agreement for the buildup and decay of suspended aerosols in Phebus Test 3.
Particle Transport Particle Transport
The range of aerosol and radiological applications that GOTHIC has been used for includes:
Please see the Radiological Consequences Analysis page for addtional dose discussions.

Application Examples

Simulation of results from a GOTHIC™ model of particle transport

This example presents results from a GOTHIC simulation of solid particles transported by water, including the effect of settling, bed load, and resuspension. Liquid laden with 2% particles is horizontally injected in the upper left at a velocity of 2 ft/s for 0-800 seconds and then vertical injection of liquid with increasing velocity over time starts at 800 seconds. A vent is located in the upper right. The animation shows the particle volume fractions and velocity vectors over time.

Particle Transport

During the first part of the simulation particles settle out and form a layer of sediment. Then, the sediment is carried further from the injection location as the vertical velocity increases, which demonstrates the bed load transport. Finally, particles in certain regions are resuspended and swept away entirely by higher velocity flow later in the simulation, but particles are left behind in lower velocity regions created by the flow obstructions.

Analysis Support

For more information on our particle transport analysis and application to your plant, please contact Anita Gates or Steve Winter. The Analysis Division contact list is here, including phone numbers.