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Sample records for v-line radon transform

  1. New properties of the V-line Radon transform and their imaging applications

    International Nuclear Information System (INIS)

    Truong, T T; Nguyen, M K

    2015-01-01

    This paper reports on new aspects of the so-called V-line Radon transforms (RTs) complementing those reported in an earlier work. These new properties are nicely uncovered and described with Cartesian coordinates. In particular, we show that the V-line RT belongs to the class of RTs on curves in the plane which can be mapped onto the standard RT on straight lines and thereby are fully characterizable and invertible. Next, we show that the effect of geometric inversion on the V-line RT is to produce a new RT on a pair of supplementary circular arcs, which provides a new access to image reconstruction in the so-called Norton's modality of Compton scatter tomography, a front runner in the race for alternatives to current emission imaging. (paper)

  2. Inversion algorithms for the spherical Radon and cosine transform

    International Nuclear Information System (INIS)

    Louis, A K; Riplinger, M; Spiess, M; Spodarev, E

    2011-01-01

    We consider two integral transforms which are frequently used in integral geometry and related fields, namely the spherical Radon and cosine transform. Fast algorithms are developed which invert the respective transforms in a numerically stable way. So far, only theoretical inversion formulae or algorithms for atomic measures have been derived, which are not so important for applications. We focus on two- and three-dimensional cases, where we also show that our method leads to a regularization. Numerical results are presented and show the validity of the resulting algorithms. First, we use synthetic data for the inversion of the Radon transform. Then we apply the algorithm for the inversion of the cosine transform to reconstruct the directional distribution of line processes from finitely many intersections of their lines with test lines (2D) or planes (3D), respectively. Finally we apply our method to analyse a series of microscopic two- and three-dimensional images of a fibre system

  3. The radon transform. Theory and implementation

    International Nuclear Information System (INIS)

    Toft, P.

    1996-01-01

    The subject of this Ph.D. thesis is the mathematical Radon transform, which is well suited for curve detection in digital images, and for reconstruction of tomography images. The thesis is divided into two main parts. Part I describes the Radon- and the Hough-transform and especially their discrete approximations with respect to curve parameter detection in digital images. The sampling relationships of the Radon transform is reviewed from a digital signal processing point of view. The discrete Radon transform is investigated for detection of curves, and aspects regarding the performance of the Radon transform assuming various types of noise is covered. Furthermore, a new fast scheme for estimating curve parameters is presented. Part II of the thesis describes the inverse Radon transform in 2D and 3D with focus on reconstruction of tomography images. Some of the direct reconstruction schemes are analyzed, including their discrete implementation. Furthermore, several iterative reconstruction schemes based on linear algebra are reviewed and applied for reconstruction of Positron Emission Tomography (PET) images. A new and very fast implementation of 2D iterative reconstruction methods is devised. In a more practical oriented chapter, the noise in PET images is modelled from a very large number of measurements. Several packagers for Radon- and Hough-transform based curve detection and direct/iterative 2D and 3D reconstruction have been developed and provided for free. (au) 140 refs

  4. Radon-Wigner transform for optical field analysis

    NARCIS (Netherlands)

    Alieva, T.; Bastiaans, M.J.; Nijhawan, O.P.; Gupta, A.K.; Musla, A.K.; Singh, Kehar

    1998-01-01

    The Radon-Wigner transform, associated with the intensity distribution in the fractional Fourier transform system, is used for the analysis of complex structures of coherent as well as partially coherent optical fields. The application of the Radon-Wigner transform to the analysis of fractal fields

  5. Radon transformation on reductive symmetric spaces:Support theorems

    DEFF Research Database (Denmark)

    Kuit, Job Jacob

    2013-01-01

    We introduce a class of Radon transforms for reductive symmetric spaces, including the horospherical transforms, and derive support theorems for these transforms. A reductive symmetric space is a homogeneous space G/H for a reductive Lie group G of the Harish-Chandra class, where H is an open sub...... is based on the relation between the Radon transform and the Fourier transform on G/H, and a Paley–Wiener-shift type argument. Our results generalize the support theorem of Helgason for the Radon transform on a Riemannian symmetric space....

  6. A fast butterfly algorithm for generalized Radon transforms

    KAUST Repository

    Hu, Jingwei; Fomel, Sergey; Demanet, Laurent; Ying, Lexing

    2013-01-01

    Generalized Radon transforms, such as the hyperbolic Radon transform, cannot be implemented as efficiently in the frequency domain as convolutions, thus limiting their use in seismic data processing. We have devised a fast butterfly algorithm

  7. Nonlinear Radon Transform Using Zernike Moment for Shape Analysis

    Directory of Open Access Journals (Sweden)

    Ziping Ma

    2013-01-01

    Full Text Available We extend the linear Radon transform to a nonlinear space and propose a method by applying the nonlinear Radon transform to Zernike moments to extract shape descriptors. These descriptors are obtained by computing Zernike moment on the radial and angular coordinates of the pattern image's nonlinear Radon matrix. Theoretical and experimental results validate the effectiveness and the robustness of the method. The experimental results show the performance of the proposed method in the case of nonlinear space equals or outperforms that in the case of linear Radon.

  8. A fast butterfly algorithm for generalized Radon transforms

    KAUST Repository

    Hu, Jingwei

    2013-06-21

    Generalized Radon transforms, such as the hyperbolic Radon transform, cannot be implemented as efficiently in the frequency domain as convolutions, thus limiting their use in seismic data processing. We have devised a fast butterfly algorithm for the hyperbolic Radon transform. The basic idea is to reformulate the transform as an oscillatory integral operator and to construct a blockwise lowrank approximation of the kernel function. The overall structure follows the Fourier integral operator butterfly algorithm. For 2D data, the algorithm runs in complexity O(N2 log N), where N depends on the maximum frequency and offset in the data set and the range of parameters (intercept time and slowness) in the model space. From a series of studies, we found that this algorithm can be significantly more efficient than the conventional time-domain integration. © 2013 Society of Exploration Geophysicists.

  9. Mixed Norm Estimate for Radon Transform on Weighted $ L^ p ...

    Indian Academy of Sciences (India)

    We will discuss about the mapping property of Radon transform on L p spaces with power weight. It will be shown that the Pitt's inequality together with the weighted version of Hardy–Littlewood–Sobolev lemma imply weighted inequality for the Radon transform.

  10. Analysis of separation test for automatic brake adjuster based on linear radon transformation

    Science.gov (United States)

    Luo, Zai; Jiang, Wensong; Guo, Bin; Fan, Weijun; Lu, Yi

    2015-01-01

    The linear Radon transformation is applied to extract inflection points for online test system under the noise conditions. The linear Radon transformation has a strong ability of anti-noise and anti-interference by fitting the online test curve in several parts, which makes it easy to handle consecutive inflection points. We applied the linear Radon transformation to the separation test system to solve the separating clearance of automatic brake adjuster. The experimental results show that the feature point extraction error of the gradient maximum optimal method is approximately equal to ±0.100, while the feature point extraction error of linear Radon transformation method can reach to ±0.010, which has a lower error than the former one. In addition, the linear Radon transformation is robust.

  11. Radon transformation on reductive symmetric spaces: support theorems

    NARCIS (Netherlands)

    Kuit, J.J.|info:eu-repo/dai/nl/313872589

    2011-01-01

    In this thesis we introduce a class of Radon transforms for reductive symmetric spaces, including the horospherical transforms, and study some of their properties. In particular we obtain a generalization of Helgason's support theorem for the horospherical transform on a Riemannian symmetric space.

  12. Analytic image reconstruction in PVI using the 3D radon transform

    International Nuclear Information System (INIS)

    Staxyk, M.W.; Rogers, J.G.

    1992-01-01

    This paper reports that algorithms have been derived for three dimensional image reconstruction in positron volume imaging (PVI) using the inversion of the three dimensional Radon Transform (RT). The RT is formed by histogramming events into the planes in which they lie rather than along lines as in the X-ray Transform (XT). The authors show the transformation between the RT and the XT and using this relationship they describe a fast backprojection method for the RT in which the computation time is found to be up to 20 times faster with the new algorithm. Monte Carlo simulations show that statistical noise levels in images reconstructed from complete projections with the new RT algorithm are comparable to those obtained using the Fourier Transform (FT) inversion of the XT

  13. Seismic Shear Energy Reflection By Radon-Fourier Transform

    Directory of Open Access Journals (Sweden)

    Malik Umairia

    2016-01-01

    Full Text Available Seismic waves split in an anisotropic medium, instead of rotating horizontal component to principal direction, Radon-Fourier is derived to observe the signature of shear wave reflection. Synthetic model with fracture is built and discretized using finite difference scheme for spatial and time domain. Common depth point (CDP with single shot gives traces and automatic gain is preprocessed before Radon Transform (RT, a filtering technique gives radon domain. It makes easier to observe fractures at specific incidence and improves its quality in some way by removing the noise. A comparison of synthetic data and BF-data is performed on the basis of root means square error (RMS values. The RMS error is minimum at the 10th trace in radon domain.

  14. Quick, sensitive serial NMR experiments with Radon transform.

    Science.gov (United States)

    Dass, Rupashree; Kasprzak, Paweł; Kazimierczuk, Krzysztof

    2017-09-01

    The Radon transform is a potentially powerful tool for processing the data from serial spectroscopic experiments. It makes it possible to decode the rate at which frequencies of spectral peaks shift under the effect of changing conditions, such as temperature, pH, or solvent. In this paper we show how it also improves speed and sensitivity, especially in multidimensional experiments. This is particularly important in the case of low-sensitivity techniques, such as NMR spectroscopy. As an example, we demonstrate how Radon transform processing allows serial measurements of 15 N-HSQC spectra of unlabelled peptides that would otherwise be infeasible. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Using the generalized Radon transform for detection of curves in noisy images

    DEFF Research Database (Denmark)

    Toft, Peter Aundal

    1996-01-01

    In this paper the discrete generalized Radon transform will be investigated as a tool for detection of curves in noisy digital images. The discrete generalized Radon transform maps an image into a parameter domain, where curves following a specific parameterized curve form will correspond to a peak...

  16. Development of an on-line radon monitoring apparatus and design of the on-line radon monitoring platform based on CAN bus

    International Nuclear Information System (INIS)

    Guo Huiping; Lu Ning; Shang Aiguo; Zhou Chunlin; Chen Yingfen; Yu Hongwei

    2004-12-01

    For actual demand, an idea of 'on-line monitoring' is put forward as a way of radon monitoring, instead of traditional so called 'off-line monitoring'. In this way, the apparatus has some automatic functions such as continuous monitoring, real-time alarm; thereby, there is no need for operators' intervention in each monitoring process. With technique of hardware and software design in automation's field, the authors have successfully developed the prototype and finished the scale of it in a standard radon-chamber. This apparatus is composed of detector part and secondary-instrument. The detector part is made up of a passive diffusion collecting chamber, high voltage static electricity, semiconductor detector, charge-sensitive preamplifier and forming circuit. The secondary-instrument is actually a micro-controller system, which consists of a single-chip micro-controller cored measure-controlling unit, display unit, printing unit and alarming unit. Taking this apparatus as a cell, a 'on-line Radon Monitoring Platform' based on CAN bus has been put forward, which can realize multi-points environmental radioactivity real-time monitoring radioactivity and data process. (authors)

  17. Detection of Blood Vessels in Color Fundus Images using a Local Radon Transform

    Directory of Open Access Journals (Sweden)

    Reza Pourreza

    2010-09-01

    Full Text Available Introduction: This paper addresses a method for automatic detection of blood vessels in color fundus images which utilizes two main tools: image partitioning and local Radon transform. Material and Methods: The input images are firstly divided into overlapping windows and then the Radon transform is applied to each. The maximum of the Radon transform in each window corresponds to the probable available sub-vessel. To verify the detected sub-vessel, the maximum is compared with a predefined threshold. The verified sub-vessels are reconstructed using the Radon transform information. All detected and reconstructed sub-vessels are finally combined to make the final vessel tree. Results: The algorithm’s performance was evaluated numerically by applying it to 40 images of DRIVE database, a standard retinal image database. The vessels were extracted manually by two physicians. This database was used to test and compare the available and proposed algorithms for vessel detection in color fundus images. By comparing the output of the algorithm with the manual results, the two parameters TPR and FPR were calculated for each image and the average of TPRs and FPRs were used to plot the ROC curve. Discussion and Conclusion: Comparison of the ROC curve of this algorithm with other algorithms demonstrated the high achieved accuracy. Beside the high accuracy, the Radon transform which is integral-based makes the algorithm robust against noise.

  18. Desk games digitalization using radon transformation and color ...

    African Journals Online (AJOL)

    Desk games digitalization using radon transformation and color segmentation. M Horacek, L Beran, L Rejfek. Abstract. The research is focused on real-time digitalization of board games. ... AJOL African Journals Online. HOW TO USE AJOL.

  19. Multi-resolution inversion algorithm for the attenuated radon transform

    KAUST Repository

    Barbano, Paolo Emilio; Fokas, Athanasios S.

    2011-01-01

    We present a FAST implementation of the Inverse Attenuated Radon Transform which incorporates accurate collimator response, as well as artifact rejection due to statistical noise and data corruption. This new reconstruction procedure is performed

  20. Inversion of the conical Radon transform with vertices on a surface of revolution arising in an application of a Compton camera

    International Nuclear Information System (INIS)

    Moon, Sunghwan

    2017-01-01

    A Compton camera has been introduced for use in single photon emission computed tomography to improve the low efficiency of a conventional gamma camera. In general, a Compton camera brings about the conical Radon transform. Here we consider a conical Radon transform with the vertices on a rotation symmetric set with respect to a coordinate axis. We show that this conical Radon transform can be decomposed into two transforms: the spherical sectional transform and the weighted fan beam transform. After finding inversion formulas for these two transforms, we provide an inversion formula for the conical Radon transform. (paper)

  1. Radon removal from gaseous xenon with activated charcoal

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K.; Hieda, K.; Hiraide, K.; Hirano, S.; Kishimoto, Y.; Kobayashi, K.; Koshio, Y. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Liu, J.; Martens, K. [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Moriyama, S. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Nakahata, M. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishiie, H.; Ogawa, H.; Sekiya, H.; Shinozaki, A. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Suzuki, Y. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Takachio, O.; Takeda, A.; Ueshima, K.; Umemoto, D. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); and others

    2012-01-01

    Many low background experiments using xenon need to remove radioactive radon to improve their sensitivities. However, no method of continually removing radon from xenon has been described in the literature. We studied a method to remove radon from xenon gas through an activated charcoal trap. From our measurements we infer a linear relationship between the mean propagation velocity v{sub Rn} of radon and v{sub Xe} of xenon in the trap with v{sub Rn}/v{sub Xe}=(0.96{+-}0.10) Multiplication-Sign 10{sup -3} at -85 Degree-Sign C. As the mechanism for radon removal in this charcoal trap is its decay, knowledge of this parameter allows us to design an efficient radon removal system for the XMASS experiment. The verification of this system found that it reduces radon by a factor of 0.07, which is in line with its expected average retention time of 14.8 days for radon.

  2. Robust Image Hashing Using Radon Transform and Invariant Features

    Directory of Open Access Journals (Sweden)

    Y.L. Liu

    2016-09-01

    Full Text Available A robust image hashing method based on radon transform and invariant features is proposed for image authentication, image retrieval, and image detection. Specifically, an input image is firstly converted into a counterpart with a normalized size. Then the invariant centroid algorithm is applied to obtain the invariant feature point and the surrounding circular area, and the radon transform is employed to acquire the mapping coefficient matrix of the area. Finally, the hashing sequence is generated by combining the feature vectors and the invariant moments calculated from the coefficient matrix. Experimental results show that this method not only can resist against the normal image processing operations, but also some geometric distortions. Comparisons of receiver operating characteristic (ROC curve indicate that the proposed method outperforms some existing methods in classification between perceptual robustness and discrimination.

  3. Development of an on-line radon monitoring system

    International Nuclear Information System (INIS)

    Guo Huiping; Shang Aiguo; Liu Junfeng; Zhou Chunlin; Di Yuming

    2004-01-01

    Of the actual demand by the strategic missile troops, the author has successfully developed a specially designed passive diffusion collecting chamber to collect the decay products of radon by high voltage static electricity, and using the single-chip microcomputer to reckon the radon concentration in air, which is actually a portable, continuous and automatic on-line monitoring instrument. It was made into a four-slot standard plug-in board of a NIM, and it functions as auto data memory, data process, display, over-threshold alarming and so on. (authors)

  4. Attenuated radon transform: theory and application in medicine and biology

    Energy Technology Data Exchange (ETDEWEB)

    Gullberg, G.T.

    1979-06-01

    A detailed analysis is given of the properties of the attenuated Radon transform and of how increases in photon attenuation influence the numerical accuracy and computation efficiency of iterative and convolution algorithms used to determine its inversion. The practical applications for this work involve quantitative assessment of the distribution of injected radiopharmaceuticals and radionuclides in man and animals for basic physiological and biochemical studies as well as clinical studies in nuclear medicine. A mathematical structure is developed using function theory and the theory of linear operators on Hilbert spaces which lends itself to better understanding the spectral properties of the attenuated Radon transform. The continuous attenuated Radon transform reduces to a matrix operator for discrete angular and lateral sampling, and the reconstruction problem reduces to a system of linear equations. For the situation of variable attenuation coefficient frequently found in nuclear medicine applications of imaging the heart and chest, the procedure developed in this thesis involves iterative techniques of performing the generalized inverse. For constant attenuation coefficient less than 0.15 cm/sup -1/, convolution methods can reliably reconstruct a 30 cm object with 0.5 cm resolution. However, for high attenuation coefficients or for the situation where there is variable attenuation such as reconstruction of distribution of isotopes in the heart, iterative techniques developed in this thesis give the best results. (ERB)

  5. Invariant object recognition based on the generalized discrete radon transform

    Science.gov (United States)

    Easley, Glenn R.; Colonna, Flavia

    2004-04-01

    We introduce a method for classifying objects based on special cases of the generalized discrete Radon transform. We adjust the transform and the corresponding ridgelet transform by means of circular shifting and a singular value decomposition (SVD) to obtain a translation, rotation and scaling invariant set of feature vectors. We then use a back-propagation neural network to classify the input feature vectors. We conclude with experimental results and compare these with other invariant recognition methods.

  6. Limited Data Problems for the Generalized Radon Transform in Rn

    DEFF Research Database (Denmark)

    Frikel, Jürgen; Quinto, Eric Todd

    2016-01-01

    We consider the generalized Radon transform (defined in terms of smooth weight functions) on hyperplanes in Rn. We analyze general filtered backprojection type reconstruction methods for limited data with filters given by general pseudodifferential operators. We provide microlocal characterizations...

  7. Prediction of lung cells oncogenic transformation for induced radon progeny alpha particles using sugarscape cellular automata.

    Science.gov (United States)

    Baradaran, Samaneh; Maleknasr, Niaz; Setayeshi, Saeed; Akbari, Mohammad Esmaeil

    2014-01-01

    Alpha particle irradiation from radon progeny is one of the major natural sources of effective dose in the public population. Oncogenic transformation is a biological effectiveness of radon progeny alpha particle hits. The biological effects which has caused by exposure to radon, were the main result of a complex series of physical, chemical, biological and physiological interactions. The cellular and molecular mechanisms for radon-induced carcinogenesis have not been clear yet. Various biological models, including cultured cells and animals, have been found useful for studying the carcinogenesis effects of radon progeny alpha particles. In this paper, sugars cape cellular automata have been presented for computational study of complex biological effect of radon progeny alpha particles in lung bronchial airways. The model has included mechanism of DNA damage, which has been induced alpha particles hits, and then formation of transformation in the lung cells. Biomarkers were an objective measure or evaluation of normal or abnormal biological processes. In the model, the metabolism rate of infected cell has been induced alpha particles traversals, as a biomarker, has been followed to reach oncogenic transformation. The model results have successfully validated in comparison with "in vitro oncogenic transformation data" for C3H 10T1/2 cells. This model has provided an opportunity to study the cellular and molecular changes, at the various stages in radiation carcinogenesis, involving human cells. It has become well known that simulation could be used to investigate complex biomedical systems, in situations where traditional methodologies were difficult or too costly to employ.

  8. Imaging ultrasonic dispersive guided wave energy in long bones using linear radon transform.

    Science.gov (United States)

    Tran, Tho N H T; Nguyen, Kim-Cuong T; Sacchi, Mauricio D; Le, Lawrence H

    2014-11-01

    Multichannel analysis of dispersive ultrasonic energy requires a reliable mapping of the data from the time-distance (t-x) domain to the frequency-wavenumber (f-k) or frequency-phase velocity (f-c) domain. The mapping is usually performed with the classic 2-D Fourier transform (FT) with a subsequent substitution and interpolation via c = 2πf/k. The extracted dispersion trajectories of the guided modes lack the resolution in the transformed plane to discriminate wave modes. The resolving power associated with the FT is closely linked to the aperture of the recorded data. Here, we present a linear Radon transform (RT) to image the dispersive energies of the recorded ultrasound wave fields. The RT is posed as an inverse problem, which allows implementation of the regularization strategy to enhance the focusing power. We choose a Cauchy regularization for the high-resolution RT. Three forms of Radon transform: adjoint, damped least-squares, and high-resolution are described, and are compared with respect to robustness using simulated and cervine bone data. The RT also depends on the data aperture, but not as severely as does the FT. With the RT, the resolution of the dispersion panel could be improved up to around 300% over that of the FT. Among the Radon solutions, the high-resolution RT delineated the guided wave energy with much better imaging resolution (at least 110%) than the other two forms. The Radon operator can also accommodate unevenly spaced records. The results of the study suggest that the high-resolution RT is a valuable imaging tool to extract dispersive guided wave energies under limited aperture. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  9. On artifacts in limited data spherical Radon transform: curved observation surface

    DEFF Research Database (Denmark)

    Barannyk, Lyudmyla L.; Frikel, Jürgen; Nguyen, Linh V.

    2015-01-01

    We study the limited data problem of the spherical Radon transform in two and three-dimensional spaces with general acquisition surfaces. In such situations, it is known that the application of filtered-backprojection reconstruction formulas might generate added artifacts and degrade the quality...

  10. Road Detection by Using a Generalized Hough Transform

    Directory of Open Access Journals (Sweden)

    Weifeng Liu

    2017-06-01

    Full Text Available Road detection plays key roles for remote sensing image analytics. Hough transform (HT is one very typical method for road detection, especially for straight line road detection. Although many variants of Hough transform have been reported, it is still a great challenge to develop a low computational complexity and time-saving Hough transform algorithm. In this paper, we propose a generalized Hough transform (i.e., Radon transform implementation for road detection in remote sensing images. Specifically, we present a dictionary learning method to approximate the Radon transform. The proposed approximation method treats a Radon transform as a linear transform, which then facilitates parallel implementation of the Radon transform for multiple images. To evaluate the proposed algorithm, we conduct extensive experiments on the popular RSSCN7 database for straight road detection. The experimental results demonstrate that our method is superior to the traditional algorithms in terms of accuracy and computing complexity.

  11. Radon in thermal waters and radon risk in chosen thermal water spas in V4 countries - preliminary results

    International Nuclear Information System (INIS)

    Holy, K.; Blahusiak, P.; Muellerova, M.; Grzadziel, D.; Kozak, K.; Mazur, J.; Kovacs, T.; Nagy, E.; Shahrokhi, A.; Neznal, M.; Neznal, M.

    2014-01-01

    The territory of V4 countries is rich in thermal springs. Some boreholes reach a depth of 2000 m and temperatures up to 70 grad C. 222 Rn concentrations in some thermal waters can exceed 1000 Bq/l, however this concentration is not constant. In V4 countries, there is a long tradition in using thermal waters in spa care. In thermal spas, radon is released from the water, and is transported along with its decay products into human respiratory tract, which is potentially harmful to human health. Thus, controlling the levels of radon concentration in thermal waters, homes and workplaces of spas is justified. The aim of this project is the study of radon 222 Rn concentration in thermal waters and in thermal spas in V4 countries. The measurements are carried out a few times during at least one year in order to observe seasonal variability. The obtained results will serve to determine annual effective doses for employees who spend ca. 8 hours a day inside spa buildings. It will be also possible to assess the effective doses for patients (users) of the pools with the highest registered radon concentrations. We carry out measurements in 3 existing thermal water spas in each of the countries: Slovakia, Poland and Hungary, and in 1 thermal water spas in the Czech Republic,according to choice of partners. (authors)

  12. ATTENUATION OF DIFFRACTED MULTIPLES WITH AN APEX-SHIFTED TANGENT-SQUARED RADON TRANSFORM IN IMAGE SPACE

    Directory of Open Access Journals (Sweden)

    Alvarez Gabriel

    2006-12-01

    Full Text Available In this paper, we propose a method to attenuate diffracted multiples with an apex-shifted tangent-squared Radon transform in angle domain common image gathers (ADCIG . Usually, where diffracted multiples are a problem, the wave field propagation is complex and the moveout of primaries and multiples in data space is irregular. The method handles the complexity of the wave field propagation by wave-equation migration provided that migration velocities are reasonably accurate. As a result, the moveout of the multiples is well behaved in the ADCIGs. For 2D data, the apex-shifted tangent-squared Radon transform maps the 2D space image into a 3D space-cube model whose dimensions are depth, curvature and apex-shift distance.
    Well-corrected primaries map to or near the zero curvature plane and specularly-reflected multiples map to or near the zero apex-shift plane. Diffracted multiples map elsewhere in the cube according to their curvature and apex-shift distance. Thus, specularly reflected as well as diffracted multiples can be attenuated simultaneously. This approach is illustrated with a segment of a 2D seismic line over a large salt body in the Gulf of Mexico. It is shown that ignoring the apex shift compromises the attenuation of the diffracted multiples, whereas the approach proposed attenuates both the specularly-reflected and the diffracted multiples without compromising the primaries.

  13. Power-Law Radon-Transformed Superimposed Inverse Filter Synthetic Discriminant Correlator for Facial Recognition

    National Research Council Canada - National Science Library

    Haji-saeed, Bahareh; Khoury, Jed; Woods, Charles L; Kierstead, John

    2008-01-01

    ...) for facial recognition is proposed. In order to avoid spectral overlap and nonlinear crosstalk, superposition of rotationally variant sets of inverse filter Fourier-transformed Radon-processed templates is used to generate the SDF...

  14. Limited-angle three-dimensional reconstructions using Fourier transform iterations and Radon transform iterations

    International Nuclear Information System (INIS)

    Tam, K.C.; Perez-Mendez, V.

    1981-01-01

    The principles of limited-angle reconstruction of space-limited objects using the concepts of allowed cone and missing cone in Fourier space are discussed. The distortion of a point source resulting from setting the Fourier components in the missing cone to zero has been calculated mathematically, and its bearing on the convergence of an iteration scheme involving Fourier transforms has been analyzed in detail. it was found that the convergence rate is fairly insensitive to the position of the point source within the boundary of the object, apart from an edge effect which tends to enhance some parts of the boundary in reconstructing the object. Another iteration scheme involving Radon transforms was introduced and compared to the Fourier transform method in such areas as root mean square error, stability with respect to noise, and computer reconstruction time

  15. Limited-angle 3-D reconstructions using Fourier transform iterations and Radon transform iterations

    International Nuclear Information System (INIS)

    Tam, K.C.; Perez-Mendez, V.

    1979-12-01

    The principles of limited-angle reconstruction of space-limited objects using the concepts of allowed cone and missing cone in Fourier space are discussed. The distortion of a point source resulting from setting the Fourier components in the missing cone to zero was calculated mathematically, and its bearing on the convergence of an iteration scheme involving Fourier transforms was analyzed in detail. It was found that the convergence rate is fairly insensitive to the position of the point source within the boundary of the object, apart from an edge effect that tends to enhance some parts of the boundary in reconstructing the object. Another iteration scheme involving Radon transforms was introduced and compared to the Fourier transform method in such areas as root mean square error, stability with respect to noise, and computer reconstruction time. 8 figures, 2 tables

  16. A complete low cost radon detection system

    International Nuclear Information System (INIS)

    Bayrak, A.; Barlas, E.; Emirhan, E.; Kutlu, Ç.; Ozben, C.S.

    2013-01-01

    Monitoring the 222 Rn activity through the 1200 km long Northern Anatolian fault line, for the purpose of earthquake precursory, requires large number of cost effective radon detectors. We have designed, produced and successfully tested a low cost radon detection system (a radon monitor). In the detector circuit of this monitor, First Sensor PS100-7-CER-2 windowless PIN photodiode and a custom made transempedence/shaping amplifier were used. In order to collect the naturally ionized radon progeny to the surface of the PIN photodiode, a potential of 3500 V was applied between the conductive hemi-spherical shell and the PIN photodiode. In addition to the count rate of the radon progeny, absolute pressure, humidity and temperature were logged during the measurements. A GSM modem was integrated to the system for transferring the measurements from the remote locations to the data process center. - Author-Highlights: • Low cost radon detection. • Integrated GSM modem for early warning of radon anomalies. • Radon detection in environment

  17. 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)

  18. 3-D Discrete Analytical Ridgelet Transform

    OpenAIRE

    Helbert , David; Carré , Philippe; Andrès , Éric

    2006-01-01

    International audience; In this paper, we propose an implementation of the 3-D Ridgelet transform: the 3-D discrete analytical Ridgelet transform (3-D DART). This transform uses the Fourier strategy for the computation of the associated 3-D discrete Radon transform. The innovative step is the definition of a discrete 3-D transform with the discrete analytical geometry theory by the construction of 3-D discrete analytical lines in the Fourier domain. We propose two types of 3-D discrete lines:...

  19. Construction of radon/radon daughter calibraton chamber

    International Nuclear Information System (INIS)

    Fry, J.; Gan, T.H.; Leach, V.A.; Saddlier, J.; Solomon, S.B.; Tam, K.K.; Travis, E.; Wykes, P.

    1983-01-01

    The radon/radon daughter test chamber is a copper lined room 1.65x1.75x2.75m with an effective volume of 8000 litres. The air residence time is controlled by circulating the air in the chamber through absolute filters which remove 99.9% of particulates. Radon is drawn into the chamber from a 17 μCi 226 RaCl source using the pressure differential across the blowers (<3 psi)

  20. NDT applications of the 3D radon transform algorithm for cone beam reconstruction

    International Nuclear Information System (INIS)

    Sire, P.; Grangeat, P.; Lemasson, P.; Molennec, P.; Rizo, P.

    1990-01-01

    The paper describes the authors' 3D X-ray CT algorithm RADON using attenuation measurements acquired with a bidimensional detector. The authors' inversion diagram uses the first derivative of the Radon transform synthesis then its inversion. The potentiality of that new method, particularly for the large aperture, prompted us to develop an optimized software offering convenience and high performances on a modern scientific computer. After a brief recall of the basic principle of X-ray imaging processing, the authors introduce theoretical developments resulting in the present inversion diagram. A general algorithm structure will be proposed afterwards. As a conclusion the authors present the performances and the results obtained with ceramic rotors examination

  1. Parallel plate transmission line transformer

    NARCIS (Netherlands)

    Voeten, S.J.; Brussaard, G.J.H.; Pemen, A.J.M.

    2011-01-01

    A Transmission Line Transformer (TLT) can be used to transform high-voltage nanosecond pulses. These transformers rely on the fact that the length of the pulse is shorter than the transmission lines used. This allows connecting the transmission lines in parallel at the input and in series at the

  2. Multi-resolution inversion algorithm for the attenuated radon transform

    KAUST Repository

    Barbano, Paolo Emilio

    2011-09-01

    We present a FAST implementation of the Inverse Attenuated Radon Transform which incorporates accurate collimator response, as well as artifact rejection due to statistical noise and data corruption. This new reconstruction procedure is performed by combining a memory-efficient implementation of the analytical inversion formula (AIF [1], [2]) with a wavelet-based version of a recently discovered regularization technique [3]. The paper introduces all the main aspects of the new AIF, as well numerical experiments on real and simulated data. Those display a substantial improvement in reconstruction quality when compared to linear or iterative algorithms. © 2011 IEEE.

