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Sample records for modeling radon gas

  1. RAETRAD MODEL OF RADON GAS GENERATION, TRANSPORT, AND INDOOR ENTRY

    Science.gov (United States)

    The report describes the theoretical basis, implementation, and validation of the Radon Emanation and Transport into Dwellings (RAETRAD) model, a conceptual and mathematical approach for simulating radon (222Rn) gas generation and transport from soils and building foundations to ...

  2. Radon in soil gas

    International Nuclear Information System (INIS)

    Rector, H.E.

    1990-01-01

    This paper presents the results of a technology review conducted to identify and organize the range of options for measuring radon in soil gas as a means to evaluate radon exposure potential in buildings. The main focus of the review includes identifying the following: Measurement of objectives - the specific parameter(s) that each technology is designed to measure( e.g., soil gas concentration, flux density, etc.); Equipment needs -commercial availability of systems and/or components, specifications for fabricated components; Procedural information - documented elements of field and laboratory methodology and quality assurance; Underlying assumptions - conceptual and mathematical models utilized to convert analytical outcomes to estimators of radon. Basic technologies and field data were examined from a generic perspective (e.g., the common denominators of passive detectors, hollow sampling probes, flux monitors)( as well as specific configurations developed by individual investigators (e.g., sample volume, depth) to develop the basis for separating analytical uncertainties form sampling uncertainties

  3. Soil gas and radon entry into a simple test structure: Comparison of experimental and modelling results

    DEFF Research Database (Denmark)

    Andersen, C.E.; Søgaard-Hansen, J.; Majborn, B.

    1994-01-01

    A radon test structure has been established at a field site at Riso National Laboratory. Measurements have been made of soil gas entry rates, pressure couplings and radon depletion. The experimental results have been compared with results obtained from measured soil parameters and a two......-dimensional steady-state numerical model of Darcy flow and combined diffusive and advective transport of radon. For most probe locations, the calculated values of the pressure couplings and the radon depletion agree well with the measured values, thus verifying important elements of the Darcy flow approximation......, and the ability of the model to treat combined diffusive and advective transport of radon. However, the model gives an underestimation of the soil gas entry rate. Even if it is assumed that the soil has a permeability equal to the highest of the measured values, the model underestimates the soil gas entry rate...

  4. Dry radon gas generator

    International Nuclear Information System (INIS)

    Vandrish, G.

    1979-10-01

    A radon gas standard with a source strength of 120037 pCi capable of delivering 121 pCi of radon gas successively to a large number of cells has been developed. The absolute source strength has been calibrated against two radium solution standards and is accurate to 4 percent. A large number of cells (approxiiately 50) may be calibrated conveniently on a daily basis with appropriate corrections for sequential changes in the amount of gas delivered, and a correction for the growth of radon in the standard on successive days. Daily calibration of ten cells or less does not require these corrections. The standard is suitable for field use and the source emanation rate is stable over extreme temperatue and pressure ranges and over six months

  5. Radon chamber for soil gas detectors

    International Nuclear Information System (INIS)

    Andersson, P.

    1987-01-01

    Swedish Geological Co (SGAB) has designed and constructed a chamber for the calibration of detectors and instruments intended for the measurement of radon-222 in soil gas. In the chamber radon detectors may be exposed in a model environment which simulates ground conditions with respect to radon concentration, temperature and humidity. Also included in the research project is the development of methods for calibration procedures, together with test measurements. In general, these measurements indicate that the radon detectors tested are sufficiently accurate and reliable for radon measurements in Swedish soils if they are calibrated in an environment which simulates ground conditions. (orig./HP)

  6. ERRICCA radon model intercomparison exercise

    DEFF Research Database (Denmark)

    Andersen, C.E.; Albarracín, D.; Csige, I.

    1999-01-01

    -state diffusive radon profiles in dry and wet soils, (2) steady-state entry of soil gas and radon into a house, (3) time-dependent radon exhalation from abuilding-material sample. These cases cover features such as: soil heterogeneity, anisotropy, 3D-effects, time dependency, combined advective and diffusive......, still remain. All in all, it seems that the exercise has served its purpose and stimulated improvements relating to the quality of numerical modelling of radon transport. To maintain a high quality of modelling, it is recommendedthat additional exercises are carried out....

  7. Radon gas detector

    International Nuclear Information System (INIS)

    Madnick, P.A.; Sherwood, R.W.

    1990-01-01

    This patent describes a radon gas detector. It comprises: a housing having an interior chamber, the interior chamber being completely closed to ambient light, the interior chamber being divided into an environment connecting chamber and a radiation ascertaining chamber; radiation sensitive means mounted between the environment connecting chamber and the radiation ascertaining chamber; air movement means mounted in connection with the environment connecting chamber. The air movement means for moving ambient air through the environment connecting chamber; electronic means for detecting radiation within the air which is passing through the environment connecting chamber. The electronic means also including radiation counting means. The electronic means producing an output based on the type and quantity of radiation in the environment connecting chamber; and display electronics for receiving the output and displaying accordingly a display representative of the amount and type of radiation located within the environment connecting chamber and hence within the ambient air

  8. ERRICCA radon model intercomparison exercise

    International Nuclear Information System (INIS)

    Andersen, C.E.; Albarracin, D.; Csige, I.; Graaf, E.R. van der; Jiranek, M.; Rehs, B.; Svoboda, Z.; Toro, L.

    1999-04-01

    Numerical models based on finite-difference or finite-element methods are used by various research groups in studies of radon-222 transport through soil and building materials. Applications range from design of radon remediation systems to more fundamental studies of radon transport. To ascertain that results obtained with these models are of good quality, it is necessary that such models are tested. This document reports on a benchmark test organized by the EU project ERRICCA: European Research into Radon in Construction Concerted Action. The test comprises the following cases: 1) Steady-state diffusive radon profiles in dry and wet soils, 2) steady-state entry of soil gas and radon into a house, 3) time-dependent radon exhalation from a building-material sample. These cases cover features such as: soil heterogeneity, anisotropy, 3D-effects, time dependency, combined advective and diffusive transport of radon, flux calculations, and partitioning of radon between air and water in soil pores. Seven groups participated in the intercomparison. All groups submitted results without knowing the results of others. For these results, relatively large group-to-group discrepancies were observed. Because of this, all groups scrutinized their computations (once more) and engaged in follow-up discussions with others. During this debugging process, problems were indeed identified (and eliminated). The accordingly revised results were in better agreement than those reported initially. Some discrepancies, however, still remain. All in all, it seems that the exercise has served its purpose and stimulated improvements relating to the quality of numerical modelling of radon transport. To maintain a high quality of modelling, it is recommended that additional exercises are carried out. (au)

  9. Radon gas measurement in Corum

    International Nuclear Information System (INIS)

    Uzbey, S.; Celebi, N.

    2009-01-01

    The existence of the natural radioactive sources in earth's crust which has long half-life and the degradation products of these in the environmental medium such as earth, rocks, foods, water, air, forms the basis of radiation which people are exposed to. Radon is the unique radioactive gas in the nature and it is made up of radium which is the result of uranium degradation. It is necessary to determine the radon concentration because of the difference in the concentration of uranium existence in different places. TAEK (Turkish Atomic Energy Authority) allows 400 Bq/m 3 of radon concentration at houses, 1000 Bq/m 3 at offices per year. In this attempt, government buildings, houses and offices were determined as the sampling places in Corum city center and towns to represent Corum. While disposing the radon measuring detectors, places which are close to the ground level were preferred. 74 radon detectors were left in those places for 60 days and in the end the detectors were collected while discontinuing the connection of environment and they were assessed. According to the results, the average radon gas concentration in 14 government buildings is 71,71 Bq/m 3 , in 15 offices 32,26 Bq/m 3 and at houses 42,34 Bq/m 3 .

  10. MODEL RADIOACTIVE RADON DECAY

    Directory of Open Access Journals (Sweden)

    R.I. Parovik

    2012-06-01

    Full Text Available In a model of radioactive decay of radon in the sample (222Rn. The model assumes that the probability of the decay of radon and its half-life depends on the fractal properties of the geological environment. The dependencies of the decay parameters of the fractal dimension of the medium.

  11. Membrane barriers for radon gas flow restrictions

    International Nuclear Information System (INIS)

    Archibald, J.F.

    1984-08-01

    Research was performed to assess the feasibility of barrier membrane substances, for use within mining or associated high risk environments, in restricting the diffusion transport of radon gas quantities. Specific tests were conducted to determine permeability parameters of a variety of membrane materials with reference to radon flow capabilities. Tests were conducted both within laboratory and in-situ emanation environments where concentrations and diffusion flows of radon gas were known to exist. Equilibrium radon gas concentrations were monitored in initially radon-free chambers adjacent to gas sources, but separated by specified membrane substances. Membrane barrier effectiveness was demonstrated to result in reduced emanation concentrations of radon gas within the sampling chamber atmosphere. Minimum gas concentrations were evidenced where the barrier membrane material was shown to exhibit lowest radon permeability characteristics

  12. Modeling of indoor radon

    International Nuclear Information System (INIS)

    Paschoa, A.S.

    1990-01-01

    This paper reports on models for radon, which are developed not only to describe the behavior of radon and daughters since the moment that radon is created in natural sources by the alpha decay of 226 Ra up to the point that doses to humans are estimated based on the inhalation of radon and its progeny. The objective of a model should be determinant in defining the model structure and boundaries. Modeling indoors radon is particularly useful when the 226 Ra concentration in building materials and soils can be known before a house will be built with such 226 Ra bearing materials and over 226 Ra rich soils. The reported concentrations of 226 Ra in building materials range from 0.3 Bq · kg -1 in wood to about 2.6 x 10 3 Bq · kg -1 in aerated concrete based on alum shale. 30 In addition, when a house is built on a soil containing a high 226 Ra concentration, radon exhalation from the soil contributes to increase radon concentration indoors. The reported radon exhalation from soils range from 3.4 Bq · m -2 · s -1 in latosolic soil from Osaka, Japan to about 53 mBq · m -2 · s -1 in chernozemic soil from Illinois

  13. Radon gas as a tracer for volcanic processes

    International Nuclear Information System (INIS)

    Thomas, D.M.

    1990-01-01

    Radon emissions from volcanic systems have been under investigation for several decades. Soil gas and groundwater radon activities have been used to map faults and to characterize geothermal systems, and measurements of atmospheric radon and radon daughter concentrations have been used to estimate the volume of magma chambers feeding active eruptions. Several studies have also shown that temporal variations in radon concentration have been associated with the onset of volcanic eruptions or changes in the rates or character of an eruption. Some of these studies have been able to clearly define the cause of the radon anomalies but others have proposed models of radon emission and transport that are not well supported by the known physical and chemical processes that occur in a volcanic system. In order to better characterize the processes that control radon activities in volcanic systems, it is recommended that future radon monitoring programs attempt to maintain continuous recording of radon activities; individual radon measurements should be made over the shortest time intervals possible that are consistent with acceptable counting statistics and geophysical, meteorological, and hydrological parameters should be measured in order to better define the physical processes that affect radon activities in volcanic systems. (author). 63 refs

  14. Radon diagnostics and tracer gas measurements

    International Nuclear Information System (INIS)

    Jilek, K.; Brabec, M.

    2004-01-01

    An outline is presented of the tracer gas technique, which is used for continuous measurements of air ventilation rate (generally time-varying) and for simultaneous estimation of air ventilation rate and radon entry rate, and some of its limitations are discussed. The performance of this technique in the calculation of the air ventilation rate is demonstrated on real data from routine measurements. The potential for air ventilation rate estimation based on radon measurements only is discussed. A practical application is described of the tracer gas technique to a simultaneous estimation of the air ventilation rate and radon entry rate in a real house where the effectiveness of radon remedy was tested. The following main advantages of the CO tracer gas techniques are stressed: (i) The averaging method continuous determination of the ventilation rate with good accuracy (≤ 20 %). (ii) The newly presented and verified method based on simultaneous measurements of radon concentration and CO gas concentration enables separate continuous measurements of the radon entry rate and ventilation rate. The results of comparative measurements performed with the aim to estimate the inaccuracy in determination of radon entry rate showed acceptable and good agreement up to approximately 10 %. The results of comparative measurements performed with the aim to estimate the mutual commensuration of the method to the determination of the ventilation rate confirmed the expected unreliability the two parametric non-linear regression method, which is the most frequently used method in radon diagnostic in the Czech Republic

  15. Soil gas radon response to environmental and soil physics variables

    International Nuclear Information System (INIS)

    Thomas, D.M.; Chen, C.; Holford, D.

    1991-01-01

    During the last three years a field study of soil gas radon activities conducted at Poamoho, Oahu, has shown that the primary environmental variables that control radon transport in shallow tropical soils are synoptic and diurnal barometric pressure changes and soil moisture levels. Barometric pressure changes drive advective transport and mixing of soil gas with atmospheric air; soil moisture appears to control soil porosity and permeability to enhance or inhibit advective and diffusive radon transport. An advective barrier test/control experiment has shown that advective exchange of soil gas and air may account for a substantial proportion of the radon loss from shallow soils but does not significantly affect radon activities at depths greater than 2.3 m. An irrigation test/control experiment also suggests that, at soil moisture levels approaching field capacity, saturation of soil macroporosity can halt all advective transport of radon and limit diffusive mobility to that occurring in the liquid phase. The results of the authors field study have been used to further refine and extend a numerical model, RN3D, that has been developed by Pacific Northwest Laboratories to simulate subsurface transport of radon. The field data have allowed them to accurately simulate the steady state soil gas radon profile at their field site and to track transient radon activities under the influence of barometric pressure changes and in response to changes in soil permeability that result from variations in soil moisture levels. Further work is continuing on the model to enable it to properly account for the relative effects of advective transport of soil gas through cracks and diffusive mobility in the bulk soils

  16. Comparison of calculated and measured soil-gas radon concentration and radon exhalation rate

    International Nuclear Information System (INIS)

    Neznal, Martin; Neznal, Matej; Jiranek, Martin

    2000-01-01

    The computer model RADON2D for WINDOWS, which makes it possible to estimate the radon exhalation rate from the ground surface and the distribution of soil-gas radon concentration, was tested using a large set of experimental data coming from four reference areas located in regions with different geological structure. A good agreement between calculated and experimental data was observed. In the majority of cases, a correct description of the real situation was obtained using non-modified experimental input data. (author)

  17. Observation of radon content in soil gas

    International Nuclear Information System (INIS)

    Mino, Kazuo; Nishimura, Susumu

    1979-01-01

    For earthquake prediction, precursory phenomena before the large earthquakes have been investigated in many countries. In China and some other places, they made a success of predictions of the large earthquakes by catching precursory phenomena. Variation of Radon content of underground gas and water is also one of those phenomena. In our country, the decrease of Radon content was observed several days before the large earthquake which occured near Izu Peninsula on January, 14, 1978. We also begin to observe variation of Radon content of underground gas. The purpose of our observation is a study on the Radon gas content before and after earthquakes. According to the results of the test investigation, the change of atmospheric pressure is mutually related with variation of Radon content in soil gas. Effect of atmospheric pressure is about one Eman, which is significant value comparison with the change, before the large earthquake, a few or several Emans. But, when correction of atmospheric pressure's effect was done, the change of Radon content maybe decrease 5/100 Emans. Above result tells the possibility of detecting the precursor of large earthquake, if Radon content change was over a few Emans. (author)

  18. Measurements of radon in soil gas

    International Nuclear Information System (INIS)

    Paschuk, Sergei A.; Correa, Janine Nicolosi; Schelin, Hugo R.; Barbosa, Laercio; Sadula, Tatyana; Matsuzaki, Cristiana A.

    2009-01-01

    Full text: After the decades of systematic and numerous studies performed at different countries of the World, it has been concluded that radon as well as its progeny is the main cause of lung cancer. It is well known that more than 50% of the effective annual radiation dose received by a human being is related to the radon and its progenies. Among the principle mechanisms that bring the radon inside the dwelling is the soil exhalation as well as exhalation and release from the water. Radon concentration in the soil and its transport (emanation, diffusion, advection and adsorption) to the surface depends on different physical, geological and ambient parameters such as the geology of the area, geochemical composition of the soil, its porosity and permeability, grain size, soil humidity, bottom sediments and inputs from streams, temperature, atmospheric pressure, etc. Since the main part of indoor radon originates in the soil, the measurements of radon concentration in soil gas have to be considered as an important tool and indicator of probable high levels of radon inside the dwellings. Present work describes the radon in soil gas measurements performed during the last two years in cooperation between the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR), the Nuclear Technology Development Center (CDTN) and the Institute of Radiation Protection and Dosimetry (IRD) from the Brazilian Nuclear Energy Commission (CNEN). Following previously concluded measurements of radon concentration in dwellings and the measurements of 222 Rn activity in drinking water collected at artesian bores of Curitiba urban area, present step of activities has been dedicated to measurements of radon concentration in soil gas. Experimental setup was based on the Professional Radon Monitor (ALPHA GUARD) connected to specially developed for such measurements Soil Gas Probe through the air pump and filter system. The equipment was adjusted with air flow of 0

  19. Radon, gas geochemistry, groundwater, and earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    King, Chi-Yu [Power Reactor and Nuclear Fuel Development Corp., Tono Geoscience Center, Toki, Gifu (Japan)

    1998-12-31

    Radon monitoring in groundwater, soil air, and atmosphere has been continued in many seismic areas of the world for earthquake-prediction and active-fault studies. Some recent measurements of radon and other geochemical and hydrological parameters have been made for sufficiently long periods, with reliable instruments, and together with measurements of meteorological variables and solid-earth tides. The resultant data are useful in better distinguishing earthquake-related changes from various background noises. Some measurements have been carried out in areas where other geophysical measurements are being made also. Comparative studies of various kinds of geophysical data are helpful in ascertaining the reality of the earthquake-related and fault-related anomalies and in understanding the underlying mechanisms. Spatial anomalies of radon and other terrestrial gasses have been observed for many active faults. Such observations indicate that gas concentrations are very much site dependent, particularly on fault zones where terrestrial fluids may move vertically. Temporal anomalies have been reliably observed before and after some recent earthquakes, including the 1995 Kobe earthquake, and the general pattern of anomaly occurrence remains the same as observed before: They are recorded at only relatively few sensitive sites, which can be at much larger distances than expected from existing earthquake-source models. The sensitivity of a sensitive site is also found to be changeable with time. These results clearly show the inadequacy of the existing dilatancy-fluid diffusion and elastic-dislocation models for earthquake sources to explain earthquake-related geochemical and geophysical changes recorded at large distances. (J.P.N.)

  20. Radon in soil gas in Kosovo.

    Science.gov (United States)

    Kikaj, Dafina; Jeran, Zvonka; Bahtijari, Meleq; Stegnar, Peter

    2016-11-01

    An assessment of the radiological situation due to exposure to radon and gamma emitting radionuclides was conducted in southern Kosovo. This study deals with sources of radon in soil gas. A long-term study of radon concentrations in the soil gas was carried out using the SSNTDs (CR-39) at 21 different locations in the Sharr-Korabi zone. The detectors were exposed for an extended period of time, including at least three seasonal periods in a year and the sampling locations were chosen with respect to lithology. In order to determine the concentration of the natural radioactive elements 238 U and 226 Ra, as a precursor of 222 Rn, soil samples were collected from each measuring point from a depth of 0.8 m, and measured by gamma spectrometry. The levels (Bq kg -1 ) of naturally occurring radionuclides and levels (kBq m -3 ) of radon in soil gas obtained at a depth 0.8 m of soil were: 21-53 for 226 Ra, 22-160 for 238 U and 0.295-32 for 222 Rn. With respect to lithology, the highest value for 238 U and 226 Ra were found in limestone and the highest value for 222 Rn was found in metamorphic rocks. In addition, the results showed seasonal variations of the measured soil gas radon concentrations with maximum concentration in the spring months. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Rehabilitation Measures against radon gas entry

    International Nuclear Information System (INIS)

    Frutos Vazquez, Borja; Olaya Adan, Manuel; Esteban Saiz, Jose Luis

    2011-01-01

    Radon gas is a pathological agent for inhabitants of buildings where it is present. Due to its origin in uranium decay chain, it bears radioactive effects that inside human body lead to higher risks of developing lung cancer. It comes from soils containing granite masses or other substrates containing uranium. It enters through common material used in constructions, such as concrete ground slabs, basement walls, etc. In order to avoid such gas immission into inhabited rooms, several measurements cab be considered for existing buildings. This study intends to show the results obtained for radon reductions by means of different constructive solutions, already designed and executed so as to stop radon gas immission into a prototype building constructed for this specific purpose

  2. Application of a radon model to explain indoor radon levels in a Swedish house

    International Nuclear Information System (INIS)

    Font, LL.; Baixeras, C.; Joensson, G.; Enge, W.; Ghose, R.

    1999-01-01

    Radon entry from soil into indoor air and its accumulation indoors depends on several parameters, the values of which normally depend on the specific characteristics of the site. The effect of a specific parameter is often difficult to explain from the result of indoor radon measurements only. The adaptation of the RAGENA (RAdon Generation, ENtry and Accumulation indoors) model to a Swedish house to characterise indoor radon levels and the relative importance of the different radon sources and entry mechanisms is presented. The building is a single-zone house with a naturally-ventilated crawl space in one part and a concrete floor in another part, leading to different radon levels in the two parts of the building. The soil under the house is moraine, which is relatively permeable to radon gas. The house is naturally-ventilated. The mean indoor radon concentration values measured with nuclear track detectors in the crawl-space and concrete parts of the house are respectively 75±30 and 200±80 Bq m -3 . Results of the model adaptation to the house indicate that soil constitutes the most relevant radon source in both parts of the house. The radon concentration values predicted by the model indoors fall into the same range as the experimental results

  3. Soil and gas and radon entry potentials for substructure surfaces

    International Nuclear Information System (INIS)

    Harrison, J.; Sextro, R.G.

    1990-01-01

    This paper reports on measurement techniques and parameters that describe the potential for areas of a building substructure to have high soil gas and radon entry rates which have been developed. Flows and pressures measured at test holes in substructure surfaces while the substructure was intentionally depressurized were used in a highly simplified electrical circuit to model the substructure/soil network. Data from four New Jersey houses indicate that the soil was a factor of two to six times more resistant to soil gas flow than substructure surfaces, concrete slab floors, including perimeter gaps, cracks, and other penetrations, were approximately five times more resistant to soil gas movement than hollow block walls, and radon entry potentials were highest for slab floors. These indices of entry potential may be useful for characterizing the relative leakiness of below-grade substructure surfaces and for determining the selection and placement of radon control systems

  4. The use of soil gas as radon source in radon chambers

    International Nuclear Information System (INIS)

    Al-Azmi, Darwish

    2009-01-01

    A procedure is described in which soil gas is utilized as an alternative to the 226 Ra source for the supply of the radon gas required to fill a radon chamber where radon-measuring devices are calibrated. The procedure offers opportunities to vary the radon concentration within the chamber around an average value of about 500 Bq/m 3 , which is considered to be sufficient for calibrating indoor radon detectors. The procedure is simple and the radon source does not require radiation protection certification (for import and/or use), unlike the commercially produced standard radioactive ( 226 Ra) sources.

  5. Express method and radon gas measurement detector

    International Nuclear Information System (INIS)

    Khajdarov, R.A.; Khajdarov, R.R.

    2004-01-01

    The purpose of this work was to improve the activated charcoal adsorption method. The detector consisted of an electronic unit (200 mm x 180 mm x 80 mm) and a scintillation cell (a tube 200 mm long, 60 mm diam.). The electronic unit contained a power supply, amplifier, discriminator, timer, counter and indicator. The scintillation cell contained a zinc sulfide scintillator, photomultiplier, preamplifier, high voltage power supply and a 200 ml chamber above the scintillator. This chamber was intended to situate activated carbon fibrous absorber and air compressor. In this method, air is drawn through a filter to remove radon decay products and then through the activated carbon cloth by using a compressor. Sampling takes between 5 and 15 minutes. After the sampling, the cloth is heated for 5-10 sec up to 200-250 deg C by electric current passing through the fiber. Radon gas evaporates from the cloth and the device detects scintillation pulses. Owing to a high radon preconcentration factor (by adsorption of radon on the activated carbon cloth from 50-150 L of air of and evaporation into the small volume of the chamber), the detection limit of the method is 2-4 Bq/m 3 . Since the distance between the filter, cloth and scintillator is over 80 mm, the detector only measures radiation from radon without interference from the radon decay products, remaining in the filter and cloth

  6. Ground-truthing predicted indoor radon concentrations by using soil-gas radon measurements

    International Nuclear Information System (INIS)

    Reimer, G.M.

    2001-01-01

    Predicting indoor radon potential has gained in importance even as the national radon programs began to wane. A cooperative study to produce radon potential maps was conducted by the Environmental Protection Agency (EPA), U.S. Geological Survey (USGS), Department of Energy (DOE), and Lawrence Berkeley Laboratory (LBL) with the latter taking the lead role. A county-wide predictive model based dominantly on the National Uranium Resource Evaluation (NURE) aerorad data and secondly on geology, both small-scale data bases was developed. However, that model breaks down in counties of complex geology and does not provide a means to evaluate the potential of an individual home or building site. Soil-gas radon measurements on a large scale are currently shown to provide information for estimating radon potential at individual sites sort out the complex geology so that the small-scale prediction index can be validated. An example from Frederick County, Maryland indicates a positive correlation between indoor measurements and soil-gas data. The method does not rely on a single measurement, but a series that incorporate seasonal and meteorological considerations. (author)

  7. Entry of soil gas and radon into houses

    International Nuclear Information System (INIS)

    Andersen, C.E.

    1992-04-01

    Entry of soil gas and radon into houses has been investigated by experiments conducted at radon test structures and numerical or analytical modelling. The numerical model solves the steady-state equations for Darcy flow of soil-gas and combined diffusive and advective transport of radon. Model calculations were compared with results from field experiments conducted at Risoe National Laboratory, and it was found that there was good agreement between measured and modelled pressure coupling and radon concentration profiles. Discrepancies regarding absolute values of soil-gas entry rates and radon concentrations were observed. The numerical model has been used to study the importance of soil and building related factors on radon entry rates into slab-on-grade houses. It was found that, for a house with a 3 mm perimeter crack along the floor-wall joint, the entry was mainly determined by the soil permeability and building related factors such as house depressurization and presence of a capillary breaking layer of gravel below the slab. In a house with a bare soil floor, the diffusivity of the soil was found to be of principal importance for the entry rate even for moderate permeabilities. An analytical model was developed for the purpose of studying soil-gas entry rates into houses in response to non-static driving forces. It is based on the analogy between a 'buried drain' and a basement house with a perimeter crack. The structure was depressurized sinusoidally in time and the frequency dependent pressure couplings were measured. There was fairly good agreement between theoretical and experimental results. (LN) (26 tabs., 30 ills., 66 refs.)

  8. Models of radon entry: A review

    International Nuclear Information System (INIS)

    Gadgil, A.J.

    1991-08-01

    This paper reviews existing models of radon entry into houses. The primary mechanism of radon entry in houses with high indoor concentrations is, in most cases, convective entry of radon bearing soil-gas from the surrounding soil. The driving force for this convective entry is the small indoor-outdoor pressure difference arising from the stack effect and other causes. Entry points for the soil-gas generally are the cracks or gaps in the building substructure, or though other parts of the building shell in direct contact with the soil, although entry may also occur by flow though permeable concrete or cinder block walls of the substructure. Models using analytical solutions to idealized geometrical configurations with simplified boundary conditions obtain analytical tractability of equations to be solved at the cost of severe approximations; their strength is in the insights they offer with their solutions. Models based on lumped parameters attempt to characterize the significant physical behavioral characteristics of the soil-gas and radon flow. When realistic approximations are desired for the boundary conditions and terms in the governing equations, numerical models must be used; these are usually based on finite difference or finite element solutions to the governing equations. Limited data are now available for experimental verification of model predictions. The models are briefly reviewed and their strengths and limitations are discussed

  9. A comparison of contemporary and retrospective radon gas measurements in high radon dwellings in Ireland

    International Nuclear Information System (INIS)

    Kelleher, K.; McLaughlin, J.P.; Fenton, D.; Colgan, P.A.

    2006-01-01

    Little correlations has been found between contemporary radon gas measurements made in the past and retrospective radon gas measurements in Irish dwellings. This would suggest that these two techniques would result in two significantly different cumulative radon exposure estimates. Contemporary radon gas measurements made a few years apart in the same room of a dwelling were found to be significantly different. None of these differences could be explained by known changes to the rooms themselves., such ventilation or structural alterations to the room. This highlights the limitations of the contemporary radon gas measurements as a surrogate measurement for use in residential radon epidemiology. The contemporary radon gas measurements made by the Radiological Protection Institute of Ireland (R.P.I.I.) and University College of Dublin (U.C.D.) do not cover the same exposure period as the retrospective estimates and so the accuracy of the retrospective measurements cannot be demonstrated. A weak correlation can be seen between the retrospective radon gas estimates and a combination of the two contemporary radon gas estimates. It is not unreasonable to expect improvement in the correlation if further contemporary radon gas measurements were made in these rooms. (N.C.)

  10. Intercomparison of radon gas detectors 1999 and 2000 at PSI

    International Nuclear Information System (INIS)

    Schuler, Christoph; Butterweck, Gernot

    2000-10-01

    This report describes the results of two radon intercomparison exercises performed by the Reference Laboratory for Radon Gas Activity Concentration Measurements at Paul Scherrer Institut from Sep 9th to Oct 6th, 1999, and from March 21st to 28th, 2000. Radon gas detectors and instruments were exposed in the PSI Radon Chamber in reference atmospheres to 1060 kBqhm -3 radon gas exposure at an average radon gas concentration of 6400 Bqm -3 and to 2050 kBqhm -3 radon gas exposure at an average radon gas concentration of 12500 Bqm -3 , respectively. These intercomparison exercises determined the performance of electret ionisation chambers, track etch detectors and measuring instruments at high humidity (1999 Intercomparison Exercise) and at a high radon gas exposure (2000 Intercomparison Exercise). In the 1999 Intercomparison Exercise, electret ionisation chambers revealed an influence on high humidity. This effect may be due to impurities on a microscopic scale on the electrets of these detectors. With few exceptions, in both the 1999 and the 2000 Radon Intercomparison Exercise the deviations of the measurement results to the reference radon gas concentration values were less than 15% (traceability criterion) and the standard deviation of the results of five detectors less than 15% (reproducibility criterion). (author) [de

  11. Plastic-bag radon gas monitor and survey results

    International Nuclear Information System (INIS)

    Torri, G.

    1990-01-01

    The Plastic-bag radon monitor used in the Italian National Survey is described. The choice of this radon gas sampler has been determined by the peculiarity of the italian environmental monitoring program, which is carried out by several different regional laboratories. Results obtained in the past using this radon monitoring device are also reported. (author). 8 refs, 7 figs

  12. Radon

    Energy Technology Data Exchange (ETDEWEB)

    Weigel, F [Muenchen Univ. (Germany, F.R.). Inst. fuer Anorganische Chemie

    1978-09-01

    The noble gas radon, formerly called emanation, was discovered a few years after radium. /sup 222/Rn, the longest-lived isotope, has a half-life of 3,82 days. This half life is so short that the experimental techniques available at present (1978) are not sufficient for a characterization of defined radon compounds, even though there are definite indications for the existence of such compounds, and one may expect such radon compounds to be even more stable than the numerous known xenon compounds. - The radon isotopes /sup 219/Rn (Actinon), /sup 220/Rn (Thoron), and /sup 222/Rn (Radon) occur in nature despite their rather short half-lives, because they are continously generated from their mothers /sup 223/Ra, /sup 224/Ra, and /sup 226/Ra, which are in secular equilibrium with long-lived isotopes /sup 235/U, /sup 238/U, and /sup 232/Th, and are in turn continously formed from these long-lived isotopes. Since the radon isotopes are gases, they enter the atmosphere and are carried for long distances with air currents. - Because radon is so short-lived, its practical applications are rather limited. For medical applications, small sealed glass tubes filled with radon are used as radiation sources after the radon has decayed, because the whole series of Po-, Bi-, and Pb-isotopes of the radium decay chain are formed, whose penetrating radiation is useful for therapy. When solids are spiked with Ra isotopes, radon is evolved at a constant rate. On heating such solids, phase transitions show up by sudden increased radon evolution (Hahn's emanation method). - On the basis of nuclear theoretical calculations, there is hardly a chance for the discovery of a long-lived radon species. Therefore, major progress in radon chemistry is hardly to be expected in the near future.

  13. Application of a radon model to explain indoor radon levels in a Swedish house

    CERN Document Server

    Font, L; Jönsson, G; Enge, W; Ghose, R

    1999-01-01

    Radon entry from soil into indoor air and its accumulation indoors depends on several parameters, the values of which normally depend on the specific characteristics of the site. The effect of a specific parameter is often difficult to explain from the result of indoor radon measurements only. The adaptation of the RAGENA (RAdon Generation, ENtry and Accumulation indoors) model to a Swedish house to characterise indoor radon levels and the relative importance of the different radon sources and entry mechanisms is presented. The building is a single-zone house with a naturally-ventilated crawl space in one part and a concrete floor in another part, leading to different radon levels in the two parts of the building. The soil under the house is moraine, which is relatively permeable to radon gas. The house is naturally-ventilated. The mean indoor radon concentration values measured with nuclear track detectors in the crawl-space and concrete parts of the house are respectively 75+-30 and 200+-80 Bq m sup - sup 3...

  14. A radon progeny deposition model

    International Nuclear Information System (INIS)

    Rielage, Keith; Elliott, Steven R.; Hime, Andrew; Guiseppe, Vincent E.; Westerdale, S.

    2010-01-01

    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly 222 Rn) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of 210 Pb on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.

  15. A Radon Progeny Deposition Model

    International Nuclear Information System (INIS)

    Guiseppe, V. E.; Elliott, S. R.; Hime, A.; Rielage, K.; Westerdale, S.

    2011-01-01

    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly 222 Rn) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of 210 Pb on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.

  16. Radon gas in oil and natural gas production facilities

    International Nuclear Information System (INIS)

    Chandler, W.P.

    1994-01-01

    Radon gas is a naturally occurring radionuclide that can be found in some oil and natural gas production facilities, either as a contaminant in a natural gas stream or derived from Radium dissolved in formation waters. The gas itself is not normally a health hazard, but it's decay products, which can be concentrated by plate-out or deposition as a scale in process equipment, can be a health hazard for maintenance personnel. To evaluate possible health hazards, it is necessary to monitor for naturally occurring radioactive materials (NORM) in the gas stream and in the formation water. If Radon and/or Radium is found, a monitoring programme should be initiated to comply with National or State requirements. In some instances, it has been found necessary to dispose of silt and scale materials as low level radioactive waste. 8 refs

  17. Modelling of radon transport in porous media

    NARCIS (Netherlands)

    van der Graaf, E.R.; de Meijer, R.J.; Katase, A; Shimo, M

    1998-01-01

    This paper aims to describe the state of the art of modelling radon transport in soil on basis of multiphase radon transport equations. Emphasis is given to methods to obtain a consistent set of input parameters needed For such models. Model-measurement comparisons with the KVI radon transport

  18. Intercomparison of radon gas detectors 1997 at PSI

    International Nuclear Information System (INIS)

    Schuler, Christoph; Butterweck-Dempewolf, Gernot

    1998-05-01

    Between Nov 14 and Nov 20, 1997, the Reference Laboratory for Radon Gas Activity Concentration Measurements at Paul Scherrer Institut performed the 1997 Radon Intercomparison Exercise. Radon gas detectors and instruments were exposed in the PSI Radon Chamber during seven days in a reference atmosphere with an average radon gas concentration of 3860 Bqm -3 . The majority of the participants at this intercomparison were Swiss Radon Gas Measurement Laboratories acknowledged by the Swiss Federal Office for Health. Criteria for this acknowledgement are a deviation of the measurement results to the reference value below 15% (traceability criterion) and a standard deviation of the mean of five detector measurement results below 15% (reproducibility criterion). With the exception of three participants, the results of electret ionisation chambers, track etch detectors and measuring instruments fulfilled the demanded traceability and reproducibility criteria. (author)

  19. Assessment of indoor radon gas concentration change of college

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hoon Hee; Jeong, Eui Hwan; Kim, Hak Jae; Lyu, Kang Yeul [Dept. of of Radiological Technology, Shingu College, Seongnam (Korea, Republic of); Lee, Ju Young [Dept. of Radiological Technology, Songho College, Hoengseong (Korea, Republic of)

    2017-03-15

    The purpose of this study was to assess the impact by comparing the concentration of indoor radon and look for ways to lower the concentration of indoor radon gas measurements of three variables, the year of completion, volume of the building and ventilation. Measurement target is six classrooms on the sixth floor of building that was constructed in 1973 and was extended in 2011. Selected classroom's volume is different. Four classrooms were selected to compare the radon concentration in accordance with the year of completion, Classrooms that is same year of completion were selected to compare the radon concentration in accordance with the volume, six classroom was performed closure and ventilation to compare radon concentration according to ventilation. Radon concentrations in accordance with the year of building completion showed a high concentration of radon in a building recently built. Also, Radon concentration in volume is high the smaller the volume. Radon concentration change according to ventilation showed a reduction of about 80% when the ventilation than during closing. Especially, The radon concentrations were high detected while the recently year of building completion and the smaller volume. Ventilation of the three variables is considered that can be expected to exposure reduction effect by radon affecting the greatest radon concentration reduction.

  20. Assessment of indoor radon gas concentration change of college

    International Nuclear Information System (INIS)

    Park, Hoon Hee; Jeong, Eui Hwan; Kim, Hak Jae; Lyu, Kang Yeul; Lee, Ju Young

    2017-01-01

    The purpose of this study was to assess the impact by comparing the concentration of indoor radon and look for ways to lower the concentration of indoor radon gas measurements of three variables, the year of completion, volume of the building and ventilation. Measurement target is six classrooms on the sixth floor of building that was constructed in 1973 and was extended in 2011. Selected classroom's volume is different. Four classrooms were selected to compare the radon concentration in accordance with the year of completion, Classrooms that is same year of completion were selected to compare the radon concentration in accordance with the volume, six classroom was performed closure and ventilation to compare radon concentration according to ventilation. Radon concentrations in accordance with the year of building completion showed a high concentration of radon in a building recently built. Also, Radon concentration in volume is high the smaller the volume. Radon concentration change according to ventilation showed a reduction of about 80% when the ventilation than during closing. Especially, The radon concentrations were high detected while the recently year of building completion and the smaller volume. Ventilation of the three variables is considered that can be expected to exposure reduction effect by radon affecting the greatest radon concentration reduction

  1. Application of the can technique and radon gas analyzer for radon exhalation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Fazal-ur-Rehman E-mail: fazalr@kfupm.edu.sa; Al-Jarallah, M.I.; Musazay, M.S.; Abu-Jarad, F

    2003-12-01

    A passive 'can technique' and an active radon gas analyzer with an emanation container were applied for radon exhalation rate measurements from different construction materials, viz. five marble seven ceramic and 100 granite tiles used in Saudi Arabia. The marble and ceramic tiles did not show detectable radon exhalation using the active radon gas analyzer system. However the granite tiles showed relatively high radon exhalations, indicating a relatively high uranium content. A comparison of the radon exhalation rates measured by the two techniques showed a linear correlation coefficient of 0.57. The radon exhalation rates from the granites varied from 0.02 to 6.58 Bq m{sup -2} h{sup -1} with an average of 1.35{+-}1.40 Bq m{sup -2} h{sup -1}. The geometric mean and the geometric standard deviation of the frequency distribution were found to be 0.80 and 3.1, respectively. The track density found on the nuclear track detectors in the can technique exposed to the granites, having high exhalation rates, varied linearly with exposure time with a linear correlation coefficient of 0.99. This experimental finding agrees with the theoretical prediction. The can technique showed sensitivity to low radon exhalation rates from ceramic, marble and some granite over a period of 2 months, which were not detectable by the active radon gas analyzer system. The reproducibility of data with both measuring techniques was found to be within a 7% deviation.

  2. Soil gas radon and thoron measurements in some Venezuelan oilfields

    International Nuclear Information System (INIS)

    Fernandez, Daniel Palacios; Yininber Avila; Teixeira, Diana; Sajo-Bohus, Laszlo; Greaves, Eduardo; Barros, Haydn; Fusella, Emidio; Salas, Johnny; Fernandez, Guillermo; Bolivar, Manuel; Regalado, Jimmy

    2016-01-01

    Radon and thoron concentrations in soil gas were studied in some Venezuelan oilfields using passive and active methods. In some cases, investigations indicated a strong correlation between oil production areas and the intensity of radon signals, while in others a decrease in radon concentration was observed. This behavior was explained on the basis of different geological structures of the associated reservoir traps. Geological faults associated with petroleum systems were well recognized by the radon and thoron anomalies. Possible conduits and sources responsible for the occurrence of natural gas in a river and in an aquifer were identified and localized. (author)

  3. Radon transport in fractured soil. Laboratory experiments and modelling

    International Nuclear Information System (INIS)

    Hoff, A.

    1997-10-01

    Radon (Rn-222) transport in fractured soil has been investigated by laboratory experiments and by modelling. Radon transport experiments have been performed with two sand columns (homogeneous and inhomogeneous) and one undisturbed clayey till column containing a net of preferential flow paths (root holes). A numerical model (the finite-element model FRACTRAN) and an analytic model (a pinhole model) have been applied in simulations if soil gas and radon transport in fractured soil. Experiments and model calculations are included in a discussion of radon entry rates into houses placed on fractured soil. The main conclusion is, that fractures does not in general alter transport of internally generated radon out of soil, when the pressure and flow conditions in the soil is comparable to the conditions prevailing under a house. This indicates the important result, that fractures in soil have no impact on radon entry into a house beyond that of an increased gas permeability, but a more thorough investigation of this subject is needed. Only in the case where the soil is exposed to large pressure gradients, relative to gradients induced by a house, may it be possible to observe effects of radon exchange between fractures and matrix. (au) 52 tabs., 60 ill., 5 refs

  4. Radon transport in fractured soil. Laboratory experiments and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, A

    1997-10-01

    Radon (Rn-222) transport in fractured soil has been investigated by laboratory experiments and by modelling. Radon transport experiments have been performed with two sand columns (homogeneous and inhomogeneous) and one undisturbed clayey till column containing a net of preferential flow paths (root holes). A numerical model (the finite-element model FRACTRAN) and an analytic model (a pinhole model) have been applied in simulations if soil gas and radon transport in fractured soil. Experiments and model calculations are included in a discussion of radon entry rates into houses placed on fractured soil. The main conclusion is, that fractures does not in general alter transport of internally generated radon out of soil, when the pressure and flow conditions in the soil is comparable to the conditions prevailing under a house. This indicates the important result, that fractures in soil have no impact on radon entry into a house beyond that of an increased gas permeability, but a more thorough investigation of this subject is needed. Only in the case where the soil is exposed to large pressure gradients, relative to gradients induced by a house, may it be possible to observe effects of radon exchange between fractures and matrix. (au) 52 tabs., 60 ill., 5 refs.

  5. Contribution of radon in natural gas to the dose from aiborne radon-daughters in homes

    International Nuclear Information System (INIS)

    Barton, C.J.; Moore, R.E.; Rohwer, P.S.

    1973-01-01

    Data have been obtained on the radon concentration in natural gas supplied to several metropolitan areas in the United States. The average value of 20 pCi/l was selected to estimate the contribution of this source of natural radioactivity to doses from radon-daughters received by individuals in homes. Radon-daughter concentrations in the home atmosphere were calculated by use of computer programs for an 8000 ft 3 house in which 27 ft 3 of gas per day was used for cooking in an unvented kitchen range. The total estimated dose to the bronchial epithelium included contributions from radon plus daughters in the outside ventilation air, each of which was assumed to be present at a concentration of 0.13 pCi/l, and from the radon plus daughters in the natural gas. The latter contribution averaged approximately 3 percent of the total dose. There was a 3.5 percent decrease in the estimated total dose when the air change rate increased from 0.25 to 2.0 per hour. We conclude that radon and radon-daughters entering the home with natural gas produce a negligible fraction of the total dose to the respiratory system of home occupants from airborne radon-daughters

  6. A modeling study of the effect of depth of burial of depleted uranium and thorium on radon gas flux at a dry desert alluvial soil radioactive waste management site (RWMS)

    International Nuclear Information System (INIS)

    Lindstrom, F.T.; Cawlfield, D.E.; Emer, D.F.; Shott, G.J.

    1993-08-01

    An integral part of designing low-level waste (LLW) disposal pits and their associated closure covers in very dry desert alluvium is the use of a radon gas transport and fate model. Radon-222 has the potential to be a real heath hazard. The production of radon-222 results from the radioactive decay (a particle emission) of radium-226 in the uranium-235 and 238 Bateman chains. It is also produced in the thorium-230 series. Both long lived radionuclides have been proposed for disposal in the shallow land burial pits in Area 5 RWMS compound of Nevada Test Site (NTS). The constructed physics based model includes diffusion and barometric pressure-induced advection of an M-chain of radionuclides. The usual Bateman decay mechanics are included for each radionuclide. Both linear reversible and linear irreversible first order sorption kinetics are assumed for each radionuclide. This report presents the details of using the noble gas transport model, CASCADR9, in an engineering design study mode. Given data on the low-level waste stream, which constitutes the ultimate source of radon-222 in the RWMS, CASCADR9 is used to generate the surface flux (pCi/cm 2 -sec) of radon-222 under the realistic atmospheric and alluvial soil conditions found in the RWMS at Area 5, of the NTS. Specifically, this study examines the surface flux of radon-222 as a function of the depth of burial below the land surface

  7. Radon measurements over a natural-gas contaminated aquifer

    International Nuclear Information System (INIS)

    Palacios, D.; Fusella, E.; Avila, Y.; Salas, J.; Teixeira, D.; Fernández, G.; Salas, A.; Sajo-Bohus, L.; Greaves, E.; Barros, H.; Bolívar, M.; Regalado, J.

    2013-01-01

    Radon and thoron concentrations in soil pores in a gas production region of the Anzoategui State, Venezuela, were determined by active and passive methods. In this region, water wells are contaminated by natural gas and gas leaks exist in the nearby river. Based on soil gas Radon data surface hydrocarbon seeps were identified. Radon and thoron concentration maps show anomalously high values near the river gas leaks decreasing in the direction of water wells where natural gas is also detected. The area where the highest concentrations of 222 Rn were detected seems to indicate the surface projection of the aquifer contaminated with natural gas. The Radon/Thoron ratio revealed a micro-localized anomaly, indicating the area where the gas comes from deep layers of the subsoil. The radon map determined by the passive method showed a marked positive anomaly around abandoned gas wells. The high anomalous Radon concentration localized near the trails of ascending gas bubbles at the river indicates the zone trough where natural gases are ascending with greater ease, associated with a deep geological fault, being this the main source of methane penetration into the aquifer. It is suggested that the source of the natural gas may be due to leaks at deep sites along the structure of some of the abandoned wells located at the North-East of the studied area. - Highlights: ► High Radon/Thoron ratios were localized near the natural-gas emanations in a river. ► Natural gases are ascending trough a deep geological fault. ► Apparently, the radon anomaly shows the site where natural gas enters the aquifer. ► Natural gas source may be related to leaks in the structure of abandoned gas wells

  8. Measurement of radon exhalation rate and soil gas radon concentration in areas of southern Punjab (Pakistan)

    International Nuclear Information System (INIS)

    Mujahid, S. A.; Hussain, S.; Ramzan, M.

    2010-01-01

    Plastic track detectors were used to measure the radon concentration and exhalation rate from the soil samples. The samples were collected from areas of southern Punjab (Pakistan). In a laboratory experiment, passive alpha dosemeters were installed inside cylindrical bottles containing the soil samples. The radon concentrations and the radon exhalation rate were found in the ranges of 34±7 to 260±42 Bq m -3 and 38±8 to 288±46 mBq m -2 h -1 , respectively. The on-site measurements of radon in the soil gas were also carried out in these areas using a scintillation alpha counter. The concentration of radon in the soil gas was found in the range of 423±82-3565±438 Bq m -3 . (authors)

  9. Radon depletion in xenon boil-off gas

    Energy Technology Data Exchange (ETDEWEB)

    Bruenner, S.; Cichon, D.; Lindemann, S.; Undagoitia, T.M.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2017-03-15

    An important background in detectors using liquid xenon for rare event searches arises from the decays of radon and its daughters. We report for the first time a reduction of {sup 222}Rn in the gas phase above a liquid xenon reservoir. We show a reduction factor of >or similar 4 for the {sup 222}Rn concentration in boil-off xenon gas compared to the radon enriched liquid phase. A semiconductor-based α-detector and miniaturized proportional counters are used to detect the radon. As the radon depletion in the boil-off gas is understood as a single-stage distillation process, this result establishes the suitability of cryogenic distillation to separate radon from xenon down to the 10{sup -15} mol/mol level. (orig.)

  10. Radon gas monitoring survey for the determination of Radon Prone Areas in Lombardia

    Energy Technology Data Exchange (ETDEWEB)

    Bartolo, D. de; Alberici, A.; Gallini, R.; Maggioni, T.; Mondini, A.; Zini, E. [A.R.P.A. della Lombardia, Milano (Italy); Arrigoni, S.; Cazzaniga, P.; Cugini, A.; Gallinari, G.; Olivieri, F.; Romanelli, M. [A.R.P.A. della Lombardia, Dipt. di Bergamo, Bergamo (Italy)

    2006-07-01

    Region Lombardia has carried out a radon gas monitoring survey on its territory to localize radon prone areas as by law 241/00 enacted. To plan the survey, the Lombardia territory has been divided into two different types according to the morphology as well as the presence of a substratum of rock. The area with hills and mountains has been investigated with more attention compared to the plain because we can assume higher variability in radon concentration distribution due to the geological and morphological characteristics. The territory subdivision was based on the standard grid.. of the techniregional cartography (8 x 5 km). To perform radon indoor concentration measurements about 3600 measuring points were selected. They are located at the ground floor of buildings with the characteristics to ensure the tests are representative and comparable. It has also been taken into account evaluations done with previous surveys in accordance with the defined specification of the sites. The measurements were carried out using C.R. 39 trace detector technique. The detectors were contained in closed plastic canisters and they were positioned in situ for one year and measured each semester. The detectors were chemically treated and the traces counted using the automated optical system installed at the Radiometric Laboratory of the A.R.P.A. Department in Bergamo. The instrument accuracy and precision were evaluated using data obtained with different methods: using detectors exposed to radon known concentrations, participating to an international intercomparison as well as exposing the detector in a national calibration centre. Due to the large amount of detectors involved, a particular attention was taken for the detector homogeneity response and for the optimization of the analysis parameters. For further investigating the reliability of the measurements, two detectors were used in parallel in 10% of the tests. The results show higher values in the areas of Bergamo, Brescia

  11. Property transfer assessments should include radon gas testing

    International Nuclear Information System (INIS)

    Nardi, M.A.

    1992-01-01

    There are two emerging influences that will require radon gas testing as part of many property transfers and most environmental assessments. These requirements come from lending regulators and state legislatures and affect single family, multifamily, and commercial properties. Fannie Mae and others have developed environmental investigation guidelines for protection from long term legal liabilities in the purchase of environmentally contaminated real estate. These guidelines include radon gas testing for many properties. Several states have enacted laws that require environmental disclosure forms be prepared to ensure that the parties involved in certain real estate transactions are aware of the environmental liabilities that may come with the transfer of property. Indiana has recently enacted legislation that would require the disclosure of the presence of radon gas on many commercial real estate transactions. With more banks and state governments following this trend, radon gas testing should be performed during all property transfers and environmental assessments to protect the parties involved from any long term legal liabilities

  12. Environmental site assessments should include radon gas testing

    International Nuclear Information System (INIS)

    Nardi, M.A.

    1991-01-01

    There are two emerging influences that will require radon gas testing as part of many property transfers and most site assessments. These requirements come from lending regulators and state legislatures. Fannie Mae and others have developed environmental investigation guidelines for the purchase of environmentally contaminated real estate. These guidelines include radon gas testing for many properties. Several states have enacted laws that require environmental disclosure forms be prepared to ensure that the parties involved in certain real estate transactions are aware of the environmental liabilities that may come with the transfer of property. Indiana has recently enacted legislation that would require the disclosure of the presence of radon gas on many commercial real estate transactions. With more lenders and state governments likely to follow this trend, radon gas testing should be performed during all property transfers and site assessment to protect the parties involved from any legal liabilities

  13. Radon gas exposure levels in some selected areas in Egypt

    International Nuclear Information System (INIS)

    Ali, E.M.; Taha, T.M.; Gomaa, M.A.; El-Hussein, A.M.; Ahmed, A.A.

    2005-01-01

    During a summer season of 2003, the atmospheric concentrations of radon gas were measured indoor every one-hour for twenty-four hour measurements in some selected areas, using Pylon-AB4. Two hundreds and forty samples were monitored to determine the concentration of radon gas at each location using high-efficiency Lucas type continuous passive cell. The average values of radon gas concentration were taken in three time intervals 6.00:18.00, 18.00:6.00 and whole day. The average values of indoor radon gas of two locations using three time intervals were 4.82±0.63, 9±0.71 and 6.9±0.33 and 9.6±0.23, 11.82±0.42 and 9.37±0.7 Bq/m /h. respectively. The exposure levels were within the ICRP and EPA recommendations

  14. Does natural gas increase the indoor radon levels?

    International Nuclear Information System (INIS)

    Abdel-Ghany, H.A.; Shabaan, D.H.

    2015-01-01

    The natural gas is naturally occurring hydrocarbon consists mainly of methane and includes varying amounts of other hydrocarbons, carbon dioxide and other impurities such as: nitrogen, and hydrogen sulfide. It is used domestically and industrially as a preferable energy source compared to coal and oil. Because natural gas is found in deep underground natural formations or associated with other underground hydrocarbon reservoirs, there is a potential to contain radon as a contaminant. This work was designated to measure indoor radon concentrations in dwellings supplied with natural gas compared with those not supplied with it, where radon level was estimated using solid state nuclear track detectors (CR-39). The results showed that radon concentration was significantly higher in dwellings supplied with natural gas, where it was 252.30 versus 136.19 Bqm -3 in dwelling not supplied with natural gas (P < 0.001). The mean values of radon exhalation rate was 0.02 ± 6.34 · 10 -4 Bq · m -2 · h -1 in dwellings supplied with natural gas and 0.01 +- 0.008 Bq · m -2 · h -1 in dwellings lacking it. In addition, a significant difference was observed in the mean annual effective doses (4.33 and 2.34 mSv · y -1 , respectively) between both groups. Conclusively, the data indicate that natural gas may represent a potential source of indoor radon

  15. Environmental Radon Gas and Degenerative Conditions An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Groves-Kirkby, C.J. [Medical Physics Department, Northampton General Hospital, Northampton NN1 5BD (United Kingdom)]|[School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom); Denman, A.R. [Medical Physics Department, Northampton General Hospital, Northampton NN1 5BD (United Kingdom); Woolridge, A.C. [School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom)]|[School of Applied Sciences, University of Northampton, Northampton NN2 7AL (United Kingdom); Phillips, P.S. [School of Applied Sciences, University of Northampton, Northampton NN2 7AL (United Kingdom); Phillips, C. [School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom)

    2006-07-01

    Radon, a naturally occurring radioactive gas, has variable distribution in the environment as a decay product of uranium occurring in a wide range of rocks, soils and building materials. Although radon dissipates rapidly in outdoor air, it concentrates in the built environment, and inhalation of {sup 222}Rn and its progeny {sup 218}Po and {sup 214}Po is believed to provide the majority of the radioactive dose to the respiratory system. While the connection between radon and lung cancer has long been recognised and investigated, recent studies have highlighted potential links between radon and other conditions, among them Multiple Sclerosis, Alzheimer and Parkinson Diseases, and Paget Disease of Bone. A strong case exists for clarifying the relationship between radon and these other conditions, not least since radon remediation to reduce lung cancer may conceivably have additional benefits hitherto unrecognized. The present status of the postulated links between environmental radon gas and degenerative conditions is reviewed, and recommendations for further research into levering current anti-radon campaigns are made. (authors)

  16. Environmental Radon Gas and Degenerative Conditions An Overview

    International Nuclear Information System (INIS)

    Groves-Kirkby, C.J.; Denman, A.R.; Woolridge, A.C.; Phillips, P.S.; Phillips, C.

    2006-01-01

    Radon, a naturally occurring radioactive gas, has variable distribution in the environment as a decay product of uranium occurring in a wide range of rocks, soils and building materials. Although radon dissipates rapidly in outdoor air, it concentrates in the built environment, and inhalation of 222 Rn and its progeny 218 Po and 214 Po is believed to provide the majority of the radioactive dose to the respiratory system. While the connection between radon and lung cancer has long been recognised and investigated, recent studies have highlighted potential links between radon and other conditions, among them Multiple Sclerosis, Alzheimer and Parkinson Diseases, and Paget Disease of Bone. A strong case exists for clarifying the relationship between radon and these other conditions, not least since radon remediation to reduce lung cancer may conceivably have additional benefits hitherto unrecognized. The present status of the postulated links between environmental radon gas and degenerative conditions is reviewed, and recommendations for further research into levering current anti-radon campaigns are made. (authors)

  17. The perceived health risks of indoor radon gas and overhead powerlines: a comparative multilevel approach.

    Science.gov (United States)

    Poortinga, Wouter; Cox, Patrick; Pidgeon, Nick F

    2008-02-01

    Radon and overhead powerlines are two radiation risk cases that have raised varying levels of concern among the general public and experts. Despite both involving radiation-a typically feared and unseen health hazard-individuals' perceptions of the two risk cases may invoke rather different factors. We examined individual and geographic-contextual factors influencing public perceptions of the health risks of indoor radon gas and overhead powerlines in a comparative research design, utilizing a postal questionnaire with 1,528 members of the general public (response rate 28%) and multilevel modeling techniques. This study found that beliefs about the two risk cases mainly differed according to the level of "exposure"-defined here in terms of spatial proximity. We argue that there are two alternative explanations for this pattern of findings: that risk perception itself varies directly with proximity, or that risk is more salient to concerned people in the exposed areas. We also found that while people living in high radon areas are more concerned about the risks of indoor radon gas, they find these risks more acceptable and have more trust in authorities. These results might reflect the positive effects of successive radon campaigns in high radon areas, which may have raised awareness and concern, and at the same time may have helped to increase trust by showing that the government takes the health risks of indoor radon gas seriously, suggesting that genuine risk communication initiatives may have positive impacts on trust in risk management institutions.

  18. Soil radium, soil gas radon and indoor radon empirical relationships to assist in post-closure impact assessment related to near-surface radioactive waste disposal.

    Science.gov (United States)

    Appleton, J D; Cave, M R; Miles, J C H; Sumerling, T J

    2011-03-01

    Least squares (LS), Theil's (TS) and weighted total least squares (WTLS) regression analysis methods are used to develop empirical relationships between radium in the ground, radon in soil and radon in dwellings to assist in the post-closure assessment of indoor radon related to near-surface radioactive waste disposal at the Low Level Waste Repository in England. The data sets used are (i) estimated ²²⁶Ra in the < 2 mm fraction of topsoils (eRa226) derived from equivalent uranium (eU) from airborne gamma spectrometry data, (ii) eRa226 derived from measurements of uranium in soil geochemical samples, (iii) soil gas radon and (iv) indoor radon data. For models comparing indoor radon and (i) eRa226 derived from airborne eU data and (ii) soil gas radon data, some of the geological groupings have significant slopes. For these groupings there is reasonable agreement in slope and intercept between the three regression analysis methods (LS, TS and WTLS). Relationships between radon in dwellings and radium in the ground or radon in soil differ depending on the characteristics of the underlying geological units, with more permeable units having steeper slopes and higher indoor radon concentrations for a given radium or soil gas radon concentration in the ground. The regression models comparing indoor radon with soil gas radon have intercepts close to 5 Bq m⁻³ whilst the intercepts for those comparing indoor radon with eRa226 from airborne eU vary from about 20 Bq m⁻³ for a moderately permeable geological unit to about 40 Bq m⁻³ for highly permeable limestone, implying unrealistically high contributions to indoor radon from sources other than the ground. An intercept value of 5 Bq m⁻³ is assumed as an appropriate mean value for the UK for sources of indoor radon other than radon from the ground, based on examination of UK data. Comparison with published data used to derive an average indoor radon: soil ²²⁶Ra ratio shows that whereas the published data are

  19. Preliminary Study for 3D Radon Distribution Modelling in the Room

    Energy Technology Data Exchange (ETDEWEB)

    Lee, ChoongWie; Kim, HeeReyoung [UNIST, Ulsan (Korea, Republic of)

    2016-10-15

    Radon exists in the form of noble gas, which comes from decay of {sup 238}U, becoming stable {sup 206}Pb going through 4 alpha and 4 beta decays. If this process occurred in human body after inhalation, lung could be damaged by interaction with these radiations causing lung cancer. Most radon in indoor air comes from soil (85 - 97%) through crack of the wall but it also came from wall (2 - 5%) itself in home. Due to its hazardous and unpredictable characteristic, radon became one of the concerning nuclides in indoor air. Hence, the number of survey and research about radon has been increased. Although accurate radon measurement is important to evaluate health risk, it is hard to actually achieve because radon is affected by many conditions, where its concentration can vary easily. Moreover, radon concentration can vary according to the height because of density of radon in the spatial aspect. 3D distribution modelling in the room of radon with aerodynamic features and sources variations was carried out to find average and maximum radon concentration. 3D radon distribution in the room would be find through this computational analysis and it is thought to be possible to correct measured radon concentration with spatial variation to fit the height of nose where inhalation occur. The methodological concept for 3D modelling was set up to solve transport equation for radon behavior by using computational fluid dynamics (CFD) software such as FLUENT.

  20. Soil-gas radon as seismotectonic indicator in Garhwal Himalaya

    International Nuclear Information System (INIS)

    Ramola, R.C.; Prasad, Yogesh; Prasad, Ganesh; Kumar, Sushil; Choubey, V.M.

    2008-01-01

    Research on earthquake-related radon monitoring has received enormous attention recently. Anomalous behaviour of radon in soil and groundwater can be used as a reliable precursor for an impending earthquake. While earthquake prediction may not yet be possible, earthquake prediction research has greatly increased our understanding of earthquake source mechanisms, the structural complexities of fault zones, and the earthquake recurrence interval, expected at a given location. This paper presents some results of continuous monitoring of radon in soil-gas in Garhwal Himalaya, India. Daily soil-gas radon monitoring with seismic activity and meteorological parameters were performed in the same laboratory system, located at H.N.B. Garhwal University Campus, Tehri Garhwal, India. Radon anomalies along with meteorological parameters were found to be statistically significant for the seismic events within the magnitudes M2.0-M6.0 and epicentral distances of 16-250 km from the monitoring station. The frequent positive and negative anomalies with constant environmental perturbation indicate the opening and closing of micro cracks within the volume of dilatancy by strain energy. The spike-like and sharp peak anomalies were recorded before, during and after earthquakes occurred in the area. The variations in radon concentrations in soil-gas are found to be correlated with seismic activities in the Garhwal Himalaya. The correlation between radon level and meteorological parameters is also discussed

  1. Establishing the level of exposure to radon gas in dwellings

    International Nuclear Information System (INIS)

    Karupa, Jackson Uakaningirua

    2016-04-01

    The main source of natural internal irradiation of man is radon and its decay products. In this study, the radon concentration levels in selected dwellings in Erongo region, Swakopmund, Namibia will be estimated using passive or active radon detector. The primary objective of the study is to measure and establish radon levels in selected dwellings in Erongo region, Swakopmund of Namibia. Measurements will be carried out for the period of twelve months and after three months period the detectors will be exchanged for laboratory analysis. The results obtained from the study will reveal the concentration of radon in most of the selected dwellings in Erongo region, Swakopmund, Namibia. Once Radon level is measured or identified, the results with data from work done in other environments in Africa and elsewhere will be compared. In case of high radon concentrations in dwelling, the occupants will be advised to ensure good ventilation practices as cost effective means of mitigation of indoor radon gas level in the area. (au)

  2. Risk Assessment from Radon Gas in the Greenhouses

    International Nuclear Information System (INIS)

    Fahmi, N.M.; El-Khatib, A.M.; Abd El-Zaher, M

    2009-01-01

    Radon is a naturally occurring radioactive gas found in varying amounts in all soils. Therefore, it is very important to study radon emanation from different soils in different circumstances; especially, in green houses which widely used to propagate and cultivate of plants. In greenhouses radon comes from either soil or the substances which make suitable flooring in the greenhouse. Radon and its progeny are accumulated in the air and on the plants themselves, which causes hazard for workers and customers in a later stage. Radon gas is measured in two kinds of greenhouses, one of them is constructed from plastic sheet and the other from glass (Agriculture Research Center - Horticulture Research Institute) using CR-39 NTDs as a passive technique. It based on the production of track in the detector due to alpha-particles emitted from radon and its progeny. The observed track densities are then converted to annual radon dose to be 12.36 mSv and 8.3 mSv for the plastic and glass greenhouses under investigation, respectively. It is also found that the workers have been subject to regulatory control

  3. Modeled atmospheric radon concentrations from uranium mines

    Energy Technology Data Exchange (ETDEWEB)

    Droppo, J.G.

