Soil gas measurements below foundation depth improve indoorradon prediction

A soil gas measurement method developed earlier [1] was applied to boreholes drilled to belowfoundation depth. Radon concentration and permeability were measured at 50 cm intervals. Inradon prone areas permeability showed to increase with depth over several orders of magnitude,indicating a low permeability top layer with a thickness of 0.5 m and more. A radon availabilityindex (RAI) was empirically defined and the maximum RAI of each boring proved to be a reliableindicator for radon problems in nearby houses.

Sub-slab depressurisation: overview of important fan characteristics illustrated by laboratory measurements

Within the Belgian Radon Programme the Belgian Building Research Institute is responsible for theinvestigation of techniques for prevention and mitigation of radon problems in dwellings. One of themost regular actions is the installation of a sub-slab depressurisation (SSD) system. As there are noready-to-use systems available on the Belgian market, a system has to be designed for every specificsituation.

Indoor radon measurements in patras, greece, with solid state nuclear track detectors

Measurements of indoor radon (222Rn) concentrations were carried out by using LR-115 II solid statenuclear track detectors (SSNTD). One hundred forty detectors were placed randomly in Patras housesfor two periods of three months exposure, from December 1996 to November 1997. The observedmean radon values compared with the standard recommended values are low, while the maximumrecorded value is found to be within the limits. The influence of seasonal variation as well thedistance from the ground on radon level were also investigated.

Methods for measuring diffusion coefficients of radon in building materials

Two methods for determining the 222Rn diffusion coefficient in building materials are presented.Experimentally, the measurement of radon release rates under well-controlled conditions, using aflush and adsorption technique, underlies both methods. However, the theoretical principle of thetwo methods differs. The first method uses samples with a cubical or rectangular geometry andhas, as a prerequisite that a 100% radon tight surface covering method is available.

Field tests of a radon progeny sampler for the determination of effective dose

The International Commission on Radiological Protection (ICRP) recommends the use of a singleconversion factor, derived from epidemiological studies of exposure to uranium miners, for thedetermination of the effective dose from inhalation of radon progeny. Dosimetric models of radonprogeny inhalation predict that the dose conversion factors (DCF) are dependent upon the form ofthe radon progeny activity size distribution. The measurement of these activity size distributions isdifficult and an alternative approach has been proposed.

Statistical analysis applied to radon and natural events

Soil radon concentrations together with climatic and seismic data were continuously observed in theKanto area (Japan). During fall 1998, several typhoons and earthquakes occurred. In the meanwhile,continuous measurements of the following parameters were carried out: air pressure, temperature inthe air and in the soil, humidity in the soil, wind speeds, wind direction, rainfall and earthquakesmagnitudes.Data were analyzed using time-series analysis method, i.e. Correlation and Spectrum Analysis, so asto point out the possible relationship between radon and an environmental variable.

Dependence of radon concentration on pressure difference in a crawl-space

Radon concentration in a crawl space remained at the same level during autumn ( 756 Bq m-3 ) and inwinter ( 767 Bq m-3 ) because both air exchange rate and negative pressure (measured across thefoundation wall) increased after a installation of a new ventilation system in the crawl space. Inaddition, relative humidity and water content remained constant in the crawl space air during the sameperiod of time. Radon entry rate was explained by the pressure difference across the crawl space wallwith percentages of 51 % (winter) and 76 % (autumn).

Radon concentrations affected by different factors in two office buildings

In the study, the factors affecting concentrations of radon vertically lines were surveyed in twolarge office buildings. Integrated concentrations of radon were determined with alpha track etchfilms (2 months) and continuous monitoring (2-6 days) was carried out with Pylon AB-5equipment. The effective air exchange rates were analysed by the tracer gas method with aninfrared analyser and rates of air flows from vents were measured with a thermoanemometer.Pressure differences were measured with a manometer and temperature differences withthermoelements.

Karst geology, radon fluctuations, and implications for measurement and mitigation

Results of an investigation into factors contributing to elevated indoor radon concentrations insupposedly mitigated homes suggest that, in areas of extensive karst geological development,fluctuations in indoor radon concentrations may be extraordinary in magnitude, duration and seasonaloccurrence.

Teaching radon in the living environment school experiments with air, liquids, and solids

The contents of an Experimental Set are presented, providing all necessary implements for novelmethods to collect, concentrate, store and measure radon and radon decay products from harmless und ubiquitous sources of air, liquids and solids. A series of experiments is described to demonstrate the essential properties of radioactivity

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