  3. Performance analysis of a finite radon transform in OFDM system under different channel models

    Energy Technology Data Exchange (ETDEWEB)

    Dawood, Sameer A.; Anuar, M. S.; Fayadh, Rashid A. [School of Computer and Communication Engineering, Universiti Malaysia Perlis (UniMAP) Pauh Putra, 02000 Arau, Parlis (Malaysia); Malek, F.; Abdullah, Farrah Salwani [School of Electrical System Engineering, Universiti Malaysia Perlis (UniMAP) Pauh Putra, 02000 Arau, Parlis (Malaysia)

    2015-05-15

    In this paper, a class of discrete Radon transforms namely Finite Radon Transform (FRAT) was proposed as a modulation technique in the realization of Orthogonal Frequency Division Multiplexing (OFDM). The proposed FRAT operates as a data mapper in the OFDM transceiver instead of the conventional phase shift mapping and quadrature amplitude mapping that are usually used with the standard OFDM based on Fast Fourier Transform (FFT), by the way that ensure increasing the orthogonality of the system. The Fourier domain approach was found here to be the more suitable way for obtaining the forward and inverse FRAT. This structure resulted in a more suitable realization of conventional FFT- OFDM. It was shown that this application increases the orthogonality significantly in this case due to the use of Inverse Fast Fourier Transform (IFFT) twice, namely, in the data mapping and in the sub-carrier modulation also due to the use of an efficient algorithm in determining the FRAT coefficients called the optimal ordering method. The proposed approach was tested and compared with conventional OFDM, for additive white Gaussian noise (AWGN) channel, flat fading channel, and multi-path frequency selective fading channel. The obtained results showed that the proposed system has improved the bit error rate (BER) performance by reducing inter-symbol interference (ISI) and inter-carrier interference (ICI), comparing with conventional OFDM system.

  4. Performance analysis of a finite radon transform in OFDM system under different channel models

    International Nuclear Information System (INIS)

    Dawood, Sameer A.; Anuar, M. S.; Fayadh, Rashid A.; Malek, F.; Abdullah, Farrah Salwani

    2015-01-01

    In this paper, a class of discrete Radon transforms namely Finite Radon Transform (FRAT) was proposed as a modulation technique in the realization of Orthogonal Frequency Division Multiplexing (OFDM). The proposed FRAT operates as a data mapper in the OFDM transceiver instead of the conventional phase shift mapping and quadrature amplitude mapping that are usually used with the standard OFDM based on Fast Fourier Transform (FFT), by the way that ensure increasing the orthogonality of the system. The Fourier domain approach was found here to be the more suitable way for obtaining the forward and inverse FRAT. This structure resulted in a more suitable realization of conventional FFT- OFDM. It was shown that this application increases the orthogonality significantly in this case due to the use of Inverse Fast Fourier Transform (IFFT) twice, namely, in the data mapping and in the sub-carrier modulation also due to the use of an efficient algorithm in determining the FRAT coefficients called the optimal ordering method. The proposed approach was tested and compared with conventional OFDM, for additive white Gaussian noise (AWGN) channel, flat fading channel, and multi-path frequency selective fading channel. The obtained results showed that the proposed system has improved the bit error rate (BER) performance by reducing inter-symbol interference (ISI) and inter-carrier interference (ICI), comparing with conventional OFDM system

  5. Radon: Chemical and physical states of radon progeny. Final technical report

    International Nuclear Information System (INIS)

    Castleman, A.W. Jr.

    1996-01-01

    The evolving chemical and physical form of radon progeny influence their transport to the bioreceptor and the extent to which that receptor can take up these species into various tissues. When first born following radioactive decay processes, the potentially deleterious radon progeny undergo various physical and chemical transformations as they transcend from a highly charged to a neutral state, and interact with various constituents of the environment. These transformations impact on the extent to which the radon progeny become associated with aerosol particles on the one hand, and their ultimate chemical form that is available for uptake in the biosystem, on the other. The program, which originally commenced in 1987, dealt with the basic chemistry and physics of radon progeny and hence impacted on several themes of importance to the DOE/OHER radon program. One of these is dose response, which is governed by the physical forms of the radon progeny, their transport to the bioreceptor and the chemical forms that govern their uptake. The second theme had to do with cellular responses, one of the major issues motivating the work. It is well known that various sizes of ions and molecules are selectively transported across cell membrane to differing degrees. This ultimately has to do with their chemical and physical forms, charge and size. The overall objective of the work was threefold: (1) quantifying the mechanisms and rates of the chemical and physical transformation; (2) ascertaining the ultimate chemical forms, and (3) determining the potential interactions of these chemical species with biological functional groups to ascertain their ultimate transport and incorporation within cells

  6. Series Transmission Line Transformer

    Science.gov (United States)

    Buckles, Robert A.; Booth, Rex; Yen, Boris T.

    2004-06-29

    A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

  7. Parallel Monte Carlo Search for Hough Transform

    Science.gov (United States)

    Lopes, Raul H. C.; Franqueira, Virginia N. L.; Reid, Ivan D.; Hobson, Peter R.

    2017-10-01

    We investigate the problem of line detection in digital image processing and in special how state of the art algorithms behave in the presence of noise and whether CPU efficiency can be improved by the combination of a Monte Carlo Tree Search, hierarchical space decomposition, and parallel computing. The starting point of the investigation is the method introduced in 1962 by Paul Hough for detecting lines in binary images. Extended in the 1970s to the detection of space forms, what came to be known as Hough Transform (HT) has been proposed, for example, in the context of track fitting in the LHC ATLAS and CMS projects. The Hough Transform transfers the problem of line detection, for example, into one of optimization of the peak in a vote counting process for cells which contain the possible points of candidate lines. The detection algorithm can be computationally expensive both in the demands made upon the processor and on memory. Additionally, it can have a reduced effectiveness in detection in the presence of noise. Our first contribution consists in an evaluation of the use of a variation of the Radon Transform as a form of improving theeffectiveness of line detection in the presence of noise. Then, parallel algorithms for variations of the Hough Transform and the Radon Transform for line detection are introduced. An algorithm for Parallel Monte Carlo Search applied to line detection is also introduced. Their algorithmic complexities are discussed. Finally, implementations on multi-GPU and multicore architectures are discussed.

  8. Bayesian image restoration for medical images using radon transform

    International Nuclear Information System (INIS)

    Shouno, Hayaru; Okada, Masato

    2010-01-01

    We propose an image reconstruction algorithm using Bayesian inference for Radon transformed observation data, which often appears in the field of medical image reconstruction known as computed tomography (CT). In order to apply our Bayesian reconstruction method, we introduced several hyper-parameters that control the ratio between prior information and the fidelity of the observation process. Since the quality of the reconstructed image is influenced by the estimation accuracy of these hyper-parameters, we propose an inference method for them based on the marginal likelihood maximization principle as well as the image reconstruction method. We are able to demonstrate a reconstruction result superior to that obtained using the conventional filtered back projection method. (author)

  9. Radon in geological medium

    Energy Technology Data Exchange (ETDEWEB)

    Hricko, J [GEOCOMPLEX, a.s., Bratislava (Slovakia)

    1996-12-31

    The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a{sub v} has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km{sup 2}. The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a{sub v} > 50 kBq/m{sup 3}). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs.

  10. Radon in geological medium

    International Nuclear Information System (INIS)

    Hricko, J.

    1995-01-01

    The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a v has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km 2 . The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a v > 50 kBq/m 3 ). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs

  11. Isotropic-resolution linear-array-based photoacoustic computed tomography through inverse Radon transform

    Science.gov (United States)

    Li, Guo; Xia, Jun; Li, Lei; Wang, Lidai; Wang, Lihong V.

    2015-03-01

    Linear transducer arrays are readily available for ultrasonic detection in photoacoustic computed tomography. They offer low cost, hand-held convenience, and conventional ultrasonic imaging. However, the elevational resolution of linear transducer arrays, which is usually determined by the weak focus of the cylindrical acoustic lens, is about one order of magnitude worse than the in-plane axial and lateral spatial resolutions. Therefore, conventional linear scanning along the elevational direction cannot provide high-quality three-dimensional photoacoustic images due to the anisotropic spatial resolutions. Here we propose an innovative method to achieve isotropic resolutions for three-dimensional photoacoustic images through combined linear and rotational scanning. In each scan step, we first elevationally scan the linear transducer array, and then rotate the linear transducer array along its center in small steps, and scan again until 180 degrees have been covered. To reconstruct isotropic three-dimensional images from the multiple-directional scanning dataset, we use the standard inverse Radon transform originating from X-ray CT. We acquired a three-dimensional microsphere phantom image through the inverse Radon transform method and compared it with a single-elevational-scan three-dimensional image. The comparison shows that our method improves the elevational resolution by up to one order of magnitude, approaching the in-plane lateral-direction resolution. In vivo rat images were also acquired.

  12. Deblending using an improved apex-shifted hyperbolic radon transform based on the Stolt migration operator

    Science.gov (United States)

    Gong, Xiangbo; Feng, Fei; Jiao, Xuming; Wang, Shengchao

    2017-10-01

    Simultaneous seismic source separation, also known as deblending, is an essential process for blended acquisition. With the assumption that the blending noise is coherent in the common shot domain but is incoherent in other domains, traditional deblending methods are commonly performed in the common receiver, common midpoint or common offset domain. In this paper, we propose an improved apex-shifted hyperbolic radon transform (ASHRT) to deblend directly in the common shot domain. A time-axis stretch strategy named Stolt-stretch is introduced to overcome the limitation of the constant velocity assumption of Stolt-based operators. To improve the sparsity in the transform domain, a total variation (TV) norm inversion is implemented to enhance the energy convergence in the radon panel. Because of highly efficient Stolt migration and the demigration operator in the frequency-wavenumber domain, as well as the flexible geometry condition of the source-receiver, this approach is quite suitable for quality control (QC) during streamer acquisition. The synthetic and field examples demonstrate that our proposition is robust and efficient.

  13. Least-squares reverse time migration with radon preconditioning

    KAUST Repository

    Dutta, Gaurav

    2016-09-06

    We present a least-squares reverse time migration (LSRTM) method using Radon preconditioning to regularize noisy or severely undersampled data. A high resolution local radon transform is used as a change of basis for the reflectivity and sparseness constraints are applied to the inverted reflectivity in the transform domain. This reflects the prior that for each location of the subsurface the number of geological dips is limited. The forward and the adjoint mapping of the reflectivity to the local Radon domain and back are done through 3D Fourier-based discrete Radon transform operators. The sparseness is enforced by applying weights to the Radon domain components which either vary with the amplitudes of the local dips or are thresholded at given quantiles. Numerical tests on synthetic and field data validate the effectiveness of the proposed approach in producing images with improved SNR and reduced aliasing artifacts when compared with standard RTM or LSRTM.

  14. 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

  15. Radon exhalation of hardening concrete: monitoring cement hydration and prediction of radon concentration in construction site.

    Science.gov (United States)

    Kovler, Konstantin

    2006-01-01

    The unique properties of radon as a noble gas are used for monitoring cement hydration and microstructural transformations in cementitious system. It is found that the radon concentration curve for hydrating cement paste enclosed in the chamber increases from zero (more accurately - background) concentrations, similar to unhydrated cement. However, radon concentrations developed within 3 days in the test chamber containing cement paste were approximately 20 times higher than those of unhydrated cement. This fact proves the importance of microstructural transformations taking place in the process of cement hydration, in comparison with cement grain, which is a time-stable material. It is concluded that monitoring cement hydration by means of radon exhalation method makes it possible to distinguish between three main stages, which are readily seen in the time dependence of radon concentration: stage I (dormant period), stage II (setting and intensive microstructural transformations) and stage III (densification of the structure and drying). The information presented improves our understanding of the main physical mechanisms resulting in the characteristic behavior of radon exhalation in the course of cement hydration. The maximum value of radon exhalation rate observed, when cement sets, can reach 0.6 mBq kg(-1) s(-1) and sometimes exceeds 1.0 mBq kg(-1) s(-1). These values exceed significantly to those known before for cementitious materials. At the same time, the minimum ventilation rate accepted in the design practice (0.5 h(-1)), guarantees that the concentrations in most of the cases will not exceed the action level and that they are not of any radiological concern for construction workers employed in concreting in closed spaces.

  16. Result of the intercomparison exercise on radon measuring instruments and radon detectors 'bev- radon ring 2005'

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, A. [Vienna Univ. of Technology, Atominstitut, Wien (Austria); Maringer, F.J.; Michai, P.; Kreuziger, M. [BEV-Federal Office of Metrology and Surveying, Wien (Austria)

    2006-07-01

    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

  17. Analysis of noise properties of a class of exact methods of inverting the 2-D exponential radon transform

    International Nuclear Information System (INIS)

    Pan, X.; Metz, C.E.

    1995-01-01

    A general approach that the authors proposed elsewhere reveals the intrinsic relationship among methods for inversion of the 2-D exponential Radon transform described by Bellini et al., by Tretiak and Metz, by Hawkins et al., and by Inouye et al. Moreover, the approach provides an infinite class of linear methods for inverting the 2-D exponential Radon transform. In the work reported here, they systematically investigated the noise characteristics of the methods in this class, obtaining analytical forms for the autocovariance and the variance of the images reconstructed by use of various methods. The noise properties of a new quasi-optimal method were then compared theoretically to those of other methods of the class. The analysis demonstrates that the quasi-optimal method achieves smaller global variance in the reconstructed images than do the other methods of the class. Extensive numerical simulation studies confirm this prediction

  18. On a problem of reconstruction of a discontinuous function by its Radon transform

    Energy Technology Data Exchange (ETDEWEB)

    Derevtsov, Evgeny Yu.; Maltseva, Svetlana V.; Svetov, Ivan E. [Sobolev Institute of Mathematics of SB RAS, 630090, Novosibirsk (Russian Federation); Novosibirsk State University, 630090, Novosibirsk (Russian Federation); Sultanov, Murat A. [H. A. Yassawe International Kazakh-Turkish University, 161200, Turkestan (Kazakhstan)

    2016-08-10

    A problem of reconstruction of a discontinuous function by its Radon transform is considered. One of the approaches to the numerical solution for the problem consists in the next sequential steps: a visualization of a set of breaking points; an identification of this set; a determination of jump values; an elimination of discontinuities. We consider three of listed problems except the problem of jump values. The problems are investigated by mathematical modeling using numerical experiments. The results of simulation are satisfactory and allow to hope for the further development of the approach.

  19. Radon house doctor

    International Nuclear Information System (INIS)

    Nitschke, I.A.; Brennan, T.; Wadach, J.B.; O'Neil, R.

    1986-01-01

    The term house doctor may be generalized to include persons skilled in the use of instruments and procedures necessary to identify, diagnose, and correct indoor air quality problems as well as energy, infiltration, and structural problems in houses. A radon house doctor would then be a specialist in radon house problems. Valuable experience in the skills necessary to be developed by radon house doctors has recently been gained in an extensive radon monitoring and mitigation program in upstate New York sponsored by Niagara Mohawk Power Corporation and the New York State Energy Research and Development Authority. These skills, to be described in detail in this paper, include: (i) the use of appropriate instruments, (ii) the evaluation of the symptoms of a radon-sick house, (iii) the diagnostic procedures required to characterize radon sources in houses, (iv) the prescription procedures needed to specify treatment of the problem, (v) the supervision of the implementation of the treatment program, (vi) the check-up procedures required to insure the house cured of radon problems. 31 references, 3 tables

  20. γ-Ray spectrometry of radon in water and the role of radon to representatively sample aquifers

    International Nuclear Information System (INIS)

    Talha, S.A.; Lindsay, R.; Newman, R.T.; Meijer, R.J. de; Maleka, P.P.; Hlatshwayo, I.N.; Mlwilo, N.A.; Mohanty, A.K.

    2008-01-01

    Measurement of radon in water by γ-ray spectrometry using a HPGe detector has been investigated to determine aquifer characteristics. The radon activity concentration is determined by taking the weighted average of the concentrations derived from γ-ray lines associated with 214 Pb and 214 Bi decay. The role of accurate radon data to representatively sample aquifers was also investigated by studying a semi-cased borehole. A simplified physical model describing the change of radon concentration with the pumping time, reproduces the data and predicts the time for representative sampling of the aquifer

  1. An inversion formula for the exponential Radon transform in spatial domain with variable focal-length fan-beam collimation geometry

    International Nuclear Information System (INIS)

    Wen Junhai; Liang Zhengrong

    2006-01-01

    Inverting the exponential Radon transform has a potential use for SPECT (single photon emission computed tomography) imaging in cases where a uniform attenuation can be approximated, such as in brain and abdominal imaging. Tretiak and Metz derived in the frequency domain an explicit inversion formula for the exponential Radon transform in two dimensions for parallel-beam collimator geometry. Progress has been made to extend the inversion formula for fan-beam and varying focal-length fan-beam (VFF) collimator geometries. These previous fan-beam and VFF inversion formulas require a spatially variant filtering operation, which complicates the implementation and imposes a heavy computing burden. In this paper, we present an explicit inversion formula, in which a spatially invariant filter is involved. The formula is derived and implemented in the spatial domain for VFF geometry (where parallel-beam and fan-beam geometries are two special cases). Phantom simulations mimicking SPECT studies demonstrate its accuracy in reconstructing the phantom images and efficiency in computation for the considered collimator geometries

  2. Diagnostics for the 1.5 GeV Transport Line at the NSRRC

    CERN Document Server

    Hu, K H; Hsu, K T; Kuo, C H; Lee, D; Wang, C J; Yang, Y T

    2005-01-01

    The extracted 1.5 GeV electron beams from the booster synchrotron are transported via a transport line and injected into the storage ring. This booster-to-storage ring transport line equipped with stripline beam positions monitors, integrated current transformers, fast current transformer, and screen monitors. Commercial log-ratio BPM electronics were adopted to process the 500MHz bunch signal directly. The position of the passing beam is digitized by VME analog interface. The transmission efficiency is measured by integrated current transformer. Screen monitors are used to support routine operation. This report summary the system architecture, software tools, and performance of the BTS diagnostics.

  3. Least-squares reverse time migration with radon preconditioning

    KAUST Repository

    Dutta, Gaurav; Agut, Cyril; Giboli, Matteo; Williamson, Paul

    2016-01-01

    domain and back are done through 3D Fourier-based discrete Radon transform operators. The sparseness is enforced by applying weights to the Radon domain components which either vary with the amplitudes of the local dips or are thresholded at given

  4. Performance of nonsynchronous noncommensurate impedance transformers in comparison to tapered line transformers

    DEFF Research Database (Denmark)

    Kim, Kseniya; Zhurbenko, Vitaliy; Johansen, Tom Keinicke

    2012-01-01

    to a traditional tapered line impedance transformer. The increase in bandwidth of nonsynchronous noncommensurate impedance transformers typically leads to shortening the transformer length, which makes the transformer attractive for applications, where a wide operating band and high transformation ratios...

  5. 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

  6. Texture analysis of clinical radiographs using radon transform on a local scale for differentiation between post-menopausal women with and without hip fracture

    Science.gov (United States)

    Boehm, Holger F.; Körner, Markus; Baumert, Bernhard; Linsenmaier, Ulrich; Reiser, Maximilian

    2011-03-01

    Osteoporosis is a chronic condition characterized by demineralization and destruction of bone tissue. Fractures associated with the disease are becoming an increasingly relevant issue for public health institutions. Prediction of fracture risk is a major focus research and, over the years, has been approched by various methods. Still, bone mineral density (BMD) obtained by dual-energy X-ray absorptiometry (DXA) remains the clinical gold-standard for diagnosis and follow-up of osteoporosis. However, DXA is restricted to specialized diagnostic centers and there exists considerable overlap in BMD results between populations of individuals with and without fractures. Clinically far more available than DXA is conventional x-ray imaging depicting trabecular bone structure in great detail. In this paper, we demonstrate that bone structure depicted by clinical radiographs can be analysed quantitatively by parameters obtained from the Radon Transform (RT). RT is a global analysis-tool for detection of predefined, parameterized patterns, e.g. straight lines or struts, representing suitable approximations of trabecular bone texture. The proposed algorithm differentiates between patients with and without fractures of the hip by application of various texture-metrics based on the Radon-Transform to standard x-ray images of the proximal femur. We consider three different regions-of-interest in the proximal femur (femoral head, neck, and inter-trochanteric area), and conduct an analysis with respect to correct classification of the fracture status. Performance of the novel approach is compared to DXA. We draw the conclusion that performance of RT is comparable to DXA and may become a useful supplement to densitometry for the prediction of fracture risk.

  7. Multi-year monitoring of radon in boreholes at the Modra geophysical observatory, Slovakia

    International Nuclear Information System (INIS)

    Smetanova, I.; Steinitz, G.; Holy, K.

    2017-01-01

    Long-term radon monitoring was performed in two boreholes, at a depth of 13 m in the 40 m deep V-2 borehole (August 2003 September 2005), and at 3 m depth in the 10 m deep V-3 borehole (August 2003 April 2008). Diurnal, multi-day and annual variations in radon time-series were observed. Daily average of radon activity in V-2 borehole was significantly higher and ranged from 6.5 to 383.7 kBq/m 3 , while in V-3 borehole only between 1.2 and 139.4 kBq/m 3 . The seasonal pattern was more pronounced in V-3 time series, with the maximum occurring from October to March. Multi-day variations (2-10 days) were registered in V-2 and V-3 mostly simultaneously, with higher discrepancy in spring and summer periods, when radon activity in V-3 borehole was low. Diurnal radon variations with two maxima and two minima per day were registered in both boreholes. The influence of meteorological parameters on radon concentrations was investigated. The overall impression is that seasonal variation in radon in V-3 borehole seems to be connected with the temperature variation. Multi-day variations of radon in both boreholes coincided with the atmospheric pressure changes. An increase in radon activity was observed in V-3 borehole after the rainfall in spring and summer seasons. (authors)

  8. On-line Monitoring System for Power Transformers

    Directory of Open Access Journals (Sweden)

    Alexandru HOTEA

    2016-12-01

    Full Text Available Power transformers are the most important and expensive equipment from the electricity transmission system, so it is very important to know the real state of health of such equipment in every moment. De-energizing the power transformer accidentally due to internal defects can generate high costs. Annual maintenance proved to be ineffective in many cases to determine the internal condition of the equipment degradation due to faults rapidly evolving. An On-line Monitoring System for Power Transformers help real-time condition assessment and to detect errors early enough to take action to eliminate or minimize them. After abnormality detected, it is still important to perform full diagnostic tests to determine the exact condition of the equipment. On-line monitoring systems can help increase the level of availability and reliability of power transformers and lower costs of accidental interruption. This paper presents cases studies on several power transformers equipped with on-line monitoring systems from Transelectrica substation.

  9. Automatic Detection of Microaneurysms in Color Fundus Images using a Local Radon Transform Method

    Directory of Open Access Journals (Sweden)

    Hamid Reza Pourreza

    2009-03-01

    Full Text Available Introduction: Diabetic retinopathy (DR is one of the most serious and most frequent eye diseases in the world and the most common cause of blindness in adults between 20 and 60 years of age. Following 15 years of diabetes, about 2% of the diabetic patients are blind and 10% suffer from vision impairment due to DR complications. This paper addresses the automatic detection of microaneurysms (MA in color fundus images, which plays a key role in computer-assisted early diagnosis of diabetic retinopathy. Materials and Methods: The algorithm can be divided into three main steps. The purpose of the first step or pre-processing is background normalization and contrast enhancement of the images. The second step aims to detect candidates, i.e., all patterns possibly corresponding to MA, which is achieved using a local radon transform, Then, features are extracted, which are used in the last step to automatically classify the candidates into real MA or other objects using the SVM method. A database of 100 annotated images was used to test the algorithm. The algorithm was compared to manually obtained gradings of these images. Results: The sensitivity of diagnosis for DR was 100%, with specificity of 90% and the sensitivity of precise MA localization was 97%, at an average number of 5 false positives per image. Discussion and Conclusion: Sensitivity and specificity of this algorithm make it one of the best methods in this field. Using the local radon transform in this algorithm eliminates the noise sensitivity for MA detection in retinal image analysis.

  10. Behavior of radon and its decay products in physical media; Comportamiento de radon y sus productos en medios fisicos

    Energy Technology Data Exchange (ETDEWEB)

    Chavez B, A

    1990-06-15

    This study was carried out to know the radon behavior, it shows some of its decay products of short life, the same as the equations that describe the growth of the activity of each decay product in a source that initially is radon. The study threw results that they are applicable in geology, uranium prospecting, as well as in radiological safety. The use of membranes to filter the decay products of radon and the use of these for protection of the detector, it has opened a new line in the study of the radon. (Author)

  11. 3-D discrete analytical ridgelet transform.

    Science.gov (United States)

    Helbert, David; Carré, Philippe; Andres, Eric

    2006-12-01

    In this paper, we propose an implementation of the 3-D Ridgelet transform: the 3-D discrete analytical Ridgelet transform (3-D DART). This transform uses the Fourier strategy for the computation of the associated 3-D discrete Radon transform. The innovative step is the definition of a discrete 3-D transform with the discrete analytical geometry theory by the construction of 3-D discrete analytical lines in the Fourier domain. We propose two types of 3-D discrete lines: 3-D discrete radial lines going through the origin defined from their orthogonal projections and 3-D planes covered with 2-D discrete line segments. These discrete analytical lines have a parameter called arithmetical thickness, allowing us to define a 3-D DART adapted to a specific application. Indeed, the 3-D DART representation is not orthogonal, It is associated with a flexible redundancy factor. The 3-D DART has a very simple forward/inverse algorithm that provides an exact reconstruction without any iterative method. In order to illustrate the potentiality of this new discrete transform, we apply the 3-D DART and its extension to the Local-DART (with smooth windowing) to the denoising of 3-D image and color video. These experimental results show that the simple thresholding of the 3-D DART coefficients is efficient.

  12. Radon i danske lejeboliger

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Skytte Clausen, Louise

    I denne undersøgelse kortlægges radonindholdet i indeluften og det undersøges, hvordan indholdet af radon i indeluften er fordelt og spredes i en ejendom, og om det er muligt at pege på en bygningsdel eller en bygningskomponent som en spredningsvej for radon i boliger. Boligerne er lejeboliger og...... ligger i etageejendomme, kæde- og rækkehuse tilhørende bygningstyper opført fra 1850 og frem. De udvalgte ejendomme ligger i områder af landet, hvor der ved tidligere undersøgelser har vist sig at være en stor andel af huse med et højt indhold af radon i indeluften. Koncentrationen af radon er målt over...

  13. Radon exhalation rates corrected for leakage and back diffusion – Evaluation of radon chambers and radon sources with application to ceramic tile

    Directory of Open Access Journals (Sweden)

    M. Abo-Elmagd

    2014-10-01

    Full Text Available The natural radon decay, leakage and back diffusion are the main removal processes of radon from its container. Ignoring these processes leads to underestimate the measured value of radon related parameters like exhalation rate and radium content. This work is aimed to evaluate two different radon chambers through determining their leakage rate λv and evaluation of radon source by determine its back diffusion rate λb inside the evaluated radon chambers as well as a small sealed cup. Two different methods are adapted for measuring both the leakage rate and the back diffusion rate. The leakage rate can be determined from the initial slope of the radon decay curve or from the exponential fitting of the whole decay curve. This can be achieved if a continuous monitoring of radon concentration inside the chamber is available. Also, the back diffusion rate is measured by sealing the radon source in the chamber and used the initial slope of the buildup curve to determine λb and therefore the exhalation rate of the source. This method was compared with simple equation for λb based on the ratio of the source to the chamber volume. The obtained results are applied to ceramic tile as an important radon source in homes. The measurement is targeted the ceramic glaze before and after firing as well as the obtained tile after adhere the glaze on the tile main body. Also, six different tile brands from Egyptian market are subjected to the study for comparison.

  14. Possible involvement of MSX-2 homeoprotein in v-ras-induced transformation.

    Science.gov (United States)

    Takahashi, C; Akiyama, N; Kitayama, H; Takai, S; Noda, M

    1997-04-01

    A truncated MSX-2 homeoprotein was found to induce flat reversion when expressed in v-Ki-ras-transformed NIH3T3 cells. Although the expression of endogenous MSX-2 gene is low in most of the normal adult tissues examined, it is frequently activated in carcinoma-derived cell lines. Likewise, the gene is inactive in untransformed cells but is transcriptionally activated after transformation by v-Ki-ras oncogene, suggesting that the intact MSX-2 may play a positive, rather than suppressive, role in cell transformation. To test this possibility, we isolated a full-length human MSX-2 cDNA and tested its activities in two cell systems: fibroblast and myoblast. In NIH3T3 fibroblasts, although the gene by itself failed to confer a transformed phenotype, antisense MSX-2 cDNA as well as truncated MSX-2 cDNA interfered with the transforming activities of both v-Ki-ras and v-raf oncogene. In C2C12 myoblasts, MSX-2 was found to suppress MyoD gene expression, as do activated ras oncogenes, under certain culture conditions, and truncated MSX-2 cDNA was found to inhibit the activities of both MSX-2 and ras in this system as well. Our findings not only suggest that the truncated version MSX-2 may act as a dominant suppressor of intact MSX-2 but also raise the possibility that MSX-2 gene may be an important downstream target for the Ras signaling pathways.

  15. Pulse processing in optical fibers using the temporal Radon-Wigner transform

    Energy Technology Data Exchange (ETDEWEB)

    Bulus-Rossini, L A; Costanzo-Caso, P A; Duchowicz, R [Centro de Investigaciones Opticas, CONICET La Plata - CIC, Camino Parque Centenario y 506, C.C. 3 (1897) La Plata (Argentina); Sicre, E E, E-mail: lbulus@ing.unlp.edu.ar [Instituto de Tecnologia, Facultad de Ingenieria y Ciencias Exactas, Universidad Argentina de la Empresa, Lima 717, C1073AAO Buenos Aires (Argentina)

    2011-01-01

    It is presented the use of the temporal Radon-Wigner transform (RWT), which is the squared modulus of the fractional Fourier transform (FRT) for a varying fractional order p, as a processing tool for pulses with FWHM of ps-tens of ps. For analysis purposes, the complete numerical generation of the RWT with 0 < p < 1 is proposed to select a particular pulse shape related to a determined value of p. To this end, the amplitude and phase of the signal to be processed are obtained using a pulse characterization technique. To synthesize the processed pulse, the selected FRT irradiance is optically produced employing a photonic device that combines phase modulation and dispersive transmission. The practical implementation of this device involves a scaling factor that depends on the modulation and dispersive parameters. It is explored the variation of this factor in order to obtain an enhancement of the particular characteristic sought in the pulse to be synthesized. To illustrate the implementation of the proposed method, numerical simulations of its application to compress signals commonly found in fiber optic transmission systems, are performed. The examples presented consider chirped Gaussian pulses and pulses distorted by group velocity dispersion and self-phase modulation.

  16. Public Information Programmes on Risks Due to Radon. Annex V

    International Nuclear Information System (INIS)

    2015-01-01

    Public concern about radon is generally lower than public concern about other comparable risks, or about much lower risks such as those associated with artificial radiation. The public tends to be most concerned about hazards that are: (a) Human made rather than natural; (b) Imposed by a human agency rather than arising by chance; (c) Able to cause harm to groups rather than individuals; (d) Obvious, immediate and ‘dread’ rather than covert, delayed and familiar. None of the four above mentioned factors that would increase concern apply to radon, and a study has found that householders often deny that a health risk exists. For this reason, public information programmes are necessary for the risks due to radon to be taken seriously

  17. 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.

  18. Cone-beam local reconstruction based on a Radon inversion transformation

    International Nuclear Information System (INIS)

    Wang Xian-Chao; Yan Bin; Li Lei; Hu Guo-En

    2012-01-01

    The local reconstruction from truncated projection data is one area of interest in image reconstruction for computed tomography (CT), which creates the possibility for dose reduction. In this paper, a filtered-backprojection (FBP) algorithm based on the Radon inversion transform is presented to deal with the three-dimensional (3D) local reconstruction in the circular geometry. The algorithm achieves the data filtering in two steps. The first step is the derivative of projections, which acts locally on the data and can thus be carried out accurately even in the presence of data truncation. The second step is the nonlocal Hilbert filtering. The numerical simulations and the real data reconstructions have been conducted to validate the new reconstruction algorithm. Compared with the approximate truncation resistant algorithm for computed tomography (ATRACT), not only it has a comparable ability to restrain truncation artifacts, but also its reconstruction efficiency is improved. It is about twice as fast as that of the ATRACT. Therefore, this work provides a simple and efficient approach for the approximate reconstruction from truncated projections in the circular cone-beam CT

  19. Indoor exposure to radon and its health effects

    International Nuclear Information System (INIS)

    Loskiewicz, J.