    1985-04-01

    Uranium mining and milling operations result in the release of radon from numerous sources of various types and strengths. The US Environmental Protection Agency (EPA) under the Clean Air Act, is assessing the health impact of air emissions of radon from underground uranium mines. In this case, the radon emissions may impact workers and residents in the mine vicinity. To aid in this assessment, the EPA needs to know how mine releases can affect the radon concentrations at populated locations. To obtain this type of information, Pacific Northwest Laboratory used the radon emissions, release characteristics and local meterological conditions for a number of mines to model incremental radon concentrations. Long-term, average, incremental radon concentrations were computed based on the best available information on release rates, plume rise parameters, number and locations of vents, and local dispersion climatology. Calculations are made for a model mine, individual mines, and multiple mines. Our approach was to start with a general case and then consider specific cases for comparison. A model underground uranium mine was used to provide definition of the order of magnitude of typical impacts. Then computations were made for specific mines using the best mine-specific information available for each mine. These case study results are expressed as predicted incremental radon concentration contours plotted on maps with local population data from a previous study. Finally, the effect of possible overlap of radon releases from nearby mines was studied by calculating cumulative radon concentrations for multiple mines in a region with many mines. The dispersion model, modeling assumptions, data sources, computational procedures, and results are documented in this report. 7 refs., 27 figs., 18 tabs.

  4. Modeled atmospheric radon concentrations from uranium mines

    International Nuclear Information System (INIS)

    Droppo, J.G.

    1985-04-01

    Uranium mining and milling operations result in the release of radon from numerous sources of various types and strengths. The US Environmental Protection Agency (EPA) under the Clean Air Act, is assessing the health impact of air emissions of radon from underground uranium mines. In this case, the radon emissions may impact workers and residents in the mine vicinity. To aid in this assessment, the EPA needs to know how mine releases can affect the radon concentrations at populated locations. To obtain this type of information, Pacific Northwest Laboratory used the radon emissions, release characteristics and local meterological conditions for a number of mines to model incremental radon concentrations. Long-term, average, incremental radon concentrations were computed based on the best available information on release rates, plume rise parameters, number and locations of vents, and local dispersion climatology. Calculations are made for a model mine, individual mines, and multiple mines. Our approach was to start with a general case and then consider specific cases for comparison. A model underground uranium mine was used to provide definition of the order of magnitude of typical impacts. Then computations were made for specific mines using the best mine-specific information available for each mine. These case study results are expressed as predicted incremental radon concentration contours plotted on maps with local population data from a previous study. Finally, the effect of possible overlap of radon releases from nearby mines was studied by calculating cumulative radon concentrations for multiple mines in a region with many mines. The dispersion model, modeling assumptions, data sources, computational procedures, and results are documented in this report. 7 refs., 27 figs., 18 tabs

  5. Radon levels in dwellings in chalk terrain. Development and analysis of distributional and causal models

    International Nuclear Information System (INIS)

    Killip, Ian Richmond

    2002-01-01

    This thesis investigates the range, distribution and causes of high radon levels in dwellings in the Brighton area of Southeast England. Indoor radon levels were measured in more than 1000 homes. The results show that high radon levels can arise in an area previously considered to offer low radon potential from local geological sources. Climate and building-related factors were found to affect significantly the radon levels in dwellings. Multiple regression was used to determine the influence of the various factors on indoor radon levels and an empirical model develop to predict indoor radon levels. The radon hazard, independent of building-related effects, was determined for each surveyed location by adjusting the radon measurement to that expected on the ground floor of a 'model' dwelling. This standardised set of radon levels was entered into a geographical information system (GIS) and related to surface geology. The geometric mean radon level for each lithological unit was plotted to produce a radon hazard map for the area. The highest radon levels were found to be associated with the youngest Chalk Formations, particularly where they meet overlying Tertiary deposits, and with Clay-with-Flints Quaternary deposits in the area. The results were also converted to the radon activity equivalent to that expected from the NRPB's standard dual-detector dwelling survey method and analysed by lognormal modelling to estimate the proportion of dwellings likely to exceed the UK Action Level of 200 Bq/m 3 for each lithological unit. The likely percentages of dwellings affected by radon thus obtained were mapped to lithological boundaries to produce a radon potential map. The radon hazard map and the empirical radon model facilitate the prediction of radon levels in dwellings of comparable construction and above similar geology and should further the understanding of the behaviour of radon gas in buildings to allow indoor radon concentrations to be controlled. The radon

  6. The 2008 intercomparison exercise for radon gas measurement instruments at PSI; Die Vergleichsmessung 2008 fuer Radongasmessgeraete am PSI

    Energy Technology Data Exchange (ETDEWEB)

    Butterweck, G.; Schuler, Ch.; Mayer, S.

    2010-09-15

    Sixteen radon measurement services participated in the 2008 Radon Intercomparison Exercise performed at the Reference Laboratory for Radon Gas Activity Concentration Measurements at the Paul Scherrer Institute (PSI) during August 28{sup th} to September 7{sup th}, 2008 on behalf of the Swiss Federal Office of Public Health (FOPH). Twelve of these laboratories were approved by the FOPH and their participation in the intercomparison exercise was a requirement to warrant quality of measurement. Radon gas dosemeters (etched-track, electronic and electret ionisation chambers) and instruments (ionization chambers) were exposed in the PSI Radon Chamber in a reference atmosphere with an average radon gas concentration of 627 Bq m{sup -3} leading to a radon gas exposure of 155 kBq h m{sup -3}. One measuring instrument participating for testing purposes stored values for part of the exposure interval (30.8. - 7.9.2008). The exposure during this partial interval was 117 kBq h m{sup -3} at an average radon gas concentration of 624 Bq m{sup -3}. The exposure of 155 kBq h m{sup -3} was the lowest used at the PSI intercomparisons down to the present day. Especially the LLT electret ionisation chambers used by some of the laboratories reached the lower end of their measurement range with this exposure. Unexpected deviations of instruments of the same model seem to show a dependence on the serial number and thus production date. (authors)

  7. Can radon gas measurements be used to predict earthquakes?

    International Nuclear Information System (INIS)

    2009-01-01

    After the tragic earthquake of April 6, 2009 in Aquila (Abruzzo), a debate has begun in Italy regarding the alleged prediction of this earthquake by a scientist working in the Gran Sasso National Laboratory, based on radon content measurements. Radon is a radioactive gas originating from the decay of natural radioactive elements present in the soil. IRSN specialists are actively involved in ongoing research projects on the impact of mechanical stresses on radon emissions from underground structures, and some of their results dating from several years ago are being brought up in this debate. These specialists are therefore currently presenting their perspective on the relationships between radon emissions and seismic activity, based on publications on the subject. (authors)

  8. The Innovative Design of Lucas Cell for Radon Gas Measurement

    International Nuclear Information System (INIS)

    Wanabongse, Paitoon; Rattanabussayaporn, Sakon; Sriya, Maitree; Sola, Banthom

    2007-08-01

    Full text: Lucas scintillation cell has been widely used for radon gas measurement. They are commercially available but usually with a rather high price, therefore, four cells were developed and built in house. The invented radon gas detector has a special feature; the circumference of the upper part of the cylindrical detector is larger than the lower part. The purpose of this is to allow the light sensing device coupled at the lower end can better detect the phosphorescence light occurred inside. The result is that the invented detector yields higher detection efficiency. This special feature also allows us to increase the volume of the detector which results in higher detection sensitivity

  9. The 2010 calibration campaign for radon gas measuring instruments at PSI

    International Nuclear Information System (INIS)

    Butterweck, G.; Schuler, Ch.; Mayer, S.

    2011-01-01

    Twenty radon measurement services or the respective analytical laboratories participated in the 2010 Radon Intercomparison Exercise performed at the Reference Laboratory for Radon Gas Activity Concentration Measurements at the Paul Scherrer Institute (PSI) from August 27 th to August 31 st , 2010 on behalf of the Swiss Federal Office of Public Health (FOPH). Twelve of these laboratories were approved by the FOPH and their participation in the intercomparison exercise was a requirement to warrant quality of measurement. Radon gas dosemeters (track-etch, electronic and electret) and instruments (ionisation chambers) were exposed in the PSI Radon Chamber in a reference atmosphere with an average radon gas concentration of 595 Bq m -3 leading to a radon gas exposure of 57 kBq h m -3 . The exposure of 57 kBq h m -3 was close to the lower value of the measuring range defined in the Radon Measurement Ordinance ('Radon-Messmittelverordnung'). (authors)

  10. The use of radon gas techniques for earthquake prediction

    International Nuclear Information System (INIS)

    Al-Hilal, M.

    1993-01-01

    This scientific article explains the applications of radon gas measurements in water and soil for monitoring fault activities and earthquake prediction. It also emphasizes, through some worldwide examples presented from Tashkent Basin in U.S.S.R. and from San Andreas fault in U.S.A, that the use of radon gas technique in fault originated water as well as in soil gases can be considered as an important geological-tool, within the general framework of earthquake prediction because of the coherent and time anomalous relationship between the density of alpha particles due to radon decay and between the tectonic activity level along fault zones. The article also indicates, and through the practical experience of the author, to the possibility of applying such techniques in certain parts of Syria. (author). 6 refs., 4 figs

  11. Radon

    Science.gov (United States)

    ... radon-resistant features. These features include gravel and plastic sheeting below the foundation, along with proper sealing ... lower the radon level. Detailed information about radon reduction in your home or building can be found ...

  12. State-space dynamic model for estimation of radon entry rate, based on Kalman filtering

    International Nuclear Information System (INIS)

    Brabec, Marek; Jilek, Karel

    2007-01-01

    To predict the radon concentration in a house environment and to understand the role of all factors affecting its behavior, it is necessary to recognize time variation in both air exchange rate and radon entry rate into a house. This paper describes a new approach to the separation of their effects, which effectively allows continuous estimation of both radon entry rate and air exchange rate from simultaneous tracer gas (carbon monoxide) and radon gas measurement data. It is based on a state-space statistical model which permits quick and efficient calculations. Underlying computations are based on (extended) Kalman filtering, whose practical software implementation is easy. Key property is the model's flexibility, so that it can be easily adjusted to handle various artificial regimens of both radon gas and CO gas level manipulation. After introducing the statistical model formally, its performance will be demonstrated on real data from measurements conducted in our experimental, naturally ventilated and unoccupied room. To verify our method, radon entry rate calculated via proposed statistical model was compared with its known reference value. The results from several days of measurement indicated fairly good agreement (up to 5% between reference value radon entry rate and its value calculated continuously via proposed method, in average). Measured radon concentration moved around the level approximately 600 Bq m -3 , whereas the range of air exchange rate was 0.3-0.8 (h -1 )

  13. Radon anomaly in soil gas as an earthquake precursor

    International Nuclear Information System (INIS)

    Miklavcic, I.; Radolic, V.; Vukovic, B.; Poje, M.; Varga, M.; Stanic, D.; Planinic, J.

    2008-01-01

    The mechanical processes of earthquake preparation are always accompanied by deformations; afterwards, the complex short- or long-term precursory phenomena can appear. Anomalies of radon concentrations in soil gas are registered a few weeks or months before many earthquakes. Radon concentrations in soil gas were continuously measured by the LR-115 nuclear track detectors at site A (Osijek) during a 4-year period, as well as by the Barasol semiconductor detector at site B (Kasina) during 2 years. We investigated the influence of the meteorological parameters on the temporal radon variations, and we determined the equation of the multiple regression that enabled the reduction (deconvolution) of the radon variation caused by the barometric pressure, rainfall and temperature. The pre-earthquake radon anomalies at site A indicated 46% of the seismic events, on criterion M≥3, R<200 km, and 21% at site B. Empirical equations between earthquake magnitude, epicenter distance and precursor time enabled estimation or prediction of an earthquake that will rise at the epicenter distance R from the monitoring site in expecting precursor time T

  14. Radon anomaly in soil gas as an earthquake precursor

    Energy Technology Data Exchange (ETDEWEB)

    Miklavcic, I.; Radolic, V.; Vukovic, B.; Poje, M.; Varga, M.; Stanic, D. [Department of Physics, University of Osijek, Trg Ljudevita Gaja 6, POB 125, 31000 Osijek (Croatia); Planinic, J. [Department of Physics, University of Osijek, Trg Ljudevita Gaja 6, POB 125, 31000 Osijek (Croatia)], E-mail: planinic@ffos.hr

    2008-10-15

    The mechanical processes of earthquake preparation are always accompanied by deformations; afterwards, the complex short- or long-term precursory phenomena can appear. Anomalies of radon concentrations in soil gas are registered a few weeks or months before many earthquakes. Radon concentrations in soil gas were continuously measured by the LR-115 nuclear track detectors at site A (Osijek) during a 4-year period, as well as by the Barasol semiconductor detector at site B (Kasina) during 2 years. We investigated the influence of the meteorological parameters on the temporal radon variations, and we determined the equation of the multiple regression that enabled the reduction (deconvolution) of the radon variation caused by the barometric pressure, rainfall and temperature. The pre-earthquake radon anomalies at site A indicated 46% of the seismic events, on criterion M{>=}3, R<200 km, and 21% at site B. Empirical equations between earthquake magnitude, epicenter distance and precursor time enabled estimation or prediction of an earthquake that will rise at the epicenter distance R from the monitoring site in expecting precursor time T.

  15. Radon in soil gas survey in Curitiba (Brazil)

    International Nuclear Information System (INIS)

    Paschuk, Sergei A.; Correa, Janine Nicolosi; Schelin, Hugo R.; Barbosa, Laercio; Sadula, Tatyana; Matsuzaki, Cristiana A.

    2009-01-01

    This work describes the radon in soil gas measurements performed during the last two years in cooperation between the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR), the Nuclear Technology Development Center (CDTN) and the Institute of Radiation Protection and Dosimetry (IRD) from the Brazilian Nuclear Energy Commission (CNEN). Following previously concluded measurements of radon concentration in dwellings and the measurements of 222 Rn activity in drinking water collected at artesian bores of Curitiba urban area, present step of activities has been dedicated to measurements of radon concentration in soil gas. Experimental setup was based on the Professional Radon Monitor (ALPHA GUARD) connected to specially developed for such measurements Soil Gas Probe through the air pump and filter system. After the Probe was inserted, the ground has been tamped down around the probe, to prevent air from moving vertically along the outside of the shaft. The equipment was adjusted with air flow of 0.03 L/min and the measurements were performed during 90 min approximately. The 222 Rn concentration levels were detected and analyzed by the computer every 5 minutes using the software DataEXPERT by GENITRON Instruments. Collected average levels of 222 Rn concentration were processed taking into account the internal volume of Soil Probe and connection vessels. Radon sampling was performed at a depth of 50 - 70 cm. Obtained experimental data of radon concentration present rather big variation but correlates perfectly with previously obtained results for 222 Rn activity in drinking water. Further measurements are planned to be performed at other regions of Parana State and will involve the mineral analysis of soil samples. (author)''

  16. Radon diffusion through multilayer earthen covers: models and simulations

    International Nuclear Information System (INIS)

    Mayer, D.W.; Oster, C.A.; Nelson, R.W.; Gee, G.W.

    1981-09-01

    A capability to model and analyze the fundamental interactions that influence the diffusion of radon gas through uranium mill tailings and cover systems has been investigated. The purpose of this study is to develop the theoretical basis for modeling radon diffusion and to develop an understanding of the fundamental interactions that influence radon diffusion. This study develops the theoretical basis for modeling radon diffusion in one, two and three dimensions. The theory has been incorporated into three computer models that are used to analyze several tailings and cover configurations. This report contains a discussion of the theoretical basis for modeling radon diffusion, a discussion of the computer models used to analyze uranium mill tailings and multilayered cover systems, and presents the results that have been obtained. The study has been conducted using a four-phase approach. The first phase develops the solution to the steady-state radon-diffusion equation in one-dimensieered barriers; disposal charge analysis; analysis of spent fuel policy implementation; spent f water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Uranium concentrations in the sediments which were above detection limits ranged from 0.10 t 51.2 ppM. The mean of the logarithms of the uranium concentrations was 0.53. A group of high uranium concentrations occurs near the junctions of quadrangles AB, AC, BB, a 200 mK. In case 2), x-ray studies of isotopic phase separation in 3 He-- 4 He bcc solids were carried out by B. A. Fraass

  17. Use of the radon gas as a natural geophysical tracer

    International Nuclear Information System (INIS)

    Pena, P.; Balcazar, M.; Flores R, J.H.; Lopez M, A.

    2006-01-01

    In this work it is denoted the applications of the radon gas like a natural geophysical radiotracer in the different branches of the Earth Sciences (Geology, geophysics and geochemistry). It importance resides in its employment like one additional tool to register the possible occurrence of seismic events by means of radon anomalies that are presented in land movements (volcanic eruptions and presence of geothermal areas), as well as its potential in environmental works whose purpose is the evaluation of the feather of contamination in the underground water and the porous media for spills of hydrocarbons. The measurement techniques to determine the concentration of radon was carried out by means of Solid Detectors of Nuclear tracks, as well as by Liquid scintillation, Clipperton, Honeywell, AlphaGUARD. The towns where these techniques its were applied were: Mexico City, Estado de Mexico (Toluca, ININ), Jalisco (The Spring), Guerrero coast. (Author)

  18. Measurement of average radon gas concentration at workplaces

    International Nuclear Information System (INIS)

    Kavasi, N.; Somlai, J.; Kovacs, T.; Gorjanacz, Z.; Nemeth, Cs.; Szabo, T.; Varhegyi, A.; Hakl, J.

    2003-01-01

    In this paper results of measurement of average radon gas concentration at workplaces (the schools and kindergartens and the ventilated workplaces) are presented. t can be stated that the one month long measurements means very high variation (as it is obvious in the cases of the hospital cave and the uranium tailing pond). Consequently, in workplaces where the expectable changes of radon concentration considerable with the seasons should be measure for 12 months long. If it is not possible, the chosen six months period should contain summer and winter months as well. The average radon concentration during working hours can be differ considerable from the average of the whole time in the cases of frequent opening the doors and windows or using artificial ventilation. (authors)

  19. Natural environmental radioactivity and radon gas

    International Nuclear Information System (INIS)

    Lowder, W.M.

    1990-01-01

    In recent decades, much has been learned about the nature and sources of human exposure to naturally-occurring radiation and radionuclides. A brief historical perspective is given on this growth of knowledge, and recent assessments of the contributions of the various sources to human population radiation exposure are discussed. This provides the context for a consideration of the significance of exposure to airborne radon decay products for the global population and of future exposure of an increasing number of space travelers to cosmic radiation. (author). 13 refs, 4 tabs

  20. Use of the radon gas as a natural geophysical tracer; Utilizacion del gas radon como un trazador geofisico natural

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Balcazar, M.; Flores R, J.H.; Lopez M, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2006-07-01

    In this work it is denoted the applications of the radon gas like a natural geophysical radiotracer in the different branches of the Earth Sciences (Geology, geophysics and geochemistry). It importance resides in its employment like one additional tool to register the possible occurrence of seismic events by means of radon anomalies that are presented in land movements (volcanic eruptions and presence of geothermal areas), as well as its potential in environmental works whose purpose is the evaluation of the feather of contamination in the underground water and the porous media for spills of hydrocarbons. The measurement techniques to determine the concentration of radon was carried out by means of Solid Detectors of Nuclear tracks, as well as by Liquid scintillation, Clipperton, Honeywell, AlphaGUARD. The towns where these techniques its were applied were: Mexico City, Estado de Mexico (Toluca, ININ), Jalisco (The Spring), Guerrero coast. (Author)

  1. Radon reduction in waterworks

    International Nuclear Information System (INIS)

    Raff, O.; Haberer, K.; Wilken, R.D.; Funk, H.; Stueber, J.; Wanitschek, J.; Akkermann-Kubillus, A.; Stauder, S.

    2000-01-01

    The removal of radon from water using water aeration is one of the most effective methods for reducing radon in waterworks. Therefore, this report describes investigations on packed tower columns and shallow aeration devices and a method for mathematical modelling of gas exchange processes for dimensioning packed tower columns for radon removal. Moreover, possibilities for removing radon using active carbon filtration under waterworks typical conditions and for reducing indoor radon levels in waterworks are discussed. Finally, conclusions on the necessity of radon removal in German waterworks are drawn. (orig.) [de

  2. Mapping of gas radon in soil of the Fresnillo City, Zacatecas; Mapeo de gas radon en suelo de la Ciudad de Fresnillo, Zacatecas

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Q, I. S.; Lopez del R, H.; Davila R, J. I.; Mireles G, F., E-mail: hlopezdelrio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2012-10-15

    With the purpose of locating areas with high rates of gas radon exhalation, it has begun to measure the radon flow in soil for residence use in the Fresnillo City, Zacatecas State, Mexico, applying the method of the open vial and liquid scintillation. The gas radon accumulation is made in a camera situated to a depth between 25 and 35 cm. In this work the partial results of the research in course are presented. The values obtained for the radon exhalation have varied of <2.25 up to 14.42 Bq/m{sup 2}{center_dot}h. (Author)

  3. Radon as a tracer for soil-gas entry into a house located next to a contaminated dry-cleaning property; Radon som sporgas for jordluftindtraengning til hus ved forurenet renserigrund

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, C.E

    2001-07-01

    This study applies the naturally occurring radioactive gas radon-222 as a tracer for soil-gas entry into a house located next to a dry-cleaners shop. This is possible because the concentration of radon in the soil below the house is about 1000 times higher than the concentration in outdoor air. The study is based on continuous indoor measurement of radon, differential pressures, barometric pressure and temperatures and grab samples of radon below the slab and in the soil in the vicinity of the house. During the investigation, vacuum extraction were used to remove chlorinated solvents (perchloroethylene, PCE) from the unsaturated zone. The study shows that the vacuum extraction influences the radon concentration in and below the house. When the vacuum pump is on, the indoor radon concentration is only 10 Bq/m{sup 3} corresponding to the contribution from radon in outdoor air and exhalation from building materials. When the vacuum pump is set off, the average indoor radon concentration increases to 30 Bq/m{sup 3}. It is believed that the increase is caused by radon entry from the soil. Regression analysis demonstrates that changes in the indoor radon concentration can be explained by changes in indoor-outdoor pressure differences and changes in the atmospheric pressure. This suggests that advection is the primary mode of entry. Under some highly simplifying assumptions the soil-gas entry is found to be around 1 m{sup 3}/h. This, however, is most likely an overestimate. Based on the measured radon concentration in the exhaust air from the vacuum system and a typical radon emanation rate for Danish soil, it is estimated that the soil vapor extraction system ventilates about 10000 m{sup 3} of soil. The investigation is supported by numerical model calculations with the finite-volume model Rnmod3d. (au)

  4. Radon gas. A review with emphasis on site investigations and measurements of soil gas and indoor house levels

    International Nuclear Information System (INIS)

    Mitchell, Seamus.

    1992-09-01

    A review of radon gas, with particular reference to its source and transport through soils and into buildings is examined. The principal parameters affecting the movement of radon has been discussed. The levels of radon gas in soils and in dwelling houses has been examined. Radon levels in the soil gas were highest in mineral soils with pear soils giving low readings but there was no significant differences between the results. Houses situated over granite and limestone bedrock gave similar results for indoor radon concentrations, with no significant differences being recorded. Results were expected to be much higher in houses over granite areas, in view of the higher uranium series activity in granites. It is concluded that high radon gas levels in soils under and in he vicinity of houses is the probable explanation for the indoor radon levels found. The influence of the underlying bedrock is not the most important parameter as was surmised before the study. (author)

  5. Measurements of radon gas in dwellings of Argentina

    International Nuclear Information System (INIS)

    Canoba, A.C.; Arnaud, M.I.; Lopez, F.O.; Oliveira, A.A.

    1998-01-01

    The concentration of radon gas in dwellings of several cities of Argentina was measured. For this purpose, different kind of detectors were used such as passive solid state nuclear track detectors, electrets and detectors which use activated charcoal. Since 1983, a total of 1630 dwellings were analysed. The cases monitored were dwellings where the main construction materials are reinforced concrete and brick. The average values found in each city are below 50 Bq/m 3 . The values above 200-Bqm 3 are very few, and none of them is above 300 Bq/m 3 . The average value of radon gas in air dwellings in our country is 33 Bq/m 3 , with a geometric mean of 23 Bq/m 3 , corresponding to an annual effective dose of 0.83 mSv. (author) [es

  6. Radon

    International Nuclear Information System (INIS)

    1990-01-01

    This leaflet in the At-a-Glance Series, describes what radon is, where it is found, why it presents a risk to health, the official advice, and the remedies that are available to reduce radon levels. (author)

  7. Analysis of volatile phase transport in soils using natural radon gas as a tracer

    International Nuclear Information System (INIS)

    Chen, C.; Thomas, D.M.

    1992-01-01

    We have conducted a field study of soil gas transport processes using radon gas as a naturally occurring tracer. The experiment monitored soil gas radon activity, soil moisture, and soil temperature at three depths in the shallow soil column; barometric pressure, rainfall and wind speed were monitored at the soil surface. Linear and multiple regression analysis of the data sets has shown that the gas phase radon activities under natural environmental conditions are influenced by soil moisture content, barometric pressure variations, soil temperature and soil structure. The effect of wind speed on subsurface radon activities under our field conditions has not been demonstrated

  8. Modified design in new construction prevents infiltration of soil gas that carries radon

    International Nuclear Information System (INIS)

    Ericson, S.O.; Schmied, H.

    1987-01-01

    Dwellings located on permeable soil with strong exhalation of radon often get a contribution to indoor radon from infiltrating soil gas carrying radon from the ground into the building. 100 dwellings have been built on radon dangerous land with different modifications in design and construction in order to prevent infiltration of radon. Tight construction, ventilated crawl space, ventilation/depressurization of the capillary breaking layer (crushed stone), and mechanical ventilation with heat recovery by air to air heat exchangers or heat pumps have been tested. Added building costs and measured concentration of radon after construction and 3-5 years later are reported. It is concluded that it is possible to build radon protective and radon safe dwellings on any land. The added costs have ranged from zero to 4% of total building costs

  9. Radon gas measurements inside houses of the Argentine Republic

    International Nuclear Information System (INIS)

    Canoba, Analia C.; Arnaud, Marta I.; Lopez, Fabio O.; Oliveira, Antonio

    2001-01-01

    Indoor radon gas concentrations were measured in dwellings in various cities of Argentina. Solid-state nuclear track, electrets and activated charcoal detectors were the methods used for monitoring the radon concentration.A total of 2034 homes were monitored since the beginning of this project in 1983. The monitored homes are constructed of a variety of building materials but most of them are built predominantly of bricks and concrete. The mean values calculated for the different cities are below 50 Bq m -3 . Very few values above 200 Bq m -3 were found and none exceeded 300 Bq m -3 . The mean value for the whole country is 34.6 Bq m -3 with a geometric mean of 25.0 Bq m -3 and the corresponding annual effective dose is 0.86 mSv. (author)

  10. An electrical circuit model for simulation of indoor radon concentration.

    Science.gov (United States)

    Musavi Nasab, S M; Negarestani, A

    2013-01-01

    In this study, a new model based on electric circuit theory was introduced to simulate the behaviour of indoor radon concentration. In this model, a voltage source simulates radon generation in walls, conductivity simulates migration through walls and voltage across a capacitor simulates radon concentration in a room. This simulation considers migration of radon through walls by diffusion mechanism in one-dimensional geometry. Data reported in a typical Greek house were employed to examine the application of this technique of simulation to the behaviour of radon.

  11. An improved model for the reconstruction of past radon exposure.

    Science.gov (United States)

    Cauwels, P; Poffijn, A

    2000-05-01

    If the behavior of long-lived radon progeny was well understood, measurements of these could be used in epidemiological studies to estimate past radon exposure. Field measurements were done in a radon-prone area in the Ardennes (Belgium). The surface activity of several glass sheets was measured using detectors that were fixed on indoor glass surfaces. Simultaneously the indoor radon concentration was measured using diffusion chambers. By using Monte Carlo techniques, it could be proven that there is a discrepancy between this data set and the room model calculations, which are normally used to correlate surface activity and past radon exposure. To solve this, a modification of the model is proposed.

  12. Determination of radon concentration in soil gas by gamma-ray spectrometry of olive oil

    International Nuclear Information System (INIS)

    Al-Azmi, Darwish; Karunakara, N.

    2007-01-01

    Measurements of radon concentration in soil gas have been carried out using a bubbling system in which the soil gas is drawn through an active pumping to bubble a liquid absorber (olive oil) for the deposition of the soil gas in it. After the bubbling process, the absorber is then taken for gamma-ray measurements. Gamma-ray photopeaks from the 214 Pb and the 214 Bi radon progeny are considered for the detection of the 222 Rn gas to study the concentration levels for radon soil gas. Results for some field measurements were obtained and compared with results obtained using AlphaGuard radon gas monitor. The technique provides a possible approach for the measurements of radon soil gas with gamma-ray spectrometry

  13. Model dosimetric for Radon and Daughters

    International Nuclear Information System (INIS)

    Puerta, J.A.; Cardenas, H.F.

    1998-01-01

    You elaborates a model dosimetric for radon and their products of decline of short half life starting from the new model of the breathing tract of the publication 66 of the ICRP and the use of the systemic models proposed in the publication 67, 68 and 69 of the same commission. The correlated used methodology the incorporation of these radionuclides with the activity in organs and you excrete, considering the difference of metabolic behavior of the products of decline and of their predecessor

  14. Radon gas sampler for indoor and soil measurements and its applications

    International Nuclear Information System (INIS)

    Azimi-Garakani, D.; Flores, B.; Piermattei, S.; Susanna, A.F.; Seidel, J.L.; Tommasino, L.; Torri, G.

    1988-01-01

    A national large scale survey of indoor radon (based on an optimised sampling strategy) is needed in Italy to obtain average population dose for use in epidemiological studies. Since in the great majority of cases, one of the most important radon sources is the soil and rock beneath the houses, it would be interesting to combine this survey with measurements of bed-soil radon. With these objectives in mind, a new radon monitor device has been developed consisting of two etched track detectors enclosed in a heat-sealed polyethylene bag. When compared with existing techniques, this radon gas sampler presents several advantages for both indoor and outdoor measurements. As a pilot project, radon gas measurements have been carried out in hundreds of different sites and for several locations; measurements have been made for different years. Typical houses with relatively high radon concentrations have also been thoroughly investigated. (author)

  15. Residential radon in Finland: sources, variation, modelling and dose comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Arvela, H

    1995-09-01

    The study deals with sources of indoor radon in Finland, seasonal variations in radon concentration, the effect of house construction and ventilation and also with the radiation dose from indoor radon and terrestrial gamma radiation. The results are based on radon measurements in approximately 4000 dwellings and on air exchange measurements in 250 dwellings as well as on model calculations. The results confirm that convective soil air flow is by far the most important source of indoor radon in Finnish low-rise residential housing. (97 refs., 61 figs., 30 tabs.).

  16. Residential radon in Finland: sources, variation, modelling and dose comparisons

    International Nuclear Information System (INIS)

    Arvela, H.

    1995-09-01

    The study deals with sources of indoor radon in Finland, seasonal variations in radon concentration, the effect of house construction and ventilation and also with the radiation dose from indoor radon and terrestrial gamma radiation. The results are based on radon measurements in approximately 4000 dwellings and on air exchange measurements in 250 dwellings as well as on model calculations. The results confirm that convective soil air flow is by far the most important source of indoor radon in Finnish low-rise residential housing. (97 refs., 61 figs., 30 tabs.)

  17. Numerical modelling of radon-222 entry into houses: An outline of techniques and results

    DEFF Research Database (Denmark)

    Andersen, C.E.

    2001-01-01

    Numerical modelling is a powerful tool for studies of soil gas and radon-222 entry into houses. It is the purpose of this paper to review some main techniques and results. In the past, modelling has focused on Darcy flow of soil gas (driven by indoor–outdoor pressure differences) and combined...... diffusive and advective transport of radon. Models of different complexity have been used. The simpler ones are finite-difference models with one or two spatial dimensions. The more complex models allow for full three-dimensional and time dependency. Advanced features include: soil heterogeneity, anisotropy......, fractures, moisture, non-uniform soil temperature, non-Darcy flow of gas, and flow caused by changes in the atmospheric pressure. Numerical models can be used to estimate the importance of specific factors for radon entry. Models are also helpful when results obtained in special laboratory or test structure...

  18. Radon as a tracer for soil-gas entry into a house located next to a contaminated dry-cleaning property

    International Nuclear Information System (INIS)

    Andersen, C.E.

    2001-07-01

    This study applies the naturally occurring radioactive gas radon-222 as a tracer for soil-gas entry into a house located next to a dry-cleaners shop. This is possible because the concentration of radon in the soil below the house is about 1000 times higher than the concentration in outdoor air. The study is based on continuous indoor measurement of radon, differential pressures, barometric pressure and temperatures and grab samples of radon below the slab and in the soil in the vicinity of the house. During the investigation, vacuum extraction were used to remove chlorinated solvents (perchloroethylene, PCE) from the unsaturated zone. The study shows that the vacuum extraction influences the radon concentration in and below the house. When the vacuum pump is on, the indoor radon concentration is only 10 Bq/m 3 corresponding to the contribution from radon in outdoor air and exhalation from building materials. When the vacuum pump is set off, the average indoor radon concentration increases to 30 Bq/m 3 . It is believed that the increase is caused by radon entry from the soil. Regression analysis demonstrates that changes in the indoor radon concentration can be explained by changes in indoor-outdoor pressure differences and changes in the atmospheric pressure. This suggests that advection is the primary mode of entry. Under some highly simplifying assumptions the soil-gas entry is found to be around 1 m 3 /h. This, however, is most likely an overestimate. Based on the measured radon concentration in the exhaust air from the vacuum system and a typical radon emanation rate for Danish soil, it is estimated that the soil vapor extraction system ventilates about 10000 m 3 of soil. The investigation is supported by numerical model calculations with the finite-volume model Rnmod3d. (au)

  19. Radon analyser

    International Nuclear Information System (INIS)

    1981-01-01

    The process claimed includes the steps of transferring radon gas produced by a sample to a charcoal trap, cooled to a temperature whereby the radon is absorbed by the charcoal, heating the charcoal trap to a sufficient temperature to release the radon, and transferring the radon to a counting device where the gas particles are counted

  20. Radon soil gas measurements in a geological versatile region as basis to improve the prediction of areas with a high radon potential

    International Nuclear Information System (INIS)

    Kabrt, Franz; Rechberger, Fabian; Schuff, Michael; Seidel, Claudia; Baumgartner, Andreas; Friedmann, Harry; Maringer, Franz Josef

    2014-01-01

    With the aim to predict the radon potential by geological data, radon soil gas measurements were made in a selected region in Styria, Austria. This region is characterised by mean indoor radon potentials of 130-280 Bq m -3 and a high geological diversity. The distribution of the individual measuring sites was selected on the basis of geological aspects and the distribution of area settlements. In this work, the radon soil gas activity concentration and the soil permeability were measured at 100 sites, each with three single measurements. Furthermore, the local dose rate was determined and soil samples were taken at each site to determine the activity concentration of natural radionuclides. During two investigation periods, long-term soil gas radon measurements were made to study the time dependency of the radon activity concentration. All the results will be compared and investigated for correlation among each other to improve the prediction of areas with high radon potential. (authors)

  1. Development of a model for radon concentration in indoor air

    International Nuclear Information System (INIS)

    Jelle, Bjørn Petter

    2012-01-01

    A model is developed for calculation of the radon concentration in indoor air. The model takes into account various important parameters, e.g. radon concentration in ground, radon diffusion resistance of radon barrier, air permeance of ground, air pressure difference between outdoor ground and indoor at ground level, ventilation of the building ground and number of air changes per hour due to ventilation. Characteristic case studies are depicted in selected 2D and 3D graphical plots for easy visualization and interpretation. The radon transport into buildings might be dominated by diffusion, pressure driven flow or a mixture of both depending on the actual values of the various parameters. The results of our work indicate that with realistic or typical values of the parameters, most of the transport of radon from the building ground to the indoor air is due to air leakage driven by pressure differences through the construction. By incorporation of various and realistic values in the radon model, valuable information about the miscellaneous parameters influencing the indoor radon level is gained. Hence, the presented radon model may be utilized as a simple yet versatile and powerful tool for examining which preventive or remedial measures should be carried out to achieve an indoor radon level below the reference level as set by the authorities. - Highlights: ► Model development for calculation of radon concentration in indoor air. ► Radon model accounting for various important parameters. ► Characteristic case studies depicted in 2D and 3D graphical plots. ► May be utilized for examining radon preventive measures.

  2. Radon transport modelling: User's guide to RnMod3d

    International Nuclear Information System (INIS)

    Andersen, C.E.

    2000-08-01

    RnMod3d is a numerical computer model of soil-gas and radon transport in porous media. It can be used, for example, to study radon entry from soil into houses in response to indoor-outdoor pressure differences or changes in atmospheric pressure. It can also be used for flux calculations of radon from the soil surface or to model radon exhalation from building materials such as concrete. The finite-volume model is a technical research tool, and it cannot be used meaningfully without good understanding of the involved physical equations. Some understanding of numerical mathematics and the programming language Pascal is also required. Originally, the code was developed for internal use at Risoe only. With this guide, however, it should be possible for others to use the model. Three-dimensional steady-state or transient problems with Darcy flow of soil gas and combined generation, radioactive decay, diffusion and advection of radon can be solved. Moisture is included in the model, and partitioning of radon between air, water and soil grains (adsorption) is taken into account. Most parameters can change in time and space, and transport parameters (diffusivity and permeability) may be anisotropic. This guide includes benchmark tests based on simple problems with known solutions. RnMod3d has also been part of an international model intercomparison exercise based on more complicated problems without known solutions. All tests show that RnMod3d gives results of good quality. (au)

  3. Radon transport modelling: User's guide to RnMod3d

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, C.E

    2000-08-01

    RnMod3d is a numerical computer model of soil-gas and radon transport in porous media. It can be used, for example, to study radon entry from soil into houses in response to indoor-outdoor pressure differences or changes in atmospheric pressure. It can also be used for flux calculations of radon from the soil surface or to model radon exhalation from building materials such as concrete. The finite-volume model is a technical research tool, and it cannot be used meaningfully without good understanding of the involved physical equations. Some understanding of numerical mathematics and the programming language Pascal is also required. Originally, the code was developed for internal use at Risoe only. With this guide, however, it should be possible for others to use the model. Three-dimensional steady-state or transient problems with Darcy flow of soil gas and combined generation, radioactive decay, diffusion and advection of radon can be solved. Moisture is included in the model, and partitioning of radon between air, water and soil grains (adsorption) is taken into account. Most parameters can change in time and space, and transport parameters (diffusivity and permeability) may be anisotropic. This guide includes benchmark tests based on simple problems with known solutions. RnMod3d has also been part of an international model intercomparison exercise based on more complicated problems without known solutions. All tests show that RnMod3d gives results of good quality. (au)

  4. Determination of the speed of gases in the subsoil by means of method based on the variations of the concentration of the gas radon

    International Nuclear Information System (INIS)

    Garcia Vindas, J.R.

    2001-01-01

    In this paper a theoretic model is proposed to calculate the gas velocity in the subsoil based on radon concentration variations. The general transport equation for radon in a homogeneous soil with constant porosity is assumed. The diffusion coefficient and the gas velocity being constant. In order to illustrate the model, three geological areas were considered: the Irazu and Arenal volcanoes, situated in the volcanic range in costa Rica, and the Agua Caliente fault located in San Jose, Costa Rica. (Author) [es

  5. The effect of an engineered closure cap on radon gas transport from a shallow land burial site

    International Nuclear Information System (INIS)

    Lindstrom, F.T.; Cawlfield, D.E.; Donahue, M.E.; Emer, D.F.; Shott, G.J.

    1992-01-01

    US Department of Energy (DOE) Order 5820.2A requires performance assessment of all new and existing low level radioactive waste disposal sites. An integral part of performance assessment is estimating the fluxes of radioactive gases such as radon-220 and radon-222. Mathematical models, which in themselves point out data needs and therefore drive site characterization, provide a logical means of performing the required flux estimations. The effects of an engineered closure cap on radon gas transport in a very dry alluvial soil in the southwestern desert are considered in detail in this paper. Our model (Lindstrom, et al. 1992 a ampersand b and Cawlfield et al. 1992 a ampersand b) was constructed in a site specific fashion because the existing mathematical models of noble gas transport from the spatial point of origin in the low level waste repository through the surrounding soil and closure cap with subsequent release to the atmosphere are few in numbers (Nazaroff, 1992)

  6. Indoor Radon Concentration Related to Different Radon Areas and Indoor Radon Prediction

    Science.gov (United States)

    Juhásová Šenitková, Ingrid; Šál, Jiří

    2017-12-01

    Indoor radon has been observed in the buildings at areas with different radon risk potential. Preventive measures are based on control of main potential radon sources (soil gas, building material and supplied water) to avoid building of new houses above recommended indoor radon level 200 Bq/m3. Radon risk (index) estimation of individual building site bedrock in case of new house siting and building protection according technical building code are obligatory. Remedial actions in buildings built at high radon risk areas were carried out principally by unforced ventilation and anti-radon insulation. Significant differences were found in the level of radon concentration between rooms where radon reduction techniques were designed and those where it was not designed. The mathematical model based on radon exhalation from soil has been developed to describe the physical processes determining indoor radon concentration. The model is focused on combined radon diffusion through the slab and advection through the gap from sub-slab soil. In this model, radon emanated from building materials is considered not having a significant contribution to indoor radon concentration. Dimensional analysis and Gauss-Newton nonlinear least squares parametric regression were used to simplify the problem, identify essential input variables and find parameter values. The presented verification case study is introduced for real buildings with respect to various underground construction types. Presented paper gives picture of possible mathematical approach to indoor radon concentration prediction.

  7. Radon transport modelling: User's guide to RnMod3d

    DEFF Research Database (Denmark)

    Andersen, Claus Erik

    2000-01-01

    RnMod3d is a numerical computer model of soil-gas and radon transport in porous media. It can be used, for example, to study radon entry from soil into houses in response to indoor-outdoor pressure differences or changes in atmospheric pressure. It canalso be used for flux calculations of radon...... decay, diffusion and advection of radon can be solved. Moisture is included in the model, and partitioning ofradon between air, water and soil grains (adsorption) is taken into account. Most parameters can change in time and space, and transport parameters (diffusivity and permeability) may...... be anisotropic. This guide includes benchmark tests based on simpleproblems with known solutions. RnMod3d has also been part of an international model intercomparison exercise based on more complicated problems without known solutions. All tests show that RnMod3d gives results of good quality....

  8. Hierarchical modeling of indoor radon concentration: how much do geology and building factors matter?

    International Nuclear Information System (INIS)

    Borgoni, Riccardo; De Francesco, Davide; De Bartolo, Daniela; Tzavidis, Nikos

    2014-01-01

    Radon is a natural gas known to be the main contributor to natural background radiation exposure and only second to smoking as major leading cause of lung cancer. The main concern is in indoor environments where the gas tends to accumulate and can reach high concentrations. The primary contributor of this gas into the building is from the soil although architectonic characteristics, such as building materials, can largely affect concentration values. Understanding the factors affecting the concentration in dwellings and workplaces is important both in prevention, when the construction of a new building is being planned, and in mitigation when the amount of Radon detected inside a building is too high. In this paper we investigate how several factors, such as geologic typologies of the soil and a range of building characteristics, impact on indoor concentration focusing, in particular, on how concentration changes as a function of the floor level. Adopting a mixed effects model to account for the hierarchical nature of the data, we also quantify the extent to which such measurable factors manage to explain the variability of indoor radon concentration. - Highlights: • It is assessed how the variability of indoor radon concentration depends on buildings and lithologies. • The lithological component has been found less relevant than the building one. • Radon-prone lithologies have been identified. • The effect of the floor where the room is located has been estimated. • Indoor radon concentration have been predicted for different dwelling typologies

  9. The Radon Gas in Underground Buildings in Clay Soils. The Plaza Balmis Shelter as a Paradigm.

    Science.gov (United States)

    Rizo Maestre, Carlos; Echarri Iribarren, Víctor

    2018-05-17

    In healthy buildings, it is considered essential to quantify air quality. One of the most fashionable indicators is radon gas. To determine the presence of this element, which is harmful to health, in the environment, the composition of the soil is studied. The presence of radon gas within a building depends both on the terrain in which it is located and on the composition of the materials of which it is composed, and not as was previously believed, only by the composition of the soil (whether granitic or not). Many countries are currently studying this phenomenon, including Spain where the building regulations regarding the accumulation of radon gas, do not list in their technical codes, the maximum dose that can a building can hold so that it is not harmful to people and the measures to correct excessive accumulation. Therefore, once the possible existence of radon in any underground building has been verified, regardless of the characteristics of the soil, the importance of defining and unifying the regulations on different levels of radon in all architectural constructions is evident. Medical and health science agencies, including the World Health Organization, consider that radon gas is a very harmful element for people. This element, in its gaseous state, is radioactive and it is present in almost soils in which buildings are implanted. Granitic type soils present higher levels of radon gas. Non-granitic soils have traditionally been considered to have very low radon levels. However, this paper demonstrates the relevant presence of radon in non-granitic soils, specifically in clayey soils, by providing the results of research carried out in the underground air raid shelter at Balmis Square in Alicante (Spain). The results of the measurements of radon accumulation in the Plaza Balmis shelter are five times higher than those obtained in a similar ungrounded building. This research addresses the constructive typology of an under-ground building and the radon

  10. Radon in a Karstic Region School: Concentrations in Soil Gas and Indoors

    International Nuclear Information System (INIS)

    Vaupotic, J.; Kobal, I.; Barisic, D.; Lulic, S.

    1998-01-01

    The school presented in this paper exceeded instantaneous indoor radon concentration of 1000 Bqm -3 , obtained within the Slovene radon programme. Thus, additional measurements were performed and the radiation doses of teachers and pupils estimated. Radon concentrations between 1000 and 3000 Bqm -3 during teaching hours were found and the yearly effective doses from 0.75 to 1.1 mSv for the pupils and from 1.1 to 4.2 mSv for the teachers were calculated. In the soil gas radon and thoron concentration ranging from 70 to 150 kBqm -3 were obtained. The school was mitigated during summer 1998. (author)

  11. Hazardous waste disposal in relationship to radon gas emanation in atmosphere

    International Nuclear Information System (INIS)

    Fang, H.Y.

    1990-01-01

    Radioactive/toxic radon gas (Rn) produced naturally in the ground by the normal decay of uranium (U) and radium (Ra) is widely distributed in trace amounts in the earth's crust. It is a colorless, odorless and tasteless element and is one of the six generally known noble gases which are inert gases lacking the usual or anticipated chemical or biological action. Most radon gas is concentrated in the oxidation belt which is at a relatively shallow depth from the ground surface. Under normal conditions, the amount of radon gas seeping into the atmosphere or entering into residential buildings is very little and will not be harmful to human health. In recent years, due to population growth, a progressive living standard and industrial progress, many natural farm lands, forests and wetlands have been destroyed by conversion into residential and industrial compounds; consequently, such construction activities and industrial waste disposal changes the dynamic equilibrium of the ecosystem which can trigger and accelerate radon gas emanation and mobilization. This change is the major reason for the problem of indoor radon concentration which has significantly increased in recent years. Recent findings indicate that radon is not a totally inert element as previously thought. It can be influenced by local environments such as temperature, pH value, ion exchange, redox reaction, etc. to some degree. Also radon gas interacts with soil, water, air and others; unfortunately, the interface mechanisms between radon and the environment are not yet clearly understood and little information on these aspects is available. In this paper only the hazardous waste disposal causes for radon emanation are discussed. To deal with such complex phenomena, a new approach is presented that assumes radon gas interaction with the environment through dust in the air and suspensions in the water and soil-water system

  12. Development and application of a model to calculate the distribution of radon in houses

    International Nuclear Information System (INIS)

    Haider, B.; Papamokos, E.; Ferron, G.; Peter, J.; Unverfaerth, L.

    1990-01-01

    In order to produce a radon profile of the examined houses, an electronic measuring process was used to determine the concentration of radon decomposition products. The measurements were made inside flats with the doors closed, in vertical air exchange between the cellars and the storeys of houses and in the cellar itself. The measured decomposition product and measured gas concentrations show that, apart from the cellar floor, part of the building material makes a considerable contribution to emanation of radon and thoron. It was found that a model for calculating the loading of the inhabitants of a house with radon is not yet available due to the complicated flat geometry and the activities of the inhabitants. (DG) [de

  13. Radiation exposure and radon levels in some stations of the Syrian gas company

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Shwekani, R.; Jerbi, B.; Awad, I.

    2006-06-01

    In the present study, exposure levels and radon concentrations have been measured in natural gas production lines at the Syrian gas company. The study area includes gas stations for directories of Der Ezzor, Al-Jbessa, Al-Hassaka, and the middle region. The results showed that radiation exposure rates in remote stations and internal stations were within the natural levels except for two main locations, viz reflex pumps and propane production unites; 3 μSvhr -1 was reported. Radon concentration in Syrian natural gas varied between 15.4 Bqm - 3 and 1141 Bqm - 3; coproduced natural gas was found to contain higher concentration that the free natural gas. In addition, radon concentrations were higher in the central processing facilities that the well heads; these high levels are due to pressurizing and concentrating processes that enhance radon gas and its daughters concentrations in these stations. Moreover, a value of 659 Bqm - 3 in Al-Jbessa directorate gas and 225 Bqm - 3 in Al-Hassaka directorate gas were reported. While the concentration was lower in gas producing safur; a value of 80 Bqm - 3 was observed. On the other hand, maximum radon gas concentrations and its daughters in workplace air environment was found to be relatively high in the gas analysis laboratory and they are due to gas release inside the lab during analysis in addition to good separation of these laboratories from the surrounding environment. (author)

  14. Development of the charcoal adsorption technique for determination of radon content in natural gas

    International Nuclear Information System (INIS)

    Paewpanchon, P.; Chanyotha, S.

    2017-01-01

    A technique for the determination of the radon concentration in natural gas using charcoal adsorption has been developed to study the effects of parameters that influence the adsorption efficiency of radon onto activated charcoal. Several sets of experiments were conducted both in the laboratory and in an actual natural gas field for comparison. The results show that the adsorption capability of radon onto activated charcoal varies inversely with temperature, hydrocarbon concentration and the humidity contained within the natural gas. A technique utilizing dry ice as a coolant was found to be the most effective for trapping radon in natural gas samples at the production site. A desiccant can be used to remove moisture from the sampling gas. The technique described here increases the adsorption efficiency of activated charcoal by 10-20% compared to our previous study. (authors)

  15. DEVELOPMENT OF THE CHARCOAL ADSORPTION TECHNIQUE FOR DETERMINATION OF RADON CONTENT IN NATURAL GAS.

    Science.gov (United States)

    Paewpanchon, P; Chanyotha, S

    2017-11-01

    A technique for the determination of the radon concentration in natural gas using charcoal adsorption has been developed to study the effects of parameters that influence the adsorption efficiency of radon onto activated charcoal. Several sets of experiments were conducted both in the laboratory and in an actual natural gas field for comparison. The results show that the adsorption capability of radon onto activated charcoal varies inversely with temperature, hydrocarbon concentration and the humidity contained within the natural gas. A technique utilizing dry ice as a coolant was found to be the most effective for trapping radon in natural gas samples at the production site. A desiccant can be used to remove moisture from the sampling gas. The technique described here increases the adsorption efficiency of activated charcoal by 10-20% compared to our previous study. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Soil gas and radon entry potential measurements in central Florida houses

    International Nuclear Information System (INIS)

    Turk, B.H.

    1993-01-01

    A technique to quantify the various parameters associated with the pressure-driven entry rate of soil gas and radon into buildings has been applied to five central Florida houses with slab-on-grade construction. Results indicate that the slabs of these Florida houses are more resistant to soil gas flow than slabs in previously studied New Jersey and New Mexico houses. The data for locations near the slab perimeter show that the resistance to soil gas flow is greater for the slab than for the underlying materials/soils, implying that the slab resistance is a slightly dominant factor controlling soil gas entry in these houses. As in the New Jersey and New Mexico houses, soil gas and radon entry potentials were highest near the slab perimeters. In contrast to the earlier studies, geometric mean radon entry potentials did not correlate well with measured indoor radon levels. (orig.). (4 refs., 1 fig., 2 tabs.)

  17. Radiation doses due to natural radon gas releases from the final disposal facility of spent fuel

    International Nuclear Information System (INIS)

    Vesterbacka, K.; Arvela, H.

    1998-03-01

    Building an underground repository for the spent nuclear fuel increases releases of natural radon gas. In the report the radon releases, the resulting doses as well as the radon concentration in the repository air are investigated. There are four optional building locations for the underground repository and three different strategies of construction. Optional sites are Olkiluoto of Eurajoki, Romuvaara of Kuhmo, Haestholmen of Loviisa and Kivetty of Aeaenekoski. The most significant radon sources in the underground repository are the rockwalls and the groundwater leaking to the repository. High groundwater radon concentrations can increase significantly radon concentration in the repository air despite the groundwater leak rate is low. The radon source strength from the rockwalls, groundwater and macadam spreaded on the floor of the repository is estimated in this report. Using these results the radon concentration in the repository is calculated for several air exchange rates. Data from petrological studies performed at the optional building sites as well as the measurement data of the Radiation and Nuclear Safety Authority has been utilized. Rough approximations were needed when estimating the radon source strength. The estimated total radon source strength varies between 1 - 600 MBq/h depending on the repository construction strategy. Repository indoor air radon concentration with no air exchange varies between 0,7 - 120 kBq/m 3 . Using the most probable estimates on radon source strength, the allowed indoor radon concentration of 400 Bq/m 3 at workplaces is achieved by using the air exchange rate of 0,5 l/h in every optional repository. Repository exhaust air and the pile of macadam increases the radon levels in the environment. The radiation dose to the critical person depends on the open volume of the repository. The annual radiation dose calculated from the most probable radon source strength at the distance of 500 metres is below 0,005 mSv at all sites

  18. Domestic gas contribution to natural radon concentration in Paraguay

    International Nuclear Information System (INIS)

    Coronel, G.; Sajo B, L.

    1996-01-01

    The technique for measuring the concentration of radon in gas sold commercially for domestic use is presented. It is shown that the contribution is not significant, 5.5±1.4 (Bq/m 3 ), nevertheless it could reach in some cases significant values of intervention (200 Bq/m 3 ). The results indicate that the additional dose to which the population is exposed is approximately 26% of the natural background calculated in approximately 0,28 mSv/year. By assuming a lineal proportionality between dose and risk, the increase of the possibility of catching lethal leukemia or cancer is 16 cases for every million of population. (authors). 8 refs., 1 fig

  19. Modeling radon entry into Florida slab-on-grade houses

    International Nuclear Information System (INIS)

    Revzan, K.L.; Fisk, W.J.; Sextro, R.G.

    1993-01-01

    Radon entry into a Florida house whose concrete slab is supported by a permeable concrete-block stem wall and a concrete footer is modeled. The slab rests on backfill material; the same material is used to fill the footer trench. A region of undisturbed soil is assumed to extend 10 m beyond and below the footer. The soil is assumed homogeneous and isotropic except for certain simulations in which soil layers of high permeability or radium content are introduced. Depressurization of the house induces a pressure field in the soil and backfill. The Laplace equation, resulting from Darcy's law and the continuity equation, is solved using a steady-state finite-difference model to determine this field. The mass-transport equation is then solved to obtain the diffusive and advective radon entry rates through the slab; the permeable stem wall; gaps at the intersections of the slab, stem wall, and footer; and gaps in the slab. These rates are determined for variable soil, backfill, and stem-wall permeability and radium content, slab-opening width and position, slab and stem-wall diffusivity, and water table depth. The variations in soil permeability and radium content include cases of horizontally stratified soil. We also consider the effect of a gap between the edge of the slab and the stem wall that restricts the passage of soil gas from the stem wall into the house. Calculations indicate that the total radon entry rate is relatively low unless the soil or backfill permeability or radium content is high. Variations in most of the factors, other than the soil permeability and radium content, have only a small effect on the total radon entry rate. However, for a fixed soil permeability, the total radon entry rate may be reduced by a factor of 2 or more by decreasing the backfill permeability, by making the stem wall impermeable and gap-free, (possibly by constructing a one-piece slab/stem-wall/footer), or by increasing the pressure in the interior of the stem wall

  20. Sex and smoking sensitive model of radon induced lung cancer

    International Nuclear Information System (INIS)

    Zhukovsky, M.; Yarmoshenko, I.

    2006-01-01

    Radon and radon progeny inhalation exposure are recognized to cause lung cancer. Only strong evidence of radon exposure health effects was results of epidemiological studies among underground miners. Any single epidemiological study among population failed to find reliable lung cancer risk due to indoor radon exposure. Indoor radon induced lung cancer risk models were developed exclusively basing on extrapolation of miners data. Meta analyses of indoor radon and lung cancer case control studies allowed only little improvements in approaches to radon induced lung cancer risk projections. Valuable data on characteristics of indoor radon health effects could be obtained after systematic analysis of pooled data from single residential radon studies. Two such analyses are recently published. Available new and previous data of epidemiological studies of workers and general population exposed to radon and other sources of ionizing radiation allow filling gaps in knowledge of lung cancer association with indoor radon exposure. The model of lung cancer induced by indoor radon exposure is suggested. The key point of this model is the assumption that excess relative risk depends on both sex and smoking habits of individual. This assumption based on data on occupational exposure by radon and plutonium and also on the data on external radiation exposure in Hiroshima and Nagasaki and the data on external exposure in Mayak nuclear facility. For non-corrected data of pooled European and North American studies the increased sensitivity of females to radon exposure is observed. The mean value of ks for non-corrected data obtained from independent source is in very good agreement with the L.S.S. study and Mayak plutonium workers data. Analysis of corrected data of pooled studies showed little influence of sex on E.R.R. value. The most probable cause of such effect is the change of men/women and smokers/nonsmokers ratios in corrected data sets in North American study. More correct

  1. Sex and smoking sensitive model of radon induced lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zhukovsky, M.; Yarmoshenko, I. [Institute of Industrial Ecology of Ural Branch of Russian Academy of Sciences, Yekaterinburg (Russian Federation)

    2006-07-01

    Radon and radon progeny inhalation exposure are recognized to cause lung cancer. Only strong evidence of radon exposure health effects was results of epidemiological studies among underground miners. Any single epidemiological study among population failed to find reliable lung cancer risk due to indoor radon exposure. Indoor radon induced lung cancer risk models were developed exclusively basing on extrapolation of miners data. Meta analyses of indoor radon and lung cancer case control studies allowed only little improvements in approaches to radon induced lung cancer risk projections. Valuable data on characteristics of indoor radon health effects could be obtained after systematic analysis of pooled data from single residential radon studies. Two such analyses are recently published. Available new and previous data of epidemiological studies of workers and general population exposed to radon and other sources of ionizing radiation allow filling gaps in knowledge of lung cancer association with indoor radon exposure. The model of lung cancer induced by indoor radon exposure is suggested. The key point of this model is the assumption that excess relative risk depends on both sex and smoking habits of individual. This assumption based on data on occupational exposure by radon and plutonium and also on the data on external radiation exposure in Hiroshima and Nagasaki and the data on external exposure in Mayak nuclear facility. For non-corrected data of pooled European and North American studies the increased sensitivity of females to radon exposure is observed. The mean value of ks for non-corrected data obtained from independent source is in very good agreement with the L.S.S. study and Mayak plutonium workers data. Analysis of corrected data of pooled studies showed little influence of sex on E.R.R. value. The most probable cause of such effect is the change of men/women and smokers/nonsmokers ratios in corrected data sets in North American study. More correct

  2. Radon

    International Nuclear Information System (INIS)

    Holmen, R.W.

    1987-01-01

    The discovery that radon enters into residential and commercial structures and produces adverse health consequences to occupants thereof has raised issues for the real estate profession in connection with transactions involving affected structures. The legal responsibilities of real estate professionals in relation to such structures have not yet been clearly defined. Moreover, consistent and reliable testing methods and results, clear identification of circumstances where testing is necessary, and consensus as to health risks suggested by various radon levels have yet to be achieved. When these legal and technical questions are clarified, real estate buyer and sellers as well as agents and brokers will be greatly benefited

  3. Experimental, statistical, and biological models of radon carcinogenesis

    International Nuclear Information System (INIS)

    Cross, F.T.

    1991-09-01

    Risk models developed for underground miners have not been consistently validated in studies of populations exposed to indoor radon. Imprecision in risk estimates results principally from differences between exposures in mines as compared to domestic environments and from uncertainties about the interaction between cigarette-smoking and exposure to radon decay products. Uncertainties in extrapolating miner data to domestic exposures can be reduced by means of a broad-based health effects research program that addresses the interrelated issues of exposure, respiratory tract dose, carcinogenesis (molecular/cellular and animal studies, plus developing biological and statistical models), and the relationship of radon to smoking and other copollutant exposures. This article reviews experimental animal data on radon carcinogenesis observed primarily in rats at Pacific Northwest Laboratory. Recent experimental and mechanistic carcinogenesis models of exposures to radon, uranium ore dust, and cigarette smoke are presented with statistical analyses of animal data. 20 refs., 1 fig

  4. Modeling ventilation and radon in new dutch dwellings

    International Nuclear Information System (INIS)

    Janssen, M.P.M.

    2003-01-01

    Indoor radon concentrations were estimated for various ventilation conditions, the differences being mainly related to the airtightness of the dwelling and the ventilation behavior of its occupants. The estimations were aimed at describing the variation in air change rates and radon concentrations to be expected in the representative newly built Dutch dwellings and identifying the most important parameters determining air change rate and indoor radon concentration. The model estimations were compared with measurements. Most of the air was predicted to enter the model dwelling through leaks in the building shell, independent of the ventilation conditions of the dwelling. Opening the air inlets was shown to be an efficient way to increase infiltration and thus to decrease radon concentration. The effect of increasing the mechanical ventilation rate was considerably less than opening the air inlets. The mechanical ventilation sets the lower limit to the air change rate of the dwelling, and is effective in reducing the radon concentration when natural infiltration is low. Opening inside doors proved to be effective in preventing peak concentrations in poorly ventilated rooms. As the airtightness of newly built dwellings is still being improved, higher radon concentrations are to be expected in the near future and the effect of occupant behavior on indoor radon concentrations is likely to increase. According to the model estimations soil-borne radon played a moderate role, which is in line with measurements. (au)

  5. Is the Health of Irish Workers adequately protected from the effects Radon Gas?

    International Nuclear Information System (INIS)

    Heery Mary

    2006-08-01

    Since the introduction of the workplace ban on smoking in March, 2004 radon is the most significant factor for lung cancer in the workplace in Ireland. Radon is a natural radioactive invisible gas which accounts for over 60% of the total radiation dose received in Ireland. It has been classified as a Group One carcinogen by the World Health Organisation and is the second most important risk factor for lung cancer worldwide, after tobacco smoking. Lung cancer is the most common type of cancer causing death in Ireland. The Radiological Protection Institute of Ireland estimate that there are approximately 200 deaths per year in Ireland linked to radon. The aim of this study was to determine if the health of Irish workers was being protected from the effects of radon gas. Indoor workplaces in Sligo and Ballina, two towns in High Radon Areas were surveyed, to assess awareness of, and compliance with the legislation governing radon in the workplace. The results show that of employers surveyed: at least 50% did not know that their workplace was located in a High Radon Areas, 43% were not aware of the legislation governing radon in the workplace, 48% had not identified radon as a hazard to health and safety, 64% had not included radon in the workplace Safety Statement and 58% had not carried out a measurement for radon. The results also show that: awareness and compliance was higher in Public Sector workplaces than in Private Sector workplaces, it was higher among larger employers with an international profile than among smaller local employers, employers knew where to go to for advice and guidance on carrying out radon surveys in the workplace, advice on radon was not readily available from State bodies like the Health and Safety Authority, Local Authorities and the Health Service Executive. In conclusion, more than half of all employers surveyed were failing to comply with legislation governing radon in the workplace, yet no employer in either town had ever been

  6. Development and evaluation of global radon transport model

    International Nuclear Information System (INIS)

    Kojima, H.; Nagano, K.

