Modeling radon entry into houses with basements: Model description and verification

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:6103637

Revzan, K L; Fisk, W J; Gadgil, A J

We model radon entry into basements using a previously developed three-dimensional steady-state finite difference model that has been modified in the following ways: first, cylindrical coordinates are used to take advantage of the symmetry of the problem in the horizontal plant; second, the configuration of the basement has been made more realistic by incorporating the concrete footer; third, a quadratic relationship between the pressure and flow in the L-shaped gap between slab, footer, and wall has been employed; fourth, the natural convection of the soil gas which follows from the heating of the basement in winter has been taken into account. The temperature field in the soil is determined from the equation of energy conservation, using the basement, surface, and deep-soil temperatures as boundary conditions. The pressure field is determined from Darcy's law and the equation of mass conservation (continuity), assuming that there is no flow across any boundary except the soil surface (atmospheric pressure) and the opening in the basement shell (fixed pressure). After the pressure and temperatures field have been obtained the velocity field is found from Darcy's law. Finally, the radon concentration field is found from the equation of mass-transport. The convective radon entry rate through the opening or openings is then calculated. In this paper we describe the modified model, compare the predicted radon entry rates with and without the consideration of thermal convection, and compare the predicted rates with determined from data from 7 houses in the Spokane River valley of Washington and Idaho. Although the predicted rate is much lower than the mean of the rates determined from measurements, errors in the measurement of soil permeability and variations in the permeability of the area immediately under the basement slab, which has a significant influence on the pressure field, can account for the range of entry rates inferred from the data. 25 refs., 8 figs.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• Sponsoring Organization: DOE; USDOE, Washington, DC (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6103637
• Report Number(s): LBL-27742; CONF-900724--10; ON: DE91009330
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540130* -- Environment
Atmospheric-- Radioactive Materials Monitoring & Transport-- (1990-)
AIR POLLUTION
ALPHA DECAY RADIOISOTOPES
BASEMENTS
BUILDING MATERIALS
BUILDINGS
CONCRETES
DARCY LAW
DATA
DATA COVARIANCES
DAYS LIVING RADIOISOTOPES
DIFFUSION
ECOLOGICAL CONCENTRATION
ENERGY TRANSFER
ENVIRONMENTAL TRANSPORT
EVEN-EVEN NUCLEI
FINITE DIFFERENCE METHOD
HAZARDS
HEALTH HAZARDS
HEAT TRANSFER
HEAVY NUCLEI
INDOOR AIR POLLUTION
INFORMATION
ISOTOPES
ITERATIVE METHODS
MASS TRANSFER
MATERIALS
MATHEMATICAL MODELS
NUCLEI
NUMERICAL DATA
NUMERICAL SOLUTION
PERMEABILITY
POLLUTION
PRESSURE GRADIENTS
RADIOECOLOGICAL CONCENTRATION
RADIOISOTOPES
RADIONUCLIDE MIGRATION
RADON 222
RADON ISOTOPES
RESIDENTIAL BUILDINGS
SOILS
STEADY-STATE CONDITIONS
TEMPERATURE GRADIENTS
TESTING
THEORETICAL DATA
THREE-DIMENSIONAL CALCULATIONS
VALIDATION