    1997-10-01

    Radon (Rn-222) is a noble radioactive gas which originates during U-238 series decay. As a noble gas it is not reacting with soils and building materials and therefore is showing large mobility due to its half-life of 3.82 days. It decays through alpha emission and is producing other radioactive isotopes (Po-218, Bi-214 etc.) which are solid. The migration of radon and its decay products can be in unattached form or attached to aerosols. The size of aerosol particles is important for adhesion coefficient value and for inhalation probability by human respiratory system. The unattached radon is penetrating more easily into lung space and there it may decay into radioactive and alpha emitting solid isotopes. The emitted alpha particle can damage sensitive cells. An alpha particle that penetrates that epithelial cells can deposit enough energy in a cell to kill or transform it. The transformed cell, alone or through interaction with some other agent, has the potential to develop eventually into a lung cancer. The data on risk of a lung cancer occurrence for high and medium concentrations of radon in the air will also be presented. (author)

  20. Radon anomalies along faults in North of Jordan

    International Nuclear Information System (INIS)

    Al-Tamimi, M.H.; Abumurad, K.M.

    2001-01-01

    Radon emanation was sampled in five locations in a limestone quarry area using SSNTDs CR-39. Radon levels in the soil air at four different well-known traceable fault planes were measured along a traverse line perpendicular to each of these faults. Radon levels at the fault were higher by a factor of 3-10 than away from the faults. However, some sites have broader shoulders than the others. The method was applied along a fifth inferred fault zone. The results show anomalous radon level in the sampled station near the fault zone, which gave a radon value higher by three times than background. This study draws its importance from the fact that in Jordan many cities and villages have been established over an intensive faulted land. Also, our study has considerable implications for the future radon mapping. Moreover, radon gas is proved to be a good tool for fault zones detection

  1. United role of radon decay products and nano-aerosols in radon dosimetry

    Science.gov (United States)

    Smerajec, M.; Vaupotič, J.

    2012-04-01

    The major part of human exposure to natural radiation originates from inhalation of radon (Rn) and radon short-lived decay products (RnDP: 218Po, 214Pb, 214Bi and 214Po). RnDP are formed as a result of α-transformation of radon. In the beginning they are positive ions which neutralize and form clusters with air molecules, and later partly attach to background aerosol particles in indoor air. Eventually, they appear as radioactive nano-aerosols with a bimodal size distribution in ranges of 1-10 nm (unattached RnDP) and of 200-800 nm (attached RnDP). When inhaled, they are deposited in the respiratory tract. Deposition is more efficient for smaller particles. Therefore, the fraction (fun) of the unattached RnDP, which appears to be influenced by the number concentration and size distribution of general (background) aerosols in the ambient air, has a crucial role in radon dosimetry. Radon, radon decay products and general aerosols have been monitored simultaneously in the kitchen of a typical rural house under real living conditions, also comprising four human activities generating particular matter: cooking and baking, as two typical activities in kitchen, and cigarette smoking and candle burning. In periods without any human activity, the total number concentration of general aerosol ranged from 1000 to 3000 cm-3,with the geometric mean of particle diameter in the range of 60-68 nm and with 0.1-1 % of particles smaller than 10 nm. Preparation of coffee changed the concentration to 193,000 cm-3, the geometric mean of diameter to 20 nm and fraction of particles smaller than 10 nm to 11 %. The respective changes were for baking cake: 503,000 cm-3, 17 nm and 19 %, for smoking:423,000 cm-3, 83 nm and 0.4 %, and forcandle burning: 945,000 cm-3, 8 nm and 85 %. While, as expected, a reduction of fun was observed during cooking, baking and smoking, when larger particles were emitted, fun did not increase during candle burning with mostly particles smaller than 10 nm

  2. Dual-Frequency Impedance Transformer Using Coupled-Line For Ultra-High Transforming Ratio

    Directory of Open Access Journals (Sweden)

    R. K. Barik

    2017-12-01

    Full Text Available In this paper, a new type of dual-frequency impedance transformer is presented for ultra-high transforming ratio. The proposed configuration consists of parallel coupled-line, series transmission lines and short-ended stubs. The even and odd-mode analysis is applied to obtain the design equations and hence to provide an accurate solution. Three examples of the dual-frequency transformer with load impedance of 500, 1000 and 1500 Ω are designed to study the matching capability and bandwidth property. To prove the frequency agility of the proposed network, three prototypes of dual-frequency impedance transformer with transforming ratio of 10, 20 and 30 are fabricated and tested. The measured return loss is greater than 15 dB at two operating frequencies for all the prototypes. Also, the bandwidth is more than 60 MHz at each frequency band for all the prototypes. The measured return loss is found in good agreement with the circuit and full-wave simulations.

  3. Attempt to determine radon entry rate and air exchange rate variable in time from the time course of indoor radon concentration

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J [State Office for Nuclear Protection, Prague (Czech Republic)

    1996-12-31

    For radon diagnosis in houses the `ventilation experiment` was used as a standard method. After removal of indoor radon by draught the build-up of radon concentration a(t) [Bq/m{sup 3}] was measured continuously and from the time course the constant radon entry rate A [Bq/h] and the exchange rate k [h{sup -1}] was calculated by regression analysis using model relation a(t) A(1-e{sup -kt})/kV with V [m{sup 3}] for volume of the room. The conditions have to be stable for several hours so that the assumption of constant A and k was justified. During the day both quantities were independently (?) changing, therefore a method to determine variable entry rate A(t) and exchange rate k(t) is needed for a better understanding of the variability of the indoor radon concentration. Two approaches are given for the determination of variable in time radon entry rates and air exchange rates from continuously measured indoor radon concentration - numerical solution of the equivalent difference equations in deterministic or statistic form. The approaches are not always successful. Failures giving a right ration for the searched rates but not of the rates them self could not be explained.

  4. Large-scale radon hazard evaluation in the Oslofjord region of Norway utilizing indoor radon concentrations, airborne gamma ray spectrometry and geological mapping

    International Nuclear Information System (INIS)

    Smethurst, Mark Andrew; Strand, Terje; Sundal, Aud Venke; Rudjord, Anne Liv

    2008-01-01

    We test whether airborne gamma ray spectrometer measurements can be used to estimate levels of radon hazard in the Oslofjord region of Norway. We compile 43,000 line kilometres of gamma ray spectrometer data from 8 airborne surveys covering 10,000 km 2 and compare them with 6326 indoor radon measurements. We find a clear spatial correlation between areas with elevated concentrations of uranium daughters in the near surface of the ground and regions with high incidence of elevated radon concentrations in dwellings. This correlation permits cautious use of the airborne data in radon hazard evaluation where direct measurements of indoor radon concentrations are few or absent. In radon hazard evaluation there is a natural synergy between the mapping of radon in indoor air, bedrock and drift geology mapping and airborne gamma ray surveying. We produce radon hazard forecast maps for the Oslofjord region based on a spatial union of hazard indicators from all four of these data sources. Indication of elevated radon hazard in any one of the data sets leads to the classification of a region as having an elevated radon hazard potential. This approach is inclusive in nature and we find that the majority of actual radon hazards lie in the assumed elevated risk regions

  5. Radon in your dwellings - problems and mitigation

    International Nuclear Information System (INIS)

    Srivastava, D.S.

    2011-01-01

    The problem of radon in dwellings gained importance in 1984 after the Stanely Watra's house incidence in Pennsylvania USA. Since then several radon measuring techniques have been identified and instrumentations developed. National survey programs were started for monitoring radon levels in dwellings by Government authorities in all developed and developing countries including India. Successively, the measurement of thoron levels was also found desirable especially in high radiation background areas. A lot of work has been done since then by scientists and university researches and thousands of publications have been made in this field. Several developed countries have given guide lines for initiating action to reduce radon levels in dwellings if it is beyond 200-400 Bq/m 2 . The recommended 'action level' is found to depend upon the authorities making the recommendations. This talk is aimed to produce public awareness about the health hazard posed by concentration of naturally occurring radon gas in our dwellings, the sources of its production and mitigation of radon problem. The matter will be discussed in a general way using ppt presentation. (author)

  6. 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

  7. Behavior of radon and its decay products in physical media

    International Nuclear Information System (INIS)

    Chavez B, A.

    1990-06-01

    This study was carried out to know the radon behavior, it shows some of its decay products of short life, the same as the equations that describe the growth of the activity of each decay product in a source that initially is radon. The study threw results that they are applicable in geology, uranium prospecting, as well as in radiological safety. The use of membranes to filter the decay products of radon and the use of these for protection of the detector, it has opened a new line in the study of the radon. (Author)

  8. 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

  9. High-voltage isolation transformer for sub-nanosecond rise time pulses constructed with annular parallel-strip transmission lines.

    Science.gov (United States)

    Homma, Akira

    2011-07-01

    A novel annular parallel-strip transmission line was devised to construct high-voltage high-speed pulse isolation transformers. The transmission lines can easily realize stable high-voltage operation and good impedance matching between primary and secondary circuits. The time constant for the step response of the transformer was calculated by introducing a simple low-frequency equivalent circuit model. Results show that the relation between the time constant and low-cut-off frequency of the transformer conforms to the theory of the general first-order linear time-invariant system. Results also show that the test transformer composed of the new transmission lines can transmit about 600 ps rise time pulses across the dc potential difference of more than 150 kV with insertion loss of -2.5 dB. The measured effective time constant of 12 ns agreed exactly with the theoretically predicted value. For practical applications involving the delivery of synchronized trigger signals to a dc high-voltage electron gun station, the transformer described in this paper exhibited advantages over methods using fiber optic cables for the signal transfer system. This transformer has no jitter or breakdown problems that invariably occur in active circuit components.

  10. Least-squares reverse time migration with local Radon-based preconditioning

    KAUST Repository

    Dutta, Gaurav

    2017-03-08

    Least-squares migration (LSM) can produce images with better balanced amplitudes and fewer artifacts than standard migration. The conventional objective function used for LSM minimizes the L2-norm of the data residual between the predicted and the observed data. However, for field-data applications in which the recorded data are noisy and undersampled, the conventional formulation of LSM fails to provide the desired uplift in the quality of the inverted image. We have developed a leastsquares reverse time migration (LSRTM) method using local Radon-based preconditioning to overcome the low signal-tonoise ratio (S/N) problem of noisy or severely undersampled data. A high-resolution local Radon transform of the reflectivity is used, and sparseness constraints are imposed on the inverted reflectivity in the local Radon domain. The sparseness constraint is that the inverted reflectivity is sparse in the Radon domain and each location of the subsurface is represented by a limited number of geologic dips. The forward and the inverse mapping of the reflectivity to the local Radon domain and vice versa is done through 3D Fourier-based discrete Radon transform operators. The weights for the preconditioning are chosen to be varying locally based on the relative amplitudes of the local dips or assigned using quantile measures. Numerical tests on synthetic and field data validate the effectiveness of our approach in producing images with good S/N and fewer aliasing artifacts when compared with standard RTM or standard LSRTM.

  11. Transformation lines in an Fe-Cr-Ni-Mn-Si polycrystalline shape memory alloy

    International Nuclear Information System (INIS)

    Tanaka, Kikuaki; Hayashi, Toshimitsu; Fischer, F.D.; Buchmayr, B.

    1994-01-01

    Transformation lines, the martensite/austenite start and finish conditions in the stress-temperature plane, are determined in an Fe-Cr-Ni-Mn-Si polycrystalline shape memory alloy with two different experimental procedures. The transformation lines are shown to be almost linear with nearly the same slope. The martensitic transformation zone and the reverse transformation zone do not coincide, and the reverse transformation zone is very wide; T Af -T As ∼ 180 K. The strong dependence on the preloading of the transformation lines, especially of the reverse transformation lines, is examined. (orig.)

  12. Development and testing of the detector for monitoring radon double-filter method

    International Nuclear Information System (INIS)

    Sevcik, P.

    2008-01-01

    Applications of physics in the study of radon transport processes in the atmosphere and of testing of atmospheric transport models require sensitive detection devices with low maintenance requirements. The most precise devices involved in the worldwide monitoring program of the atmosphere (GAW) determine volume activity of radon from a variety of daughter products of 222 Rn, resulting in a working volume of the detector (double-filter method). The purpose of this work was to explore theoretically and experimentally the possibilities and limits of a particular simple implementation of this procedure. Tested apparatus consists of a 200 dm 3 chamber (metal drum), where are developed transformation products of radon and semiconductor detector with surface barrier, which registers α particles from the conversion of daughter products 222 Rn collected on a filter at the outlet of the chamber. Testing of the apparatus takes place in the atmosphere with higher concentrations of radon. The measured variations of volume activities 222 Rn have the same character as the variations of radon concentration in the air in laboratory. Minimum detectable activity at 95% significance level is 16.0 Bq.m -3 at a pumping speed of the air 20 dm 3 .min - 1 and 13.0 Bq.m -3 at a pumping rate 24 dm 3 .min -1 . These values are still too high for using the apparatus for measuring in external atmosphere. The main limit of the apparatus is a capture of transformation products arising on the inner walls of the chamber (plate-out effect). The effectiveness of collecting 218 Po from the chamber on the filter in our measurements was only 2.8%. But we managed to increase it to about 20% by adding aerosol delivery systems into production chamber of transformation products of radon. It turns out that based on this principle can be made sensitive and continuously working monitor of radon. (author)

  13. 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.

  14. Effect of number of of projections on inverse radon transform based image reconstruction by using filtered back-projection for parallel beam transmission tomography

    International Nuclear Information System (INIS)

    Qureshi, S.A.; Mirza, S.M.; Arif, M.

    2007-01-01

    This paper present the effect of number of projections on inverse Radon transform (IRT) estimation using filtered back-projection (FBP) technique for parallel beam transmission tomography. The head phantom and the lung phantom have been used in this work. Various filters used in this study include Ram-Lak, Shepp-Logan, Cosin, Hamming and Hanning filters. The slices have been reconstructed by increasing the number of projections through parallel beam transmission tomography keeping the projections uniformly distributed. The Euclidean and Mean Squared errors and peak signal-to-noise ratio (PSNR) have been analyzed for their sensitiveness as functions of number of projections. It has found that image quality improves with the number of projections but at the cost of the computer time. The error has been minimized to get the best approximation of inverse Radon transform (IRT) as the number of projections is enhanced. The value of PSNR has been found to increase from 8.20 to 24.53 dB as the number of projections is raised from 5 to 180 for head phantom. (author)

  15. Soil radon levels across the Amer fault

    International Nuclear Information System (INIS)

    Font, Ll.; Baixeras, C.; Moreno, V.; Bach, J.

    2008-01-01

    Soil radon levels have been measured across the Amer fault, which is located near the volcanic region of La Garrotxa, Spain. Both passive (LR-115, time-integrating) and active (Clipperton II, time-resolved) detectors have been used in a survey in which 27 measurement points were selected in five lines perpendicular to the Amer fault in the village area of Amer. The averaged results show an influence of the distance to the fault on the mean soil radon values. The dynamic results show a very clear seasonal effect on the soil radon levels. The results obtained support the hypothesis that the fault is still active

  16. Energy deposition and radiation quality of radon and radon daughters. Final report

    International Nuclear Information System (INIS)

    Karam, L.R.; Caswell, R.S.

    1996-01-01

    This program was aimed at creating a quantitative physical description, at the micrometer and nanometer levels, of the physical interactions of the alpha particles from radon and its daughters with cells at risk in the bronchial epithelium. The authors calculated alpha-particle energy spectra incident upon the cells and also energy deposition spectra in micrometer- and nanometer-sized sites as a function of cell depth, site size, airway diameter, activities of 218 Po and 214 Po, and other parameters. These data are now being applied, using biophysical models of radiation effects, to predict cell killing, mutations, and cell transformation. The model predictions are then compared to experimental biophysical, biochemical, and biological information. These studies contribute to a detailed understanding of the mechanisms of the biological effectiveness of the radiations emitted by radon and its progeny

  17. Anomalous radon emanation linked to preseismic electromagnetic phenomena

    Directory of Open Access Journals (Sweden)

    Y. Omori

    2007-10-01

    Full Text Available Anomalous emanation of radon (222Rn was observed preceding large earthquakes and is considered to be linked to preseismic electromagnetic phenomena (e.g. great changes of atmospheric electric field and ionospheric disturbances. Here we analyze atmospheric radon concentration and estimate changes of electrical conditions in atmosphere due to preseismic radon anomaly. The increase of radon emanation obeys crustal damage evolution, following a power-law of time-to-earthquake. Moreover, the radon emanation decreases the atmospheric electric field by 40%, besides influencing the maximum strength of atmospheric electric field by 104–105 V/m enough to trigger ionospheric disturbances. These changes are within the ranges observed or explaining electromagnetic phenomena associated with large earthquakes.

  18. Mapping of groundwater radon potential

    International Nuclear Information System (INIS)

    Aekerblom, G.; Lindgren, J.

    1997-01-01

    The domestic use of water with elevated radon concentration may represent a public health hazard, partly due to the release of radon to the indoor air. While only a limited number of countries have implemented regulations with respect to radon in water, many more are considering doing so. The compulsory limits proposed by Swedish authorities are 100 Bq/1 for public water, while water from private wells is not to exceed 1000 Bq/1. Furthermore, it is recommended that water with a radon content above 500 Bq/1 should not be given to children under five years of age. In Sweden, the estimated number of wells with radon levels above 1000 Bq/1 exceeds 10,000, with a considerable amount in excess of 10,000 Bq/1. The highest radon concentration in a well supplying drinking water encountered so far is 57,000 Bq/1. Radon levels exceeding 500 Bq/1 are almost exclusively found in wells drilled into bedrock and in springs with intramontaneous water. Elevated ground water radon levels require that the water has passed through bedrock with elevated concentration of uranium, or through fractures with coatings of minerals containing enhanced concentrations of radium-226. Intramontaneous water from areas with uranium-bearing rock types (e.g. uranium-rich granites, pegmatites and vulcanites) often manifests elevated radon levels. Routines for the establishment of risk maps focusing on water are currently under development. The backbone of the process is the access to high spatial resolution radiometric information together with bedrock and soil information on a detailed scale (1:50,000). This information is available from the Geological Survey of Sweden, which is routinely carrying out airborne measurements at an altitude of 30 m and a line spacing of 200 m. While some 60% of Sweden is covered up to now, 75 % is expected to be covered within the next ten years. Other available databases utilized in the risk mapping process include radon measurements in wells, geochemical data from

  19. Radon measurement in Malaysia water samples

    International Nuclear Information System (INIS)

    Ibrahim, A.B.; Rosli Mahat; Yusof Md Amin

    1995-01-01

    This paper reported the results of the measurement of radon in local water. The water samples collected were rainwater, river water, seawater, well water or ground water at area of State of Selangor and Kuala Lumpur. The samples were collected in scintillation cell ZnS(Ag) through Radon Degassing Unit RDU 200. Alpha activity was counted with scintillation counters RD 200 at energy 5.5 MeV. (author)

  20. Transmission line transformer for reliable and low-jitter triggering of a railgap switch.

    Science.gov (United States)

    Verma, Rishi; Mishra, Ekansh; Sagar, Karuna; Meena, Manraj; Shyam, Anurag

    2014-09-01

    The performance of railgap switch critically relies upon multichannel breakdown between the extended electrodes (rails) in order to ensure distributed current transfer along electrode length and to minimize the switch inductance. The initiation of several simultaneous arc channels along the switch length depends on the gap triggering technique and on the rate at which the electric field changes within the gap. This paper presents design, construction, and output characteristics of a coaxial cable based three-stage transmission line transformer (TLT) that is capable of initiating multichannel breakdown in a high voltage, low inductance railgap switch. In each stage three identical lengths of URM67 coaxial cables have been used in parallel and they have been wounded in separate cassettes to enhance the isolation of the output of transformer from the input. The cascaded output impedance of TLT is ~50 Ω. Along with multi-channel formation over the complete length of electrode rails, significant reduction in jitter (≤2 ns) and conduction delay (≤60 ns) has been observed by the realization of large amplitude (~80 kV), high dV/dt (~6 kV/ns) pulse produced by the indigenously developed TLT based trigger generator. The superior performance of TLT over conventional pulse transformer for railgap triggering application has been compared and demonstrated experimentally.

  1. 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 ...

  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. Etched track radiometers in radon measurements: a review

    CERN Document Server

    Nikolaev, V A

    1999-01-01

    Passive radon radiometers, based on alpha particle etched track detectors, are very attractive for the assessment of radon exposure. The present review considers various devices used for measurement of the volume activity of radon isotopes and their daughters and determination of equilibrium coefficients. Such devices can be classified into 8 groups: (i) open or 'bare' detectors, (ii) open chambers, (iii) sup 2 sup 2 sup 2 Rn chambers with an inlet filter, (iv) advanced sup 2 sup 2 sup 2 Rn radiometers, (v) multipurpose radiometers, (vi) radiometers based on a combination of etched track detectors and an electrostatic field, (vii) radiometers based on etched track detectors and activated charcoal and (viii) devices for the measurement of radon isotopes and/or radon daughters by means of track parameter measurements. Some of them such as the open detector and the chamber with an inlet filter have a variety of modifications and are applied widely both in geophysical research and radon dosimetric surveys. At the...

  4. Radon dynamics in underwater thermal radon therapy

    International Nuclear Information System (INIS)

    Lettner, H.; Hofmann, W.; Winkler, R.; Rolle, R.; Foisner, W.

    1998-01-01

    At a facility for underwater thermal radon therapy in Bad Hofgastein, experiments were carried out with the aim of establishing radon in the air exhaled by the treated patients and of radon decay products on the skin of the patients. The time course of radon concentration in the exhaled air shows a maximum a few minutes after entering the bath, then the Rn concentration remains constant over the remaining time spent in the bath. Taking into account several simplifying assumptions, the average dose to the epidermis from radon daughters is about 50 μGy. (A.K.)

  5. 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 - ...

  6. Experimental study of radon and thoron diffusion through barriers

    Energy Technology Data Exchange (ETDEWEB)

    Durcik, M; Havlik, F [Inst. of Preventive and Clinical Medicine, 83301 Bratislava (Slovakia)

    1996-12-31

    The measurement results of diffusion parameters for radon (radon-222) and thoron (radon-220) through barriers, experimental equipment and theoretical background of diffusion are presented in this paper. The diffusion barriers are used for measuring radon and thoron by passive detectors in order to test the reduction techniques in houses. Six samples (filter paper, rubber, polyethylene, glass laminate, polypropylene) were studied for radon diffusion. The thickness barriers were from 0.012 mm to 2 mm, the diffusion area was 16 cm{sup 2} and the volume V{sub 2} was 30 dm{sup 3}. The diffusion constants D were obtained using given expressions and the data from measurements. The procedures used in experiments are useful for study of diffusion ability of radon and thoron in barriers and determination diffusion parameters from short term measurements. (J.K.). 2 figs., 1 tab., 3 refs.

  7. Experimental study of radon and thoron diffusion through barriers

    International Nuclear Information System (INIS)

    Durcik, M.; Havlik, F.

    1995-01-01

    The measurement results of diffusion parameters for radon (radon-222) and thoron (radon-220) through barriers, experimental equipment and theoretical background of diffusion are presented in this paper. The diffusion barriers are used for measuring radon and thoron by passive detectors in order to test the reduction techniques in houses. Six samples (filter paper, rubber, polyethylene, glass laminate, polypropylene) were studied for radon diffusion. The thickness barriers were from 0.012 mm to 2 mm, the diffusion area was 16 cm 2 and the volume V 2 was 30 dm 3 . The diffusion constants D were obtained using given expressions and the data from measurements. The procedures used in experiments are useful for study of diffusion ability of radon and thoron in barriers and determination diffusion parameters from short term measurements. (J.K.). 2 figs., 1 tab., 3 refs

  8. Radon-technical design methods based on radon classification of the soil

    International Nuclear Information System (INIS)

    Kettunen, A.V.

    1993-01-01

    Radon-technical classification of the foundation soil divides the foundation soil into four classes: negligible, normal, high and very high. Separate radon-technical designing methods and radon-technical solutions have been developed for each class. On regions of negligible class, no specific radon-technical designing methods are needed. On regions of normal radon class, there is no need for actual radon-technical designing based on calculations, whereas existing radon-technical solutions can be used. On regions of high and very high radon class, a separate radon-technical designing should be performed in each case, where radon-technical solutions are designed so that expected value for indoor radon content is lower than the maximum allowable radon content. (orig.). (3 refs., 2 figs., 2 tabs.)

  9. Technical Area V (TA-V) transformation project close-out report.

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    Sandia National Laboratories (SNL) Technical Area V (TA-V) has provided unique nuclear experimental environments for decades. The technologies tested in TA-V facilities have furthered the United States Nuclear Weapons program and has contributed to the national energy and homeland security mission. The importance of TA-V working efficiently to produce an attractive and effective platform for experiments should not be underestimated. Throughout its brief history, TA-V has evolved to address multiple and diverse sets of requirements. These requirements evolved over many years; however, the requirements had not been managed nor communicated comprehensively or effectively. A series of programmatic findings over several years of external audits was evidence of this downfall. Today, these same requirements flow down through a new TA-V management system that produces consistently applied and reproducible approaches to work practices. In 2008, the TA-V department managers assessed the state of TA-V services and work activities to understand how to improve customer interfaces, stakeholders perceptions, and workforce efficiencies. The TA-V management team initiated the TA-V Transformation Project after they deemed the pre-June 2008 operational model to be ineffective in managing work and in providing integrated, continuous improvement to TA-V processes. This report summarizes the TA-V Transformation Project goals, activities, and accomplishments.

  10. Radon in houses due to radon in potable water

    International Nuclear Information System (INIS)

    Hess, C.T.; Korsah, J.K.; Einloth, C.J.

    1987-01-01

    Radon concentration in the air of 10 houses has been measured as a function of water use and meterological parameters such as barometric pressure, wind velocity and direction, indoor and outdoor temperature, and rainfall. Results of calibrations and data collected in winter, spring, fall, and summer are given for selected houses. Average values of radon concentration in air are from 0.80 to 77 rhoCi/1. Water use average ranges from 70 to 240 gal/day. Average potential alpha energy concentrations in these houses range from 0.02 to 1.6 working levels. The radon level due to water use ranges from 0 to 36% of the house radon from soil and water combined. The radon level change due to use of a filter on the water supply shows a 60% reduction in radon in the house. Conclusions are that water radon can be a major fraction of the radon in houses. The ratio of airborne radon concentration due to water use to the radon concentration in water is 4.5 x 10/sup -5/ - 13 x 10/sup -5/

  11. Broadband Impedance Transformer Based on Asymmetric Coupled Transmission Lines in Nonhomogeneous Medium

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Krozer, Viktor; Meincke, Peter

    2007-01-01

    A new broadband quarter-wavelength impedance transformer based on an asymmetric coupled line section is presented. The bandwidth of the coupled line transformer is extended with the help of an interconnecting transmission line. An analytical model for the transformer is developed. The analysis...... of the structure reveals that a fractional bandwidth of more than 100% at –20 dB reflection level can be achieved with such a structure. An experimental transformer circuit has been designed, fabricated and tested. Theoretical and experimental results are fair agreement and confirm the established theory...

  12. Contribution of radon and radon daughters to respiratory cancer

    International Nuclear Information System (INIS)

    Harley, N.; Samet, J.M.; Cross, F.T.; Hess, T.; Muller, J.; Thomas, D.

    1986-01-01

    This article reviews studies on the contribution of radon and radon daughters to respiratory cancer and proposes recommendations for further research, particularly a national radon survey. The steady-state outdoor radon concentration averages 200 pCi/m3, and indoor levels are about 4 times higher. The primary source of radon in homes is the underlying soil; entry depends on multiple variables and reduced ventilation for energy conservation increases indoor radon levels. Occupational exposures are expressed in units of radon daughter potential energy concentration or working level (WL). Cumulative exposure is the product of the working level and the time exposed. The unit for cumulative exposure is the working level month (WLM). The occupational standard for radon exposure is 4 WLM/year, and 2 WLM/year has been suggested as a guideline for remedial action in homes. Epidemiologic studies show that miners with cumulative radon daughter exposures somewhat below 100 WLM have excess lung cancer mortality. Some 3% to 8% of miners studied have developed lung cancer attributable to radon daughters. All of the underground mining studies show an increased risk of lung cancer with radon daughter exposure. All cell types of lung cancer increased with radon exposure. If radon and smoking act in a multiplicative manner, then the risk for smokers could be 10 times that for nonsmokers. The potential risk of lung cancer appears to be between 1 and 2 per 10,000/WLM, which yields a significant number of lung cancers as some 220 million persons in the United States are exposed on average to 10 to 20 WLM/lifetime

  13. Transformational III-V Electronics

    KAUST Repository

    Nour, Maha A.

    2014-04-01

    Flexible electronics using III-V materials for nano-electronics with high electron mobility and optoelectronics with direct band gap are attractive for many applications. This thesis describes a complementary metal oxide semiconductor (CMOS) compatible process for transforming traditional III-V materials based electronics into flexible one. The thesis reports releasing 200 nm of Gallium Arsenide (GaAs) from 200 nm GaAs / 300 nm Aluminum Arsenide (AlAs) stack on GaAs substrate using diluted hydrofluoric acid (HF). This process enables releasing a single top layer compared to peeling off all layers with small sizes at the same time. This is done utilizing a network of release holes that contributes to the better transparency (45 % at 724 nm wavelengths) observed. Fabrication of metal oxide semiconductor capacitor (MOSCAPs) on GaAs is followed by releasing it to have devices on flexible 200 nm GaAs. Similarly, flexible GaSb and InP fabrication process is also reported to transform traditional electronics into large-area flexible electronics.

  14. Indoor radon pollution: update. Bibliographic series

    International Nuclear Information System (INIS)

    Richard, S.A.

    1988-12-01

    This bibliography focuses on indoor radon pollution problems and is organized according to the following major topic areas: I-Overview (covering general areas such as law and policy, popular press, communication and education, indoor air and books); II-Health Effects (epidemiology, risk estimates, and dosimetry); III-Exposure (house construction, geology, source, physical properties, and radon in water); IV-Surveys (national and international case studies); V-Mitigation; and VI-Measurement Techniques. Section VIII-Appendix, lists State Contacts

  15. 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

  16. 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)

  17. Coupled Transmission Lines as Impedance Transformer

    DEFF Research Database (Denmark)

    Jensen, Thomas; Zhurbenko, Vitaliy; Krozer, Viktor

    2007-01-01

    A theoretical investigation of the use of a coupled line section as an impedance transformer is presented. We show how to properly select the terminations of the coupled line structures for effective matching of real and complex loads in both narrow and wide frequency ranges. The corresponding...... circuit configurations and the design procedures are proposed. Synthesis relations are derived and provided for efficient matching circuit construction. Design examples are given to demonstrate the flexibility and limitations of the design methods and to show their validity for practical applications...

  18. Adsorption of radon and water vapor on commercial activated carbons

    International Nuclear Information System (INIS)

    Hassan, N.M.; Ghosh, T.K.; Hines, A.L.; Loyalka, S.K.