    2003-01-01

    The radioactive noble gas Radon-222 ( 222 Rn) is chemically inert and is removed only by radioactive decay (T1/2=3.8 d). Its primary source is uniformly distributed over the continents and the ocean represents a secondary source of atmospheric 222 Rn. The strong contrast in source strength between continents and the ocean makes 222 Rn an ideal marker of continental air masses. Because of its simple properties, the temporal and spatial distribution of 222 Rn in the troposphere is straightforward to simulate by means of atmospheric transport models. The simulation provides an intuitive visualization of the complex transport characteristics and more definite proof of phenomenon. In this paper, we present the results of an exploratory study, in which we investigated the performance of a three-dimensional transport model of the global troposphere in simulating the long range transport of 222 Rn. The transport equation has been solved by a numerical procedure based on some boundary conditions. The model structure which we have originally developed, has a horizontal resolution of 2.5deg in latitude and 2.5deg in longitude, and 10 layers in the vertical dimension. The basic computational time step used in the model runs was set to 5 min. The simulations described in this article were performed by means of a transport model driven by global objective analytical data of a time resolution of 6 h, supplied by the Japan Meteorological Agency. We focus on the west of North Pacific Ocean, were the influence of air pollution from an Asian Continent and the Japan Islands was received. For simulation experiments, radon data from some shipboard measurements on the North Pacific Ocean have been used in the present study. Figure shows time series of model prediction with different latitude distributions of radon exhalation rate and measured radon data. We find that our model consistently produce the observation. We will discuss the characteristics of the temporal and special

  7. Environmental assessment of indoor radon gas exposure health hazards and some of its public risks

    International Nuclear Information System (INIS)

    Hussein, Abd El-Razik. Z.; Ibrahim, M.Se.; Ragab, M.H.; El-Bukhari, M.S.

    2005-01-01

    This study examine the relationship between indoor radon gas exposure and the cancer risk and housing characteristics in lung cancer risk houses (CRH) compared to non lung cancer risk houses (NCRH). Mean radon concentrations measured by active method were significantly higher among CRH compared to NCRH, 9:93 pCi/L versus 4.56 pCi/L, respectively. There was no statistically significant diurnal variation as regards radon levels in all examined houses. Indoor radon concentrations show statistically significance in houses with bad ventilation (low air change rate) compared to houses with good ventilation (high air change rate). Houses with floor material of tiles, had statistically significant higher radon concentrations. Neither finishing wall material nor indoor gas source shows statistically significance as regard radon levels. Radon levels > 4 pCi/L (US EPA action level) were statistically significance higher in bed rooms compared levels in living rooms. High radon concentrations were reported in lung cane risk houses and in houses with bad ventilation

  8. Radon occurrence in soil-gas and groundwater around an active landslide

    Energy Technology Data Exchange (ETDEWEB)

    Ramola, R.C. [Department of Physics, H.N.B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal -249 199 (India)], E-mail: rcramola@gmail.com; Choubey, V.M. [Wadia Institute of Himalayan Geology, Dehradun 248 001 (India); Negi, M.S.; Prasad, Yogesh; Prasad, Ganesh [Department of Physics, H.N.B. Garhwal University, Badshahi Thaul Campus, Tehri Garhwal -249 199 (India)

    2008-01-15

    This paper presents the results of investigation of radon levels in the soil-gas and groundwater of Uttarkashi, India within the distance of 5 km in vertical and horizontal directions from the landslide of Varunawat hill. Radon release from the soil and groundwater was found higher than the normal values. Radon concentration in groundwater over and around the landslide was found to vary from 0.51 to 86kBqm{sup -3}. The soil-gas radon concentration was found to vary from 219 to 3kBqm{sup -3} along the slope of landslide. Radon exhalation rate in collected soil samples was found to vary from 2.28x10{sup -5} to 9.01x10{sup -5}Bqkg{sup -1}h{sup -1}. Radon values were not found correlated with major and trace element contents in the upper soil of the area, which indicate that the migration of radon from deeper part of the earth along with landslide contribute to the surface radon concentration. Recorded values show a close association with local geology and Varunawat eruptions.

  9. Radon occurrence in soil-gas and groundwater around an active landslide

    International Nuclear Information System (INIS)

    Ramola, R.C.; Choubey, V.M.; Negi, M.S.; Prasad, Yogesh; Prasad, Ganesh

    2008-01-01

    This paper presents the results of investigation of radon levels in the soil-gas and groundwater of Uttarkashi, India within the distance of 5 km in vertical and horizontal directions from the landslide of Varunawat hill. Radon release from the soil and groundwater was found higher than the normal values. Radon concentration in groundwater over and around the landslide was found to vary from 0.51 to 86kBqm -3 . The soil-gas radon concentration was found to vary from 219 to 3kBqm -3 along the slope of landslide. Radon exhalation rate in collected soil samples was found to vary from 2.28x10 -5 to 9.01x10 -5 Bqkg -1 h -1 . Radon values were not found correlated with major and trace element contents in the upper soil of the area, which indicate that the migration of radon from deeper part of the earth along with landslide contribute to the surface radon concentration. Recorded values show a close association with local geology and Varunawat eruptions

  10. Nuclear tracks in solids and gas radon measurements

    International Nuclear Information System (INIS)

    Espinosa, G.

    2007-01-01

    Full text: The Department of Energy (DOE), the Environmental Protection Agency (EPA) in USA, and the European Community, have dedicated significant budget to the Radon study, its health effects and remedial actions for controlling and achieving lower levels, in these cases, nationwide research programs have been organized. With the aim to contribute on the radon levels knowledge in our country, the Applied Dosimetry Project at the Physics Institute of the University of Mexico has developed an indoor and outdoor radon measurement methodology. In this paper a passive radon detector device based on CR-39 polycarbonate for use in radon research and routine measurements is presented. As well the methodology for the track formation, automatic reading system, calibration procedure and measurements in a different location, are shown in this work. The results had been compared with dynamic detection systems, and another methodologies and research groups in order to have a high confidence in the radon levels reported. (Author)

  11. A technical evaluation of the EDA radon gas continuous monitoring system

    International Nuclear Information System (INIS)

    Bigu, J.

    1979-04-01

    Extensive laboratory and underground tests were conducted with a radon gas continuous monitoring system built by EDA Instruments Inc. The system consists of several remote radon gas sensors linked via signal cables to a central control unit that fully controls the operation of the radon monitors. The system enables four operations to be performed: sampling, background, flush and bypass. The sequence and duration of these functions is programmable. Up to 20 functions in any desired pattern each lasting from 1 min to 23 hr 59 min can be programmed. Several programs were used during the experiments in order to obtain radon and thoron gas levels. The performance of the EDA system was quite satisfactory. It is suggested that ruggedization as well as some other modifications be introdouced into the system to: a) better withstand the harsh underground environment; and b) improve its performance

  12. Survey on the radon gas content and surface gamma radiometry in the cape Fort William area

    International Nuclear Information System (INIS)

    Fajardo, Marco

    1998-01-01

    The Ecuadorian Commission of Atomic Energy, during the last years have carried out investigations on the presence of Radon in the Ecuador with a numberless of purposes: radon in polluted spaces, contamination of radon in mining work, radon applied to detection of uranium and exploration of uranium, getting outputs that in their due moment have been published in several reports through the CEEA. Within the Antarctic Ecuadorian Program, it was expounded carry out investigation, on the presence of the gas radon and superficial gamma radiometry in pint Fort William. This study enlarges to the Bransfield Strait, utilizing portable equipment, and allowed to carry out studies in inhospitable zones, where an infrastructure does not exist in order to could employ more complex equipment. The bank of data gotten on radiometry and emanometry will apply to fields of radioprotection, geophysics and geology

  13. Risk assessment of radon gas concentration for some selected offices of KNUST campus, Kumasi

    International Nuclear Information System (INIS)

    Bediako, Yaw Addo

    2013-11-01

    Radon (Rn-222) has been identified as an factor that could result in a health hazard by studies all around the world. The health risks can be minimised by preventing measures where radon is highly concentrated as in some mines or homes or offices. A study in the buildup concentration of the inert gas, will give us a better understanding of its possible pathways through soil into the air surrounding and offices where radon releases can become hazardous. Measuring the radon concentrations on campus, can help to deduce the radon flux to identify the problem areas for rehabilitation. An active method incorporating Trace level radon gas detection and continious monitoring method was used in this study to determine the radon concentration of the selected offices. Concentrations ranging from 0.010 to 0.498 pCi/I were detected, with the head of optometry and Visual Science recording the highest concentration of 0.498 pCi/I, while the head of Agricultural Engineering Department office with the least concentration of 0.010 pCi/I. Although these concentrations are generally low as compared with the EPA guidelines of an action level of 4 pCi/I, but no amount of radiation is said to be safe. (au)

  14. Transport of Radon Gas into a Tunnel at Yucca Mountain-Estimating Large-Scale Fractured Tuff Hydraulic Properties and Implications for the Operation of the Ventilation System

    International Nuclear Information System (INIS)

    Unger, A.; Finsterle, S.; Bodvarsson, G.

    2003-01-01

    Radon gas concentrations have been monitored as part of the operation of a tunnel (the Exploratory Studies Facility-ESF) at Yucca Mountain to ensure worker safety. The objective of this study was to examine the potential use of the radon data to estimate large-scale formation properties of fractured tuffs. This objective was examined by developing a numerical model, based upon the characteristics of the ESF and the Topopah Spring welded (TSw) tuff unit, capable of predicting radon concentrations for prescribed ventilation conditions. The model was used to address two specific issues. First, it was used to estimate the permeability and porosity of the fractures in the TSw at the length scale of the ESF and extending tens of meters into the TSw, which surrounds the ESF. Second, the model was used to understand the mechanism leading to radon concentrations exceeding a specified level within the ESF. The mechanism controlling radon concentrations in the ESF is a function of atmospheric barometric fluctuations being propagated down the ESF along with ventilated air flow and the slight suction induced by the ventilation exhaust fans at the South Portal of the ESF. These pressure fluctuations are dampened in the TSw fracture continuum according to its permeability and porosity. Consequently, as the barometric pressure in the ESF drops rapidly, formation gases from the TSw are pulled into the ESF, resulting in an increase in radon concentrations. Model calibration to both radon concentrations measured in the ESF and gas-phase pressure fluctuations in the TSw yielded concurrent estimates of TSw fracture permeability and porosity of l x 10 -11 m 2 and 0.00034, respectively. The calibrated model was then used as a design tool to predict the effect of adjusting the current ventilation-system operation strategy for reducing the probability of radon gas concentrations exceeding a specified level

  15. Identification of radon anomalies in soil gas using decision trees and neural networks

    International Nuclear Information System (INIS)

    Zmazek, B.; Dzeroski, S.; Torkar, D.; Vaupotic, J.; Kobal, I.

    2010-01-01

    The time series of radon ( 222 Rn) concentration in soil gas at a fault, together with the environmental parameters, have been analysed applying two machine learning techniques: (I) decision trees and (II) neural networks, with the aim at identifying radon anomalies caused by seismic events and not simply ascribed to the effect of the environmental parameters. By applying neural networks, 10 radon anomalies were observed for 12 earthquakes, while with decision trees, the anomaly was found for every earthquake, but, undesirably, some anomalies appeared also during periods without earthquakes. (authors)

  16. Radon decay product in-door behaviour - parameter, measurement method, and model review

    International Nuclear Information System (INIS)

    Scofield, P.

    1988-01-01

    This report reviews parameters used to characterize indoor radon daughter behavior and concentrations. Certain parameters that affect indoor radon daughter concentrations are described and the values obtained experimentally or theoretically are summarized. Radon daughter measurement methods are reviewed, such as, PAEC, unattached daughters, particle size distributions, and plateout measurement methods. In addition, certain radon pressure driven/diffusion models and indoor radon daughter models are briefly described. (orig.)

  17. Mathematical models for indoor radon prediction

    International Nuclear Information System (INIS)

    Malanca, A.; Pessina, V.; Dallara, G.

    1995-01-01

    It is known that the indoor radon (Rn) concentration can be predicted by means of mathematical models. The simplest model relies on two variables only: the Rn source strength and the air exchange rate. In the Lawrence Berkeley Laboratory (LBL) model several environmental parameters are combined into a complex equation; besides, a correlation between the ventilation rate and the Rn entry rate from the soil is admitted. The measurements were carried out using activated carbon canisters. Seventy-five measurements of Rn concentrations were made inside two rooms placed on the second floor of a building block. One of the rooms had a single-glazed window whereas the other room had a double pane window. During three different experimental protocols, the mean Rn concentration was always higher into the room with a double-glazed window. That behavior can be accounted for by the simplest model. A further set of 450 Rn measurements was collected inside a ground-floor room with a grounding well in it. This trend maybe accounted for by the LBL model

  18. Radon in soil gas in the metropolitan region of Belo Horizonte, Brazil

    International Nuclear Information System (INIS)

    Teixeira, Giane Gariglio; Rocha, Zildete

    2007-01-01

    Radon, the natural radioactive gas is produced by the radioactive decay of uranium and thorium which are ubiquitous, specially in rock and soil. By diffusion and convection. Radon migrate from the rocks and to the groundwater and to the soil and from them the radon migrate through fissures, pipes and hales to the surface. Measurements were carried out in the Metropolitan Region of Belo Horizonte, whose greatest part of the in habitants occupies the great pre cambrian unit of the Iron Quadrangle of Minas Gerais denominated 'Granitic Gneissic Complex', composed of Archean rocks of age between 3,2 Ga and 2,6 Ga. The part in which occurs in the municipal area of Belo Horizonte was denominated as Complexo Belo Horizonte, whose most characteristics rocks named Gneiss Belo Horizonte. The soil gas radon concentrations were determined by using a samples and a continuos flow through ionization chamber detector AlphaGUARD PQ2000PRO - Genitron Instruments GmbH in a Instrumental Neutron Activation Analysis). Most results of radon concentration soil gas were in the range 10 kBq/m 3 to 50 kBq/m 3 . This values, according to the established Swedish Criteria are normal risk values. For soils classified as normal risk require 'radon protective construction', but the necessity of mitigation actions will depend on other factors, for example the soil permeability and rock type. (author)

  19. Development of model DTY-104 radon measuring meter

    International Nuclear Information System (INIS)

    Shi Zhixia; Zhang Aiming; Li Yachun; Wang Qingheng

    2000-01-01

    Model DTY-104 radon measuring meter is an improvement on Model DTY-103. 'Difference value method' is used, which has been strictly developed and makes the radon exhalation rate more accurate, instead of using 'simplified difference value method'. The electronic circuit is redesigned and 80C31 single chip processor is used, which makes the operation more convenient and the function strengthened. In a more reasonable manner, the humidity sensor is mounted in the collection chamber. The collection efficiency can be automatically corrected. The technique of exchanging the collection mylar reduces the waiting time and improves work efficiency. The apparatus is applied to the measurement of the radon concentration in the environment and the radon exhalation from the surface of the building materials, walls and ground. The lower detection limit is about 4Bq/m 3 for 222 Rn concentration and 5 x 10 -5 Bq/s/m 2 for 222 Rn exhalation rate

  20. The effect of time-dependent ventilation and radon (thoron) gas emanation rates in underground uranium mines

    International Nuclear Information System (INIS)

    Bigu, J.

    1987-01-01

    A theoretical radiation mine model, suitable for underground uranium mines, has been investigated. In this model, the rate of ventilation and/or the radon (thoron) gas emanation from mine walls are time-dependent. Several cases of practical interest have been investigated including sinusoidal, linear, exponential, stepwise, or a combination of two or more of the above. Analytical solutions were obtained for the time-dependent radon (thoron) gas emanation rate. However, because of the extreme analytical complexity of the solutions corresponding to the time-dependent ventilation rate case, numerical solutions were found using a special Runge-Kutta procedure and the Hamming's modified predictor-corrector method for the solution of linear initial-value problems. The mine model makes provisions for losses of radioactivity, other than by ventilation and radioactive decay, by, say, plate-out on mine walls, and by other mechanisms. Radioactivity data, i.e., radon, thoron, and their progeny, obtained with the above mine model for a number of ventilation and emanation conditions, are presented. Experimental data obtained in an inactive stope of an underground uranium mine for a time-dependent air flow case are shown. Air flow conditions (ventilation rate) were determined by tracer gas techniques using SF 6

  1. Removing method for radon gas exhausted from nuclear fuel material

    International Nuclear Information System (INIS)

    Kato, Kenji.

    1993-01-01

    A centrifugal separator is disposed in the midway of an exhaustion pipe of a nuclear fuel handling facility, and exhausted gases are sent into a rotational cylinder of the separator. Radon gases in the midway of exhaustion are separated from the exhaustion gases by the centrifugal force of the separator and caused to stagnate at the periphery of the circumferential wall of the rotational cylinder. At the same time, the exhaustion gases having the radon gases separated therefrom are exhausted from the periphery of a rotational shaft of the rotational cylinder. Then, the radon gases stagnated in the rotational cylinder are decayed depending on the half-decay time. With such procedures, the radon gases can be removed continuously without discharging them to the outside. Further, it is preferred that an exhaustion blower or the like for putting the inside of the nuclear fuel handing facility to a negative pressure is disposed as in a conventional case. Further, a plurality of centrifugal separators may be disposed to exhaustion pipes, to remove radon gases in the exhaust gases by a multi stage way. Radon gases can be removed in a saved space with no requirement for exchange of adsorbents or temperature control. (T.M.)

  2. Canadian population risk of radon induced lung cancer variation range assessment based on various radon risk models

    International Nuclear Information System (INIS)

    Chen, Jing

    2017-01-01

    To address public concerns regarding radon risk and variations in risk estimates based on various risk models available in the literature, lifetime lung cancer risks were calculated with five well-known risk models using more recent Canadian vital statistics (5-year averages from 2008 to 2012). Variations in population risk estimation among various models were assessed. The results showed that the Canadian population risk of radon induced lung cancer can vary from 5.0 to 17% for men and 5.1 to 18% for women based on different radon risk models. Averaged over the estimates from various risk models with better radon dosimetry, 13% of lung cancer deaths among Canadian males and 14% of lung cancer deaths among Canadian females were attributable to long-term indoor radon exposure. (authors)

  3. Monitoring of radon gas in caves of the Yorkshire Dales, United Kingdom

    International Nuclear Information System (INIS)

    Langridge, D; Stokes, R P; Jackson, C P

    2010-01-01

    A number of vocational training courses are held in caves in the Yorkshire Dales region of the United Kingdom. The instructors and students involved in these courses have the potential to be exposed to enhanced levels of radon ( 222 Rn) and its progeny as a result of their occupations. A prior radiological risk assessment for the training courses recommended that an environmental monitoring programme be carried out to establish the radon concentrations in the caves, and that the caving instructors wear personal radon dosemeters. Radon gas concentrations varied seasonally, being at their highest in summer and their lowest in winter. The lowest result was 40 Bq m -3 recorded in Lower Longchurn cave during winter, whilst the highest result was 4440 Bq m -3 recorded in Crackpot cave during the summer. As the individuals involved in the caving are entering atmospheres with radon gas concentrations in excess of 400 Bq m -3 , the Ionising Radiation Regulations 1999 (GB Parliament 2000 Ionising Radiations Regulations 1999 (London: Stationary Office) SI 1999/3232) apply. A system of work is therefore in place to control exposure to radon. This system of work stipulates an initial dose investigation level of 1 mSv, a second dose investigation level of 2 mSv and an annual dose limit of 6 mSv. The highest annual dose recorded to date is 2.2 mSv, although the average (median) annual dose is only 0.5 mSv.

  4. Assessing the effectiveness of slab flooring as a barrier to soil gas and radon infiltration

    International Nuclear Information System (INIS)

    Williamson, A.D.; Fowler, C.S.; McDonough, S.E.

    1995-01-01

    Experimental studies on the entry of soil gas and radon into slab-on-grade buildings have been carried out in instrumented, single-zone test structures. This work, as part of the Florida Radon Research Program, focused on the effectiveness of slab flooring variants as barriers to soil gas/radon entry. A second objective was the study of the role of subslab fill soil as both a potential source of and barrier to radon entry. Studies were made in well-sealed (∼ 600 mm 2 ELA) unoccupied test buildings placed on well-characterized, radium-bearing sandy fill soil. The buildings were instrumented with data acquisition systems to continuously monitor indoor radon concentrations, differential pressures at several subsurface locations, weather conditions, and soil moisture. The response of the structures to mechanical depressurization as well as natural driving forces was measured. Limited measurements were made regarding direct diffusive transport of radon through apparently intact concrete slabs, as well as transport through cracks in the floor structure

  5. Measurement Testing of Radon Gas for Fault Activity Detection in Rahtawu Muria, Pati

    International Nuclear Information System (INIS)

    Suntoko, Hadi; Hamzah, Imam

    2004-01-01

    The radon surface can be used to investigates not only for environment but also to be develop in an earth application. The investigation is carried out at the Rahtawu fault, that includes, to the Pati regency which is located 40 km South of ULA. The objective of study to measure the radon released from the fracture zone activities. RDA equipment is being used to measure the radon gas released. The result shown that the high value of radon is 311 cpm with the background of 18 cpm, whereas the low value falls at 0 cpm. The tattoo value are influenced by the soil condition, tattoo time, hardness, weather, soil/stone porosity and fault possession. (author)

  6. Preliminary results of soil radon gas survey of the Lake Bosomtwi impact crater

    International Nuclear Information System (INIS)

    Preko, S.; Danuor, S.K.; Menyeh, A.

    2004-01-01

    Soil radon gas survey was carried out in the Lake Bosomtwi impact crater area on eight profiles, which ran rapidly toward the end of the crater. One thousand soil samples, each weighing about 100g were acquired at a depth of 20 cm and at regular intervals of 10 m. The radon gas decay rate of the soil samples was then determined in the laboratory using the RDA-200 Radon detector and RDU-200 Degassing unit. It was found that generally areas south and east of the crater, which are severally sheared, faulted and fractured recorded high radon gas decay rates of the order of 800 counts/min whilst relatively undisturbed zones west of the crater recorded lower rates of the order of 20 counts/min. the cause of fracturing, shearing and faulting have been attributed to the effect of the meteorite impact in the Bosomtwi area, and therefore the results indicate that the soil radon gas survey could serve as a useful tool in mapping the impact-related structural characteristics of the crater. (author)

  7. Correlations of soil-gas and indoor radon with geology in glacially derived soils of the northern Great Plains

    International Nuclear Information System (INIS)

    Schumann, R.R.; Owen, D.E.; Peake, R.T.; Schmidt, K.M.

    1990-01-01

    This paper reports that a higher percentage of homes in parts of the northern Great Plains underlain by soils derived from continental glacial deposits have elevated indoor radon levels (greater than 4 pCi/L) than any other area in the country. Soil-gas radon concentrations, surface radioactivity, indoor radon levels, and soil characteristics were studied in areas underlain by glacially-derived soils in North Dakota and Minnesota to examine the factors responsible for these elevated levels. Clay-rich till soils in North Dakota have generally higher soil-gas radon levels, and correspondingly higher indoor radon levels, than the sandy till soils common to west-central Minnesota. Although the proportions of homes with indoor radon levels greater than 4 pCi/L are similar in both areas, relatively few homes underlain by sandy tills have screening indoor radon levels greater than 20 pCi/L, whereas a relatively large proportion of homes underlain by clayey tills have screening indoor radon levels exceeding 20 pCi/L. The higher radon levels in North Dakota are likely due to enhanced emanation from the smaller grains and to relatively higher soil radium concentrations in the clay-rich soils, whereas the generally higher permeability of the sandy till soils in Minnesota allows soil gas to be drawn into structures from a larger source volume, increasing indoor radon levels in these areas

  8. A simple bubbling system for measuring radon (222Rn) gas concentrations in water samples based on the high solubility of radon in olive oil.

    Science.gov (United States)

    Al-Azmi, D; Snopek, B; Sayed, A M; Domanski, T

    2004-01-01

    Based on the different levels of solubility of radon gas in organic solvents and water, a bubbling system has been developed to transfer radon gas, dissolving naturally in water samples, to an organic solvent, i.e. olive oil, which is known to be a good solvent of radon gas. The system features the application of a fixed volume of bubbling air by introducing a fixed volume of water into a flask mounted above the system, to displace an identical volume of air from an air cylinder. Thus a gravitational flow of water is provided without the need for pumping. Then, the flushing air (radon-enriched air) is directed through a vial containing olive oil, to achieve deposition of the radon gas by another bubbling process. Following this, the vial (containing olive oil) is measured by direct use of gamma ray spectrometry, without the need of any chemical or physical processing of the samples. Using a standard solution of 226Ra/222Rn, a lowest measurable concentration (LMC) of radon in water samples of 9.4 Bq L(-1) has been achieved (below the maximum contaminant level of 11 Bq L(-1)).

  9. Soil gas radon concentration across faults near Caracas, Venezuela

    International Nuclear Information System (INIS)

    Sajo-Bohus, L.; Flores, N.; Urbani, F.; Carreno, R.

    2001-01-01

    SSNTD were used across tectonic features of different degree of activity and lithology in four localities north of Caracas, Venezuela. The homemade dosimeters with LR115 film were buried 20-30 cm in the ground. This cheap and low- tech method proved very useful to understand the tectonic features involved, measuring higher Radon concentration above traces of active faults while in old and sealed faults the results only show the effect of the surrounding lithology. Radon concentration range is 4.3 - 27.2 kB/m 3 . (Author)

  10. A prediction model for assessing residential radon concentration in Switzerland

    International Nuclear Information System (INIS)

    Hauri, Dimitri D.; Huss, Anke; Zimmermann, Frank; Kuehni, Claudia E.; Röösli, Martin

    2012-01-01

    Indoor radon is regularly measured in Switzerland. However, a nationwide model to predict residential radon levels has not been developed. The aim of this study was to develop a prediction model to assess indoor radon concentrations in Switzerland. The model was based on 44,631 measurements from the nationwide Swiss radon database collected between 1994 and 2004. Of these, 80% randomly selected measurements were used for model development and the remaining 20% for an independent model validation. A multivariable log-linear regression model was fitted and relevant predictors selected according to evidence from the literature, the adjusted R², the Akaike's information criterion (AIC), and the Bayesian information criterion (BIC). The prediction model was evaluated by calculating Spearman rank correlation between measured and predicted values. Additionally, the predicted values were categorised into three categories (50th, 50th–90th and 90th percentile) and compared with measured categories using a weighted Kappa statistic. The most relevant predictors for indoor radon levels were tectonic units and year of construction of the building, followed by soil texture, degree of urbanisation, floor of the building where the measurement was taken and housing type (P-values <0.001 for all). Mean predicted radon values (geometric mean) were 66 Bq/m³ (interquartile range 40–111 Bq/m³) in the lowest exposure category, 126 Bq/m³ (69–215 Bq/m³) in the medium category, and 219 Bq/m³ (108–427 Bq/m³) in the highest category. Spearman correlation between predictions and measurements was 0.45 (95%-CI: 0.44; 0.46) for the development dataset and 0.44 (95%-CI: 0.42; 0.46) for the validation dataset. Kappa coefficients were 0.31 for the development and 0.30 for the validation dataset, respectively. The model explained 20% overall variability (adjusted R²). In conclusion, this residential radon prediction model, based on a large number of measurements, was demonstrated to be

  11. Gas exchange at the air-sea interface: a technique for radon measurements in seawater

    International Nuclear Information System (INIS)

    Queirazza, G.; Roveri, M.

    1991-01-01

    The rate of exchange of various gas species, such as O 2 , CO 2 etc. across the air-water interface can be evaluated from the 222 Rn vertical profiles in the water column. Radon profiles were measured in 4 stations in the NW Adriatic Sea, in September 1990, using solvent extraction and liquid scintillation counting techniques, directly on board the ship. The radiochemical procedure is described in detail. The lower limit of detection is approximately 0.4 mBq 1 -1 . The radon deficiency in the profiles gives estimates of the gas transfer rate across the air-sea interface ranging from 0.9 to 7.0 m d -1 . The suitability of the radon deficiency method in shallow water, enclosed seas is briefly discussed. (Author)

  12. Geographical information system for radon gas from soil measurement

    International Nuclear Information System (INIS)

    Orlando, P.; Amici, M.; Altieri, A.; Massari, P.; Miccadei, E.; Onofri, A.; Orlando, C.; Paolelli, C.; Paron, P.; Perticaroli, P.; Piacentini, T.; Silvestri, C.; Minach, L.; Verdi, L.; Bertolo, A.; Trotti, F.

    2000-03-01

    The working program foresees the realization of an geographical information system for the check in field of the geological parameters and determination of uranium and radium contents in various type of rocks. It is here also pointed out a measuring method for radon concentration in soil [it

  13. Parametric modelling of temporal variations in radon concentrations in homes

    International Nuclear Information System (INIS)

    Revzan, K.L.; Turk, B.H.; Harrison, J.; Nero, A.V.; Sextro, R.G.

    1988-01-01

    The 222 Rn concentrations in the living area, the basement, and the undelying soil of a New Jersey home have been measured at half-hour intervals over the course of a year, as have indoor and outdoor temperatures, wind speed and direction, and indoor-outdoor and basement-subslab pressures; in addition, periods of furnace opration have been logged. We generalize and extend an existing radon entry model in order to demonstrate the dependence of the radon concentration on the environmental variales and the extent of furnace use. The model contains parameters which are dependent on geological and structural factors which have not been measured or otherwise determined; statistical methods are used to find the best values of the parameters. The non-linear regression of the model predictions (over time) on the measured living area radon concentrations yields an R/aup 2/ of 0.88. 9 refs., 2 figs

  14. Identification of advective entry of soil-gas radon into a crawl space covered with sheets of polyethylene foil

    International Nuclear Information System (INIS)

    Andersen, C.; Koopmanns, M.; Meijer, R.J. de

    1996-04-01

    To assess the effectiveness of mitigative measures against radon ( 222 Rn) entry into houses, experiments were conducted in a crawl-space house where the dirt floor of the crawl space was covered with sheets of 0.23 mm polyethylene foil fixed to the walls. The radon concentration was measured below the foil and in the crawl space together with environmental variables such as indoor-outdoor pressure differences. The experimental data was analyzed using various types of models including a simplistic mass-balance model, a regression model, and a two-dimensional numerical model based on Darcy flow or soil gas and combined diffusive and advective transport of radon. The main outcome of the work was that: (i) The soil-gas entry rate per pascal depressurization was at the order of 1 m 3 h -1 , (ii) the stack-related part of the depressurization of the crawl space (approx. 0.1 Pa deg. C -1 ) was controlled by the temperature difference between the living room of the house and the outdoors (not by the difference between the crawl space and the outdoors), (iii) that part of the wind-related depressurization that was measured by the pressure transducers seemed to force radon into the crawl space in the same proportion as the stack-related part of the depressurization, (iv) the ratio of advective and diffusive entry was approx. 0.7, when the crawl space was depressurized 1.5 Pa, (v) the effective diffusivity of the foil was found to be three orders of magnitude larger than that measured in the laboratory (the enhanced diffusivity was most likely caused by leaks in the foil and by mixing fans located in the crawl space), and (vi) there was no measurable mitigative impact of having the sheets of foil on the crawl-space floor even if the crawl space was artificially pressurized or depressurized. (au) 28 tabs., 36 ills., 61 refs

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

    International Nuclear Information System (INIS)

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

    1991-01-01

    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

  16. Soil-gas radon/helium surveys in some neotectonic areas of NW Himalayan foothills, India

    Directory of Open Access Journals (Sweden)

    S. Mahajan

    2010-06-01

    Full Text Available The present research is aimed at accessing the relationship between variation in the soil gases radon (222Rn and helium (4He and recently developed fissures and other neotectonic features in Nurpur and Nadha areas of the NW Himalayas, India. Two soil-gas surveys were conducted on/near known faults to reconfirm their position using soil gas technique and to check their present activity. During these surveys, soil-gas samples were collected along traverses crossing the observed structures. The data analysis reveals that the concentrations of radon and helium along the Dehar lineament and the longitudinal profile (Profile D are very high compared to any other thrust/lineament of the Nurpur area. The Nadha area shows high values of radon and helium concentrations along/near the Himalayan Frontal Fault (HFF as compared to the adjoining areas. This indicates the presence of some buried fault/fault zone running parallel to the HFF, not exposed to the surface and not delineated by satellite data but is geochemically active and might be tectonically active too. Hence, soil helium and radon gas patterns have been combined with morphological and geological observations to supply useful constraints for deformation of tectonic environments.

  17. Comparative measurements of soil gas radon concentration using thermoluminescent and track detectors

    Czech Academy of Sciences Publication Activity Database

    Turek, Karel; Gelev, M.; Dimov, I.

    2004-01-01

    Roč. 38, spec. iss. (2004), s. 843-846 ISSN 1350-4487 Institutional research plan: CEZ:AV0Z1048901 Keywords : soil gas * radon concentration * thermoluminescent detectors Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.664, year: 2004

  18. Soil-Gas Radon Anomaly Map of an Unknown Fault Zone Area, Chiang Mai, Northern Thailand

    Science.gov (United States)

    Udphuay, S.; Kaweewong, C.; Imurai, W.; Pondthai, P.

    2015-12-01

    Soil-gas radon concentration anomaly map was constructed to help detect an unknown subsurface fault location in San Sai District, Chiang Mai Province, Northern Thailand where a 5.1-magnitude earthquake took place in December 2006. It was suspected that this earthquake may have been associated with an unrecognized active fault in the area. In this study, soil-gas samples were collected from eighty-four measuring stations covering an area of approximately 50 km2. Radon in soil-gas samples was quantified using Scintrex Radon Detector, RDA-200. The samplings were conducted twice: during December 2014-January 2015 and March 2015-April 2015. The soil-gas radon map obtained from this study reveals linear NNW-SSE trend of high concentration. This anomaly corresponds to the direction of the prospective fault system interpreted from satellite images. The findings from this study support the existence of this unknown fault system. However a more detailed investigation should be conducted in order to confirm its geometry, orientation and lateral extent.

  19. Is environmental radon gas associated with the incidence of neurodegenerative conditions? A retrospective study of multiple sclerosis in radon affected areas in England and Wales

    International Nuclear Information System (INIS)

    Groves-Kirkby, Christopher J.; Denman, Antony R.; Campbell, Jackie; Crockett, Robin G.M.; Phillips, Paul S.; Rogers, Stephen

    2016-01-01

    To test whether an association exists between radon gas concentration in the home and increased multiple sclerosis (MS) incidence, a retrospective study was undertaken of MS incidence in known areas of raised domestic radon concentration in England and Wales, using The Health Improvement Network (THIN) clinical research database. The study population comprised 20,140,498 person-years of clinical monitoring (males: 10,056,628: 49.93%; females: 10,083,870: 50.07%), representing a mean annual population of 2.5 million individuals. To allow for the possible latency of MS initiation following exposure, data extraction was limited to patients with at least five years registration history with the same GP practice before first diagnosis. Patient records were allocated to one of nine radon concentration bands depending on the average radon level in their postcode sector. MS incidence was analysed by searching for patients with first MS diagnosis over the eight calendar years 2005–2012 inclusive. 1512 new MS cases were diagnosed, 1070 females, 442 males, equivalent to raw incidence rates of 7.51, 10.61 and 4.40 per 10 5 person-years respectively, comparable to previously reported results. Of these new cases, 115 could be allocated to one of the radon bands representing high radon areas. Standardising to the UK 2010 population, excess relative risk (ERR) figures for MS were calculated for each radon band. Linear regression of ERR against mean band radon concentration shows a positive gradient of 0.22 per 100 Bq·m −3 (R 2  = 0.25, p = 0.0961) when forced through the origin to represent a linear-no-threshold response. The null hypothesis falls inside the 95% confidence interval for the linear fit and therefore this fit is not statistically significant. We conclude that, despite THIN sampling around 5% of the population, insufficient data was available to confirm or refute the hypothesised association between MS incidence and radon concentration. - Highlights:

  20. Radon soil-gas concentration and exhalation from mine tailings dams in South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Ongori, J.; Lindsay, R. [University of the Western Cape, Department of Physics, Private Bag X17, Bellville 7535 (South Africa); Newman, R. [Stellenbosch University, Department of Physics, Private Bag X1 Matieland 7602 (South Africa); Maleka, P. [iThemba LABS, Department of Nuclear Physics, P. O. Box 722, Somerset West 7129 (South Africa)

    2014-07-01

    In Africa as well as in the world, South Africa plays an important role in the mining industry which dates back almost 120 years. Mining activities in South Africa mainly take place in Gauteng Province. Every year million of tons of rocks are taken from underground, milled and processed to extract gold. The uranium bearing tailings are disposed in dumpsites. These tailings dumps contain considerable amounts of radium ({sup 226}Ra) and have therefore been identified as large sources of radon ({sup 222}Rn). Radon is a noble gas formed by the decay of radium which in turn is derived from the radioactive decay of uranium ({sup 238}U). Radon release from these tailings dumps pose health concerns for the surrounding communities. Radon soil gas concentrations and exhalations from a non-operational mine dump (Kloof) which belongs to Carletonville Gold Field, Witwatersrand, South Africa have been investigated. The continuous radon monitor, the Durridge RAD7 was used to measure {sup 222}Rn soil gas concentration in the tailings dump at five different spots. The radon soil gas concentration levels were measured at depths starting from 30 cm below ground/air interface up to 110 cm at intervals of 20 cm. The concentrations recorded ranged from 26±1 to 472±23 kBq.m{sup -3}. Furthermore, thirty four soil samples were taken from the spots where radon soil gas measurements were measured for laboratory-based measurement using the low background Hyper Pure Germanium (HPGe) gamma-ray detector available at the Environmental Radioactivity Laboratory (ERL), iThemba LABS, Western Cape Province. The soil samples were collected in the depth range 0-30 cm. After analysis the weighted average activity concentrations in the soils samples were 308±7 Bq.kg{sup -1}, 255±5 Bq.kg{sup -1} and 18±1 Bq.kg{sup -1} for {sup 238}U, {sup 40}K and {sup 232}Th, respectively. A number of factors such as the radium activity concentration and its distribution in soil grains, soil grain size, soil porosity

  1. PO.RA project. An analysis on gas radon concentrations in soil versus fluctuations in the groundwater table

    International Nuclear Information System (INIS)

    Serentha', C.; Torretta, M.

    2001-01-01

    Man is daily exposed to natural radiation, mainly due to cosmic rays and natural radioactive elements, whose most important radioactive daughters are 222 Rn (radon) and 220 Rn (thoron). Being these ones gaseous, they can spread through the ground, reaching the atmosphere and accumulating in rooms, where their concentrations may be very high. As radon exhalation is strongly connected with the hydrogeological features of the environment, this study tried to find a relationship between fluctuations in the groundwater table and gas radon concentrations in soil, in order to try estimates of indoor radon concentrations [it

  2. RADON CONCENTRATION TIME SERIES MODELING AND APPLICATION DISCUSSION.

    Science.gov (United States)

    Stránský, V; Thinová, L

    2017-11-01

    In the year 2010 a continual radon measurement was established at Mladeč Caves in the Czech Republic using a continual radon monitor RADIM3A. In order to model radon time series in the years 2010-15, the Box-Jenkins Methodology, often used in econometrics, was applied. Because of the behavior of radon concentrations (RCs), a seasonal integrated, autoregressive moving averages model with exogenous variables (SARIMAX) has been chosen to model the measured time series. This model uses the time series seasonality, previously acquired values and delayed atmospheric parameters, to forecast RC. The developed model for RC time series is called regARIMA(5,1,3). Model residuals could be retrospectively compared with seismic evidence of local or global earthquakes, which occurred during the RCs measurement. This technique enables us to asses if continuously measured RC could serve an earthquake precursor. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Correlation between indoor radon and soil gas availability: Results of field studies

    International Nuclear Information System (INIS)

    Kothari, B.K.; Kunz, C.; Lilley, W.

    1990-01-01

    To correlate indoor radon concentrations with soil gas, the authors have carried out a field survey of surficial material in selected regions of New York State. The survey consisted of measurements of gamma radiation, Ra-226, Rn-222 and the permeability for gas flow in surficial material. Based on the data, three areas with a potential for above average indoor radon concentrations have been identified: (1) a black shale region in Onondaga County; (2) a granitic region in Orange County; and (3) a black shale region in Erie County. For an area with potential for below-average indoor radon concentrations, sandy deposits on Long Island with an average concentration of 0.7 pCi Ra-226/g and 160 pCi Rn-222/L at 2-feet depth, have been selected. Fifteen homes from each of these four areas are under test for indoor radon. Measurements of air infiltration rates and soil gas availability parameters are planned for all 60 homes

  4. Rn3D: A finite element code for simulating gas flow and radon transport in variably saturated, nonisothermal porous media

    International Nuclear Information System (INIS)

    Holford, D.J.

    1994-01-01

    This document is a user's manual for the Rn3D finite element code. Rn3D was developed to simulate gas flow and radon transport in variably saturated, nonisothermal porous media. The Rn3D model is applicable to a wide range of problems involving radon transport in soil because it can simulate either steady-state or transient flow and transport in one-, two- or three-dimensions (including radially symmetric two-dimensional problems). The porous materials may be heterogeneous and anisotropic. This manual describes all pertinent mathematics related to the governing, boundary, and constitutive equations of the model, as well as the development of the finite element equations used in the code. Instructions are given for constructing Rn3D input files and executing the code, as well as a description of all output files generated by the code. Five verification problems are given that test various aspects of code operation, complete with example input files, FORTRAN programs for the respective analytical solutions, and plots of model results. An example simulation is presented to illustrate the type of problem Rn3D is designed to solve. Finally, instructions are given on how to convert Rn3D to simulate systems other than radon, air, and water

  5. Measurement and apportionment of radon source terms for modeling indoor environments

    International Nuclear Information System (INIS)

    Harley, N.H.

    1990-01-01

    This research has two main goals; (1) to quantify mechanisms for radon entry into homes of different types and to determine the fraction of indoor radon attributable to each source and (2) to model and calculate the dose (and therefore alpha particle fluence) to cells in the human and animal tracheobronchial tree that is pertinent to induction of bronchogenic carcinoma from inhaled radon daughters

  6. Modelling and experimental study of the behavior of radon and radon decay products in an enclosure. Application to houses

    International Nuclear Information System (INIS)

    Gouronnec, A.M.

    1995-01-01

    Since the eighties, more and more studies were performed about radon and its decay products in houses with one of the aim being the estimation of the dose received by their inhabitants. Then, the principal objective of this work is to describe the behaviour of radon and its decay products within a dwelling. In the first part to the report, a few definitions are given and data from literature give an idea of indoor radon and radon decay products activities and/or size distribution. Aspects of dosimetry are presented too. In the second part of the work, a mathematical model, called 'PRADDO' of Physic of Radon and radon Decay products in Domestic environment is developed on the basis of the classical model written by Jacobi in 1972. On the one hand, it has to predict radon decay products activities in systems consisting in one or more enclosure(s), from radon activity and from ambient aerosol concentration and size distribution. On the other hand, one part of the model is assigned to study the influence of the entry model parameters variation on the calculated quantities. Then, in the third part of the work, two experimental studies are realised in order to compare measurements to modelization. The first experimentation is a laboratory work, made on the test bench ICARE from IPSN, and the second one consists in describing the basement of an occupied house from Brittany. In the two cases, the comparison between experiments and modelling shows a good agreement if particles are present in the air, but any conclusion is made when is no aerosol in the enclosure. (author). 158 refs., 81 figs., 42 tabs

  7. Experience of gas purification and radon control in BOREXINO

    Science.gov (United States)

    Zuzel, G.

    2018-01-01

    The BOREXINO detector, located in the Gran Sasso National Laboratory in Italy, has been designed for real-time spectroscopy of low energy solar neutrinos. Extremely low background rates required to successfully accomplish this goal triggered a very extensive R&D program focused on developments of novel background reduction and assay techniques. This has been achieved and, in many cases, these techniques are still the most sensitive world-wide. Extremely low background of the BOREXINO detector made it possible to probe almost entire spectrum of the solar neutrinos in real-time. Radon, as one of the main background sources, needed special considerations and developments, described briefly in this paper.

  8. Design and Realization of a Radon Gas Calibration System

    International Nuclear Information System (INIS)

    Boussek, Amal

    2013-01-01

    Our project consists on the automatization of a Radon calibration room. The first step was the development of several electronic cards collecting outside data coming to our device (pressure and temperature). Using ISIS software, we have designed these electronic cards: pressure, temperature, power supply, PIC interface and control card. In the second part, we have programmed the PIC 16F877 using the PCW compiler to display data on an LCD screen and sent them through the RS232 serial to the hyper-terminal and to control the motor and the fan. The last part aims to develop an interface using LabVIEW to command our device.

  9. Hierarchical modeling of indoor radon concentration: how much do geology and building factors matter?

    Science.gov (United States)

    Borgoni, Riccardo; De Francesco, Davide; De Bartolo, Daniela; Tzavidis, Nikos

    2014-12-01

    Radon is a natural gas known to be the main contributor to natural background radiation exposure and only second to smoking as major leading cause of lung cancer. The main concern is in indoor environments where the gas tends to accumulate and can reach high concentrations. The primary contributor of this gas into the building is from the soil although architectonic characteristics, such as building materials, can largely affect concentration values. Understanding the factors affecting the concentration in dwellings and workplaces is important both in prevention, when the construction of a new building is being planned, and in mitigation when the amount of Radon detected inside a building is too high. In this paper we investigate how several factors, such as geologic typologies of the soil and a range of building characteristics, impact on indoor concentration focusing, in particular, on how concentration changes as a function of the floor level. Adopting a mixed effects model to account for the hierarchical nature of the data, we also quantify the extent to which such measurable factors manage to explain the variability of indoor radon concentration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Detecting buried radium contamination using soil-gas and surface-flux radon meaurements

    International Nuclear Information System (INIS)

    Karp, K.E.

    1988-06-01

    The Technical Measurements Center (TMC) has investigated the effectiveness of using radon soil-gas under surface-flux measurments to locate radium contamination that is buried sufficiently deep to be undetectable by surface gamma methods. At the first test site studied, an indication of a buried source was revealed by mapping anomalous surface-flux and soil-gas concentrations in the near surface overburden. The mapped radon anomalies were found to correspond in rough outline to the shape of the areal extent of the deposit as determined by borehole gamma-ray logs. The 5.9pCi/g radium deposit, buried 2 feet below the surface, went undetected by conventional surface gamma measurements. Similar results were obtained at the second test site where radon and conventional surface gamma measurements were taken in an area having radium concentrations ranging from 13.3 to 341.0 pCi/g at a depth of 4 feet below the surface. The radon methods were found to have a detection limit for buried radium lower than that of the surface gamma methods, as evidenced by the discovery of the 13.3 pCi/g deposit which went undetected by the surface gamma methods. 15 refs., 33 figs., 8 tabs

  11. Mathematical model of radon activity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Paschuk, Sergei A.; Correa, Janine N.; Kappke, Jaqueline; Zambianchi, Pedro, E-mail: sergei@utfpr.edu.br, E-mail: janine_nicolosi@hotmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Denyak, Valeriy, E-mail: denyak@gmail.com [Instituto de Pesquisa Pele Pequeno Principe, Curitiba, PR (Brazil)

    2015-07-01

    Present work describes a mathematical model that quantifies the time dependent amount of {sup 222}Rn and {sup 220}Rn altogether and their activities within an ionization chamber as, for example, AlphaGUARD, which is used to measure activity concentration of Rn in soil gas. The differential equations take into account tree main processes, namely: the injection of Rn into the cavity of detector by the air pump including the effect of the traveling time Rn takes to reach the chamber; Rn release by the air exiting the chamber; and radioactive decay of Rn within the chamber. Developed code quantifies the activity of {sup 222}Rn and {sup 220}Rn isotopes separately. Following the standard methodology to measure Rn activity in soil gas, the air pump usually is turned off over a period of time in order to avoid the influx of Rn into the chamber. Since {sup 220}Rn has a short half-life time, approximately 56s, the model shows that after 7 minutes the activity concentration of this isotope is null. Consequently, the measured activity refers to {sup 222}Rn, only. Furthermore, the model also addresses the activity of {sup 220}Rn and {sup 222}Rn progeny, which being metals represent potential risk of ionization chamber contamination that could increase the background of further measurements. Some preliminary comparison of experimental data and theoretical calculations is presented. Obtained transient and steady-state solutions could be used for planning of Rn in soil gas measurements as well as for accuracy assessment of obtained results together with efficiency evaluation of chosen measurements procedure. (author)

  12. Toward resolving model-measurement discrepancies of radon entry into houses

    International Nuclear Information System (INIS)

    Garbesi, K.; Lawrence Berkeley Lab., CA

    1994-10-01

    Analysis of the literature indicated that radon transport models significantly and consistently underpredict the advective entry into houses of soil-gas borne radon. Advective entry is the dominant mechanism resulting in high concentrations of radon indoors. The author investigated the source of the model-measurement discrepancy via carefully controlled field experiments conducted at an experimental basement located in natural soil in Ben Lomond, California. Early experiments at the structure confirmed the existence and magnitude of the model-measurement discrepancy, ensuring that it was not merely an artifact of inherently complex and poorly understood field sites. The measured soil-gas entry rate during structure depressurization was found to be an order of magnitude larger than predicted by a current three-dimensional numerical model of radon transport. The exact magnitude of the discrepancy depends on whether the arithmetic or geometric mean of the small-scale measurements of permeability is used to estimate the effective permeability of the soil. This factor is a critical empirical input to the model and was determined for the Ben Lomond site in the typical fashion using single-probe static depressurization measurements at multiple locations. The remainder of the dissertation research tests a hypothesis to explain the observed discrepancy: that soil permeability assessed using relatively small-scale probe measurements does not reflect bulk soil permeability for flows that is likely to occur at larger scales of several meters or more in real houses and in the test structure. The idea is that soil heterogeneity is of a nature that, as flows occur over larger scales, larger scales of heterogeneity are encountered that facilitate larger flux rates, resulting in a scale dependence of effective soil permeability

  13. Simulation of radon short lived decay daughters' inhalation using the lung compartmental model

    International Nuclear Information System (INIS)

    Tomulescu, Vlad C.

    2002-01-01

    Radon and its short-lived decay daughters are the main source of radiation on natural ways for population. The radon gas, released from soil, water or construction materials is producing by radioactive decay the following solid daughters: Po-218, Bi-214, Pb-214, and Po-214, which can attach to aerosols, and consequently penetrate the organism by inhalation. The human respiratory tract can be approximated by aid of a compartment model that takes into account the different anatomical structures exposed to contamination and irradiation, as well as the respective physiological processes. This model is associated to a mathematical equation system that describes the behavior of the radioactive material inside the body. The results represent the dose equivalent on different organs and tissues, as a function of subject and the activity performed in contaminating environment. (author)

  14. Analytical and numerical models for estimating the effect of exhaust ventilation on radon entry in houses with basements or crawl spaces

    International Nuclear Information System (INIS)

    Mowris, R.J.

    1986-08-01

    Mechanical exhaust ventilation systems are being installed in newer, energy-efficient houses and their operation can increase the indoor-outdoor pressure differences that drive soil gas and thus radon entry. This thesis presents simplified models for estimating the pressure driven flow of radon into houses with basements or crawl spaces, due to underpressures induced by indoor-outdoor temperature differences, wind, or exhaust ventilation. A two-dimensional finite difference model is presented and used to calculate the pressure field and soil gas flow rate into a basement situated in soil of uniform permeability. A simplified analytical model is compared to the finite difference model with generally very good agreement. Another simplified model is presented for houses with a crawl space. Literature on radon research is also reviewed to show why pressure driven flow of soil gas is considered to be the major source of radon entry in houses with higher-than-average indoor radon concentrations. Comparisons of measured vs. calculated indoor radon concentrations for a house with a basement showed the simplified basement model underpredicting on average by 25%. For a house with a crawl space the simplified crawl space model overpredicted by 23% when the crawl space vents are open and 48% when the crawl space vents are sealed

  15. Preliminary Monitoring of Soil gas Radon in Potentially Active Faults, San Sai District, Chiang Mai Province, Thailand

    Science.gov (United States)

    Pondthai, P.; Udphuay, S.

    2013-05-01

    The magnitude of 5.1 Mw earthquake occurred in San Sai District, Chiang Mai Province, Thailand in December 2006 was considered an uncommon event due to the fact that there was no statistical record of such significant earthquake in the area. Therefore the earthquake might have been associated with a potentially active fault zone within the area. The objective of this study is to measure soil gas radon across this unknown fault zone within the Chiang Mai Basin, northern Thailand. Two profiles traversing the expected fault zone of soil gas radon measurements have been monitored, using TASTRAK solid state track nuclear detectors (SSNTDs). Radon signals from three periods of measurement show a distinctive consistent spatial distribution pattern. Anomalous radon areas along the profiles are connected to fault locations previously interpreted from other geophysical survey results. The increased radon signal changes from the radon background level with the signal-to-background ratio above 3 are considered anomalous. Such pattern of radon anomaly supports the existence of the faults. The radon measurement, therefore is a powerful technique in mapping active fault zone.

  16. Airborne geophysical radon hazard mapping

    International Nuclear Information System (INIS)

    Walker, P.

    1993-01-01

    Shales containing uranium pose a radon health hazard even when covered by several meters of overburden. Such an alum shale in southern Norway has been mapped with a joint helicopter borne electromagnetic (HEM) and radiometric survey. Results are compared with ground spectrometer, radon emanometer and radon gas measurements in dwellings, and a model to predict radon gas concentrations from the airborne data is developed. Since the shale is conductive, combining the HEM data with the radiometric channel allows the shale to be mapped with greater reliability than if the radiometric channel were used alone. Radiometrically more active areas which do not pose a radon gas hazard can thus be separated from the shales which do. The ground follow-up work consisted of spectrometer and radon emanometer measurements over a uranium anomaly coinciding with a conductor. The correlation between the airborne uranium channel, the ground uranium channel and emanometry is extremely good, indicating that airborne geophysics can, in this case, be used to predict areas having a high radon potential. Contingency tables comparing both radon exhalation and concentration in dwellings with the airborne uranium data show a strong relationship exists between exhalation and the airborne data and while a relationship between concentration and the airborne data is present, but weaker

  17. Evaluation of genetic alteration induced by radon gas using the micronucleus test (Tradescantia sp. clone KU-20)

    International Nuclear Information System (INIS)

    Bruschi, Armando L.; Azevedo, Heliana de; Macacini, Jose F.; Roque, Claudio V.

    2011-01-01

    The first observations over the existence of radon gas (Rn), initially known as 'thorium emanation', were carried out between the end of 19 th and beginning of 20 th centuries. A result of uranium-238 (U 238 ) radioactive decay, radon is a tasteless, odorless and colorless gas under room temperature, with a 3.825-day half life and particle α emission in its decay, and as final product of its disintegration, the stable lead-206 isotope (Pb 206 ). Being it is the gas with the highest density known, closed and poor ventilated environments are favorable to its accumulation, with its inhalation being the highest health risk. The use of vegetal bioindicators has shown to be excellent on the monitoring of air quality and on mutagenic potential of various pollutants contained in the atmosphere. Within this context, the objective of this study was to evaluate the micronucleus test application potential utilizing the Tradescantia sp. clone KU-20, in order to evaluate genetic alterations induced by radon gas. Stems of Tradescantia sp. clone KU-20, previously immerse in Hoagland solution, were introduced in a radon detection equipment's calibration chamber (Alphaguard), containing radium salt. Afterwards, the accommodated stems were exposed to radon gas (the average radon concentration was 7.639 KBq/m3) for 24 hours. The results demonstrated an increase on micronucleus formation (39.23 + 2.143 MCN/100 tetrads) in stems exposed in relation to the negative control (18.00 + 1.396 MCN/100 tetrads). The difference between the values indicated a significant increase on micronucleus frequency in the inflorescences subjected to radon gas. The presented results demonstrated the micronucleus test application potential using Tradescantia clone KU-20 to evaluate genetic effects induced by radon gas. (author)

  18. Radon baseline monitoring around a potential shale gas development site in Yorkshire, England

    International Nuclear Information System (INIS)

    Daraktchieva, Z.; Wasikiewicz, J. M.; Howarth, C. B.; Bradley, E.J.

    2017-01-01

    The Vale of Pickering in Yorkshire, England has been identified as a potential area for shale gas extraction. Public Health England joined a collaboration led by the British Geological Survey for environmental baseline monitoring near the potential shale gas extraction site following a grant award from UK Government Department for Business, Energy and Industrial Strategy. The analysis of results for the first 6 months of indoor monitoring indicated that the results followed a log-normal distribution. The numbers of homes found to be at or above the Action Level followed the numbers predicted by the radon potential maps. The results from the measurements of outdoor air in this study indicated that the radon concentrations are slightly higher than previously measured but close to the detection limit of the technique. (authors)

  19. RADON BASELINE MONITORING AROUND A POTENTIAL SHALE GAS DEVELOPMENT SITE IN YORKSHIRE, ENGLAND.

    Science.gov (United States)

    Daraktchieva, Z; Wasikiewicz, J M; Howarth, C B; Bradley, E J

    2017-11-01

    The Vale of Pickering in Yorkshire, England has been identified as a potential area for shale gas extraction. Public Health England joined a collaboration led by the British Geological Survey for environmental baseline monitoring near the potential shale gas extraction site following a grant award from UK Government Department for Business, Energy and Industrial Strategy. The analysis of results for the first 6 months of indoor monitoring indicated that the results followed a log-normal distribution. The numbers of homes found to be at or above the Action Level followed the numbers predicted by the radon potential maps. The results from the measurements of outdoor air in this study indicated that the radon concentrations are slightly higher than previously measured but close to the detection limit of the technique. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Experimental procedures for the calibration of scintillation cells used in the determination of radon gas concentrations

    International Nuclear Information System (INIS)

    Grenier, M; Bigu, J.

    1982-02-01

    Experimental and analytical procedures are described for the calibration of scintillation cells used for the determination of radon gas concentration. In-house designed and built scintillation cells, used routinely in the monitoring of radon gas in uranium mine underground environments and in the laboratory, were calibrated. The cells had a volume of approximately 158 cm 3 and an α-counting efficiency ranging from 50% to 64%. Calibration factors for the cells were determined. Values ranged approximately from 0.177 cpm/pCiL -1 (4.77 cpm/BqL -1 ) to 0.224 cpm/pCiL -1 (6.05 cpm/BqL -1 ). The calibration facilities at the Elliot Lake Laboratory are briefly described

  1. Short-term temporal variations of soil gas radon concentration and comparison of measurement techniques

    Czech Academy of Sciences Publication Activity Database

    Neznal, M.; Matolín, M.; Just, G.; Turek, Karel

    2004-01-01

    Roč. 108, č. 1 (2004), s. 55-63 ISSN 0144-8420 R&D Projects: GA AV ČR KSK2067107; GA AV ČR KSK4055109 Grant - others:Projekt SÚJB(CZ) R/2/2000 Institutional research plan: CEZ:AV0Z1048901 Keywords : radon * soil gas * temporal variations Subject RIV: DL - Nuclear Waste, Radioactive Pollution ; Quality Impact factor: 0.617, year: 2003

  2. The radon

    International Nuclear Information System (INIS)

    1998-01-01

    This booklet is intended to answer briefly the most important questions about the nature and sources of radon, its pathways from environment to organism, as well as the ways to minimize its concentration in the habitat's atmosphere. The radon is a naturally appearing radioactive gas, produced through the decay of uranium and radium present in the terrestrial crust. It can be found everywhere on the planet's surface and it is emitted particularly from the granite and volcanic underground rocks as well as from certain construction materials. It is one of the agents producing pulmonary cancer, although not so dangerous as the tobacco is. The following items are elaborated in this booklet: - the place of radon in the average exposure to ionizing radiations of the French population; - the risk; - the radon in the environment (the meteorological conditions, the nature of the rocks); - radon in dwellings (radon measurements in the French dwellings, the entrance pathways of radon, the dependence of radon concentration on the profession and way of life of the inhabitants); - radon measurements; - how to reduce the radon concentration in dwellings

  3. Radon as a natural tracer for gas transport within uranium waste rock piles

    International Nuclear Information System (INIS)

    Silva, N.C.; Chagas, E.G.L.; Dias, D.C.S.; Guerreiro, E.T.Z.; Alberti, H.L.C.; Braz, M.L.; Abreu, C.B.; Lopez, D.; Branco, O.; Fleming, P.

    2014-01-01

    Acid mine drainage (AMD) has been identified as the main cause for outflow of acid water and radioactive/non-radioactive contaminants. AMD encompasses pyrites oxidation when water and oxygen are available. AMD was identified in uranium waste rock piles (WRPs) of Industrias Nucleares do Brasil-Caldas facility (Brazilian uranium mine), resulting in high costs for water treatment. AMD reduction is the main challenge, and scientific investigation has been conducted to understand oxygen and water transportation within WRPs, where 222 Rn is used as natural tracer for oxygen transportation. The study consists of soil radon gas mapping in the top layer of WRP4 using active soil gas pumping, radon adsorption in active charcoal and 222 Rn determination using high-resolution gamma-ray spectrometry. A sampling network of 71 points was built where samples were collected at a depth of 40 cm. Soil radon gas concentration ranged from 33.7 to 1484.2 kBq m -3 with mean concentration of 320.7±263.3 kBq m -3 . (authors)

  4. Integrated source-risk model for radon: A definition study

    International Nuclear Information System (INIS)

    Laheij, G.M.H.; Aldenkamp, F.J.; Stoop, P.

    1993-10-01

    The purpose of a source-risk model is to support policy making on radon mitigation by comparing effects of various policy options and to enable optimization of counter measures applied to different parts of the source-risk chain. There are several advantages developing and using a source-risk model: risk calculations are standardized; the effects of measures applied to different parts of the source-risk chain can be better compared because interactions are included; and sensitivity analyses can be used to determine the most important parameters within the total source-risk chain. After an inventory of processes and sources to be included in the source-risk chain, the models presently available in the Netherlands are investigated. The models were screened for completeness, validation and operational status. The investigation made clear that, by choosing for each part of the source-risk chain the most convenient model, a source-risk chain model for radon may be realized. However, the calculation of dose out of the radon concentrations and the status of the validation of most models should be improved. Calculations with the proposed source-risk model will give estimations with a large uncertainty at the moment. For further development of the source-risk model an interaction between the source-risk model and experimental research is recommended. Organisational forms of the source-risk model are discussed. A source-risk model in which only simple models are included is also recommended. The other models are operated and administrated by the model owners. The model owners execute their models for a combination of input parameters. The output of the models is stored in a database which will be used for calculations with the source-risk model. 5 figs., 15 tabs., 7 appendices, 14 refs

  5. Method for filtering radon from a gas system

    International Nuclear Information System (INIS)

    Sowinski, R.F.

    1992-01-01

    This patent describes a method of filtering, adjacent to an end user-customer's residence, or business in which at least a single gas appliance is located, a natural gas stream in which benz-a-anthracene has been concentrated at sufficient levels to be a health threat in a natural gas gathering and distributing network. It comprises introducing the natural gas stream to a filter selected from a group that includes impingement, passing the filtered natural gas stream to the customer's gas appliance wherein safe use of the energy associated with the stream occurs, periodically and safely removing the filter for disposing of captured benz-a-anthracene, inserting a new filter in place of the removed filter of step

  6. Radon gas inside historical buildings in the city of Cordoba

    International Nuclear Information System (INIS)

    Perez, R.; Germanier, A.; Rubio, M.; Sbarato, D.; Zappino, R.

    1998-01-01

    Full text: In this work measurements of the Radon ( 222 Rn) concentration in the inside of historical buildings which date back to the end of the 17th and the beginning of the 18th Centuries have been carried out in the city of Cordoba (Argentina). Meteorological factors such as room temperature and atmospheric pressure have not shown to affect, to a great extent, the results obtained. By comparing the concentration of 222 Rn in environments at different levels we inferred that the soil underlying the buildings does not represent an important source of 222 Rn. The main occurrence of the element was found in room walls, which shows that local building materials are an important source of 222 Rn. Among the materials used in these buildings are granitic rocks, and to a lesser extent, lime, sand and marble. The 222 Rn concentrations recorded in some of the rooms surveyed reach values which are close to the minimum intervene level set by international standards in 4pCi/l. The study of the effects of ventilation in the concentration of 222 Rn allows us to conclude that its values decrease to accepted levels by means of a natural and efficient ventilation of the rooms. (author) [es

  7. PO.RA project. An analysis on gas radon concentrations in soil versus fluctuations in the groundwater table; Progetto PO.RA.. Analisi della concentrazione di gas radon nel non saturo in relazione alla soggiacenza della falda freatica

    Energy Technology Data Exchange (ETDEWEB)

    Serentha' , C.; Torretta, M. [Agenzia Regionale per la Protezione dell' Ambiente della Lombardia, Dipartimento di Monza, Monza (Italy)

    2001-09-01

    Man is daily exposed to natural radiation, mainly due to cosmic rays and natural radioactive elements, whose most important radioactive daughters are {sup 222}Rn (radon) and {sup 220}Rn (thoron). Being these ones gaseous, they can spread through the ground, reaching the atmosphere and accumulating in rooms, where their concentrations may be very high. As radon exhalation is strongly connected with the hydrogeological features of the environment, this study tried to find a relationship between fluctuations in the groundwater table and gas radon concentrations in soil, in order to try estimates of indoor radon concentrations. [Italian] L'uomo e' quotidianamente esposto ad una radioattivita' di origine naturale, dovuta principalmente ai raggi cosmici ed alla presenza di alcuni elementi radioattivi naturali, i cui discendenti radioattivi piu' importanti sono il {sup 222}Rn (radon) e il {sup 220}Rn (thoron). Tali elementi, a causa della loro natura gassosa, si possono diffondere attraverso il terreno e raggiungere l'atmosfera sovrastante; cio' puo' provocarne l'accumulo in ambienti chiusi, dando luogo a concentrazioni anche elevate con possibili conseguenze sulla salute. Poiche' l'esalazione del gas radon e' foremente legata alle caratteristiche idrogeologiche dell'ambiente, in questo lavoro si e' cercato di definire una relazione che legasse le variazioni della soggiacenza della falda freatica alle variazioni della concentrazione del gas radon nel non saturo, al fine di verificare se sia possibile effettuare un'attivita' previsionale applicabile ai rilievi di gas radon indoor.

