A model for indoor radon variations

Journal Article · Sun Jan 01 00:00:00 EST 1989 · Environment International; (USA)

DOI:https://doi.org/10.1016/0160-4120(89)90033-0· OSTI ID:6614137

Arvela, H; Winqvist, K ^[1]

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1. Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland)

The model relates radon concentration to variations in source strength, air exchange rate, and meteorological factors. The diffusion source represents radon diffused from building materials or from soil. The pressure-difference driven flow represents radon flowing with soil pore air and driven by the stack effect. In a house with diffusion source, the radon concentration decreases when the air exchange rate increases due to increasing temperature differences, whereas the flow source causes an increasing concentration. This is due to the fact that the effect of the source strength increase is stronger than the decreasing effect of air exchange of concentration. The winter-summer concentration ratio depends on the combination of the two types of source. A pure pressure-difference driven flow gives a winter-summer ratio of 2-3 (winter -5{degree}C, summer +15{degree}C, wind speed 3 m/s). A strong contribution of a diffusion source is needed to cause a summer concentration higher than the winter concentration. The model is in agreement with the winter-summer concentration ratios measured. This ratio increases with the increasing winter concentration. The results indicate that radon concentration must be taken into account in analyses of seasonal variations of indoor radon. In houses with a diffusion source, the diurnal maximum occurs in the afternoon; in houses with a pressure-difference driven flow, the maximum is reached in the early morning.

• OSTI ID: 6614137
• Journal Information: Environment International; (USA), Vol. 15:1-6; ISSN 0160-4120
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
HOUSES
RADIONUCLIDE MIGRATION
RADON
RADIATION MONITORING
AIR POLLUTION
ANNUAL VARIATIONS
BUILDING MATERIALS
DAILY VARIATIONS
DIFFUSION
INDOOR AIR POLLUTION
MATHEMATICAL MODELS
METEOROLOGY
SOILS
BUILDINGS
ELEMENTS
ENVIRONMENTAL TRANSPORT
FLUIDS
GASES
MASS TRANSFER
MATERIALS
MONITORING
NONMETALS
POLLUTION
RARE GASES
RESIDENTIAL BUILDINGS
VARIATIONS
540130* - Environment
Atmospheric- Radioactive Materials Monitoring & Transport- (1990-)