    1995-01-01

    Equilibrium adsorption isotherms are reported for radon and water vapor on two commercial activated carbons: coconut shell Type PCB and hardwood Type BD. The isotherms of the water vapor were measured gravimetrically at 298 K. The isotherms of radon from dry nitrogen were obtained at 293, 298, and 308 K while the data for the mixture of radon and water vapor were measured at 298 K. The concentrations of radon in the gas and solid phases were measured simultaneously, once the adsorption equilibrium and the radioactive equilibrium between the radon and its daughter products were established. The shape of the isotherms was of Type III for the radon and Type V for the water vapor, according to Brunauer's classification. The adsorption mechanism was similar for both the radon and the water vapor, being physical adsorption on the macropore surface area in the low pressure region and micropore filling near saturation pressure. The uptake capacity of radon decreased both with increasing temperature and relative humidity. The heat of adsorption data indicated that the PCB- and the BD-activated carbons provided a heterogeneous surface for radon adsorption. The equilibrium data for radon were correlated with a modified Freundlich equation

  19. 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

  20. 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

  1. A study of Radon-Concentration Distribution in Buildings in Gyeong-ju

    Energy Technology Data Exchange (ETDEWEB)

    Park, C. H.; Jang, S. Y.; Jung, O. J.; Moon, J. H. [Dongguk University, Gyeongju (Korea, Republic of)

    2010-10-15

    Radon({sup 222}Rn) gas is the natural radiation generated by radioactive decay of uranium({sup 238}U) nuclide. The radon which exists in ground flows into the inside by the atmospheric temperature, the differential-pressure or a gap of building underground and a ejection by a drywall with a phosphoric In Korea, Korean Institute of Nuclear Safety had been studied about the inside-radon radioactivity investigation over the nation. In the area around the nuclear power plant, it is possible to exist both of a radioactivity nuclide and a natural. Therefore it is necessary to investigate the radon radioactivity in surrounding area of nuclear power plants. In this study, it is purpose to develop the method of establishing the on-line monitoring system to minimize the radiological effect due to radon gas, based on the real state of radon exposure in Gyeong-ju surrounding Nuclear Power Plant

  2. Seismic data two-step recovery approach combining sparsity-promoting and hyperbolic Radon transform methods

    International Nuclear Information System (INIS)

    Wang, Hanchuang; Chen, Shengchang; Ren, Haoran; Liang, Donghui; Zhou, Huamin; She, Deping

    2015-01-01

    In current research of seismic data recovery problems, the sparsity-promoting method usually produces an insufficient recovery result at the locations of null traces. The HRT (hyperbolic Radon transform) method can be applied to problems of seismic data recovery with approximately hyperbolic events. Influenced by deviations of hyperbolic characteristics between real and ideal travel-time curves, some spurious events are usually introduced and the recovery effect of intermediate and far-offset traces is worse than that of near-offset traces. Sparsity-promoting recovery is primarily dependent on the sparsity of seismic data in the sparse transform domain (i.e. on the local waveform characteristics), whereas HRT recovery is severely affected by the global characteristics of the seismic events. Inspired by the above conclusion, a two-step recovery approach combining sparsity-promoting and time-invariant HRT methods is proposed, which is based on both local and global characteristics of the seismic data. Two implementation strategies are presented in detail, and the selection criteria of the relevant strategies is also discussed. Numerical examples of synthetic and real data verify that the new approach can achieve a better recovery effect by simultaneously overcoming the shortcomings of sparsity-promoting recovery and HRT recovery. (paper)

  3. 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.

  4. Distance to high-voltage power lines and risk of childhood leukemia--an analysis of confounding by and interaction with other potential risk factors.

    Directory of Open Access Journals (Sweden)

    Camilla Pedersen

    Full Text Available We investigated whether there is an interaction between distance from residence at birth to nearest power line and domestic radon and traffic-related air pollution, respectively, in relation to childhood leukemia risk. Further, we investigated whether adjusting for potential confounders alters the association between distance to nearest power line and childhood leukemia. We included 1024 cases aged <15, diagnosed with leukemia during 1968-1991, from the Danish Cancer Registry and 2048 controls randomly selected from the Danish childhood population and individually matched by gender and year of birth. We used geographical information systems to determine the distance between residence at birth and the nearest 132-400 kV overhead power line. Concentrations of domestic radon and traffic-related air pollution (NOx at the front door were estimated using validated models. We found a statistically significant interaction between distance to nearest power line and domestic radon regarding risk of childhood leukemia (p = 0.01 when using the median radon level as cut-off point but not when using the 75th percentile (p = 0.90. We found no evidence of an interaction between distance to nearest power line and traffic-related air pollution (p = 0.73. We found almost no change in the estimated association between distance to power line and risk of childhood leukemia when adjusting for socioeconomic status of the municipality, urbanization, maternal age, birth order, domestic radon and traffic-related air pollution. The statistically significant interaction between distance to nearest power line and domestic radon was based on few exposed cases and controls and sensitive to the choice of exposure categorization and might, therefore, be due to chance.

  5. A reference aerosol for a radon reference chamber

    Science.gov (United States)

    Paul, Annette; Keyser, Uwe

    1996-02-01

    The measurement of radon and radon progenies and the calibration of their detection systems require the production and measurement of aerosols well-defined in size and concentration. In the German radon reference chamber, because of its unique chemical and physical properties, carnauba wax is used to produce standard aerosols. The aerosol size spectra are measured on-line by an aerosol measurement system in the range of 10 nm to 1 μm aerodynamic diameter. The experimental set-ups for the study of adsorption of radioactive ions on aerosols as function of their size and concentration will be described, the results presented and further adaptations for an aerosol jet introduced (for example, for the measurement of short-lived neutron-rich isotopes). Data on the dependence of aerosol radius, ion concentration and element selectivity is collected by using a 252Cf-sf source. The fission products of this source range widely in elements, isotopes and charges. Adsorption and the transport of radioactive ions on aerosols have therefore been studied for various ions for the first time, simultaneously with the aerosol size on-line spectrometry.

  6. A reference aerosol for a radon reference chamber

    Energy Technology Data Exchange (ETDEWEB)

    Paul, A. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Keyser, U. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    1996-01-11

    The measurement of radon and radon progenies and the calibration of their detection systems require the production and measurement of aerosols well-defined in size and concentration. In the German radon reference chamber, because of its unique chemical and physical properties, carnauba wax is used to produce standard aerosols. The aerosol size spectra are measured on-line by an aerosol measurement system in the range of 10 nm to 1 {mu}m aerodynamic diameter. The experimental set-ups for the study of adsorption of radioactive ions on aerosols as function of their size and concentration are described, the results presented and further adaptations for an aerosol jet introduced (for example, for the measurement of short-lived neutron-rich isotopes). Data on the dependence of aerosol radius, ion concentration and element selectivity is collected by using a {sup 252}Cf-sf source. The fission products of this source range widely in elements, isotopes and charges. Adsorption and the transport of radioactive ions on aerosols have therefore been studied for various ions for the first time, simultaneously with the aerosol size on-line spectrometry. (orig.).

  7. Observations on the spatio-temporal patterns of radon along the western fault of the Dead Sea Transform, NW Dead Sea

    International Nuclear Information System (INIS)

    Steinitz, G.; Piatibratova, O.; Malik, U.

    2015-01-01

    An extensive radon anomaly is developed along the western boundary fault of the Dead Sea Transform in the NW sector of the Dead Sea, extending 15-20 km north-south. The highest radon values occur in proximity to the fault scarp. Radon is measured, in gravel (depth 1.5-3 m) at sites located at a) on-fault positions, 1-30 meters east of the fault scarp, and b) off-fault positions located 600-800 the east. Prominent signals occur in the annual and daily periodicity bands, as well as non-periodic multi-day variations (2-20 days). Modulations occur among the annual variation and the multi-day and the daily signals, and between the multi-day and the daily signal. Dissimilar variation patterns occur at on-fault versus off-fault sites in the time domain, and in the relative amplitude of the daily periodicities. Variation patterns and their modulations are similar to those encountered in experimental simulations. It is concluded that: 1) above surface atmospheric influences can be excluded; 2) a remote above surface influence probably drives the periodic components in the annual and diurnal bands; 3) diurnal as well as the multi-day signals are modified and inter-modulated by near field geological (static) and geophysical (dynamic) influences. Systematically different influences are operating at on-fault versus off- fault positions, so far the natures of these near field influences are unidentified. (authors)

  8. Stratified random sampling plans designed to assist in the determination of radon and radon daughter concentrations in underground uranium mine atmosphere

    International Nuclear Information System (INIS)

    Makepeace, C.E.

    1981-01-01

    Sampling strategies for the monitoring of deleterious agents present in uranium mine air in underground and surface mining areas are described. These methods are designed to prevent overexposure of the lining of the respiratory system of uranium miners to ionizing radiation from radon and radon daughters, and whole body overexposure to external gamma radiation. A detailed description is provided of stratified random sampling monitoring methodology for obtaining baseline data to be used as a reference for subsequent compliance assessment

  9. Overview of current radon and radon daughter research at LBL

    International Nuclear Information System (INIS)

    1983-01-01

    This report provides a brief summary of radon and radon daughter research at Lawrence Berkeley Laboratory. The radon and radon daughter research program has two broad goals: (1) the study of sources of radon and its subsequent transport into houses, and (2) research on the behavior of radon daughters in indoor environments. Additional research effort is directed to several auxiliary areas, including development of instrumentation and monitoring techniques, studies of indoor air movement, and measurement and control of indoor particulate concentrations

  10. 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

  11. Measurements of Radon Concentration in Yemen Using Spark Counter

    International Nuclear Information System (INIS)

    Arafa, W.; Abou-Leila, M.; Hafiz, M.E.; Al-Glal, N.

    2011-01-01

    Spark counter has been designed and realized and the optimum applied voltage was found to be 600 V. Excellent consistent agreements was observed between counted number of tracks by spark counter and reading by optical microscope. Radon concentration in some houses in Sana'a and Hodeidah cities in Yemen had been performed using LR-115 SSNTD and spark counter system. The average radon concentration in both cities was far lower the alert value. The results showed that radon concentration in the metropolitan area Sana'a was higher than that in Hodeidah city. Also, it was observed that old residential houses had higher levels of radon concentrations have compared to newly built houses in the metropolitan area Sana'a

  12. Investigations of radon and radon daughters in surficial aquifers of florida

    International Nuclear Information System (INIS)

    1991-05-01

    The principal purpose of the investigation was to test the hypothesis that radon soil flux, considered the principal source of indoor radon contamination, has an underlying relationship to the radon content of associated shallow groundwaters. The working hypothesis was that radon build-up in both soil and shallow groundwater is basically a consequence of the same factor, radon emanation from soil grains and the solid surfaces of the aquifers. Groundwater may be advantageous as an indicator of radon potential. Another object of the project was to investigate temporal and spatial trends of radon daughter products in shallow aquifers. After analyzing all of the radon soil, flux, and groundwater measurements made over the two-year study period, it is clear that while there is no direct relationship between either radon soil concentration or flux and groundwater radon. Measurements in wells where polonium is present at very high concentrations have shown that 210Po is largely unsupported by its radioactive predecessor, and that polonium is considerably more variable, in both space and time than other parameters measured in the same wells, including radon

  13. Radon dosimetry: a review of radon and radon daughter exposure conditions in dwellings and other structures

    International Nuclear Information System (INIS)

    Ryan, M.T.; Goldsmith, W.A.; Poston, J.W.; Haywood, F.F.; Witherspoon, J.P.

    1983-07-01

    Within the past few years several situations have been brought to light which indicate an increased radiation exposure of certain segments of the general population caused by human activities. The most widely publicized activities are those associated with the mining and milling of uranium in the western United States, the phosphate industry in Florida, and those potential problems represented by former Manhattan Engineer District sites. One of the primary problems involves exposure to radon and radon daughters which are released from large waste piles or, in some cases, evolve from backfill and construction materials used in homes, schools, and other buildings. This report presents a review of the available data on radon and radon daughter concentrations in dwellings and other structures. The primary objectives were to compile and tabulate pertinent radon exposure data and to prepare a statistical summary of the data which will be useful in the prediction of normal levels of radon and radon daughter concentrations in these structures. In addition, other parameters associated with radon exposure conditions are presented and discussed

  14. Radon compensation for alpha air monitoring systems

    International Nuclear Information System (INIS)

    Fleming, D.M.; Rising, F.L.; Zuerner, L.V.

    1975-01-01

    Continuous alpha air monitors, employing solid state detectors and single channel analyzers, for the detection of alpha particles of a specific energy have been available commercially for several years. The single channel pulse height analyzers provide good sensitivity to the isotope of interest and reject much of the unwanted activity from other isotopes such as naturally occurring radon and daughters. A small percentage of the radon daughters are degraded in energy by the air between the collecting filter and the diode to the extent that they coincide with energy of the isotope being measured and are counted as unwanted background. When 239 Pu is the isotope being measured the activity in the Pu channel resulting from radon is typically 2 percent of the total radon background. The majority of this unwanted background results from the degradation of the 6.0 MeV 218 Po (RaA) peak. This background is sufficient to cause instrument alarms during periods of radon activity. In attempts to reduce the frequency of false alarms, background subtraction circuits have been added as standard equipment to most of the alpha air monitors available on the market for the past several years. A method for calibrating these background subtraction circuits using a radon generator is described. (U.S.)

  15. Distance to High-Voltage Power Lines and Risk of Childhood Leukemia – an Analysis of Confounding by and Interaction with Other Potential Risk Factors

    DEFF Research Database (Denmark)

    Pedersen, Camilla; Bräuner, Elvira V; Rod, Naja Hulvej

    2014-01-01

    . We used geographical information systems to determine the distance between residence at birth and the nearest 132-400 kV overhead power line. Concentrations of domestic radon and traffic-related air pollution (NOx at the front door) were estimated using validated models. We found a statistically......We investigated whether there is an interaction between distance from residence at birth to nearest power line and domestic radon and traffic-related air pollution, respectively, in relation to childhood leukemia risk. Further, we investigated whether adjusting for potential confounders alters...

  16. Radon Monitoring in Army Stand-Alone Housing Units

    Science.gov (United States)

    1990-04-01

    damage lung tissue and lead I to increased risk of developing lang cancer . Your risk of developing lung cancer from exposure to radon depends upon the...of developing lung cancer than exposure to a significantly elevated level for a short time. In general, your risk increases as the level of radon and...000mm 0Mmm *000 OOO 0 0w 0 0 000 -0-0 *4 0 880 mama 0 0000000000 000 000Eca ( el cN) 00 9 ’ qqO .00 1(10 0 -U M w co SEE wSS SEES NSEwESO m v MM O v mm

  17. Radon-Nikodym derivatives of quantum operations

    International Nuclear Information System (INIS)

    Raginsky, Maxim

    2003-01-01

    Given a completely positive (CP) map T, there is a theorem of the Radon-Nikodym type [W. B. Arveson, Acta Math. 123, 141 (1969); V. P. Belavkin and P. Staszewski, Rep. Math. Phys. 24, 49 (1986)] that completely characterizes all CP maps S such that T-S is also a CP map. This theorem is reviewed, and several alternative formulations are given along the way. We then use the Radon-Nikodym formalism to study the structure of order intervals of quantum operations, as well as a certain one-to-one correspondence between CP maps and positive operators, already fruitfully exploited in many quantum information-theoretic treatments. We also comment on how the Radon-Nikodym theorem can be used to derive norm estimates for differences of CP maps in general, and of quantum operations in particular

  18. Air pressure distribution and radon entry processes in east Tennessee schools

    International Nuclear Information System (INIS)

    Sinclair, L.D.; Dudney, C.S.; Wilson, D.L.; Saultz, R.J.

    1990-01-01

    Many building characteristics have been found to influence radon entry, including building size and configuration, substructure, location of utility supply lines, and design and operation of the heating, ventilation, and air conditioning (HVAC) system. One of the most significant factors is room depressurization resulting from the HVAC system exhausting more than it supplies. This paper represents a preliminary assessment of HVAC characteristics and how they may relate to radon entry. During the summer of 1989, a limited survey was made of air pressure and radon levels in four schools in eastern Tennessee. Short-term samples of radon and pressure were made in all rooms in contact with the soil using alpha scintillation cells and an electronic microanometer, respectively. The pressure difference and radon concentration changes induced by operation of the building ventilation system varied among sites within individual schools

  19. Background concentrations of radon and radon daughters in Canadian homes

    International Nuclear Information System (INIS)

    McGregor, R.G.; Vasudev, P.; Letourneau, E.G.; McCullough, R.S.; Prantl, F.A.; Taniguchi, H.

    1980-01-01

    Measurements of radon and radon daughters were carried out in 14 Canadian cities on a total of 9999 homes selected in a statistically random manner. The geometric means of the different cities varied from 0.14 to 0.88 pCi/l. for radon and 0.0009 to 0.0036 Working Levels for radon daughters. The radon originates from natural radioactivity in the soil surrounding the homes. (author)

  20. Application of the inter-line PCR for the analyse of genomic rearrangements in radiation-transformed mammalian cell lines

    International Nuclear Information System (INIS)

    Leibhard, S.; Smida, J.

    1996-01-01

    Repetitive DNA sequences of the LINE-family (long interspersed elements) that are widely distributed among the mammalian genome can be activated or altered by the exposure to ionizing radiation [1]. By the integration at new sites in the genome alterations in the expression of genes that are involved in cell transformation and/or carcinogenesis may occur [2, 3]. A new technique -the inter-LINE PCR - has been developed in order to detect and analyse such genomic rearrangements in radiation-transformed cell lines. From the sites of transformation- or tumour-specific changes in the genome it might be possible to develop new tumour markers for diagnostic purpose. (orig.) [de

  1. Radon exposure of passengers in the Prague metro

    International Nuclear Information System (INIS)

    Sabol, J.

    1996-01-01

    This paper summarises the results of radon concentration monitoring in the carriages and at some stations of the Prague Metro network. The measurements revealed that radon levels in the Metro are relatively low in comparison to those normally encountered in dwellings in the Prague region. On average, the radon concentrations in the air inside the carriages have been found to be about 11 - 12 Bq m -3 while the levels at most stations reached values between 10 and 15 Bq m -3 . The Metro is intensively ventilated by means of powerful blowers and fans; the piston effect of the moving trains also contributes to air exchange. The ventilation rate is typically 3-4 h -1 . The highest rate is in line C, where the air in all underground areas is completely exchanged 6 times within each hour. These results demonstrate that Metro passengers receive about the same effective dose as passengers using surface transport. The doses from radon in the metro are only slightly higher than radon-related doses in the open air, while exposure due to external photon radiation seems to be a few percent lower than dose rates common in typical Czech houses. (author)

  2. Radon in public buildings; Radon in oeffentlichen Gebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, H.; Flesch, K. [IAF - Radiooekologie GmbH, Dresden (Germany); Hermann, E. [B.P.S. Engineering GmbH, Zwickau (Germany); Loebner, W. [Wismut GmbH, Chemnitz (Germany); Leissring, B. [Bergtechnisches Ingenieurbuero GEOPRAX, Chemnitz (Germany)

    2009-07-01

    From the Free State of Saxony, a study was commissioned to survey how reliable measurements to characterize the radon situation in public buildings at a reasonable financial and human effort can be carried out to reduce radiation exposure in public buildings. The study approach was for 6 objects. To characterize the radon situation the time evolution measurement of radon concentrations of more than 1 to 2 weeks turned out to be sufficient. A novel data analysis enables the identification of a ''typical daily alteration of the radon concentration'' depending on the ventilation conditions and the daily use of the offices or class rooms. The identification of typical diurnal radon variations for the working time and weekends or holidays is of fundamental importance for assessing the exposure situation in public buildings. It was shown that the radon concentration during working time are in general much lower than in the times when the buildings (offices) are unused. It turned out that the long-term radon measurements with nuclear track detectors within distinct time regimes (day / night, working hours / leisure time) by utilizing switch modules are very efficient to estimate the actual exposure. (orig.)

  3. Radon in Austria

    International Nuclear Information System (INIS)

    Friedmann, H.

    2000-01-01

    Several projects in Austria deal with the problem of enhanced radon exposure to the public. The Austrian Radon Project is the largest project within this task, with the aim of investigating the radon concentrations in Austrian homes. Another project concerns mitigation methods. According to the EU directive EURATOM 96/29 it is also necessary to check working places for possibly enhanced radon concentrations. These projects are and will be funded by the government. The federal government of Upper Austria sponsored a project to test the indoor air quality in kindergartens including radon measurements. Within an EU research project, the radon concentrations in Austrian springs and groundwater were systematically listed and analyzed. Additional investigations will focus on methods to improve the radon potential maps from the Austrian Radon Project by including geological and other information. (author)

  4. 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

  5. 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

  6. A Fast Algorithm of Generalized Radon-Fourier Transform for Weak Maneuvering Target Detection

    Directory of Open Access Journals (Sweden)

    Weijie Xia

    2016-01-01

    Full Text Available The generalized Radon-Fourier transform (GRFT has been proposed to detect radar weak maneuvering targets by realizing coherent integration via jointly searching in motion parameter space. Two main drawbacks of GRFT are the heavy computational burden and the blind speed side lobes (BSSL which will cause serious false alarms. The BSSL learning-based particle swarm optimization (BPSO has been proposed before to reduce the computational burden of GRFT and solve the BSSL problem simultaneously. However, the BPSO suffers from an apparent loss in detection performance compared with GRFT. In this paper, a fast implementation algorithm of GRFT using the BSSL learning-based modified wind-driven optimization (BMWDO is proposed. In the BMWDO, the BSSL learning procedure is also used to deal with the BSSL phenomenon. Besides, the MWDO adjusts the coefficients in WDO with Levy distribution and uniform distribution, and it outperforms PSO in a noisy environment. Compared with BPSO, the proposed method can achieve better detection performance with a similar computational cost. Several numerical experiments are also provided to demonstrate the effectiveness of the proposed method.

  7. Predictors of Indoor Radon Concentrations in Pennsylvania, 1989-2013.

    Science.gov (United States)

    Casey, Joan A; Ogburn, Elizabeth L; Rasmussen, Sara G; Irving, Jennifer K; Pollak, Jonathan; Locke, Paul A; Schwartz, Brian S

    2015-11-01

    Radon is the second-leading cause of lung cancer worldwide. Most indoor exposure occurs by diffusion of soil gas. Radon is also found in well water, natural gas, and ambient air. Pennsylvania has high indoor radon concentrations; buildings are often tested during real estate transactions, with results reported to the Department of Environmental Protection (PADEP). We evaluated predictors of indoor radon concentrations. Using first-floor and basement indoor radon results reported to the PADEP between 1987 and 2013, we evaluated associations of radon concentrations (natural log transformed) with geology, water source, building characteristics, season, weather, community socioeconomic status, community type, and unconventional natural gas development measures based on drilled and producing wells. Primary analysis included 866,735 first measurements by building, with the large majority from homes. The geologic rock layer on which the building sat was strongly associated with radon concentration (e.g., Axemann Formation, median = 365 Bq/m3, IQR = 167-679 vs. Stockton Formation, median = 93 Bq/m3, IQR = 52-178). In adjusted analysis, buildings using well water had 21% higher concentrations (β = 0.191, 95% CI: 0.184, 0.198). Buildings in cities (vs. townships) had lower concentrations (β = -0.323, 95% CI: -0.333, -0.314). When we included multiple tests per building, concentrations declined with repeated measurements over time. Between 2005 and 2013, 7,469 unconventional wells were drilled in Pennsylvania. Basement radon concentrations fluctuated between 1987 and 2003, but began an upward trend from 2004 to 2012 in all county categories (p Pennsylvania, 1989-2013. Environ Health Perspect 123:1130-1137; http://dx.doi.org/10.1289/ehp.1409014.

  8. Inhibition of iron uptake is responsible for differential sensitivity to V-ATPase inhibitors in several cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Sarah Straud

    2010-07-01

    Full Text Available Many cell lines derived from tumors as well as transformed cell lines are far more sensitive to V-ATPase inhibitors than normal counterparts. The molecular mechanisms underlying these differences in sensitivity are not known. Using global gene expression data, we show that the most sensitive responses to HeLa cells to low doses of V-ATPase inhibitors involve genes responsive to decreasing intracellular iron or decreasing cholesterol and that sensitivity to iron uptake is an important determinant of V-ATPase sensitivity in several cancer cell lines. One of the most sensitive cell lines, melanoma derived SK-Mel-5, over-expresses the iron efflux transporter ferroportin and has decreased expression of proteins involved in iron uptake, suggesting that it actively suppresses cytoplasmic iron. SK-Mel-5 cells have increased production of reactive oxygen species and may be seeking to limit additional production of ROS by iron.

  9. Isolation of fungal homokaryotic lines from heterokaryotic transformants by sonic disruption of mycelia.

    Science.gov (United States)

    Bashi, Zafer Dallal; Khachatourians, George; Hegedus, Dwayne Daniel

    2010-01-01

    Fungal hyphae--and in some cases, spores--are multi-nucleate. During genetic transformation of these spores or mycelia, only one nucleus generally receives the transferred T-DNA generating heterokaryotic colonies. Characterization of genetic changes, such as the effects of gene disruption in the transformants, requires purified homokaryotic lines. Hyphal tip transfer has conventionally been used to isolate homokaryons. We developed an alternative method for purification of fungal homokaryons from transformed heterokaryotic lines of Sclerotinia sclerotiorum. Ultrasound pulses were used to generate bi-septate, unicellular hyphal fragments that regenerate under selection to produce homokaryotic lines that can be easily identified using colony PCR. This technique facilitates the purification of transformed lines, which allows for routine genome manipulation, and should be adaptable for other filamentous fungi.

  10. A continuous monitor for the measurement of environmental radon

    International Nuclear Information System (INIS)

    Chittaporn, P.; Eisenbud, M.; Harley, N.H.

    1981-01-01

    Although inhaled short-lived 222 Rn daughters deliver the pertinent α dose for assessing human health effects, radon daughters do not of themselves exist in any atmosphere for more than 2-3 hr. Their long-lived parent (3.82 day) 222 Rn supports the daughter activity and it is the transport of 222 Rn which ultimately determines dose. Without an understanding of the long and short-term temporal patterns of indoor and outdoor 222 Rn it is impossible to understand the factors which are important in establishing any human health hazard from the daughters. This work describes a new continuous environmental radon monitor which measures radon alone without interference from radon daughters. The detector is a cylinder (13 cm diameter x 14 cm high), is lined with alpha scintillation phospor on a Mylar substrate and is portable and easily constructed from inexpensive and commercially available materials. (author)

  11. The effect of bright lines in environmental risk communication

    International Nuclear Information System (INIS)

    Wilson, K.N.; Desvousges, W.H.; Smith, K.V.; Payne, J.

    1993-01-01

    Bright lines in environmental risk communication refer to the specific levels at which an environmental risk becomes a serious health threat and action should be taken to mitigate its effects. This study examined the effect of ''bright lines'' in risk communication by emphasizing the radon exposure threshold level of 4 picocuries per liter. Specifically, the authors developed a computer-assisted interview containing bright-line versions of risk information. The bright-line version contained a range of possible radon levels, the corresponding number of estimated lung cancer cases, the relative health risk from radon compared to other health risks, and the EPA guidelines for mitigating levels above 4 picocuries in the home. The non-bright line version was identical to the bright-line version, except it did not include the EPA's mitigation recommendations. Effect measures included respondents' change in perceived risk after reading their materials, intended testing behavior, and advice to their neighbor for a specified radon level either above or below the 4 picocury threshold level. This paper discusses broader policy implications for designing effective risk communication programs

  12. On-line meters monitor gas concentrations in transformers

    Energy Technology Data Exchange (ETDEWEB)

    Pirhonen, R.; Lustre, L. [ed.

    1997-11-01

    Power transformers are by far the most expensive single components of 400 kV transmission grid substations. The acquisition price of a transformer is about FIM 15 to 20 million. A good way to extend the service life of a transformer considerably is to conduct a general overhaul. The cornerstone of cost-efficient maintenance is the correct timing of the general overhaul, which usually costs a couple million Finnish marks

  13. Radon measurements during the building of a low-level laboratory

    CERN Document Server

    Antanasijevic, R; Bikit, I; Banjanac, R; Dragic, A; Joksimovic, D; Krmpotic, D; Udovicic, V; Vukovic, J

    1999-01-01

    Radon measurements were provided during the different stages of building of a low-level laboratory in Belgrade. The depth of the laboratory is 12 m, equivalent to 30 m of water with an area of 45 m sup 2. The whole of the laboratory is hermetically lined with 1 mm A1 foil and is ventilated with filtered air. Radon concentrations were measured with the CR-39 detector as well as via the gamma-ray spectroscopic measurements. The radon concentrations in the air were achieved to 20 Bqm sup - sup 3 and reduction of secondary and tertiary cosmic-ray fluxes is five times when ventilation, filtering and sealing was applied.

  14. Radon measurements during the building of a low-level laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Antanasijevic, R.; Anicin, I.; Bikit, I.; Banjanac, R.; Dragic, A.; Joksimovic, D.; Krmpotic, D.; Udovicic, V.; Vukovic, J

    1999-06-01

    Radon measurements were provided during the different stages of building of a low-level laboratory in Belgrade. The depth of the laboratory is 12 m, equivalent to 30 m of water with an area of 45 m{sup 2}. The whole of the laboratory is hermetically lined with 1 mm A1 foil and is ventilated with filtered air. Radon concentrations were measured with the CR-39 detector as well as via the gamma-ray spectroscopic measurements. The radon concentrations in the air were achieved to 20 Bqm{sup -3} and reduction of secondary and tertiary cosmic-ray fluxes is five times when ventilation, filtering and sealing was applied.

  15. Radon measurements during the building of a low-level laboratory

    International Nuclear Information System (INIS)

    Antanasijevic, R.; Anicin, I.; Bikit, I.; Banjanac, R.; Dragic, A.; Joksimovic, D.; Krmpotic, D.; Udovicic, V.; Vukovic, J.

    1999-01-01

    Radon measurements were provided during the different stages of building of a low-level laboratory in Belgrade. The depth of the laboratory is 12 m, equivalent to 30 m of water with an area of 45 m 2 . The whole of the laboratory is hermetically lined with 1 mm A1 foil and is ventilated with filtered air. Radon concentrations were measured with the CR-39 detector as well as via the gamma-ray spectroscopic measurements. The radon concentrations in the air were achieved to 20 Bqm -3 and reduction of secondary and tertiary cosmic-ray fluxes is five times when ventilation, filtering and sealing was applied

  16. Estimation of radon emanation coefficient for soil and flyash

    International Nuclear Information System (INIS)

    Sahu, S.K.; Swarnkar, M.; Ajmal, P.Y.; Pandit, G.G.; Puranik, V.D.

    2012-01-01

    Since terrestrial materials include radium ( 226 Ra) originating from the decay of uranium ( 238 U), all such materials release radon ( 222 Rn) to varying degrees. When a radium atom decays to radon, the energy generated is strong enough to send the radon atom a distance of about 40 nanometers-this is known as alpha recoil. For a radon atom to escape the radium atom must be within the recoil distance from the grain surface of flyash or soil and the direction of recoil must send the radon atom toward the outside of the grain. Therefore, all of the radon atoms generated by the radium contained in flyash or soil grain are actually not released into pore spaces and mobilized. The fraction of radon atoms generated from radium decay that are released from into flyash or soil pore space is defined as the radon emanation coefficient or emanating power, of the material. Grain size and shape are two of the important factors that control the radon emanation coefficient because they determine in part how much uranium and radium is near enough to the surface of the grain to allow the newly-formed radon to escape into a pore space. In a porous medium, where the radon is in radioactive equilibrium with its parent radium, the emanation coefficient is given by the expression: where C 0 is the undiluted radon activity concentration in the pores of the medium, and C Ra is the radium activity concentration of the sample. The 226 Ra activity concentration of the flyash and soil sample were determined by using the g-spectrometry. C 0 was determined by the can experiment using LR-115 for flyash and soil samples. The C 0 values for flyash and soil samples were found to be 245.7 Bq/m 3 and 714.3 Bq/m 3 respectively. The radon emanation coefficient for flyash was found to be 0.0024 while that for soil was 0.0092. Therefore the soil sample was found to be four times higher radon emanation coefficient than flyash which is in line with the results reported in the literatures. This may suggest

  17. Radon and lung cancer in Bangalore Metropolitan, India

    International Nuclear Information System (INIS)

    Sathish, L.A.; Nethravathi, K.S.; Ramachandran, T.V.