  8. Levels of radon gas concentration and progeny in homes of Potosi City, Bolivia to 4000 m

    International Nuclear Information System (INIS)

    Mamani M, R.; Claros J, J.; Vasquez A, R.

    2015-10-01

    Full text: In this work the presence of radon gas was determined, which is a radioactive contaminant that comes from underground, able to penetrate the houses. The danger is that when mixed air and when inhaled can cause serious damage to the lungs, for the short life time that has radon and progeny for decay, damaging the pulmonary alveoli and reducing breathing capacity of the habitants, then causing polycythemia in some cases. The study was carried out in homes in the city of Potosi, Bolivia located at 4000 m. The quantification of radon gas and progeny was performed with the equipment Alpha-Zaeller-2 (Az-2), quantification was realized in 6 zones of the city of Potosi, chosen randomly. In each zone were carried out measurements in 40 homes (2 rooms more permanent), both day and night, for a period of 3 days in two different seasons and with concentrations of average humidity of 20, 50 and 80%. The values obtained for each period vary depending on the season and 30 to 50% of the allowable values given by the EPA and Who for housing. (Author)

  9. Identification of advective entry of soil-gas radon into a crawl space covered with sheets of polyethylene foil

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, C. [Risoe National Lab., Dept. of Nucl. Safety Res. and Nucl. Facilities, Roskilde (Denmark); Koopmanns, M.; Meijer, R.J. de [Kernfysische Versneller Inst., Environmental Radioactivity Res., Groningen (Netherlands)

    1996-04-01

    To assess the effectiveness of mitigative measures against radon ({sup 222}Rn) entry into houses, experiments were conducted in a crawl-space house where the dirt floor of the crawl space was covered with sheets of 0.23 mm polyethylene foil fixed to the walls. The radon concentration was measured below the foil and in the crawl space together with environmental variables such as indoor-outdoor pressure differences. The experimental data was analyzed using various types of models including a simplistic mass-balance model, a regression model, and a two-dimensional numerical model based on Darcy flow or soil gas and combined diffusive and advective transport of radon. The main outcome of the work was that: (i) The soil-gas entry rate per pascal depressurization was at the order of 1 m{sup 3} h{sup -1}, (ii) the stack-related part of the depressurization of the crawl space (approx. 0.1 Pa deg. C{sup -1}) was controlled by the temperature difference between the living room of the house and the outdoors (not by the difference between the crawl space and the outdoors), (iii) that part of the wind-related depressurization that was measured by the pressure transducers seemed to force radon into the crawl space in the same proportion as the stack-related part of the depressurization, (iv) the ratio of advective and diffusive entry was approx. 0.7, when the crawl space was depressurized 1.5 Pa, (v) the effective diffusivity of the foil was found to be three orders of magnitude larger than that measured in the laboratory (the enhanced diffusivity was most likely caused by leaks in the foil and by mixing fans located in the crawl space), and (vi) there was no measurable mitigative impact of having the sheets of foil on the crawl-space floor even if the crawl space was artificially pressurized or depressurized. (au) 28 tabs., 36 ills., 61 refs.

  10. Indoor radon

    International Nuclear Information System (INIS)

    1997-12-01

    The radon, a natural radioactive gas, is present almost everywhere on the earth's surface. It can be accumulated at high concentration in confined spaces (buildings, mines, etc). In the last decades many studies conducted in several countries showed that inhaling important amounts of radon rises the risk of lung cancer. Although, the radon is a naturally appearing radioactive source, it may be the subject of a human 'enhancement' of concentration. The increasing radon concentration in professional housing constitutes an example of enhanced natural radioactivity which can induce health risks on workers and public. Besides, the radon is present in the dwelling houses (the domestic radon). On 13 May 1996, the European Union Council issued the new EURATOM Instruction that establishes the basic standards of health protection of population and workers against the ionizing radiation hazards (Instruction 96/29/EURATOM, JOCE L-159 of 29 June 1996). This instruction does not apply to domestic radon but it is taken into consideration by another EURATOM document: the recommendation of the Commission 90/143/EURATOM of 21 February 1990 (JOCE L-80 of 27 March 1990). The present paper aims at establishing in accordance to European Union provisions the guidelines for radon risk management in working places, as well as in dwelling houses, where the implied risk is taken into account. This document does not deal with cases of high radon concentration on sites where fabrication, handling or storage of radium sources take place. These situations must be treated by special studies

  11. Modeling dynamic behavior of Radon-222 in the planetary boundary layer

    International Nuclear Information System (INIS)

    Yuan, Y.C.; Stunder, M.J.

    1983-01-01

    A model has been used to simulate the dynamic behavior of radon concentration in the lower atmosphere from naturally occurring sources. The model includes prediction of radon exhalation rate from the surface of the ground due to convection and diffusion processes and the radon concentration profile in the planetary boundary layer. A time-dependent radon exhalation rate, variable mixing height, and altitude-dependent diffusivity are incorporated into the diffusion model by transforming the governing equation. The Galerkin finite-element technique and Crank-Nicholson finite different time marching are used in solving the discretized differential equations. The model-simulated time-varying radon concentrations near the ground agree well with measurements made over a period of seven days. It has been demonstrated that the model provides a reasonably good prediction of ambient radon concentration. As a general tool, with the input of actual radon concentration measurements, the model is also capable of estimating average radon exhalation rate from the ground surface. With current techniques, radon flux measurement is still a time-consuming and difficult task

  12. Modeling the potential impacts of different radon policies for the U.S. housing stock

    International Nuclear Information System (INIS)

    Peterson, M.D.; Ritchie, I.M.

    1995-01-01

    According to the Environmental Protection Agency (EPA) and other public health agencies in the United States, radon may be the leading cause (along with passive smoking) of lung cancer deaths among nonsmokers. Radon is estimated to be the second leading cause of lung cancer death in smokers behind smoking-related lung cancer. EPA estimates that 7,000 to 30,000 lung cancer deaths each year are due to radon exposure. (It is implied that radon-related lung cancer deaths can be prevented by reducing radon levels below EPA's guideline levels). Current EPA radon policy is based on a strategy of education, the transfer of testing and remediation technologies to the public and private sectors, and recently proposed radon-resistant construction standards for new homes. This paper models the effectiveness of current proposed, and alternative policies for reducing radon risks in U.S. residential construction. The results of our analysis suggest that EPS's projections of 2,200 'lives saved annually' as a result of its current action level of 4 pCi/l will not be achieved with its current policy in the near future. Overall, the response of radon-related mortality to most policy options is delayed and flat due in part to the large number of houses with low radon levels and the long latency period between radon exposure and the development of cancer. The modeling results suggest that more aggressive smoking reduction programs may yield greater benefits in overall lung cancer mortality (but not reduced radon exposure) than most radon-related policies. (au)

  13. Regional and Detailed Survey for Radon Activities in Soil-Gas and Groundwater in the Okchon Zone, Korea

    Science.gov (United States)

    Je, H.-K.; Chon, H.-T.

    2012-04-01

    The Okchon zone in Korea provides a typical example of natural geological materials enriched in potentially toxic elements including uranium which is parent nuclide for radon gas. For the purpose of radon radioactivity risk assessment, making the map of radon risk grade from Okchon zone, regional and detailed field surveys were carried out during 3 years. The study area is located in the central part of Korea, called the Okchon zone (about 5,100 km2), which occur in a 80km wide, northeast-trending belt that extends across the Korean Peninsula. The Okchon zone is underlain by metasedimentary rocks of unknown age that are composed mainly of black slate, phyllite, shale, and limestone. The three research areas (defined as Boeun, Chungju, and Nonsan) for detailed survey were selected from the results of regional survey. Results of detailed radon survey indicated a wide range of radon activities for soil-gases (148-1,843 pCi/L) and ground waters (23-5,540 pCi/L). About 15 percent of soil-gas samples exceeded 1,000 pCi/L and 84 percent of ground water samples exceeded the MCL (maximum contaminant level) of drinking water, 300 pCi/L, which proposed by U.S. Environmental Protection Agency in 1999. For detailed survey, radon activities of soil-gas and ground water were classified as bedrock geology, based on 1/50,000 geological map and field research. For soil-gas measurements, mean values of radon activity from black slate-shale (789 pCi/L) were highest among the other base rocks. And for groundwater measurements, mean value of radon activities were decreased in the order of granite (1,345 pCi/L) > black shale-slate (915 pCi/L) > metasediments (617 pCi/L). Result of indoor radon measurement from detailed survey areas showed that about 50% of houses exceeded the indoor guideline, 4 pCi/L. For the radon risk assessment in indoor environment showed that probability of lung cancer risk from the houses located on the granite base rock (3.0×10-2) was highest among the other

  14. The design and realization of calibration apparatus for measuring the concentration of radon in three models

    Energy Technology Data Exchange (ETDEWEB)

    Huiping, Guo [The Second Artillery Engineering College, Xi' an (China)

    2007-06-15

    For satisfying calibration request of radon measure in the laboratory, the calibration apparatus for radon activity measure is designed and realized. The calibration apparatus can auto-control and auto-measure in three models. sequent mode, pulse mode and constant mode. The stability and reliability of the calibration apparatus was tested under the three models. The experimental result shows that the apparatus can provides an adjustable and steady radon activity concentration environment for the research of radon and its progeny and for the calibration of its measure. (authors)

  15. Correlations between radon in soil gas and the activity of seismogenic faults in the Tangshan area, North China

    International Nuclear Information System (INIS)

    Wang, Xin; Li, Ying; Du, Jianguo; Zhou, Xiaocheng

    2014-01-01

    The spatial variation of soil gas radon values were correlated with the seismogenic faults and earthquakes in the Tangshan area (north China). Radon concentrations were measured at 756 sites in an area about 2500 km 2 from April to May 2010. The background and anomaly threshold values calculated were 4730.4 Bq/m 3 and 8294.1 Bq/m 3 , respectively. Radon concentrations highlight a decreasing gradient from NE to SW in the area. Higher values mostly distributed in the NE sector of the Tangshan fault and the Luanxian fault where the Tangshan (Ms 7.8), and Luanxian (MS 7.1) earthquakes occurred in 1976 and 17 earthquakes with MS = 3.0 occurred in this area since 2005. Radon values illustrated a close relation with the shallow fault trace and earthquake activity in the area. The active fault zones and the associated fractures formed by the larger earthquakes, act as paths for radon migration. - Highlights: • Radon concentrations at 756 sites were attained in the Tangshan area. • The background value and anomaly threshold of Rn were calculated out. • Radon concentration decreasing from NE to SW in the study area. • Rn value has a close relation with the fault and earthquake activity

  16. Analysis of problems and failures in the measurement of soil-gas radon concentration.

    Science.gov (United States)

    Neznal, Martin; Neznal, Matěj

    2014-07-01

    Long-term experience in the field of soil-gas radon concentration measurements allows to describe and explain the most frequent causes of failures, which can appear in practice when various types of measurement methods and soil-gas sampling techniques are used. The concept of minimal sampling depth, which depends on the volume of the soil-gas sample and on the soil properties, is shown in detail. Consideration of minimal sampling depth at the time of measurement planning allows to avoid the most common mistakes. The ways how to identify influencing parameters, how to avoid a dilution of soil-gas samples by the atmospheric air, as well as how to recognise inappropriate sampling methods are discussed. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Measurement and apportionment of radon source terms for modeling indoor environments

    International Nuclear Information System (INIS)

    Harley, N.H.

    1992-01-01

    This research has two main goals; (1) to quantify mechanisms for radon entry into homes of different types and to determine the fraction of indoor radon attributable to each source and (2) to model and calculate the dose (and therefore alpha particle fluence) to cells in the human and animal tracheobronchial tree that is pertinent to induction of bronchogenic carcinoma from inhaled radon daughters. The dosimetry has been extended to include organs other than the lung

  18. Episodic radon changes in subsurface soil gas along active faults and possible relation to earthquakes

    International Nuclear Information System (INIS)

    King, C.

    1980-01-01

    Subsurface soil gas along active faults in central California has been continuously monitored by the Track Etch method to test whether its radon-isotope content may show any premonitory changes useful for earthquake prediction. The monitoring network was installed in May 1975 and has since been gradually expanded to consist of more than 60 stations along a 380-km section of the San Andreas fault system between Santa Rosa and Cholame. This network has recorded several episodes, each lasting several weeks to several months, during which the radon concentration increased by a factor of approximately 2 above average along some long, but limited, fault segments (approx.100 km). These episodes occurred in different seasons and do not appear to be systematically related to changes in meteorological conditions. However, they coincided reasonably well in time and space with larger local earthquakes above a threshold magnitude of about 4.0. These episodic radon changes may be caused by a changing outgassing rate in the fault zones in response to some episodic strain changes, which incidentally caused the earthquakes

  19. Measurements on, and modelling of diffusive and advective radon transport in soil

    DEFF Research Database (Denmark)

    Graff, E.R. van der; Witteman, G.A.A.; Spoel, W.H. van der

    1994-01-01

    Results are presented of measurements on radon transport in soil under controlled conditions with a laboratory facility consisting of a stainless steel vessel (height and diameter 2 m) filled with a uniform column of sand. At several depths under the sand surface, probes are radially inserted...... into the vessel to measure the radon concentration in the soil gas. To study advective radon transport a perforated circular box is placed in the sand close to the bottom of the vessel. By pressurising this box, an air flow through the sand column is induced. Radon concentration profiles were measured without...... an air flow as a function of time, and for several values of the air flow, equilibrium radon concentration profiles were measured....

  20. Radon reduction

    International Nuclear Information System (INIS)

    Hamilton, M.A.

    1990-01-01

    During a radon gas screening program, elevated levels of radon gas were detected in homes on Mackinac Island, Mich. Six homes on foundations with crawl spaces were selected for a research project aimed at reducing radon gas concentrations, which ranged from 12.9 to 82.3 pCi/l. Using isolation and ventilation techniques, and variations thereof, radon concentrations were reduced to less than 1 pCi/l. This paper reports that these reductions were achieved using 3.5 mil cross laminated or 10 mil high density polyethylene plastic as a barrier without sealing to the foundation or support piers, solid and/or perforated plastic pipe and mechanical fans. Wind turbines were found to be ineffective at reducing concentrations to acceptable levels. Homeowners themselves installed all materials

  1. Assessment of potential radiological population health effects from radon in liquefied petroleum gas

    Energy Technology Data Exchange (ETDEWEB)

    Gesell, Thomas F; Johnson, Jr, Raymond H; Bernhardt, David E

    1977-02-01

    Liquefied petroleum gas (LPG) contains varying amounts of radon-222 which becomes dispersed within homes when LPG is used in unvented appliances. Radon-222 decays to alpha-emitting daughter products which are associated with increased lung cancer when inhaled and deposited in the respiratory system. The average dose equivalents to the bronchial epithelium from the use of LPG in unvented kitchen ranges and space heaters are estimated to be about 0.9 and 4.0 mrem/year, respectively. When extrapolated to the United States population at risk, the estimated tracheobronchial dose equivalents are about 20,000 and 10,000 person-rems/year for these appliances, or a total of about 30,000 person-rems/year. These doses are very small compared to other natural and man-made sources of ionizing radiation. It is estimated that these low doses would result in less than one lung cancer a year for the total U.S. population. Consequently, the use of LPG containing radon-222 does not contribute significantly to the incidence of lung cancer in the United States. Furthermore, the cost for control of radon levels in LPG would be over $50 million for reduction of one health effect, therefore it is concluded that a requirement for such controls would not be cost effective on a national basis. This study did indicate that individual dose equivalents could possibly exceed 500 mrem/year. However, existing data are not sufficient to determine the significance of such potentially high individual doses. (author)

  2. Moisture dependence of radon transport in concrete : Measurements and modeling

    NARCIS (Netherlands)

    Cozmuta, [No Value; van der Graaf, ER; de Meijer, RJ

    2003-01-01

    The moisture dependence of the radon-release rate of concrete was measured under well controlled conditions. It was found that the radon-release rate almost linearly increases up to moisture contents of 50 to 60%. At 70 to 80% a maximum was found and for higher moisture contents the radon-release

  3. Dissolved radon and uranium in groundwater in a potential coal seam gas development region (Richmond River Catchment, Australia).

    Science.gov (United States)

    Atkins, Marnie L; Santos, Isaac R; Perkins, Anita; Maher, Damien T

    2016-04-01

    The extraction of unconventional gas resources such as shale and coal seam gas (CSG) is rapidly expanding globally and often prevents the opportunity for comprehensive baseline groundwater investigations prior to drilling. Unconventional gas extraction often targets geological layers with high naturally occurring radioactive materials (NORM) and extraction practices may possibly mobilise radionuclides into regional and local drinking water resources. Here, we establish baseline groundwater radon and uranium levels in shallow aquifers overlying a potential CSG target formation in the Richmond River Catchment, Australia. A total of 91 groundwater samples from six different geological units showed highly variable radon activities (0.14-20.33 Bq/L) and uranium levels (0.001-2.77 μg/L) which were well below the Australian Drinking Water Guideline values (radon; 100 Bq/L and uranium; 17 μg/L). Therefore, from a radon and uranium perspective, the regional groundwater does not pose health risks to consumers. Uranium could not explain the distribution of radon in groundwater. Relatively high radon activities (7.88 ± 0.83 Bq/L) in the fractured Lismore Basalt aquifer coincided with very low uranium concentrations (0.04 ± 0.02 μg/L). In the Quaternary Sediments aquifers, a positive correlation between U and HCO3(-) (r(2) = 0.49, p uranium was present as uranyl-carbonate complexes. Since NORM are often enriched in target geological formations containing unconventional gas, establishing radon and uranium concentrations in overlying aquifers comprises an important component of baseline groundwater investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Radon and health

    International Nuclear Information System (INIS)

    Chobanova, Nina

    2016-01-01

    Radon is radioactive noble gas that can be found in soil, water, outdoor and indoor air. Since environmental radon on average accounts for about half of all human exposure to radiation from natural sources, increasing attention has been paid to exposure to radon and its associated health risks. Many countries have introduced regulations to protect their population from radon in dwellings and workplaces. In this article are discussed main characteristics of radon, including sources of exposure, variation in radon exposure, how managing risks from radon exposure, how to measure the concentration of radon. There are results of measurements conducted under the 'National radon programme' in Bulgaria also. Key words: radon, sources of exposure, risk, cancer, measure to decrease the concentration [bg

  5. Radon in soil gas: distributions and correlations with the lithologies and pedologies of RMBH - Metropolitan region of Belo Horizonte - Minas Gerais - Brazil

    International Nuclear Information System (INIS)

    Lara, Evelise G.; Santos, Talita de O.; Oliveira, Arno Heeren de

    2013-01-01

    The concentration of radon in the soil gas is an important indicator to predict the radon geologic potential, usually indicated by Geological Radon Potential - GEORP, which is defined as the percent number of dwellings with indoor air radon concentration above the U.S.EPA action limit. The objective of this work was to investigate the distribution of radon concentration in soil gas and its relation with the pedologies and lithologies in the RMBH. The radon concentrations in soil gas were determined by using an AlphaGUARD monitor at 150 measurement points over the lithologies and pedologies of the area. The concentrations 226 Ra were determined by gamma spectrometry (HPGe) and U and Th by ICP-MS. The permeabilities of the soil were determined by using the RADON-JOK permeameter. Regarding pedologies, the perferric Red Latosols had the highest concentrations, with arithmetic mean to 60.6 ± 8.7 kBq.m -3 . Regarding lithologies, areas where the bedrocks are predominantly schists and metagraywackes showed the highest radon concentrations, with arithmetic mean to 46.5 ± 9.9 kBq.m -3 . The areas of lithology or pedology, in which the average radon concentrations are the highest also exhibit higher GEORP, e.g. for the perferric Red Latosol pedology shows GEORP of 26,5%. In this pedology, over 50% of the measurement points shows radon concentrations above of 50.0 kBq.m -3 , that, by the 'Swedish Criteria' classifies the area as high radon risk. The correlation with GEORP is even more significant when the radon concentration in soil gas is combined with soil permeability, through the Soil Radon Index indicator. (author)

  6. Radon in soil gas: distributions and correlations with the lithologies and pedologies of RMBH - Metropolitan region of Belo Horizonte - Minas Gerais - Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Lara, Evelise G.; Santos, Talita de O.; Oliveira, Arno Heeren de, E-mail: evelise.lara@gmail.com, E-mail: talitaolsantos@yahoo.com.br, E-mail: heeren@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, M.G (Brazil). Dept. de Engenharia Nuclear; Rocha, Zildete; Palmieri, Helena E. Leonhardt; Brito, Walter de; Araujo, Gabriela Bastos D. de, E-mail: rochaz@cdtn.br, E-mail: help@cdtn.br, E-mail: britow@cdtn.br, E-mail: gabibastosdias@hotmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    The concentration of radon in the soil gas is an important indicator to predict the radon geologic potential, usually indicated by Geological Radon Potential - GEORP, which is defined as the percent number of dwellings with indoor air radon concentration above the U.S.EPA action limit. The objective of this work was to investigate the distribution of radon concentration in soil gas and its relation with the pedologies and lithologies in the RMBH. The radon concentrations in soil gas were determined by using an AlphaGUARD monitor at 150 measurement points over the lithologies and pedologies of the area. The concentrations {sup 226}Ra were determined by gamma spectrometry (HPGe) and U and Th by ICP-MS. The permeabilities of the soil were determined by using the RADON-JOK permeameter. Regarding pedologies, the perferric Red Latosols had the highest concentrations, with arithmetic mean to 60.6 ± 8.7 kBq.m{sup -3}. Regarding lithologies, areas where the bedrocks are predominantly schists and metagraywackes showed the highest radon concentrations, with arithmetic mean to 46.5 ± 9.9 kBq.m{sup -3}. The areas of lithology or pedology, in which the average radon concentrations are the highest also exhibit higher GEORP, e.g. for the perferric Red Latosol pedology shows GEORP of 26,5%. In this pedology, over 50% of the measurement points shows radon concentrations above of 50.0 kBq.m{sup -3}, that, by the 'Swedish Criteria' classifies the area as high radon risk. The correlation with GEORP is even more significant when the radon concentration in soil gas is combined with soil permeability, through the Soil Radon Index indicator. (author)

  7. Error in measuring radon in soil gas by means of passive detectors

    International Nuclear Information System (INIS)

    Tanner, A.B.

    1991-01-01

    Passive detection of radon isotopes depends on diffusion of radon atoms from the sites of their generation to the location of the detecting or collecting device. Because some radon decays en route to a passive detector in soil, the radon concentration measured by the detector must be less than the concentration in those soil pores where it is undiminished by diffusion to the detector cavity. The true radon concentration may be significantly underestimated in moist soils. (author)

  8. LIFETIME LUNG CANCER RISKS ASSOCIATED WITH INDOOR RADON EXPOSURE BASED ON VARIOUS RADON RISK MODELS FOR CANADIAN POPULATION.

    Science.gov (United States)

    Chen, Jing

    2017-04-01

    This study calculates and compares the lifetime lung cancer risks associated with indoor radon exposure based on well-known risk models in the literature; two risk models are from joint studies among miners and the other three models were developed from pooling studies on residential radon exposure from China, Europe and North America respectively. The aim of this article is to make clear that the various models are mathematical descriptions of epidemiologically observed real risks in different environmental settings. The risk from exposure to indoor radon is real and it is normal that variations could exist among different risk models even when they were applied to the same dataset. The results show that lifetime risk estimates vary significantly between the various risk models considered here: the model based on the European residential data provides the lowest risk estimates, while models based on the European miners and Chinese residential pooling with complete dosimetry give the highest values. The lifetime risk estimates based on the EPA/BEIR-VI model lie within this range and agree reasonably well with the averages of risk estimates from the five risk models considered in this study. © Crown copyright 2016.

  9. The Reference Laboratory for Radon Gas Activity Concentration Measurements at PSI; Das Referenzlabor fuer Radongas-Konzentrationsmessungen am PSI

    Energy Technology Data Exchange (ETDEWEB)

    Schuler, Christoph

    1998-09-01

    Active or passive radon gas measuring instruments are exposed during intercomparison exercises in the radon chamber of the Reference Laboratory for Radon Gas Concentration Measurements at Paul Scherrer Institut: The traceability of radon gas measurements to nationally and internationally acknowledged standards is inspected in the reference atmosphere of the chamber with calibrated {sup 222}Rn activity concentration. The use of secondary standards guarantees the traceability of the radon chamber reference atmosphere. Besides the principal secondary standard, a radon gas standard (secondary standard I), a {sup 226}Ra standard solution (secondary standard II) and a {sup 222}Rn emanation standard (secondary standard III) are used. The {sup 222}Rn activity delivered by one of these standards is quantitatively transferred into a reference volume and hence converted to an activity concentration serving for the calibration of a measuring instrument transfer standard consisting of scintillation cell and counter. By this way, the transfer standard calibration is related and traceable to the internationally acknowledged primary standard laboratories National Institute of Standards and Technology, Gaithersburg, Maryland (U.S.A.) or National Physical Laboratory, Teddington, Middlesex (UK). The calibrated transfer standard is then used to calibrate the radon gas activity concentration in the radon chamber. For a single grab sampling determination of the {sup 222}Rn activity concentration in the radon chamber with the transfer standard, the estimation of Type A and Type B uncertainties yields a relative expanded uncertainty (95% confidence level) of minimum 3% for high concentration levels (10 kBqm{sup -3}) and maximum 30% for low concentration levels (0.2 kBqm{sup -3}). Extended evaluations of the reproducibility of calibration factor measurements obtained by calibration of the transfer standard with the secondary standards I, II and III show a very good reproducibility quality

  10. The radon gas. An air pollutant El gas radón como contaminante atmosférico

    Directory of Open Access Journals (Sweden)

    José Luis Arteche

    2010-12-01

    Full Text Available In this work different aspects about the problem of the radon in dwellings are approached. This gas of natural origin is virtually present in all the soils in the earth’s crust due to the presence of uranium and radium in the composition of them. Depending on architectural factors and of occupancy habits of the house, high concentrations of this gas can be reached indoors. In these situations, there is a quantifiable increment of the risk of developing lung cancer in the inhabitants of the housing. In the last years the methodological improvements in the realization of epidemiologic studies have led to the obtaining of scientific evidences about the relationship between the presence of indoor radon and the risk of lung cancer. This relationship, found years ago in workers of uranium mines, has been corroborated in the case of the residential radon by the light of several recent meta-analysis performed on groups of epidemiologic studies. More than 6.000 radon measurements have been carried out in Spain during the last 25 years. A summary of the results obtained from the main national radon surveys are also presented, as well as the criteria recently established by the Spanish Nuclear Safety Council concerning radon action levels in dwellings and workplaces.En este trabajo se abordan distintos aspectos acerca de la problemática del radón en viviendas. Este gas de origen natural se encuentra prácticamente en la totalidad de los suelos de la corteza terrestre debido a la presencia de uranio y radio en la composición de los mismos. En función de factores arquitectónicos y de hábitos de ocupación de la vivienda pueden alcanzarse concentraciones elevadas del gas en interiores. En estas situaciones existe un incremento cuantificable del riesgo de desarrollar cáncer de pulmón en los habitantes de la vivienda. En los últimos años, las mejoras metodológicas en la realización de estudios epidemiológicos han conducido a la obtención de

  11. Bio-mathematical models for radon daughters inhalation. The ModeLung software

    International Nuclear Information System (INIS)

    Tomulescu, Vlad C.; Rusu, Mircea

    2002-01-01

    Radon and its decay daughters are the most important sources for natural irradiation of population. ModeLung software is based on the human respiratory tract compartment model and is computing radiation doses on several internal organs and tissues for subjects inhaling radon daughters attached to aerosols. Radiation doses are presented for several subjects performing different types of activity under specific environmental conditions. (authors)

  12. Radon problems

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1985-01-01

    This chapter examines the health hazards resulting from the release of naturally occurring radioactive gas derived from the decay of uranium. It is estimated that random inhalation is now causing about 10,000 fatal lung cancers per year in the US. Radon is constantly being generated in rocks and soils (in which uranium is naturally present) and in materials produced from them (e.g., brick, stone, cement, plaster). It is emphasized that radon levels in buildings are typically 5 times higher than outdoors because radon diffusing up from the ground below or out of bricks, stone, cement, or plaster is trapped inside for a relatively long time

  13. Correlation of 210Po implanted in glass with radon gas exposure: sensitivity analysis of critical parameters using a Monte-Carlo approach.

    Science.gov (United States)

    Walsh, C; McLaughlin, J P

    2001-05-14

    In recent years, 210Po implanted in glass artefacts has been used as an indicator of the mean radon gas concentration in dwellings in the past. Glass artefacts have been selected in many dwellings and the alpha-recoil implanted 210Po concentration has been measured using various techniques. Some of these retrospective techniques use a model to estimate the retrospective radon gas on the basis of this surface 210Po activity. The accumulation of 210Po on glass surfaces is determined by the deposition regime over the exposure period. The 210Po activity is determined not only by the radon progeny deposition velocities, but by other room parameters such as ventilation rate, aerosol conditions and the surface to volume ratio of the room. Up to now in using room models, a nominal or 'base-case' scenario is used, i.e. a single value is chosen for each input parameter. In this paper a Monte-Carlo analysis is presented in which a probability distribution for each parameter is chosen, based on measurements quoted in the literature. A 210Po surface activity is calculated using a single value drawn from each of the parameter distributions using a pseudo-random number generator. This process is repeated n times (up to 20,000), producing n independent scenarios with corresponding 210Po values. This process permits a sensitivity analysis to be carried out to see the effect of changes in inputs on the model output.

  14. Calculation Of Radon Gas Inhaled By A Front End Worker Of The Nuclear Fuel Cycles

    International Nuclear Information System (INIS)

    Soedardjo

    1996-01-01

    The calculation of Radon gas inhaled by workers in a front end nuclear fuel cycle has been studied. The cycle of front end nuclear fuel is underground uranium exploration on Remaja tunnel West Kalimantan. The activities of mining consider of drilling, blasting, transporting mineral and tunnel supporting were chosen, It is assumed that in one month, for a worker has four assignments namely in tunnel I, tunnel II, tunnel III and tunnel IV, The activities in the mine are divided into some categories, namely 12 hours of drilling, 2 hours of after blasting, 9 hours of mineral transportation and 8 hours of tunnel support construction. The result of calculation shows that the average Radon gas concentration on each particular location is still less than maximum permissible concentration 300 pCi/l. The prediction of maximum dose inhaled by one uranium miner during a year is 2.3 x 10 2 μCi which is less than BATAN regulation 7.3 x 10 2 μCi

  15. Dynamical Model for Indoor Radon Concentration Monitoring

    Czech Academy of Sciences Publication Activity Database

    Brabec, Marek; Jílek, K.

    2009-01-01

    Roč. 20, č. 6 (2009), s. 718-729 ISSN 1180-4009. [TIES 2007. Annual Meeting of the International Environmental Society /18./. Mikulov, 16.08.2007-20.08.2007] Institutional research plan: CEZ:AV0Z10300504 Keywords : non-parametric regression * dynamic modeling * time-varying coefficients Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 1.000, year: 2009

  16. The role of ventilation in controlling the dispersion of radon gas from a cellar in a domestic house

    International Nuclear Information System (INIS)

    Ward, I.C.; Wang, F.; Sharples, S.; Pitts, A.C.

    1994-01-01

    In certain parts of the United Kingdom where radon gas seeps from the ground into the basement of domestic housing, normal methods of removing this gas by using under floor extract ventilation is not appropriate. In this situation the radon gas enters the basement through the side walls of the cellar and hence into the house. Using mechanical ventilation to either pressurise or de-pressurise the cellar may be an appropriate solution to this problem, however, before installing such a system in a house a ventilation strategy must be established. This paper sets out a ventilation strategy for minimising the ingress of radon into a domestic house, which has been established by simulating the air movement within a domestic house using Breeze Version 6 for a range of environmental conditions. The results of this analysis show that in winter when the emission of radon gas is most strong de-pressurisation of the basement can improve the ingress of the gas to the rest of the house. (author)

  17. Modeling radon flux from the earth's surface

    International Nuclear Information System (INIS)

    Schery, S.D.; Wasiolek, M.A.

    1998-01-01

    We report development of a 222 Rn flux density model and its use to estimate the 222 Rn flux density over the earth's land surface. The resulting maps are generated on a grid spacing of 1 0 x 1 0 using as input global data for soil radium, soil moisture, and surface temperature. While only a first approximation, the maps suggest a significant regional variation (a factor of three is not uncommon) and a significant seasonal variation (a factor of two is not uncommon) in 222 Rn flux density over the earth's surface. The estimated average global flux density from ice-free land is 34 ± 9 mBq m -2 s -1 . (author)

  18. Public perceptions of radon risk

    International Nuclear Information System (INIS)

    Mainous, A.G. III; Hagen, M.D.

    1993-01-01

    Since 1984, a significant amount of media attention has focused on health threats from radon gas exposure. Using a probability telephone survey of adults (n = 685), we studied public perceptions of risk from radon exposure versus other environmental health risks. The results indicated that 92% of those individuals who had heard of radon believe radon to be a health risk, although only 4% believe they are currently exposed to high levels of radon gas. Perception of risk from radon was positively related to other perceptions of environmental risks. Younger and less educated individuals were more likely to perceive radon as a health risk. Women were three-and-one-half times as likely as men to perceive risk from radon. However, there was no significant relationship between perceived risk from radon and cigarette smoking. Media attention has apparently led to public awareness of radon hazards, but further attention is needed to improve smokers' awareness of their special risks from radon

  19. Correlation between radon gas emanation and porosity in ornamental stones; Correlacao entre emanacao de gas radonio e porosidade de rochas ornamentais do Estado do Ceara, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Leiliane Rufina Pereira de; Artur, Antonio Carlos; Bonotto, Daniel Marcos, E-mail: leili_ane@hotmail.com, E-mail: acartur@rc.unesp.br, E-mail: dbonotto@rc.unesp.br [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil); Nogueira Neto, Jose de Araujo, E-mail: nogueira@ufc.br [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Geologia

    2014-01-15

    This article makes correlations between levels of gas {sup 222}Rn emanation and corresponding porosity for thirteen samples of granitic rocks ornamental state of Ceara. For both determinations of physical indexes (bulk density, apparent porosity and water absorption, the levels of U, monitoring emanation of radon gas are made for a period of 25 days in confinement conditions of the samples under vacuum and petrographic studies of the characteristics rocks, with emphasis on the microfissural state. The sampled rocks provided low values of radon gas emanation between U 0,2 ppm and 13.6 ppm. The correlations between the various results show that the microporous network of the rock is determinant in the rate of emanation of radon gas, overlapping, including the influence of own levels of U present in the rocks. The results also show that the amount of radon gas emanating from the rock is small enough compared to the decay caused by the amount of {sup 238}U. The proposition of gas emanating relative to the total generated by rocks ranging between 0.4% and a maximum of 4.2%. (author)

  20. MODEL FOR UNSTEADY OF DIFFUSION –ADVECTION OF RADON IN SOIL – ATMOSPHERE

    Directory of Open Access Journals (Sweden)

    Parovik R.I.

    2010-04-01

    Full Text Available We consider a mathematical model for unsteady transport of radon from the constant coefficients in the soil – atmosphere. An explicit analytical solution for this model and built at different times of his profiles.

  1. Radon anomalies prior to earthquakes (1). Review of previous studies

    International Nuclear Information System (INIS)

    Ishikawa, Tetsuo; Tokonami, Shinji; Yasuoka, Yumi; Shinogi, Masaki; Nagahama, Hiroyuki; Omori, Yasutaka; Kawada, Yusuke

    2008-01-01

    The relationship between radon anomalies and earthquakes has been studied for more than 30 years. However, most of the studies dealt with radon in soil gas or in groundwater. Before the 1995 Hyogoken-Nanbu earthquake, an anomalous increase of atmospheric radon was observed at Kobe Pharmaceutical University. The increase was well fitted with a mathematical model related to earthquake fault dynamics. This paper reports the significance of this observation, reviewing previous studies on radon anomaly before earthquakes. Groundwater/soil radon measurements for earthquake prediction began in 1970's in Japan as well as foreign countries. One of the most famous studies in Japan is groundwater radon anomaly before the 1978 Izu-Oshima-kinkai earthquake. We have recognized the significance of radon in earthquake prediction research, but recently its limitation was also pointed out. Some researchers are looking for a better indicator for precursors; simultaneous measurements of radon and other gases are new trials in recent studies. Contrary to soil/groundwater radon, we have not paid much attention to atmospheric radon before earthquakes. However, it might be possible to detect precursors in atmospheric radon before a large earthquake. In the next issues, we will discuss the details of the anomalous atmospheric radon data observed before the Hyogoken-Nanbu earthquake. (author)

  2. Lung cancer incidence after smoking and exposure to radon using a two-mutation model

    International Nuclear Information System (INIS)

    Leenhouts, H.P.

    1997-01-01

    A study to analyze lung cancer in humans as a function of exposure to radon and smoking, used three types of data: population statistics in non-smokers habits of British radiologists and radon exposure of the Colorado uranium miners. Using a simplified two-mutation carcinogenesis model and only six unknown variables yielded a coherent description of lung cancer dependence on exposure to radon and smoking. For risk estimates the radiation effect of radon can be concluded to be highly dependent on smoking habits, e.g. the radiation effect differs (in absolute terms) by a factor of about 7 between non-smokers, but the relative risk is much higher in non-smokers than in smokers. The results to data justify a thorough investigation of the analysis method to realize improved radon risk estimates. (author)

  3. Lung cancer incidence after smoking and exposure to radon using a two-mutation model

    Energy Technology Data Exchange (ETDEWEB)

    Leenhouts, H.P. [RIVM, Bilthoven (Netherlands)

    1997-03-01

    A study to analyze lung cancer in humans as a function of exposure to radon and smoking, used three types of data: population statistics in non-smokers habits of British radiologists and radon exposure of the Colorado uranium miners. Using a simplified two-mutation carcinogenesis model and only six unknown variables yielded a coherent description of lung cancer dependence on exposure to radon and smoking. For risk estimates the radiation effect of radon can be concluded to be highly dependent on smoking habits, e.g. the radiation effect differs (in absolute terms) by a factor of about 7 between non-smokers, but the relative risk is much higher in non-smokers than in smokers. The results to data justify a thorough investigation of the analysis method to realize improved radon risk estimates. (author)

  4. Radon in workplaces

    International Nuclear Information System (INIS)

    Gooding, Tracy

    1995-01-01

    The naturally occurring radioactive gas radon has been found at excessive levels in many workplaces other than mines throughout the country. Prolonged exposure to radon and its decay products increases the risk of developing lung cancer, and controls to protect employees from excessive exposure are included in the Ionising Radiations Regulations 1985. The control of occupational exposure to radon is discussed here. (author)

  5. [Geochemical characteristics of radon and mercury in soil gas in Lhasa, Tibet, China].

    Science.gov (United States)

    Zhou, Xiao-Cheng; Du, Jian-Guo; Wang, Chuan-Yuan; Cao, Zhong-Quan; Yi, Li; Liu, Lei

    2007-03-01

    The geochemical characteristics of radon and mercury in soil gas in Lhasa and vicinity are investigated based on the measurements of Rn and Hg concentrations, and environmental quality for Rn and Hg in soil gas was evaluated by means of the index of geoaccumulation. The data of Rn and Hg of 1 579 sampling site indicate that the values of environmental-geochemical background of Rn and Hg are 7 634.9 Bq/m3, 41.5 ng/m3 with standard deviations of 2.7 Bq/m3, 2.2 ng/m3, respectively. The environmental quality for Rn in soil gas is better in the west and east parts of studied area, but becomes moderate pollution (level III) in the north part of the central area. Rn is derived from radioactive elements in granitic sediments in the intermountain basin and granite base, which are the major sources of pollution. The environmental quality for Hg in soil gas becomes gradually polluted from the suburban to the center of urban, and the highest pollution reaches level IV. The background of Hg in soil gas is mainly controlled by compositions of sediments, but the Hg pollution caused by human waste and religionary use of mercury.

  6. Development of a radiochemical method for analyzing radon gas in uranium mine atmospheres: covering the period February 3, 1975--March 31, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Stein, L.; Shearer, J.A.; Hohorst, F.A.; Markun, F.

    1977-01-14

    A simplified radiochemical method has been developed for quantitatively analyzing radon gas in underground uranium mines. In this method, a measured volume of air is drawn by a pump through a drying tube and a cartridge containing dioxygenyl hexafluoroantimonate reagent. Radon is captured as a nonvolatile product. After radioactive equilibrium has been established between radon and its short-lived daughters (approximately 4 hours), the gamma-emission of the cartridge is measured with a scintillation counter. The amount of radon is then calculated from the gamma-emission rate. The effect of cartridge geometry, reagent load, and air flow rate upon collection efficiency and counting efficiency is reported.

  7. Development of a radiochemical method for analyzing radon gas in uranium mine atmospheres: covering the period February 3, 1975--March 31, 1976

    International Nuclear Information System (INIS)

    Stein, L.; Shearer, J.A.; Hohorst, F.A.; Markun, F.

    1977-01-01

    A simplified radiochemical method has been developed for quantitatively analyzing radon gas in underground uranium mines. In this method, a measured volume of air is drawn by a pump through a drying tube and a cartridge containing dioxygenyl hexafluoroantimonate reagent. Radon is captured as a nonvolatile product. After radioactive equilibrium has been established between radon and its short-lived daughters (approximately 4 hours), the gamma-emission of the cartridge is measured with a scintillation counter. The amount of radon is then calculated from the gamma-emission rate. The effect of cartridge geometry, reagent load, and air flow rate upon collection efficiency and counting efficiency is reported

  8. Radon risk in Alpine regions in Austria: Risk assessment as a settlement planning strategy

    International Nuclear Information System (INIS)

    Gruber, V.; Baumgartner, A.; Seidel, C.; Maringer, F. J.

    2008-01-01

    Soil gas radon measurements complement indispensable and well-established radon indoor measurements in Austria. Radon in soil gas is a result of geochemical conditions as well as of geology, mineralogy, geophysics and meteorology. Therefore, geological factors can help to predict potential indoor radon concentrations via soil gas. Soil gas radon measurements in well-defined geological units give an estimate of local and regional radon hazards and build the basis for radon risk maps, which could be used for land-use planning and urban development. The creation of maps makes an important contribution to health care. For this purpose, several research projects were carried out in Austria. On the one hand, a study was already conducted in Lower Austria to determine the influence of meteorological and soil physical parameters on radon concentrations in soil gas and to evaluate soil gas radon concentrations with a radon emanation and migration model. On the other hand, radon measurements on different geomorphologic formations in the Austrian Alps, which are potential settlement areas, are of special interest. (authors)

  9. Prediction of the net radon emission from a model open pit uranium mine

    International Nuclear Information System (INIS)

    Nielson, K.K.; Perkins, R.W.; Schwendiman, L.C.; Enderlin, W.I.

    1979-04-01

    Radon emission from a model open pit uranium mining operation has been estimated by applying radon exhalation fluxes measured in an open pit uranium mine to the various areas of the model mine. The model mine was defined by averaging uranium concentrations and production and procedural statistics for eight major open pit uranium mines in the Casper, Wyoming area. The resulting emission rates were 740 Ci/AFR during mining operations and 33 Ci/AFR/yr after abandonment of the mine

  10. Presence of soil gas and indoor Radon in volcanic areas located in Latium and Campania Regions, Italy

    International Nuclear Information System (INIS)

    Buccheri, G.; Addonizio, P.; Rinaldini, A.

    2017-01-01

    In Italy, radon highest concentrations concern all Tyrrhenian belt. The abundant distribution of the radioactive elements in Latium and in Campania, often accompanied by emissions of endogenic gas (CO_2, CO and H_2S), is strictly related to quaternary alkali-potassic volcanism. This article reports about connection between Radon presence and geology (which also influences the most used building materials) within two active areas in Latium and Campania Regions (Italy). Colli Albani are located in Latium. This area is considered as a quiescent volcano, whose last eruptive phase dates back to 41-36 kya, with deposition of Peperino di Albano, a lithoid granular tuff that Romans commonly used as a building and decorative material (lapis albanus). Campania is the second Region of Italy as for population (and more than 50 % of its 6 million of inhabitants are concentrated in the Province of Naples), and volcanism is mainly connected there to the presence of a deep and large volcanic complex, related to a mantle anomaly. INAIL is busy in research activity for evaluation and management of risk for health at workplaces, connected to exposure to indoor radon, taking into account of active laws. Starting from knowledge about geologic activity in Latium and in Campania, the aim of INAIL research activity is estimation of hazard, because of Rn, CO_2 and other endogenic toxic gases, at workplaces located in both Regions. In order to estimate risk from Radon, INAIL carried out soil gas measurements in Alban Hills area, and one more series of Radon measurements has been planned downtown in Naples, where many commercial and artisanal activities are located underground (mainly in tuffaceous buildings). According to the indications provided by the Directive 2013/59/Euratom, INAIL measurements will be aimed to realize Radon Potential Maps (RPM), that may help Italian Institutions to identify hazard areas, realize an effective territorial plan and to assess health risk. (authors)

  11. Uptake of the natural radioactive gas radon by an epiphytic plant.

    Science.gov (United States)

    Li, Peng; Zhang, Ruiwen; Gu, Mintian; Zheng, Guiling

    2018-01-15

    Radon ( 222 Rn) is a natural radioactive gas and the major radioactive contributor to human exposure. The present effective ways to control Rn contamination are ventilation and adsorption with activated carbon. Plants are believed to be negligible in reducing airborne Rn. Here, we found epiphytic Tillandsia brachycaulos (Bromeliaceae) was effective in reducing airborne Rn via the leaves. Rn concentrations in the Rn chamber after Tillandsia plant treatments decreased more than those in the natural situation. The specialized foliar trichomes densely covering Tillandsia leaves play a major role in the uptake of Rn because the amplified rough leaf surface area facilitates deposition of Rn progeny particles and the powdery epicuticular wax layer of foliar trichomes uptakes liposoluble Rn. The results provide us a new ecological strategy for Rn contamination control, and movable epiphytic Tillandsia plants can be applied widely in Rn removal systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Model for the assessment of surface radionuclide 210 Pb contamination indoors due to presence of radon

    International Nuclear Information System (INIS)

    Mrdja, D.; Bikit, I.; Forkapic, S.

    2009-01-01

    The model is based on the fact that the change of indoor radon concentration, which periodically enters the room, affects only on radioactive decay and the inserted amount of radon in each impact, but not on its diffusion out, i.e. escape from the room. The aim of the model is to assess the surface contamination of the room by lead 210 Pb. (author) [sr

  13. The application of artificial neural network in radon disaster model of uranium mining

    International Nuclear Information System (INIS)

    Zhu Yufeng; Zhu Guogen; Zhou Shijian

    2012-01-01

    The structural features, data analysis and learning process of feed-forward neural network (BP ANN) were analyzed at first. Rodon sample from Fuzhou Jinan Uranium Industry Limited Company were used to training the network and make the forecast then, and a forecasting model was established for the radon disaster in uranium mines. The method and effectiveness of BP neural network in predicting radon disaster was discussed. The test of training samples showed that the BP network had gotten fairly satisfied result in predicting mine radon disaster. (authors)

  14. Logistic regression model for detecting radon prone areas in Ireland.

    Science.gov (United States)

    Elío, J; Crowley, Q; Scanlon, R; Hodgson, J; Long, S

    2017-12-01

    A new high spatial resolution radon risk map of Ireland has been developed, based on a combination of indoor radon measurements (n=31,910) and relevant geological information (i.e. Bedrock Geology, Quaternary Geology, soil permeability and aquifer type). Logistic regression was used to predict the probability of having an indoor radon concentration above the national reference level of 200Bqm -3 in Ireland. The four geological datasets evaluated were found to be statistically significant, and, based on combinations of these four variables, the predicted probabilities ranged from 0.57% to 75.5%. Results show that the Republic of Ireland may be divided in three main radon risk categories: High (HR), Medium (MR) and Low (LR). The probability of having an indoor radon concentration above 200Bqm -3 in each area was found to be 19%, 8% and 3%; respectively. In the Republic of Ireland, the population affected by radon concentrations above 200Bqm -3 is estimated at ca. 460k (about 10% of the total population). Of these, 57% (265k), 35% (160k) and 8% (35k) are in High, Medium and Low Risk Areas, respectively. Our results provide a high spatial resolution utility which permit customised radon-awareness information to be targeted at specific geographic areas. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Modelization of the radon emanation from natural sources in the soil

    International Nuclear Information System (INIS)

    Sabir, A.; Marah, H.; Hlou, L.; Klein, D.; Chambaudet, A.

    1996-01-01

    To evaluate the radon emanation and hence the risk to populations, we have adapted an original mathematical model based on the method of distribute parcels (L. Hlou, These d'etat, Faculte des Sciences, Kenitra, MAROC, 1994). This allows us to follow the migration, in time and space, of a quantity of radon produced in a unit volume as a function of the geological, morphological and structural characteristics of the site studied. Knowing the petrographic and pedologic parameters enables us to calculate the radon concentration in all points inside the soil of the site as well as the radon emanation in the atmosphere. It is therefore possible to calculate the radiological risk for populations brought to live on the site studied. Different applications of this model have been realised in Morocco and in France to demonstrate its efficiency. (author)

  16. Indoor radon risk potential of Hawaii

    International Nuclear Information System (INIS)

    Reimer, G.M.; Szarzi, S.L.

    2005-01-01

    A comprehensive evaluation of radon risk potential in the State of Hawaii indicates that the potential for Hawaii is low. Using a combination of factors including geology, soils, source-rock type, soil-gas radon concentrations, and indoor measurements throughout the state, a general model was developed that permits prediction for various regions in Hawaii. For the nearly 3,100 counties in the coterminous U.S., National Uranium Resource Evaluation (NURE) aerorad data was the primary input factor. However, NURE aerorad data was not collected in Hawaii, therefore, this study used geology and soil type as the primary and secondary components of potential prediction. Although the radon potential of some Hawaiian soils suggests moderate risk, most houses are built above ground level and the radon soil potential is effectively decoupled from the house. Only underground facilities or those with closed or recirculating ventilation systems might have elevated radon potential. (author)

  17. Short- and long-term monitoring of radon, thoron and carbon dioxide in soil-gas at Altos de pipe, Venezuela

    International Nuclear Information System (INIS)

    LaBrecque, J.J.; Cordoves, P.R.

    2004-01-01

    Radon and thoron activities in soil-gases have been measured since July 9, 1997 Cariaco earthquake (Mw=6.9) until the end of 2000. Carbon dioxide concentrations were also monitored between 1998-2000. The soil-gas was collected between 50-55 cm depths at two sampling points at Altos de pipe (Instituto Venezolano de Investigaciones Cientificas-IVIC) near Caracas, Venezuela. The radon and thoron measurements were performed daily employing radiation monitors with scintillation cells and the carbon dioxide was monitored with portable gas analyzers. Average weekly and monthly values were calculated and plotted for this three-four year period. In general, both the radon and carbon dioxide values showed sinusoidal trends due to seasonal changes. During the dry season the radon and carbon dioxide values decreased, while the radon activity was relative constant (flat) during the rainy season at one of the sampling points. Only two monthly radon values were seen to be anomalous in the graphs in respect to seven anomalous periods for the average weekly values. No anomalous periods were clearly seen for carbon dioxide. Finally, it was difficult to try to relate these radon anomalous periods with specific earthquakes due to the large number of minor earthquakes during these years, but it seem that the minor earthquake (Mb=5.9) of October 4, 2000 could be associated with the radon anomalous period in September, when there were no other minor earthquakes (Mb≥4.0). (author)

  18. Modelling and experimental study of the behavior of radon and radon decay products in an enclosure. Application to houses; Modelisation et etude experimentale du comportement du radon et de ses descendants dans une enceinte confinee. Application a une habitation

    Energy Technology Data Exchange (ETDEWEB)

    Gouronnec, A M

    1995-02-03

    Since the eighties, more and more studies were performed about radon and its decay products in houses with one of the aim being the estimation of the dose received by their inhabitants. Then, the principal objective of this work is to describe the behaviour of radon and its decay products within a dwelling. In the first part to the report, a few definitions are given and data from literature give an idea of indoor radon and radon decay products activities and/or size distribution. Aspects of dosimetry are presented too. In the second part of the work, a mathematical model, called `PRADDO` of Physic of Radon and radon Decay products in Domestic environment is developed on the basis of the classical model written by Jacobi in 1972. On the one hand, it has to predict radon decay products activities in systems consisting in one or more enclosure(s), from radon activity and from ambient aerosol concentration and size distribution. On the other hand, one part of the model is assigned to study the influence of the entry model parameters variation on the calculated quantities. Then, in the third part of the work, two experimental studies are realised in order to compare measurements to modelization. The first experimentation is a laboratory work, made on the test bench ICARE from IPSN, and the second one consists in describing the basement of an occupied house from Brittany. In the two cases, the comparison between experiments and modelling shows a good agreement if particles are present in the air, but any conclusion is made when is no aerosol in the enclosure. (author). 158 refs., 81 figs., 42 tabs.

  19. EMISSION OF SOIL GAS RADON CONCENTRATION AROUND MAIN CENTRAL THRUST IN UKHIMATH (RUDRAPRAYAG) REGION OF GARHWAL HIMALAYA.

    Science.gov (United States)

    Aswal, Sunita; Kandari, Tushar; Sahoo, B K; Bourai, A A; Ramola, R C

    2016-10-01

    In this paper, the result of systematic measurement of the soil gas radon concentrations is discussed and the background values are defined along and around the Main Central Thrust (MCT) in Ukhimath region of Garhwal Himalaya, India. The Ukhimath region is being subjected to intense neotectonic activities like earthquake and landslide. For the systematic study, the measurement has been done in grid pattern form along and across the MCT. The soil gas radon concentrations were measured using RAD7 with appropriate accessories and followed proper protocol proposed by the manufacturer. The soil gas concentration was measured at different depths 10, 30 and 50 cm with a wide range of different points from the MCT. At 10 cm depth, the soil gas radon concentration was found to vary from 125 to 800 Bq m -3 with an average of 433 Bq m -3 ; at 30 cm, it was found to vary from 203 to 32 500 Bq m -3 with an average of 2387 Bq m -3 ; and at 50 cm, it was found to vary from 1330 to 46 000 Bq m -3 with an average of 15 357 Bq m -3 The data analysis clearly reveals anomalous values along the fault. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Emission of soil gas radon concentration around main central thrust in Ukhimath (Rudraprayag) region of Garhwal Himalaya

    International Nuclear Information System (INIS)

    Aswal, Sunita; Kandari, Tushar; Bourai, A.A.; Ramola, R.C.; Sahoo, B.K.

    2016-01-01

    In this paper, the result of systematic measurement of the soil gas radon concentrations is discussed and the background values are defined along and around the Main Central Thrust (MCT) in Ukhimath region of Garhwal Himalaya, India. The Ukhimath region is being subjected to intense neotectonic activities like earthquake and landslide. For the systematic study, the measurement has been done in grid pattern form along and across the MCT. The soil gas radon concentrations were measured using RAD7 with appropriate accessories and followed proper protocol proposed by the manufacturer. The soil gas concentration was measured at different depths 10, 30 and 50 cm with a wide range of different points from the MCT. At 10 cm depth, the soil gas radon concentration was found to vary from 125 to 800 Bq m -3 with an average of 433 Bq m -3 ; at 30 cm, it was found to vary from 203 to 32 500 Bq m -3 with an average of 2387 Bq m -3 ; and at 50 cm, it was found to vary from 1330 to 46 000 Bq m -3 with an average of 15 357 Bq m -3 . The data analysis clearly reveals anomalous values along the fault. (authors)

  1. AlphaGUARD, the new reference for continuous radon monitoring in air, soil, gas, water and material

    International Nuclear Information System (INIS)

    Roessler, F.; Buerkin, W.; Villert, J.

    2016-01-01

    The company Saphymo GmbH has more than 25 years of experience in the field of radon measurement. More than 20 years ago Saphymo developed the professional and robust radon monitor AlphaGUARD, quickly recognized as a standard for reliable and continuous measurements of the radon concentration. Today AlphaGUARD is internationally established as the reference in radon measurement. Following up on this success story the new generation of AlphaGUARD can now be presented. Based on the excellent measurement characteristics of its predecessor the new AlphaGUARD combines the well-proven principle of the pulse ionisation chamber with new and additional features. The robust housing is oriented on the well-proven design of the predecessor and includes now an integrated flow controlled and powerful pump. The instrument can be operated in flow as well as in diffusion mode (without pump). Via the new large display and the intuitive menu navigation all measurement data can be retrieved. The presentation of time series in charts is possible as well as the parametrisation of the instrument. A wide range of accessories, developed in cooperation with various radon experts of universities and laboratories, enables the user a varied and flexible application of the AlphaGUARD: Measurement of the radon concentration in air (radon, thoron, radon progenies), in water (sampling and time resolved measurements) and in soil (soil gas measurements, exhalation measurements), emanation measurements from material, multi spot measurement, online measurement with remote data transmission via Ethernet/DSL, Bluetooth, Wi-Fi, GPRS/3G or satellite. Due to its high sensitivity and its fast and linear response over a large measuring range the AlphaGUARD is excellently suited for calibration laboratories. Furthermore the AlphaGUARD enables ideal prerequisites for field applications: robust housing for operations under harsh conditions, long battery life for the measurement at any location, low

  2. Comparison between the measurements of Radon Gas Concentrations and γ-ray intensities in Exploring the Black Sands at El-Burullus Beach

    International Nuclear Information System (INIS)

    Abdel-Razek, Y.A; Bakhit, A.F

    2009-01-01

    Ten well-located monitoring stations along El-Burullus beach were chosen to measure radon gas concentrations in the beach sands below surface, and γ-ray intensities at 10 cm above the surface. These stations were chosen to represent apparent concentrations of the black sands. Sand samples were collected from the different stations and analyzed to study the relation between the concentrations of the heavy minerals and the measured radon concentrations or the measured γ-ray intensities at these stations. It was found that radon gas concentrations measured at 6:00 Pm were about 2.82 times those measured at 1 :00 Pm due to diurnal variation of temperature. Measurements of radon gas concentrations inside the beach sands are found to be more reliable in qualitative exploration of black sands than the measurements of γ-ray intensities above the shore sands due to the random arrangement of the layers of these sands below surface

  3. Why measure radon decay products?

    International Nuclear Information System (INIS)

    Rolle, R.; Lettner, H.

    1997-01-01

    Combined development in spectrometry, instrumentation and ventilation modelling with its dependence on short- and long-term weather fluctuations renders possible a new, economical metrology for radon decay products. Short-term measurements can, with few restrictions, be converted to annual exposures of an accuracy superior to that from conventional medium-term Rn gas measurements. (orig.) [de

  4. Uranium mineralization distribution sounding at ANO CRN.1-ANO CG.6 Mentawa sector using radon gas measurement

    International Nuclear Information System (INIS)

    Paimin; Sartapa; Darmono, S.

    2000-01-01

    The investigation was based on Systematic Prospection (1996,1997) at Mentawa River and Ampola up stream which were found radiometry anomalous about 750-15.000 c/s on the metasilt outcrop. Form of uranium mineralization is uraninite which associate with tourmaline, quartz, and sulphide and fills WNW-ESE fracture. The aims of investigation were to know uranium mineralization in sub surface by radon gas measurement, surface radiometry, and topographical mapping. (author)

  5. An evaluation of the quantitative effects on radon gas from the modification of a home heating and air conditioning system

    International Nuclear Information System (INIS)

    Montague, A.

    1991-01-01

    The quantitative effects associated with the design, construction, operation, environmental and meteorological conditions on radon gas levels in a typical residential dwelling with a basement, having a measured radon level of approximately 20 pico-curies/liter (pCi/L), are evaluated. After several mechanical and electrical modifications are made on the dwelling's heating system, two different furnace breathing modes are studied. The effect on radon levels in the dwelling are observed as the furnace receives all of its combustion, draft and ventilation air - as the experiment alternates, on a bi-weekly basis - from inside and then outside the dwelling. Radon, barometric pressure, outside temperature, relative humidity, wind-speed and direction are monitored continuously; special household activity in the dwelling is also observed. A novel differential air pressure technique is used to measure inside versus outside house air pressure variations, twice each day, resulting from meteorological conditions, dwelling activity, and the furnace breathing mode. A rigorous statistical analysis is employed that includes sequential linear regression of time-series data, trend corrections to remove variations that contribute to the variance in the data without addition useful information. A novel approach using an electrical analog, to screen out unwanted variations is applied, by utilizing a computer routine to simulate the effect of an electronic RC filter, to achieve the desired analytical discrimination

  6. Enrichment of radon and carbon dioxide in the open atmosphere of an Australian coal seam gas field.

    Science.gov (United States)

    Tait, Douglas R; Santos, Isaac R; Maher, Damien T; Cyronak, Tyler J; Davis, Rachael J

    2013-04-02

    Atmospheric radon ((222)Rn) and carbon dioxide (CO2) concentrations were used to gain insight into fugitive emissions in an Australian coal seam gas (CSG) field (Surat Basin, Tara region, Queensland). (222)Rn and CO2 concentrations were observed for 24 h within and outside the gas field. Both (222)Rn and CO2 concentrations followed a diurnal cycle with night time concentrations higher than day time concentrations. Average CO2 concentrations over the 24-h period ranged from ~390 ppm at the control site to ~467 ppm near the center of the gas field. A ~3 fold increase in maximum (222)Rn concentration was observed inside the gas field compared to outside of it. There was a significant relationship between maximum and average (222)Rn concentrations and the number of gas wells within a 3 km radius of the sampling sites (n = 5 stations; p gas field related to both point (well heads, pipelines, etc.) and diffuse soil sources. Radon may be useful in monitoring enhanced soil gas fluxes to the atmosphere due to changes in the geological structure associated with wells and hydraulic fracturing in CSG fields.

  7. Systematic effects in radon mitigation by sump/pump remediation

    International Nuclear Information System (INIS)

    Groves-Kirkby, C.J.; Denman, A.R.; Groves-Kirkby, C.J.; Woolridge, A.C.; Woolridge, A.C.; Phillips, P.S.; Crockett, R.G.M.; Tornberg, R.

    2006-01-01

    Sump/Pump remediation is widely used in the United Kingdom to mitigate indoor radon gas levels in residential properties. To quantify the effectiveness of this technology, a study was made of radon concentration data from a set of 173 homes situated in radon Affected Areas in and around Northamptonshire, U.K., re-mediated using conventional sump/pump technology. This approach is characterised by a high incidence of satisfactory mitigation outcomes, with more than 75% of the sample exhibiting mitigation factors (defined as the ratio of radon concentrations following and prior to remediation) of 0.2 or better. There is evidence of a systematic trend, where houses with higher initial radon concentrations have higher mitigation factors, suggesting that the total indoor radon concentration within a dwelling can be represented by two components, one susceptible to mitigation by sump/pump remediation, the other remaining essentially unaffected by these remediation strategies. The first component can be identified with ground-radon emanating from the subsoil and bedrock geologies, percolating through the foundations of the dwelling as a component of the soil-gas, potentially capable of being attenuated by sump/pump or radon-barrier remediation. The second contribution is attributed to radon emanating from materials used in the construction of the dwelling, principally concrete and gypsum plaster-board, with a further small contribution from the natural background level, and is essentially unaffected by ground-level remediation strategies. Modelling of such a two-component radon dependency using realistic ground-radon attenuation factors in conjunction with typical structural-radon levels yields behaviour in good agreement with the observed inverse-power dependence of mitigation factor on initial radon concentration. (authors)

  8. Men and radon - a noble gas of many disguise - Part I and Part II

    International Nuclear Information System (INIS)

    Momcilovic, B.; Lykken, G. I.

