Influence of cover defects on the attenuation of radon with earthen covers

Technical Report · Tue Nov 01 00:00:00 EST 1983

DOI:https://doi.org/10.2172/5411352· OSTI ID:5411352

Kalkwarf, D R; Mayer, D W

Experimental and theoretical evaluations of radon flux through laboratory-scale defective soil columns are presented together with a survey of literature on the formation and prevention of defects in soil covers. This report focuses on air-filled, centimeter-scale defects that are most probable in earthen covers for attenuating radon emission from uranium-mill tailings. Examples include shirnkage and erosion cracks, erosion piping, animal burrows and air channels formed by the biodegradation of vegetation roots. Calculations based on mathematical models indicate that collections of defects which could increase the radon flux from an earthen cover by a factor of two would be easily detected by visual inspection. However, these models ignore air-turbulence in the defect and drying of the soil around the defect. Laboratory measurements showed that turbulent diffusion of radon occurred through defects as narrow as 0.3 cm when subjected to a transverse air velocity of 1 to 6 miles per hour at the surface. Both turbulence and more-rapid drying of soil can accelerate radon flux to the cover surface. Consequently, recommended methods to inhibit defect formation should be applied. 29 references, 3 figures, 5 tables.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 5411352
• Report Number(s): NUREG/CR-3395; PNL-4776; ON: DE84004273
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
54 ENVIRONMENTAL SCIENCES
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
RADON
DIFFUSION
SOILS
RADIONUCLIDE MIGRATION
COVERINGS
MILL TAILINGS
RADIOACTIVE WASTE DISPOSAL
ELEMENTS
ENVIRONMENTAL TRANSPORT
FLUIDS
GASES
MANAGEMENT
MASS TRANSFER
NONMETALS
RARE GASES
SOLID WASTES
TAILINGS
WASTE DISPOSAL
WASTE MANAGEMENT
WASTES
054000* - Nuclear Fuels- Health & Safety
053000 - Nuclear Fuels- Environmental Aspects
510301 - Environment
Terrestrial- Radioactive Materials Monitoring & Transport- Soil- (-1987)
052000 - Nuclear Fuels- Waste Management