    2012-01-01

    Radon is a radioactive gas released from the normal decay of 238 U in rocks and soil. It is an invisible, odorless, tasteless gas that seeps up through the ground and diffuses into the air. In a few areas, depending on local geology, radon dissolves into ground water and can be released into the air when the water is used. Radon gas usually exists at very low levels outdoors. However, in areas without adequate ventilation, such as underground mines, radon can accumulate to levels that substantially increase the risk of lung cancer. Radon decays quickly, giving off tiny radioactive particles. When inhaled, these radioactive particles can damage the cells that line the lung. Long-term exposure to radon can lead to lung cancer, the only cancer proven to be associated with inhaling radon. Public interest in radon has been occasionally piqued by articles in the general press. Considerable attention has been given to the high radon levels that were uncovered in the Reading Prong region of Pennsylvania, following the discovery in late 1984 of extremely high levels in one home. Several epidemiological study programmes in different countries are in progress to estimate the population exposures due to natural radiation with a view to obtain the radiation risk coefficients at low dose rate levels. In this regard, radiation surveys in high background areas (HBRAs) can provide excellent settings for epidemiological studies relating to the effects of low doses of radiation. In view of these, a comprehensive estimate of the natural inhalation dose requires both 222 Rn and 220 Rn levels in the indoor atmosphere. In this outlook an attempt is made to investigate the 222 Rn and 220 Rn levels in dwellings of Bangalore Metropolitan, India. Three year results shows that the activity concentrations of 226 Ra, 232 Th, radon in ground water, the concentrations 222 Rn and 220 Rn and the dose rate (mSvy -1 ) are at alarming levels for the environment of Bangalore Metropolitan, India. The

  18. 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

  19. Radon reduction and radon-resistant construction demonstrations in New York state. Final report

    International Nuclear Information System (INIS)

    1991-02-01

    A survey of radon levels in New York State homes indicates that approximately 4.4 percent of the homes have long-term living area radon concentrations above the U.S. EPA guideline of four pCi/l. The project addressed the effectiveness of techniques to reduce the radon level in existing homes and to prevent the occurrence of high radon concentrations in new homes. The goal of the project was to demonstrate the effectiveness of radon reduction techniques in homes containing indoor radon concentrations of more than the current EPA guidelines of four pCi/l. At the same time, radon-resistant construction techniques were demonstrated in homes under construction to provide guidelines for houses being built in areas with a danger of high radon levels. The project demonstrated new radon mitigation techniques in homes containing indoor radon concentrations exceeding four pCi/l; assessed the value of previously installed radon reduction procedures, and demonstrated new radon-resistant construction methods

  20. 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

  1. Evaluation of experiences in long-term radon and radon-daughter measurements

    International Nuclear Information System (INIS)

    Young, J.A.; Jackson, P.O.; Thomas, V.W.

    1982-12-01

    Pacific Northwest Laboratory (PNL) is performing side-by-side measurements of radon and radon daughter concentrations using several instruments and techniques, and is comparing these measurements with side-by-side measurements made by other investigators at other locations. The standard deviation of the differences between the (natural) logarithms of the Terradex Track Etch radon concentrations and the logarithms of the Radon Progency Integrating Sampling Units (RPISU) radon daughter concentrations (S.D.-ln) measured in 50 buildings in Edgemont, South Dakota, was 0.37. Using this S.D.-ln, it can be calculated that if the Track Etch radon daughter concentration is 0.010 WL there should be only a 14% probability that the RPISU average would be greater than 0.015 WL, and only a 3% probability tht the RPISU average would be greater than 0.020 WL. If buildings had been cleared from remedial action when the Track Etch averages were less than 0.10 WL, then about 61% of the buildings would have been cleared from remedial action, and only a few percent of these buildings would have actually had average RPISU concentrations greater than 0.015 WL. The S.D.-ln between the Track Etch radon measurements and the RPISU radon daughter measurements made by ALARA at Grand Junction, the PERM radon measurements and the MOD-225 radon daughter measurements made by Mound Facility at Canonsburg and Middlesex, and the PERM and Track Etch radon measurements made by Mound Facility at Salt Lake City were similar to the S.D.-ln between the Track Etch radon measurements and the RPISU radon daughter measurements at Edgemont

  2. Radon entry into a simple test structure

    DEFF Research Database (Denmark)

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

    1992-01-01

    A simple test structure for studies of radon entry into houses has been constructed at a field site at Riso National Laboratory. It consists of a 40 1, stainless-steel cylinder placed in a 0.52 m deep quadratic excavation with a side length of 2.4 m. The excavation is lined with an airtight...... membrane, and soil gas enters the cylinder through a changeable interface in the bottom. The depressurisation of the cylinder is controlled by a mass-flow controller, thereby limiting the influence of natural driving forces. Pressures, temperatures and radon concentrations are measured continuously...... in the cylinder and in selected locations in the soil. In this paper, the test structure is described, and initial results concerning the transport of soil gas and radon under steady-state conditions are reported. It is found that the soil in the vicinity of the structure is partially depleted with respect...

  3. Application of single-chip microcomputer to portable radon and radon daughters monitor

    International Nuclear Information System (INIS)

    Meng Yecheng; Huang Zhanyun; She Chengye

    1992-01-01

    Application of single-chip microcomputer to portable radon and radon daughters monitor is introduced in this paper. With the single-chip microcomputer automation comes into effect in the process from sampling to measuring of radon and radon daughters. The concentrations of radon and radon daughters can be easily shown when the conversion coefficients are pre-settled before the measurement. Moreover, the principle and design are briefly discussed according to the characteristics of the monitor

  4. 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

  5. Method and algorithm for image processing

    Science.gov (United States)

    He, George G.; Moon, Brain D.

    2003-12-16

    The present invention is a modified Radon transform. It is similar to the traditional Radon transform for the extraction of line parameters and similar to traditional slant stack for the intensity summation of pixels away from a given pixel, for example ray paths that spans 360 degree at a given grid in the time and offset domain. However, the present invention differs from these methods in that the intensity and direction of a composite intensity for each pixel are maintained separately instead of combined after the transformation. An advantage of this approach is elimination of the work required to extract the line parameters in the transformed domain. The advantage of the modified Radon Transform method is amplified when many lines are present in the imagery or when the lines are just short segments which both occur in actual imagery.

  6. 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.

  7. 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

  8. 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)

  9. Wigner distribution and fractional Fourier transform

    NARCIS (Netherlands)

    Alieva, T.; Bastiaans, M.J.; Boashash, B.

    2003-01-01

    We have described the relationship between the fractional Fourier transform and the Wigner distribution by using the Radon-Wigner transform, which is a set of projections of the Wigner distribution as well as a set of squared moduli of the fractional Fourier transform. We have introduced the concept

  10. Wind direction correlated measurements of radon and radon progeny in atmosphere: a method for radon source identification

    International Nuclear Information System (INIS)

    Akber, R.A.; Pfitzner, J.; Johnston, A.

    1994-01-01

    This paper describes the basic principles and methodology of a wind direction correlated measurement technique which is used to distinguish the mine-related and background components of radon and radon progeny concentrations in the vicinity of the ERA Ranger Uranium Mine. Simultaneous measurements of atmospheric radon and radon progeny concentrations and wind speed and direction were conducted using automatic sampling stations. The data were recorded as a time series of half hourly averages and grouped into sixteen 22.5 degrees wind sectors. The sampling interval and the wind sector width were chosen considering wind direction variability (σ θ ) over the sampling time interval. The data were then analysed for radon and radon progeny concentrations in each wind sector. Information about the wind frequency wind speed seasonal and diurnal variations in wind direction and radon concentrations was required for proper data analysis and interpretation of results. A comparison with model-based estimates for an identical time period shows agreement within about a factor of two between the two methods. 15 refs., 1 tab., 5 figs

  11. Instruments to measure radon activity concentration or exposure to radon. Interlaboratory comparison 2011

    International Nuclear Information System (INIS)

    Foerster, Elisabeth; Beck, Thomas; Buchroeder, Helmut; Doering, Joachim; Schmidt, Volkmar

    2011-10-01

    According to the Directive 96/29/EURATOM the monitoring of occupational radiation exposures shall base on individual measurements carried out by an approved dosimetric service. Pursuant to the European Directive an approved dosimetric service is a body responsible for the calibration, reading or interpretation of individual monitoring devices.., whose capacity to act in this respect is recognized by the competent authorities. This concept will also be applied to radon services issuing passive radon measurement devices. Passive radon measurement devices 1 using solid state nuclear track detectors or electrets are recommended for individual monitoring of exposures to radon. German regulations lay down that radon measuring devices are appropriate for purposes of occupational radiation monitoring if the devices are issued by recognized radon measurement services, and the measurement service submits devices of the same type issued for radon monitoring to regular intercomparisons conducted by BfS. A radon measuring service is recognized by the competent authority if it proves its organizational and technical competence, e. g. by accreditation. These regulations have been introduced in the area of occupational radiation exposures. Nevertheless, it is recommended that radon measuring services which carry out radon measurements in other areas (e.g. dwellings) should subject themselves to these measures voluntarily. The interlaboratory comparisons comprise the organization, exposure, and evaluation of measurements of radon activity concentration or exposure to radon. The comparisons only concern radon-222; radon-220 is not in the scope. Radon services being interested can get further information from the website www.bfs.de/de/ion/radon/fachinfomessung/vergleichspruefungen.html and from the European Information System on Proficiency Testing Schemes (eptis) available in the internet. (orig.)

  12. Uncertainties of estimating average radon and radon decay product concentrations in occupied houses

    International Nuclear Information System (INIS)

    Ronca-Battista, M.; Magno, P.; Windham, S.

    1986-01-01

    Radon and radon decay product measurements made in up to 68 Butte, Montana homes over a period of 18 months were used to estimate the uncertainty in estimating long-term average radon and radon decay product concentrations from a short-term measurement. This analysis was performed in support of the development of radon and radon decay product measurement protocols by the Environmental Protection Agency (EPA). The results of six measurement methods were analyzed: continuous radon and working level monitors, radon progeny integrating sampling units, alpha-track detectors, and grab radon and radon decay product techniques. Uncertainties were found to decrease with increasing sampling time and to be smaller when measurements were conducted during the winter months. In general, radon measurements had a smaller uncertainty than radon decay product measurements. As a result of this analysis, the EPA measurements protocols specify that all measurements be made under closed-house (winter) conditions, and that sampling times of at least a 24 hour period be used when the measurement will be the basis for a decision about remedial action or long-term health risks. 13 references, 3 tables

  13. Radon programme: presence and future

    International Nuclear Information System (INIS)

    Hulka, J.

    2009-01-01

    In this presentation an overview of radon programme experiences is presented. The paper summarises national radon policy, national programmes, legislation, the role of preventive measures and interventions with respect to existing and future exposure and knowledge of radon risk, problems of remediation strategies, practical protection in dwellings, radon measurements strategies, progress in radon measurement of an individual house (radon diagnosis), radon mapping process and sense of delineation of radon prone areas, natural radioactivity of building materials and radioactivity in public water and their role in the radon programme, public awareness on radon issue and publicity campaign. Some research activities are proposed aiming at effective solutions of radon issues in future

  14. Protective measures during construction against radon exposure

    International Nuclear Information System (INIS)

    Horn, W.

    1990-01-01

    Radon, thoron as well as their daughter products have an cancerogeneous effect on the human respiratory tracts. In this respect protective measures in the area of construction are of great importance. This article deals with constructional solutions which consist of different individual measures. Sources of radon are outside air, water, fuels, building materials as well as the building ground. Possible protective measures are divided into area-related (floor structure, intermediate floors, exterior walls of cellar, foundation slab, building ground), line-related (joints, cracks, wall ducts) as well as supplementary measures (tightly closing doors, arrangement of natural cross-ventilation and vertical ventilating shafts). (BWI) [de

  15. 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)

  16. A survey of radon properties in underground railway stations in Hong Kong

    International Nuclear Information System (INIS)

    Yu, K.N.; Young, E.C.M.; Wong, K.C.

    1996-01-01

    A number of properties related to radon have been surveyed in underground railway stations in Hong Kong. These properties include the radon concentration, the total potential alpha energy concentration of radon daughters and the equilibrium factor. The mean values were different from those of dwelling sites, and the values for different railway lines were also very different, attributable to the different ventilation efficiencies and aerosol concentrations. The values for a chosen station were observed to have temporal variation in the morning, since the air-conditioning is switched off at night. From the measurements, sample calculations of the radon dose received by different categories of people were performed. It is seen that the radon dose received by the night time maintenance worker was not insignificant, that received by an average commuter was negligible while that received by a day time employee was between the two. (author)

  17. Radon concentration distributions in shallow and deep groundwater around the Tachikawa fault zone.

    Science.gov (United States)

    Tsunomori, Fumiaki; Shimodate, Tomoya; Ide, Tomoki; Tanaka, Hidemi

    2017-06-01

    Groundwater radon concentrations around the Tachikawa fault zone were surveyed. The radon concentrations in shallow groundwater samples around the Tachikawa fault segment are comparable to previous studies. The characteristics of the radon concentrations on both sides of the segment are considered to have changed in response to the decrease in groundwater recharge caused by urbanization on the eastern side of the segment. The radon concentrations in deep groundwater samples collected around the Naguri and the Tachikawa fault segments are the same as those of shallow groundwater samples. However, the radon concentrations in deep groundwater samples collected from the bedrock beside the Naguri and Tachikawa fault segments are markedly higher than the radon concentrations expected from the geology on the Kanto plane. This disparity can be explained by the development of fracture zones spreading on both sides of the two segments. The radon concentration distribution for deep groundwater samples from the Naguri and the Tachikawa fault segments suggests that a fault exists even at the southern part of the Tachikawa fault line. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Radon emanation from soils

    International Nuclear Information System (INIS)

    Markkanen, M.; Arvela, H.

    1992-01-01

    The results of gamma spectrometric sample measurements of radon ( 222 Rn) emanation coefficients and radium concentrations ( 226 Ra) from about 800 Finnish soil samples are presented. The radon emanation rate was measured in about 400 soil samples, using radon-tight cans and Lucas cells. The effects of water content and temperature on radon emanation were investigated, using various samples of different soil types. Radon emanation and the effect of water content on radon emanation were investigated separately for different grain sizes (samples of till). The results provide some information on radon emanation in different soil types and relate emanation in laboratory conditions to conditions in ground soil. In routine measurements of radon emanation from soil samples, use of a 5% water content was considered advisable. The correction coefficients of radon emanation varied between 0.3 and 1.5, depending on the water content and soil type. At 5% water content, hardly any difference was found between radon emanation at temperatures of 20 and 1 o C. Radon emanation was found to be an inverse function of grain sizes larger than 0.5 mm in diameter. (author)

  19. Radon detection system, design, test and performance

    International Nuclear Information System (INIS)

    Balcazar, M.; Chavez, A.; Pina-Villalpando, G.; Navarrete, M.

    1999-01-01

    A portable radon detection system (α-Inin) has been designed and constructed for using it in adverse environmental conditions where humidity, temperature and chemical vaporous are present. The minimum integration time is in periods of 15 min during 41 days. A 12 V battery and a photovoltaic module allow the α-Inin autonomy in field measurements. Data is collected by means of a laptop computer where data processing and α-Inin programming are carried out. α-Inin performance was simultaneously tested in a controlled radon chamber, together with a commercial α-Meter

  20. Radiation exposure due to radon and radon daughters

    International Nuclear Information System (INIS)

    Ullmann, W.

    1976-01-01

    Underground miners working over long periods of time in mines with a high content of radon and radon daughters belong to that group of occupationally exposed persons who are subject to the greatest somatic risk, with values especially high if the permissible dose limits are exceeded. Follwing an overview of the permissible limits currently in use for radon and radon daughters as well as the results of examinations performed in nationally-owned underground mining of the G.D.R., considerations are presented on the measuring quantities requisite for statistical, control and safety measurements in this field. Finally, conclusions are drawn concerning the measuring procedures and instruments to be employed for practical work. (author)

  1. Airflow measurement techniques applied to radon mitigation problems

    International Nuclear Information System (INIS)

    Harrje, D.T.; Gadsby, K.J.

    1989-01-01

    During the past decade a multitude of diagnostic procedures associated with the evaluation of air infiltration and air leakage sites have been developed. The spirit of international cooperation and exchange of ideas within the AIC-AIVC conferences has greatly facilitated the adoption and use of these measurement techniques in the countries participating in Annex V. But wide application of such diagnostic methods are not limited to air infiltration alone. The subject of this paper concerns the ways to evaluate and improve radon reduction in buildings using diagnostic methods directly related to developments familiar to the AIVC. Radon problems are certainly not unique to the United States, and the methods described here have to a degree been applied by researchers of other countries faced with similar problems. The radon problem involves more than a harmful pollutant of the living spaces of our buildings -- it also involves energy to operate radon removal equipment and the loss of interior conditioned air as a direct result. The techniques used for air infiltration evaluation will be shown to be very useful in dealing with the radon mitigation challenge. 10 refs., 7 figs., 1 tab

  2. BGS Radon Protective Measures GIS

    International Nuclear Information System (INIS)

    Appleton, D.; Adlam, K.

    2000-01-01

    The British Geological Survey Radon Protective Measures Geographical Information System is described. The following issues are highlighted: Identification of development sites where radon protection is required in new dwellings; Mapping radon potential on the basis of house radon and geology; Radon Protective Measures GIS; Radon site reports; and Follow-up radon protective measures sire reports

  3. Development of 66 kV/6.9 kV 2 MV A prototype HTS power transformer

    International Nuclear Information System (INIS)

    Bohno, T.; Tomioka, A.; Imaizumi, M.; Sanuki, Y.; Yamamoto, T.; Yasukawa, Y.; Ono, H.; Yagi, Y.; Iwadate, K.

    2005-01-01

    We have developed the technology of the producing a HTS magnet for the power transformer. Three subjects have been mainly studied, high voltage technologies, large current and low AC loss technologies and sub-cooling system technologies to establish the technology of 66 kV/6.9 kV 10 MV A class HTS power transformer. In order to verify the validity of elemental technologies, such as high voltage technologies, large current and low AC loss technologies and sub-cooling system technologies, single-phase 2 MV A class 66 kV/6.9 kV prototype HTS transformer was manufactured and tested. In the load loss (AC loss) measurement, it was obtained that the measured value of 633 W was almost corresponding to the calculated value of 576 W at the rated operation of 2 MV A. Moreover, the breakdown was not found all voltage withstand test. These test results indicate that elemental technologies were established for the development of 66 kV/6.9 kV 10 MV A class HTS power transformer

  4. On the interaction between radon progeny and particles generated by electronic and traditional cigarettes

    Science.gov (United States)

    Vargas Trassierra, C.; Cardellini, F.; Buonanno, G.; De Felice, P.

    2015-04-01

    During their entire lives, people are exposed to the pollutants present in indoor air. Recently, Electronic Nicotine Delivery Systems, mainly known as electronic cigarettes, have been widely commercialized: they deliver particles into the lungs of the users but a "second-hand smoke" has yet to be associated to this indoor source. On the other hand, the naturally-occurring radioactive gas, i.e. radon, represents a significant risk for lung cancer, and the cumulative action of these two agents could be worse than the agents separately would. In order to deepen the interaction between radon progeny and second-hand aerosol from different types of cigarettes, a designed experimental study was carried out by generating aerosol from e-cigarette vaping as well as from second-hand traditional smoke inside a walk-in radon chamber at the National Institute of Ionizing Radiation Metrology (INMRI) of Italy. In this chamber, the radon present in air comes naturally from the floor and ambient conditions are controlled. To characterize the sidestream smoke emitted by cigarettes, condensation particle counters and scanning mobility particle sizer were used. Radon concentration in the air was measured through an Alphaguard ionization chamber, whereas the measurement of radon decay product in the air was performed with the Tracelab BWLM Plus-2S Radon daughter Monitor. It was found an increase of the Potential Alpha-Energy Concentration (PAEC) due to the radon decay products attached to aerosol for higher particle number concentrations. This varied from 7.47 ± 0.34 MeV L-1 to 12.6 ± 0.26 MeV L-1 (69%) for the e-cigarette. In the case of traditional cigarette and at the same radon concentration, the increase was from 14.1 ± 0.43 MeV L-1 to 18.6 ± 0.19 MeV L-1 (31%). The equilibrium factor increases, varying from 23.4% ± 1.11% to 29.5% ± 0.26% and from 30.9% ± 1.0% to 38.1 ± 0.88 for the e-cigarette and traditional cigarette, respectively. These growths still continue for long

  5. Summary of EPA's radon-reduction research in schools during 1989-90

    International Nuclear Information System (INIS)

    Leovic, K.W.

    1990-10-01

    The report details radon mitigation research in schools conducted by EPA during 1989 and part of 1990. The major objective was to evaluate the potential of active subslab depressurization (ASD) in various geologic and climatic regions. The different geographic regions also presented a variety of construction types and heating, ventilating, and air-conditioning (HVAC) system designs that are encountered in radon mitigation of school buildings. A secondary objective was to initiate research in difficult-to-mitigate schools. The research led to the following major conclusions on radon diagnostics and mitigation in schools: (1) Schools have many physical characteristics that typically make their mitigation more complex than house mitigation, including building size and substructure, subslab barriers, HVAC systems, and locations of utility lines. (2) Important school diagnostic procedures and measurements include review of radon measurements and building plans, investigation of the building to assess potential radon entry routes and confirm information in the building plans, analysis of the HVAC system and its influence on pressure differentials and radon levels, and subslab pressure field extension measurements to determine the potential applicability of ASD. (3) ASD can be applied successfully in schools where subslab communication barriers are limited

  6. Treatment of radon rich well water

    International Nuclear Information System (INIS)

    Mose, D.; Mushrush, G.; Chrosniak, C.

    1991-01-01

    Private wells supply potable water to about 25% of the homes in northern Virginia, and almost all water wells contain radon, a carcinogenic radionuclide derived form uranium in rocks and soil. The average Virginia well provides about 2,000-3,000 pCi/l of dissolved radon; the US Environmental Protection Agency has proposed that 300 pCi/l of should be the allowed maximum for public water supplies. To estimate the ability of activated charcoal to remove radon from private well water, a home supplied by a water well carrying at sign 4,000 pCi/l was studied. Following 1 year of water measurements, an in-line tank containing 1 cubic foot of activated charcoal was installed, and a subsequent 6 month interval of radon measurements on untreated and on treated water was conducted. Although removal rates of more than 90% have been reported, this study home showed a 60-70% radiation removal in the tank. A high percentage removal rate was reached in less than a month after installation, and was maintained for about 4 months, but the removal rate declined to about 50% by the end of the testing interval. Additional studies are being conducted to determine the effect of using different charcoal volumes, different charcoal types; also being studied is the gamma emission of the charcoal tank

  7. Response of Radon in a seismic calibration explosion, Israel

    International Nuclear Information System (INIS)

    Zafrir, H.; Steinitz, G.; Malik, U.; Haquin, G.; Gazit-Yaari, N.

    2009-01-01

    Radon measurements were performed at shallow levels during an in-land 20-ton seismic calibration explosion experiment, simulating a 2.6-M L earthquake, to investigate the influence of the explosive blast and the transitory seismic wave fields on the Radon transport in the country rock, adjacent to the focus of the explosion. The experiment was conducted in a basalt quarry in the northern margin of the Beit Shean valley (Israel). Five gamma-ray sensors were placed, at a depth of about 2 m, along a line located 17-150 m from the edge of the explosion zone. Measurements commenced 4 days before and continued for 9 days after the explosion with 15 min integrations. A 10-s sampling was used in the interval of several hours before and after the explosion itself. Diurnal variations of Radon, reflecting the typical variation pattern of Radon in the shallow environment, were registered before and after the explosion. No significant change in the overall Radon concentration was observed as a consequence of the main explosion as well as three smaller experimental shots (0.5-2 tons) in the 2 h prior to the calibration blast. The seismological data indicate that the transient excess pressure at the farthest Radon sensor was above 5 bar m -1 during 0.2-0.4 s, and evidently much higher at the nearest sensors, but none of the sensors responded by recording any exceptional change in the Radon concentration. Moreover the hypothesis that additional Radon may emanate from solid grains as a result of the excess local pressure exerted by the blast is also not observed. In contrast to a real earthquake event an explosion experiment has neither eventual preceding nor following geodynamic activity. Therefore the absence of significant Radon anomalies during or after the blast does not contradict assumptions, observations or conclusions as the occurrence of Radon anomalies prior or after an earthquake event due to associated long-term geodynamic processes.

  8. Radon Measurements in Vojvodina

    International Nuclear Information System (INIS)

    Bikit, I.; Bikit, K.; Forkapic, S.; Mrda, D.; Nikolov, J.; Todorovic, N.; Veskovic, M.

    2013-01-01

    Recent analyses of epidemiological studies of lung cancer risk from residential exposures demonstrate a statistically significant increase per unit of exposure below average annual concentrations of about 200 Bq/m 3 . Indoor radon measurements performed in Novi Sad in about 400 houses and flats are presented and discussed in this paper. By measuring gamma-activity of radon daughters, radon activity concentration was determined to be 50 Bq/m 3 . In Vojvodina region indoor radon levels were measured by alpha track detectors CR-39 on about 3000 locations during the winter seasons in the period of three years (2003-2005). The main aim of the present study was to explore the critical group of population for radon exposure and to estimate maximal annual doses. Existing radon maps which identify regions with elevated radon levels will improve data collection and analysis for the future radon campaigns. Collaboration on the JRC program of European indoor radon map and implementation of grid system are also discussed.(author)

  9. Radon and cancer

    International Nuclear Information System (INIS)

    2011-01-01

    This publication proposes an overview on what is known about the carcinogenic effect of radon. It recalls the origin of radon, its presence in the environment, and its radioactivity. It comments data on the relationship between exposure to radon and lung cancer, and with other forms of cancer. It discusses the role of the exposure level, and the cases of professional and domestic exposure with respect to these risks. It indicates the hazardous areas in France which are well identified, outlines that smokers are more likely victims of risks related to radon, that this risk is still underrated and underestimated (notably by the public). It gives an overview of existing regulations regarding exposure to radon, of public health policies and national plans concerning radon, and recalls some WHO recommendations

  10. Radon awareness in Ireland: a assessment of the effectiveness of radon road shows

    International Nuclear Information System (INIS)

    Synnott, H.

    2006-01-01

    Full text: In late 2004 the Radiological Protection Institute of Ireland (R.P.I.I.) initiated a series of radon road shows in areas designated as High Radon Areas 1 in the R.P.I.I. s national radon survey of homes. The main objective of these road shows was to provide information to a local audience on the risks of exposure to radon. These road shows target both employers and householders. Each road show has the same general format. A presentation and/or meeting with a major employer representative group within the area. The purpose is to make employers aware of the risks associated with exposure to radon in the workplace and to highlight their obligations under current Irish health and safety legislation regarding radon in the workplace. An information stand on radon manned by R.P.I.I. staff members in a local shopping centre or other similar area. This provides those concerned about radon with accessible information on radon exposure risks, how to measure radon and the steps a home owner could take to reduce radon concentrations where necessary. Where possible R.P.I.I. staff members visit one or more schools in the general area. A short presentation on radon was given to students and students were given an opportunity to asks questions Maximizing media exposure to publicize our visits is vital to the success of these visits. Each visit is preceded by a Press Release whose main aim is to brief local and national media on the radon issue so as to achieve maximum publicity mainly through radio and television coverage. In general the media are very interested in the whole radon area and R.P.I.I. staff members have given 57 radio and 10 television interviews to date since the commencement of this initiative. The four road shows carried out to date have been successful in encouraging householders to carry out radon measurements. Since the start of the road shows to the present, the R.P.I.I. has seen a 44% increase in the number of householders requesting radon

  11. 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.)

  12. GENETIC TRANSFORMATION AND ANALYSIS OF WHEAT TRANSGENIC CELL LINES BY IRAP-PCR

    Directory of Open Access Journals (Sweden)

    Bavol A. V.

    2013-12-01

    Full Text Available The transgenic wheat cell lines were obtained via biolistic transformation of the callus cultures initiated from the 3-day-old sterile seedling shoot apexes. The pAHC25 vector construction used for 14- and 28-day-old callus cultures transformation carried the selective phosphinothricin-N-acetyltransferase (bar gene and reporter ?-glucuronidase gene. The cell line selection was carried out on the media with phosphinothricin by means of graduated cell selection. The transgenic status of the obtained forms was proved by PCR-analysis. The presence of new relatively high molecular (more than 1 000 bp amplicons were found out for three transformed lines by means of IRAP PCRanalysis with the primers coding for long termainal repeats sequences of SIRE 1 retrotransposon. This fact may prove transposition of this mobile genetic element. The new DNA fragments were detected for three of the seven analyzed lines but for the control callus. It is possible to assume at induction of SIRE 1 transposition bis probably caused by the genomic stress of foreign DNA inserting or associated with the transformation process (mechanical wounding, cultivation on selective media.

  13. Radon: A special case in radiation protection

    International Nuclear Information System (INIS)

    Vanmarcke, H.

    2008-01-01

    The conversion conventions of ICRP 65 are based on equality of detriment, not on dosimetry. They are derived from epidemiological studies on miners by comparing the risk of having fatal lung cancer with the detriment associated with a unit of exposure in ICRP 60. Things have moved on since ICRP 65 and the new scientific evidence (numerator change, denominator change and also the dosimetric approach in ICRP 66) is pointing away from ICRP 65 in the direction of the long-established UNSCEAR conversion factor of 9 (nSv h -1 )/(Bq m -3 ) radon progeny exposure, which is 50% higher than the ICRP 65 conversion convention for members of the public. Anyhow, smoking, by the almost multiplicative relationship with radon, determines to a considerable extent the lung cancer risk. Although there is a fairly general consensus among health physicists that radon exposure constitutes the largest and most variable contribution to the population exposure from natural sources, they are divided between themselves on the numerical value of the risk estimates and on the need and urgency to incite the population to take action. This relaxed attitude to radon exposure is reflected in the regulatory approach, which is very much in line with the perceived risk by the population. (authors)

  14. Development of in-situ radon sensor using plastic scintillator

    International Nuclear Information System (INIS)

    Shitashima, Kiminori

    2009-01-01

    Underwater in-situ radon measurement is important scientific priority for oceanography, especially for survey and monitoring of submarine groundwater discharge (SDG). The high sensitivity and lightweight underwater in-situ radon sensor using NaI(Tl) doped plastic scintillator was developed for application to SDG research. Because NaI(Tl) doped plastic scintillator contacts seawater directly, the plastic scintillator can expect high sensitivity in comparison with NaI(Tl) crystal sealed in a container. In order to improve condensation efficiency of scintillation, the plastic scintillator was processed in funnel form and coated by light-resistant paint. This sensor consists of plastic scintillator, photomultiplier tube, preamplifier unit, high-voltage power supply, data logger and lithium-ion battery, and all parts are stored in a pressure housing (200φx300L). The newly developed underwater in-situ radon sensor was tested at hydrothermal area (underwater hot springs) that the hydrothermal fluid containing high concentration of radon is discharged into seawater. The sensor was operated by a diver, and sensitivity tests and mapping survey for estimation of radon diffusion were carried out. The signals of the radon sensor ranged from 20 to 65 mV, and these signals corresponded with radon concentration of 2 to 12 becquerels per liter. The sensor was able to detect radon to 20 m above the hydrothermal point (seafloor). Since the sensor is small and light-weight, measurement, monitoring and mapping can perform automatically by installing the sensor to an AUV (autonomous underwater vehicle). Furthermore, underwater in-situ radon sensor is expected an application to earthquake prediction and volcanic activity monitoring as well as oceanography and hydrology. (author)

  15. Wigner distribution and fractional Fourier transform

    NARCIS (Netherlands)

    Alieva, T.; Bastiaans, M.J.

    2001-01-01

    The connection between the Wigner distribution and the squared modulus of the fractional Fourier transform - which are both well-known time-frequency representations of a signal - is established. In particular the Radon-Wigner transform is used, which relates projections of the Wigner distribution

  16. Relationships between radon anomalies and seismic parameters in N-W Himalaya, India

    International Nuclear Information System (INIS)

    Walia, Vivek; Virk, H.S.; Bajwa, B.S.; Sharma, Navjeet

    2003-01-01

    Radon data accumulated during 1992-1999 in the grid (30-34 deg. N, 74-78 deg. E) in N-W Himalaya have been anlaysed vis a vis seismic data recorded in the same area, supplied by Indian Meteorological Department (IMD) network. In general, there is a positive correlation between the total radon emission and the microseismicity in the area under investigation. The earthquake magnitude has moderate positive correlation with epicentral distance and low positive correlation with amplitude of radon precursory signal, whereas both show low negative correlation between them. Empirical scaling relations are proposed using the best fit straight line from the log-linear graphs between magnitude of the events and log of the product of amplitude of radon anomaly and epicentral distance. The error between the recorded and calculated magnitude is also taken into account. The error range is higher at lower epicentral distances and magnitudes, showing that the local geology and tectonics have predominant influence on radon signals

  17. 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)

  18. Predictors of Indoor Radon Concentrations in Pennsylvania, 1989–2013

    Science.gov (United States)

    Casey, Joan A.; Ogburn, Elizabeth L.; Rasmussen, Sara G.; Irving, Jennifer K.; Pollak, Jonathan; Locke, Paul A.