    2005-01-01

    Radon-induced lung cancer can be traced back to the 16th century miners in Europe, but recently there has been a world wide concern that elevated radon progeny levels in dwellings may also be implicated in lung cancer. Historical and experimental evidence is presented to document how inhaled radon is distributed throughout the body and stored in fats and lipids. Background counts in a steel room using a human whole-body counter (HWBC) progressively decreased throughout the day, which is attributed to a lowering of radon as subjects entered the steel room. The observed increases in potassium-40 (4 0K ) counts in marathon runners was attributed to inhalation of environmental radon, and radon progeny was verified by measuring contributions to the 4 0K photopeak by 2 14B i in cyclists and an untrained subject who exercised in a room with radon-laden air. Effective half-lives and regional 2 14B i emissions were found to be the highest in the areas of the head (brain) and stomach (omentum) when filtered radon-laden air was inhaled. These observations prompted analyses for radon progeny (2 10B i and 2 10P o) from brain tissues of persons who suffered from Alzheimer's and Parkinson's Diseases (AD and PD). Protein in AD and lipids in PD were high in these progeny relative to the control tissues. Whole body counts (2 14B i emissions) of subjects over a period of 24 years were analysed for radon body content (Rn-conc). Statistically significant correlations were found between total body fat and Rn-conc in women and between seasonal home radon concentrations and seasonal Rn-conc in subjects participating in community-based studies. It is concluded that environmental radon is indeed stored in the body, that body concentration correlates with body fat in women, and that these reflect seasonal concentrations in their dwellings. Radon decay products include a number of alpha and beta particle emitters. These emissions produce a radiation risk and may play a role in multiple

  9. Effects of various tailings covers on radon gas emanation from pyritic uranium tailings

    International Nuclear Information System (INIS)

    Dave, N.K.; Lim, T.P.

    1987-01-01

    Radon emanation studies were carried out at an inactive pyritic uranium tailings site in Elliot Lake, Ontario, Canada, to evaluate the effects of various existing dry and wet covers on radon flux rates. Measurements were taken using activated charcoal cartridges for various surface covers consisting of bare, vegetated, acidophilic moss with high degree of water saturation, compacted crushed rock and gravel, and winter snow. The results showed that at a given site, there was no significant difference in radon emanation rates between various tailings covers and bare tailings. In particular, no increase In radon emanation rates from vegetated areas compared to bare tailings was observed. Radon emanation rates varied spatially depending on tailings grain size, porosity, moisture content and on pressure and water table variations. The emanation rates were higher for tailings with low water contents compared to those for wet and moss covered tailings

  10. Levels of radon gas concentration and progeny in homes of Potosi City, Bolivia to 4000 m; Niveles de concentracion de gas radon y progenie en viviendas de la Ciudad de Potosi, Bolivia a 4000 msnm

    Energy Technology Data Exchange (ETDEWEB)

    Mamani M, R. [Universidad Autonoma Tomas Frias, Carrera de Fisica, Av. del maestro s/n, Edif. Central Potosi, Villa Imperial de Potosi (Bolivia, Plurinational State of); Claros J, J. [Universidad Autonoma Tomas Frias, Facultad de Minas Potosi, Centro de Investigacion, Av. Serrudo y Arce s/n, Villa Imperial de Potosi (Bolivia, Plurinational State of); Vasquez A, R., E-mail: raulm2k13@hotmail.com [Instituto Boliviano de Biologia de Altura, Calle Hoyos 953, La Paz (Bolivia, Plurinational State of)

    2015-10-15

    Full text: In this work the presence of radon gas was determined, which is a radioactive contaminant that comes from underground, able to penetrate the houses. The danger is that when mixed air and when inhaled can cause serious damage to the lungs, for the short life time that has radon and progeny for decay, damaging the pulmonary alveoli and reducing breathing capacity of the habitants, then causing polycythemia in some cases. The study was carried out in homes in the city of Potosi, Bolivia located at 4000 m. The quantification of radon gas and progeny was performed with the equipment Alpha-Zaeller-2 (Az-2), quantification was realized in 6 zones of the city of Potosi, chosen randomly. In each zone were carried out measurements in 40 homes (2 rooms more permanent), both day and night, for a period of 3 days in two different seasons and with concentrations of average humidity of 20, 50 and 80%. The values obtained for each period vary depending on the season and 30 to 50% of the allowable values given by the EPA and Who for housing. (Author)

  11. Distance to faults as a proxy for radon gas concentration in dwellings.

    Science.gov (United States)

    Drolet, Jean-Philippe; Martel, Richard

    2016-02-01

    This research was done to demonstrate the usefulness of the local structural geology characteristics to predict indoor radon concentrations. The presence of geologic faults near dwellings increases the vulnerability of the dwellings to elevated indoor radon by providing favorable pathways from the source uranium-rich bedrock units to the surface. Kruskal-Wallis one-way analyses of variance by ranks were used to determine the distance where faults have statistically significant influence on indoor radon concentrations. The great-circle distance between the 640 spatially referenced basement radon concentration measurements and the nearest fault was calculated using the Haversine formula and the spherical law of cosines. It was shown that dwellings located less than 150 m from a major fault had a higher radon potential. The 150 m threshold was determined using Kruskal-Wallis ANOVA on: (1) all the basement radon measurements dataset and; (2) the basement radon measurements located on uranium-rich bedrock units only. The results indicated that 22.8% of the dwellings located less than 150 m from a fault exceeded the Canadian radon guideline of 200 Bq/m(3) when using all the basement radon measurements dataset. This percentage fell to 15.2% for the dwellings located between 150 m and 700 m from a fault. When using only the basement radon measurements located on uranium-rich bedrock units, these percentages were 30.7% (0-150 m) and 17.5% (150 m-700 m). The assessment and management of risk can be improved where structural geology characteristics base maps are available by using this proxy indicator. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Monitoring of radon variation in both ground water and soil gas along Al-Ghab fault from 15 February to 23 June 1992

    International Nuclear Information System (INIS)

    Al-Hilal, M..; Al-Hent, R.

    1992-11-01

    The purpose of this report is to check the possibility of using radon monitoring technique which has been established as an additional aid for earthquake prediction elsewhere in the world, and to indicate whether radon measurements will frequently be useful in allowing the prediction of earthquakes along the seismically active Al-Ghab fault, in the western side of Syria. A network of ten sampling stations were setup along Al-Ghab fault segment for monitoring radon variations in both groundwater and soil gas. Sampling frequency was about once every three weeks. The overall results of this scientific study suggest the possibility of employing radon technique as a fairly good precursor in the Syrian earthquake prediction programme. To achieve this, however, a continuous monitoring of radon changes is required in groundwater and soil gas as well as other environmental variable especially air temperature, barometric pressure and wind velocity. Suitable grid patterns over the major seismic zones in Syria are necessary for obtaining the most reliable radon data. The establishment of seismic network in the region is extremely important for correlating radon data with the seismic activity records. (author). 4 refs., 7 figs., 3 tabs

  13. Modelling of radon control and air cleaning requirements in underground uranium mines

    International Nuclear Information System (INIS)

    El Fawal, M.; Gadalla, A.

    2014-01-01

    As a part of a comprehensive study concerned with control workplace short-lived radon daughter concentration in underground uranium mines to safe levels, a computer program has been developed and verified, to calculate ventilation parameters e.g. local pressures, flow rates and radon daughter concentration levels. The computer program is composed of two parts, one part for mine ventilation and the other part for radon daughter levels calculations. This program has been validated in an actual case study to calculate radon concentration levels, pressure and flow rates required to maintain acceptable levels of radon concentrations in each point of the mine. The required fan static pressure and the approximate energy consumption were also estimated. The results of the calculations have been evaluated and compared with similar investigation. It was found that the calculated values are in good agreement with the corresponding values obtained using ''REDES'' standard ventilation modelling software. The developed computer model can be used as an available tool to help in the evaluation of ventilation systems proposed by mining authority, to assist the uranium mining industry in maintaining the health and safety of the workers underground while efficiently achieving economic production targets. It could be used also for regulatory inspection and radiation protection assessments of workers in the underground mining. Also with using this model, one can effectively design, assess and manage underground mine ventilation systems. Values of radon decay products concentration in units of working level, pressures drop and flow rates required to reach the acceptable radon concentration relative to the recommended levels, at different extraction points in the mine and fan static pressure could be estimated which are not available using other software. (author)

  14. Modeling the dependency of radon concentration levels inside ancient Egyptian tombs on the ambient temperature variations

    Energy Technology Data Exchange (ETDEWEB)

    Metwally, S M; Abo-Elmagdb, M [Faculty of Science, Department of Physics, Ain Shams University, P. O. Box 11566, Cairo (Egypt); Salamaa, E [National Institute for Standard, Radiation Measurements Department, Cairo (Egypt)

    2007-06-15

    Radon concentration inside partially closed places like dwellings, caves and tombs, depends on many parameters. Some parameters are known quantitatively as radon exhalation rate for walls, decay constant, surface to volume ratio and outdoor concentration while other parameters as ventilation rate is in common known qualitatively due to useless of traditional methods (tracer gases) in many places as ancient Egyptian tombs. This work introduces a derived mathematical model to evaluate the sensitivity of radon concentration levels inside single sided opening places as ancient Egyptian tombs on the ambient temperature differences. The obtained formula for the natural ventilation rate depends on the indoor and outdoor temperature difference and the geometrical dimensions of the doorway. The effects of in and out flow mixing, air viscosity, streamline contraction, swirling flow and turbulence, were taken into consideration in terms of an empirical correction factor. According UNSCEAR reports, the exhalation rate {phi}=C{sub ra}{lambda}{sub rn} f{rho}{sub s}(1-{epsilon})L; C{sub ra} the effective radium content, {lambda}{sub rn} decay constant, f emanation fraction, {rho}{sub s} soil grain density, {epsilon} porosity and L diffusion length, these are approximately static parameters but the variability of ambient temperature introduces a source of energy of fluctuating strength to radon atoms in rocks which controls the flow rate and the ambient content of radon. Therefore, the change of outdoor and indoor temperature difference causes fluctuation of value and direction of volume flow rate in such places consequently causes the daily variation and on average the seasonal variation of radon concentration. Therefore according to the present model, the daily accurate expectation of radon concentrations inside ancient Egyptian tombs, require precise measurements of indoor and outdoor temperatures.

  15. Modeling the dependency of radon concentration levels inside ancient Egyptian tombs on the ambient temperature variations

    International Nuclear Information System (INIS)

    Metwally, S.M.; Abo-Elmagdb, M.; Salamaa, E.

    2007-01-01

    Radon concentration inside partially closed places like dwellings, caves and tombs, depends on many parameters. Some parameters are known quantitatively as radon exhalation rate for walls, decay constant, surface to volume ratio and outdoor concentration while other parameters as ventilation rate is in common known qualitatively due to useless of traditional methods (tracer gases) in many places as ancient Egyptian tombs. This work introduces a derived mathematical model to evaluate the sensitivity of radon concentration levels inside single sided opening places as ancient Egyptian tombs on the ambient temperature differences. The obtained formula for the natural ventilation rate depends on the indoor and outdoor temperature difference and the geometrical dimensions of the doorway. The effects of in and out flow mixing, air viscosity, streamline contraction, swirling flow and turbulence, were taken into consideration in terms of an empirical correction factor. According UNSCEAR reports, the exhalation rate Φ=C ra λ rn fρ s (1-ε)L; C ra the effective radium content, λ rn decay constant, f emanation fraction, ρ s soil grain density, ε porosity and L diffusion length, these are approximately static parameters but the variability of ambient temperature introduces a source of energy of fluctuating strength to radon atoms in rocks which controls the flow rate and the ambient content of radon. Therefore, the change of outdoor and indoor temperature difference causes fluctuation of value and direction of volume flow rate in such places consequently causes the daily variation and on average the seasonal variation of radon concentration. Therefore according to the present model, the daily accurate expectation of radon concentrations inside ancient Egyptian tombs, require precise measurements of indoor and outdoor temperatures

  16. Evaluation of the open vial method in the radon measurement

    International Nuclear Information System (INIS)

    Lopez del Rio, H.; Davila R, J. I.; Mireles G, F.

    2014-10-01

    The open vial method is a simple technique, under-utilized but that take advantage of the great radon solubility in organic solvents, therefore applies in the measurement of the radon concentration exhaled in soil. The method consists on the exposition to the gas radon of an open vial with scintillating solution. An integral mathematical model for indoors that describes the emanation processes and gas radon exhalation was developed, as well as the radon dissolution in the scintillation liquid, besides obtaining the characteristic parameters of the experimental system proposed for the radon concentration calculation exhaled by soils. Two experimental arrangements were designed with exposition cameras of 12 and 6 L and quantity of different soil. The open vial was prepared with a mixture of 8 ml of deionized water and 12 ml of scintillation liquid OptiPhase Hi Safe 3 in polyethylene vials; the measurements of the dissolved radon were carried out in scintillation liquid equipment. As a result, on average 2.0% of the exhaled radon is dissolved in the open vial and the dissolved fraction is independent of the experimental arrangement. Also was observed that the exposition time does not affect the radon dissolution significantly, in correspondence with the reported in the literature. (Author)

  17. Radon Concentration in Outdoors and Indoors Around the Flare in Oil Mine Sites; Konsentrasi Gas Radon di Udara di Luar dan Dalam Rumah Sekitar Nyala-api Kawasan Tambang Minyak

    Energy Technology Data Exchange (ETDEWEB)

    Sutarman,; Wahyudi, [Centre for Research and Development of Radiation Safety and Nuclear Biomedicine, National Nuclear Energy Agency, Jakarta (Indonesia); Luhantara, [University of Indonesia, Jakarta (Indonesia)

    2003-03-15

    The flares are much found at the oil exploration areas which appear the combustion gases emission to the environment that pass through a pipe at about 8 m high from the ground level. The flare is released into the environment together with the hydrocarbon and radon gases. This study has been carried out the measurement of the radon gas concentration only. Radon is a radioactive gas which comes from the natural radioactive decay of uranium ({sup 238}U). The outdoor radon concentrations were measured in 23 locations with the two-filter method. The locations were determined by a circle which the flare as the point center. The outdoor radon concentrations were measured in 74 houses (more than distance of 600 m from the flare) with the alpha track detector (CR-39) placed in the living rooms for about three months. The measurements of the radon concentrations were carried out in Cepu, Cirebon, and Prabumulih oil mine sites. The results showed that the outdoor radon concentrations a range of 108 Bq/m{sup 3} to 256 Bq/m{sup 3} in Cepu, 248 Bq/m{sup 3} to 3525 Bq/m{sup 3} in Cirebon, and 51 Bq/m{sup 3} to 114 Bq/m{sup 3} in Prabumulih. The results showed that the indoor radon concentrations a range of 11 Bq/m{sup 3} to 38 Bq/m{sup 3} in Cepu, 28 Bq/m{sup 3} to 184 Bq/m{sup 3} in Cirebon, and 12 Bq/m{sup 3} to 38 Bq/m{sup 3} in Prabumulih. The data of the maximum radon concentration in outdoor air was higher than an actual level which recommended by International Atomic Energy Agency (IAEA) for workplaces. The maximum radon concentration in indoor air was lower than an actual level which recommended by IAEA for dwellings. IAEA recommends the actual level of 1000 Bq/m{sup 3} for workplaces and 200 Bq/m{sup 3} for dwellings. These data will be used for the baseline data of the environmental radioactivity in Indonesia. (author)

  18. Preliminary study of the contamination by Radon Gas in dwelling enclosures in Costa Rica

    International Nuclear Information System (INIS)

    Loria, L.G.; Jimenez, R.; Gallardo, M.C.

    1993-01-01

    The use of Solid State Nuclear Track detectors (SSNTD), LR-115 type II-Quick, is one of the convenient technique to assess the average radiation levels of alpha activities in the environment. This technique has been used to assess the Radon concentration in some areas of San Jose, Costa Rica. Exposed SSNTD films are chemically etched in an alkaline solution and the density of alpha tracks are given as concentration (pCi/L) of Radon. The only known health effect associated with exposure to elevated levels of Radon is an increased risk of developing lung cancer. (authors). 10 refs, 4 figs, 3 tabs

  19. Scopingreport radon

    International Nuclear Information System (INIS)

    Blaauboer, R.O.; Vaas, L.H.; Hesse, J.M.; Slooff, W.

    1989-09-01

    This report contains general information on radon concerning the existing standards, sources and emissions, the exposure levels and effect levels. lt serves as a basis for the discussion during the exploratory melting to be held in November/December 1989, aimed at determining the contents of the Integrated Criteria Document Radon. Attention is focussd on Rn-222 (radon) and Rn-220 (thoron), presently of public interest because of radon gas pollution in private homes. In the Netherlands air quality standards nor product standards for the exhalation rate of building materials have been recommended. The major source of radon in the Netherlands is the soil gas (> 97%), minor sources are phosphate residues and building materials (> 2% in total). Hence, the major concern is the transfer through the inhalation of air, the lung being the most critical organ at risk to develop cancer. Compared to risks for humans, the risks of radon and its daughters for aquatic and terrestric organisms, as well as for agricultural crops and livestock, are assumed to be limited. In the Netherlands the average dose for man due to radon and thoron progeny is appr. 1.2 mSv per year, the estimated dose range being 0.1-3.5 mSv per year. This dose contributes for about 50% to rhe total exposure due to all sources of ionizing radiation. Of this dose respectively 80% is caused by radon and about 90% is received indoor. The estimated dose for the general population corresponds to a risk for inducing fatal cancers of about 15 x 10-6 per year, ranging from 1.2 x 10-6 to 44 x 10-6 which exceeds the risk limit of 1 x 10-6 per year -as defined in the standardization policy in the Netherlands for a single source of ionizing radiation-with a factor 15 (1- 44). Reduction of exposure is only possible in the indoor environment. Several techniques have been described to reduce the indoor dose, resulting from exhalation of the soil and building materials. )aut- hor). 37 refs.; 3 figs.; 8 tabs

  20. Raetrad model extensions for radon entry into multi-level buildings with basements or crawl spaces.

    Science.gov (United States)

    Nielson, K K; Rogers, V C; Rogers, V; Holt, R B

    1997-10-01

    The RAETRAD model was generalized to characterize radon generation and movement from soils and building materials into multi-level buildings with basements or crawl spaces. With the generalization, the model retains its original simplicity and ease of use. The model calculates radon entry rates that are consistent with measurements published for basement test structures at Colorado State University, confirming approximately equal contributions from diffusion and pressure-driven air flow at indoor-outdoor air pressure differences of deltaP(i-o) = -3.5 Pa. About one-fourth of the diffusive radon entry comes from concrete slabs and three-fourths comes from the surrounding soils. Calculated radon entry rates with and without a barrier over floor-wall shrinkage cracks generally agree with Colorado State University measurements when a sustained pressure of deltaP(i-o) = -2 Pa is used to represent calm wind (<1 m s(-1)) conditions. Calculated radon distributions in a 2-level house also are consistent with published measurements and equations.

  1. Simulation model of lung cancer incidence related to smoking and radon daughter exposure

    International Nuclear Information System (INIS)

    Stolowijk, J.A.J.

    1990-01-01

    A mathematical model of lung cancer and radon daughter exposure is presented. It is aimed to provide a quantitative estimate in the form of dose-effect relationship. The nature of the cigarette smoking and radon exposure interaction it is shown to be a multiplicative or sub-multiplicative function rather than a simpler model in which the effect of the two exposures would be summed. The model was written in the SAS programming language. An annotated listing of the program is given. 4 refs

  2. Modified technology in new constructions, and cost effective remedial action in existing structures, to prevent infiltration of soil gas carrying radon

    International Nuclear Information System (INIS)

    Ericson, S.O.; Schmied, H.; Clavensjoe, B.

    1984-01-01

    The general principles and mechanism of how soil gas infiltrates and carries radon from the foundation bed and subsoil into buildings are discussed. The Swedish Building Research Council has funded experiments and evaluation of cost effective remedial actions. The work has concerned existing dwellings with high concentration of radon, resulting from infiltrating soil gas and/or exhalation from building materials. A review and evaluation is given of experience and results acquired up to the summer of 1984. 100 dwellings have been constructed with consideration of possible infiltration of soil gas. In general minor modifications are sufficient to prevent infiltration. (Author)

  3. Lower radiation weighting factor for radon indicated in mechanistic modelling of human lung cancer

    International Nuclear Information System (INIS)

    Brugmans, M.J.P.; Leenhouts, H.P.

    2002-01-01

    A two-mutation carcinogenesis (TMC) model was fitted to the age-dependent lung cancer incidence in a cohort of Dutch Hodgkin patients treated with radiotherapy. Employing the results of previous TMC analyses of lung cancer due to smoking (by British doctors) and due to exposure to radon (for Colorado miners) a model fit was obtained with an estimate for the low LET radiation effect at the cellular level. This allows risk calculations for lung cancer from low LET radiation. The excess absolute risks are in tune with the values reported in the literature, the excess relative risks differ among the exposed groups. Comparing the cellular radiation coefficients for radon and for low LET radiation leads to an estimated radiation weighting factor for radon of 3 (0.1-6). (author)

  4. Acciones de rehabilitación frente a la entrada de gas radón Rehabilitation Measures against radon gas entry

    Directory of Open Access Journals (Sweden)

    Borja Frutos Vázquez

    2011-01-01

    Full Text Available El gas radón es un agente patológico para los usuarios de los edificios en donde se manifiesta su presencia. Por su origen, en la cadena de desintegración del uranio, conlleva efectos radiactivos que, en el organismo humano, determinan un aumento de riesgo en la generación de cáncer pulmonar. Procedente de suelos donde hay masas de granito u otros sustratos con contenidos de uranio, penetra a través de los materiales habitualmente usados en la construcción; como es el caso de las soleras de hormigón, muros de sótano, etc. Para impedir la inmisión de este gas en los espacios habitados, se pueden considerar varias actuaciones en edificios ya construidos. El objeto de este trabajo consiste en mostrar los resultados sobre reducciones de radón conseguidas por distintas soluciones constructivas que se han diseñado y ejecutado con el fin de frenar la inmisión de gas radón al interior de un prototipo de vivienda construido al efecto.Radon gas is a pathological agent for inhabitants of buildings where it is present. Due to its origin in uranium decay chain, it bears radioactive effects that inside human body lead to higher risks of developing lung cancer. It comes from soils containing granite masses or other substrates containing uranium. It enters through common material used in constructions, such as concrete ground slabs, basement walls, etc. In order to avoid such gas immission into inhabited rooms, several measurements cab be considered for existing buildings. This study intends to show the results obtained for radon reductions by means of different constructive solutions, already designed and executed so as to stop radon gas immission into a prototype building constructed for this specific purpose.

  5. The use of radon (Rn-222) and volatile organic compounds in monitoring soil gas to localize NAPL contamination at a gas station in Rio Claro, São Paulo State, Brazil

    International Nuclear Information System (INIS)

    Barbosa, E.Q.; Galhardi, J.A.; Bonotto, D.M.

    2014-01-01

    This study focuses on the presence of radon ( 222 Rn) and volatile organic compounds (VOCs) in soil gases at a gas station located in the city of Rio Claro, São Paulo, Brazil, where a fossil fuel leak occurred. The spatial distribution results show a correlation between 222 Rn and VOCs, consistent with the fact that radon gas has a greater chemical affinity with organic phases than with water. This finding demonstrates that the presence of a residual hydrocarbon phase in an aquifer can retain radon, leading to a reduced radon content in the soil gas. The data in this study confirm the results of previous investigations, in which the method used in this study provided a preliminary fingerprint of a contaminated area. Furthermore, the data analysis time is brief, and only simple equipment is required. - Highlights: • 222 Rn in soil gases. • Correlation between 222 Rn and VOCs. • Useful method as a preliminary fingerprint of a contaminated area

  6. Doses to LiF :Ti, Mg chips encapsulated in plastic extremity rings as a result of radon gas exposure

    International Nuclear Information System (INIS)

    Kearfott, Kimberlee J; Noon, Evan P; Rafique, Muhammad

    2015-01-01

    Previous studies measured the effects of 222 Rn on various thermoluminescent dosemeters (TLDs). This study quantified the effects of 222 Rn on LiF : Ti,Mg chips encapsulated in plastic extremity rings. For 28 d, one batch of TLDs was left in a chamber with high radon levels, and another batch in a control chamber with normal background radon levels. A few TLDs in each batch were removed from the rings for direct exposure to the ambient air in each chamber. Passive continuous radon monitors (CRMs) recorded the 222 Rn levels. TLDs were processed using a third-party dosimetry company, CRM data were analysed, and the relationship between integrated 222 Rn concentration and TLD response was determined. The batch of TLDs in the experimental chamber showed a weak response to 222 Rn gas, which was in the order of 0.5 nSv Bq −1  m 3  d −1 . (paper)

  7. A model to predict radon exhalation from walls to indoor air based on the exhalation from building material samples

    International Nuclear Information System (INIS)

    Sahoo, B.K.; Sapra, B.K.; Gaware, J.J.; Kanse, S.D.; Mayya, Y.S.

    2011-01-01

    In recognition of the fact that building materials are an important source of indoor radon, second only to soil, surface radon exhalation fluxes have been extensively measured from the samples of these materials. Based on this flux data, several researchers have attempted to predict the inhalation dose attributable to radon emitted from walls and ceilings made up of these materials. However, an important aspect not considered in this methodology is the enhancement of the radon flux from the wall or the ceiling constructed using the same building material. This enhancement occurs mainly because of the change in the radon diffusion process from the former to the latter configuration. To predict the true radon flux from the wall based on the flux data of building material samples, we now propose a semi-empirical model involving radon diffusion length and the physical dimensions of the samples as well as wall thickness as other input parameters. This model has been established by statistically fitting the ratio of the solution to radon diffusion equations for the cases of three-dimensional cuboidal shaped building materials (such as brick, concrete block) and one dimensional wall system to a simple mathematical function. The model predictions have been validated against the measurements made at a new construction site. This model provides an alternative tool (substitute to conventional 1-D model) to estimate radon flux from a wall without relying on 226 Ra content, radon emanation factor and bulk density of the samples. Moreover, it may be very useful in the context of developing building codes for radon regulation in new buildings. - Research highlights: → A model is proposed to predict radon flux from wall using flux of building material. → It is established based on the diffusion mechanism in building material and wall. → Study showed a large difference in radon flux from building material and wall. → Model has been validated against the measurements made at

  8. Airflow and radon transport modeling in four large buildings

    International Nuclear Information System (INIS)

    Fan, J.B.; Persily, A.K.

    1995-01-01

    Computer simulations of multizone airflow and contaminant transport were performed in four large buildings using the program CONTAM88. This paper describes the physical characteristics of the buildings and their idealizations as multizone building airflow systems. These buildings include a twelve-story multifamily residential building, a five-story mechanically ventilated office building with an atrium, a seven-story mechanically ventilated office building with an underground parking garage, and a one-story school building. The air change rates and interzonal airflows of these buildings are predicted for a range of wind speeds, indoor-outdoor temperature differences, and percentages of outdoor air intake in the supply air Simulations of radon transport were also performed in the buildings to investigate the effects of indoor-outdoor temperature difference and wind speed on indoor radon concentrations

  9. Indoor radon concentration and outdoor/indoor pressure difference correlation

    International Nuclear Information System (INIS)

    Cechak, T.; Fronka, A.; Moucka, L.

    2004-01-01

    In the current approach to the radon issue, the radon risk for people living in a building is estimated based on the average indoor radon concentration. Short-term measurements as usually applied fail to reflect the wide range of radon variations arising from ventilation, radon supply and, in particular, human activities in the building. For this reason, efforts are made to find a new approach to the assessment of the quality of a building as a radon barrier, independent of the weather conditions and residential habits. A simple model of radon volume activity entering the building at a constant rate and simultaneously ventilated at a constant rate is applicable to this task. The rate of radon ingress can be regarded as a parameter making it possible to quantify the leakage of structures provided the barrier against the radon in a soil gas. The ventilation rate, on the other hand, characterizes the leakage of the whole building envelope at a given outdoor/indoor pressure difference. A unique measuring technique called the blower door exists whereby a defined pressure difference between the indoor and outdoor atmosphere can be established. Under such conditions both the ventilation rate and the rate of radon ingress can be measured and expressed as a function of the pressure difference. An analysis of the model of a room with a constant ventilation and constant radon supply is presented and the relationship between radon supply and ventilation rate can be assumed. Some experimental results show how the model can be utilized. The real indoor-outdoor air pressure differences, the indoor-soil air pressure differences, and some effects of different ventilation regimes are given. Other experiments, which have been done by using the blower door method, illustrate the possible effects and some restrictions for a routine application are discussed

  10. Modified technology in new constructions, and cost effective remedial action in existing structures, to prevent infiltration of soil gas carrying radon

    International Nuclear Information System (INIS)

    Ericson, S.O.; Schmid, H.; Clavensjo, B.

    1984-01-01

    The general principles and mechanisms of how soil gas carrying radon infiltrates from the foundation bed and subsoil into buildings are discussed. The Swedish Building Research Council has funded experiments and evaluations of cost effective remedial actions. The work has concerned existing dwellings with high concentration of radon where this is a result of infiltrating soil gas and/or exhalation from building materials. A review is given of experience and results acquired up to the summer of 1983. 100 dwellings have been erected with consideration of possible infiltration of soil gas. Modification of design, added costs (investment and operation) and resulting concentration of radon in indoor air is discussed. In general minor modifications are sufficient. (author)

  11. Radon Gas Concentration Measurement In Soil For Some Holy Positions In Al-Najaf Al-Ashraf Governorate

    International Nuclear Information System (INIS)

    Hasan, K.H.; Hussain, H.H.

    2014-01-01

    In this search we measurement Radon gas concentration in the soil of holy positions in Al-Najaf Al-Ashraf city.We choice it for honorable position in all the world and, because millions of peoples and religious sciences students visit it.we selected 23 positions .By using a short-term way in modern technology its (RAD7) to measured concentration for depths (10,30,50,70)cm in all the holy positions.All the concentration in position studies within the range allowed of the global

  12. The radon gas at the context of legislation on the quality of internal air in buildings - the Portuguese experience

    International Nuclear Information System (INIS)

    Pinto, Paulo G.A.N.; Pereira, Alcides J.S.C.; Neves, Luis J.P.F.

    2011-01-01

    Radon gas has been recognized as an important environmental risk factor, especially when found in high concentrations inside buildings, and is currently classified by the World Health Organization as a carcinogen type 1. In this context, there is legislation in Portugal since 2006 that sets limits to its concentration in indoor air. The aim of this work was to synthesize the existing legislation with focus on the sampling and analysis. Some statistical data about the measurements obtained in the Natural Radioactivity Laboratory, of the Department of Earth Sciences, of the University of Coimbra are presented, and discussed in the context of the National Energy Certification of Buildings System

  13. Radon activities in natural gases

    International Nuclear Information System (INIS)

    Sajo, B.L.; Palfalvi, J.

    1995-01-01

    Radon activities have been measured in gas samples used for residential heading, in Venezuela and in Hungary. Gas bottles were selected randomly in different regions, and radon activities were monitored with ionization clambers and solid stoke track detections. Radon concentrations in household natural gas are presented for regions in Venezuela and in Budapest, Hungary. The latter was found to be in the range of 88-135 Bq/m 3 . (R.P.)

  14. Swiss radon programme 'RAPROS'

    International Nuclear Information System (INIS)

    Zeller, W.

    1992-03-01

    The results of the five-year radon research program RAPROS presented in this report, allow for scientifically valid statements on the origin of elevated levels of indoor radon in Switzerland. These results form a basis for recommendations and for actions to be taken. Indoor radon concentrations have been measured in more than 4000 living-rooms and 2000 basements; a sampling density of about 0.2% of the Swiss housing stock. According to these measurements radon leads to an estimated average annual effective dose of 2 milli-Sievert, although in some regions the annual dose may be much higher. Extrapolation of the existing data shows that in about 10'000 Swiss houses radon may exceed 1000 Bq/m 3 . For these houses remedial actions are recommended. There seems to be no radon problem in the large cities in the Swiss Plateau. High indoor radon concentrations in Switzerland are due to the soil beneath the buildings. Data from the study indicated that the most important soil characteristic influencing indoor radon concentrations was its gas permeability. Because natural ventilation in a heated house creates a slight underpressure in the lower levels with respect to surrounding soils, radon is driven from the soil into the building. Weatherization of the houses to reduce energy consumption had in most cases no effect on the indoor radon concentrations. Radon from tap water or from building materials does not contribute significantly to indoor radon levels in Switzerland. The high levels in the Jura Mountains are thought to be associated with karstic limestone bedrock. Several houses within Switzerland have now been modified to reduce radon levels. The most successful mitigation technique combined forced-air ventilation with tightening of the basement to decrease or prevent air infiltration from the soil. (author) figs., tabs., refs

  15. Temperature calibration formula for activated charcoal radon collectors

    International Nuclear Information System (INIS)

    Cooper, Alexandre; Le, Thiem Ngoc; Iimoto, Takeshi; Kosako, Toshiso

    2011-01-01

    Radon adsorption by activated charcoal collectors such as PicoRad radon detectors is known to be largely affected by temperature and relative humidity. Quantitative models are, however, still needed for accurate radon estimation in a variable environment. Here we introduce a temperature calibration formula based on the gas adsorption theory to evaluate the radon concentration in air from the average temperature, collection time, and liquid scintillation count rate. On the basis of calibration experiments done by using the 25 m 3 radon chamber available at the National Institute of Radiological Sciences in Japan, we found that the radon adsorption efficiency may vary up to a factor of two for temperatures typical of indoor conditions. We expect our results to be useful for establishing standardized protocols for optimized radon assessment in dwellings and workplaces. - Research highlights: → The temperature effect on radon adsorption is proportional to αe β/T . → The calibration formula is CF(T,t)=3.1x10 -5 e (2887)/((T+273)) [1-e -0.080t ]. → The radon adsorption efficiency varies up to a factor of two for T = 8.5-31 o C. → The average temperature is suitable for estimating CF(T,t) in a fluctuating environment.

  16. Temperature calibration formula for activated charcoal radon collectors

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Alexandre, E-mail: alexandre.cooper@gmail.co [Graduate School of Engineering, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Le, Thiem Ngoc [Institute of Nuclear Science and Technology, Vietnam Atomic Energy Commission, 59 Ly Thuong Kiet, Hanoi (Viet Nam); Iimoto, Takeshi; Kosako, Toshiso [Graduate School of Engineering, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan)

    2011-01-15

    Radon adsorption by activated charcoal collectors such as PicoRad radon detectors is known to be largely affected by temperature and relative humidity. Quantitative models are, however, still needed for accurate radon estimation in a variable environment. Here we introduce a temperature calibration formula based on the gas adsorption theory to evaluate the radon concentration in air from the average temperature, collection time, and liquid scintillation count rate. On the basis of calibration experiments done by using the 25 m{sup 3} radon chamber available at the National Institute of Radiological Sciences in Japan, we found that the radon adsorption efficiency may vary up to a factor of two for temperatures typical of indoor conditions. We expect our results to be useful for establishing standardized protocols for optimized radon assessment in dwellings and workplaces. - Research highlights: {yields} The temperature effect on radon adsorption is proportional to {alpha}e{sup {beta}/T}. {yields} The calibration formula is CF(T,t)=3.1x10{sup -5}e{sup (2887)/((T+273))} [1-e{sup -0.080t}]. {yields} The radon adsorption efficiency varies up to a factor of two for T = 8.5-31 {sup o}C. {yields} The average temperature is suitable for estimating CF(T,t) in a fluctuating environment.

  17. Modelling uncertainties in the diffusion-advection equation for radon transport in soil using interval arithmetic.

    Science.gov (United States)

    Chakraverty, S; Sahoo, B K; Rao, T D; Karunakar, P; Sapra, B K

    2018-02-01

    Modelling radon transport in the earth crust is a useful tool to investigate the changes in the geo-physical processes prior to earthquake event. Radon transport is modeled generally through the deterministic advection-diffusion equation. However, in order to determine the magnitudes of parameters governing these processes from experimental measurements, it is necessary to investigate the role of uncertainties in these parameters. Present paper investigates this aspect by combining the concept of interval uncertainties in transport parameters such as soil diffusivity, advection velocity etc, occurring in the radon transport equation as applied to soil matrix. The predictions made with interval arithmetic have been compared and discussed with the results of classical deterministic model. The practical applicability of the model is demonstrated through a case study involving radon flux measurements at the soil surface with an accumulator deployed in steady-state mode. It is possible to detect the presence of very low levels of advection processes by applying uncertainty bounds on the variations in the observed concentration data in the accumulator. The results are further discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Study on calculation models and distribution rules of the radon concentration and its progenies concentration in blind roadway with forced-exhaust ventilation

    International Nuclear Information System (INIS)

    Ye Yongjun; Wang Liheng; Zhou Xinghuo; Li Xiangyang; Zhong Yongming; Wang Shuyun; Ding Dexin

    2014-01-01

    The forced-exhaust ventilation is an important way to control the concentration of radon and its progenies in long-distance blind driving roadway. It is of great significance for guiding the design of ventilation and radiation protection to study distribution characteristics of the concentration of radon and its progenies in the wind of roadway adopting the forced-exhaust ventilation. Therefore, according to the decay relationship of radon and its progenies, a simplified mathematical calculation model was built, which relates to the radon activity concentration and the potential alpha concentration of radon progenies. The paper also analyzed the sources of radon and its progenies in the limited space of the blind roadway. Then, based on the turbulence mass transfer theory of ventilation air flow, the paper established mathematical calculation models of distribution characteristics of the radon activity concentration and the potential alpha concentration of radon progenies in blind roadway with forced-exhaust ventilation, respectively. Finally, the paper applied the calculation models to a special blind roadway, and discussed the influence of the ventilation air inflow and the radon exhalation rate of rock wall on the distribution of radon concentration and the potential alpha concentration of radon progenies in the roadway. Meanwhile, some protective measurements were put forward to reduce the radiation dose of worker caused by radon and its progenies in the blind roadway. (authors)

  19. Wind-induced contaminant transport in near-surface soils with application to radon entry into buildings

    Energy Technology Data Exchange (ETDEWEB)

    Riley, William Jowett [Univ. of California, Berkeley, CA (United States)

    1996-05-01

    Indoor air exposures to gaseous contaminants originating in soil can cause large human health risks. To predict and control these exposures, the mechanisms that affect vapor transport in near-surface soils need to be understood. In particular, radon exposure is a concern since average indoor radon concentrations lead to much higher risks than are generally accepted for exposure to other environmental contaminants. This dissertation examines an important component of the indoor radon problem: the impacts of wind on soil-gas and radon transport and entry into buildings. The research includes experimental and modeling studies of wind`s interactions with a building`s superstructure and the resulting soil-gas and radon flows in the surrounding soil. In addition to exploring the effects of steady winds, a novel modeling technique is developed to examine the impacts of fluctuating winds on soil-gas and radon transport.

  20. Wind-induced contaminant transport in near-surface soils with application to radon entry into buildings

    International Nuclear Information System (INIS)

    Riley, W.J.

    1996-05-01

    Indoor air exposures to gaseous contaminants originating in soil can cause large human health risks. To predict and control these exposures, the mechanisms that affect vapor transport in near-surface soils need to be understood. In particular, radon exposure is a concern since average indoor radon concentrations lead to much higher risks than are generally accepted for exposure to other environmental contaminants. This dissertation examines an important component of the indoor radon problem: the impacts of wind on soil-gas and radon transport and entry into buildings. The research includes experimental and modeling studies of wind's interactions with a building's superstructure and the resulting soil-gas and radon flows in the surrounding soil. In addition to exploring the effects of steady winds, a novel modeling technique is developed to examine the impacts of fluctuating winds on soil-gas and radon transport

  1. Control of indoor radon and radon progeny concentrations

    International Nuclear Information System (INIS)

    Sextro, R.G.

    1985-05-01

    There are three general categories of techniques for the control of radon and radon progeny concentrations in indoor air - restriction of radon entry, reduction of indoor radon concentrations by ventilation or air cleaning, and removal of airborne radon progeny. The predominant radon entry process in most residences appears to be pressure driven flow of soil gas through cracks or other openings in the basement, slab, or subfloor. Sealing these openings or ventilation of the subslab or subfloor space are methods of reducing radon entry rates. Indoor radon concentrations may be reduced by increased ventilation. The use of charcoal filters for removal of radon gas in the indoor air by adsorption has also been proposed. Concentrations of radon progeny, which are responsible for most of the health risks associated with radon exposures, can be controlled by use of electrostatic or mechanical filtration. Air circulation can also reduce radon progeny concentrations in certain cases. This paper reviews the application and limitations of each of these control measures and discusses recent experimental results

  2. Generation and mobility of radon in soil

    International Nuclear Information System (INIS)

    1992-01-01

    Objectives of this research include: (1) To determine the processes that cause large seasonal and short-term changes in the radon (Rn) content of soil gases, and to develop methods of predicting and modeling these variations; (2) to evaluate the relation of Rn emanation coefficients to form of radium (Ra) and other U-series decay products, particularly the role of Ra in organic matter and Fe-oxides; (3) to evaluate the conditions in which convection of gas in soil and bedrock may affect soil gas radon availability in houses; and, (4) to collaborate with other DOE researchers on evaluation of Rn flux into houses, using our well characterized soil sites

  3. Study of radon and thoron gas behaviour in the air at the commercial centers in Rio de Janeiro and Pocos de Caldas city

    International Nuclear Information System (INIS)

    Castro, Carlos A.C.; Cardoso, Domingos D.

    2005-01-01

    The radon is a radioactive gas. It occurs naturally in the atmosphere coming from the decay of radium, with emission of alpha particles. There are three radon isotopes more known, of which the most important under the environmental point of view is the Rn-222, whose half life is 3.82 days. The radon and their descendants are responsible by more than 40 % of the natural radioactive dose received for the human beings inside the building. In doses above 4 pCi/l, given as occupational dose, can cause among other diseases, the lung cancer. The main source of radon inside the building is the soil. The incidence of radon inside the building varies according to the soil composition, the materials employed in its construction, the inside air temperature and humidity, time during the day, season and the ventilation process designed. The work was realized at the commercial centers in Rio de Janeiro and Pocos de Caldas, for methodology confirmation. It was utilized the passive (track detectors) and active (two filters technique. Kusnetz technique, Tsivoglou technique and alpha spectrometry technique) methods. The objective of this work was to analyze the radon and thoron concentrations levels in order to supply parameters upon the quality of the air in those commercial centers. (author)

  4. Radiological risk assessment of environmental radon

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, Norafatin; Majid, Amran Ab; Yahaya, Redzuwan; Yasir, Muhammad Samudi [Nuclear Science Programme, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2013-11-27

    Measurements of radon gas ({sup 222}Rn) in the environmental are important to assess indoor air quality and to study the potential risk to human health. Generally known that exposure to radon is considered the second leading cause of lung cancer after smoking. The environmental radon concentration depends on the {sup 226}Ra concentration, indoor atmosphere, cracking on rocks and building materials. This study was carried out to determine the indoor radon concentration from selected samples of tin tailings (amang) and building materials in an airtight sealed homemade radon chamber. The radiological risk assessment for radon gas was also calculated based on the annual exposure dose, effective dose equivalent, radon exhalation rates and fatal cancer risk. The continuous radon monitor Sun Nuclear model 1029 was used to measure the radon concentration emanates from selected samples for 96 hours. Five types of tin tailings collected from Kampar, Perak and four samples of building materials commonly used in Malaysia dwellings or building constructions were analysed for radon concentration. The indoor radon concentration determined in ilmenite, monazite, struverite, xenotime and zircon samples varies from 219.6 ± 76.8 Bq m{sup −3} to 571.1 ± 251.4 Bq m{sup −3}, 101.0 ± 41.0 Bq m{sup −3} to 245.3 ± 100.2 Bq m{sup −3}, 53.1 ± 7.5 Bq m{sup −3} to 181.8 ± 9.7 Bq m{sup −3}, 256.1 ± 59.3 Bq m{sup −3} to 652.2 ± 222.2 Bq m{sup −3} and 164.5 ± 75.9 Bq m{sup −3} to 653.3 ± 240.0 Bq m{sup −3}, respectively. Whereas, in the building materials, the radon concentration from cement brick, red-clay brick, gravel aggregate and cement showed 396.3 ± 194.3 Bq m{sup −3}, 192.1 ± 75.4 Bq m{sup −3}, 176.1 ± 85.9 Bq m{sup −3} and 28.4 ± 5.7 Bq m{sup −3}, respectively. The radon concentration in tin tailings and building materials were found to be much higher in xenotime and cement brick samples than others. All samples in tin tailings were exceeded the

  5. Influence of ventilation strategies on indoor radon concentrations based on a semiempirical model for Florida-style houses

    International Nuclear Information System (INIS)

    Hintenlang, D.E.; Al-Ahmady, K.K.

    1994-01-01

    Measurements in a full-scale experimental facility are used to benchmark a semiempirical model for predicting indoor radon concentrations for Florida-style houses built using slab-on-grade construction. The model is developed to provide time-averaged indoor radon concentrations from quantitative relationships between the time-dependent radon entry and elimination mechanisms that have been demonstrated to be important for this style of residential construction. The model successfully predicts indoor radon concentrations in the research structure for several pressure and ventilation conditions. Parametric studies using the model illustrate how different ventilation strategies affect indoor radon concentrations. It is demonstrated that increasing house ventilation rates by increasing the effective leakage area of the house shell does not reduce indoor radon concentrations as effectively as increasing house ventilation rates by controlled duct ventilation associated with the heating, ventilating, and air conditioning system. The latter strategy provides the potential to minimize indoor radon concentrations while providing positive control over the quality of infiltration air. 9 refs., 5 figs

  6. Radon - natural health threat

    International Nuclear Information System (INIS)

    Wrixon, Anthony

    1985-01-01

    Natural sources of radiation attract little attention, yet a survey has found radon gas in buildings at levels which put the occupants at some risk. The author wants safety standards set without undue delay. (author)

  7. Daily changes of radon concentration in soil gas under influence of atmospheric factors: room temperature, soil surface temperature and relative humidity

    Energy Technology Data Exchange (ETDEWEB)

    Lara, Evelise G.; Oliveira, Arno Heeren de, E-mail: evelise.lara@gmail.com, E-mail: heeren@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Rocha, Zildete; Rios, Francisco Javier, E-mail: rochaz@cdtn.br, E-mail: javier@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    This work aims at relating the daily change in the radon concentration in soil gas in a Red Yellow Acrisol (SiBCS) under influence of atmospheric factors: room temperature, soil surface temperature and relative humidity. The {sup 226}Ra, {sup 232}Th, U content and permeability were also performed. The measurements of radon soil gas were carried out by using an AlphaGUARD monitor. The {sup 226}Ra activity concentration was made by Gamma Spectrometry (HPGe); the permeability was carried out using the RADON-JOK permeameter and ICP-MS analysis to {sup 232}Th and U content. The soil permeability is 5.0 x 10{sup -12}, which is considered average. The {sup 226}Ra (22.2 ± 0.3 Bq.m{sup -3}); U content (73.4 ± 3.6 Bq.kg{sup -1}) and {sup 232}Th content (55.3 ± 4.0 Bq.kg{sup -1}) were considered above of average concentrations, according to mean values for soils typical (~ 35.0 Bq.kg{sup -1}) by UNSCEAR. The results showed a difference of 26.0% between the highest and the lowest concentration of radon in soil gas: at midnight (15.5 ± 1.0 kBq.m{sup -3}) and 3:00 pm, the highest mean radon concentration (21.0 ± 1.0 kBq.m{sup -3}). The room temperature and surface soil temperature showed equivalent behavior and the surface soil temperature slightly below room temperature during the entire monitoring time. Nevertheless, the relative humidity showed the highest cyclical behavior, showing a higher relationship with the radon concentration in soil gas. (author)

  8. Daily changes of radon concentration in soil gas under influence of atmospheric factors: room temperature, soil surface temperature and relative humidity

    International Nuclear Information System (INIS)

    Lara, Evelise G.; Oliveira, Arno Heeren de

    2015-01-01

    This work aims at relating the daily change in the radon concentration in soil gas in a Red Yellow Acrisol (SiBCS) under influence of atmospheric factors: room temperature, soil surface temperature and relative humidity. The 226 Ra, 232 Th, U content and permeability were also performed. The measurements of radon soil gas were carried out by using an AlphaGUARD monitor. The 226 Ra activity concentration was made by Gamma Spectrometry (HPGe); the permeability was carried out using the RADON-JOK permeameter and ICP-MS analysis to 232 Th and U content. The soil permeability is 5.0 x 10 -12 , which is considered average. The 226 Ra (22.2 ± 0.3 Bq.m -3 ); U content (73.4 ± 3.6 Bq.kg -1 ) and 232 Th content (55.3 ± 4.0 Bq.kg -1 ) were considered above of average concentrations, according to mean values for soils typical (~ 35.0 Bq.kg -1 ) by UNSCEAR. The results showed a difference of 26.0% between the highest and the lowest concentration of radon in soil gas: at midnight (15.5 ± 1.0 kBq.m -3 ) and 3:00 pm, the highest mean radon concentration (21.0 ± 1.0 kBq.m -3 ). The room temperature and surface soil temperature showed equivalent behavior and the surface soil temperature slightly below room temperature during the entire monitoring time. Nevertheless, the relative humidity showed the highest cyclical behavior, showing a higher relationship with the radon concentration in soil gas. (author)

  9. Seasonal and spatial variations in Rn-222 and Rn-220 in soil gas, and implications for indoor radon levels

    International Nuclear Information System (INIS)

    Sharman, G.

    1992-01-01

    Rn-222 enters dwellings as a component of soil gas drawn from the soil by mass flow driven by the pressure difference between the house and soil beneath. In a site on Northampton Sand Ironstone (Aalenian), a preferred path of emanation (hotspot) was found. A difference of 63 Bq L -1 Rn-222 was recorded in July between this point and another 3 m away. Rn-222 in this hotspot shows 12% less variation annually than the surrounding rock. During winter, Rn-222 values within 1.6 m of the house were 44% lower than those at more than 4 m away. Rn-222 showed a 99.5% negative correlation with wind run, showing that on this soil wind pressure can significantly reduce radon in the soil at 500 mm depth. Rn-220 in soil gas correlated positively at the 99.5% level with grass and air temperatures. Rn-220 was not associated with the hotspot. (Author)

  10. A Radon Chamber without Radium Source for Detector Calibration and Radon Measurements

    International Nuclear Information System (INIS)

    Al-Azmi, D.; Karunakara, N.

    2008-01-01

    A radon chamber of volume 216 liters was designed and constructed for calibration of radon detectors and radon test measurements. The main feature of this chamber is that the active 226 Ra source, to generate the 222 Rn inside the chamber volume, is not required. Instead, 222 Rn from soil gas is utilized for this purpose. The supply of radon comes from the soil gas. Soil gas is drawn from the soil to fill the chamber with high radon concentration levels (∼ 80 kBq/m3). Desired radon concentration levels can be obtained by drawing the soil gas for different time durations and/or flow rate (author)

  11. Radon flux maps for the Netherlands and Europe using terrestrial gamma radiation derived from soil radionuclides

    NARCIS (Netherlands)

    Manohar, S.N.; Meijer, H.A.J.; Herber, M.A.

    2013-01-01

    Naturally occurring radioactive noble gas, radon (Rn-222) is a valuable tracer to study atmospheric processes and to validate global chemical transport models. However, the use of radon as a proxy in atmospheric and climate research is limited by the uncertainties in the magnitude and distribution

  12. Models for comparing lung-cancer risks in radon- and plutonium-exposed experimental animals

    International Nuclear Information System (INIS)

    Gilbert, E.S.; Cross, F.T.; Sanders, C.L.; Dagle, G.E.

    1990-10-01

    Epidemiologic studies of radon-exposed underground miners have provided the primary basis for estimating human lung-cancer risks resulting from radon exposure. These studies are sometimes used to estimate lung-cancer risks resulting from exposure to other alpha- emitters as well. The latter use, often referred to as the dosimetric approach, is based on the assumption that a specified dose to the lung produces the same lung-tumor risk regardless of the substance producing the dose. At Pacific Northwest Laboratory, experiments have been conducted in which laboratory rodents have been given inhalation exposures to radon and to plutonium ( 239 PuO 2 ). These experiments offer a unique opportunity to compare risks, and thus to investigate the validity of the dosimetric approach. This comparison is made most effectively by modeling the age-specific risk as a function of dose in a way that is comparable to analyses of human data. Such modeling requires assumptions about whether tumors are the cause of death or whether they are found incidental to death from other causes. Results based on the assumption that tumors are fatal indicate that the radon and plutonium dose-response curves differ, with a linear function providing a good description of the radon data, and a pure quadratic function providing a good description of the plutonium data. However, results based on the assumption that tumors are incidental to death indicate that the dose-response curves for the two exposures are very similar, and thus support the dosimetric approach. 14 refs., 2 figs., 6 tabs

  13. Environmental radon

    International Nuclear Information System (INIS)

    Majumdar, S.K.; Schmalz, R.F.; Miller, E.W.

    1990-01-01

    This book covers many aspects of environmental radon, including: historical perspectives; occurrence and properties; detection, measurement, and mitigation, radon and health; and political, economic, and legislative impacts

  14. Dosimetry of inhaled radon and thoron progeny

    International Nuclear Information System (INIS)

    James, A.C.

    1994-06-01

    This chapter reviews recent developments in modeling doses received by lung tissues, with particular emphasis on application of ICRP's new dosimetric model of the respiratory tract for extrapolating to other environments the established risks from exposure to radon progeny in underground mines. Factors discussed include: (1) the influence of physical characteristics of radon progeny aerosols on dose per unit exposure, e.g., the unattached fraction, and the activity-size distributions of clustered and attached progeny; (2) the dependence of dose on breathing rate, and on the exposed subject (man, woman or child); (3) the variability of dose per unit exposure in a home when exposure is expressed in terms of potential α energy or radon gas concentration; (4) the comparative dosimetry of thoron progeny; and (5) the effects of air-cleaning on lung dose. Also discussed is the apparent discrepancy between lung cancer risk estimates derived purely from dosimetry and the lung cancer incidence observed in the epidemiological studies of radon-exposed underground miners. Application of ICRP's recommended risk factors appears to overestimate radon lung-cancer risk for miners by a factor of three. ''Normalization'' of the calculated effective dose is therefore needed, at least for α dose from radon and thoron progeny, in order to obtain a realistic estimate of lung cancer risk

  15. Toward resolving model-measurement discrepancies of radon entry into houses

    International Nuclear Information System (INIS)

    Garbesi, K.

    1993-01-01

    My dissertation research investigated the source of the model-measurement discrepancy via carefully controlled field experiments conducted at an experimental basement located in natural soil in Ben Lomond, California. Early experiments at the structure (Chapter II) confirmed the existence and magnitude of the model-measurement discrepancy, ensuring that it was not merely an artifact of inherently complex and poorly understood field sites. The measured soil-gas entry rate during structure depressurization was found to be an order of magnitude larger than predicted by a current three-dimensional numerical model of radon transport. The exact magnitude of the discrepancy depends on whether the arithmetic or geometric mean of the small-scale measurements of permeability is used to estimate the effective permeability of the soil. This factor is a critical empirical input to the model and was determined for the Ben Lomond site in the typical fashion using single-probe static depressurization measurement at multiple locations. The remainder of the dissertation research tests a hypothesis to explain the observed discrepancy: that soil permeability assessed using relatively small-scale probe measurements (0.1-0.5 m) does not reflect bulk soil permeability for flows that is likely to occur at larger scales of several meters or more in real houses and in the test structure. The idea is that soil heterogeneity is of a nature that, as flows occur over larger scales, larger scales of heterogeneity are encountered that facilitate larger flux rates, resulting in a scale dependence of effective soil permeability. In Chapter III, I describe the development of a dual-probe dynamic pressure technique to measure soil permeability to air (and anisotropy of permeability) at various length scales. Preliminary field tests of the apparatus indicated that soil permeability was indeed scale dependent

  16. Inversion of the Jacobi-Porstendörfer Room Model for the Radon Progeny

    Czech Academy of Sciences Publication Activity Database

    Thomas, J.; Jílek, K.; Brabec, Marek

    2010-01-01

    Roč. 55, č. 4 (2010), s. 433-437 ISSN 0029-5922 Institutional research plan: CEZ:AV0Z10300504 Keywords : Jacobi room model * inversion and invariants of the model * unattached radon daughters * attachment rate * deposition rate Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.321, year: 2010 http://www.nukleonika.pl/www/back/full/vol55_2010/v55n4p433f.pdf

  17. The radon 222 transport in soils. The case of the storage of residues coming from uranium ores processing; La migration du radon 222 dans un sol. Application aux stockages de residus issus du traitement des minerais d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Ferry, C

    2000-07-01

    Uranium Mill Tailings (UMT) contain comparatively large quantities of radium-226. This radionuclide yields, by radioactive decay, the radioactive gas radon-222. Tailing piles are routinely covered to reduce the radon release-rate into the atmosphere. In order to assess the long term environmental impact of a UMT repository, mechanisms governing radon exhalation at the soil surface must be deciphered and understood. A model of radon transport in the unsaturated zone is developed for this purpose: water- and air-flow in the porous material are determined, as well as radon transport by diffusion in the pore space and advection by the gas phase. The radon transport model in the unsaturated zone - TRACI (which stands, in French, for Radon Transport within the Unsaturated Layer) - calculates moisture contents in the soil, Darcy's velocities of the liquid and gas phases, radon concentrations in the gas phase and radon flux at the soil surface. TRACI's results are compared with observations carried out on a UMT and a cover layer. Input parameters are derived from the textural analysis of the material under study, whereas upper boundary conditions are given by meteorological data. If we consider measurement errors and uncertainties on the porous medium characterisation, model's results are generally in good agreement with observations, at least on the long run. Moreover, data analysis shows hat transient phenomena are understood as well, in most situations. (author)

  18. Prediction of the net radon emission from a model open pit uranium mine

    International Nuclear Information System (INIS)

    Nielson, K.K.; Perkins, R.W.; Schwendiman, L.C.; Enderlin, W.I.

    1979-09-01

    Radon emission from a model open pit uranium mining operation has been estimated by applying radon exhalation fluxes measured in an open pit uranium mine to the various areas of the model mine. The model mine was defined by averaging uranium concentrations, mine dimensions, production and procedural statistics for eight major open pit uranium mines in the Casper, Wyoming area. The resulting emission rates were 630 Ci/RRY (1 RRY one = 1000-MW(e) reactor operating for 1 year) during mining operations and 26 Ci/RRY/y after abandoment of the mine assuming 100% recovery of U 3 O 8 from the ore, or 700 Ci/RRY and 29 Ci/RRY/y assuming 90.5% recovery

  19. Atmospheric radionuclide transport model with radon postprocessor and SBG module. Model description version 2.8.0; ARTM. Atmosphaerisches Radionuklid-Transport-Modell mit Radon Postprozessor und SBG-Modul. Modellbeschreibung zu Version 2.8.0

    Energy Technology Data Exchange (ETDEWEB)

    Richter, Cornelia; Sogalla, Martin; Thielen, Harald; Martens, Reinhard

    2015-04-20

    The study on the atmospheric radionuclide transport model with radon postprocessor and SBG module (model description version 2.8.0) covers the following issues: determination of emissions, radioactive decay, atmospheric dispersion calculation for radioactive gases, atmospheric dispersion calculation for radioactive dusts, determination of the gamma cloud radiation (gamma submersion), terrain roughness, effective source height, calculation area and model points, geographic reference systems and coordinate transformations, meteorological data, use of invalid meteorological data sets, consideration of statistical uncertainties, consideration of housings, consideration of bumpiness, consideration of terrain roughness, use of frequency distributions of the hourly dispersion situation, consideration of the vegetation period (summer), the radon post processor radon.exe, the SBG module, modeling of wind fields, shading settings.

  20. Revealing the hidden faults in the SE flank of Mt. Etna using radon in-soil gas measurement.

    Science.gov (United States)

    Johnová, K; Thinová, L; Giammanco, S

    2014-07-01

    Although there are many methods for investigating tectonic structures, many faults remain hidden, and they can endanger the life and property of people living along them. The slopes of volcanoes are covered with such hidden faults, near which strong earthquakes and gas releases can appear. Revealing hidden faults can therefore contribute significantly to the protection of people living in volcanic areas. In the study, seven different techniques were used for making measurements of in-soil radon concentrations in order to search for hidden faults on the SE flank of the Mt. Etna volcano. These reported methods had previously been proved to be useful tools for investigating fault structures. The main aim of the experiment presented here was to evaluate the usability of these methods in the geological conditions of the Mt. Etna region, and to find the best place for continual radon monitoring using a permanent station in the near future. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Lung cancer from radon and smoking: a multistage model for the WISMUT uranium miners

    International Nuclear Information System (INIS)

    Dillen, Teun van; Bijwaard, Harmen; Schnelzer, Maria; Kreuzer, Michaela; Grosche, Bernd

    2008-01-01

    Full text: In the world's third-largest uranium-mining province located in areas of Saxony and Thuringia in the former German Democratic Republic, the WISMUT Company conducted extensive uranium mining starting in 1946. Up to 1990, when mining activities were discontinued, most of the 400,000 employees had been exposed to uranium ore dust and radon and its progeny. It is well established that, besides smoking, such exposures are associated with an increased risk of lung cancer. From about 130,000 known miners a huge cohort of 59,000 miners has been formed and in an epidemiological analysis lung cancer risks have been evaluated (Grosche et al., 2006). We will present an alternative approach using a biologically-based multistage carcinogenesis model quantifying the lung-cancer risk related to both the exposure to radon and smoking habits. This mechanistic technique allows for extrapolation to the low exposures that are important for present-day radiation protection purposes and the transfer of risk across populations. The model is applied to a sub-cohort of about 35,000 persons who were employed at WISMUT after 1955, with known annual exposures estimated from the job-exposure matrix (Lehmann et al., 2004). Unfortunately, detailed information on smoking is missing for most miners. However, this information has been retrieved in two case-control studies, one of which was nested in the cohort while the other was not (Brueske-Hohlfeld et al., 2006). For these studies, the relevant smoking parameters are assembled in so-called smoking spectra that are next projected onto the entire cohort using a Monte-Carlo sampling method. Individual smoking habits that are randomly assigned to the cohort members, together with the information on annual exposure to radon, is used as an input for the multistage model. Model parameters related to radon and tobacco exposure are fitted with a maximum-likelihood technique. We will show results of the observed and expected lung

  2. Standardization of radon measurements

    International Nuclear Information System (INIS)

    Matuszek, J.M.; Hutchinson, J.A.; Lance, B.H.; Virgil, M.G.; Mahoney, R.J.

    1988-01-01

    Radon escaping from soil into homes appears to present the single greatest source of radiation exposure that most people will ever face. Measurement protocols for the relatively inert gas inextricably link the method of collection with the counting of the specimen. The most commonly used methods depend on the measurement of dislocation sites on plastic α-track detectors or on the adsorption of radon onto activated charcoal for subsequent counting of the γ-rays produced by decay of the radon progeny. The uncertainties inherent to the radon-measurement methods used commercially in the United States are far greater than those for measurements of other environmental radionuclides. The results of this preliminary study raise doubts as to whether existing proficiency-testing programs can provide assurance that radon-measurement methods are representative of actual conditions in any dwelling. 17 refs., 1 figs., 4 tabs

  3. Evaluation of the open vial method in the radon measurement; Evaluacion del metodo del vial abierto en la medicion de radon

    Energy Technology Data Exchange (ETDEWEB)

    Lopez del Rio, H.; Davila R, J. I.; Mireles G, F., E-mail: hlopezdelrio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-10-15

    The open vial method is a simple technique, under-utilized but that take advantage of the great radon solubility in organic solvents, therefore applies in the measurement of the radon concentration exhaled in soil. The method consists on the exposition to the gas radon of an open vial with scintillating solution. An integral mathematical model for indoors that describes the emanation processes and gas radon exhalation was developed, as well as the radon dissolution in the scintillation liquid, besides obtaining the characteristic parameters of the experimental system proposed for the radon concentration calculation exhaled by soils. Two experimental arrangements were designed with exposition cameras of 12 and 6 L and quantity of different soil. The open vial was prepared with a mixture of 8 ml of deionized water and 12 ml of scintillation liquid OptiPhase Hi Safe 3 in polyethylene vials; the measurements of the dissolved radon were carried out in scintillation liquid equipment. As a result, on average 2.0% of the exhaled radon is dissolved in the open vial and the dissolved fraction is independent of the experimental arrangement. Also was observed that the exposition time does not affect the radon dissolution significantly, in correspondence with the reported in the literature. (Author)

  4. The measure and control system of mini-type radon room based on PC104

    International Nuclear Information System (INIS)

    Zhou Shumin; East China Inst. of Technology, Fuzhou; Tang Bin; Sun Yamin

    2005-01-01

    Radon room is one of the standard equipment which demarcates radon measure instrument. The paper discusses the dynamic method and mathematic model which keeps the radon consistence stability in radon room. The system is developed on PC104. The system can monitor the radon consistence and replenishment radon according the radon control parameter. (authors)

  5. Radon-induced cancer: a cell-based model of tumorigenesis due to protracted exposures

    International Nuclear Information System (INIS)

    Elkind, M.M.

