Plate-out rates of radon progeny and particles in a spherical chamber

Conference · Mon Jan 01 04:00:00 EST 1990

OSTI ID:5817432

Cheng, Y S; Chen, B T ^[1]; Su, Y F ^[2]

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1. Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Inhalation Toxicology Research Inst.
2. Pacific Northwest Lab., Richland, WA (United States)

In indoor and mining environments, deposition or plate-out'' of radon progeny onto walls occurs simultaneously with attachment of the radon progeny to airborne particles. Attachment and plate-out processes affect the atmosphere in which radon exposures takes place by reducing concentrations and shifting activity size distributions. Both processes have important consequences in determining the deposition pattern and initial dose of inhaled radon progeny. Theoretical deposition models show that turbulence and natural convection in a room are the major factors that influence plate-out rates. Here we describe plate-out measurements for radon progeny and aerosol particles in a spherical chamber under controlled laboratory conditions. The temperature and velocity profiles in still and turbulent air were monitored. A 161-liter spherical aluminum chamber was used to study the mixing. During mixing, air velocity was detected when rotational speeds were higher than 500 rpm. Monodisperse silver aerosols and polystyrene latex particles in the size range of 5 nm to 2 {mu}m were used in the deposition study. Radon-220 progeny were generated by passing Rn-220 gas into the chamber and letting the gas decay into {sup 212}Pb. The deposition rates of the particles and radon progeny ({sup 212}Pb) in the chamber were determined by monitoring the concentration decay of the aerosol as a function of time.

• Research Organization: Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Inhalation Toxicology Research Inst.
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-76EV01013
• OSTI ID: 5817432
• Report Number(s): CONF-901010-9; ON: DE92004256
• Country of Publication: United States
• Language: English

Related Subjects

560101* -- Biomedical Sciences
Applied Studies-- Radiation Effects-- Dosimetry & Monitoring-- (1992-)
61 RADIATION PROTECTION AND DOSIMETRY
AEROSOLS
AIR POLLUTION
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
COLLOIDS
CONVECTION
DEPOSITION
DISPERSIONS
DOSES
ELEMENTS
ENERGY TRANSFER
EVEN-EVEN NUCLEI
HEAT TRANSFER
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
INHALATION
INTAKE
ISOTOPES
LEAD 212
LEAD ISOTOPES
MASS TRANSFER
MATERIALS
METALS
MIXING
NATURAL CONVECTION
NUCLEI
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PARTICLE SIZE
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
POLLUTION
POLYMERS
POLYOLEFINS
POLYSTYRENE
POLYVINYLS
RADIATION DOSES
RADIOISOTOPES
RADON 220
RADON ISOTOPES
SECONDS LIVING RADIOISOTOPES
SILVER
SIZE
SOLS
SURFACES
SYNTHETIC MATERIALS
TRANSITION ELEMENTS
TURBULENCE
VELOCITY
WALLS