    2015-01-01

    Background Radon is the second-leading cause of lung cancer worldwide. Most indoor exposure occurs by diffusion of soil gas. Radon is also found in well water, natural gas, and ambient air. Pennsylvania has high indoor radon concentrations; buildings are often tested during real estate transactions, with results reported to the Department of Environmental Protection (PADEP). Objectives We evaluated predictors of indoor radon concentrations. Methods Using first-floor and basement indoor radon results reported to the PADEP between 1987 and 2013, we evaluated associations of radon concentrations (natural log transformed) with geology, water source, building characteristics, season, weather, community socioeconomic status, community type, and unconventional natural gas development measures based on drilled and producing wells. Results Primary analysis included 866,735 first measurements by building, with the large majority from homes. The geologic rock layer on which the building sat was strongly associated with radon concentration (e.g., Axemann Formation, median = 365 Bq/m3, IQR = 167–679 vs. Stockton Formation, median = 93 Bq/m3, IQR = 52–178). In adjusted analysis, buildings using well water had 21% higher concentrations (β = 0.191, 95% CI: 0.184, 0.198). Buildings in cities (vs. townships) had lower concentrations (β = –0.323, 95% CI: –0.333, –0.314). When we included multiple tests per building, concentrations declined with repeated measurements over time. Between 2005 and 2013, 7,469 unconventional wells were drilled in Pennsylvania. Basement radon concentrations fluctuated between 1987 and 2003, but began an upward trend from 2004 to 2012 in all county categories (p Pennsylvania, 1989–2013. Environ Health Perspect 123:1130–1137; http://dx.doi.org/10.1289/ehp.1409014 PMID:25856050

  19. 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

  20. Reasons for increasing radon concentrations in radon remediated houses

    International Nuclear Information System (INIS)

    Clavensjoe, B.

    1997-01-01

    The study comprises 31 single-dwelling houses where remedial actions were carried out in the 1980s. In all of them the radon concentrations have increased more than 30% according to recent control measurements. Radon sources are building material as well as the soil. The remedial actions dealt with ventilation systems, leakage through the basement floor, air cushions, sub-slab suction or radon wells according to the original problems. Causes for the increase varied: In many houses with soil radon problems, the installation of a normal mechanical ventilation system is not a good remedial action. In some houses on a ground with high permeability and high radon content in the soil air, the radon concentration may increase by the lowering of the indoor air pressure. In other houses the increase was a measurement effect, where sites/rooms were confused. Living related causes were identified in a number of cases, where fan speeds were reduced for energy conservation/noise reduction purposes or different use of windows airing had occurred. Extension of the dwelling space without changing the ventilation system caused the increase in one house. 23 refs

  1. The optimation of radon-222 determination in water by Lucas cell technique

    International Nuclear Information System (INIS)

    Andrejkovicova, S.; Kuruc, J.; Kovacsova, A.; Mackova, J.; Rajec, P.

    2003-01-01

    The aim of this work was to determine detection efficiency ε, volume activity a v , low detection limit, minimal detection activity for radon. There were collecting several samples of water: water from tap water, mineral water, thermal water, water from wells and bottled drinking water. As we expected, the lowest values of volume activities of radon were reached in bottled drinking water (0.1 - 4.9 Bq/dm 3 ). Higher values were reached in water from tap water and natural mineral water (2.5 - 14.9 Bq/dm 3 ). The highest volume activities of radon were obtained in thermal water and water from wells (17.2 - 107.9 Bq/dm 3 ). Method for determination of radon in water was verified at Institute of Preventive and Clinical Medicine, Bratislava, Slovakia. Results of radon concentration in waters are in accordance with an uppermost - accepted value of radon in water. The volume activity of radon in our samples has never been higher as a limit value has allowed (300 Bq/dm 3 ). (authors)

  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. Studies on radon concentration in underground water samples in and around Kabini river basin

    International Nuclear Information System (INIS)

    Yashaswini, T.; Ningappa, C.; Niranjan, R.S.; Sannappa, J.

    2017-01-01

    Radon is a radioactive inert gas, a decay product of radium, causes environmental health problems like lung cancer. Radium present in the earth crest continuously releases radon into underground water. From the point view of health, the study of radon concentration level in underground water base line data is important. In the present study, radon concentration in underground water have been measured in 40 underground water samples collected in and around Kabini River of Karnataka State by using Emanometry technique. The radon concentration in the study area varies from 21.2 to 168.2Bq.l -1 with a geometrical mean value of 73.3 Bq.l -1 . The physicochemical parameters of water such as chloride, Fluoride, nitrite, sulphate, TDS are measured in the same samples in order to know about the impact of these parameters on radon concentration and their health risks to the general public. The experimental techniques and results obtained are discussed in the presentation. (author)

  4. Instruments to measure radon-222 activity concentration or exposure to radon-222. Intercomparison 2014

    International Nuclear Information System (INIS)

    Foerster, Elisabeth; Beck, Thomas; Buchroeder, Helmut; Doering, Joachim; Schmidt, Volkmar

    2014-10-01

    According to the Directive 96/29/EURATOM the monitoring of occupational radiation exposures shall base on individual measurements carried out by an approved dosimetric service. Pursuant to the European Directive an approved dosimetric service is a body responsible for the calibration, reading or interpretation of individual monitoring devices.., whose capacity to act in this respect is recognized by the competent authorities. This concept will also be applied to radon services issuing passive radon measurement devices. Passive radon measurement devices 1 using solid state nuclear track detectors or electrets are recommended for individual monitoring of exposures to radon. German regulations lay down that radon measuring devices are appropriate for purposes of occupational radiation monitoring if the devices are issued by recognized radon measurement services, and the measurement service submits devices of the same type issued for radon monitoring to regular intercomparisons conducted by the Bundesamt fuer Strahlenschutz (BfS). A radon measuring service is recognized by the competent authority if it proves its organisational and technical competence, e. g. by accreditation. These regulations have been introduced in the area of occupational radiation exposures. Nevertheless, it is recommended that radon measuring services which carry out radon measurements in other areas (e.g. dwellings) should subject themselves to these measures voluntarily. The interlaboratory comparisons comprise the organization, exposure, and evaluation of measurements of radon activity concentration or exposure to radon. The comparisons only concern radon-222; radon-220 is not in the scope. Radon services being interested can get further information from the European Information System on Proficiency Testing Schemes (EPTIS) and from the BfS websites.

  5. Radon in workplaces

    International Nuclear Information System (INIS)

    Reichelt, A.; Lehmann, K.-H.; Reineking, A.; Porstendoerfer, J.; Schwedt, J.; Streil, T.

    2000-01-01

    The radiological assessment of the results of radon measurements in dwellings is not automatically applicable to workplaces due to different forms of utilization, constructional conditions, time of exposure, heating and ventilation conditions, additional aerosol sources, aerosol parameters, chemical substances, etc. In order to investigate the peculiarities of the radon situation in workplaces located inside buildings compared with that in dwellings, long-time recordings of radon, attached radon progeny and unattached radon progeny concentrations ( 218 Po, 214 Pb, 214 Bi) are carried out at several categories of workplaces (e.g. offices, social establishments, schools, production rooms, workshops, kitchens, agricultural facilities). 36 workplaces have been investigated. There have been carried out at least 2-3 long-time recordings for each workplace during different seasons. At the same time the gamma dose rate, meteorological conditions, aerosol particle concentrations have been registered. Many special dates from the workplaces and the buildings have been recorded. Activity size distribution of the aerosol-attached and unattached fraction of short-lived radon decay products have been determinated in 20 workplaces. Mainly the following measurement systems were used: Radon- and Radon Progeny Monitor EQF 3020, SARAD GmbH, Germany. Alpha-Track Radon Detectors, BfS Berlin, Germany. Screen Diffusion Batteries with Different Screens, University of Goettingen, Germany. Low-Pressure Cascade Impactor, Type BERNER. Condensation Nuclei Counter, General Electric, USA. PAEC-f p -Rn-Monitor, University of Goettingen, Germany. Through the measurements, many peculiarities in the course of the radon-concentration, the equilibrium factor F, the unattached fraction f p and the activity size distribution have been determined. These amounts are influenced mainly by the working conditions and the working intervals. The influence of these peculiarities in workplaces on the dose have

  6. 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

  7. 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

  8. 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

  9. 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

  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 in Estonian dwellings - Results from a National Radon Survey

    Energy Technology Data Exchange (ETDEWEB)

    Pahapill, Lia; Rulkov, Anne; Rajamaee, Raivo [Estonian Radiation Protection Centre (Kiirguskeskus), Tallinn (Spain); Aakerblom, Gustav [Swedish Radiation Protection Authority, Stockholm (Sweden)

    2003-10-01

    A countrywide survey of radon concentrations in Estonian dwellings was carried out during the period 1998-2001. The survey formed a part of the cooperation program on radiation protection between the Estonian Radiation Protection (Kiirguskeskus) Centre and the Swedish Radiation Protection Authority (SSI). The survey included measurements in a number of dwellings representative for Estonia in detached houses and multifamily buildings (only dwellings on the bottom floor were included in the survey). Altogether, radon concentrations were measured in 515 dwellings, a number large enough to be statistically significant. All measurements were made with alphatrack film detectors of the same type that SSI uses in Sweden. The measurements were made during a 2-3 month period during the winter half-year. Two detectors were used in each dwelling. In Estonia there are 0.17 million dwellings in detached houses and 0.45 million in multi apartment buildings. Of the 1.26 million inhabitants in Estonia. 0.36 million live in detached houses and 0.90 million in multi apartment buildings. Most of the latter were built during the Soviet occupation. Of the dwellings in multifamily buildings 30 % are assumed to be situated on the first floor. The mean radon concentration in dwellings in detached hoses, according to the survey results, is 103 Bq/m{sup 3}, in dwellings on the bottom floor in multi apartment buildings it is 78 Bq/m{sup 3}. In 1% of the dwellings the radon concentration exceeded 400 Bq/m{sup 3}. The highest radon concentration found in the study was 1040 Bq/m{sup 3}. Based on the assumption that the average radon concentration in the dwellings in multi-apartment buildings that are not situated on the bottom floor is 30 Bq/m{sup 3}, and that these dwellings constitute 70% of all dwellings in multi apartment buildings, the mean radon concentration in dwellings in multi apartment buildings is calculated to be 44 Bq/m{sup 3}. The mean value for all Estonia dwellings is calculated

  12. Radon in Estonian dwellings - Results from a National Radon Survey

    International Nuclear Information System (INIS)

    Pahapill, Lia; Rulkov, Anne; Rajamaee, Raivo; Aakerblom, Gustav

    2003-10-01

    A countrywide survey of radon concentrations in Estonian dwellings was carried out during the period 1998-2001. The survey formed a part of the cooperation program on radiation protection between the Estonian Radiation Protection (Kiirguskeskus) Centre and the Swedish Radiation Protection Authority (SSI). The survey included measurements in a number of dwellings representative for Estonia in detached houses and multifamily buildings (only dwellings on the bottom floor were included in the survey). Altogether, radon concentrations were measured in 515 dwellings, a number large enough to be statistically significant. All measurements were made with alphatrack film detectors of the same type that SSI uses in Sweden. The measurements were made during a 2-3 month period during the winter half-year. Two detectors were used in each dwelling. In Estonia there are 0.17 million dwellings in detached houses and 0.45 million in multi apartment buildings. Of the 1.26 million inhabitants in Estonia. 0.36 million live in detached houses and 0.90 million in multi apartment buildings. Most of the latter were built during the Soviet occupation. Of the dwellings in multifamily buildings 30 % are assumed to be situated on the first floor. The mean radon concentration in dwellings in detached hoses, according to the survey results, is 103 Bq/m 3 , in dwellings on the bottom floor in multi apartment buildings it is 78 Bq/m 3 . In 1% of the dwellings the radon concentration exceeded 400 Bq/m 3 . The highest radon concentration found in the study was 1040 Bq/m 3 . Based on the assumption that the average radon concentration in the dwellings in multi-apartment buildings that are not situated on the bottom floor is 30 Bq/m 3 , and that these dwellings constitute 70% of all dwellings in multi apartment buildings, the mean radon concentration in dwellings in multi apartment buildings is calculated to be 44 Bq/m 3 . The mean value for all Estonia dwellings is calculated to be 60 Bq/m 3 . Using

  13. Radon-film-badges by solid radiators to complement track detector-based radon monitors

    International Nuclear Information System (INIS)

    Tommasino, L.; Tommasino, M.C.; Viola, P.

    2009-01-01

    Existing passive radon monitors, based on track detectors, present many shortcomings, such as a limited response sensitivity for one-week-indoor measurements and a limited response linearity for the assessment of large radon exposures indoors, in thermal spa, in caves, and in soil. Moreover, for in-soil measurements these monitors are too bulky and are often conducive to wrong results. For what concerns the radon-in-water measurements, they are just not suitable. A new generation of passive radon monitors is introduced in this paper, which are very similar to the compact badges used in neutron- and gamma-dosimetry and will be referred to as radon-film-badges. These film-badges are formed by thin-film radiators with suitable radon-sorption characteristics, facing track detectors. The key strategy adopted for these radiators is to exploit an equilibrium type of radon sorption in solids. Even though this new generation of passive monitors is at its infancy, it appears already clear that said monitors make it finally possible to overcome most of the shortcomings of existing passive radon monitors. These devices are uniquely simple and can be easily acquired by any existing radon service to complement their presently used passive radon monitors with little or no effort.

  14. Radon in buildings

    International Nuclear Information System (INIS)

    Connell, J.J.

    1991-01-01

    This guide is intended to inform designers, householders and other building owners about the radon problem and to help in deciding if there is need to take any action to reduce radon levels in their homes or other buildings.It explains what radon is, how it enters buildings and what effect it may have on health. Reference is made to some of the usual ways of reducing the level of radon and guidance is given on some sources of assistance

  15. Radon and its hazards

    International Nuclear Information System (INIS)

    Chang Guilan

    2002-01-01

    The author describes basic physical and chemical properties of radon and the emanation, introduces methods of radon measurement, expounds the hazards of non-mine radon accumulation to the health of human being and the protection, as well as the history how the human being recognizes the hazards of radon through the specific data and examples, and finally proposes protecting measures to avoid the hazards of radon to the health of human being, and to do ecologic evaluation of environments

  16. Radon daughter control in the Uravan Mineral Belt

    International Nuclear Information System (INIS)

    Swindle, R.W.

    1977-01-01

    The control of radon daughter products in mines of the Uravan Mineral Belt is strongly affected by the erratic nature of the ore deposits. Another problem is the frequent necessity of reactivating mine workings that have been inactive for many years. Ventilation holes and other airways are usually too small to provide adequate ventilation to satisfy current requirements, and they are often caved. The greatest change in ventilation systems in recent years has been the trend toward larger-diameter, drilled ventilation raises that provide more ventilation at considerably lower cost. The increase in raise size has aggrevated ground-support and ice-formation, difficulties, but these problems are being solved by lining the raises with shotcrete and grouting the water bearing horizons. Electronic air cleaners have been effectively used to remove radon daughter products from mine air for several years but their utility is limited by the rate of regrowth of the radon daughters after the air is cleaned. 5 figures

  17. 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

  18. Human perception of radon risk and radon mitigation: Some remarks

    International Nuclear Information System (INIS)

    Neznal, M.; Neznal, M.

    2008-01-01

    The Radon program in the Czech Republic has a relatively long and rich history. Procedures, which enable to evaluate the risk of radon penetration from the ground, to protect new buildings, to find existing buildings with elevated indoor radon levels and to realise remedial measures in such buildings, have been developed, published and tested. In some cases, the whole system may fail due to psychological or sociological reasons. Three types of problems (conflicts) will be presented: human behaviour affecting measurement results, conflict between individual and 'all-society' points of view, interpretation of radon risk itself. (authors)

  19. Radon/radon-daughter measurement methods and instrumentation

    International Nuclear Information System (INIS)

    Rock, R.L.

    1977-01-01

    Radon-daughter measurement equipment and techniques have been continuously improved over the last 25 years. Improvements have been in the areas of accuracy, time and convenience. We now have miniaturized scalers and detectors available for measuring the alpha particle count rates from aerosol samples collected on filter papers. We also have small lightweight efficient pumps for conveniently collecting samples and we have various counting methods which allow us to choose between making very precise measurements or nominal measurements. Radon-daughter measurement methods used in uranium mines and mills are discussed including a personal radon-daughter-exposure integrating device which can be worn by miners

  20. Development of a PIN diode based on-line measurement system for Radon (222Rn) and Thoron (220Rn) in environment

    International Nuclear Information System (INIS)

    Ashokkumar, P.; Chaudhury, Probal; Sumesh, C.G.; Sahoo, B.K.; Gaware, J.J.; Mayya, Y.S.

    2014-01-01

    Radon, thoron and their progenies are universally present in outdoor air, and can reach higher levels in indoor air due to poor ventilation. Several instruments have been developed for accurate measurement of radon and thoron in the environment. Semiconductor detector based system employing spectroscopic method has been proved to be the best among them. A PIN diode based electrostatic collection type online real-time instrument has been developed in Bhabha Atomic Research Centre for simultaneous measurement of radon and thoron in an environment while both 222 Rn and 220 Rn are present. This system can be used for determination of radon and thoron concentrations at residence or workplace. Furthermore, since the 222 Rn and 220 Rn are differentiated from each other through spectroscopy, this monitor can be used even in a mixed radon/thoron environment

  1. Radon level and radon effective dose rate determination in Moroccan dwellings using SSNTDs

    International Nuclear Information System (INIS)

    Oufni, L.; Misdaq, M.A.; Amrane, M.

    2005-01-01

    Inhalation of radon ( 222 Rn) and its daughter product are a major source of natural radiation exposure. The measurement of radon activity in dwelling is assuming ever increasing importance. 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. Keeping this in view, the indoor radon activity level and radon effective dose rate were carried out in the dwellings of Beni-Mellal, Khouribgra and Ben Guerir cities, Morocco, using the solid state nuclear track detectors (SSNTD) technique. Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, we found that the 222 Rn effective dose rate in the studied dwellings ranges from 1.01 to 7.90mSvy -1 . The radon activity in the corresponding dwellings was found to vary from 40 to 532Bqm -3 . The radon activity has not only been found to vary with seasonal changes, but also with the age, the construction mode of houses, the ventilation conditions and with specific sites and geological materials

  2. EML indoor radon workshop, 1982

    International Nuclear Information System (INIS)

    George, A.C.; Lowder, W.; Fisenne, I.; Knutson, E.O.; Hinchliffe, L.

    1983-07-01

    A workshop on indoor radon, held at the Environmental Measurements Laboratory (EML) on November 30 and December 1, 1982, covered recent developments in radon daughter research and development. Thirty papers were presented dealing with standardization and quality assurance measurement methods, surveys, measurements strategy, physical mechanisms of radon and radon daughter transport and development of guidance standards for indoor exposures. The workshop concluded with a planning session that identified the following needs: (1) national and international intercomparisons of techniques for measuring radon and radon daughter concentrations, working level and radon exhalation flux density; (2) development and refinement of practical measurement techniques for thoron and its daughter products; (3) quantitative definition of the sources of indoor radon and the mechanisms of transport into structures; (4) better knowledge of the physical properties of radon daughters; (5) more complete and accurate data on the population exposure to radon, which can only be met by broadly based surveys; and (6) more international cooperation and information exchange among countries with major research programs

  3. 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.

  4. Disturbance from Am-241 Photons of the Cellular Dose by Am-241 Alpha Emissions: Am-241 as an alternative source of alpha particles to radon daughters

    International Nuclear Information System (INIS)

    Lee, Ki-Man; Kim, Eun-Hee

    2015-01-01

    The Radiation Bioengineering Laboratory (RadBio Lab) at Seoul National University (SNU) has built an Am-241 alpha particle irradiator for study of cellular responses to radiation from radon daughters. The radon daughters of concern that cause internal exposure from inhalation of radon-contaminated air are Po-218, Po-214 and Po-210. In their alpha decay schemes, the yields of photon emissions are negligible. Unfortunately, Am-241, the source of alpha irradiator in RadBio Lab, emits photons at every alpha decay while transforming to Np-237 of long half-life. Employing Am-241 as the source simulating radon daughters, therefore, requires that photon emissions from Am-241 be specified in term of dose contribution. In this study, Monte Carlo calculations have been made to characterize dose contributions of Am-241 photon emissions. This study confirms that disturbance from Am-241 photon emissions of the cellular dose by Am-241 alpha emissions is negligible. Dose contamination fraction from photon emissions was 8.02 .. 10 -6 at 25 mm SSD at maximum. Also, note that LET in tissue-equivalent medium varies within about 20% for alpha particles at energies over 5 MeV

  5. Radon therapy; Radon in der Therapie

    Energy Technology Data Exchange (ETDEWEB)

    Spruck, Kaija [Technische Hochschule Mittelhessen, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz

    2017-04-01

    Radon therapies are used since more than 100 years in human medicine. Today this method is controversially discussed due to the possible increase of ionizing radiation induced tumor risk. Although the exact mode of biological radiation effect on the cell level is still not known new studies show the efficiency of the radon therapy without side effect for instance for rheumatic/inflammatory or respiratory disorders.

  6. 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)

  7. Radon atlas of Finland

    International Nuclear Information System (INIS)

    Voutilainen, A.; Maekelaeinen, I.; Pennanen, M.; Reisbacka, H.; Castren, O.

    1997-11-01

    The most efficient means of reducing indoor radon exposure is to locate and mitigate dwellings with radon concentration exceeding the action level of 400 Bq/m 3 and to build new houses so that radon concentrations do not exceed 200 Bq/m 3 . The maps and tables in this report are useful tools for those who plan and decide what kind of radon mitigation measures are needed in municipalities. STUK (The Radiation and Nuclear Safety Authority) has an indoor radon database of 52 000 dwellings, for which the indoor radon concentration and construction details are known. The building site soil type of about 38 000 dwellings is known. This atlas is a summary of all indoor radon measurements made by STUK in lowrise dwellings and in first-floor flats. The results are shown as arithmetic means of 5- or 10-km squares on maps of the provinces. Three radon maps have been made for each province. On one map the data consist of all measurements the position coordinates of which are known. On the two other maps the building sites of houses are classified into permeable and low-permeable soil types. The tables show statistics for all indoor radon measurements by municipality and building site soil type. (orig.)

  8. 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

  9. The influence of mechanical vibrations of railway and car traffics on the radon exhalation using track detector technique

    International Nuclear Information System (INIS)

    Moharram, B.M.

    2000-01-01

    The influence of train and car traffic vibrations on the radon concentration (CRn) increase near the railway tracks and the heavy traffic roads. It was estimated along the railway road, and perpendicular directions using CR-39 detectors. The special radius of the influence is about 32 m, while the related value for car traffics is found to be about 25 m. The base line of radon concentration in soil gas and radon exhalation are estimated in the whole area, far from the center of traffic roads by a distance (> 100 m) in different different directions and found to be 0.6 Bq/L and 1.25 x 10 4 Bq m -2 respectively.It is easy to detect that the average ratio between the radon concentration at its higher level and its base line, which is regular concentration of radon in the ordinary positions far from the effect of traffics, is about 1.18 for railway traffics. While the related value to vehicle traffic is about 1.23, which is higher than that of railway traffic because the ground is stimulated per minutely

  10. Probabilistic neural network algorithm for using radon emanations as an earthquake precursor

    International Nuclear Information System (INIS)

    Gupta, Dhawal; Shahani, D.T.

    2014-01-01

    The investigation throughout the world in past two decades provides evidence which indicate that significance variation of radon and other soil gases occur in association with major geophysical events such as earthquake. The traditional statistical algorithm includes regression to remove the effect of the meteorological parameters from the raw radon and anomalies are calculated either taking the periodicity in seasonal variations or periodicity computed using Fast Fourier Transform. In case of neural networks the regression step is avoided. A neural network model can be found which can learn the behavior of radon with respect to meteorological parameter in order that changing emission patterns may be adapted to by the model on its own. The output of this neural model is the estimated radon values. This estimated radon value is used to decide whether anomalous behavior of radon has occurred and a valid precursor may be identified. The neural network model developed using Radial Basis function network gave a prediction rate of 87.7%. The same was accompanied by huge false alarms. The present paper deals with improved neural network algorithm using Probabilistic Neural Networks that requires neither an explicit step of regression nor use of any specific period. This neural network model reduces the false alarms to zero and gave same prediction rate as RBF networks. (author)

  11. A distributed parameter model of transmission line transformer for high voltage nanosecond pulse generation.

    Science.gov (United States)

    Li, Jiangtao; Zhao, Zheng; Li, Longjie; He, Jiaxin; Li, Chenjie; Wang, Yifeng; Su, Can

    2017-09-01

    A transmission line transformer has potential advantages for nanosecond pulse generation including excellent frequency response and no leakage inductance. The wave propagation process in a secondary mode line is indispensable due to an obvious inside transient electromagnetic transition in this scenario. The equivalent model of the transmission line transformer is crucial for predicting the output waveform and evaluating the effects of magnetic cores on output performance. However, traditional lumped parameter models are not sufficient for nanosecond pulse generation due to the natural neglect of wave propagations in secondary mode lines based on a lumped parameter assumption. In this paper, a distributed parameter model of transmission line transformer was established to investigate wave propagation in the secondary mode line and its influential factors through theoretical analysis and experimental verification. The wave propagation discontinuity in the secondary mode line induced by magnetic cores is emphasized. Characteristics of the magnetic core under a nanosecond pulse were obtained by experiments. Distribution and formation of the secondary mode current were determined for revealing essential wave propagation processes in secondary mode lines. The output waveform and efficiency were found to be affected dramatically by wave propagation discontinuity in secondary mode lines induced by magnetic cores. The proposed distributed parameter model was proved more suitable for nanosecond pulse generation in aspects of secondary mode current, output efficiency, and output waveform. In depth, comprehension of underlying mechanisms and a broader view of the working principle of the transmission line transformer for nanosecond pulse generation can be obtained through this research.

  12. The effect of natural ventilation on radon and radon progeny levels in houses

    International Nuclear Information System (INIS)

    Cavallo, A.; Gadsby, K.; Reddy, T.A.; Socolow, R.

    1992-01-01

    In contradiction to the widely held assumption that ventilation is ineffective as a means of reducing indoor radon concentrations, experiments in a research house have shown that the basement radon level can be reduced by a factor of 5-10 using only natural ventilation. Measurements of the outdoor-basement pressure differential and the radon entry rate show that this unexpectedly large reduction in indoor radon levels is caused by two complementary physical processes. The first mechanism is the obvious one: dilution. Radon concentrations are lowered by the addition of uncontaminated outdoor air. The second mechanism is less evident: an open basement window reduces basement depressurisation. This decreases the rate at which radon-laden soil gas is drawn into the house. It was also found that the radon entry rate is a linear function of basement depressurisation up to a differential pressure of about 4 Pa, as would be expected for laminar soil gas flow; opening two basement windows approximately doubles the building air exchange rate and reduces the radon entry rate by up to a factor of 5. (author)

  13. Involvement of growth factors and their receptors in radon-induced rat lung tumors

    International Nuclear Information System (INIS)

    Leung, F.C.; Dagle, G.E.; Cross, F.T.

    1992-01-01

    In this paper we examine the role of growth factors (GF) and their receptors (GFR) in radon-induced rat lung tumors. Inhalation exposure of radon and its daughters induced lung tumors in rats, but the molecule/cellular mechanisms are not known. Recent evidence suggests that GF/GFR play a critical role in the growth and development of lung cancer in humans and animals. We have developed immunocytochemical methods for identifying sites of production and action of GF/GFR at the cellular level; for example, the avidin-biotin horseradish peroxidase technique. In radon-induced rat epidermoid carcinomas, epidermal growth factor (EGF), EGF-receptors (EGF-R), transforming growth factor alpha (TGF-α), and bombesin were found to be abnormally expressed. These abnormal expressions, mainly associated with epidermoid carcinomas of the lung, were not found in any other lung tumor types. Our data suggest that EGF, EGF-R, TGF-α, and bombesin are involved in radon oncogenesis in rat lungs, especially in epidermoid carcinomas, possibly through the autocrine/paracrine pathway

  14. Radon og boligen

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    Radon er en radioaktiv og sundhedsskadelig luftart, som ved indånding øger risikoen for lungekræft. Der er ingen dokumenteret nedre grænse for, hvornår radon er ufarligt. Derfor anbefales det, at man tilstræber et så lavt radonindhold i indeluften som muligt. Man kan hverken lugte, se, høre eller...... smage radon, så vil du vide, om du har radon i din bolig, må du måle radonindholdet i indeluften. Radon forekommer naturligt i jorden og kan suges ind sammen med jordluft, hvis der inde er et undertryk, og hvis konstruktionerne mod jord er utætte. Jordluft trænger ind gennem revner og utætte samlinger......, fx omkring rør til kloak, vand og varmeforsyning. Koncentrationen af radon i jorden varierer meget fra sted til sted, også lokalt og gennem året. Tidligere undersøgelser har vist, at der kan forekomme høje koncentrationer i Sydgrønland, specielt i området syd for Narsalik ved Paamiut, 61°30’N....

  15. Radon campaigns. Status report 2008

    International Nuclear Information System (INIS)

    Arvela, H.; Valmari, T.; Reisbacka, H.; Niemelae, H.; Oinas, T.; Maekelaeinen, I.; Laitinen-Sorvari, R.

    2008-12-01

    Radon campaigns aim at activating citizens to make indoor radon measurements and remediation as well as increasing the common awareness of indoor radon questions. Indoor radon increases the risk of lung cancer. Through radon campaigns Radiation and Nuclear Safety Authority (STUK) also promotes the attainment of those goals that the Ministry of Social Affairs and Health has set for municipal authorities in Finland for prevention of the harmful effects of radon. The Ministry of Social Affairs and Health supports this campaign. Radon campaigns were started in autumn 2003. By autumn 2008 the campaigns have been organised already in 64 regions altogether in 160 municipalities. In some municipalities they have already arranged two campaigns. Altogether 14 100 houses have been measured and in 2 100 of these the action limit of radon remediation 400 Bq / m 3 has been exceeded. When participating in radon campaigns the house owners receive a special offer on radon detectors with a reduced price. In 2008 a new practice was introduced where the campaign advertisements were distributed by mail to low-rise residential houses in a certain region. The advertisement includes an order / deposit slip with postage paid that the house owner can send directly to STUK to easily make an order for radon measurement. In the previous radon campaigns in 2003 - 2007 the municipal authorities collected the orders from house owners and distributed later the radon detectors. The radon concentrations measured in the campaign regions have exceeded the action limit of 400 Bq / m 3 in 0 - 39% of houses, depending on the region. The total of 15% of all measurements made exceeded this limit. The remediation activities have been followed by sending a special questionnaire on remedies performed to the house owners. In 2006 - 2007 a questionnaire was sent to those households where the radon concentration of 400 Bq / m 3 was exceeded during the two first campaign seasons. Among the households that replied

  16. 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.

  17. Radon and its daughters in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Rundo, J

    1984-05-01

    Prolonged exposure to radon should build up a reservoir of radon in body fat and fluids. Movement of the subject to an environment with a lower radon concentration from an environment with a higher level of radon would result in an exhalation of radon, and the initial exhalation rate of radon should depend on the radon concentration inhaled. This paper describes the behavior of radon and its daughters in vivo and a relationship between the radon exhalation rate and the time after a meal. A major but short-lived postprandial increase in the exhalation rate of radon was observed. We report a similar effect in the exhalation rate of radon by persons containing no radium. It should be noted that the possibility exists that a large amount of radon daughters in the chest may interfere in the investigation of possible internal contamination with plutonium or other actinides by external counting. (author).