    1994-01-01

    In 1982, results with C3H mouse embryo cells showed that the frequency of neoplastic transformation was enhanced when exposures to fission-spectrum neutrons were protracted in time. This finding was unexpected because the opposite was found with low-LET radiations. Similar neutron enhancements were reported with normal life-span Syrian hamster embryo cells, and with human hybrid cells. Because other studies did not confirm the preceding, in 1990 - at a conference convened by the US Armed Forces Radiobiological Research Institute - a biophysical model was proposed to explain the basis for the enhancement observed in some experiments but not in others. The model attributed special sensitivities, related to killing and neoplastic transformation, to cells in and around mitosis. Subsequently, it was shown that late G 2 /M phase cells constituted this window of sensitivity. In the instance of tumorigenesis, the model predicted that protracted exposures to a high-LET radiation would result in enhanced frequencies of transformation providing that susceptible cells were cycling or could be induced to cycle. The model explained data on lung tumour induction in rats breathing radon at different concentrations, and uranium miners working in atmospheres containing different concentrations of radon. The model also explains the anomalous finding that lung cancer deaths are often sublinearly correlated with indoor radon concentration. (author)

  6. A study on the environmental behavior of global air pollutants based on the continuous measurements of atmospheric radon concentrations

    International Nuclear Information System (INIS)

    Iida, Takao; Yamazawa, Hiromi

    2003-01-01

    Radon is a useful natural radioactive tracer of air transportation of atmospheric pollution, since radon is a noble gas and chemically inert. The atmospheric radon concentration is usually measured by a high-sensitivity electrostatic collection method or a two-filter method. The variations of radon concentrations observed over a solitary island and in the upper atmosphere are suitable for comparing with those of air pollutants. Some numerical simulation models were used to study the radon global transport in the atmosphere. In East Asia, atmospheric radon and air pollutants are transported with the air stream from the continent of China to the Northwestern Pacific Ocean. It is necessary to clarify the transport mechanism from both radon observations at various locations and numerical simulation. (author)

  7. Predicting radon/radon daughter concentrations in underground mines

    International Nuclear Information System (INIS)

    Leach, V.A.

    1984-01-01

    A detailed description of a computer programme is outlined for the calculation of radon/radon daughter concentrations in air. This computer model is used to predict the radon/radon daughter concentrations in Working Level (WL) at the workplace and at the various junctions at either end of the branches in a typical ventilation network proposed for the Jabiluka mine in the Northern Territory

  8. Statistical aspects of autoregressive-moving average models in the assessment of radon mitigation

    International Nuclear Information System (INIS)

    Dunn, J.E.; Henschel, D.B.

    1989-01-01

    Radon values, as reflected by hourly scintillation counts, seem dominated by major, pseudo-periodic, random fluctuations. This methodological paper reports a moderate degree of success in modeling these data using relatively simple autoregressive-moving average models to assess the effectiveness of radon mitigation techniques in existing housing. While accounting for the natural correlation of successive observations, familiar summary statistics such as steady state estimates, standard errors, confidence limits, and tests of hypothesis are produced. The Box-Jenkins approach is used throughout. In particular, intervention analysis provides an objective means of assessing the effectiveness of an active mitigation measure, such as a fan off/on cycle. Occasionally, failure to declare a significant intervention has suggested a means of remedial action in the data collection procedure

  9. Assessment of radon exposure in Austria based on geology and settlement

    International Nuclear Information System (INIS)

    Gruber, Valeria; Seidel, Claudia

    2008-01-01

    In Austria a fundamental radon indoor data net (about 40 000 measurements) exists. These radon indoor data are standardized and provide averaged political communities' values. This data net should be enhanced by soil gas measurements with regard to geological conditions, to avoid averaging and influences by political boundaries. Different geological units (characterized by geology, geochemical conditions, mineralogy, geophysics) will be surveyed regarding radon concentration by soil gas measurements and estimated to their potential radon hazard. To assess the radon exposure of the population geological units are selected which are either existing settlement areas or potential ones. So this survey can also provide a basis for land use planning. In this paper results of first studies for this purpose are shown. 160 soil gas measurements were carried out in different soil and sediment deposits originating from different ice age glacier movements in the Alps. These deposits are popular settlement areas, and indoor radon levels of some 1000 Bq/l were detected. 50 % of the results of soil gas radon measurements were above 60 kBq/m 3 , 18 % above 120 kBq/m 3 , which is likely to exceed the indoor radon standard of 400 Bq/l according to the Austrian standard ONORM S 5280-2. Higher radon activity concentrations were found in older ice ages, because of further progressed weathering. The radon soil gas measurements were carried out in different seasons to verify seasonal variations, and other parameters like Ra-226, Ra-228 activity concentration in soils, radon emanation factor, soil permeability and soil moisture were determined and related to the radon activity concentration. According to the example of this study, further soil gas measurements will be carried out in selected geological units. Additional research on the impact of actual dwelling and inhabitation situation on public exposure due to radon in Austria is being done currently. The soil gas radon measurement data

  10. Radon Mapping of the Osijek Town

    International Nuclear Information System (INIS)

    Radolic, V.; Faj, Z.; Smit, G.; Culo, D.; Planinic, J.

    1998-01-01

    After ten years investigation of radon seasonal variations at three very different locations, as well as radon concentration measurements in kindergartens and schools, systematical indoor radon measurements were undertaken in dwellings of Osijek. Indoor radon was measured by means of the LR-115 nuclear track detector at 48 town locations that gave the arithmetic mean of 71.6 Bq m -3 , standard deviation of 44.0 Bq m -3 and geometric mean of 60.1 Bq m -3 , for the radon concentration range from 23 to 186 Bq m -3 . The empirical frequency distribution of radon concentrations, with the class width of 20 Bq m -3 , was in accordance with the theoretical log-normal distribution which was shown with χ 2 - test. The radon map pointed out a region of higher radon concentrations (central part of the town) that was ascribed to the geological soil structure. Thus supposition was confirmed by radon measurement in the soil gas using radon emanators with the LR-115 film that showed the positive correlation between radon concentrations in the soil and indoors. Radon measurements in Osijeks primary schools pointed out a school that had the highest radon concentration (300 Bq m -3 ) considering all the former indoor radon measurements. The radon distribution in the school building was investigated afterwards radon mitigation procedures were undertaken. (author)

  11. Radon: Gas transport in soils and its relation to radon availability: Hot spot identification and flow characteristics near structures. Progress report and request for third year incremental funding

    International Nuclear Information System (INIS)

    Reimer, G.M.

    1995-01-01

    There are 3 major objectives being addressed in this research. The first is to participate, by providing ground truth quality assurance, in the DOE/LBL/EPA cooperative study to determine a methodology to predict the areas where indoor radon concentrations have the highest probability of exceeding 20 pCi/L (750 Bq/m 3 ). The second is to examine 2 common types of homes (basement and non-basement) for radon entry by monitoring specific parameters under normal living conditions. The third task is to participate with other researchers in their studies using the techniques and experience developed by this principal investigator during previously funded times. Those researchers seek assistance in measuring soil permeability, determining the effect of meteorological parameters on radon entry, determining the diffusion characteristics of standard basement wall materials, developing a GIS (Geographic Information System) data base for predicting regional radon potential, and examining the contribution of regional solution-developed permeability in limestone to the radon potential of an area

  12. State-Space Dynamic Model for Estimation of Radon Entry Rate, based on Kalman Filtering

    Czech Academy of Sciences Publication Activity Database

    Brabec, Marek; Jílek, K.

    2007-01-01

    Roč. 98, - (2007), s. 285-297 ISSN 0265-931X Grant - others:GA SÚJB JC_11/2006 Institutional research plan: CEZ:AV0Z10300504 Keywords : air ventilation rate * radon entry rate * state-space modeling * extended Kalman filter * maximum likelihood estimation * prediction error decomposition Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.963, year: 2007

  13. Carbon dioxide-krypton separation and radon removal from nuclear-fuel-reprocessing off-gas streams

    International Nuclear Information System (INIS)

    Hirsch, P.M.; Higuchi, K.Y.; Abraham, L.

    1982-07-01

    General Atomic Company (GA) is conducting pilot-plant-scale tests that simulate the treatment of radioactive and other noxious volatile and gaseous constituents of off-gas streams from nuclear reprocessing plants. This paper reports the results of engineering-scale tests performed on the CO 2 /krypton separation and radon holdup/decay subsystems of the GA integrated off-gas treatment system. Separation of CO 2 from krypton-containing gas streams is necessary to facilitate subsequent waste processing and krypton storage. Molecular sieve 5A achieved this separation in dissolver off-gas streams containing relatively low krypton and CO 2 concentrations and in krypton-rich product streams from processes such as the krypton absorption in liquid carbon dioxide (KALC) process. The CO 2 /krypton separation unit is a 30.5-cm-diameter x 1.8-m-long column containing molecular sieve 5A. The loading capacity for CO 2 was determined for gas mixtures containing 250 ppM to 2.2% CO 2 and 170 to 750 ppM krypton in either N 2 or air. Gas streams rich in CO 2 were diluted with N 2 to reduce the temperature rise from the heat of adsorption, which would otherwise affect loading capacity. The effluent CO 2 concentration prior to breakthrough was less than 10 ppM, and the adsorption capacity for krypton was negligible. Krypton was monitored on-line with a time-of-flight mass spectrometer and its concentration determined quantitatively by a method of continuous analysis, i.e., selected-ion monitoring. Radon-220 was treated by holdup and decay on a column of synthetic H-mordenite. The Rn-220 concentration was monitored on-line with flow-through diffused-junction alpha detectors. Single-channel analyzers were utilized to isolate the 6.287-MeV alpha energy band characteristic of Rn-220 decay from energy bands due to daughter products

  14. Blower door method in radon diagnostics

    International Nuclear Information System (INIS)

    Fronka, A.; Moucka, L.

    2004-01-01

    The idea of the radon transfer factor is commonly presented as the ratio of the building indoor radon concentration to the subsoil radon concentration. Ventilation and the pressure field over the whole building envelope, which varies in a time over a very wide range even in the same building, poses a major problem. Therefore a new approach based on the controlled conditions determining the soil air infiltration was developed. Radon in soil gas infiltrates into the building indoor environment particularly through cracks and other leakages in the structure providing the building contact with its subsoil. The infiltration is driven by the air pressure difference on the two sides of the structure. The pressure difference is caused by the stack effect and its value ranges from 1-2 Pa in family houses to some tens of Pa in higher buildings. Unfortunately, the pressure difference is very unstable under normal conditions, being affected by a host of parameters such as the height of the building, distribution and geometry of leakages, outdoor-indoor temperature difference, etc. Wind direction and velocity of the wind plays a major role. In our research the blower door method was applied in combination with a monitoring of the indoor radon concentration. The indoor-outdoor pressure difference and the pressure difference at the two sides of the screen shutter of the blower door fan are also measured. The blower door ensures a constant, evaluable air exchange rate. The fan power is regulated to provide a stable pressure difference within the range of roughly 5-100 Pa. This approach provides very well defined conditions allowing us to apply a constant ventilation-constant radon supply model. In such circumstances the dynamical changes of radon concentrations are very fast, and therefore a unique continual radon monitor was applied. The radon supply rate is evaluated from the radon steady state of the time course of radon concentration. The dependence of the radon supply rate on

  15. Radon in Antarctica

    International Nuclear Information System (INIS)

    Ilic, R.; Rusov, V.D.; Pavlovych, V.N.; Vaschenko, V.M.; Hanzic, L.; Bondarchuk, Y.A.

    2005-01-01

    The paper reviews results of radon measurements obtained in Antarctic research stations in the last 40 years by both active and passive radon monitors. A brief description of the radon laboratory set-up in the Ukrainian Academician Vernadsky station on the Antarctic Peninsula (W 64 o 16 ' , S 65 o 15 ' ), where radon is measured by two types of etched track Rn dosimeter and 4 types of continuous radon monitoring devices is presented. Some selected results of research work are described related to: (i) analysis of radon storms, defined as an abrupt increase of 222 Rn during the occurrence of a cyclone, and its applicability for the study of the transport of air masses of continental origin to Antarctica; (ii) a study of the correlation of changes of radon concentration and geomagnetic field induced by tectonic activity and its application to predicting tectonomagnetic anomalies, and (iii) verification of a newly developed theoretical model based on noise analysis of the measured radon signal for earthquake prediction. Suggestions for future utilization of radon for basic research in Antarctica (and not only in Antarctica) conclude the contribution. conclude the contribution

  16. Measurements of indoor radon and radon progeny in Mexico City

    International Nuclear Information System (INIS)

    Cheng, Y.S.; Rodriguez, G.P.

    1996-01-01

    Indoor radon has been a public concern associated with increased lung cancer risks. Radon decay products interact with indoor aerosols to form progeny with different size distributions, which may influence the lung dosimetry when the progeny are inhaled. Air pollution in Mexico City is a serious problems with high particulate concentrations, but there are few reports of indoor radon measurement. The purposes of this study were to measure the aerosol concentration, radon concentration, and radon activity size distribution in the living area of three houses in Mexico City. The radon concentration was monitored by a RGM-3 radon gas monitor (Eberline, Inc., Santa Fe, NM). A graded diffusion battery was used to determine the progeny concentration and activity size distribution. The concentration and size distribution of the indoor aerosols were monitored by a quartz, crystal microbalance cascade impactor. Our measurements showed high concentrations of indoor aerosols (20-180 gg m -3 ). However, the radon concentrations-were low ( -1 ), but showed a clear diurnal pattern with peak concentrations from 2-10 AM. The activity size distributions of radon progeny were trimodal, with peaks of 0.6 nm, 4-5 nm, and 100 rim. Most activities were associated with large particle sizes. Our results indicated that indoor radon concentration was not high, due in part to a relatively high air exchange with outdoor air. The high aerosol concentration may also play an important part in the activity size distribution of radon progeny

  17. Effective diffusion coefficient of radon in concrete, theory and method for field measurements

    International Nuclear Information System (INIS)

    Culot, M.V.J.; Olson, H.G.; Schiager, K.J.

    1976-01-01

    A linear diffusion model serves as the basis for determination of an effective radon diffusion coefficient in concrete. The coefficient was needed to later allow quantitative prediction of radon accumulation within and behind concrete walls after application of an impervious radon barrier. A resolution of certain discrepancies noted in the literature in the use of an effective diffusion coefficient to model diffusion of a radioactive gas through a porous medium is suggested. An outline of factors expected to affect the concrete physical structure and the effective diffusion coefficient of radon through it is also presented. Finally, a field method for evaluating effective radon diffusion coefficients in concrete is proposed and results of measurements performed on a concrete foundation wall are compared with similar published values of gas diffusion coefficients in concrete. (author)

  18. Determining Radium-226 concentration from Radon-222 emanation in building materials: a theoretical model

    International Nuclear Information System (INIS)

    Barreto, Rafael C.; Perna, Allan F.N.; Narloch, Danielle C.; Del Claro, Flavia; Correa, Janine N.; Paschuk, Sergei A.

    2017-01-01

    It was developed an improved theoretical model capable to estimate the radium concentration in building materials solely measuring the radon-222 concentration in a con ned atmosphere. This non-destructive technique is not limited by the size of the samples, and it intrinsically includes back diffusion. The resulting equation provides the exact solution for the concentration of radon-222 as a function of time and distance in one dimension. The effective concentration of radium-226 is a fit parameter of this equation. In order to reduce its complexity, this equation was simplified considering two cases: low diffusion in the building material compared to the air, and a building material initially saturated with radon-222. These simplified versions of the exact one dimension solution were used to t experimental data. Radon-222 concentration was continuously measured for twelve days with an AlphaGUARD TM detector, located at the Laboratory of Applied Nuclear Physics at Universidade Tecnologica Federal do Parana (UTFPR). This model was applied to two different materials: cement mortar and concrete, which results were respectively (15:7 ±8:3) Bq=kg and (10:5±2:4) Bq=kg for the radium-226 effective concentration. This estimation was confronted with the direct measurements of radium in the same materials (same sources) using gamma-ray spectrometry, fulfilled at Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), which results were respectively (13:81±0:23) Bq=kg and (12:61±0:22) Bq=kg. (author)

  19. Determining Radium-226 concentration from Radon-222 emanation in building materials: a theoretical model

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Rafael C.; Perna, Allan F.N.; Narloch, Danielle C.; Del Claro, Flavia; Correa, Janine N.; Paschuk, Sergei A., E-mail: baarreth@gmail.com, E-mail: allan_perna@hotmail.com, E-mail: daninarloch@hotmail.com, E-mail: aviadelclaro@gmail.com, E-mail: janine_nicolosi@hotmail.com, E-mail: spaschuk@gmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil). Departamento Academico de Fisica e Departamento Academico de Construcao Civil

    2017-07-01

    It was developed an improved theoretical model capable to estimate the radium concentration in building materials solely measuring the radon-222 concentration in a con ned atmosphere. This non-destructive technique is not limited by the size of the samples, and it intrinsically includes back diffusion. The resulting equation provides the exact solution for the concentration of radon-222 as a function of time and distance in one dimension. The effective concentration of radium-226 is a fit parameter of this equation. In order to reduce its complexity, this equation was simplified considering two cases: low diffusion in the building material compared to the air, and a building material initially saturated with radon-222. These simplified versions of the exact one dimension solution were used to t experimental data. Radon-222 concentration was continuously measured for twelve days with an AlphaGUARD{sup TM} detector, located at the Laboratory of Applied Nuclear Physics at Universidade Tecnologica Federal do Parana (UTFPR). This model was applied to two different materials: cement mortar and concrete, which results were respectively (15:7 ±8:3) Bq=kg and (10:5±2:4) Bq=kg for the radium-226 effective concentration. This estimation was confronted with the direct measurements of radium in the same materials (same sources) using gamma-ray spectrometry, fulfilled at Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), which results were respectively (13:81±0:23) Bq=kg and (12:61±0:22) Bq=kg. (author)

  20. Sensitivity analysis of the noble gas transport and fate model: CASCADR9

    International Nuclear Information System (INIS)

    Lindstrom, F.T.; Cawlfield, D.E.; Barker, L.E.

    1994-03-01

    CASCADR9 is a desert alluvial soil site-specific noble gas transport and fate model. Input parameters for CASCADR9 are: man-made source term, background concentration of radionuclides, radon half-life, soil porosity, period of barometric pressure wave, amplitude of barometric pressure wave, and effective eddy diffusivity. Using average flux, total flow, and radon concentration at the 40 day mark as output parameters, a sensitivity analysis for CASCADR9 is carried out, under a variety of scenarios. For each scenario, the parameter to which output parameters are most sensitive are identified

  1. Radon as geological tracer

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, T.; Anjos, R.M. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Fisica; Valladares, D.L.; Rizzotto, M.; Velasco, H.; Ayub, J. Juri [Universidad Nacional de San Luis (Argentina). Inst. de Matematica Aplicada San Luis (IMASL); Silva, A.A.R. da; Yoshimura, E.M. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2012-07-01

    Full text: This work presents measurements of {sup 222}Rn levels performed in La Carolina gold mine and Los Condores tungsten mine at the province of San Luis, Argentina, today used for tourist visitation, and can evaluate the potential use of such radioactive noble gas as tracer or marker for geological processes in underground environments. By concentrations of {sup 40}K, {sup 232}Th and {sup 23}'8U were also measured in the walls of tunnels were determined the rocks mineral composition, what indicated that the mines have the same composition. In this sense, we used nuclear trace plastic detectors CR-39, gamma spectrometry of rock samples and Geiger-Muller (GM) monitors The patterns of radon gas transportation processes revealed that La Carolina could be interpreted through a model based on a radioactive gas confined into a single entrance tube, with constant cross section and air velocity. Los Condores, which has a second main entrance, could be interpreted through a model based on a radioactive gas confined into a two entrance tube, allowing a chimney effect for air circulation. The results showed the high potential of using {sup 222}Rn as a geological tracer. In what concerns the occupational hazard, in summer (time of more intense tourist activity in the mine) La Carolina presented a mean concentration of the radioactive noble gas that exceeds in four times the action level of 1,5 kBq m{sup -3} recommended by the International Commission of Radiological Protection (ICRP). The chimney effect shows the low mean concentration of radon in Los Condores. (author)

  2. Radon as geological tracer

    International Nuclear Information System (INIS)

    Lacerda, T.; Anjos, R.M.; Silva, A.A.R. da; Yoshimura, E.M.

    2012-01-01

    Full text: This work presents measurements of 222 Rn levels performed in La Carolina gold mine and Los Condores tungsten mine at the province of San Luis, Argentina, today used for tourist visitation, and can evaluate the potential use of such radioactive noble gas as tracer or marker for geological processes in underground environments. By concentrations of 40 K, 232 Th and 23 '8U were also measured in the walls of tunnels were determined the rocks mineral composition, what indicated that the mines have the same composition. In this sense, we used nuclear trace plastic detectors CR-39, gamma spectrometry of rock samples and Geiger-Muller (GM) monitors The patterns of radon gas transportation processes revealed that La Carolina could be interpreted through a model based on a radioactive gas confined into a single entrance tube, with constant cross section and air velocity. Los Condores, which has a second main entrance, could be interpreted through a model based on a radioactive gas confined into a two entrance tube, allowing a chimney effect for air circulation. The results showed the high potential of using 222 Rn as a geological tracer. In what concerns the occupational hazard, in summer (time of more intense tourist activity in the mine) La Carolina presented a mean concentration of the radioactive noble gas that exceeds in four times the action level of 1,5 kBq m -3 recommended by the International Commission of Radiological Protection (ICRP). The chimney effect shows the low mean concentration of radon in Los Condores. (author)

  3. Radon-Instrumentation; Radon-Instrumentacion

    Energy Technology Data Exchange (ETDEWEB)

    Moreno y Moreno, A. [Departamento de Apoyo en Ciencias Aplicadas, Benemerita Universidad Autonoma de Puebla, 4 Sur 104, Centro Historico 72000 Puebla (Mexico)

    2003-07-01

    The presentation of the active and passive methods for radon, their identification and measure, instrumentation and characteristics are the objectives of this work. Active detectors: Active Alpha Cam Continuous Air Monitor, Model 758 of Victoreen, Model CMR-510 Continuous Radon Monitor of the Signature Femto-Tech. Passive detectors: SSNTD track detectors in solids Measurement Using Charcoal Canisters, disk of activated coal deposited in a metallic box Electrets Methodology. (Author)

  4. Radon in Schools

    Science.gov (United States)

    ... Search Search Radon Contact Us Share Radon in Schools Related Information Managing Radon in Schools Radon Measurement ... Radon Could Be a Serious Threat to Your School Chances are you've already heard of radon - ...

  5. Geostatistical simulations for radon indoor with a nested model including the housing factor

    International Nuclear Information System (INIS)

    Cafaro, C.; Giovani, C.; Garavaglia, M.

    2016-01-01

    The radon prone areas definition is matter of many researches in radioecology, since radon is considered a leading cause of lung tumours, therefore the authorities ask for support to develop an appropriate sanitary prevention strategy. In this paper, we use geostatistical tools to elaborate a definition accounting for some of the available information about the dwellings. Co-kriging is the proper interpolator used in geostatistics to refine the predictions by using external covariates. In advance, co-kriging is not guaranteed to improve significantly the results obtained by applying the common lognormal kriging. Here, instead, such multivariate approach leads to reduce the cross-validation residual variance to an extent which is deemed as satisfying. Furthermore, with the application of Monte Carlo simulations, the paradigm provides a more conservative radon prone areas definition than the one previously made by lognormal kriging. - Highlights: • The housing class is inserted into co-kriging via an indicator function. • Inserting the housing classes in a co-kriging improves predictions. • The housing class has a structured component in space. • A nested model is implemented into the multigaussian algorithm. • A collection of risk maps is merged into one to create RPA.

  6. Geographical information system for radon gas from soil measurement; Il sistema informativo territoriale per la valutazione del potenziale di esalazione di radon dal suolo

    Energy Technology Data Exchange (ETDEWEB)

    Orlando, P.; Amici, M.; Altieri, A.; Massari, P.; Miccadei, E.; Onofri, A.; Orlando, C.; Paolelli, C.; Paron, P.; Perticaroli, P.; Piacentini, T.; Silvestri, C. [Milan Univ. Sacro Cuore, Milan (Italy). Servizio Centralizzato Radioisotopi; Belli, M.; Marchetti, A.; Petrocchi, A.; Rosamilia, S.; Serva, L.; Singh, G.; Tommasino, L. [Agenzia Nazionale per la Protezione dell' Ambiente, Rome (Italy); Minach, L.; Verdi, L. [Agenzia Provinciale per la Protezione dell' Ambiente, Bolzano (Italy); Bertolo, A.; Trotti, F. [Agenzia Regionale per la Protezione dell' Ambiente, Regione Veneto (Italy)

    2000-07-01

    The working program foresees the realization of an geographical information system for the check in field of the geological parameters and determination of uranium and radium contents in various type of rocks. It is here also pointed out a measuring method for radon concentration in soil. [Italian] In questo documento viene presentato il lavoro svolto fino ad oggi: dalla definizione dei parametri geologici ritenuti piu' significativi per la presenza di radon nel suolo e dalle misure in campo e in laboratorio, fino alla realizzazione del Sistema Informativo Territoriale (SIT) per la gestione dei suddetti parametri. Nel primo capitolo sono descritte le caratteristiche del radon, dal punto di vista chimico-fisico e geologico, per introdurre i criteri adottati nella scelta dei paramentri geologici e del loro peso per la valutazione del PERS (Potenziale di Esalazione Radon dal Suolo). Il secondo capitolo descrive il progetto in generale, mentre i successivi capitoli descrivono piu' in dettaglio la parte informatica e quella delle indagini sperimentali.

  7. Nanodosimetry and nanodosimetric-based models of radiation action for radon alpha particles

    International Nuclear Information System (INIS)

    1992-01-01

    The objective of our research work is to provide -- with the aid of biophysical models of radiation action -- information on human risks following exposure to radon alpha particles. The approach proposed consists of (1) developing appropriate models (parametric and non-parametric) for alpha radiation induction of relevant end points (survival, cellular transformation), (2) providing an accurate physical characterization of the particle tracks in terms of nanodosimetric distributions, (3) supporting the models by detailed, molecular studies of the direct and indirect effects of alpha particles on DNA. Activities in the second year of this project are described

  8. Detailed analysis of radon flux studies at Australian uranium projects

    International Nuclear Information System (INIS)

    Mudd, Gavin M.

    2005-01-01

    The release of radon gas and radon progeny from uranium projects is a major issue during operation as well as for the design of rehabilitation works. In Australia, there have been a number of premining radon flux studies as part of the environmental investigation and potential development of recent uranium projects. There is also an increasing amount of operational data on radon fluxes and loads from various aspects of projects, such as tailings, waste rock and mills. Thus there exists much useful measured data which can be used to assess the design radon flux and load targets for rehabilitation. The main projects for which radon data exists includes Ranger, Olympic Dam, Beverley, Honeymoon, Jabiluka, Yeelirrie, Lake Way, Koongarra, Moline, Coronation Hill, Rockhole, Nabarlek, Rum Jungle, Port Pirie and Ben Lomond. To date, much of this data has not been systematically evaluated. The need to compile and assess this data is twofold. Firstly, to assess the loads released from uranium production as an input into life-cycle analyses of the nuclear fuel cycle, such as those undertaken by UNSCEAR and industry groups. Secondly, there is a need to set suitable design standards for radon flux for the rehabilitation of former and current uranium projects. This paper will present such a detailed compilation of radon fluxes and loads which can then be used as the basis for both life-cycle analyses as well as setting appropriate site-specific rehabilitation criteria for radon. The implications for former and current projects is then discussed as well as future data needs. Ultimately, there is a critical need for thorough baseline surveys prior to mining to ensure accurate assessments of changes to radon fluxes and loads. The data and analysis presented is considered applicable to all uranium projects in Australia, as well as being a useful model for considering such issues internationally

  9. Parameters that characterize the radon hazard of soils

    International Nuclear Information System (INIS)

    Blue, T.E.; Mervis, J.A.; Jarzemba, M.S.; Carey, W.E.

    1990-01-01

    It has been observed that the radon concentration in homes does not depend solely on the steady-state 222 Rn concentration in the soil. An explanation for the lack of correlation between radon concentrations in the soil and in adjacent homes includes factors such as the construction of the homes, their heating systems, and the habits of their occupants. Another explanation, which is proposed in this paper, is that the steady-state concentration of radon in the pore gas does not fully characterize the soil as a radon hazard. Other soil properties, such as its diffusion length for radon and its porosity, may be important. In this paper, the authors have identified the soil properties important in radon transport into the basement of a home by mathematically modeling ventilated basement air enclosed in basement walls and surrounded by soil and by solving the model equations to determine an expression for the basement air radon concentration as a function of the properties of the soil and basement wall

  10. Health effects of radon

    International Nuclear Information System (INIS)

    Easterly, C.

    1994-01-01

    Exposure of people to radon has taken on increased interest during the last decade because of the understanding that buildings can serve to trap radon and its daughters, and thereby build up undesirable concentrations of these radioactive elements. Numerous studies of underground miners (often uranium miners) have shown an increased risk of lung cancer in comparison with nonexposed populations. Laboratory animals exposed to radon daughters also develop lung cancer. The abundant epidemiological and experimental data have established the carcinogenicity of radon progeny. Those observations are of considerable importance, because uranium, from which radon and its progeny arise, is ubiquitous in the earth's crust, including coal mines. Risk estimates of the health effects of long-term exposures at relatively low levels require continued development, especially to address the potential health effects of radon and radon daughters in homes and occupational settings where the exposure levels are less than levels in underground uranium and other metal mines that have been the subject of epidemiological studies. Two approaches can be used to characterize the lung-cancer risks associated with radon-daughter exposure: mathematical representations of the respiratory tract that model radiation doses to target cells and epidemiological investigation of exposed populations, mainly underground uranium miners. The mathematically-based dosimetric approach provides an estimate of lung cancer risk related to radon-daughter exposure based specifically on modeling of the dose to target cells. The various dosimetric models all require assumptions, some of which are not subject to direct verification, as to breathing rates; the deposition of radon daughters in the respiratory tract; and the type, nature, and location of the target cells for cancer induction. The most recent large committee effort drawn together to evaluate this issue was sponsored by the National Research Council

  11. Compact detector for radon and radon daughter products

    International Nuclear Information System (INIS)

    Alter, H.W.; Oswald, R.A.

    1986-01-01

    This invention provides an improved compact track registration detector for radon gas. The detector comprises a housing having an open mouth, a bottom, and side walls; track registration means, supported inside the housing, which forms damage tracks along paths traversed by alpha particles; a microporous filter positioned across the mouth of the housing to prevent entry of radon daughters and particulate matter; and a cap that may be placed on the mouth of the housing to retain the filter. The housing has internal wall surfaces dimensioned to optimize the registration of alpha particles from radon and radon daughters present in the housing

  12. Radon flux maps for the Netherlands and Europe using terrestrial gamma radiation derived from soil radionuclides

    Science.gov (United States)

    Manohar, S. N.; Meijer, H. A. J.; Herber, M. A.

    2013-12-01

    Naturally occurring radioactive noble gas, radon (222Rn) is a valuable tracer to study atmospheric processes and to validate global chemical transport models. However, the use of radon as a proxy in atmospheric and climate research is limited by the uncertainties in the magnitude and distribution of the radon flux density over the Earth's surface. Terrestrial gamma radiation is a useful proxy for generating radon flux maps. A previously reported radon flux map of Europe used terrestrial gamma radiation extracted from automated radiation monitoring networks. This approach failed to account for the influence of local artificial radiation sources around the detector, leading to under/over estimation of the reported radon flux values at different locations. We present an alternative approach based on soil radionuclides which enables us to generate accurate radon flux maps with good confidence. Firstly, we present a detailed comparison between the terrestrial gamma radiation obtained from the National Radiation Monitoring network of the Netherlands and the terrestrial gamma radiation calculated from soil radionuclides. Extending further, we generated radon flux maps of the Netherlands and Europe using our proposed approach. The modelled flux values for the Netherlands agree reasonably well with the two observed direct radon flux measurements (within 2σ level). On the European scale, we find that the observed radon flux values are higher than our modelled values and we introduce a correction factor to account for this difference. Our approach discussed in this paper enables us to develop reliable and accurate radon flux maps in countries with little or no information on radon flux values.

  13. Fluid-based radon mitigation technology development for industrial applications

    International Nuclear Information System (INIS)

    Liu, K.V.; Gabor, J.D.; Holtz, R.E.; Gross, K.C.

    1996-01-01

    The objective of the radon mitigation technology development effort is to develop an efficient and economical radon gas removal technology based on a fluid absorption process. The technology must be capable of cleaning up a wide range of radon gas stream concentrations to a level that meets EPA gas emission standards for residential and industrial applications. Argonne has recently identified a phenomenon that offers the possibility of radon recovery from the atmosphere with high efficiency at room temperature, and radon release at slightly elevated temperatures (50-60 degrees C.) such a device would offer numerous substantial advantages over conventional cryogenic charcoal systems for the removal of radon. Controlled sources of radon in Argonne's radon research facility are being used to quantitatively assess the performance of a selected class of absorbing fluids over a range of radon concentrations. This paper will discuss the design of laboratory- and engineering-scale radon absorption units and present some preliminary experimental test results

  14. Interaction of radon and smoking among Czech uranium miners using model of a threshold energy

    International Nuclear Information System (INIS)

    Boehm, R.; Holy, K.; Sedlak, A.

    2014-01-01

    Exposure to radon and smoking are among the most important factors influencing the risk of lung cancer. However, the joint effect of radon and smoking has not been sufficiently investigated so far. In this paper we will try to describe by means of a threshold energy model the mechanism of synergic effect of the aforementioned factors, and compare their influence on the risk of lung cancer. The model is based on the assumption that the inactivation of cells is caused by the excess of threshold specific energy z0 in the sensitive volume of the cell. Cigarette smoking causes, among others, an increase in the synthesis of the survivin protein that protects cells from apoptosis and thereby reduces their radiosensitivity. Survivin is therefore responsible for the increase of threshold energy z0, which in turn leads to the increase of lung cancer risk. A linear relationship between the threshold energy and the number of cigarettes smoked was assumed. The effect of smoking on radon exposure was evaluated for various groups of smokers that were defined by the degree of morphometric and geometric changes in the lungs induced by smoking and various degrees of chronic obstructive pulmonary disease. We simulate various scenarios of irradiation - short-term exposure, long-term exposure, as well as various smoking habits - smoker, ex-smoker. The calculated values can be, to an extent, compared to the epidemiological analysis geometric mixture models of Tomasek, who statistically evaluated epidemiological data about lung cancer occurrence among miners working in Jachymov and Pribram mines. From the results it follows that the correlation coefficient was particularly high. Although the approach outlined in this paper is only one of the many that strive to describe in detail the synergic effect of smoking and exposition, the used model can contribute to a more precise estimate of lung cancer risk in areas with various smoking habits. (authors)

  15. Radon-induced lung cancer in smokers and non-smokers: risk implications using a two-mutation carcinogenesis model

    International Nuclear Information System (INIS)

    Leenhouts, H.P.

    1999-01-01

    Three sets of data (population statistics in non-smokers, data from an investigation of the smoking habits of British doctors and a study of Colorado uranium miners) were used to analyse lung cancer in humans as a function of exposure to radon and smoking. One of the aims was to derive implications for radon risk estimates. The data were analysed using a two-mutation radiation carcinogenesis model and a stepwise determination of the model parameters. The basic model parameters for lung cancer were derived from the age dependence fit of the spontaneous lung cancer incidence in non-smokers. The effect of smoking was described by two additional parameters and, subsequently, the effect of radon by three other parameters; these five parameters define the dependence of the two mutation steps on smoking and exposure to radon. Using this approach, a consistent fit and comprehensive description of the three sets of data have been achieved, and the parameters could, at least partly, be related to cellular radiobiological data. The model results explain the different effect of radon on non-smokers and smokers as seen in epidemiological data. Although the analysis was only applied to a limited number of populations, lung cancer incidence as a result of radon exposure is estimated to be about ten times higher for people exposed at the age of about 15 than at about 50, although this effect is masked (especially for smokers) by the high lung cancer incidence from smoking. Using the model to calculate the lung cancer risks from lifetime exposure to radon, as is the case for indoor radon, higher risks were estimated than previously derived from epidemiological studies of the miners' data. The excess absolute risk per unit exposure of radon is about 1.7 times higher for smokers of 30 cigarettes per day than for non-smokers, even though, as a result of the low spontaneous tumour incidence in the non-smokers, the excess relative risk per unit exposure for the smokers is about 20 times

  16. Paloma-radon: Atmospheric radon-222 as a geochemical probe for water in the Martian subsoil.

    Science.gov (United States)

    Sabroux, J.-C.; Michielsen, N.; Voisin, V.; Ferry, C.; Richon, P.; Pineau, J.-F.; Le Roulley, J.-C.; Chassefière, E.

    2003-04-01

    Radon exhalation from a porous soil is known to depend strongly on the soil moisture content: a minute amount of water, or water ice, in the pore space increases dramatically the possibility for radon to migrate far from its parent mineral. We propose to take advantage of this characteristic by using atmospheric radon-222 as a geochemical probe for water in the Martian soil, at least one order of magnitude deeper than the current Mars Odyssey neutron data. Strong thermal inversions during the Martian night will accumulate radon in the lowest atmospheric boundary layer, up to measurable levels despite the comparatively high environmental (cosmic and solar) background radiation and the assumed low uranium content of the upper crust of the planet. Preliminary studies and development of an instrument for the measurement of the Martian atmospheric alpha radioactivity is part of the CNES-supported PALOMA experiment. Two test benches have been implemented, one of them allowing differential measurements of the diffusion of radon in the Martian soil simulant NASA JSC Mars-1, under relevant temperatures and pressures. The other, a 1 m^3 radon-dedicated test bench, aims to characterize the instrument that will measure radon in the Mars environment (7 mb CO_2). Tests on several nuclear radiation detectors show that semiconductor alpha-particle detectors (PIPS) are the best option (already on board the Mars Pathfinder Rover and other platforms). In addition, the detection volume is left open in order to capitalize upon the long (ca. 4 m) alpha track at this low pressure. A stationary diffusion model was developed in order to assess the radon flux at the Mars soil surface. Diffusion of gas in Martian soil is governed by Knudsen diffusion. The radon Knudsen diffusion coefficient was estimated, depending on the soil moisture and relevant structural properties, leading to a radon diffusion length of the order of 20 m. The landed platform PALOMA-Radon instrument will consist of a

  17. Paloma-radon: atmospheric radon 222 as a geochemical probe for water in the martian subsoil

    International Nuclear Information System (INIS)

    Sabroux, J.Ch.; Michielsen, N.; Voisin, V.

    2003-01-01

    Radon exhalation from a porous soil is known to depend strongly on the soil moisture content: a minute amount of water, or water ice, in the pore space increases dramatically the possibility for radon to migrate far from its parent mineral. We propose to take advantage of this characteristic by using atmospheric radon 222 as a geochemical probe for water in the Martian soil, at least one order of magnitude deeper than the current Mars Odyssey neutron data. Strong thermal inversions during the Martian night will accumulate radon in the lowest atmospheric boundary layer, up to measurable levels despite the comparatively high environmental (cosmic and solar) background radiation and the assumed low uranium content of the upper crust of the planet. Preliminary studies and development of an instrument for the measurement of the Martian atmospheric alpha radioactivity is part of the CNES supported PALOMA experiment. Two test benches have been implemented, one of them allowing differential measurements of the diffusion of radon in the Martian soil simulant NASA JSC Mars-1, under relevant temperatures and pressures. The other, a 1 m3 radon-dedicated test bench, aims to characterize the instrument that will measure radon in the Mars environment (7 mb CO 2 ). Tests on several nuclear radiation detectors show that semiconductor alpha-particle detectors (PIPS) are the best option. In addition, the detection volume is left open in order to capitalize upon the long (ca. 4 m) alpha track at this low pressure. A stationary diffusion model was developed in order to assess the radon flux at the Mars soil surface. Diffusion of gas in Martian soil is governed by Knudsen diffusion. The radon Knudsen diffusion coefficient was estimated, depending on the soil moisture and relevant structural properties, leading to a radon diffusion length of the order of 20 m. The landed platform PALOMA-Radon instrument will consist of a set of alpha detectors connected to an electronic spectrometer, a

  18. Paloma-radon: atmospheric radon 222 as a geochemical probe for water in the martian subsoil

    Energy Technology Data Exchange (ETDEWEB)

    Sabroux, J.Ch.; Michielsen, N.; Voisin, V

    2003-07-01

    Radon exhalation from a porous soil is known to depend strongly on the soil moisture content: a minute amount of water, or water ice, in the pore space increases dramatically the possibility for radon to migrate far from its parent mineral. We propose to take advantage of this characteristic by using atmospheric radon 222 as a geochemical probe for water in the Martian soil, at least one order of magnitude deeper than the current Mars Odyssey neutron data. Strong thermal inversions during the Martian night will accumulate radon in the lowest atmospheric boundary layer, up to measurable levels despite the comparatively high environmental (cosmic and solar) background radiation and the assumed low uranium content of the upper crust of the planet. Preliminary studies and development of an instrument for the measurement of the Martian atmospheric alpha radioactivity is part of the CNES supported PALOMA experiment. Two test benches have been implemented, one of them allowing differential measurements of the diffusion of radon in the Martian soil simulant NASA JSC Mars-1, under relevant temperatures and pressures. The other, a 1 m3 radon-dedicated test bench, aims to characterize the instrument that will measure radon in the Mars environment (7 mb CO{sub 2}). Tests on several nuclear radiation detectors show that semiconductor alpha-particle detectors (PIPS) are the best option. In addition, the detection volume is left open in order to capitalize upon the long (ca. 4 m) alpha track at this low pressure. A stationary diffusion model was developed in order to assess the radon flux at the Mars soil surface. Diffusion of gas in Martian soil is governed by Knudsen diffusion. The radon Knudsen diffusion coefficient was estimated, depending on the soil moisture and relevant structural properties, leading to a radon diffusion length of the order of 20 m. The landed platform PALOMA-Radon instrument will consist of a set of alpha detectors connected to an electronic spectrometer

  19. Radon Research Program, FY 1991

    International Nuclear Information System (INIS)

    1992-03-01

    The scientific information being sought in this program encompasses research designed to determine radon availability and transport outdoors, modeling transport into and within buildings, physics and chemistry of radon and radon progeny, dose response relationships, lung cancer risk, and mechanisms of radon carcinogenesis. The main goal of the DOE/OHER Radon Research Program is to develop information to reduce these uncertainties and thereby provide an improved health risk estimate of exposure to radon and its progeny as well as to provide information useful in radon control strategies. Results generated under the Program were highlighted in a National Research Council report on radon dosimetry. The study concluded that the risk of radon exposure is 30% less in homes than in mines. This program summary of book describes the OHER FY-1991 Radon Research Program. It is the fifth in an annual series of program books designed to provide scientific and research information to the public and to other government agencies on the DOE Radon Research Program

  20. Inversion of the Jacobi-Porstendorfer room model for the radon progeny

    International Nuclear Information System (INIS)

    Thomas, J.; Jilek, K.; Brabec, M.

    2010-01-01

    The Jacobi-Porstendoerfer (J-P) room model describes the behaviour of radon progeny in the atmosphere of a room. It distinguishes between free and attached radon progeny in air. It has been successfully used without substantial changes for nearly 40 years. There have been several attempts to invert the model approximately to determine the parameters describing the physical processes. Here, an exact solution is aimed at as an algebraic inversion of the system of six linear equations for the five unknown physical parameters k, X, R, q f , q a of the room model. Two strong linear dependencies in this system, unfortunately do not allow to obtain a general solution (especially not for the ventilation coefficient k), but only a parameterized one or for reduced sets of unknown parameters. More, the impossibility to eliminate one of the two linear dependencies and the departures of the measured concentrations forces to solve a set of allowed combinations of equations of the algebraic system and to accept its mean values (therefore with variances) as a result of the algebraic inversion. These results are in agreement with results of the least squares method as well as of a sophisticated modern statistical approach. The algebraic approach provides, of course, a lot of analytical relations to study the mutual dependencies between the model parameters and the measurable quantities. (authors)

  1. Radon transport model into a porous ground layer of finite capacity

    Science.gov (United States)

    Parovik, Roman

    2017-10-01

    The model of radon transfer is considered in a porous ground layer of finite power. With the help of the Laplace integral transformation, a numerical solution of this model is obtained which is based on the construction of a generalized quadrature formula of the highest degree of accuracy for the transition to the original - the function of solving this problem. The calculated curves are constructed and investigated depending on the diffusion and advection coefficients.The work was a mathematical model that describes the effect of the sliding attachment (stick-slip), taking into account hereditarity. This model can be regarded as a mechanical model of earthquake preparation. For such a model was proposed explicit finite- difference scheme, on which were built the waveform and phase trajectories hereditarity effect of stick-slip.

  2. Experimental and theoretical study of radon levels in a house

    International Nuclear Information System (INIS)

    Ameon, R.; Dupuis, M.; Marie, L.; Diez, O.; LionS, J.; Tymen, G.

    2006-01-01

    Full text of publication follows: Radon being a radioactive gas of natural origin is omnipresent everywhere at the surface of earth. It is created by the radium decay issued from the uranium contained in the earth crust and more specifically in granitic and volcanic subsoils. Because of the dilution due to air masses, its concentration in open air is low. On the other hand, radon may accumulate in the confined atmosphere of buildings and achieve high concentration levels. Across France, it has been estimated that 300 000 individual dwellings present concentration higher than the French reference level of 400 Bq.m -3 and that 60 000 other ones would exhibit concentration above 1 000 Bq.m -3 , the French warning threshold. Indoor radon concentration may vary significantly for various reasons, including design of buildings, radium content and texture of the soil in contact with the building's slab and walls, the under pressure value between the inside and outside and the fresh air supply rate. These considerations have led the I.R.S.N. to develop a code called R.A.D.O.N. 2 for conducting simple and methodical studies of indoor radon concentrations, to take into account the above-mentioned factors. But, the achievement of an effective diagnosis and risk management -aiding tool requires to first check its validity on the phenomenological model at the origin of the code. A 3-year experimental follow-up was, thus, conducted within an unoccupied house built on an uranium-bearing geological formation. After characterization of the subsoil, the instrumentation was implemented on site to continuously monitor the following parameters: - the radon source term in the building (exhalation rate of 222 Rn at the ground/building interface and at soil surface, radon concentration at the soil and in outdoor air), - the radon penetration by advection (differential pressure in the house basement), - the driving mechanisms for natural ventilation in the house (weather conditions, indoor

  3. Experimental and theoretical study of radon levels in a house

    Energy Technology Data Exchange (ETDEWEB)

    Ameon, R.; Dupuis, M.; Marie, L.; Diez, O.; LionS, J. [Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-roses (France); Tymen, G. [LARAAH, Universite de Bretagne Occidentale, Brest (France)

    2006-07-01

    Full text of publication follows: Radon being a radioactive gas of natural origin is omnipresent everywhere at the surface of earth. It is created by the radium decay issued from the uranium contained in the earth crust and more specifically in granitic and volcanic subsoils. Because of the dilution due to air masses, its concentration in open air is low. On the other hand, radon may accumulate in the confined atmosphere of buildings and achieve high concentration levels. Across France, it has been estimated that 300 000 individual dwellings present concentration higher than the French reference level of 400 Bq.m{sup -3} and that 60 000 other ones would exhibit concentration above 1 000 Bq.m{sup -3}, the French warning threshold. Indoor radon concentration may vary significantly for various reasons, including design of buildings, radium content and texture of the soil in contact with the building's slab and walls, the under pressure value between the inside and outside and the fresh air supply rate. These considerations have led the I.R.S.N. to develop a code called R.A.D.O.N. 2 for conducting simple and methodical studies of indoor radon concentrations, to take into account the above-mentioned factors. But, the achievement of an effective diagnosis and risk management -aiding tool requires to first check its validity on the phenomenological model at the origin of the code. A 3-year experimental follow-up was, thus, conducted within an unoccupied house built on an uranium-bearing geological formation. After characterization of the subsoil, the instrumentation was implemented on site to continuously monitor the following parameters: - the radon source term in the building (exhalation rate of {sup 222}Rn at the ground/building interface and at soil surface, radon concentration at the soil and in outdoor air), - the radon penetration by advection (differential pressure in the house basement), - the driving mechanisms for natural ventilation in the house (weather

  4. Radon -- an environmental hazard

    International Nuclear Information System (INIS)

    Faheem, M.; Rahman, R.; Rahman, S.; Matiullah

    2005-01-01

    Humans have always been exposed throughout its period of experience to naturally occurring sources of ionizing radiation or natural background radiation, It is an established fact that even these low background doses are harmful to man and cause increased cancer risk. About half of our radiation comes from radon, a radioactive gas coming from normal materials in the ground. Several building materials such as granite, bricks, sand, cement etc., contain uranium in various amounts. The radioactive gas /sup 222/Rn produced in these materials due to decay of 226Ra is transported to indoor air through diffusion and convective flow. It seeps out of soil and rocks, well water, building materials and other sources at a varied rate. Amongst the naturally occurring radioisotopes, radon is the most harmful one that can be a cause of lung cancer. Radon isotopes are born by the decay of radium and radium production in turns comes from uranium or thorium decay. For humans the greatest importance among Radon isotopes is attributed to /sup 222/Rn because it is the longest lived of the three naturally produced isotopes. Drinking water also poses a threat. Radon gas is dissolved in water and is released into the air via water faucets, showerheads, etc. the lack of understanding has so far lead to speculative estimates of pollutant related health hazards. (author)

  5. Modelling of radiation risk induced by radon and sources of Auger electrons

    International Nuclear Information System (INIS)

    Boem, R.

    2003-01-01

    This thesis follows the national and worldwide radon research and application Auger radionuclides in nuclear medicine. Results of this thesis can be summarised into several points: (1) For the prediction of cancer risk following the exposure, it is also necessary to consider the mean cycle time of target cells. From our analyses it can be concluded that the mean cycle time of target cells should exceed 100 days. (2) The value of excess relative risk is for smokers ERR/WLM = (2.4-4.1)x10 -3 WLM -1 and that of the nonsmokers ERR/WLM=(4.2-10.7)x10 -3 WLM -1 , considering the underground medium. Excess relative risk for the nonsmokers ERR/(Bq m -3 ) = (1.0-3.5) Bq -1 m 3 and for smokers ERR/(Bq m -3 ) = (0.3-1.2) 10 -3 Bq -1 m 3 is supposed in dwellings. (3) Microdosimetric models are very helpful and suitable for prediction of the radon risk for underground conditions, as well as for indoor radon risk evaluation and they are also able to take into account the influence of the smoking habit. (4) The spatial distribution of energy deposition events and their magnitude is an essential input to evaluate the effects of radiation on biological systems. Therefore, for the calculation of deposited energy from the DNA incorporated Auger emitters, it is necessary at the DNA level to employ the MC calculation. In an effort to save computer time and memory it is possible to use the fitted function for monoenergetic electrons for estimation of at least relative radiotoxicity. The value of energy deposited in a small volume (sphere of diameter 2 nm) can be considered as the first estimation of an Auger emitter's radiotoxicity. (author)

  6. Development of a predictive methodology for identifying high radon exhalation potential areas

    International Nuclear Information System (INIS)

    Ielsch, G.

    2001-01-01

    Radon 222 is a radioactive natural gas originating from the decay of radium 226 which itself originates from the decay of uranium 23 8 naturally present in rocks and soil. Inhalation of radon gas and its decay products is a potential health risk for man. Radon can accumulate in confined environments such as buildings, and is responsible for one third of the total radiological exposure of the general public to radiation. The problem of how to manage this risk then arises. The main difficulty encountered is due to the large variability of exposure to radon across the country. A prediction needs to be made of areas with the highest density of buildings with high radon levels. Exposure to radon varies depending on the degree of confinement of the habitat, the lifestyle of the occupants and particularly emission of radon from the surface of the soil on which the building is built. The purpose of this thesis is to elaborate a methodology for determining areas presenting a high potential for radon exhalation at the surface of the soil. The methodology adopted is based on quantification of radon exhalation at the surface, starting from a precise characterization of the main local geological and pedological parameters that control the radon source and its transport to the ground/atmosphere interface. The methodology proposed is innovative in that it combines a cartographic analysis, parameters integrated into a Geographic Information system, and a simplified model for vertical transport of radon by diffusion through pores in the soil. This methodology has been validated on two typical areas, in different geological contexts, and gives forecasts that generally agree with field observations. This makes it possible to identify areas with a high exhalation potential within a range of a few square kilometers. (author)

  7. Development of a quality assured calibration method for the PSI radon chamber reference atmosphere

    International Nuclear Information System (INIS)

    Schuler, C.; Butterweck-Dempewolf, G.; Vezzu, G.

    1997-01-01

    Radon detectors and measuring instruments are calibrated at the PSI Reference Laboratory for Radon Gas Concentration Measurements by exposing them to a calibrated radon reference atmosphere in the PSI radon chamber. A sophisticated and quality assured calibration technique was developed which guarantees the traceability of this radon chamber reference atmosphere to standards of internationally acknowledged primary laboratories. (author) 2 figs., 2 refs

  8. Radon-Instrumentation

    International Nuclear Information System (INIS)

    Moreno y Moreno, A.

    2003-01-01

    The presentation of the active and passive methods for radon, their identification and measure, instrumentation and characteristics are the objectives of this work. Active detectors: Active Alpha Cam Continuous Air Monitor, Model 758 of Victoreen, Model CMR-510 Continuous Radon Monitor of the Signature Femto-Tech. Passive detectors: SSNTD track detectors in solids Measurement Using Charcoal Canisters, disk of activated coal deposited in a metallic box Electrets Methodology. (Author)

  9. Soil gas radon and volcanic activity at El Hierro (Canary Islands) before and after the 2011-2012 submarine eruption

    Science.gov (United States)

    Barrancos, J.; Padilla, G.; Hernandez Perez, P. A.; Padron, E.; Perez, N.; Melian Rodriguez, G.; Nolasco, D.; Dionis, S.; Rodriguez, F.; Calvo, D.; Hernandez, I.

    2012-12-01

    El Hierro is the youngest and southernmost island of the Canarian archipelago and represents the summit of a volcanic shield elevating from the surrounding seafloor at depth of 4000 m to up to 1501 m above sea level. The island is believed to be near the present hotspot location in the Canaries with the oldest subaerial rocks dated at 1.12 Ma. The subaerial parts of the El Hierro rift zones (NE, NW and S Ridges) are characterized by tightly aligned dyke complexes with clusters of cinder cones as their surface expressions. Since July 16, 2011, an anomalous seismicity at El Hierro Island was recorded by IGN seismic network. Volcanic tremor started at 05:15 hours on October 10, followed on the afternoon of October 12 by a green discolouration of seawater, strong bubbling and degassing indicating the initial stage of submarine volcanic eruption at approximately 2 km off the coast of La Restinga, El Hierro. Soil gas 222Rn and 220Rn activities were continuously measured during the period of the recent volcanic unrest occurred at El Hierro, at two different geochemical stations, HIE02 and HIE03. Significant increases in soil 222Rn activity and 222Rn/220Rn ratio from the soil were observed at both stations prior the submarine eruption off the coast of El Hierro, showing the highest increases before the eruption onset and the occurrence of the strongest seismic event (M=4.6). A statistical analysis showed that the long-term trend of the filtered data corresponded closely to the seismic energy released during the volcanic unrest. The observed increases of 222Rn are related to the rock fracturing processes (seismic activity) and the magmatic CO2 outflow increase, as observed in HIE03 station. Under these results, we find that continuous soil radon studies are important for evaluating the volcanic activity of El Hierro and they demonstrate the potential of applying continuous monitoring of soil radon to improve and optimize the detection of early warning signals of future

  10. Radon thematic days - Conference proceedings

    International Nuclear Information System (INIS)

    2011-03-01

    This document brings together the available presentations given at the Radon thematic days organized by the French society of radiation protection (SFRP). Twenty five presentations (slides) are compiled in the document and deal with: 1 - General introduction about radon (Sebastien Baechler, IRA); 2 - Survey of epidemiological studies (Dominique Laurier, IRSN); 3 - Dosimetric model (Eric Blanchardon, Estelle Davesne, IRSN); 4 - Radon issue in Franche-Comte: measurement of the domestic exposure and evaluation of the associated health impact (Francois Clinard, InVS); 5 - WHO's (World Health Organization) viewpoint in limiting radon exposure in homes (Ferid Shannoun, OMS); 6 - Radon measurement techniques (Roselyne Ameon, IRSN); 7 - Quality of radon measurements (Francois Bochud, IRA); 8 - International recommendations (Jean-Francois Lecomte, IRSN); 9 - Radon management strategy in Switzerland - 1994-2014 (Christophe Murith, OFSP); 10 - 2011-2015 action plan for radon risk management (Jean-Luc Godet, Eric Dechaux, ASN); 11 - Radon at work place in Switzerland (Lisa Pedrazzi, SUVA); 12 - Strategies of radiation protection optimization in radon exposure situations (Cynthia Reaud, CEPN); 13 - Mapping of the radon potential of geologic formations in France (Geraldine Ielsch, IRSN); 14 - Radon database in Switzerland (Martha Gruson, OFSP); 15 - Radon 222 in taps water (Jeanne Loyen, IRSN); 16 - Buildings protection methods (Bernard Collignan, CSTB, Roselyne Ameon, IRSN); 17 - Preventive and sanitation measures in Switzerland (Claudio Valsangiacomo, SUPSI); 18 - Training and support approach for building specialists (Joelle Goyette-Pernot, Fribourg engineers and architects' school); 19 - Status of radon bulk activity measurements performed between 2005-2010 in public areas (Cyril Pineau, ASN); 20 - Neuchatel Canton experiments (Didier Racine, SENE); 21 - Montbeliard region experience in the radon risk management (Isabelle Netillard, Pays de Montbeliard Agglomeration); 22

  11. Radon and radon daughters in South African underground mines

    International Nuclear Information System (INIS)

    Rolle, R.

    1980-01-01

    Radon and the radon daughters are the radionuclides which primarily determine the level of the radiation hazard in underground uranium mines and to a smaller extent in non-uranium mines. Radon is a gas, and its daughters adsorb on aerosol particles which are of respirable size. The hazard thus arises from the alpha decay of radon and its daughters in contact with lung tissue. Radon is itself part of the uranium decay chain. The major radionuclide, 238 U, decays successively through thirteen shorter-lived radionuclides to 206 Pb. Radon is the only gaseous decay product at room temperature; the other twelve are solids. The main hazard presented by the uranium decay chain is normally determined by the radon concentration because gaseous transport can bring alpha emitters close to sensitive tissue. There is no such transport route for the other alpha emitters, and the level of beta and gamma radiation caused by the uranium decay chain generally presents a far lower external radiation hazard. Radon itself is the heaviest of the noble gases, which are He, Ne, Ar, Kr, Xe and Rn. Its chemical reactions are of no concern in regard to its potential hazard in mines as it may be considered inert. It does, however, have a solubility ten times higher than oxygen in water, and this can play a significant part in assisting the movement of the gas from the rock into airways. Radon continuously emanates into mine workings from uranium ores and from the uranium present at low concentrations in practically any rock. It has been found that the control of the exposure level is most effectively achieved by sound ventilation practices. In South African mines the standard of ventilation is generally high and exposure to radon and radon daughters is at acceptably low levels

  12. Radon gas-exchange rate through the interface sea atmosphere in the coast

    International Nuclear Information System (INIS)

    Duenas, C.; Fernandez, M.C.; Perez Martinez, M.

    1985-01-01

    The Rn gas exchange velocity through the interface sea atmosphere has been estimated. Our measurements have been made in a sampler station located in Malaga bay, obtaining a mean value of 0.45 m/d. The corresponding magnitude of the thickness of boundary layer is 316μ. Experimental results are discussed. No clear relationship can be found between the gas exchange rate and wind speed. (author)

  13. Mapping indoor radon-222 in Denmark: Design and test of the statistical model used in the second nationwide survey

    DEFF Research Database (Denmark)

    Andersen, C.E.; Ulbak, K.; Damkjær, A.

    2001-01-01

    In Denmark, a new survey of indoor radon-222 has been carried out. 1-year alpha track measurements (CR-39) have been made in 3019 single-family houses. There are from 3 to 23 house measurements in each of the 275 municipalities. Within each municipality, houses have been selected randomly. One...... important outcome of the survey is the prediction of the fraction of houses in each municipality with an annual average radon concentration above 200 Bq m(-3). To obtain the most accurate estimate and to assess the associated uncertainties, a statistical model has been developed. The purpose of this paper...

  14. THERMODYNAMIC MODEL OF GAS HYDRATES

    OpenAIRE

    Недоступ, В. И.; Недоступ, О. В.

    2015-01-01

    The interest to gas hydrates grows last years. Therefore working out of reliable settlement-theoretical methods of definition of their properties is necessary. The thermodynamic model of gas hydrates in which the central place occupies a behaviour of guest molecule in cell is described. The equations of interaction of molecule hydrate formative gas with cell are received, and also an enthalpy and energy of output of molecule from a cell are determined. The equation for calculation of thermody...

  15. Radon assessment in thermal waters in Imbabura and Pichincha provinces

    International Nuclear Information System (INIS)

    Aragon, Mayra

    2001-01-01

    The radon is a radioactive, odorless and colorless gas, that generated in the terrestrial crust by the radioactive decay of the radio, originating of the chain of disintegration of the Uranium-238, can migrate considerable distances during its short time of life (3.82 days), from the ground to the water and later to the atmosphere. For the accomplishment of the preliminary study of quantification of radon in thermal sources, it was come to the sampling from radon-222 in bath waters different from the provinces of Pichincha and Imbabura. For which a particle accountant was used alpha, that uses the method of flashing, emitted by ionizing particles at the moment at which the radium decays in its descendant radon, and this one in its next descendants. The water samples are analyzed in the Pylon model RM-1003, particle accountant alpha, that uses for the harvesting of the gas, cameras that contain sensible detectors activated zinc sulfide cells with silver. For this sampling it was taken into account qualitative factors like: rain temperature, presence, origin of the source, proximity of some hill or volcano, presence of seismic movements, among others. These parameters could affect to the measurements of concentration of radon. Of the obtained results, we can conclude that of the 13 bath, those of the province of Pichincha, specially three of them (Tesalia, Sillunchi, Cunuyacu), contain greater concentration of radon that those of the province of Imbabura. In addition in general for all the selected bath it was verified that the concentration of radon is greater for the source than for the swimming pool. Finally it is possible to be emphasized values of concentration of radon that are around 1000-15000 Bq/m3 for the source, and the swimming pool of 100-800 Bq/m3. (The author)

  16. Modelling isothermal fission gas release

    International Nuclear Information System (INIS)

    Uffelen, P. van

    2002-01-01

    The present paper presents a new fission gas release model consisting of two coupled modules. The first module treats the behaviour of the fission gas atoms in spherical grains with a distribution of grain sizes. This module considers single atom diffusion, trapping and fission induced re-solution of gas atoms associated with intragranular bubbles, and re-solution from the grain boundary into a few layers adjacent to the grain face. The second module considers the transport of the fission gas atoms along the grain boundaries. Four mechanisms are incorporated: diffusion controlled precipitation of gas atoms into bubbles, grain boundary bubble sweeping, re-solution of gas atoms into the adjacent grains and gas flow through open porosity when grain boundary bubbles are interconnected. The interconnection of the intergranular bubbles is affected both by the fraction of the grain face occupied by the cavities and by the balance between the bubble internal pressure and the hydrostatic pressure surrounding the bubbles. The model is under validation. In a first step, some numerical routines have been tested by means of analytic solutions. In a second step, the fission gas release model has been coupled with the FTEMP2 code of the Halden Reactor Project for the temperature distribution in the pellets. A parametric study of some steady-state irradiations and one power ramp have been simulated successfully. In particular, the Halden threshold for fission gas release and two simplified FUMEX cases have been computed and are summarised. (author)

  17. The 1996 Radon Intercomparison Exercise at PSI

    International Nuclear Information System (INIS)

    Schuler, C.; Butterweck-Dempewolf, G.

