Dispersion model for airborne particulates inside a building

Conference · Sun Jul 01 04:00:00 EDT 1984

OSTI ID:6984029

Perkins, W C; Stoddard, D H

An empirical model has been developed for the spread of airborne radioactive particles after they are released inside a building. The model has been useful in performing safety analyses of actinide materials facilities at the Savannah River Plant (SRP), operated for the US Department of Energy by the Du Pont Company. These facilities employ the multiple-air-zone concept; that is, ventilation air flows from rooms or areas of least radioactive material hazard, through zones of increasing hazard, to a treatment system. A composite of the data for dispersion of airborne activity during 12 actual case incidents at SRP forms the basis for this model. These incidents occurred during approximately 90 plant-years of experience at SRP with the chemical and metallurgical processing of purified neptunium and plutonium after their recovery from irradiated uranium. The model gives ratios of the airborne activity concentrations in rooms and corridors near the site of the release. All data are normalized to the data from the air sampler nearest the release point. The model can be applied in predicting airborne activity concentrations from particulate releases elsewhere, if the facility in question has similar features of floor plan, air velocity, and air flow direction. The multiple-air-zone concept has been applied to many designs of nuclear facilities as a safety feature to limit the spread of airborne activity from a release. The model illustrates the limitations of this concept: it predicts an apparently anomalous behavior of airborne particulates; namely, a small migration against the flow of the ventilation air. The following phenomena are suggested as possible mechanisms for this migration: eddy currents in the air flow; leaks of ventilation air between zones; open doors; movement of personnel during an incident; inadequate flow of ventilation air; and thermal gradients. 2 references, 12 figures, 4 tables.

• Research Organization: Du Pont de Nemours (E.I.) and Co., Aiken, SC (USA). Savannah River Lab.
• DOE Contract Number: AC09-76SR00001
• OSTI ID: 6984029
• Report Number(s): DP-MS-83-136; CONF-840806-2; ON: DE84014961
• Country of Publication: United States
• Language: English

Related Subjects

053000 -- Nuclear Fuels-- Environmental Aspects
054000 -- Nuclear Fuels-- Health & Safety
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
500300* -- Environment
Atmospheric-- Radioactive Materials Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AEROSOLS
AIR FLOW
AIR POLLUTION
COLLOIDS
DATA
DIFFUSION
DISPERSIONS
FLUID FLOW
FORECASTING
GAS FLOW
INDOOR AIR POLLUTION
INFORMATION
MATHEMATICAL MODELS
MONITORING
NATIONAL ORGANIZATIONS
NUMERICAL DATA
POLLUTION
RADIATION MONITORING
RADIOACTIVE AEROSOLS
SAFETY
SAMPLING
SAVANNAH RIVER PLANT
SOLS
US AEC
US DOE
US ERDA
US ORGANIZATIONS
VENTILATION