  18. Evaluation and control of radon daughter hazards in uranium mines

    International Nuclear Information System (INIS)

    Holaday, D.A.

    1974-11-01

    This monograph discusses primarily those health hazards to uranium miners which are produced by exposure to ionizing radiation. Emphasis is placed on the areas of evaluation of exposures to the radioactive gas radon-222 and its short-lived transformation products, and methods of controlling such exposures. A limited discussion of the biological effects of radon and radon daughters is undertaken, and some procedures are given for evaluating hazards created by other common contaminants of mine atmospheres. A large amount of information exists on these topics, some of which is unpublished or is not readily available. While efforts were made to obtain data from all sources, undoubtedly some valuable work was overlooked. The monograph is an endeavor to assemble pertinent information and make it available to those who are concerned with producing uranium at minimal risks. Where they were available, a variety of procedures for evaluating hazards are given, and examples of systems for controlling hazards are included. 154 references

  19. Radon in balneology - measurement of radon retention by patients and radiation protection for personell

    International Nuclear Information System (INIS)

    Just, G.; Falkenbach, A.; Grunewald, W.A.; Philipsborn, H. von

    2001-01-01

    In radon balneology patients are exposed to radon either from water or air through the skin or through inhalation. Drinking radon water was not included in the study. Previously, the radon transfer has been determined for an estimate of the medically active amount of radon retained in the patient. A simpler approach of measuring radon in expiration under and after exposure has now been standardised and applied to probands under different conditions of exposure. In addition, radon decay products were measured in sweat, saliva and in the skin. Experimental parameters were evaluated for a comparison of different concentrations observed under different conditions. Results are likely to improve both therapy for patients and radiation protection for members of the personnel. (orig.) [de

  20. 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)

  1. The effect and the amendment of thermoregulation to the stability of radon concentration in radon chamber

    International Nuclear Information System (INIS)

    Zhang Xiongjie; Wang Renbo; Qu Jinhui; Tang Bin; Zhu Zhifu; Man Zaigang

    2010-01-01

    When the temperature in the airtight radon chamber was adjusted, it would induce the frequent changes of the air pressure in chamber, then the radon concentration in the radon chamber would continuously reduce, which could seriously destroy the stability of the radon concentration in radon chamber. In this paper, on the study of the effect reasons to the stability of radon concentration in airtight radon chamber due to the thermoregulation, a new amendment scheme was put forward, and the solutions of the relevant parameters were discussed. The amendment scheme had been successfully applied to HD-6 radon chamber, and achieved good results. (authors)

  2. Rapid determination of radon daughters and of artificial radionuclides in air by online gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Hoetzl, H.; Winkler, R.

    1993-01-01

    For the determination of airborne radionuclide concentrations in real time, a fixed filter device was constructed which fits directly onto a germanium detector with standard nuclear electronics and a multichannel analyzer buffer connected via a data line to a personal computer for remote control and on-line spectrum evaluation. The on-line gamma-ray spectrometer was applied to the study of radon decay product concentrations in ground-level air and to the rapid detection of only contamination of the environmental air by artificial radionuclides. At Munich-Neuherberg, depending on the meteorological conditions, the measured air concentrations of 214 Pb, the first gamma-ray-emitting member of the 222 Rn decay series, varied from about 1 to 50 Bq m -3 . For the artifical radionuclides 60 Co, 131 I and 137 Cs the detection limits were determined as a function of the varying natural radon daughter concentrations at sampling and counting times of 1 h or 1 day. For these radionuclides minimum detectable air activity concentrations of 0.3 or 0.001 Bq m -3 , respectively, were obtained at low radon daughter levels. At high radon daughter levels the respective detection limits were found to be higher by a factor of only about 2. (orig.)

  3. Rapid determination of radon daughters and of artificial radionuclides in air by online gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hoetzl, H.; Winkler, R. (GSF-Forschungszentrum fuer Umwelt und Gesundheit, Neuherberg (Germany). Inst. fuer Strahlenschutz)

    1993-04-01

    For the determination of airborne radionuclide concentrations in real time, a fixed filter device was constructed which fits directly onto a germanium detector with standard nuclear electronics and a multichannel analyzer buffer connected via a data line to a personal computer for remote control and on-line spectrum evaluation. The on-line gamma-ray spectrometer was applied to the study of radon decay product concentrations in ground-level air and to the rapid detection of only contamination of the environmental air by artificial radionuclides. At Munich-Neuherberg, depending on the meteorological conditions, the measured air concentrations of [sup 214]Pb, the first gamma-ray-emitting member of the [sup 222]Rn decay series, varied from about 1 to 50 Bq m[sup -3]. For the artifical radionuclides [sup 60]Co, [sup 131]I and [sup 137]Cs the detection limits were determined as a function of the varying natural radon daughter concentrations at sampling and counting times of 1 h or 1 day. For these radionuclides minimum detectable air activity concentrations of 0.3 or 0.001 Bq m[sup -3], respectively, were obtained at low radon daughter levels. At high radon daughter levels the respective detection limits were found to be higher by a factor of only about 2. (orig.).

  4. 750 keV beam line construction at the KEK

    International Nuclear Information System (INIS)

    Ishimaru, H.; Anami, S.; Inagaki, T.; Sakaue, T.; Itoh, K.; Fukumoto, S.

    1976-01-01

    The construction of 750 keV beam line of the KEK injector of the 12 GeV proton synchrotron was described. The beam line consists of the beam focusing quadrupoles, vacuum system, the electrostatic chopper and the various beam monitors. (author)

  5. 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

  6. 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

  7. Radon and radon daughter monitoring (including thoron daughter monitoring)

    International Nuclear Information System (INIS)

    Leach, V.A.; Grealy, G.; Gan, W.

    1982-01-01

    Radon/radon daughter and thoron daughter measurement techniques are outlined. The necessary precautions and critical assessments of each method are also presented with a view to providing a better understanding of the various measurement methods

  8. Solar eruptions - soil radon - earthquakes

    International Nuclear Information System (INIS)

    Saghatelyan, E.; Petrosyan, L.; Aghbalyan, Yu.; Baburyan, M.; Araratyan, L.

    2004-01-01

    For the first time a new natural phenomenon was established: a contrasting increase in the soil radon level under the influence of solar flares. Such an increase is one of geochemical indicators of earthquakes. Most researchers consider this a phenomenon of exclusively terrestrial processes. Investigations regarding the link of earthquakes to solar activity carried out during the last decade in different countries are based on the analysis of statistical data ΣΕ (t) and W (t). As established, the overall seismicity of the Earth and its separate regions depends of an 11-year long cycle of solar activity. Data provided in the paper based on experimental studies serve the first step on the way of experimental data on revealing cause-and-reason solar-terrestrials bonds in a series s olar eruption-lithosphere radon-earthquakes . They need further collection of experimental data. For the first time, through radon constituent of terrestrial radiation objectification has been made of elementary lattice of the Hartmann's network contoured out by bio location method. As found out, radon concentration variations in Hartmann's network nodes determine the dynamics of solar-terrestrial relationships. Of the three types of rapidly running processes conditioned by solar-terrestrial bonds earthquakes are attributed to rapidly running destructive processes that occur in the most intense way at the juncture of tectonic massifs, along transformed and deep failures. The basic factors provoking the earthquakes are both magnetic-structural effects and a long-term (over 5 months) bombing of the surface of lithosphere by highly energetic particles of corpuscular solar flows, this being approved by photometry. As a result of solar flares that occurred from 29 October to 4 November 2003, a sharply contrasting increase in soil radon was established which is an earthquake indicator on the territory of Yerevan City. A month and a half later, earthquakes occurred in San-Francisco, Iran, Turkey

  9. Uranium prospecting through radon detection; La prospection de l'uranium par le radon

    Energy Technology Data Exchange (ETDEWEB)

    Pradel, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1956-07-01

    Prospecting rests on the determination of the concentration of ground air in radon. Radon diffusing from deep uranium bearing layers is detected in upper ground layers. (author) [French] La prospection est basee sur l'etude de la concentration en radon dans l'air du sol. Dans les terrains superficiels, on decele le radon qui diffuse a partir des couches profondes uraniferes. (auteur)

  10. Certain problems about radon. Pt.1

    International Nuclear Information System (INIS)

    Wu Huishan

    2005-01-01

    Discussion has been made on certain pointed out problems which presently influence the work and development of radon survey, and certain specific problems have been put forward which should be paid much attention and taken measures. Among the problems, some come from cognition, i.e. two kinds of balance and examination about radon, chief culprit of radon's daughter, multiply control and migration, the significance of radon in the water and soil, important standards for designing and evaluating the sites of construction projects, thoughts on the mechanism of the harm of radon and its daughters, diseases causing of both high and low radon, difficulty of emanation of indoor radon, normal low radon from natural marble; and others must be resolved specifically, i.e. establishment of national radon standards as quickly as possible, improvement of on-the-spot examination technique, national-wide radon survey with multiple disciplines and technology, the research on the mechanism of radon's harm and the establishment national radon study center. (authors)

  11. Radon and its daughters in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Rundo, J

    1984-05-01

    Prolonged exposure to radon should build up a reservoir of radon in body fat and fluids. If the subject moved to an environment with a lower radon concentration from an environment with a higher level of radon, the result would be an exhalation of radon, and the initial exhalation rate of radon should depend of the radon concentration inhaled. This paper describes the behavior of radon and its daughters in vivo and a relationship between the radon exhalation rate and the time after a meal. A major but short-lived postprandial increase in the exhalation rate of radon was observed. The author reports a similar effect in the exhalation rate of radon by persons containing no radium. It should be noted that the possibility exists that a large amount of radon daughters in the chest may interfere in the investigation of possible internal contamination with plutonium or other actinides by external counting. 8 figures.

  12. Measurement of exhalation rate of radon and radon concentration in air using open vial method

    International Nuclear Information System (INIS)

    Horiuchi, Kimiko; Ishii, Tadashi.

    1991-01-01

    It was recognized that more than half of total exposure dose on human subject is caused by radon and its decay products which originate from naturally occurring radioactive substances (1988 UNSCEAR). Since then the exhalation of radon from the ground surface has received increasing attention. The authors have developed a new method for the determination of radon in natural water using toluene extraction of radon and applying a liquid scintillation counter of an integral counting technique which is able to get the absolute counting of radon. During these studies, the authors found out that when a counting vial containing of Liquid scintillator (LS)-toluene solution, without a lid, is exposed to the atmosphere for a while, dissolution of radon clearly occurs due to high solubility of radon into toluene layer. To extend this finding for the determination of radon in the atmosphere, the authors devised a new method to actively collect the atmosphere containing radon in a glass bottle by discharging a definite amount of water in it, which is named as open-vial dynamic method. The radon concentration can be easily calculated after the necessary corrections such as the partition coefficient and others. Applying proposed method to measure the radon exhalation rate from the ground surface and radon concentration in air of the dwelling environment, radioactive mineral spring zone and various geological formation such as granitic or sedimentary rocks. (author)

  13. Risks from radon

    International Nuclear Information System (INIS)

    Doll, Richard

    1992-01-01

    The best estimate of risk to which everyone is exposed from natural radon in buildings is now obtained by extrapolation from observations on men exposed to radon in mines. The relationship between dose and effect derived by the US National Research Council implies that about 6% of the current life-time risk of developing the disease in the UK is attributable to radon, but for residents of some houses it will be much greater. This estimate is dependent on many assumptions, some of which are certainly wrong, and reliable estimates can be obtained only by direct observations on people living in different houses. It is possible that radon may also cause some risk of other cancers, notably leukaemia, but such risks, if real, are certainly small. Studies in progress should provide reliable estimates of all radon induced risks within a few years. (author)

  14. Simulation Analysis of Transmission-Line Impedance Transformers for Petawatt-Class Pulsed Power Accelerators

    International Nuclear Information System (INIS)

    Hu Yixiang; Qiu Aici; Sun Fengju; Huang Tao; Cong Peitian; Wang Liangping; Zeng Jiangtao; Li Yan; Zhang Xinjun; Lei Tianshi

    2011-01-01

    Based on the transmission line code TLCODE, a 1D circuit model for a transmission-line impedance transformer was developed and the simulation results were compared with those in the literature. The model was used to quantify the efficiencies of voltage-transport, energy-transport and power-transport for a transmission-line impedance transformer as functions of ψ (the ratio of the output impedance to the input impedance of the transformer) and Γ (the ratio of the pulse width to the one-way transit time of the transformer) under a large scale of m (the coefficient of the generalized exponential impedance profile). Simulation results suggest that with the increase in Γ, from 0 to ∞, the power transport efficiency first increases and then decreases. The maximum power transport efficiency can reach 90% or even higher for an exponential impedance profile (m = 1). With a consideration of dissipative loss in the dielectric and electrodes of the transformer, two representative designs of the water-insulated transformer are investigated for the next generation of petawatt-class z-pinch drivers. It is found that the dissipative losses in the electrodes are negligibly small, below 0.1%, but the dissipative loss in the water dielectric is about 1% to 4%. (fusion engineering)

  15. Investigations on indoor radon in Austria, Part 1: Seasonality of indoor radon concentration

    International Nuclear Information System (INIS)

    Bossew, Peter; Lettner, Herbert

    2007-01-01

    In general, indoor radon concentration is subject to seasonal variability. The reasons are to be found (1) in meteorological influence on the transport properties of soil, e.g. through temperature, frozen soil layers and soil water saturation; and (2) in living habits, e.g. the tendency to open windows in summer and keep them closed in winter, which in general leads to higher accumulation of geogenic Rn in closed rooms in winter. If one wants to standardize indoor Rn measurements originally performed at different times of the year, e.g. in order to make them comparable, some correction transform as a function of measurement time which accounts for these effects must be estimated. In this paper, the seasonality of indoor Rn concentration measured in Austria is investigated as a function of other factors that influence indoor Rn. Indoor radon concentration is clearly shown to have seasonal variability, with higher Rn levels in winter. However, it is complicated to quantify the effect because, as a consequence of the history of an Rn survey, the measurement season maybe correlated to geological regions, which may introduce a bias in the estimate of the seasonality amplitude

  16. Radon: Detection and treatment

    International Nuclear Information System (INIS)

    Loken, S.; Loken, T.

    1989-01-01

    Within the last few years, natural radon exposure in non-industrial settings, primarily homes, has become a health concern. Research has demonstrated that many homes throughout the United States have radon concentrations much higher than the legal federal limits set for miners. Thousands of unsuspecting people are being exposed to high levels of radiation. It is estimated that up to 15 percent of lung cancers are caused from radon. This is a significant health risk. With basic knowledge of the current information on radon, a primary health care provider can address patients' radon concerns and make appropriate referrals

  17. 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.

  18. 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)

  19. Earthquake precursory studies in Kangra valley of North West Himalayas, India, with special emphasis on radon emission

    International Nuclear Information System (INIS)

    Kumar, Arvind; Singh, Surinder; Mahajan, Sandeep; Bajwa, Bikramjit Singh; Kalia, Rajeev; Dhar, Sunil

    2009-01-01

    The continuous soil gas radon monitoring is carried out at Palampur and the daily monitoring of radon concentration in water is carried out at Dharamshala region of Kangra valley of North West Himalayas, India, a seismic zone V, to study the correlation of radon anomalies in relation to seismic activities. In this study, radon monitoring in soil was carried out by using barasol probe manufactured by Algade France, whereas the radon content in water was recorded using RAD 7 radon monitoring system of Durridge Company USA. The effect of meteorological parameters viz. temperature, pressure, wind velocity, rainfall, and humidity on radon emission has been studied. The seasonal average value and standard deviation of radon in soil and water is calculated to find the radon anomaly to minimize the effect of meteorological parameters on radon emission. The radon anomalies observed in the region have been correlated with the seismic events of M≥2 reported by Wadia Institute of Himalayas Geology Dehradoon and Indian Meteorological Department, New Delhi in NW Himalayas within 250 km distance from the monitoring stations.

  20. Spectral-ratio radon background correction method in airborne γ-ray spectrometry based on compton scattering deduction

    International Nuclear Information System (INIS)

    Gu Yi; Xiong Shengqing; Zhou Jianxin; Fan Zhengguo; Ge Liangquan

    2014-01-01

    γ-ray released by the radon daughter has severe impact on airborne γ-ray spectrometry. The spectral-ratio method is one of the best mathematical methods for radon background deduction in airborne γ-ray spectrometry. In this paper, an advanced spectral-ratio method was proposed which deducts Compton scattering ray by the fast Fourier transform rather than tripping ratios, the relationship between survey height and correction coefficient of the advanced spectral-ratio radon background correction method was studied, the advanced spectral-ratio radon background correction mathematic model was established, and the ground saturation model calibrating technology for correction coefficient was proposed. As for the advanced spectral-ratio radon background correction method, its applicability and correction efficiency are improved, and the application cost is saved. Furthermore, it can prevent the physical meaning lost and avoid the possible errors caused by matrix computation and mathematical fitting based on spectrum shape which is applied in traditional correction coefficient. (authors)

  1. Radon and radon daughter measurements at and near the former Middlesex Sampling Plant, Middlesex, New Jersey

    International Nuclear Information System (INIS)

    Haywood, F.F.; Perdue, P.T.; Christian, D.J.; Leggett, R.W.; Dickson, H.W.; Myrick, T.E.

    1980-03-01

    The results of the radon and radon daughter measurements made to date (1978) at the Middlesex Sampling Plant in Middlesex, New Jersey, are presented in this report. These measurements were one portion of a more comprehensive radiological survey conducted at this site and the surrounding area from 1976 to 1978. The surveyed property served as a uranium ore sampling plant during the 1940's and early 1950's and as a result contains elevated levels of surface an subsurface contamination. On-site indoor radon daughter and radon concentrations exceeded both the US Surgeon General Guidelines and the Nuclear Regulatory Commission's maximum permissible concentration limits for radon (10 CFR Part 20) in all structures surveyed. Off-site structures showed concentrations of radon and radon daughters at or only slightly above background levels, except for one site where the radon levels were found to be above the 10 CFR Part 20 guidelines. Outdoor radon ad radon daughter concentrations, measured both on and off the site, were well below the guidelines, and the data give no indication of significant radon transport from the site

  2. Geographical associations between radon and cancer: is domestic radon level a marker of socioeconomic status?

    International Nuclear Information System (INIS)

    Wolff, S.P.; Stern, G.

    1991-01-01

    Previous studies showing a geographical association between radon and various cancers, particularly the leukaemias and lymphomas, appear to be confounded by the role of radon levels as a surrogate for socioeconomic status. Higher socioeconomic status (at least at the UK county level) is correlated with higher levels of domestic radon. Controlling for the relationship between socioeconomic status and radon removes the correlation between radon exposure and lymphoproliferative disease. Reported associations between radon and lymphoproliferative disease (and possibly other cancers) may be secondary to socioeconomic variables. (author)

  3. Inverse method for determining radon diffusion coefficient and free radon production rate of fragmented uranium ore

    International Nuclear Information System (INIS)

    Ye, Yong-jun; Wang, Li-heng; Ding, De-xin; Zhao, Ya-li; Fan, Nan-bin

    2014-01-01

    The radon diffusion coefficient and the free radon production rate are important parameters for describing radon migration in the fragmented uranium ore. In order to determine the two parameters, the pure diffusion migration equation for radon was firstly established and its analytic solution with the two parameters to be determined was derived. Then, a self manufactured experimental column was used to simulate the pure diffusion of the radon, the improved scintillation cell method was used to measure the pore radon concentrations at different depths of the column loaded with the fragmented uranium ore, and the nonlinear least square algorithm was used to inversely determine the radon diffusion coefficient and the free radon production rate. Finally, the solution with the two inversely determined parameters was used to predict the pore radon concentrations at some depths of the column, and the predicted results were compared with the measured results. The results show that the predicted results are in good agreement with the measured results and the numerical inverse method is applicable to the determination of the radon diffusion coefficient and the free radon production rate for the fragmented uranium ore. - Highlights: • Inverse method for determining two transport parameters of radon is proposed. • A self-made experimental apparatus is used to simulate radon diffusion process. • Sampling volume and position for measuring radon concentration are optimized. • The inverse results of an experimental sample are verified

  4. Detecting mammographically occult cancer in women with dense breasts using Radon Cumulative Distribution Transform: a preliminary analysis

    Science.gov (United States)

    Lee, Juhun; Nishikawa, Robert M.; Rohde, Gustavo K.

    2018-02-01

    We propose using novel imaging biomarkers for detecting mammographically-occult (MO) cancer in women with dense breast tissue. MO cancer indicates visually occluded, or very subtle, cancer that radiologists fail to recognize as a sign of cancer. We used the Radon Cumulative Distribution Transform (RCDT) as a novel image transformation to project the difference between left and right mammograms into a space, increasing the detectability of occult cancer. We used a dataset of 617 screening full-field digital mammograms (FFDMs) of 238 women with dense breast tissue. Among 238 women, 173 were normal with 2 - 4 consecutive screening mammograms, 552 normal mammograms in total, and the remaining 65 women had an MO cancer with a negative screening mammogram. We used Principal Component Analysis (PCA) to find representative patterns in normal mammograms in the RCDT space. We projected all mammograms to the space constructed by the first 30 eigenvectors of the RCDT of normal cases. Under 10-fold crossvalidation, we conducted quantitative feature analysis to classify normal mammograms and mammograms with MO cancer. We used receiver operating characteristic (ROC) analysis to evaluate the classifier's output using the area under the ROC curve (AUC) as the figure of merit. Four eigenvectors were selected via a feature selection method. The mean and standard deviation of the AUC of the trained classifier on the test set were 0.74 and 0.08, respectively. In conclusion, we utilized imaging biomarkers to highlight differences between left and right mammograms to detect MO cancer using novel imaging transformation.

  5. Elastic neutron diffraction study of transforming and non-transforming single crystal ZrV2

    International Nuclear Information System (INIS)

    Bostock, J.; Wong, M.; MacVicar, M.L.A.; Levinson, M.

    1980-01-01

    The mosaic spread of single crystal ZrV 2 is unusually narrow, approx. 1' from room temperature to 130K. For non-transforming perfect single crystal the mosaic gradually increases to approx. 1.86' at 4.2K; for transforming, twinned single crystal the room temperature mosaic is maintained to 110K, then increases to 2.76' at 94K when the crystal transforms to a mixed cubic (30%) and rhombohedral state (70%). The onset of the electronic instability (approx. 100K) is accompanied by an increase in diffuse scattering background which, for the twinned crystal, peaks at the structural transformation. The electronic instability coupled to the localized lattice stress appears to be the driving mechanism for the transformation

  6. Studies of Radon and Radon Progeny in Air Conditioned Rooms in Hospitals

    International Nuclear Information System (INIS)

    Marley, F.; Denman, A.R.; Phillips, P.S.

    1998-01-01

    A series of continuous real-time radon and radon progeny measurements together with passive etched track detector measurements were performed in hospital premises during 1996. In one small room, detailed measurements over several weeks showed that both the radon concentration and the Equilibrium Factor depended on the intermittent operation of a filtered positive pressure displacement air-conditioning system, which was designed to conform to operating theatre standards. The average radon level measured while the air-conditioning was off was almost four times higher than that recorded whilst it was on. The progeny level was over five times higher than that whilst it was on. Thus, the Equilibrium Factor (F), was significantly lower when the air-conditioning was on. Measurements in similar rooms in two hospitals, confirmed that the reduction in radon level was a general finding. Thus staff working in such environments receive significantly lower radiation dose from radon than staff working in nearby normally ventilated rooms. (author)

  7. 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.)

  8. Radon in workplaces

    International Nuclear Information System (INIS)

    Markkanen, M.; Annanmaeki, M.; Oksanen, E.

    2000-01-01

    The EU Member States have to implement the new Basic Safety Standards Directive (BSS) by May 2000. The Title VII of the Directive applies in particular to radon in workplaces. The Member States are required to identify workplaces which may be of concern, to set up appropriate means for monitoring radon exposures in the identified workplaces and, as necessary, to apply all or part of the system of radiological protection for practices or interventions. The BSS provisions on natural radiation are based on the ICRP 1990 recommendations. These recommendations were considered in the Finnish radiation legislation already in 1992, which resulted in establishing controls on radon in all types of workplaces. In this paper issues are discussed on the practical implementation of the BSS concerning occupational exposures to radon basing on the Finnish experiences in monitoring radon in workplaces during the past seven years. (orig.) [de

  9. 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

  10. 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

  11. A 150 kV Isolation Transformer for a Neutron Generator

    International Nuclear Information System (INIS)

    Dechthummarong, C.; Pratumtip, P.; Thongleurm, C.; Vichaimongkol, P.; Charoennugul, R.; Vilaithong, T.

    1998-01-01

    The work aims at the design and construction of a 150 kV isolation transformer for a neutron generator. The transformer windings are designed to use cylindrical layers with circular enamel copper wires. The insulation of the dry type transformer uses the epoxy resin for encapsulated winding. This insulation is non-flammable under temperature 350 degree celsius and the breakdown voltage is 10-18 kV/mm. This insulation is suitable for insulating high voltage. The design of provides the temperature rise of winding not exceeding 65 degree celsius for protection of the cracking of epoxy resin due to the expansion of winding

  12. 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

  13. Radon measurements in underground and ground constructions in Tashkent city

    International Nuclear Information System (INIS)

    Akimov, V.A.; Yafasov, A.Y.; Vasidov, A.; En, Z.; Tillaev, T.; Tsipin, V.Z.

    2002-01-01

    More than half of the dose of the natural radioactivity received by population is related to radon and its progeny. Investigations of scientists all over the world have shown that excessive radon and its progeny exposure dose is associated with a risk of lung cancer. Short-lived radon daughters (Po-218 and Po-214) are considered to be of the most dangers. At a relaxation process resulting from an earthquake, the radon gas can release from the accumulators and get indoors, that enhances greatly the radon level there. According to seismologists data, as a result of the strong Tashkent earthquake in 1966, extensive breaks and faults have been formed along the city and its neighborhoods. The aim of our work was evaluation of radon concentration level and its variation in Tashkent subway stations and related underground offices and also in apartments of multi story buildings and detached houses. The measurements were conducted by two different techniques-with ionization chamber radiometer 'Alpha GUARD' and with solid state nuclear track detectors. The Alpha GUARD radiometer operates either in the mode of passive sampling, or by pumping air through the ionization camera being of 0.6 l in volume. The radiometer is capable of measuring a volumetric activity of radon-222 in air (Bq/m3), and it is equipped with the devices that measure some environmental parameters such as temperature, relative humidity and air pressure. The range of V A of 222 Rn in air the device is able to measure is 10 to 2x10 6 Bq/m 3 , sensitivity is 1 pulse/min for 20 Bq/m 3 , and its self-background is less than 1 Bq/m 3 . The radon measurements in Tashkent subway stations and underground offices have shown that daily mean radon values were in the range of 14-65 Bq/m 3 , except for the Pushkin Station, where the daily mean V A was 137 Bq/m3. Such a high radon level is connected with availability near the station of one of the numerous faults and fractures of the terrestrial crust responsible for the

  14. Submicrosecond linear pulse transformer for 800 kV voltage with modular low-inductance primary power supply

    Energy Technology Data Exchange (ETDEWEB)

    Bykov, Yu. A.; Krastelev, E. G., E-mail: ekrastelev@yandex.ru; Popov, G. V.; Sedin, A. A.; Feduschak, V. F. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2016-12-15

    A pulsed power source with voltage amplitude up to 800 kV for fast charging (350–400 ns) of the forming line of a high-current nanosecond accelerator is developed. The source includes capacitive energy storage and a linear pulse transformer. The linear transformer consists of a set of 20 inductors with circular ferromagnetic cores surrounded by primary windings inside of which a common stock adder of voltage with film-glycerol insulation is placed. The primary energy storage consists of ten modules, each of which is a low-inductance assembly of two capacitors with a capacitance of 0.35 μF and one gas switch mounted in the same frame. The total energy stored in capacitors is 5.5 kJ at the operating voltage of 40 kV. According to test results, the parameters of the equivalent circuit of the source are the following: shock capacitance = 17.5 nF, inductance = 2 μH, resistance = 3.2 Ω.

  15. Radon in dwellings

    International Nuclear Information System (INIS)

    Erikson, B.E.; Boman, C.A.; Nyblom, L.; Swedjemark, G.A.

    1980-06-01

    The report presents the function of the ventilation by natural draught in three-storey houses. In some cases also the measurement of gamma radiation, radon and radon daughters was made. The investigation took place in Uppsala. The houses were built of light weight concrete made of alum-shale. The measurements showed that the contents of radon daughters were far below the provisional limits. (G.B.)

  16. 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...

  17. 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.

  18. Comparing summer and winter indoor radon and radon daughters activity in Campinas, Brazil

    International Nuclear Information System (INIS)

    Guedes, O.S.; Hadler, N.J.C.; Iunes, P.J.; Neman, R.S.; Souza, W.F.; Tello, S.C.A.; Paulo, S.R.

    2002-01-01

    We developed a technique - based on alpha particle track detection using CR-39 - where the activity originated from indoor radon can be potentially separated into three fraction: (i) radon in the air, (ii) radon daughters (RD), 218 Po and 214 Po, in the air and (iii) RD plated-out on the detector surface during exposure. In this work only a partial separation was carried out, then our results are limited to radon plus RD in the air and RD attached to detector surface. These activities can be separated if size and gray level of the round tracks are measured using an automatic optical microscopy system.Our group carried out an indoor radon and radon daughters (RD) survey in Campinas made up by a summer (November, 96 to May, 97) and a winter (May, 97 to November, 97) exposure, where the detectors were placed in the same rooms of the same dwellings (approximately 100) in both cases. Comparing winter and summer alpha activity for the detectors analyzed up to now, approximately 45 dwellings, we observed that: i) it seems that the source of radon is the material (brick and concrete mainly) making up walls, floor and ceiling of the dwellings, ii) there is no clear relationship between intensity of aeration and the activities measured in this work, and iii) the average ratio between winter and summer activity in the air (radon plus RD) is approximately equal to similar ratios observed in other countries, but for radon only. (author)

  19. 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.

  20. Indoor radon and radon daughters survey at Campinas-Brazil using CR-39: First results

    International Nuclear Information System (INIS)

    Guedes, S.; Hadler, J.C.N.; Iunes, P.J.; Navia, L.M.S.; Neman, R.S.; Paulo, S.R.; Rodrigues, V.C.; Souza, W.F.; Tello, C.A.S.; Zuniga, A.

    1999-01-01

    The first results of a radon and radon daughters (RD) survey performed at Campinas-SP, Brazil, are presented. We employed a technique that, potentially, makes possible to measure the radon and RD activity in the air and to separate from this result the activity of radon, alone. In this preliminary paper only the former activity is studied

  1. Indoor radon and radon daughters survey at Campinas-Brazil using CR-39: First results

    CERN Document Server

    Guedes, S; Iunes, P J; Navia, L M S; Neman, R S; Paulo, S R; Rodrigues, V C; Souza, W F; Tello, C A S; Zúñiga, A G

    1999-01-01

    The first results of a radon and radon daughters (RD) survey performed at Campinas-SP, Brazil, are presented. We employed a technique that, potentially, makes possible to measure the radon and RD activity in the air and to separate from this result the activity of radon, alone. In this preliminary paper only the former activity is studied.

  2. Off-resonance transformer charging for 250-kV water Blumlein

    International Nuclear Information System (INIS)

    Cook, E.; Reginato, L.