    1997-05-01

    The 1996 Radon Intercomparison Exercise at PSI was organized by the PSI Reference Laboratory for Radon Gas Activity Concentration Measurements. A total of 14 laboratories, companies and institutions participated with radon gas detectors and measuring instruments. The detectors and instruments were exposed in the PSI radon chamber during seven days in a reference atmosphere with an average radon gas concentration of about 6000 Bqm -3 . Comparison of the results of electret ionization chambers, track etch detectors and measuring instruments with the PSI target value showed the criteria for traceability and reproducibility demanded by the Federal Office for Health for the acknowledgement of Swiss Radon Gas Measurement Laboratories to be fulfilled for all participants. Exposure of track etch detectors stored for more than one year demonstrated that this detector type can suffer sensitivity loss by a too long storage period. (author) figs., tabs., refs

  18. The control of radon levels in houses

    International Nuclear Information System (INIS)

    Al-Jarallah, M. B. I.

    2007-01-01

    The article speaks about radon entry ways to houses, the technologies of controlling the level of radon in indoors and four possible ways to solve the problem of high concentration of radon gas in housing and protection from being gathered to a certain extent that is harmful to health. These methods are: removal of the radon source, modifying the radon source, ventilation and air filtration. The article also addresses the impact of reducing the consumption of heating energy in homes and buildings using thermal insulators in floors, walls, ceilings and doors and making double glazed windows that confine the air. It has been proven that there is a steady relationship between energy conservation measures in housing and the increase of radon concentration by two to three times. In a lot of buildings, where conservation measures have been taken, materials to conserve heat are used, which themselves launch radon and this may lead to increased levels of the gas in the housing.

  19. Monitoring of soil radon by SSNTD in Eastern India in search of possible earthquake precursor.

    Science.gov (United States)

    Deb, Argha; Gazi, Mahasin; Ghosh, Jayita; Chowdhury, Saheli; Barman, Chiranjib

    2018-04-01

    The present paper deals with monitoring soil radon-222 concentration at two different locations, designated Site A and Site B, 200 m apart at Jadavpur University campus, Kolkata, India, with a view to find possible precursors for the earthquakes that occurred within a few hundred kilometers from the monitoring site. The solid state nuclear track detector CR-39 has been used for detection of radon gas coming out from soil. Radon-222 time series at both locations during the period August 2012-December 2013 have been analysed. Distinct anomalies in the soil radon time series have been observed for seven earthquakes of magnitude greater than 4.0 M that occurred during this time. Of these, radon anomalies for two earthquakes have been observed at both locations A and B. Absence of anomalies for some other earthquakes has been discussed, and the observations have been compared with some earthquake precursor models. Copyright © 2018. Published by Elsevier Ltd.

  20. Effect of ventilation on concentrations of indoor radon- and thoron-progeny: Experimental verification of a simple model

    International Nuclear Information System (INIS)

    Sheets, R.W.; Thompson, C.C.

    1993-01-01

    Different models relating the dependence of radon ( 222 Rn)- and thoron ( 220 Rn)-progeny activities on room ventilation rates are presented in the literature. Some of these models predict that, as the rate of ventilation increases, activities of thoron progeny decrease more rapidly than those of radon progeny. Other models predict the opposite trend. In this study alpha activities of the radon progeny, 218 Po, 214 Pb, and 214 Bi, together with the thoron progeny 212 Pb, were measured over periods of several days in two rooms of a closed, heated house. Effective ventilation rates were calculated from measured 214 Pb/ 214 Bi ratios. A simple model in which progeny concentrations decrease by radioactive decay and by dilution with outside air has been used to calculate 212 Pb/ 214 Pb ratios as a function of ventilation rate. Calculated ratios are found to correlate significantly with experimentally-determined ratios (R 2 ∼ 0.5--0.8 at p < 0.005) confirming that, for this house, thoron progeny activities decrease faster than radon progeny activities with increasing rates of ventilation

  1. Radon migration from soil to a house. Computer modelling and its verification on the base of measurements in living houses

    International Nuclear Information System (INIS)

    Janik, M.

    2005-09-01

    In this thesis the Loureiro model of radon migration from soil to a house has been verified. For this purpose the computer code TRIAD has been used. The input data for this code are the ground penetrability and porosity. Methods for determination of these parameters have bee developed and equipment for its measurements has been manufactured and tested

  2. Radiation levels of radon gas and its progeny in labor activities of mine interior and their effects in the Bolivian workers to 4000 m

    International Nuclear Information System (INIS)

    Mamani M, R.; Claros J, J. T.; Vasquez A, R.; Chirveches, H.; Weyer, J.; Arnold, D.

    2014-08-01

    The objectives of this study are guided to determine the radiation charges to those that the mining workers are exposed, in order to assume the appropriate protection measures. The first phase of this study begun in March of 2009, with the support of the Freiberg University (Germany), has been preceded of different scientific events and preparatory measurements in the Universidad Autonoma Tomas Frias (UATF) and Cerro Rico de Potosi. Experimentally the presence of radon gas has been quantified by means of measurements in 7 mines of Cerro Rico de Potosi, the COMSUR mines (today SINCHY WAYRA) and the state mining company COMIBOL (Oruro-Huanuni), using the measurement equipment Alpha Zaeller-2 (AZ-2). The Radon-222 that emerges of the interior of the fractured rocks and/or loose rocks, with more intensity if they are fresh, is inhaled by the mining worker. Considering the breathing parameters (1, 2 m 3 /h), recommended by the ICRP, was observed that the miners breathing of the region is more bigger, due to the high effort that they develop in the work. Therefore, the calculation results of the concentration of the radiation activity of Radon, allow assuming that this is the causing of the damage to the lungs in the human body. Outdoor or in superficial tunnels, the impact is low or imperceptible. But when the process is verified to more depths in an underground mine, or not properly ventilated, the concentration as well as the exposure dose to the radiation of radon gas is increased to amazing values. Assuming that the maximum permissible limit is of 20 mSv, the study has established some values that exceeded this limit in the Bolivian mining, not controlled in this field until now. The component of the medical study, through exams: hematology and spirometric, notes that, by the complex inhalation of: air + powders + Radon gas and others in his working environment, contribute strongly to the generation of lethal illnesses in the mining worker, as the Poliglobulia

  3. The correlations between Radon in soil gas and its exhalation and concentration in air in the southern part of Syria

    International Nuclear Information System (INIS)

    Shweikani, R.; Hushari, M.

    2005-01-01

    The aim of this work is to measure the concentration of the radon ( 222 Rn) in soil air, 222 Rn exhalation from soil and 222 Rn in outdoor air which may have great influence on 222 Rn levels in houses. 222 Ra activity concentrations were also determined in soil samples. The studied areas are located in southern part of Syria. The common bed rock of this area is black and massive granite which are poor in uranium content [Jubeli Y.M., 1990. Uranium exploration in Syria. Internal Technical Report, vol. 1 (in English), vol. 2 (in Arabic), SAEC, Damascus; Technoexport (USSR), 1966. In: Ponikarov (Ed.), The Geological Map of Syria Scale: 1:200.000, Ministry of Industry, Damascus, Syria]. Results showed that the maximum measurement in all areas was 32500Bqm -3 in soil air with an exhalation rate of 9Bqm -2 s -1 in Darra region and 66.43Bqm -3 of radon in open air, with 77Bqkg -1 of radium content in soil (Damascus suburb). In addition, correlations between Rn in soil and exhalation of Radon from soil and radon in houses were found in some areas (Sweda and Darra), while, no correlations were found in other studied areas. Moreover, no correlation between radon in houses and radon measurements in soil and in outdoors were found. This was attributed to the methodology used and the influence of building design and inhabitants behavior

  4. Measurements of radon exhalation from building materials under model climate conditions

    International Nuclear Information System (INIS)

    Jann, O.; Schneider, U.; Koeppke, J.; Lehmann, R.

    2003-01-01

    The inhalation of 222 Rn (radon) is the most important reason for lung cancer as a result of smoking. The cause for enhanced radon concentration in the air of buildings is mostly the building ground. But also building products can lead to increased radon concentrations in indoor air when the products contain raw materials or residues with higher contents of 226 Ra (radium), especially in combination with low air exchange rates. For a realistic estimation of radon concentrations it is helpful to perform emission tests on the basis of emission test chambers. Emissions test chambers are already used successfully for the measurement of volatile organic compounds (VOC) emitted from different materials and products. The analysis of radon in air was performed with a test device based on the principle of ionisation chamber (ATMOS 12 D). It could be show that radon concentrations emitted from building materials can be determined reliably if certain boundary conditions such as temperature, relative humidity and especially area specific air flow rate are met. It was also shown that reduced area specific air flow rates or reduced air exchange rates lead to higher radon concentrations. It is remarkable that no conclusion can be drawn from the activity concentration of radium to the radon concentration in the air. Therefore in some cases much higher radon concentrations in air were determined that had been expected. Obviously diffusion within the material plays an important role. (orig.)

  5. Characterisation of non-aerosol-bound fractions of radon decay products under environmental conditions

    International Nuclear Information System (INIS)

    Pagelkopf, P.; Porstendoerfer, J.

    2004-01-01

    Dose-relevant factors such as the concentration and size distribution of radon decay products are strongly influenced by the charge-carrying fraction and state of charge of the first radon decay product, 2 18Po. The charge of 2 18Po influences its own mobility and hence its attachment to aerosols and deposition on surfaces, also referred to as ''plating out''. The mobility of 2 18Po can be described in terms of its diffusion coefficient. The goal of the present study was to determine theoretically as well as practically the charge-carrying fraction of radon decay products 2 18Po and 2 14Pb under room air conditions and to design and construct an electrical mobility spectrometer. The spatial model developed by Jacobi and modified by Porstendoerfer for calculating the concentration of unattached radon decay products in indoor and outdoor air under steady-state conditions was extended to permit a differentiated description of the charge-carrying and neutral unattached fractions of radon decay products 2 18Po and 2 14Pb. An 8 m 2 chamber permitting chamber air control in terms of radon gas concentration and humidity was built in order to study the behaviour of radon decay products. The charge-carrying fraction of unattached radon decay products 218 Po and 214 Pb was measured in this chamber. A technique referred to as the online backscreen technique (OBST) was developed to permit the continuous measurement of unattached decay products. The technique involves the diffusive deposition of unattached radon decay products from a laminar flow onto a wire lattice and their subsequent measurement. The total fraction of decay products is then determined by means of the filtration method. Furthermore, all parameters required for modelling such as radon gas, decay product and aerosol concentrations as well as air humidity, temperature and ion dose rate were measured [de

  6. Gas Turbine Engine Behavioral Modeling

    OpenAIRE

    Meyer, Richard T; DeCarlo, Raymond A.; Pekarek, Steve; Doktorcik, Chris

    2014-01-01

    This paper develops and validates a power flow behavioral model of a gas tur- bine engine with a gas generator and free power turbine. “Simple” mathematical expressions to describe the engine’s power flow are derived from an understand- ing of basic thermodynamic and mechanical interactions taking place within the engine. The engine behavioral model presented is suitable for developing a supervisory level controller of an electrical power system that contains the en- gine connected to a gener...

  7. A model of the precaution adoption process: evidence from home radon testing

    International Nuclear Information System (INIS)

    Weinstein, N.D.; Sandman, P.M.

    1992-01-01

    The authors present the precaution adoption process model--a stage theory consisting of seven distinct states between ignorance and completed preventive action. The stages are 'unaware of the issue,' 'aware of the issue but not personally engaged,' 'engaged and deciding what to do,' 'planning to act but not yet having acted,' 'having decided not to act,' 'acting,' and 'maintenance.' The theory asserts that these stages represent qualitatively different patterns of behavior, beliefs, and experience and that the factors that produce transitions between stages vary depending on the specific transition being considered. Data from seven studies of home radon testing are examined to test some of the claims made by this model. Stage theories of protective behavior are contrasted with theories that see precaution adoption in terms of movement along a single continuum of action likelihood.32 references

  8. Prediction of residential radon exposure of the whole Swiss population: comparison of model-based predictions with measurement-based predictions.

    Science.gov (United States)

    Hauri, D D; Huss, A; Zimmermann, F; Kuehni, C E; Röösli, M

    2013-10-01

    Radon plays an important role for human exposure to natural sources of ionizing radiation. The aim of this article is to compare two approaches to estimate mean radon exposure in the Swiss population: model-based predictions at individual level and measurement-based predictions based on measurements aggregated at municipality level. A nationwide model was used to predict radon levels in each household and for each individual based on the corresponding tectonic unit, building age, building type, soil texture, degree of urbanization, and floor. Measurement-based predictions were carried out within a health impact assessment on residential radon and lung cancer. Mean measured radon levels were corrected for the average floor distribution and weighted with population size of each municipality. Model-based predictions yielded a mean radon exposure of the Swiss population of 84.1 Bq/m(3) . Measurement-based predictions yielded an average exposure of 78 Bq/m(3) . This study demonstrates that the model- and the measurement-based predictions provided similar results. The advantage of the measurement-based approach is its simplicity, which is sufficient for assessing exposure distribution in a population. The model-based approach allows predicting radon levels at specific sites, which is needed in an epidemiological study, and the results do not depend on how the measurement sites have been selected. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Application of underwater radon measurements in geology

    Energy Technology Data Exchange (ETDEWEB)

    Varhegyi, A.; Baranyi, I.; Gerzson, I. (Mecsek Ore Mining Enterprise, Pecs (Hungary)); Somogyi, G.; Hakl, J.; Hunyadi, I. (Magyar Tudomanyos Akademia, Debrecen (Hungary). Atommag Kutato Intezete)

    1988-01-01

    Based on the observed phenomenon of geogas migration in microbubble form from deeper regions, the authors have developed a new model for the vertical transport of radon released from deeper sources. The physical properties of the rock relating to the upflow of microbubbles below the groundwater level are considered and the radon transport parameter of rocks is introduced. The vertical distribution of radon concentration in the case of a multi-layered geological model is given and the penetration depth of underwater radon measurements is examined. Aspects of underwater radon detection by the nuclear track detector technique are analyzed. The radon transport model gives a new theoretical basis for several applications of radon measurements in geology. The advantages of underwater radon detection have already been proved in uranium exploration. Further geological applications are proposed in earthquake prediction, in volcanology, in the survey of active faults and thermal waters. (author).

  10. Study of underground radon transport

    International Nuclear Information System (INIS)

    Csige, I.; Hakl, J.; Lenart, L.

    1990-01-01

    The soil gas radon content measurements with solid state nuclear track detectors (SSNTDs) are widely used in geoscience, for instance in uranium exploration and earthquake prediction. In these applications the radon frequently is used as a natural tracer of underground fluid transport processes. Obviously, to get the soil radon measuring method more and more effective the study of these transport processes in deeper part of the Earth is fundamental. The Track Detector Group in the Institute of Nuclear Research of the Hungarian Academy of Sciences in Debrecen has been performing environmental radon activity concentration measurements since 1977 with alpha sensitive SSNTDs. These types of measurements were initiated and widely used by the late head of the group Dr. G. Somogyi, who devoted his life to better understanding of the nature. The measurements in caves, springs and drilled wells proved to be effective to study these underground radon transport processes. We are glad to present some results of our investigations. 7 refs, 7 figs

  11. Application of nuclear track detectors for radon related measurments

    International Nuclear Information System (INIS)

    Abu-Jarad, F.A.

    1988-01-01

    The application of nuclear track detectors for radon related measurements is discussed. The ''Can Technique'', used for measuring radon emanation from building materials, walls and soil; the ''Working Level Monitor'', used for measuring short period working levels of radon daughters in houses; and ''Passive Radon Dosimeters'', used to measure radon levels in houses for long term (few months) periods are described. Application of nuclear track detectors for measuring the radon daughters plate-out on the surface of mixing fan blades and walls are discussed. The uranium content of some wall papers was found to be 6 ppm. The variation of radon progeny concentration in the same room was measured and supported by another study through Gas Chromatograph measurements. The independence of radon concentration on room level in high-rise buildings was established. The effect of sub-floor radon emanation on radon concentration in houses is dependent on whether there is sub-floor ventilation or not. (author)

  12. Radon in homes: The Alaskan experience

    International Nuclear Information System (INIS)

    Seifert, R.D.

    1990-01-01

    For the past four years, since radon was first found to be a concern in Alaska in 1986, the interest and awareness of radon as a special housing and health concern has continued to grow. This paper will discuss the features of a house in Alaska which would characterize it as at risk for radon, and also those efforts at mitigation which have been most effective in reducing radon under Alaskan conditions. Clearly radon must be able to enter a home in order to be a problem. Riefenstuhl and Kline (personal communication, 1988) have analyzed the conditions for radon transport from soils to home interiors very lucidly through the following scheme: four factors must exist in a house locale for it to be a radon at risk house. Two of the factors are geological in nature: (1) there must be adequate uranium and therefore ample radon to provide a source for transport; (2) there must be enough permeability in the soil to allow rapid soil gas movement to carry radon from its origin to the interior of the home within two half-lives of time (six days) or so. The other two factors are determined by the structure of the house itself and the way in which it is operated: (3) the house must have soil contact and imperfections, holes, cracks, intentional perforations which allow movement of soil gas with radon through the envelope of the basement or crawlspace; (4) there must be a lower pressure inside the house than in the soil so that soil gas flows into the house. All four of these characteristics are required to have radon be a problem. The absence of any single characteristic will eliminate radon (in general). This presents a series of options for mitigation of radon then, since elimination of any of the four characteristics will mitigate radon

  13. Field investigation of surface-deposited radon progeny as a possible predictor of the airborne radon progeny dose rate.

    Science.gov (United States)

    Sun, Kainan; Steck, Daniel J; Field, R William

    2009-08-01

    The quantitative relationships between radon gas concentration, the surface-deposited activities of various radon progeny, the airborne radon progeny dose rate, and various residential environmental factors were investigated through actual field measurements in 38 selected Iowa houses occupied by either smokers or nonsmokers. Airborne dose rate was calculated from unattached and attached potential alpha energy concentrations (PAECs) using two dosimetric models with different activity-size weighting factors. These models are labeled Pdose and Jdose, respectively. Surface-deposited 218Po and 214Po were found significantly correlated to radon, unattached PAEC, and both airborne dose rates (p fireplace, or usage of a ceiling fan significantly, or marginally significantly, reduced the Pdose to 0.65 (90% CI 0.42-0.996), 0.54 (90% CI 0.28-1.02), and 0.66 (90% CI 0.45-0.96), respectively. For Jdose, only the usage of a ceiling fan significantly reduced the dose rate to 0.57 (90% CI 0.39-0.85). In smoking environments, deposited 218Po was a significant negative predictor for Pdose (RR 0.68, 90% CI 0.55-0.84) after adjusting for long-term 222Rn and environmental factors. A significant decrease of 0.72 (90% CI 0.64-0.83) in the mean Pdose was noted, after adjusting for the radon and radon progeny effects and other environmental factors, for every 10 additional cigarettes smoked in the room. A significant increase of 1.71 in the mean Pdose was found for large room size relative to small room size (90% CI 1.08-2.79) after adjusting for the radon and radon progeny effects as well as other environmental factors. Fireplace usage was found to significantly increase the mean Pdose to 1.71 (90% CI 1.20-2.45) after adjusting for other factors.

  14. Measurement of radon-222 concentration in environment sampled within short time using charcoal detector

    International Nuclear Information System (INIS)

    Yamasaki, Tadashi; Sekiyama, Shigenobu; Tokin, Mina; Nakayasu, Yumiko; Watanabe, Tamaki.

    1994-01-01

    The concentration of 222 Rn in air sampled within a very short period of time was measured using activated charcoal as the adsorber. The detector is the plastic canister containing mixture of the activated charcoal and the silica gel. The radon gas was adsorbed in the charcoal in the radon chamber at the temperature of 25degC. A little amount of liquid scintillation cocktail was added into the vial of liquid scintillation counter with the canister. The radon in the charcoal was extracted in the liquid scintillation cocktail. Alpha particles emitted from radon and its daughter nuclei in the cocktail were detected using the liquid scintillation counter. Present method has advantages of not only short sampling time of air but also adsorption of radon in charcoal under a constant temperature. The concentration of radon in air down to 2 Bq/m 3 could be detected. A kinetic model for adsorption of radon in the charcoal is also presented. The ratio of radon concentration in the charcoal to that in air under the equilibrium state of adsorption was estimated to be from 6.1 to 6.8 m 3 /kg at the temperature of 25degC. (author)

  15. The Noble Gas Radon ({sup 222}Rn) as a Hydrogeologic Tracer of Groundwater Inputs to Rivers and Hyporheic Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Stellato, L. [Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE), Seconda Universita degli Studi di Napoli, Caserta (Italy); Newman, B. D. [Isotope Hydrology Section, International Atomic Energy Agency, Vienna (Austria)

    2013-05-15

    The study of nutrient dynamics in lotic ecosystems often requires background knowledge of the hydrologic processes occurring both at large scales and at small scales in order to adopt effective management practices. In particular, surface water/subsurface water interactions can significantly alter nutrient loading in streams and rivers. Two case studies are reported as examples of large scale and small scale investigations carried out by means of an integrated approach where {sup 222}Rn was used: (i) to determine fractions of groundwater inflow to total discharge of a river and to identify sections with flow-through conditions, applying a degassing corrected, two component mixing model; (ii) to estimate water residence time within the hyporheic zone by applying a solute mass balance equation based on radon disequilibrium between pore water and stream water. The two case studies demonstrate that {sup 222}Rn is an effective tool in the study of interactions between surface and subsurface waters when groundwater inputs to rivers have to be quantified and in estimating the residence time of surface water in the hyporheic zone. However, an integrated approach including other hydrological and biogeochemical measurements is always recommended when complex processes have to be elucidated. (author)

  16. Modelling gas markets - a survey

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    This report reviews research of relevance to the analysis of present and future developments of the European natural gas market. The research activities considered are confined to (1) numerical models for gas markets, (2) analyses of energy demand, and (3) analyses of behaviour and cost structures in the transmission and distribution sector. Most of the market models are strictly micro economic and assume perfect competition or a game-theoretical equilibrium. They use sophisticated solution concepts, but very simplified specifications of supply and demand functions. Most of the research on demand is econometric analyses. These have more detailed model specification than have the aggregated market models. It is found, however, that the econometric literature based on neo-classical economics has not yielded unambiguous results and the specifications disregard important real world aspects of gas demand. The section on demand concludes that the extent of the gas grid is an important determinant for gas demand, but there has been virtually no research on what determines this variable. Data about transmission and distribution of gas in Europe is scarce and only a few non-econometric and virtually no econometric analyses are available. However, some conclusions can be made from relevant North American literature: (1) there has been significant autonomous technical progress in the transmission industry, (2) distribution costs strongly depend on geographical and other conditions, and (3) ownership, whether private or public, may be important for distribution costs and pricing policies. 56 refs., 3 figs., 1 tab.

  17. Modelling gas markets - a survey

    International Nuclear Information System (INIS)

    1997-01-01

    This report reviews research of relevance to the analysis of present and future developments of the European natural gas market. The research activities considered are confined to (1) numerical models for gas markets, (2) analyses of energy demand, and (3) analyses of behaviour and cost structures in the transmission and distribution sector. Most of the market models are strictly micro economic and assume perfect competition or a game-theoretical equilibrium. They use sophisticated solution concepts, but very simplified specifications of supply and demand functions. Most of the research on demand is econometric analyses. These have more detailed model specification than have the aggregated market models. It is found, however, that the econometric literature based on neo-classical economics has not yielded unambiguous results and the specifications disregard important real world aspects of gas demand. The section on demand concludes that the extent of the gas grid is an important determinant for gas demand, but there has been virtually no research on what determines this variable. Data about transmission and distribution of gas in Europe is scarce and only a few non-econometric and virtually no econometric analyses are available. However, some conclusions can be made from relevant North American literature: (1) there has been significant autonomous technical progress in the transmission industry, (2) distribution costs strongly depend on geographical and other conditions, and (3) ownership, whether private or public, may be important for distribution costs and pricing policies. 56 refs., 3 figs., 1 tab

  18. Study of radon dispersion in typical dwelling using CFD modeling combined with passive-active measurements

    Science.gov (United States)

    Rabi, R.; Oufni, L.

    2017-10-01

    Inhalation of radon (222Rn) and its decay products are a major source of natural radiation exposure. It is known from recent surveys in many countries that radon and its progeny contribute significantly to total inhalation dose and it is fairly established that radon when inhaled in large quantity causes lung disorder. Indoor air conditions and ventilation systems strongly influence the indoor radon concentration. This study focuses on investigating both numerically and experimentally the influence of environmental conditions on the indoor radon concentration and spatial distribution. The numerical results showed that ventilation rate, temperature and humidity have significant impacts on both radon content and distribution. The variations of radon concentration with the ventilation, temperature and relative humidity are discussed. The measurement results show the diurnal variations of the indoor radon concentration are found to exhibit a positive correlation with relative humidity and negatively correlate with the air temperature. The analytic solution is used to validate the numeric results. The comparison amongst analytical, numerical and measurement results shows close agreement.

  19. The use of radon as an earthquake precursor

    International Nuclear Information System (INIS)

    Ramola, R.C.; Singh, M.; Sandhu, A.S.; Singh, S.; Virk, H.S.

    1990-01-01

    Radon monitoring for earthquake prediction is part of an integral approach since the discovery of coherent and time anomalous radon concentrations prior to, during and after the 1966 Tashkent earthquake. In this paper some studies of groundwater and soil gas radon content in relation to earthquake activities are reviewed. Laboratory experiments and the development of groundwater and soil gas radon monitoring systems are described. In addition, radon monitoring studies conducted at the Guru Nanak Dev University Campus since 1986 are presented in detail. During these studies some anomalous changes in radon concentration were recorded before earthquakes occurred in the region. The anomalous radon increases are independent of meteorological conditions and appear to be caused by strain changes, which precede the earthquake. Anomalous changes in radon concentration before an earthquake suggest that radon monitoring can serve as an additional technique in the earthquake prediction programme in India. (author)

  20. Experience from using plastic film in radon measurement

    International Nuclear Information System (INIS)

    Joensson, G.

    1999-01-01

    Plastic film is a useful detector of radon gas. The method of detection of the gas is used for several decades to measure radon concentrations both indoors and in soil. Experiences from radon measurements in Sweden indoors, in soil and in water using the plastic film Kodak LR 115-II are discussed in this report. Some examples are given from various projects. One example is taken from a large scale mapping of indoor radon levels in houses, where the building material is the main source of radon. In another example the measurements from a large scale soil radon mapping are discussed. The use of the plastic film for measurements of radon levels in water is also discussed. All the investigations are made in order to give the authorities concerned information of the radon situation and to study the connection between high indoor radon levels and various types of cancers

  1. Assessment of inhalation and ingestion doses from exposure to radon gas using passive and active detecting techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, A. H.; Jafaar, M. S. [Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

    2011-07-01

    The aim of this study was to assess an environmental hazard of radon exhalation rate from the samples of soil and drinking water in selected locations in Iraqi Kurdistan, passive (CR-39NTDs) and active (RAD7) detecting techniques has been employed. Long and short term measurements of emitted radon concentrations were estimated for 124 houses. High and lower radon concentration in soil samples was in the cities of Hajyawa and Er. Tyrawa, respectively. Moreover, for drinking water, high and low radon concentration was in the cities of Similan and Kelak, respectively. A comparison between our results with that mentioned in international reports had been done. Average annual dose equivalent to the bronchial epithelium, stomach and whole body in the cities of Kelak and Similan are estimated, and it was varied from 0.04{+-}0.01 mSv to 0.547{+-}0.018 mSv, (2.832{+-}0.22)x10{sup -5} to (11.972{+-}2.09)x10{sup -5} mSv, and (0.056 {+-}0.01) x10{sup -5} to (0.239{+-}0.01)x10{sup -5} mSv, respectively. This indicated that the effects of dissolved radon on the bronchial epithelium are much than on the stomach and whole body. (authors)

  2. Radon daughter dosimeter

    International Nuclear Information System (INIS)

    Durkin, J.

    1977-01-01

    This patent describes a portable radon daughter dosimeter unit used to measure radon gas alpha daughters in ambient air. These measurements can then be related to preselected preestablished standards contained in a remote central readout unit. The dosimeter unit is adapted to be worn by an operator in areas having alpha particle radiation such as in uranium mines. Within the dosimeter is a detector head housing having a filter head and a solid state surface barrier radiation detector; an air pump to get air to the detector head; a self contained portable power supply for the unit; and electronic circuitry to process detected charged electrons from the detector head to convert and count their pulses representatives of two alpha radon emitter daughters. These counted pulses are in binary form and are sent to a readout unit where a numerical readout displays the result in terms of working level-hours

  3. Radon daughter dosimeter

    International Nuclear Information System (INIS)

    Durkin, J.

    1977-01-01

    A portable radon daughter dosimeter unit used to measure Radon gas alpha daughters in ambient air is described. These measurements can then be related to preselected preestablished standards contained in a remote central readout unit. The dosimeter unit is adapted to be worn by an operator in areas having alpha particle radiation such as uranium mines. Within the dosimeter is a detector head housing having a filter head and a solid state surface barrier radiation detector; an air pump to get air to the detector head; a self contained portable power supply for the unit; and electronic circuitry to process detected charged electrons from the detector head to convert and count their pulses representatives of two alpha radon emitter daughters. These counted pulses are in binary form and are sent to a readout unit where a numerical readout diplays the result in terms of working level-hours

  4. Scopingsreport Radon

    NARCIS (Netherlands)

    Blaauboer RO; Vaas LH; Hesse JM; Slooff W

    1989-01-01

    Dit scopingsrapport vormt een onderdeel van de voorbereiding tot het opstellen van het basisdocument radon. Het doel van dit rapport is het algemene kennisniveau van de deelnemers aan de scopingsbijeenkomst aangaande radon op eenzelfde peil te brengen en discussie- en beslispunten inzake de

  5. Groundwater electrical conductivity and soil radon gas monitoring for earthquake precursory studies in Koyna, India

    International Nuclear Information System (INIS)

    Reddy, D.V.; Nagabhushanam, P.

    2011-01-01

    Research highlights: → It is the first hydrochemical precursory study in the Koyna region, India. → Discrete conductivity measurements indicated progressive increase for 4 years. → Strong precursory EC change observed 40 h before the M 5.1 earthquake. → Precursory increase of soil Rn gas 20 days earlier than earthquakes M 4.7 and 5.1. → On-line monitoring of these parameters may help in earthquake forecast. - Abstract: Hourly monitoring of electrical conductivity (EC) of groundwater along with groundwater levels in the 210 m deep boreholes (specially drilled for pore pressure/earthquake studies) and soil Rn gas at 60 cm below ground level in real time, in the Koyna-Warna region (characterized by basaltic rocks, >1500 m thick, and dotted with several sets of fault systems), western India, provided strong precursory signatures in response to two earthquakes (M 4.7 on 14/11/09, and M 5.1 on 12/12/09) that occurred in the study region. The EC measured in Govare well water showed precursory perturbations about 40 h prior to the M 5.1 earthquake and continued further for about 20 h after the earthquake. In response to the M 4.7 earthquake, there were EC perturbations 8 days after the earthquake. In another well (Koyna) which is located 4 km north of Govare well, no precursory signatures were found for the M 4.7 earthquake, while for M 5.1 earthquake, post-seismic precursors were found 18 days after the earthquake. Increased porosity and reduced pressure head accompanied by mixing of a freshwater component from the top zone due to earthquakes are the suggested mechanisms responsible for the observed anomalies in EC. Another parameter, soil Rn gas showed relatively proportional strength signals corresponding to these two earthquakes. In both the cases, the pre-seismic increase in Rn concentration started about 20 days in advance. The co-seismic drop in Rn levels was less by 30% from its peak value for the M 4.7 earthquake and 50% for the M 5.1 earthquake. The Rn

  6. Gas-Filled Capillary Model

    International Nuclear Information System (INIS)

    Steinhauer, L. C.; Kimura, W. D.

    2006-01-01

    We have developed a 1-D, quasi-steady-state numerical model for a gas-filled capillary discharge that is designed to aid in selecting the optimum capillary radius in order to guide a laser beam with the required intensity through the capillary. The model also includes the option for an external solenoid B-field around the capillary, which increases the depth of the parabolic density channel in the capillary, thereby allowing for propagation of smaller laser beam waists. The model has been used to select the parameters for gas-filled capillaries to be utilized during the Staged Electron Laser Acceleration -- Laser Wakefield (STELLA-LW) experiment

  7. Project Radon

    International Nuclear Information System (INIS)

    Ekholm, S.

    1988-01-01

    The project started in March 1987. The objective is to perform radon monitoring in 2000 dwellings occupied by people employed by State Power Board and to continue to contribute to the development of radon filters. The project participates in developing methods for radon measurement and decontamination and in adapting the methods to large scale application. About 400 so called radon trace measurements (coarse measurement) and about 10 action measurements (decontamination measurement) have been made so far. Experience shows that methods are fully applicable and that the decontamination measures recommended give perfectly satisfactory results. It is also established that most of the houses with high radon levels have poor ventilation Many of them suffer from moisture and mould problems. The work planned for 1988 and 1989 will in addition to measurements be directed towards improvement of the measuring methods. An activity catalogue will be prepared in cooperation with ventilation enterprises. (O.S.)

  8. Radon entry into buildings: Effects of atmospheric pressure fluctuations and building structural factors

    International Nuclear Information System (INIS)

    Robinson, A.L.

    1996-05-01

    An improved understanding of the factors that control radon entry into buildings is needed in order to reduce the public health risks caused by exposure to indoor radon. This dissertation examines three issues associated with radon entry into buildings: (1) the influence of a subslab gravel layer and the size of the openings between the soil and the building interior on radon entry; (2) the effect of atmospheric pressure fluctuations on radon entry; and (3) the development and validation of mathematical models which simulate radon and soil-gas entry into houses. Experiments were conducted using two experimental basements to examine the influence of a subslab gravel layer on advective radon entry driven by steady indoor-outdoor pressure differences. These basement structures are identical except that in one the floor slab lies directly on native soil whereas in the other the slab lies on a high-permeability gravel layer. The measurements indicate that a high permeability subslab gravel layer increases the advective radon entry rate into the structure by as much as a factor of 30. The magnitude of the enhancement caused by the subslab gravel layer depends on the area of the openings in the structure floor; the smaller the area of these openings the larger the enhancement in the radon entry rate caused by the subslab gravel layer. A three-dimensional, finite-difference model correctly predicts the effect of a subslab gravel layer and open area configuration on advective radon entry driven by steady indoor-outdoor pressure differences; however, the model underpredicts the absolute entry rate into each structure by a factor of 1.5

  9. Radon entry into buildings: Effects of atmospheric pressure fluctuations and building structural factors

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Allen Lantham [Univ. of California, Berkeley, CA (United States). Dept. of Mechanical Engineering

    1996-05-01

    An improved understanding of the factors that control radon entry into buildings is needed in order to reduce the public health risks caused by exposure to indoor radon. This dissertation examines three issues associated with radon entry into buildings: (1) the influence of a subslab gravel layer and the size of the openings between the soil and the building interior on radon entry; (2) the effect of atmospheric pressure fluctuations on radon entry; and (3) the development and validation of mathematical models which simulate radon and soil-gas entry into houses. Experiments were conducted using two experimental basements to examine the influence of a subslab gravel layer on advective radon entry driven by steady indoor-outdoor pressure differences. These basement structures are identical except that in one the floor slab lies directly on native soil whereas in the other the slab lies on a high-permeability gravel layer. The measurements indicate that a high permeability subslab gravel layer increases the advective radon entry rate into the structure by as much as a factor of 30. The magnitude of the enhancement caused by the subslab gravel layer depends on the area of the openings in the structure floor; the smaller the area of these openings the larger the enhancement in the radon entry rate caused by the subslab gravel layer. A three-dimensional, finite-difference model correctly predicts the effect of a subslab gravel layer and open area configuration on advective radon entry driven by steady indoor-outdoor pressure differences; however, the model underpredicts the absolute entry rate into each structure by a factor of 1.5.

  10. Radon investigations - Soil and commercial projects

    International Nuclear Information System (INIS)

    Goodwin, R.W.

    1987-01-01

    The liability issues of radon exposure have prompted potential purchasers of vacant land for commercial/industrial development, and commercial landlords, renting large commercial buildings, to determine the radon gas levels at such sites. This paper deals with both pre-construction sites subject to freezing conditions and to large commercial structures. A correlation of radon gas levels within a commercial building and a sister pre-construction site confirms the validity of using activated charcoal canisters as a cost effective means to combating radon in large structures

  11. Radon measurements in some areas in Bangladesh

    International Nuclear Information System (INIS)

    Hamid Khan, M.A.; Chowdhury, M.S.

    2008-01-01

    A survey of radon level measurements using CR-39 has been carried out in some of urban and rural residential areas and one gas explosion area in Bangladesh. The lowest level of radon concentration was found to be 49Bqm -3 inside a hospital in Cox's Bazar district and the highest level was found to be 835Bqm -3 inside a mud-made old residential house in Sylhet city. It was observed that old residential houses were found to have higher levels of radon concentrations compared to newly built houses. The radon level at the gas explosion area at Magurchara in Moulvibazar district was found to be 408±98Bqm -3

  12. Radon Research Program, FY 1992

    International Nuclear Information System (INIS)

    1993-04-01

    The United States Department of Energy, Office of Health and Environmental Research (DOE/OHER) is the principal federal agency conducting basic research related to indoor radon. The scientific information being sought in this program encompasses research designed to determine radon availability and transport outdoors, modeling transport into and within buildings, physics and chemistry of radon and radon progeny, dose response relationships, lung cancer risk, and mechanisms of radon carcinogenesis. There still remains a significant number of uncertainties in the currently available knowledge that is used to estimate lung cancer risk from exposure to environmental levels of radon and its progeny. The main goal of the DOE/OHER Radon Research Program is to develop information to reduce these uncertainties and thereby provide an improved health risk estimate of exposure to radon and its progeny and to identify and understand biological mechanisms of lung cancer development and required copollutants at low levels of exposure. Information useful in radon control strategies is also provided by the basic science undertaken in this program

  13. Human exposure to indoor radon: A survey in the region of Guarda, Portugal

    International Nuclear Information System (INIS)

    Louro, A.; Peralta, L.; Soares, S.; Pereira, A.; Cunha, G.; Belchior, A.; Ferreira, L.; Gil, O. M.; Louro, H.; Pinto, P.; Rodrigues, A. S.; Silva, M. J.; Teles, P.

    2013-01-01

    Radon ( 222 Rn) is a radioactive gas, abundant in granitic areas, such as the city of Guarda at the northeast of Portugal. This gas is recognised as a carcinogenic agent, being appointed by the World Health Organization as the second leading cause of lung cancer after tobacco smoke. Therefore, the knowledge of radon concentrations inside the houses (where people stay longer) is important from the point of view of radiological protection. The main goal of this study was to assess the radon concentration in an area previously identified with a potentially high level of residential radon. The radon concentration was measured using CR-39 detectors, exposed for a period of 2 months in 185 dwellings in the Guarda region. The radon concentration in studied dwellings, ranged between 75 and 7640 Bq m -3 , with a geometric mean of 640 Bq m -3 and an arithmetic mean of 1078 Bq m -3 . Based on a local winter-summer radon concentration variation model, these values would correspond to an annual average concentration of 860 Bq m -3 . Several factors contribute to this large dispersion, the main one being the exact location of housing construction in relation to the geochemical nature of the soil and others the predominant building material and ventilation. Based on the obtained results an average annual effective dose of 15 mSv y -1 is estimated, well above the average previously estimated for Portugal. (authors)

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

    International Nuclear Information System (INIS)

    Cheng, Y.S.; Chen, B.T.

    1990-01-01

    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 μm 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 212 Pb. The deposition rates of the particles and radon progeny ( 212 Pb) in the chamber were determined by monitoring the concentration decay of the aerosol as a function of time

  15. Development of a predictive methodology for identifying high radon exhalation potential areas; Mise au point d'une methodologie predictive des zones a fort potentiel d'exhalation du radon

    Energy Technology Data Exchange (ETDEWEB)

    Ielsch, G

    2001-07-01

    Radon 222 is a radioactive natural gas originating from the decay of radium 226 which itself originates from the decay of uranium 23 8 naturally present in rocks and soil. Inhalation of radon gas and its decay products is a potential health risk for man. Radon can accumulate in confined environments such as buildings, and is responsible for one third of the total radiological exposure of the general public to radiation. The problem of how to manage this risk then arises. The main difficulty encountered is due to the large variability of exposure to radon across the country. A prediction needs to be made of areas with the highest density of buildings with high radon levels. Exposure to radon varies depending on the degree of confinement of the habitat, the lifestyle of the occupants and particularly emission of radon from the surface of the soil on which the building is built. The purpose of this thesis is to elaborate a methodology for determining areas presenting a high potential for radon exhalation at the surface of the soil. The methodology adopted is based on quantification of radon exhalation at the surface, starting from a precise characterization of the main local geological and pedological parameters that control the radon source and its transport to the ground/atmosphere interface. The methodology proposed is innovative in that it combines a cartographic analysis, parameters integrated into a Geographic Information system, and a simplified model for vertical transport of radon by diffusion through pores in the soil. This methodology has been validated on two typical areas, in different geological contexts, and gives forecasts that generally agree with field observations. This makes it possible to identify areas with a high exhalation potential within a range of a few square kilometers. (author)

  16. Development of a predictive methodology for identifying high radon exhalation potential areas; Mise au point d'une methodologie predictive des zones a fort potentiel d'exhalation du radon

    Energy Technology Data Exchange (ETDEWEB)

    Ielsch, G

    2001-07-01

    Radon 222 is a radioactive natural gas originating from the decay of radium 226 which itself originates from the decay of uranium 23 8 naturally present in rocks and soil. Inhalation of radon gas and its decay products is a potential health risk for man. Radon can accumulate in confined environments such as buildings, and is responsible for one third of the total radiological exposure of the general public to radiation. The problem of how to manage this risk then arises. The main difficulty encountered is due to the large variability of exposure to radon across the country. A prediction needs to be made of areas with the highest density of buildings with high radon levels. Exposure to radon varies depending on the degree of confinement of the habitat, the lifestyle of the occupants and particularly emission of radon from the surface of the soil on which the building is built. The purpose of this thesis is to elaborate a methodology for determining areas presenting a high potential for radon exhalation at the surface of the soil. The methodology adopted is based on quantification of radon exhalation at the surface, starting from a precise characterization of the main local geological and pedological parameters that control the radon source and its transport to the ground/atmosphere interface. The methodology proposed is innovative in that it combines a cartographic analysis, parameters integrated into a Geographic Information system, and a simplified model for vertical transport of radon by diffusion through pores in the soil. This methodology has been validated on two typical areas, in different geological contexts, and gives forecasts that generally agree with field observations. This makes it possible to identify areas with a high exhalation potential within a range of a few square kilometers. (author)

  17. Radon emanation rate in construction materials and various design of house

    International Nuclear Information System (INIS)

    Ahmad Asyraf Osman

    2012-01-01

    Indoor air quality are important factors that need to be addressed because it can affect the health and comfort of occupants in it. Among the major sources of indoor air pollution are radon gas. Radiological risk due to radon gas due to its intake into the human body is the major cause of lung cancer. This study was conducted to determine the radon emanation rate that occurs naturally in the building materials and its contains in several kinds of house. Construction materials studied are sand, gravel, cement and bricks. Terrace houses, double storey terrace houses, flats and wooden houses were studied in radon emanation in various types of houses. Radon emanation rates in building materials in a variety of home and the home measured using Sun Nuclear radon monitor (model 1029) and radon gas concentrations are measured in units of Bq m -3 . From the results, granites have recorded the highest radon emissions that is 2.67 μBq kg -1 s -1 , followed by sand with 2.53 μBq kg -1 s -1 . The bricks emission rate were recorded was 2.47 μBq kg -1 s -1 , while Cement recorded the lowest with only 1.46 μBq kg -1 s -1 . In study of radon in a variety of home, the results showed that the single storey terrace houses recorded the highest reading of 25.67 ± 4.96 Bq m -3 . First level Double storey terrace houses recorded 23.24 ± 3.72 Bq m -3 compared with a second level of two-storey terrace house which recorded emission rate of 16.43 ± 2.53 Bq m -3 . Flats were recorded the second lowest with only 13.07 ± 2.38 Bq m -3 . House that recorded the lowest reading was wooden houses that recorded 9.53 ± 1.96 Bq m -3 . (author)

  18. An experimental two-stage rat model of lung carcinoma initiated by radon exposure

    International Nuclear Information System (INIS)

    Poncy, J.L.; Laroque, P.; Fritsch, P.; Monchaux, G.; Masse, R.; Chameaud, J.

    1992-01-01

    We present the results of a two-stage biological model of lung carcinogenesis in rats. The histogenesis of these tumors was examined, and DNA content of lung cells was measured by flow cytometry during the evolving neoplastic stage. Tumors were induced in rat lungs after radon inhalation (1600 WLM) followed by a promoter treatment; six intramuscular injections of 5,6-benzoflavone (25 mg/kg of body weight/injection) every 2 wk. Less than 3 mo after the first injection of benzoflavone, squamous cell carcinoma was observed in the lungs of all rats exposed to radon. The preneoplastic lesions gradually developed as follows: hyperplastic bronchiolar-type cells migrated to the alveoli from cells that proliferated in bronchioles and alveolar ducts; initial lesions were observed in almost all respiratory bronchioles. From some hyperplasias, epidermoid metaplasias arose distally, forming nodular epidermoid lesions in alveoli, which progressed to form squamous papilloma and, finally, epidermoid carcinomas. The histogenesis of these experimentally induced epidermoid carcinomas showed the bronchioloalveolar origin of the tumor. This factor must be considered when comparing these with human lesions; in humans, lung epidermoid carcinomas are thought to arise mainly in the first bronchial generations. The labeling index of pulmonary tissue after incorporation of 3 H-thymidine by the cells was 0.2% in control rats. This index reached a value of 1 to 2% in the hyperplastic area of the bronchioles and 10 to 15% in epidermoid nodules and epidermoid tumors, respectively. DNA cytometric analysis was performed on cell suspensions obtained after enzymatic treatment of paraffin sections of lungs from rats sacrificed during different stags of neoplastic transformations. Data showed the early appearance of a triploid cell population that grew during the evolution of nodular epidermoid lesions to epidermoid carcinomas

  19. Radon Gas in Ireland Joint Position Statement by the Radiological Protection Institute of Ireland and the Health Service Executive

    International Nuclear Information System (INIS)

    Part, A.M.; Colgan, P.A.; Fenton, D.; Kelly, I.; Long, S.; O'Mahony, M.; Pollard, D.

    2010-04-01

    This position statement is written by the Health Service Executive and the Radiological Protection Institute of Ireland with a view to forming and influencing policy in this area. It provides a summary of the health risks associated with radon exposure in Ireland and the steps that can be taken to reduce those risks. It outlines suggested ongoing work to reduce both the population dose from radon and the individual dose to those most at risk and considers future work needed to improve national policy to achieve these objectives

  20. Radon risk in the house

    International Nuclear Information System (INIS)

    Bressa, G.

    2001-01-01

    Radon was discovered in 1900, but its potential dangerousness for man was fully understood only in 1950. Being a radioactive natural gas - and therefore particularly dangerous - radon results from the long decay chain of radionuclides, such as thorium and radium. Some igneous rocks (granite, tufa and lava) as well as coal are considered to be the main sources of this radionuclide. A number of epidemiologic studies have shown the carcinogenicity of this element, particularly among miners and workers subjected to high level exposure in confined spaces such as basements, garages, cellars, etc. There are, however, some techniques to remove radon in order to reduce exposure to minimum values [it

  1. Radon as an earthquake precursor

    International Nuclear Information System (INIS)

    Planinic, J.; Radolic, V.; Vukovic, B.

    2004-01-01

    Radon concentrations in soil gas were continuously measured by the LR-115 nuclear track detectors during a four-year period. Seismic activities, as well as barometric pressure, rainfall and air temperature were also observed. The influence of meteorological parameters on temporal radon variations was investigated, and a respective equation of the multiple regression was derived. The earthquakes with magnitude ≥3 at epicentral distances ≤200 km were recognized by means of radon anomaly. Empirical equations between earthquake magnitude, epicentral distance and precursor time were examined, and respective constants were determined

  2. Radon as an earthquake precursor

    Energy Technology Data Exchange (ETDEWEB)

    Planinic, J. E-mail: planinic@pedos.hr; Radolic, V.; Vukovic, B

    2004-09-11

    Radon concentrations in soil gas were continuously measured by the LR-115 nuclear track detectors during a four-year period. Seismic activities, as well as barometric pressure, rainfall and air temperature were also observed. The influence of meteorological parameters on temporal radon variations was investigated, and a respective equation of the multiple regression was derived. The earthquakes with magnitude {>=}3 at epicentral distances {<=}200 km were recognized by means of radon anomaly. Empirical equations between earthquake magnitude, epicentral distance and precursor time were examined, and respective constants were determined.

  3. Radon gas inside historical buildings in the city of Cordoba; Gas {sup 222}Rn en construcciones historicas de la ciudad de Cordoba

    Energy Technology Data Exchange (ETDEWEB)

    Perez, R; Germanier, A; Rubio, M [CEPROCOR, Cordoba (Argentina); Sbarato, D; Zappino, R [Observatorio Ambiental de la Municipalidad de Cordoba, Cordoba (Argentina)

    1998-07-01

    Full text: In this work measurements of the Radon ({sup 222}Rn) concentration in the inside of historical buildings which date back to the end of the 17th and the beginning of the 18th Centuries have been carried out in the city of Cordoba (Argentina). Meteorological factors such as room temperature and atmospheric pressure have not shown to affect, to a great extent, the results obtained. By comparing the concentration of {sup 222}Rn in environments at different levels we inferred that the soil underlying the buildings does not represent an important source of {sup 222}Rn. The main occurrence of the element was found in room walls, which shows that local building materials are an important source of {sup 222}Rn. Among the materials used in these buildings are granitic rocks, and to a lesser extent, lime, sand and marble. The {sup 222}Rn concentrations recorded in some of the rooms surveyed reach values which are close to the minimum intervene level set by international standards in 4pCi/l. The study of the effects of ventilation in the concentration of {sup 222}Rn allows us to conclude that its values decrease to accepted levels by means of a natural and efficient ventilation of the rooms. (author) [Spanish] Texto completo: En este trabajo se han realizado mediciones de la concentracion de radon (radon 222) en el interior de edificios de la ciudad de Cordoba que datan de finales del siglo XVII y comienzos del siglo XVIII. Las concentraciones de radon 222 se determinaron con un detector pasivo Radon Monitor 05-418, marca Victoreen. El mismo consta de una camara de difusion electrostatica y un detector de estado solido (Si) de juntura difundida. No se observo, en los resultados obtenidos, influencias causadas por factores meteorologicos como la temperatura ambiente y la presion atmosferica. Por comparacion de la concentracion de radon 222 en ambientes ubicados en distintas plantas se dedujo que el suelo subyacente bajo los edificios representa una fuente secundaria

  4. Concept for a primary Romanian radon standard

    International Nuclear Information System (INIS)

    Sahagia, M.; Stanga, D.; Waetjen, A.C.; Luca, A.; Toro, L.; Varlam, C.; Cassette, P.

    2008-01-01

    The paper presents the concept of a complex system, aimed to assure the traceability of 222 Rn measurements, from the absolute (primary) standardization to the preparation and delivery of secondary standards, gas vials. The system will contain a solid 226 Ra source, a gas radon circuit, connections with a liquid scintillator vial and with glass vials. The absolute standardization of the 222 Rn, in equilibrium with all the short half life daughters, will be performed by the method of the Liquid Scintillation Counting (LSC). The system, and method, will allow our laboratory to take part in future international 222 Rn comparisons. The transfer of activity unit from the primary to the secondary standardization will be performed by the preparation of vials with 222 Rn gas, comparative measurements by LSC and a GeHP gamma-ray spectrometry system, or a well type NaI(Tl) crystal, and their link. The secondary standards will be used for the calibration of measurement instruments, for assurance of controlled radon atmosphere in 'radon chambers', and for the validation of some calculation models for various detectors efficiency. The range of activities for secondary standards is in agreement with the national measurement necessities. (author)

  5. Models for retrospective quantification of indoor radon exposure in case-control studies

    International Nuclear Information System (INIS)

    Gerken, M.; Kreienbrock, L.; Wellmann, J.; Kreuzer, M.; Wichmann, H.E.

    2000-01-01

    In epidemiologic studies on lung cancer risk due to indoor radon the quantification of individual radon exposure over a long time period is one of the main issues. Therefore, radon measurements in one or more dwellings, which in total have been inhabited by the participants for a sufficient time-period, are necessary as well as consideration of changes of building characteristics and ventilation habits, which influence radon concentration. Given data on 1-y alpha-track measurements and personal information from 6,000 participants of case-control studies in West and East Germany, and improved method is developed to assess individual radon exposure histories. Times spent in different rooms of the dwelling, which are known from a personal questionnaire, are taken into account. The time spent outside the house varies substantially among the participants. Therefore, assuming a substantially lower radon exposure outside the dwelling, the residence time constitutes an important aspect of total radon exposure. By means of an analysis of variance, important determinants of indoor radon are identified, namely constant conditions such as type of house, type of construction, year of construction, floor and type of basement, and changeable conditions such as heating system, window insulation, and airing habits. A correction of measurements in former dwellings by factors derived from the analysis is applied if current living conditions differ from those of the participants at the time when they were living in the particular dwellings. In rare cases the adjustment for changes leads to a correction of the measurements with a factor of about 1.4, but a reduction of 5% on average only. Exposure assessment can be improved by considering time at home and changes of building and ventilation conditions that affect radon concentration. The major concern that changes in ventilation habits and building conditions lead to substantial errors in exposure assessment cannot be confirmed in the

  6. Radon risk in the house; Il rischio radon nelle abitazioni

    Energy Technology Data Exchange (ETDEWEB)

    Bressa, G. [Padua Univ., Padua (Italy). Dipt. di Farmacologia e Anestesiologia, Lab. di Tossicologia

    2001-04-01

    Radon was discovered in 1900, but its potential dangerousness for man was fully understood only in 1950. Being a radioactive natural gas - and therefore particularly dangerous - radon results from the long decay chain of radionuclides, such as thorium and radium. Some igneous rocks (granite, tufa and lava) as well as coal are considered to be the main sources of this radionuclide. A number of epidemiologic studies have shown the carcinogenicity of this element, particularly among miners and workers subjected to high level exposure in confined spaces such as basements, garages, cellars, etc. There are, however, some techniques to remove radon in order to reduce exposure to minimum values. [Italian] Il radon fu scoperto nel 1900, ma solo nel 1950 si comprese la sua potenziale pericolosita' per l'uomo. Il radon e' particolarmente pericoloso essendo un gas naturale radioattivo. Esso proviene dalla lunga catena di decadimento di radionuclidi come il torio e di radio. Sorgenti di tale radionuclide sono da considerarsi principalmente alcune rocce ignee (graniti, tufi e lave) e il carbone. Diversi studi epidemiologici hanno evidenziato la cancerogenicita' di tale elemento, specie tra i minatori e soggetti esposti ad alti livelli in ambienti confinati quali scantinati, garage sotterranei, ecc.. Esistono comunque tecniche di intervento per la rimozione del gas radon in modo tale da ridurre l'esposizione a valori minimi.

  7. Submarine groundwater discharge to a small estuary estimated from radon and salinity measurements and a box model

    Directory of Open Access Journals (Sweden)

    J. Crusius

    2005-01-01

    Full Text Available Submarine groundwater discharge was quantified by a variety of methods for a 4-day period during the early summer of 2004, in Salt Pond, adjacent to Nauset Marsh, on Cape Cod, USA. Discharge estimates based on radon and salinity took advantage of the presence of the narrow channel connecting Salt Pond to Nauset Marsh, which allowed constructing whole-pond mass balances as water flowed in and out due to tidal fluctuations. The data suggest that less than one quarter of the discharge in the vicinity of Salt Pond happened within the pond itself, while three quarters or more of the discharge occurred immediately seaward of the pond, either in the channel or in adjacent regions of Nauset Marsh. Much of this discharge, which maintains high radon activities and low salinity, is carried into the pond during each incoming tide. A box model was used as an aid to understand both the rates and the locations of discharge in the vicinity of Salt Pond. The model achieves a reasonable fit to both the salinity and radon data assuming submarine groundwater discharge is fresh and that most of it occurs either in the channel or in adjacent regions of Nauset Marsh. Salinity and radon data, together with seepage meter results, do not rule out discharge of saline groundwater, but suggest either that the saline discharge is at most comparable in volume to the fresh discharge or that it is depleted in radon. The estimated rate of fresh groundwater discharge in the vicinity of Salt Pond is 3000-7000 m3 d-1. This groundwater flux estimated from the radon and salinity data is comparable to a value of 3200-4500 m3 d-1 predicted by a recent hydrologic model (Masterson, 2004; Colman and Masterson, 2004, although the model predicts this rate of discharge to the pond whereas our data suggest most of the groundwater bypasses the pond prior to discharge. Additional work is needed to determine if the measured rate of discharge is representative of the long-term average, and to

  8. CASCADER: An m-chain gas-phase radionuclide transport and fate model

    International Nuclear Information System (INIS)

    Cawlfield, D.E.; Been, K.B.; Emer, D.F.; Lindstrom, F.T.; Shott, G.J.

    1993-06-01

    Chemicals and radionuclides move either in the gas-phase, liquid-phase, or both phases in soils. They may be acted upon by either biological or abiotic processes through advection and/or diffusion. Furthermore, parent and daughter radionuclides may decay as they are transported in the soil. This is volume two to the CASCADER series, titled CASCADR8. It embodies the concepts presented in volume one of this series. To properly understand how the CASCADR8 model works, the reader should read volume one first. This volume presents the input and output file structure for CASCADR8, and a set of realistic scenarios for buried sources of radon gas

  9. CASCADER: An M-chain gas-phase radionuclide transport and fate model

    International Nuclear Information System (INIS)

    Cawlfield, D.E.; Emer, D.F.; Lindstrom, F.T.; Shott, G.J.

    1993-09-01

    Chemicals and radionuclides move either in the gas-phase, liquid-phase, or both phases in soils. They may be acted upon by either biological or abiotic processes through advection and/or dispersion. Additionally during the transport of parent and daughter radionuclides in soil, radionuclide decay may occur. This version of CASCADER called CASCADR9 starts with the concepts presented in volumes one and three of this series. For a proper understanding of how the model works, the reader should read volume one first. Also presented in this volume is a set of realistic scenarios for buried sources of radon gas, and the input and output file structure for CASCADER9

  10. CONTRIBUTION OF RADON FLOWS AND RADON SOURCES TO THE RADON CONCENTRATION IN A DWELLING

    NARCIS (Netherlands)

    DEMEIJER, RJ; STOOP, P; PUT, LW

    1992-01-01

    In this paper a model is presented for analysis of the radon concentrations in a compartment in terms of contributions from transport by flows of air between compartments and from radon sources in the compartment. Measurements were made to study the effect of increased natural ventilation of the

  11. Perumusan Model Moneter Berdasarkan Perilaku Gas Ideal

    Directory of Open Access Journals (Sweden)

    Rachmad Resmiyanto

    2014-04-01

    Full Text Available Telah disusun sebuah model moneter yang berdasarkan perilaku gas ideal. Model disusun dengan menggunakan metode kias/analogi. Model moneter gas ideal mengiaskan jumlah uang beredar dengan volume gas, daya beli dengan tekanan gas dan produksi barang dengan suhu gas. Model ini memiliki formulasi yang berbeda dengan Teori Kuantitas Uang (Quantity Theory of Money yang dicetuskan oleh Irving Fisher, model moneter Marshal-Pigou dari Cambridge serta model moneter ala Keynes. Selama ini 3 model tersebut dianggap sebagai model yang mapan dalam teori moneter pada buku-buku teks ekonomi. Model moneter gas ideal dapat menjadi cara pandang baru terhadap sistem moneter.

  12. Modeling of the behavior of radon and its decay products in dwelling, and experimental validation of the model

    International Nuclear Information System (INIS)

    Gouronnec, A.M.; Robe, M.C.; Montassier, N.; Boulaud, D.

    1993-01-01

    A model of the type written by Jacobi is adapted to indoor air to describe the behavior of radon and its decay products within a dwelling, and is then adapted to a system of several stories. To start the validation of the model, computed data are compared with field measurements. The first observations we may make are that the model is consistent with data we have. But it is important to develop an exhaustive set of experimental data and to obtain as faithful as possible a representation of the mean situation; this specially concerns the ventilation rate of the enclosure and the rate of attachment to airborne particles. Further work should also be done to model deposition on surfaces. (orig.). (6 refs., 4 tabs.)

  13. Study and treatment of situations implying radon

    International Nuclear Information System (INIS)

    Robe, M.Ch.

    2005-01-01

    The radon is a radioactive gas with a natural origin. It comes from a disintegration of uranium and radium present in the soils. It comes from granitic and volcanic subsoils. The radon can accumulate in buildings. It is the principal source of natural exposure and the second one after medical exposures. It is the only one source of radiations on which man is susceptible to act. Ventilation and airtightness are solutions to reduce radon concentration. (N.C.)

  14. Radon depth migration

    International Nuclear Information System (INIS)

    Hildebrand, S.T.; Carroll, R.J.

    1993-01-01

    A depth migration method is presented that used Radon-transformed common-source seismograms as input. It is shown that the Radon depth migration method can be extended to spatially varying velocity depth models by using asymptotic ray theory (ART) to construct wavefield continuation operators. These operators downward continue an incident receiver-array plane wave and an assumed point-source wavefield into the subsurface. The migration velocity model is constrain to have longer characteristic wavelengths than the dominant source wavelength such that the ART approximations for the continuation operators are valid. This method is used successfully to migrate two synthetic data examples: (1) a point diffractor, and (2) a dipping layer and syncline interface model. It is shown that the Radon migration method has a computational advantage over the standard Kirchhoff migration method in that fewer rays are computed in a main memory implementation

  15. Evaluation of indoor radon equilibrium factor using CFD modeling and resulting annual effective dose

    Science.gov (United States)

    Rabi, R.; Oufni, L.

    2018-04-01

    The equilibrium factor is an important parameter for reasonably estimating the population dose from radon. However, the equilibrium factor value depended mainly on the ventilation rate and the meteorological factors. Therefore, this study focuses on investigating numerically the influence of the ventilation rate, temperature and humidity on equilibrium factor between radon and its progeny. The numerical results showed that ventilation rate, temperature and humidity have significant impacts on indoor equilibrium factor. The variations of equilibrium factor with the ventilation, temperature and relative humidity are discussed. Moreover, the committed equivalent doses due to 218Po and 214Po radon short-lived progeny were evaluated in different tissues of the respiratory tract of the members of the public from the inhalation of indoor air. The annual effective dose due to radon short lived progeny from the inhalation of indoor air by the members of the public was investigated.

  16. Radon levels and transport parameters in Atlantic Forest soils

    International Nuclear Information System (INIS)

    Farias, E.E.G. de; Silva Neto, P.C. da; Souza, E.M. de; De Franca, E.J.; Hazin, C.A.

    2016-01-01

    In natural forest soils, the radon transport processes can be significantly intensified due to the contribution of living organism activities to soil porosity. In this paper, the first results of the radon concentrations were obtained for soil gas from the Atlantic Forest, particularly in the Refugio Ecologico Charles Darwin, Brazil. The estimation of permeability and radon exhalation rate were carried out in this conservation unit. For forested soils, radon concentrations as high as 40 kBq m -3 were found. Based on the radon concentrations and on the permeability parameter, the results indicated considerable radon hazard for human occupation in the neighborhood. (author)

  17. Investigation of the exposure to radon and progeny in the thermal spas of Loutraki (Attica-Greece): Results from measurements and modelling

    International Nuclear Information System (INIS)

    Nikolopoulos, Dimitrios; Vogiannis, Efstratios; Petraki, Ermioni; Zisos, Athanasios; Louizi, Anna

    2010-01-01

    Radon and progeny ( 218 Po, 214 Pb, 214 Bi and 214 Po) in thermal spas are well known radioactive pollutants identified for additional radiation burden of patients due to the activity concentration peaks which appear during bath treatment or due to drinking of waters of high radon content. This burden affects additionally the working personnel of the spas. The present paper has focused on the thermal spas of Loutraki (Attica-Greece). The aim was the investigation of the health impact for patients and working personnel due to radon and progeny. Attention has been paid to radon and progeny transient concentration peaks (for bath treatment) and to radon of thermal waters (both for bath treatment and drinking therapy). Designed experiments have been carried out, which included radon and progeny activity concentration measurements in thermal waters and ambient air. Additionally, published models for description of radon and progeny transient concentration peaks were employed. The models were based on physicochemical processes involved and employed non linear first order derivative mass balance differential equations which were solved numerically with the aid of specially developed computer codes. The collected measurements were analysed incorporating these models. Results were checked via non linear statistical tests. Predictions and measurements were found in close agreement. Non linear parameters were estimated. The models were employed for dosimetric estimations of patients and working personnel. The effective doses of patients receiving bath treatment were found low but not negligible. The corresponding doses to patients receiving potable treatment were found high but below the proposed international limits. It was found that the working personnel are exposed to considerable effective doses, however well below the acceptable limits for workers. It was concluded that treatment and working in the Loutraki spas leads to intense variations of radon and progeny and

  18. Modeling of lung cancer risk due to radon exhalation of granite stone in dwelling houses

    Directory of Open Access Journals (Sweden)

    Akbar Abbasi

    2017-01-01

    Conclusions: The estimated numbers of lung cancer deaths attributable to indoor radon due to granite stones in 2013 were 145 (3.33% and 103 (2.37% for poor and normal ventilation systems, respectively. According to our estimations, the values of 3.33% and 2.37% of lung cancer deaths in 2013 are attributed to radon exhalation of granite stones with poor and normal ventilation systems, respectively.

  19. The use of track registration detectors to reconstruct contemporary and historical airborne radon ( sup 2 sup 2 sup 2 Rn) and radon progeny concentrations for a radon-lung cancer epidemiologic study

    CERN Document Server

    Steck, D J

    1999-01-01

    Epidemiologic studies that investigate the relationship between radon and lung cancer require accurate estimates for the long-term average concentrations of radon progeny in dwellings. Year-to-year and home-to-home variations of radon in domestic environments pose serious difficulties for reconstructing an individual's long-term radon-related exposure. The use of contemporary radon gas concentrations as a surrogate for radon-related dose introduces additional uncertainty in dose assessment. Studies of glass exposed in radon chambers and in a home show that radon progeny deposited on, and implanted in, glass hold promise for reconstructing past radon concentrations in a variety of atmospheres. We developed an inexpensive track registration detector for the Iowa Radon Lung Cancer Study (IRLCS) that simultaneously measures contemporary airborne radon concentrations, surface deposited alpha activity density, and implanted sup 2 sup 1 sup 0 Po activity density. The implanted activity is used to reconstruct the cum...

  20. A fission gas release model

    Energy Technology Data Exchange (ETDEWEB)

    Denis, A; Piotrkowski, R [Argentine Atomic Energy Commission, Buenos Aires (Argentina)

    1997-08-01

    The hypothesis contained in the model developed in this work are as follows. The UO{sub 2} is considered as a collection of spherical grains. Nuclear reactions produce fission gases, mainly Xe and Kr, within the grains. Due to the very low solubility of these gases in UO{sub 2}, intragranular bubbles are formed, of a few nanometers is size. The bubbles are assumed to be immobile and to act as traps which capture gas atoms. Free atoms diffuse towards the grain boundaries, where they give origin to intergranular, lenticular bubbles, of the order of microns. The gas atoms in bubbles, either inter or intragranular, can re-enter the matrix through the mechanism of resolution induced by fission fragment impact. The amount of gas stored in intergranular bubbles grows up to a saturation value. Once saturation is reached, intergranular bubbles inter-connect and the gas in excess is released through different channels to the external surface of the fuel. The resolution of intergranular bubbles particularly affects the region of the grain adjacent to the grain boundary. During grain growth, the grain boundary traps the gas atoms, either free or in intragranular bubbles, contained in the swept volume. The grain boundary is considered as a perfect sink, i.e. the gas concentration is zero at that surface of the grain. Due to the spherical symmetry of the problem, the concentration gradient is null at the centre of the grain. The diffusion equation was solved using the implicit finite difference method. The initial solution was analytically obtained by the Laplace transform. The calculations were performed at different constant temperatures and were compared with experimental results. They show the asymptotic growth of the grain radius as a function of burnup, the gas distribution within the grain at every instant, the growth of the gas content at the grain boundary up to the saturation value and the fraction of gas released by the fuel element referred to the total gas generated

  1. Numerical modelling of local deposition patients, activity distributions and cellular hit probabilities of inhaled radon progenies in human airways

    International Nuclear Information System (INIS)

    Farkas, A.; Balashazy, I.; Szoeke, I.

    2003-01-01

    The general objective of our research is modelling the biophysical processes of the effects of inhaled radon progenies. This effort is related to the rejection or support of the linear no threshold (LNT) dose-effect hypothesis, which seems to be one of the most challenging tasks of current radiation protection. Our approximation and results may also serve as a useful tool for lung cancer models. In this study, deposition patterns, activity distributions and alpha-hit probabilities of inhaled radon progenies in the large airways of the human tracheobronchial tree are computed. The airflow fields and related particle deposition patterns strongly depend on the shape of airway geometry and breathing pattern. Computed deposition patterns of attached an unattached radon progenies are strongly inhomogeneous creating hot spots at the carinal regions and downstream of the inner sides of the daughter airways. The results suggest that in the vicinity of the carinal regions the multiple hit probabilities are quite high even at low average doses and increase exponentially in the low-dose range. Thus, even the so-called low doses may present high doses for large clusters of cells. The cell transformation probabilities are much higher in these regions and this phenomenon cannot be modeled with average burdens. (authors)

  2. Radiation levels of radon gas and its progeny in labor activities of mine interior and their effects in the Bolivian workers to 4000 m; Niveles de radiacion de gas radon y su progenie en actividades laborales de interior mina y sus efectos en los trabajadores bolivianos a 4000 m

    Energy Technology Data Exchange (ETDEWEB)

    Mamani M, R.; Claros J, J. T.; Vasquez A, R.; Chirveches, H. [Universidad Autonoma Tomas Frias, Villa Imperial de Potosi (Bolivia, Plurinational State of); Weyer, J.; Arnold, D., E-mail: raulm2k13@hotmail.com [Universidad Tecnica de Freiberg, Academia de Minas, Akademiestrabe 6, 09599 Freiberg (Georgia)

    2014-08-15

    The objectives of this study are guided to determine the radiation charges to those that the mining workers are exposed, in order to assume the appropriate protection measures. The first phase of this study begun in March of 2009, with the support of the Freiberg University (Germany), has been preceded of different scientific events and preparatory measurements in the Universidad Autonoma Tomas Frias (UATF) and Cerro Rico de Potosi. Experimentally the presence of radon gas has been quantified by means of measurements in 7 mines of Cerro Rico de Potosi, the COMSUR mines (today SINCHY WAYRA) and the state mining company COMIBOL (Oruro-Huanuni), using the measurement equipment Alpha Zaeller-2 (AZ-2). The Radon-222 that emerges of the interior of the fractured rocks and/or loose rocks, with more intensity if they are fresh, is inhaled by the mining worker. Considering the breathing parameters (1, 2 m{sup 3}/h), recommended by the ICRP, was observed that the miners breathing of the region is more bigger, due to the high effort that they develop in the work. Therefore, the calculation results of the concentration of the radiation activity of Radon, allow assuming that this is the causing of the damage to the lungs in the human body. Outdoor or in superficial tunnels, the impact is low or imperceptible. But when the process is verified to more depths in an underground mine, or not properly ventilated, the concentration as well as the exposure dose to the radiation of radon gas is increased to amazing values. Assuming that the maximum permissible limit is of 20 mSv, the study has established some values that exceeded this limit in the Bolivian mining, not controlled in this field until now. The component of the medical study, through exams: hematology and spirometric, notes that, by the complex inhalation of: air + powders + Radon gas and others in his working environment, contribute strongly to the generation of lethal illnesses in the mining worker, as the Poliglobulia

  3. Modelling the effect of non-uniform radon progeny activities on transformation frequencies in human bronchial airways

    International Nuclear Information System (INIS)

    Fakir, H.; Hofmann, W.; Aubineau-Laniece, I.

    2006-01-01

    The effects of radiological and morphological source heterogeneities in straight and Y-shaped bronchial airways on hit frequencies and Micro-dosimetric quantities in epithelial cells have been investigated previously. The goal of the present study is to relate these physical quantities to transformation frequencies in sensitive target cells and to radon-induced lung cancer risk. Based on an effect-specific track length model, computed linear energy transfer (LET) spectra were converted to corresponding transformation frequencies for different activity distributions and source - target configurations. Average transformation probabilities were considerably enhanced for radon progeny accumulations and target cells at the carinal ridge, relative to uniform activity distributions and target cells located along the curved and straight airway portions at the same exposure level. Although uncorrelated transformation probabilities produce a linear dose - effect relationship, correlated transformations first increase depending on the LET, but then decrease significantly when exceeding a defined number of hits or cumulative exposure level. (authors)

  4. Development of a portable radon detection system

    International Nuclear Information System (INIS)

    Allen, J.W.

    1976-09-01

    The presence of radon-222 in soil gas and ground water can indicate the existence of nearby uranium deposits even when heavy overburdens completely absorb the associated gamma radiation. Techniques to detect and measure radon have evolved during the past several years to the point where radon prospecting is routinely employed in a number of countries. A program to develop and field test a prototype system for measuring radon from soil gas and water is described. A prototype system employing a flow through scintillation detector was designed and constructed, utilizing standard commercial components, to provide a fieldworthy unit for testing the system concepts. Laboratory and preliminary field tests of this unit indicate that it can detect anomalous radon levels of less than 10 picoCuries per liter (pCi/l) in soil gas and ground water

  5. Study of different factors which can explain the radon exhalation potential of soils; Recherche de differents parametres caracterisant le potentiel d`exhalation en radon des sols

    Energy Technology Data Exchange (ETDEWEB)

    Demongeot, St

    1997-10-27

    Radon is a natural radioactive gas belonging to the Uranium-238 chain, which is present in the earth crust and produced by the disintegration of radium-226. It is considered as the major source of radiological exposure of man to natural radiation because it can accumulate in indoor atmosphere. So, this health risk must be take into account.The aim of this study is to find some tools in order to identify high radon level area. The first part of this study has consisted in measurement of radon emission from different not sufficient for the estimation of the radon exhalation potential in a given area. In the second part of this work, we have studied the variations of in situ radon concentration as a function of different geological and pedologic parameters of the site. With the results obtained, we have determined the data which have to be considered, and the methodology to be applied for the determination of the radon exhalation of a given area. Furthermore, by the mean of numerical simulations (TRACH Model), it was possible to know the scale of radon flux variation in a given point versus the hydric state of the ground and thus the permeability: these parameters are not easy to measure because of their variabilities with time. The methodology ESPERAS (EStimation du Potential d`Exhalation en Radon des Sols) developed during this work was applied first, at a local scale and then to greater area. The values estimated by this way are in a good agreement with the results of measurements. So, we can determine the areas which are affected by high radon levels. (author)

  6. Preseismic anomalies in soil-gas radon associated with 2016 M 6.6 Meinong earthquake, Southern Taiwan

    Directory of Open Access Journals (Sweden)

    Ching-Chou Fu

    2017-01-01

    Full Text Available Taiwan is tectonically situated in a terrain resulting from the oblique collision between the Philippine Sea plate and the continental margin of the Asiatic plate, with a continuous stress causing the density of strong-moderate earthquakes and regional active faults. The continuous time series of soil radon for earthquake studies have been recorded and some significant variations associated with strong earthquakes have been observed. Earthquake prediction is not still operative but these correlations should be added to the literature about seismo-geochemical transients associated to strong earthquakes. Rain-pore pressure related variations, crustal weakness at the studied faults system is consistent with the simultaneous radon anomalies observed. During the observations, a significant increase of soil radon concentrations was observed at Chunglun-T1 (CL-T1, Hsinhua (HH, Pingtung (PT, and Chihshan (CS stations approximately two weeks before the Meinong earthquake (ML = 6.6, 6 February 2016 in Southern Taiwan. The precursory changes in a multi-stations array may reflect the preparation stage of a large earthquake. Precursory signals are observed simultaneously and it can apply certain algorithms the approximate location and magnitude of the impending earthquake.

  7. How much radon is too much?

    International Nuclear Information System (INIS)

    Atwood, C.H.

    1991-01-01

    In recent years the concerns over human exposure to radon have become more pressing. This paper will attempt to explain the phenomenon of radon gas in the home, how it can be detected and measured and what are the maximum permissible exposure levels. The talk is aimed primarily at teachers who wish to introduce this material into their classroom discussions

  8. The radon gas at the context of legislation on the quality of internal air in buildings - the Portuguese experience; O gas radao no contexto da legislacao sobre a qualidade do ar interior em edificios - a experiencia portuguesa

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Paulo G.A.N.; Pereira, Alcides J.S.C.; Neves, Luis J.P.F., E-mail: ppinto@dct.uc.p, E-mail: apereira@dct.uc.p, E-mail: luisneves@dct.uc.p [Universidade de Coimbra (Portugal). Dept. de Ciencias da Terra. Instituto do Mar

    2011-10-26

    Radon gas has been recognized as an important environmental risk factor, especially when found in high concentrations inside buildings, and is currently classified by the World Health Organization as a carcinogen type 1. In this context, there is legislation in Portugal since 2006 that sets limits to its concentration in indoor air. The aim of this work was to synthesize the existing legislation with focus on the sampling and analysis. Some statistical data about the measurements obtained in the Natural Radioactivity Laboratory, of the Department of Earth Sciences, of the University of Coimbra are presented, and discussed in the context of the National Energy Certification of Buildings System

  9. Improved thomas formula for radon measurement

    International Nuclear Information System (INIS)

    Ji Changsong

    1991-06-01

    The FT 648 type portable absolute radon meter has been developed and the designing principle of this instrument is introduced. The absolute radon meter differs from relative radon meter. By using structure parameters, operating parameters and readout of this instrument, the radon content of measured gas is obtained directly without calibration in advance. Normally, the calibration is done by a standard radioactive gaseous source of which the radon concentration is known. The systematic error is removed by adding filter-efficiency Σ, α self-absorption correction β, energy spectrum correction S, geometric factor Ω of probe and gravity dropping correction factor G to the Thomas formula for radon measurement of two-filter method. The atmosphere radon content, which is given in hour-average, in Beijing area was measured by FT 648 type absolute radon meter. The measurement lasted continuously for several days and nights and a 'saddle shape' of radon content-time curve was observed. The day's average radon content was 8.5 Bq·m -3

  10. Instrumentation for a radon research house

    International Nuclear Information System (INIS)

    Nazaroff, W.W.; Revzan, K.L.; Robb, A.W.

    1981-07-01

    A highly automated monitoring and control system for studying radon and radon-daughter behavior in residences has been designed and built. The system has been installed in a research house, a test space contained in a two-story wood-framed building, which allows us to conduct controlled studies of (1) pollutant transport within and between rooms, (2) the dynamics of radon daughter behavior, and (3) techniques for controlling radon and radon daughters. The system's instrumentation is capable of measuring air-exchange rate, four-point radon concentration, individual radon daughter concentrations, indoor temerature and humidity, and outdoor weather parameters (temperature, humidity, modules, wind speed, and wind direction). It is also equipped with modules that control the injection of radon and tracer gas into the test space, the operation of the forced-air furnace, the mechanical ventilation system, and the mixing fans located in each room. A microcomputer controls the experiments and records the data on magnetic tape and on a printing terminal. The data on tape is transferred to a larger computer system for reduction and analysis. In this paper we describe the essential design and function of the instrumentation system, as a whole, singling out those components that measure ventilation rate, radon concentration, and radon daughter concentrations

  11. Measurement and apportionment of radon source terms for modeling indoor environments

    International Nuclear Information System (INIS)

    Harley, N.H.

    1992-01-01

    During the present 2 1/2 year contract period, we have made significant Progress in modeling the source apportionment of indoor 222 Rn and in 222 Rn decay product dosimetry. Two additional areas were worked on which we believe are useful for the DOE Radon research Program. One involved an analysis of the research house data, grouping the hourly house 222 Rn measurements into 2 day, 7 day and 90 day intervals to simulate the response of passive monitors. Another area requiring some attention resulted in a publication of 3 years of our indoor/outdoor measurements in a high-rise apartment. Little interest has been evinced in apartment measurements yet 20% of the US population lives in multiple-family dwellings, not in contact with the ground. These data together with a summary of all other published data on apartments showed that apartments have only about 50% greater 222 Rn concentration than the measured outdoor 222 Rn. Apartment dwellers generally represent a low risk group regarding 222 Rn exposure. The following sections describe the main projects in some detail

  12. Cost effectiveness of radon mitigation in Canada

    International Nuclear Information System (INIS)

    Letourneau, E.G.; Krewski, D.; Zielinski, J.M.; McGregor, R.G.

    1992-01-01

    This paper examines the cost effectiveness of comprehensive strategies for reducing exposure to radon gas in indoor air in Canadian homes. The analysis is conducted within the context of a general framework for risk management programme evaluation which includes well-known evaluation techniques such as cost effectiveness and cost-benefit analyses as special cases. Based on this analysis, it is clear that any comprehensive programme to reduce exposure to environmental radon will be extremely expensive, and may not be justifiable in terms of health impact, particularly when considered in relation to other public health programmes. Testing of homes at the point of sale and installing sub-slab suction equipment to reduce exposure to indoor radon where necessary appears to be a relatively cost-effective radon mitigation strategy. In general, radon mitigation was found to be most cost effective in cities with relatively high levels of radon. (author)

  13. Cost and effectiveness of radon barrier systems

    International Nuclear Information System (INIS)

    Baker, E.G.; Freeman, H.D.; Hartley, J.N.; Gee, G.W.

    1982-12-01

    Earthen, asphalt, and multilayer radon barrier systems can all provide reduction in the amount of radon gas released from uranium mill tailings. Pacific Northwest Laboratory field tested all three types of covers at Grand Junction, Colorado during the summer of 1981. All nine individual radon barrier systems tested currently meet the EPA standard for radon flux of 20 pCi m - 2 s - 1 . The cost of the asphalt and 3m earthen covers were about the same at the field test. Multilayer covers were significantly more costly. Cost estimates for three high priority western sites indicate 3m of earthen cover is the least costly radon barrier when earthen material is available at or near the disposal site. If earthen material must be imported more than 8 to 10 km asphalt and possibly multilayer radon barriers can be cost effective

  14. Radon in the Environment: Friend or Foe?

    International Nuclear Information System (INIS)

    Hussein, A.S.

    2009-01-01

    Radon 222 is a naturally occurring radioactive gas that is part of the Uranium decay series. Its Presence in the environment is associated mainly with trace amounts of uranium and its immediate parent, radium 226 , in rocks, soil and groundwater. About one-half of the effective doses from natural sources is estimated to be delivered by inhalation of the short lived radon progeny. Owing to this fact, radon is the most popular subject of studies on environmental radioactivity. The presence of high level of radon in indoor environment constitutes a major health hazard for man. The radon progeny is well established as causative agents of lung cancer and other types of caners. Radon unique properties as a naturally radioactive gas have led to its use as a geophysical tracer for locating buried faults and geological structures, in exploring for uranium, and for predicting earthquakes. Radon has been used as a tracer in the study of atmospheric transport process. There have been several other applications of radon in meteorology, water research and medicine. This paper summarizes the health effects and the potential benefits of radon and its progeny.

  15. Lung cancer attributable to indoor radon exposure in France using different risk models

    International Nuclear Information System (INIS)

    Catelinois, O.C.; Laurier, D.L.; Rogel, A.R.; Billon, S.B.; Tirmarche, M.T.; Hemon, Dh.; Verger, P.V.

    2006-01-01

    Full text of publication follows: Radon exposure is omnipresent for the general public, but at variable levels, because radon mainly comes from granitic and volcanic subs oils as well as from certain construction materials. Inhalation of radon is the main source of exposure to radioactivity in the general population of most countries. In 1988, the International Agency for Research on Cancer declared radon to be carcinogenic for humans (lung cancer): radon is classed in the group 1. The exposure of the overall general population to a carcinogenic component led scientists to assess the lung cancer risk associated to indoor radon. The aim of this work is to provide the first lung cancer risk assessment associated with indoor radon exposure in France, using all available epidemiological results and performing an uncertainty analysis. The number of lung cancer deaths potentially associated with radon in houses is estimated for the year 1999 according to several dose-response relationships which come from either cohorts of miners or joint analysis of residential case-controls studies. The variability of indoor radon exposure in France and uncertainties related to each of the dose-response relationships are considered. The assessment of lung cancer risk associated with domestic radon exposure considers 10 dose-response relationships resulting from miners cohorts and case-control studies in the general population. A critical review of available data on smoking habits has been performed and allowed to consider the interaction between radon and tobacco. The exposure data come from measurements campaigns carried out since the beginning of the 1980's by the Institute for Radiation protection and Nuclear Safety and the Health General Directory in France. The French lung cancer mortality data are provided by the INSERM. Estimates of the number of attributable cancers are carried out for the whole country, stratified by 8 large regions and b y 96 departments for the year 1999

  16. Modelling radiation exposure in homes from siporex blocks by using exhalation rates of radon

    Directory of Open Access Journals (Sweden)

    Nikolić Mladen D.

    2015-01-01

    Full Text Available Building materials are the second major source of indoor radon, after soil. The contribution of building materials to indoor radon amount depends upon the radium content and exhalation rates, which can be used as a primary index for radon levels in the dwellings. This paper presents the results of using the experimentally determined exhalation rates of siporex blocks and concrete plates, to assess the radiation exposure in dwellings built of siporex blocks. The annual doses in rooms have been estimated depending on the established modes of ventilation. Realistic scenario was created to predict an annual effective dose for an old person, a housewife, a student, and an employed tenant, who live in the same apartment, spending different periods of time in it. The results indicate the crucial importance of good ventilation of the living space.

  17. Geostatistical simulations for radon indoor with a nested model including the housing factor.

    Science.gov (United States)

    Cafaro, C; Giovani, C; Garavaglia, M

    2016-01-01

    The radon prone areas definition is matter of many researches in radioecology, since radon is considered a leading cause of lung tumours, therefore the authorities ask for support to develop an appropriate sanitary prevention strategy. In this paper, we use geostatistical tools to elaborate a definition accounting for some of the available information about the dwellings. Co-kriging is the proper interpolator used in geostatistics to refine the predictions by using external covariates. In advance, co-kriging is not guaranteed to improve significantly the results obtained by applying the common lognormal kriging. Here, instead, such multivariate approach leads to reduce the cross-validation residual variance to an extent which is deemed as satisfying. Furthermore, with the application of Monte Carlo simulations, the paradigm provides a more conservative radon prone areas definition than the one previously made by lognormal kriging. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Use of Radon for Evaluation of Atmospheric Transport Models: Sensitivity to Emissions

    Science.gov (United States)

    Gupta, Mohan L.; Douglass, Anne R.; Kawa, S. Randolph; Pawson, Steven

    2004-01-01

    This paper presents comparative analyses of atmospheric radon (Rn) distributions simulated using different emission scenarios and the observations. Results indicate that the model generally reproduces observed distributions of Rn but there are some biases in the model related to differences in large-scale and convective transport. Simulations presented here use an off-line three-dimensional chemical transport model driven by assimilated winds and two scenarios of Rn fluxes (atom/cm s) from ice-free land surfaces: (A) globally uniform flux of 1.0, and (B) uniform flux of 1.0 between 60 deg. S and 30 deg. N followed by a sharp linear decrease to 0.2 at 70 deg. N. We considered an additional scenario (C) where Rn emissions for case A were uniformly reduced by 28%. Results show that case A overpredicts observed Rn distributions in both hemispheres. Simulated northern hemispheric (NH) Rn distributions from cases B and C compare better with the observations, but are not discernible from each other. In the southern hemisphere, surface Rn distributions from case C compare better with the observations. We performed a synoptic scale source-receptor analysis for surface Rn to locate regions with ratios B/A and B/C less than 0.5. Considering an uncertainty in regional Rn emissions of a factor of two, our analysis indicates that additional measurements of surface Rn particularly during April-October and north of 50 deg. N over the Pacific as well as Atlantic regions would make it possible to determine if the proposed latitude gradient in Rn emissions is superior to a uniform flux scenario.

  19. Comparison of two numerical modelling approaches to a field experiment of unsaturated radon transport in a covered uranium mill tailings soil (Lavaugrasse, France)

    Energy Technology Data Exchange (ETDEWEB)

    Saadi, Zakaria; Guillevic, Jerome [Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-DGE/SEDRAN/BRN, 31 avenue de la Division Leclerc, B.P. 17, 92262, Fontenay-aux-Roses, Cedex (France)

    2014-07-01

    Uncertainties on the mathematical modelling of radon transport in an unsaturated covered uranium mill tailings (UMT) soil at field scale can have a great impact on the estimation of the average measured radon flux to the atmosphere at the landfill cover, which must be less than the threshold value 0.74 Bq.m{sup -2}.s{sup -1}recommended by the federal standard (EPA 40 CFR 192). These uncertainties are usually attributed to the numerical errors from the numerical schemes dealing with soil layering and to inadequate representations of the modelling of physical processes at the soil/plant/atmosphere interface and of the soil hydraulic and transport properties, as well as their parameterization. In this work, we compare one-dimensional simulation results from two numerical models of two-phase (water-air) porous media flow and radon transport to the data of radon activity exhalation flux and depth-volumetric concentration measured during a field campaign from June to November of 1999 in a two-layered soil of 1.3 m thickness (i.e., cover material/UMT: 0.5/0.8 m) of an experimental pond located at the Lavaugrasse UMT-landfill site (France). The first numerical modelling approach is a coupled finite volume compositional (i.e., water, radon, air) transport model (TOUGH2/EOS7Rn code, Saadi et al., 2013), while the second one is a decoupled finite difference one-component (i.e., radon) transport model (TRACI code, Ferry et al., 2001). Transient simulations during six month of hourly rainfall and atmospheric pressure variations showed that calculations from the one-component transport model usually overestimate both measured radon exhalation flux and depth-concentration. However, considering the effective unsaturated pore air-component diffusivity to be different from that of the radon-component in the compositional transport model allowed to significantly enhancing the modelling of these radon experimental data. The time-averaged radon flux calculated by EOS7Rn (3.42 Bq

  20. Design and investigation of a continuous radon monitoring network for earthquake precursory process in Great Tehran

    International Nuclear Information System (INIS)

    Negarestani, A.; Namvaran, M.; Hashemi, S.M.; Shahpasandzadeh, M.; Fatemi, S.J.; Alavi, S.A.; Mokhtari, M.

    2014-01-01

    Earthquakes usually occur after some preliminary anomalies in the physical and chemical characteristics of environment and earth interior. Construction of the models which can explain these anomalies, prompt scientists to monitor geophysical and geochemical characteristics in the seismic areas for earthquake prediction. A review of studies has been done so far, denoted that radon gas shows more sensitivity than other geo-gas as a precursor. Based on previous researches, radon is a short-term precursor of earthquake from time point of view. There are equal experimental equations about the relation between earthquake magnitude and its effective distance on radon concentration variations. In this work, an algorithm based on Dobrovolsky equation (D=10 0.43M ) with defining the Expectation and Investigation circles for great Tehran has been used. Radon concentration was measured with RAD7 detector in the more than 40 springs. Concentration of radon in spring, spring discharge, water temperature and the closeness of spring location to active faults, have been considered as the significant factors to select the best spring for a radon continuous monitoring site implementation. According to these factors, thirteen springs have been selected as follow: Bayjan, Mahallat-Hotel, Avaj, Aala, Larijan, Delir, Lavij, Ramsar, Semnan, Lavieh, Legahi, Kooteh-Koomeh and Sarein. (author)

  1. Natural gamma-ray spectrometry as a tool for radiation dose and radon hazard modelling

    International Nuclear Information System (INIS)

    Verdoya, M.; Chiozzi, P.; De Felice, P.; Pasquale, V.; Bochiolo, M.; Genovesi, I.

    2009-01-01

    We reviewed the calibration procedures of gamma-ray spectrometry with particular emphasis to factors that affect accuracy, detection limits and background radiation in field measurements for dosimetric and radon potential mapping. Gamma-ray spectra were acquired in western Liguria (Italy). The energy windows investigated are centred on the photopeaks of 214 Bi (1.76 MeV), 208 Tl (2.62 MeV) and 40 K (1.46 MeV). The inferred absorbed dose rate and the radon flux are estimated to be lower than 60 nGy h -1 and 22 Bq m -2 h -1 , respectively.

  2. Radon: implications for the health professional

    International Nuclear Information System (INIS)

    Romano, C.A.

    1990-01-01

    Radon is a colorless, odorless gas formed by radioactive decay of radium and uranium, which are naturally present in the earth's crust. When concentrated indoors, this invisible gas becomes a potential health hazard. The Environmental Protection Agency estimates that up to 20,000 lung cancer deaths annually can be attributed to prolonged radon exposure. Radon is an important health issue that should be understood by all health care professionals. This paper discusses some of the important issues regarding radon, such as the incidences of lung cancer believed to be attributable to radon, the high-risk areas in the United States, federal safety guidelines, and public apathy. These issues and their impact on the health care required by professionals, especially nurse practitioners, are discussed

  3. Mapping geogenic radon potential by regression kriging

    Energy Technology Data Exchange (ETDEWEB)

    Pásztor, László [Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Department of Environmental Informatics, Herman Ottó út 15, 1022 Budapest (Hungary); Szabó, Katalin Zsuzsanna, E-mail: sz_k_zs@yahoo.de [Department of Chemistry, Institute of Environmental Science, Szent István University, Páter Károly u. 1, Gödöllő 2100 (Hungary); Szatmári, Gábor; Laborczi, Annamária [Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Department of Environmental Informatics, Herman Ottó út 15, 1022 Budapest (Hungary); Horváth, Ákos [Department of Atomic Physics, Eötvös University, Pázmány Péter sétány 1/A, 1117 Budapest (Hungary)

    2016-02-15

    Radon ({sup 222}Rn) gas is produced in the radioactive decay chain of uranium ({sup 238}U) which is an element that is naturally present in soils. Radon is transported mainly by diffusion and convection mechanisms through the soil depending mainly on the physical and meteorological parameters of the soil and can enter and accumulate in buildings. Health risks originating from indoor radon concentration can be attributed to natural factors and is characterized by geogenic radon potential (GRP). Identification of areas with high health risks require spatial modeling, that is, mapping of radon risk. In addition to geology and meteorology, physical soil properties play a significant role in the determination of GRP. In order to compile a reliable GRP map for a model area in Central-Hungary, spatial auxiliary information representing GRP forming environmental factors were taken into account to support the spatial inference of the locally measured GRP values. Since the number of measured sites was limited, efficient spatial prediction methodologies were searched for to construct a reliable map for a larger area. Regression kriging (RK) was applied for the interpolation using spatially exhaustive auxiliary data on soil, geology, topography, land use and climate. RK divides the spatial inference into two parts. Firstly, the deterministic component of the target variable is determined by a regression model. The residuals of the multiple linear regression analysis represent the spatially varying but dependent stochastic component, which are interpolated by kriging. The final map is the sum of the two component predictions. Overall accuracy of the map was tested by Leave-One-Out Cross-Validation. Furthermore the spatial reliability of the resultant map is also estimated by the calculation of the 90% prediction interval of the local prediction values. The applicability of the applied method as well as that of the map is discussed briefly. - Highlights: • A new method

  4. Mapping geogenic radon potential by regression kriging

    International Nuclear Information System (INIS)

    Pásztor, László; Szabó, Katalin Zsuzsanna; Szatmári, Gábor; Laborczi, Annamária; Horváth, Ákos

    2016-01-01

    Radon ( 222 Rn) gas is produced in the radioactive decay chain of uranium ( 238 U) which is an element that is naturally present in soils. Radon is transported mainly by diffusion and convection mechanisms through the soil depending mainly on the physical and meteorological parameters of the soil and can enter and accumulate in buildings. Health risks originating from indoor radon concentration can be attributed to natural factors and is characterized by geogenic radon potential (GRP). Identification of areas with high health risks require spatial modeling, that is, mapping of radon risk. In addition to geology and meteorology, physical soil properties play a significant role in the determination of GRP. In order to compile a reliable GRP map for a model area in Central-Hungary, spatial auxiliary information representing GRP forming environmental factors were taken into account to support the spatial inference of the locally measured GRP values. Since the number of measured sites was limited, efficient spatial prediction methodologies were searched for to construct a reliable map for a larger area. Regression kriging (RK) was applied for the interpolation using spatially exhaustive auxiliary data on soil, geology, topography, land use and climate. RK divides the spatial inference into two parts. Firstly, the deterministic component of the target variable is determined by a regression model. The residuals of the multiple linear regression analysis represent the spatially varying but dependent stochastic component, which are interpolated by kriging. The final map is the sum of the two component predictions. Overall accuracy of the map was tested by Leave-One-Out Cross-Validation. Furthermore the spatial reliability of the resultant map is also estimated by the calculation of the 90% prediction interval of the local prediction values. The applicability of the applied method as well as that of the map is discussed briefly. - Highlights: • A new method, regression

  5. The BERR gas market model

    International Nuclear Information System (INIS)

    2007-10-01

    Security of supply is one of the key objectives in the UK's department of Business Enterprise and Regulatory Reform (BERR) gas market model. BERR found that a useful way to measure energy security was to estimate future 'expected energy unserved'. This comprises a combination of possible levels of shortfall between supply and demand and other probabilities to give a probability-weighted amount of unserved demand. BERR has also studied the conditions (inputs) that are likely to result in lower expected energy unserved, i.e. it has identified the drivers of security of supply and has developed a framework for categorising these drivers

  6. Study of different factors which can explain the radon exhalation potential of soils

    International Nuclear Information System (INIS)

    Demongeot, St.

    1997-01-01

    Radon is a natural radioactive gas belonging to the Uranium-238 chain, which is present in the earth crust and produced by the disintegration of radium-226. It is considered as the major source of radiological exposure of man to natural radiation because it can accumulate in indoor atmosphere. So, this health risk must be take into account.The aim of this study is to find some tools in order to identify high radon level area. The first part of this study has consisted in measurement of radon emission from different not sufficient for the estimation of the radon exhalation potential in a given area. In the second part of this work, we have studied the variations of in situ radon concentration as a function of different geological and pedologic parameters of the site. With the results obtained, we have determined the data which have to be considered, and the methodology to be applied for the determination of the radon exhalation of a given area. Furthermore, by the mean of numerical simulations (TRACH Model), it was possible to know the scale of radon flux variation in a given point versus the hydric state of the ground and thus the permeability: these parameters are not easy to measure because of their variabilities with time. The methodology ESPERAS (EStimation du Potential d'Exhalation en Radon des Sols) developed during this work was applied first, at a local scale and then to greater area. The values estimated by this way are in a good agreement with the results of measurements. So, we can determine the areas which are affected by high radon levels. (author)

  7. The Radon Book. Preventive measures in new buildings

    International Nuclear Information System (INIS)

    Clavensjoe, Bertil; Aakerblom, Gustav

    2004-01-01

    This book describes in text and picture how one can prevent that the radon concentrations in new buildings become to high. The book's centre of gravity lies on how to build in order to prevent that radon gas from the ground enters the building. The book contains extensive information about ground radon and how to examine the ground before constructing a new building. Release of radon from ground water and construction material is treated, as well as technology for measurement of radon and gamma radiation. The book presents current threshold values/recommended values for radon and the authorities' regulations and recommendations. The book is directed to persons who professionally need knowledge about radon and how to prevent that radon is accumulated in new buildings

  8. A study of radon variation in dwelling during 1988

    International Nuclear Information System (INIS)

    Shaikh, A.N.; Ramachandran, T.V.; Muraleedharan, T.S.; Subbaramu, M.C.

    1989-01-01

    Natural radioactivity due to radon and its progeny levels indoors contributes significantly to the total radiation to man. The main source of radon and its progeny in a dwelling is the emanation of radon gas from soil. The temperature and ventilation vary in a dwelling during the year. These parameters influence the indoor radon levels. The seasonal variation of radon was studied in a dwelling as well as in the outside air. The filter paper method and alpha counting, and the solid state track detector technique and track counting were used to study the radon levels. The geometric mean of radon daughters concentrations were 0.5 mWL and 0.8 mWL measured by filter-paper method and SSNTD method respectively. The geometric mean of radon concentrations were 6.2 Bqm -3 and 10.0 Bqm -3 by filter-paper method and SSNTD method respectively. (author). 3 figs., 3 tabs., 13 refs

  9. Radon in schools. Report for May 1988-September 1989

    International Nuclear Information System (INIS)

    Leovic, K.W.

    1989-01-01

    The paper discusses radon entry into schools, radon mitigation approaches for schools, and school characteristics (e.g., HVAC system design and operation) that influence radon entry and mitigation system design. It also discusses mitigation systems installed by the U.S. EPA in four schools. The primary source of radon entry into a school with significantly elevated radon levels is normally soil gas that is drawn in by pressure differentials between the soil surrounding the substructure and the building interior. If the building interior is at a lower pressure than the soil surrounding the substructure and radon is present in the soil, the radon can be pulled in through cracks and other openings that are in contact with the soil. The amount of radon in a given classroom depends on the level of radon in the underlying material, the ease with which the radon moves as a component of the soil gas through the soil, the magnitude and direction of the pressure differentials, the number and size of the radon entry routes, and dilution and mixing of the room air. HVAC systems in schools vary considerably and tend to have greater impact on pressure differentials--and consequently radon levels--than do heating and air-conditioning (HAC) systems in houses

  10. MEASUREMENTS ON, AND MODELING OF DIFFUSIVE AND ADVECTIVE RADON TRANSPORT IN SOIL

    NARCIS (Netherlands)

    VANDERGRAAF, ER; WITTEMAN, GAA; VANDERSPOEL, WH; ANDERSEN, CE; DEMEIJER, RJ

    1994-01-01

    Results are presented of measurements on radon transport in soil under controlled conditions with a laboratory facility consisting of a stainless steel vessel (height and diameter 2 m) filled with a uniform column of sand. At several depths under the sand surface, probes are radially inserted into

  11. Result of the intercomparison exercise on radon measuring instruments and radon detectors 'bev- radon ring 2005'

    International Nuclear Information System (INIS)

    Baumgartner, A.; Maringer, F.J.; Michai, P.; Kreuziger, M.

    2006-01-01

    In spring 2005 the Federal Office of Metrology and Surveying (B.E.V.) invited all in Austria working radon measuring institutes to an intercomparison exercise at the radon calibration laboratory in the Arsenal. The aim of this intercomparison was on the one hand an objective inquiry and documentation of the current metrological potential on the section of radon measurement in Austria - both quantitative and qualitative- and on the other hand an initiative for the participating laboratories to optimize and improve their applied calibration-, measurement and analyse technique. Ten contacted Austrian radon laboratories were prepared to participate on the radon intercomparison exercise. The intercomparison exercise was carried out from 14. till 29. June at the radon calibration laboratory in the Arsenal of the B.E.V.. As radon emanation source a five stepped arranged, at the Arsenal built radon source was used. The source ( A.D.O.T.T.O. 1 is filled with a certified Ra- 226-standard solution of the Czech Metrological Institute (C.M.I.), Prag. A simple statistic based model was used for the evaluation and assessment of the results from the participants, which consider the statistic nature of the radioactive decay combined uncertainty. Altogether 183 measuring instruments participated the intercomparison exercise. Two reference measuring instruments, 22 active and 159 passive measuring instruments. The active measuring instruments formed 6 types of instruments and as passive radon detectors were 7 different types used from the participants. The positioning of the radon measuring instruments and detectors in the radon calibration laboratory was executed in regard to statistic points of view. From the active measuring instruments 17 could qualify and from the passive methods six from eight participants were in compliance to the given criteria. Radon measurements, which could have financial and economics relating implications (e.g. architectural redevelopment or

  12. Indoor air radon

    International Nuclear Information System (INIS)

    Cothern, C.R.

    1990-01-01

    This review concerns primarily the health effects that result from indoor air exposure to radon gas and its progeny. Radon enters homes mainly from the soil through cracks in the foundation and other holes to the geologic deposits beneath these structures. Once inside the home the gas decays (half-life 3.8 d) and the ionized atoms adsorb to dust particles and are inhaled. These particles lodge in the lung and can cause lung cancer. The introduction to this review gives some background properties of radon and its progeny that are important to understanding this public health problem as well as a discussion of the units used to describe its concentrations. The data describing the health effects of inhaled radon and its progeny come both from epidemiological and animal studies. The estimates of risk from these two data bases are consistent within a factor of two. The epidemiological studies are primarily for hard rock miners, although some data exist for environmental exposures. The most complete studies are those of the US, Canadian, and Czechoslovakian uranium miners. Although all studies have some deficiencies, those of major importance include uranium miners in Saskatchewan, Canada, Swedish iron miners, and Newfoundland fluorspar miners. These six studies provide varying degrees of detail in the form of dose-response curves. Other epidemiological studies that do not provide quantitative dose-response information, but are useful in describing the health effects, include coal, iron ore and tin miners in the UK, iron ore miners in the Grangesburg and Kiruna, Sweden, metal miners in the US, Navajo uranium miners in the US, Norwegian niobian and magnitite miners, South African gold and uranium miners, French uranium miners, zinc-lead miners in Sweden and a variety of small studies of environmental exposure. An analysis of the epidemiological studies reveals a variety of interpretation problem areas.172 references

  13. Behaviors of radon in indoor environment

    International Nuclear Information System (INIS)

    Mochizuki, Sadamu; Shimo, Michikuni.

    1987-01-01

    The source of radon ( 222 Rn) in the atmosphere is radioactive nuclide, uranium ( 238 U), which exists fairly common throughout the earth's crust. Radium ( 226 Ra) descended from uranium produce radon ( 222 Rn) of noble gas by decay. After formation in the ground, radon diffuses into the atmosphere. Without exception radon decay products are heavy metals which soon become attached to natural aerosols. Therefore, radon and its daughters (decay products) appear also in indoor environment, and generally, their concentration levels become higher than that of outdoor air due to build-up effects in the closed indoor environments. With the progress of the study on the influence of radon and its daughers on human health, it has become clear that they act effectively as an exciting cause of lung cancer. So, the study on the risk evaluation of them in room air has become to be very important. Concequently, the behaviors of radon and its daughters in indoor environment, first of all, should be studied in detail for the accurate estimation of the risk caused by them. In this special edition, fundamental characteristics of radon and its daughters, some measuring methods, theoretical considerations and some observational evidences obtained from various circumstances of indoor environment are described inorder to grasp and understand the behaviors of radon and its daughters in the indoor environment. (author)

  14. Off gas condenser performance modelling

    International Nuclear Information System (INIS)

    Cains, P.W.; Hills, K.M.; Waring, S.; Pratchett, A.G.

    1989-12-01

    A suite of three programmes has been developed to model the ruthenium decontamination performance of a vitrification plant off-gas condenser. The stages of the model are: condensation of water vapour, NO x absorption in the condensate, RuO 4 absorption in the condensate. Juxtaposition of these stages gives a package that may be run on an IBM-compatible desktop PC. Experimental work indicates that the criterion [HNO 2 ] > 10 [RuO 4 ] used to determine RuO 4 destruction in solution is probably realistic under condenser conditions. Vapour pressures of RuO 4 over aqueous solutions at 70 o -90 o C are slightly lower than the values given by extrapolating the ln K p vs. T -1 relation derived from lower temperature data. (author)

  15. Radon risk mapping of the Czech Republic on a scale 1:50000

    International Nuclear Information System (INIS)

    Barnet, I.; Miksova, J.; Tomas, R.; Karenova, J.

    2000-01-01

    A new type of radon risk maps on a scale 1:50000 was published in the Czech Republic. Maps are based on the vectorized contours of' geological units and rock types and field soil gas radon measurements from the radon database. Radon risk is expressed in four categories. More detailed topography enables to predict the radon risk from bedrock in the intravilans of villages and towns. (author)

  16. Managing Radon in Schools

    Science.gov (United States)

    EPA recommends testing all schools for radon. As part of an effective IAQ management program, schools can take simple steps to test for radon and reduce risks to occupants if high radon levels are found.

  17. A perspective on risks from radon

    International Nuclear Information System (INIS)

    Higson, D. J.

    2010-10-01

    In its Statement on Radon (November 2009), the International Commission on Radiological Protection (ICRP) has reduced the upper reference level for radon gas in dwellings to 300 Bq m -3 . The recommended level for workplaces is 1000 Bq m -3 . A risk coefficient of 8 x 10 -10 per Bq h m -3 is recommended without reference to smoking habits. On the basis of these figures: 1) The estimated risk of fatal cancer from exposure to radon at home and at work could be greater than the observed risk of accidental death from travelling by car, which would be surprising if true. 2) The estimated risk of lung cancer from radon could be greater than the observed risk of lung cancer from all causes, which is actually known to be dominated by smoking. The author is not aware of any direct evidence of risks from inhaling radon in Australian dwellings, 99% of which have radon levels below 50 Bq m -3 . Evidence available from other countries shows that: 1) The effects of radon in the incidences of lung cancer are uncertain at levels less then about 50-100 Bq m -3 . 2) The estimation of risks at levels below 200 Bq m -3 depends on extrapolation from risks observed at higher levels. 3) Risks to non-smokers from radon are 25 times less than risks to smokers. Its concluded that the ICRP Statement on Radon and radon policies in the US and UK have the potential to cause unwarranted concern. Some people may be made to feel they need to spend money modifying their homes and workplaces to protect occupants from exposure to radon when there is no compelling reason to show that this is necessary. The vast majority of non-smokers do not need to be protected from radon. (Author)

  18. A perspective on risks from radon

    International Nuclear Information System (INIS)

    Higson, D.J.

    2011-01-01

    In its Statement on Radon (November 2009), the ICRP has reduced the upper reference level for radon gas in dwellings to 300 Bq m -3 . The recommended level for workplaces is 1000 Bq m -3 . A risk coefficient of 8x10 -10 per Bq h m is recommended without reference to smoking habits. On the basis of these figures,the estimated risk of fatal cancer from exposure to radon at home and at work could be greater than the observed risk of accidental death from travelling by car, which would be surprising if true. Also the estimated risk of lung cancer from radon could be greater than the observed risk of lung cancer from all causes, which is actually known to be dominated by smoking. The author is not aware of any direct evidence of risks from inhaling radon in Australian dwellings, 99% of which have radon levels below 50 Bq m -3 . Evidence available from other countries shows that: effects on the incidences of lung cancer are uncertain at radon levels below 100 Bq m -3 ; the estimation of risks at levels below 200 Bq m -3 depends on extrapolation from risks observed at higher levels, and risks to non-smokers from radon are 25 times less than risks to smokers. It is concluded that the ICRP Statement on Radon and radon policies in the US and UK have the potential to cause unwarranted concern. Some people may be made to feel they need to spend money modifying their homes and workplaces to protect occupants from exposure to radon when there is no compelling reason to show that this is necessary. The vast majority of non-smokers do not need to be protected from radon.

  19. A perspective on risks from radon

    Energy Technology Data Exchange (ETDEWEB)

    Higson, D. J., E-mail: higsond@bigpond.net.a [Australasian Radiation Protection Society, PO Box 7108, Upper Ferntree Gully, Victoria 3156 (Australia)

    2010-10-15

    In its Statement on Radon (November 2009), the International Commission on Radiological Protection (ICRP) has reduced the upper reference level for radon gas in dwellings to 300 Bq m{sup -3}. The recommended level for workplaces is 1000 Bq m{sup -3}. A risk coefficient of 8 x 10{sup -10} per Bq h m{sup -3} is recommended without reference to smoking habits. On the basis of these figures: 1) The estimated risk of fatal cancer from exposure to radon at home and at work could be greater than the observed risk of accidental death from travelling by car, which would be surprising if true. 2) The estimated risk of lung cancer from radon could be greater than the observed risk of lung cancer from all causes, which is actually known to be dominated by smoking. The author is not aware of any direct evidence of risks from inhaling radon in Australian dwellings, 99% of which have radon levels below 50 Bq m{sup -3}. Evidence available from other countries shows that: 1) The effects of radon in the incidences of lung cancer are uncertain at levels less then about 50-100 Bq m{sup -3}. 2) The estimation of risks at levels below 200 Bq m{sup -3} depends on extrapolation from risks observed at higher levels. 3) Risks to non-smokers from radon are 25 times less than risks to smokers. Its concluded that the ICRP Statement on Radon and radon policies in the US and UK have the potential to cause unwarranted concern. Some people may be made to feel they need to spend money modifying their homes and workplaces to protect occupants from exposure to radon when there is no compelling reason to show that this is necessary. The vast majority of non-smokers do not need to be protected from radon. (Author)

  20. Radon in homes of the Portland, Oregon Area: Radon data from local radon testing companies collected by CRM (Continuous Radon Measurement) machines

    Science.gov (United States)

    Whitney, H.; Lindsey, K.; Linde, T.; Burns, S. F.

    2013-12-01

    Students from the Department of Geology at Portland State University paired up with the Oregon Health Authority to better understand radon gas values in homes of the Portland metropolitan area. This study focuses on radon values collected by continuous radon measurement (CRM) machines, taken by local radon testing companies. The local companies participating in this study include Alpha Environmental Services, Inc., Cascade Radon, Environmental Works, The House Detectives, LLC, and Soil Solutions Environmental Services, Inc. In total, 2491 radon readings spanning across 77 zip codes were collected from local companies in the Portland metropolitan area. The maximum value, average value, percentage of homes greater than 4 pCi/L and total rank sum was calculated and used to determine the overall radon potential for each zip code (Burns et al., 1998). A list and four maps were produced showing the results from each category. Out of the total records, 24 zip codes resulted in high radon potential and the average reading for the entire Portland Metropolitan area was 3.7 pCi/L. High potential zip codes are thought to be a result of sand and gravel (Missoula Flood deposits) and faults present in the subsurface. The CRM data was compared with both long-term and short-term data provided by the Oregon Health Authority to validate radon potentials in each zip code. If a home is located in a zip code with high or moderate radon potential across two types of data sets, it is recommended that those homes be tested for radon gas.

  1. Radon Protection in the Technical Building Code

    International Nuclear Information System (INIS)

    Frutos, B.; Garcia, J. P.; Martin, J. L.; Olaya, M.; Serrano, J I.; Suarez, E.; Fernandez, J. A.; Rodrigo, F.

    2003-01-01

    Building construction in areas with high radon gas contamination in land requires the incorporation of certain measures in order to prevent the accumulation of this gas on the inside of buildings. These measures should be considered primarily in the design and construction phases and should take the area of the country into consideration where the construction will take place depending on the potential risk of radon entrance. Within the Technical Building Code, radon protection has been considered through general classification of the country and specific areas where building construction is to take place, in different risk categories and in the introduction of building techniques appropriate for each area. (Author) 17 refs

  2. Indoor radon measurements and radon prognosis for the province of Kymi, southeastern Finland

    International Nuclear Information System (INIS)

    Pennanen, M.; Maekelaeinen, I.; Voutilainen, A.

    1996-12-01

    The purpose of the regional radon prognosis is to classify areas with different levels of radon risk. The radon prognosis gives the percentages of future homes expected to have indoor radon concentrations exceeding the levels of 200 and 400 Bq/m 3 . It is assumed that no protection against the entry of radon is used in construction. In this study about 5900 indoor radon measurements made in single family houses, semi-detached houses and row houses were used. Data on the location, geology and construction of buildings were determined from maps and questionnaires. An empirical statistical model, the adjusted indoor radon measurements and geological data were used to assess the radon risk from soil and bedrock in different areas. The building sites of the province of Kymi were divided into thirteen sub-areas. The radon prognosis are calculated for the most radon-prone foundation types including 1) houses with a slab-on-grade and 2) houses with a basement or hillside houses with open stairwells between basement and first floor. The radon levels are generally greater in the western part of the area. The radon risk is highest in gravel-dominated esker areas in southwestern, western (in Pyhtaa, Kotka, Anjalankoski, litti, Valkeala) and central (Taipalsaari) parts of the area. The radon risk is also high in some bedrock and till areas, also in southwestern and western parts of the area. In these areas the level of 200 Bq/m 3 will be exceeded in 80 % of new houses. About half of the future houses in these areas will have indoor radon concentrations exceeding 400 Bq/m 3 . The radon risk is lowest in the eastern part of the province of Kymi in every soil type. In this area the level of 200 Bq/m 3 will be exceeded in 30 % of new houses. Below 10 % will exceed 400 Bq/m 3 . (orig.) (14 refs.)

  3. Radon in soil variations for Vrancea seismic area

    International Nuclear Information System (INIS)

    Zoran, M.

    2002-01-01

    Earthquakes occur as a result of a build up of pressure between colliding sections of the Earth's crust. These sections, known as continental plates, meet at 'fault lines'. According to classical earthquake theory, small earthquakes should continue to grow into large earthquakes until they spread all along the fault line. Vrancea region is fitted to such a model. The mechanical processes of earthquake preparation are always accompanied by deformations, afterwards complex short- or long term precursory phenomena can appear. Macro-fracturing processes are preceded by micro-fracturing phenomena with a resulting radon and other gas precursors (He, CH 4 , NO) anomalies in soil-gas and groundwater. Studies of geochemical and hydrological anomalies preceding significant earthquakes have been reported from China, Japan, Uzbekistan, Mexico, Italy, India and Germany. However, studies of these pre-seismic phenomena have been controversial for several reasons. Temporal variations of radon in soil or water, can give evidence that the emanation of this gas can be correlated with tectonic disturbances. I used nuclear track detectors LR-115 and CN-85 for radon concentration monitoring in soil at 50 cm depth exposed for a period of 30 days in Vrancioaia test area. Time series radon data in soil-gas during of two years long observation period have established that more than 50% of radon concentration increases were correlated with microseismic events of 2-4 magnitude on Richter scale. A clear positive correlation for radon concentration prior one month of seismic event was associated with a registered event of magnitude 5. In order to differentiate the changes due to tectonic disturbances and that of meteorological parameters, were measured barometric pressure, precipitation and temperature. Negative correlation between radon concentration in soil and meteorological parameters was found. To predict a future earthquake, all precursory phenomena must be investigated. The

  4. Molecular and cytogenetic characterization of radon-induced lung tumors in the rat

    International Nuclear Information System (INIS)

    Dano, Laurent

    2000-01-01

    Radon is a natural radioactive gas. This radioelement, which is an α-particle emitter, is omnipresent in the environment. Inhalation of atmospheric radon is the major exposure route in man of natural radioactivity which results in respiratory tract contamination. An increased lung cancer risk associated with radon inhalation has been shown both in humans and animals by epidemiological and experimental studies, respectively. In rats, characterization of dose-effect relationships has led to the construction of statistical models that may help theoretically in the prediction of human health involvements of both occupational and domestic chronic exposure to radon. However, little is known about the cellular and molecular mechanisms of radon-induced lung carcinogenesis. In the laboratory, a model of lung cancers induced in rats after radon inhalation is available. This model represents a good tool to identify and characterize the genetic events contributing to the development of radon-induced lung tumors. Carrying out a global approach based on the combined use of classical and molecular cytogenetic methods, the analysis of 17 neoplasms allowed the identification of chromosomal regions frequently altered in these tumors. Numerous similarities have been found between our results and the cytogenetic data for human lung cancers, suggesting common underlying genetic molecular mechanisms for lung cancer development in both species. Moreover, our study has allowed to point to tumor suppressor genes and proto-oncogenes potentially involved in radon-induced lung carcinogenesis. Thus, our results may aid further molecular studies aimed either at confirming the role of these candidate genes or at demonstrating the involvement of yet to be identified genes. (author) [fr

  5. Measurements of radon and chemical elements: Popocatepetl volcano; Mediciones de radon y elementos quimicos: Volcan Popocatepetl

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Segovia, N.; Lopez, B.; Reyes, A.V. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Armienta, M.A.; Valdes, C.; Mena, M. [IGFUNAM, Ciudad Universitaria, 04510 Mexico D.F. (Mexico); Seidel, J.L.; Monnin, M. [UMR 5569 CNRS Hydrosciences, Montpellier (France)

    2002-07-01

    The Popocatepetl volcano is a higher risk volcano located at 60 Km from Mexico City. Radon measurements on soil in two fixed seasons located in the north slope of volcano were carried out. Moreover the radon content, major chemical elements and tracks in water samples of three springs was studied. The radon of soil was determined with solid detectors of nuclear tracks (DSTN). The radon in subterranean water was evaluated through the liquid scintillation method and it was corroborated with an Alpha Guard equipment. The major chemical elements were determined with conventional chemical methods and the track elements were measured using an Icp-Ms equipment. The radon on soil levels were lower, indicating a moderate diffusion of the gas across the slope of the volcano. The radon in subterranean water shown few changes in relation with the active scene of the volcano. The major chemical elements and tracks showed a stable behavior during the sampling period. (Author)

  6. Estimated risks of radon-induced lung cancer by two-mutation model for different exposures in mines and in homes

    International Nuclear Information System (INIS)

    Boehm, K.; Nikodemova, D.; Salat, D.; Drabova, D.

    2005-01-01

    In this work, the two-mutation model has been applied and compared with BEIR VI models for a prediction of the radon risk in various environments. The obtained results can be summarised into several points. The values of risk from the radon exposure predicted by the two-mutation model are comparable with the results obtained by BEIR VI for the short-time as well as for the long-time exposures. In the range of low exposures is this agreement of the results closer to the risk values assessed by the exposure-age-concentration model. In the range of higher exposures the results are closer to the values based on the age- duration model. The two-mutation model predicts the increase of dRR/dC with the increase of the radon concentration in the range of low concentrations. According to our results the inverse effect occurs only when the radon concentrations reach the value of 1500 Bq/m 3 . The two-mutation model can be taken as an universal model for the risk calculation in different environments, and for various smoking status. This model makes possible to analyse the influence of the fractionalisation of the exposure on the resulting RR. (authors)

  7. AlphaGUARD, the new reference for continuous radon monitoring in air, soil, gas, water and material; AlphaGUARD, die neue Referenz fuer die kontinuierliche Messung der Radonkonzentration in Luft, Boden, Wasser und Baumaterial

    Energy Technology Data Exchange (ETDEWEB)

    Roessler, F.; Buerkin, W. [Saphymo GmbH, Frankfurt am Main (Germany); Villert, J. [Bertin Technologies, Montigny (France)

    2016-07-01

    The company Saphymo GmbH has more than 25 years of experience in the field of radon measurement. More than 20 years ago Saphymo developed the professional and robust radon monitor AlphaGUARD, quickly recognized as a standard for reliable and continuous measurements of the radon concentration. Today AlphaGUARD is internationally established as the reference in radon measurement. Following up on this success story the new generation of AlphaGUARD can now be presented. Based on the excellent measurement characteristics of its predecessor the new AlphaGUARD combines the well-proven principle of the pulse ionisation chamber with new and additional features. The robust housing is oriented on the well-proven design of the predecessor and includes now an integrated flow controlled and powerful pump. The instrument can be operated in flow as well as in diffusion mode (without pump). Via the new large display and the intuitive menu navigation all measurement data can be retrieved. The presentation of time series in charts is possible as well as the parametrisation of the instrument. A wide range of accessories, developed in cooperation with various radon experts of universities and laboratories, enables the user a varied and flexible application of the AlphaGUARD: Measurement of the radon concentration in air (radon, thoron, radon progenies), in water (sampling and time resolved measurements) and in soil (soil gas measurements, exhalation measurements), emanation measurements from material, multi spot measurement, online measurement with remote data transmission via Ethernet/DSL, Bluetooth, Wi-Fi, GPRS/3G or satellite. Due to its high sensitivity and its fast and linear response over a large measuring range the AlphaGUARD is excellently suited for calibration laboratories. Furthermore the AlphaGUARD enables ideal prerequisites for field applications: robust housing for operations under harsh conditions, long battery life for the measurement at any location, low

  8. A cost-effect analysis of an intervention against radon in homes

    Directory of Open Access Journals (Sweden)

    Hein Stigum

    2009-10-01

    Full Text Available Background  Key words  : Radon exposure, lung cancer, cost-effect analysis, attributable risk, models-mathematical: Radon is a radioactive gas that may leak into buildings from the ground. Radon exposure is a risk factor for lung cancer. An intervention against radon exposure in homes may consist of locating homes with high radon exposure (above 200 Bq m-3 and improving these, and of protecting future houses. The purpose of this paper is to calculate the costs and the effects of this intervention. Methods: We performed a cost-effect analysis from the perspective of the society, followed by an uncertainty and sensitivity analysis. The distribution of radon levels in Norwegian homes is lognormal with mean=74.5 Bq/m3, and 7.6% above 200 Bq/m3. Results: The preventable attributable fraction of radon on lung cancer was 3.8% (95% uncertainty interval: 0.6%, 8.3%. In cumulative present values the intervention would cost $238 (145, 310 million and save 892 (133, 1981 lives, each life saved costs $0.27 (0.09, 0.9 million. The cost-effect ratio was sensitive to the radon risk, the radon exposure distribution, and the latency period of lung cancer. Together these three parameters explained 90% of the variation in the cost-effect ratio. Conclusions: Reducing the radon concentration in present and future homes to below 200 Bq/m3 will cost $0.27 (0.09, 0.9 million per life saved. The uncertainty in the estimated cost per life is large, mainly due to uncertainty in the risk of lung cancer from radon. Based on estimates from road construction, the Norwegian society has been willing to pay $1 million to save a life. We therefore conclude that the intervention against radon in homes is justifiable. The willingness to pay is also larger that the upper uncertainty limit of the cost per life. Our conclusion is therefore robust against the uncertainties in the parameters.

  9. Realisation of a calibration chamber for radon in the air and establishment of a system for measuring radon in water

    International Nuclear Information System (INIS)

    Sassi, Nedra

    2011-01-01

    Radon is a radioactive gas that is naturally produced from the decay of radium. The main source of radon found in the earth's crust caused by the presence of a series of uranium (222 isotope of radon) and a series of thorium (220 isotope of radon) therein. We have optimized a new radon calibration chamber by developing an electronic system controlled by a PIC 16F877 microcontroller type to manage the various functions of the room. Several electronic circuits were developed to manage multiple functions such as pressure, temperature and controls motors and solenoids. This system can also be interfaced with a computer through programs such as LabView or Matlab.

  10. Mechanisms of radon injury

    International Nuclear Information System (INIS)

    Cross, F.T.

    1988-01-01

    In this new project, they conduct molecular, cellular and whole-animal research relevant to understanding the inhalation toxicology of radon and radon-daughter exposures. The work specifically addresses the exposure-rate effect in radon-daughter carcinogenesis; the induction-promotion relationships associated with exposure to radon and cigarette-smoke mixtures; the role of oncogenes in radon-induced cancers; the effects of radon on DNA as well as on DNA repair processes; and the involvement of growth factors and their receptors in radon-induced carcinogenesis. Preliminary experiments showed that oncogenes are activated in radon-induced lung tumors. They have therefore begun further exposures pertinent to the oncogene and growth-factor studies. An in vitro radon cellular-exposure system was designed, and cell exposures were initiated. Initiation-promotion-initiation studies with radon and cigarette-smoke mixtures have also begun; and they are compiling a radon health-effects bibliography

  11. Determination of Radon-222 and Thoron Concentration in Decorative Stone Warehouses Indoor Air and the Received Effective Dose by Staff

    Directory of Open Access Journals (Sweden)

    Amir Hossein Mahvi

    2015-06-01

    Full Text Available Background: Radon is a colorless, odorless, and radioactive gas that can be emitted from decorative stones such as granite, marble, etc. Inhaling radon gas in a long period may cause for incidence of lung cancer among peoples. Material and Methods: In this cross-sectional descriptive study, Radon 222 and Thoron concentrations in background and indoor air were measured in four decorative stones warehouse using portable radon meter(RTM1688-2 model. Totally, 24 samples of 24- hours concentrations in indoor air and 24 samples of 4-hours concentrations of Radon 222 and thoron in the background air at three stages were measured. Then, received effective dose of Radon 222 and Thoron was calculated by UNSCEAR equations. Results: The mean radon concentrations for indoor and background air were 74±37 and 34±16 Bq/m3, respectively. The mean radon concentrations for indoor air in decorative stones warehouses for DSW1, DSW2, DSW3 and DSW4 were 72.50±34, 98.25±43, 34.42±18 and 88.92±51 Bq/m3, respectively. The received effective dose mean of Radon 222 and Thoron by the staff at 8 working hours was 0.53±0.18 and 0.05±0.03 mSv/y and in 16 working hours was 1.05±0.36 and 0.11±0.07 mSv/y, respectively. Generally, the mean received effective dose by staff from Radon at 8 and 16 working hours was 0.58±0.2  and 1.16±0.41 mSv/y, respectively. Conclusions: Radon concentration mean in indoor air and the received effective dose mean by staff was lower than the standards level. Decorative stone warehouses were the resources for accumulation of Radon gas that can be reduced by corrective actions.

  12. Field demonstrations of radon adsorption units

    International Nuclear Information System (INIS)

    Abrams, R.F.

    1989-01-01

    Four radon gas removal units have been installed in homes in the Northeast U.S. These units utilize dynamic adsorption of the radon gas onto activated charcoal to remove the radon from room air. Two beds of charcoal are used so that one bed removes radon while the second bed is regenerated using outdoor air in a unique process. The beds reverse at the end of a predetermined cycle time, providing continuous removal of radon from the room air. The process and units have undergone extensive development work in the laboratory as well as in homes