    1978-01-01

    An off-resonance transformer for charging a 250-kV Blumlein system provides a viable alternative to other charging schemes by permitting the use of conventional thyratrons. Such a transformer must have reliability, a reasonable voltage step-up, and a non-reversing primary current. The analysis, design, and performance data for such a transformer are presented. The strong interrelationship between transformer design and Blumlein requirements necessitates that Blumlein description and design criterion be briefly presented prior to transformer design such that transformer load requirements be defined

  3. Radon as a hydrological indicator

    Energy Technology Data Exchange (ETDEWEB)

    Komae, Takami [National Research Inst. of Agricultural Engineering, Tsukuba, Ibaraki (Japan)

    1997-02-01

    The radon concentration in water is measured by a liquid scintillation method. After the radioactive equilibrium between radon and the daughter nuclides was attained, the radon concentration was determined by the liquid scintillation analyzer. {alpha}-ray from radon, then two {beta}- and two {alpha}-ray from the daughter nuclei group were released, so that 500% of the apparent counting efficiency was obtained. The detector limit is about 0.03 Bq/l, the low value, which corresponds to about 5.4x10{sup -15} ppm. By determining the radon concentration in groundwater, behavior of radon in hydrological process, the groundwater exchange caused by pumping and exchange between river water and groundwater were investigated. The water circulation analysis by means of radon indicator in the environment was shown. By using the large difference of radon concentration between in river water and in groundwater, arrival of injected water to the sampling point of groundwater was detected. (S.Y.)

  4. Changing from booster transformer system to auto transformer system in the Kiruna-Raatsi-Svappavaara line in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Buelund, A.; Hellstroem, U. [Banverket, Swedisch National Rail Administration Engineering Dept., Borlaenge (Sweden); Varju, G. [Technical Univ. Budapest (Hungary). Dept. of Electrical Power System

    1999-07-01

    A study of the changeover from a booster transformer (BT) system to an auto transformer (AT) system has been initiated by Banverket to increase the transport capability (weight and speed) of a heavily loaded freight train lines of about 40 km situated between Raatsi and Svappavaara and fed from the Kiruna converter station. In this paper, firstly, a survey of comparison is given on the bases of sophisticated three-conductor line simulations for the two supply schemes in the point of view of equivalent impedance, losses, power rating for actual traffic conditions, longitudinal induction to line-side telecommunication cable, rail-to-earth and rail-to-rail potential. The results of simulation calculations have provided the necessary information on the rating of the AT scheme including the required number and locations of the auto transformers. At AT system has been installed in addition to the already existing BT without the removal of the BT system. This installation has allowed to change from one system to the other in one day period of time and thus giving the possibility of performing real scale comparison tests between the two schemes. The paper presents a survey of the results of two week time site measurements. (orig.)

  5. Control of radon in Finnish workplaces

    International Nuclear Information System (INIS)

    Markkanen, M.

    2002-01-01

    Natural radiation in Finland is regulated in the Finnish Radiation Act from 1992. Occupational exposure to natural radiation is regulated by an amendment of the Radiation Decree in 1998. The most important issues in Finland are radon in workplaces, radioactivity in drinking water and in building materials, and mining and industrial processes. Radon levels in mines have been measured regularly since 1972. Finland has an action level for radon in workplaces of 400 Bq/m 3 . Radon prone areas have been identified primarily from measurements of radon in dwellings. Radon measurements are compulsory in workplaces in radon prone areas unless it can be shown by other means that radon levels are low. A programme focusing on radon in workplaces was initiated in 1992. To date, radon measurements have been carried out in 10,000 workplaces and remedial actions have been taken in 200 of these. The average reduction in radon concentration in remediated buildings is about 1,500 Bq/m 3 . Identification of NORM industries is based on the radionuclide content of the materials used (>1.4 Bq/g U and >0.4 Bq/g Th). The occupational exposure should not exceed 1 mSv/y (excluding radon)

  6. Research on Line Patrol Strategy of 110kV Transmission Line after Lightning Strike

    Directory of Open Access Journals (Sweden)

    Li Mingjun

    2016-01-01

    Full Text Available Lightning faults occupy in the majority of instantaneous fault and reclosing can usually be successful, so power supply can be restored without immediate patrol in many cases. Firstly, this paper introduces the lightning fault positioning and identifying method. Then test electrical performance of insulators after lightning strike from 110kV lines. Data shows that lightning strike has little effect on the electric performance of insulator. Finally, illustrating disposal process of the 110 kV transmission line after lightning fault, certifying that the power supply reliability be ensured without line patrol.

  7. Lessons from radon

    International Nuclear Information System (INIS)

    Nichols, M.

    1993-01-01

    At EPA there is a public outreach program that the Office of Air and Radiation (OAR) has developed for radon. To meet the difficult challenge radon presented, OAR's Radon Division developed working relationships with national nonprofit groups who share a mission. These groups have well-established communication networks with their memberships for advancing their goals. Such diverse groups as the American Lung Association, the Advertising Council, the National Association of Counties (NACo), the Consumer Federation of America, the National Association of Homebuilders, and the National Safety Council have joined with EPA to reduce radon health risks. Through this alliance, EPA has been able to take advantage of communication channels that it could never replicate on tis own. Every group working with EPA disseminates the radon message through its own established channels to reach its constituency. These partners wield authority in their fields and are ideal for addressing the concerns of their audiences

  8. Radon mitigation in schools

    International Nuclear Information System (INIS)

    Leovic, K.W.; Craig, A.B.; Saum, D.W.

    1990-01-01

    This article reports on radon mitigation in school buildings. Subslab depressurization (SSD) has been the most successful and widely used radon reduction method in houses. Thus far, it has also substantially reduced radon levels in a number of schools. Schools often have interior footings or thickened slabs that may create barriers for subslab air flow if a SSD system is the mitigation option. Review of foundation plans and subslab air flow testing will help to determine the presence and effect of such barriers. HVAC systems in schools vary considerable and tend to have a greater influence on pressure differentials (and consequently radon levels) than do heating and air-conditioning systems encountered in the radon mitigation of houses. As part of any radon mitigation method, ASHRAE Standard 62-1989 should be consulted to determine if the installed HVAC system is designed and operated to achieve minimum ventilation standards for indoor air quality

  9. 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

  10. 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.

  11. Radon in Syrian houses

    International Nuclear Information System (INIS)

    Othman, I.; Hushari, M.; Raja, G.; Alsawaf, A.

    1996-01-01

    A nationwide investigation of radon levels in Syrian houses was carried out during the period 1991-1993. Passive radon diffusion dosemeters using polycarbonate detectors were distributed in houses all over Syria. Detectors were subjected to electrochemical etching to reveal latent tracks of alpha particles. The mean radon concentration in Syrian houses was found to be 45 Bq m -3 with some values several times higher. This investigation indicated that there were a few houses in Syria that require remedial action. Most houses that have high levels of radon were found in the southern area, especially in the Damascus governorate. The study also indicated that radon concentrations were higher in old houses built from mud with no tiling. (author)

  12. The therapeutic use of radon; Radon als Heilmittel

    Energy Technology Data Exchange (ETDEWEB)

    Deetjen, P [Innsbruck Univ. (Austria). Inst. fuer Physiologie und Balneologie

    1995-09-01

    Spas with a somewhat elevated concentration of Radon{sup 222} (between 300 and 3000 Bq/l) are described to achieve good clinical results in the treatment of chronic rheumatic diseases. Recently a prospective randomized doubel-blind-study proved the pain reducing efficacy of Radon therapy in patients with cervical pain. Studies in experimental animal models have accumulated remarkable data in tissues and organs that provide a rationale to explain the observed effects of Radon therapy in patients. (orig.) [Deutsch] In verschiedenen europaeischen und asiatischen Laendern werden oft schon seit vielen Jahrhunderten Quellen als besonders heilkraeftig beschrieben, die eine etwas erhoehte Aktivitaet an Radon{sup 222} aufweisen (etwas zwischen 300 und 3000 Bq/l). Neuerdings liegt auch eine prospektive randomisierte Doppelblind-Studie vor, die den klinischen Nachweis der Schmerzlinderung durch eine Radonkur erbringt. In tierexperimentellen Untersuchungen wurden unter Radonexposition zahlreiche stimulierende Effekte auf Zellstoffwechsel, Immunabwehr, Abbau toxischer Radikale, DNA-Reparatur-Systeme oder Synthese von Mediatorsubstanzen gemessen, die rationale Ansaetze fuer das Verstaendnis der Wirkung einer Radonexposition im niedrigen Dosisbereich ergeben. (orig.)

  13. Radon and its measurement

    International Nuclear Information System (INIS)

    Penzo, Silvia

    2006-03-01

    The work reviews the topics concerning the problem of the indoor radon and its measurement. The initial stage deals with the general features of radon, from the historical remarks about its discovery to the formation mechanisms in the soil, then passing to describe the transport processes that lead the radon to enter into the buildings. The mean radon concentration distribution among the Italian regions is reported and compared with the situation in the other countries of the world. A particular importance is given to present the national law concerning the radioprotection from the natural sources of ionizing radiations; a paragraph is completely devoted to this argument and to discuss the differences between the Italian approach and the regulations applied in the Test of Europe for both workplaces and dwellings. Chapter 3 describes the different detectors and methods to measure the radon and its short mean live decay products concentrations, together with the operative procedures and guides provided by the Italian law and by the international bodies. As an example of typical radon passive measurement device. the new ENEA detector developed at the Institute of Radioprotection is presented and discussed. Appendix 1 is entirely devoted to discuss the main remedial actions for decreasing the radon indoor concentration both for old and new buildings; appendix 2 reports the main quantities related to radon and radioprotection [it

  14. Evaluation of the performance characteristics of radon and radon-daughter concentration measurement devices under controlled environmental conditions

    International Nuclear Information System (INIS)

    Pearson, M.D.

    1989-04-01

    The Technical Measurements Center (TMC) conducted a study to expose 10 radon and 7 radon-daughter concentration measurement devices in the DOE/GJPO Radon/Radon-Daughter Environmental Chamber for a series of 24 controlled-environment tests. The tests evaluated the devices' response to temperature, relative humidity, dew point, condensation-nuclei concentration, radon-daughter/radon equilibrium ratio, and non-uniform radon and radon-daughter concentration. Devices were evaluated for linear response as a function of concentration. In addition to response to environmental parameters, the evaluation included determining the utility of the devices in providing reasonable assurance of compliance with the radon and radon-daughter concentration standards for DOE remedial action programs. This reasonable assurance criterion is based on a coefficient of variation of 25 percent for devices deployed for year-long measurements and a coefficient of variation of 18 percent for devices deployed for intermittent sampling. 39 refs., 65 figs., 33 tabs

  15. Radon in public buildings

    International Nuclear Information System (INIS)

    Schulz, H.; Flesch, K.; Hermann, E.; Loebner, W.; Leissring, B.

    2009-01-01

    From the Free State of Saxony, a study was commissioned to survey how reliable measurements to characterize the radon situation in public buildings at a reasonable financial and human effort can be carried out to reduce radiation exposure in public buildings. The study approach was for 6 objects. To characterize the radon situation the time evolution measurement of radon concentrations of more than 1 to 2 weeks turned out to be sufficient. A novel data analysis enables the identification of a ''typical daily alteration of the radon concentration'' depending on the ventilation conditions and the daily use of the offices or class rooms. The identification of typical diurnal radon variations for the working time and weekends or holidays is of fundamental importance for assessing the exposure situation in public buildings. It was shown that the radon concentration during working time are in general much lower than in the times when the buildings (offices) are unused. It turned out that the long-term radon measurements with nuclear track detectors within distinct time regimes (day / night, working hours / leisure time) by utilizing switch modules are very efficient to estimate the actual exposure. (orig.)

  16. 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

  17. Technique and equipment for measuring volume activity of radon in the air of radon laboratories and clinics

    International Nuclear Information System (INIS)

    Vorob'ev, I.B.; Krivokhatskij, A.S.; Nekrasov, E.V.; Nikolaev, V.A.; Potapov, V.G.; Terent'ev, M.V.

    1990-01-01

    Usability of a new equipment-technique combination for measuring radon activity in the air of radon laboratories and balneological clinics is studied. The complex includes nitrate-cellulose detector, radon chamber, Aist, Istra type spark counters and technique of spark counting. The method sensitivity is 50 Bqxm 3 , the error is 30%. Usability and advisability of track method in radon laboratories and balneological clinics for simultaneous measurement in several points of integral volumetric radon activities are confirmred. The method permits to carry out rapid and accurate bulk investigations. The results of determining mean volumetric radon activity in the air in different points of radon laboratory and radon clinics are presented

  18. Radon in dwellings the national radon survey Cork and Kerry

    International Nuclear Information System (INIS)

    McGarry, A.T.; Fennell, S.G.; Mackin, G.M.; Madden, J.S.

    1998-07-01

    This report presents the results of the third phase of the National Radon Survey carried out by the Radiological Protection Institute of Ireland. The counties included in this phase are Cork and Kerry. The average radon concentrations for the houses measured in these counties were 76 Bq/m 3 and 70 Bq/m 3 . The measurement data were grouped on the basis of the 10 km grid squares of the Irish National Grid System and used to predict the percentage of dwellings in each grid square which exceeds the Reference Level of 200 Bq/m 3 . Grid squares where this percentage is predicted to be 10% or higher are designated High Radon Areas. The health effects of exposure to high radon levels are discussed and recommendations are made regarding both new and existing dwellings. (author)

  19. Experimental characterization of the flux-line lattice in superconducting V3Si

    International Nuclear Information System (INIS)

    Christen, D.; Chang, Y.; Kerchner, H.; Larson, B.; Narayan, J.; SeKula, S.

    1983-01-01

    Several microscopic properties of the flux-line lattice (FLL) in three separate single crystals of V 3 Si have been investigated by means of small-angle neutron diffraction. These low-field FLL characterizations have been correlated with the following material and superconducting properties: the real crystal symmetry parallel to the applied magnetic field; the micro-structure as determined by TEM; magnetic irreversibilities in the mixed state; reversible flux-line motion in ac response; martensitic structural transformation observed by X-ray diffraction. The three samples, V 3 Si-MP3, -MP4, and -MP5 possessed different defect structures, and this was manifested foremost in the FLL perfection. At low field (B 0-.5 T, but a highly mosaic, nearly polycrystalline FLL at lower fields. Sample MP4 contained large (500-1000 A) incoherent precipitates, and showed only a polycrystalline FLL at low field. In both MP3 and MP5, distinct anisotropic correlations were observed between the FLL morphology and the real-crystal direction along the applied field. The FLL perfection was strongly dependent on the growth history. The peak width history dependence for two different scattering geometries can be qualitatively modeled by proposed flux-pinning mechanisms. Quantitative comparisons with critical current measurements, however, are not totally reconcilable

  20. Self-organised critical features in soil radon and MHz electromagnetic disturbances: Results from environmental monitoring in Greece

    International Nuclear Information System (INIS)

    Petraki, Ermioni; Nikolopoulos, Dimitrios; Fotopoulos, Anaxagoras; Panagiotaras, Dionisios; Koulouras, Grigorios; Zisos, Athanasios; Nomicos, Constantinos; Louizi, Anna; Stonham, John

    2013-01-01

    This paper addresses the issues of self-organised critical behaviour of soil-radon and MHz-electromagnetic disorders during intense seismic activity in SW Greece. A significant radon signal is re-analysed for environmental influences with Fast Fourier Transform and multivariate statistics. Self-organisation of signals is investigated via fractal evolving techniques and detrended fluctuation analysis. New lengthy radon data are presented and analysed accordingly. The data did not show self-similarities. Similar analysis applied to new important concurrent MHz-electromagnetic signals revealed analogous behaviour to radon. The signals precursory value is discussed. - Highlights: ► New radon–MHz signals for an area with peculiar radon disorders on 2008. ► Use of spectrograms-multivariate statistics in analysing environmental parameters. ► Spectral fractal techniques and Detrended Fluctuation Analysis in all signals. ► Pre-earthquake signals followed fractional Brownian motion model. ► Hurst analysis showed persistent–antipersistent self-organised critical patterns.

  1. Radon programmes and health marketing.

    Science.gov (United States)

    Fojtikova, Ivana; Rovenska, Katerina

    2011-05-01

    Being aware of negative health effects of radon exposure, many countries aim for the reduction of the radon exposure of their population. The Czech radon programme was commenced >20 y ago. Since then experts have gathered a lot of knowledge, necessary legislation has been enacted, tens of thousands of inhabitants have been offered free measurement and subsidy for the mitigation. Despite the effort, the effectiveness of the radon programme seems to be poor. Newly built houses still exhibit elevated radon concentrations and the number of houses mitigated is very low. Is it possible to enhance the effectivity of radon programme while keeping it on a voluntary basis? One possible way is to employ health marketing that draws together traditional marketing theories and science-based strategies to prevention. The potential of using marketing principles in communication and delivery of radon information will be discussed.

  2. Leukaemia risks and radon

    International Nuclear Information System (INIS)

    Wolff, S.P.

    1991-01-01

    A correlation has been established between domestic radon exposure and mutation in peripheral T lymphocytes. Some caution must be exercised, however, in interpreting this result as evidence that levels of domestically encountered radon are sufficient to cause leukaemogenic chromosomal alterations. Radon may simply be acting as a surrogate for some other mutagenic factor. Correlations with Local Authority statistics collected in the United Kingdom 1981 Census appear to show that lower domestic radon levels reflect relatively greater socioeconomic deprivation whereas higher levels reflect greater prosperity. The relative risk of lymphoproliferative disease correlates with the same factors that determine domestic radon levels at the county level. Putative relationships between domestic radon exposure and cancer thus need to be controlled for socioeconomic status and associated factors, at least at the county level. (The correlations may not apply to smaller areas.) Similarly, the causative factors underlying the relationships between higher regional socioeconomic status and leukaemia require closer examination. (author)

  3. Radon in workplaces: First results of an extensive survey and comparison with radon in homes

    International Nuclear Information System (INIS)

    Bucci, S.; Pratesi, G.; Viti, M. L.; Pantani, M.; Bochicchio, F.; Venoso, G.

    2011-01-01

    Extensive radon surveys have been carried out in many countries only in dwellings, whereas surveys in workplaces are rather sparse and generally restricted to specific workplaces/activities, e.g. schools, spas and caves. Moreover, radon-prone areas are generally defined on the basis of radon surveys in dwellings, while radon regulations use this concept to introduce specific requirements in workplaces in such areas. This approach does not take into account that work activities and workplace characteristics can significantly affect radon concentration. Therefore, an extensive survey on radon in different workplaces have been carried out in a large region of Italy (Tuscany), in order to evaluate radon distribution in workplaces over the whole territory and to identify activities and workplace characteristics affecting radon concentration. The results of this extensive survey are compared with the results of the survey carried out in dwellings in the same period. The workplaces monitored were randomly selected among the main work activities in the region, including both public and industrial buildings. The survey monitored over 3500 rooms in more than 1200 buildings for two consecutive periods of ∼6 months. Radon concentration was measured by means of passive nuclear track detectors. (authors)

  4. The significance of radon in radioactive pollution of environment. Pt. 2. Radon effect on living organism

    International Nuclear Information System (INIS)

    Kossakowski, S.; Dziura, A.; Kossakowski, A.

    1998-01-01

    Authors review the history of radon monitoring. Epidemiological studies of lung cancer and its correlation to radon concentration in mines and buildings are described. The influence of radon on animals living in the buildings built from waste materials is described. Authors review plans concerning creation of radon monitoring system in Poland. The necessity of monitoring influence of radon on animals is described

  5. Monitoring of radon concentration in dwellings

    International Nuclear Information System (INIS)

    Kurosawa, Ryuhei

    1991-01-01

    Radon problems in dwellings have recently received much attention. Radon concentration in dwellings, as well as in the general environment, varies with various factors such as meteorological conditions and soil components. Therefore, a long term monitoring of radon concentration is required to obtain an average concentration. This paper reviews a passive type radon monitor that is handy and allows a long term radon monitoring. It provides the structure and principle of the radon monitor, covering the type, filter function, sensitivity of diffusion collecting type (cup type), electrostatic collecting type, adsorption collecting type, and detector of radon monitor. Actual examples of the radon monitor are also given. Radon daughter nuclides will have become major foci of exposure countermeasures. In the future, the development of a passive type monitor for determining potential alpha energy concentration is required. (N.K.)

  6. Intercomparison of active and passive instruments for radon and radon progeny in North America

    International Nuclear Information System (INIS)

    George, A.C.; Tu, Keng-Wu; Knutson, E.O.

    1995-02-01

    An intercomparison exercise for radon and radon progeny instruments and methods was held at the Environmental Measurements Laboratory (EML) from April 22--May 2, 1994. The exercise was conducted in the new EML radon test and calibration facility in which conditions of exposure are very well controlled. The detection systems of the intercompared instruments consisted of. (1) pulse ionization chambers, (2) electret ionization chambers, (3) scintillation detectors, (4) alpha particle spectrometers with silicon diodes, surface barrier or diffused junction detectors, (5) registration of nuclear tracks in solid-state materials, and (6) activated carbon collectors counted by gamma-ray spectrometry or by alpha- and beta-liquid scintillation counting. 23 private firms, government laboratories and universities participated with a 165 passive integrating devices consisting of: Activated carbon collectors, nuclear alpha track detectors and electret ionization chambers, and 11 active and passive continuous radon monitors. Five portable integrating and continuous instruments were intercompared for radon progeny. Forty grab samples for radon progeny were taken by five groups that participated in person to test and evaluate their primary instruments and methods that measure individual radon progeny and the potential alpha energy concentration (PAEC) in indoor air. Results indicate that more than 80% of the measurements for radon performed with a variety of instruments, are within ±10% of actual value. The majority of the instruments that measure individual radon progeny and the PAEC gave results that are in good agreement with the EML reference value. Radon progeny measurements made with continuous and integrating instruments are satisfactory with room for improvement

  7. Workshop on dosimetry for radon and radon daughters

    International Nuclear Information System (INIS)

    Turner, J.E.; Holoway, C.F.; Loebl, A.S.

    1978-05-01

    Emphasis is placed on the dosimetry for radon and daughters, rather than on monitoring and instrumentation. The objectives of the meeting were to exchange scientific information, to identify problem areas in radon-daughter dosimetry, and to make any observations or recommendations by the participants through issuance of this report. The discussion topics included the history of dosimetry for radon and daughters, human data, aerosols, deposition and movement in the respiratory tract, dose calculations, dose-to-working-level-month (WLM) conversion factors, animal experiments, and the development of regulations and remedial criteria for reducing population exposures to radon daughters. This report contains a summary of Workshop discussions plus individual statements contributed by several of the participants. The outstanding problem areas from the standpoint of dosimetry appear to involve the appropriate lung organ mass to be used (average lung-tissue dose vs. high-level local dose); recognition of the discrete, rather than continuous, structure of the mucus; lack of knowledge about lung clearance; the variability of dose with the degree of disequilibrium and the unattached fraction of radon daughters for a given WLM; and questions about the character of uranium mine atmospheres actually breathed in the older mines from which much of the epidemiological information originates. The development of criteria for taking remedial action to reduce exposures involves additional concerns of basing long-term risk assessment on short-term sampling and applying WLM data for miners to general populations

  8. Development of 600 kV triple resonance pulse transformer.

    Science.gov (United States)

    Li, Mingjia; Zhang, Faqiang; Liang, Chuan; Xu, Zhou

    2015-06-01

    In this paper, a triple-resonance pulse transformer based on an air-core transformer is introduced. The voltage across the high-voltage winding of the air-core transformer is significantly less than the output voltage; instead, the full output voltage appears across the tuning inductor. The maximum ratio of peak load voltage to peak transformer voltage is 2.77 in theory. By analyzing pulse transformer's lossless circuit, the analytical expression for the output voltage and the characteristic equation of the triple-resonance circuit are presented. Design method for the triple-resonance pulse transformer (iterated simulation method) is presented, and a triple-resonance pulse transformer is developed based on the existing air-core transformer. The experimental results indicate that the maximum ratio of peak voltage across the load to peak voltage across the high-voltage winding of the air-core transformer is approximately 2.0 and the peak output voltage of the triple-resonance pulse transformer is approximately 600 kV.

  9. The Pennsylvania radon story

    International Nuclear Information System (INIS)

    Gerusky, T.M.

    1987-01-01

    In December 1984, the Pennsylvania Bureau of Radiation Protection found itself confronted with the discovery of a home in eastern Pennsylvania having the highest level of radon daughters ever reported. The Bureau responded with a massive radon monitoring, educational, and remediation effort. As of November, 1986, over 18,000 homes had been screen for radon daughters, of which approximately 59% were found to have levels in excess of the 0.020 Working Level guideline. Pennsylvania's response to the indoor radon problem is detailed in this article

  10. 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

  11. Unattached radon daughter atoms and radon daughter equilibrium ratios in uranium mines. Final report

    International Nuclear Information System (INIS)

    Holaday, D.A.

    1972-01-01

    Uranium mines in Colorado and New Mexico were surveyed for airborne concentrations of radon (10043922) and radon daughters. A procedure for measuring individual daughters and the fraction of each existing as free atoms was developed and used for field monitoring. Samples were taken in working areas and particle counts were made. The data was analyzed to determine the ratio of radon to radon daughters as well as the ratios among the radon daughters. The author concludes that since the radon to working level ratios have not changed much in 20 years, using the ratio as the basis for estimating relative biological hazard is just as uncertain now as then. The large number of daughters present as free atoms indicate that the lung radiation doses calculated using any of the lung models need reexamination

  12. Interaction of radon Exposure and cigarette smoking on cells

    International Nuclear Information System (INIS)

    Zhu, Maoxiang; Wei, Han; Yang, Zhihua; Pan, Xiujie; Cao, Zhenshan

    2008-01-01

    Full text: Environmental radon and its progenies is important lung carcinogen both in occupational underground miners and in the general population. Exposure to radon often occurs combined with smoking, another most important lung carcinogen. The join biological effects of alpha- particle radiation and cigarette smoke condense (CSC) were investigated here in order to provide experimental base for medical protection from lung cancer inducing by joint exposure of radon and smoking. Immortalized human bronchial epithelial cells (BEP2D) were divided into 5 groups, namely normal control group (NC), alpha particles irradiation group (0.25 Gy,α), CSC administration group (1μg/ml, CSC), CSC administration (1μg/ml) before (CSC + α) and after (α + CSC) alpha particles irradiation (0.25 Gy) group. On the 35 th passage after treated by alpha particles irradiation and CSC singly or jointly, only α + CSC cells showed malignant transformation characteristics, representing anchor growing independently, losing contact inhibition, and cell cycle disordering, whereas, there were no distinct difference between cells of other groups and normal cells. Moreover, comparison to the groups treated alone with alpha particles radiation or CSC administration, in the groups of joint exposure to alpha particles radiation and CSC treatment, cell survival fractions markedly decreased, intracellular ROS levels, frequencies of comet cell generation significantly increase, and could found that cell survival fractions of group CSC administration after α particle radiation was significantly higher than that of group CSC administration before alpha particles irradiation, suggesting that interaction of radon and smoking associated with their exposure sequence. In summary, interaction of radon and smoking was synergistic effect, and which was impacted by the order of exposure. (author)

  13. Radon Research Program, FY-1990

    International Nuclear Information System (INIS)

    1991-03-01

    The Department of Energy (DOE) Office of Health and Environmental Research (OHER) has established a Radon Research Program with the primary objectives of acquiring knowledge necessary to improve estimates of health risks associated with radon exposure and also to improve radon control. Through the Radon Research Program, OHER supports and coordinates the research activities of investigators at facilities all across the nation. From this research, significant advances are being made in our understanding of the health effects of radon. OHER publishes this annual report to provide information to interested researchers and the public about its research activities. This edition of the report summarizes the activities of program researchers during FY90. Chapter 2 of this report describes how risks associated with radon exposure are estimated, what assumptions are made in estimating radon risks for the general public, and how the uncertainties in these assumptions affect the risk estimates. Chapter 3 examines how OHER, through the Radon Research Program, is working to gather information for reducing the uncertainties and improving the risk estimates. Chapter 4 highlights some of the major findings of investigators participating in the Radon Research Program in the past year. And, finally, Chapter 5 discusses the direction in which the program is headed in the future. 20 figs

  14. Radon - The management of the risk related to radon

    International Nuclear Information System (INIS)

    2010-01-01

    This leaflet briefly explains what radon is, where it comes from, and what it becomes. It indicates and briefly comments its concentrations in French departments, describes how radon can affect our health (lung cancer), describes how the risk can be reduced in buildings, and indicates the existing regulatory provisions

  15. Radon programmes and health marketing

    International Nuclear Information System (INIS)

    Fojtikova, I.; Rovenska, K.

    2011-01-01

    Being aware of negative health effects of radon exposure, many countries aim for the reduction of the radon exposure of their population. The Czech radon programme was commenced >20 y ago. Since then experts have gathered a lot of knowledge, necessary legislation has been enacted, tens of thousands of inhabitants have been offered free measurement and subsidy for the mitigation. Despite the effort, the effectiveness of the radon programme seems to be poor. Newly built houses still exhibit elevated radon concentrations and the number of houses mitigated is very low. Is it possible to enhance the effectivity of radon programme while keeping it on a voluntary basis? One possible way is to employ health marketing that draws together traditional marketing theories and science-based strategies to prevention. The potential of using marketing principles in communication and delivery of radon information will be discussed. (authors)

  16. Radon in buildings

    International Nuclear Information System (INIS)

    Ryan, N.M.; Finn, M.

    1995-01-01

    This guide is intended to inform designers, contractors, householders and other building owners about radon in buildings and to provide guidance where it has been decided to take action to reduce radon levels. It gives some pointers to good practice insofar as it relates to non complex buildings of normal design and construction. Reference is made to the usual ways of reducing l;levels of radon and guidance is given on sources of further information. I

  17. Radon in dwellings the national radon survey Galway and Mayo

    International Nuclear Information System (INIS)

    McGarry, A.T.; Fennell, S.G.; Mackin, G.M.; Madden, J.S.; O'Colmain, M.

    1999-07-01

    This report presents the results of the final phase of the National Radon Survey carried out by the Radiological Protection Institute of Ireland. The counties included in this phase are Galway and Mayo. The average radon concentrations for the houses measured in these counties were 112 Bq/m 3 and 100 Bq/m 3 , respectively. The measurement data were grouped on the basis of the 10 km grid squares of the Irish National Grid System and used to predict the percentage of dwellings in each grid square which exceeds the Reference Level of 200 Bq/m 3 . Grid squares where this percentage is predicted to be 10% or higher are designated High Radon Areas. The health effects of exposure to high radon levels are discussed and recommendations are made regarding both new and existing dwellings. (author)

  18. The use of mechanical ventilation with heat recovery for controlling radon and radon-daughter concentrations

    International Nuclear Information System (INIS)

    Nazaroff, W.W.; Boegel, M.L.; Hollowell, C.D.; Roseme, G.D.

    1980-01-01

    An energy research house in Maryland was found to have radon concentrations far in excess of recommended guidelines. A mechanical ventilation system with heat recovery was installed in this house to test its effectiveness as an energy-efficient control technique for indoor radon. Radon concentration was monitored continuously for two weeks under varying ventilation conditions (0.07 to 0.8 air changes per hour (ach)) and radon daughter concentrations were measured by grab-sample techniques about nine times daily during this period. At ventilation rates of 0.6 ach and higher radon and radon daughter levels dropped below guidelines for indoor concentrations. Comparison with other studies indicates that indoor radon buildup may be a problem in a considerable portion of houses characterized by their low infiltration rates. The use of mechanical ventilation systems with air-to-air heat exchangers may offer a practical, cost-effective, and energy-efficient means of alleviating not only the radon problem specifically but also the general deterioration of indoor air quality in houses designed or retrofitted to achieve low infiltration

  19. Measurement of radon concentration in water using the portable radon survey meter.

    Science.gov (United States)

    Yokoyama, S; Mori, N; Shimo, M; Fukushi, M; Ohnuma, S

    2011-07-01

    A measurement method for measuring radon in water using the portable radon survey meter (RnSM) was developed. The container with propeller was used to stir the water samples and release radon from the water into the air in a sample box of the RnSM. In this method, the measurement of error would be water was >20 Bq l(-1).

  20. Comparative study of radon concentration in selected modern and traditional building at Kenyatta University

    International Nuclear Information System (INIS)

    Chege, W.M.; Rathore, I.V.S.; Chhabra, S.C.; Mustapha, A.O.

    2010-01-01

    Radon is leading source of radiation exposure to the public and increases risk of cancer (UNSCEAR, 2000). There is general lack of data on indoor radon in Kenya especially on building design-traditional versus modern. In rural Kenya traditional mud huts coexist with modern stone building. Indoor radon found to vary widely in Kenya: Mustapha et al (2002): 5-1200 Bqm3, Maina et al (2004): 5-704 Bqm3. None of previous works indicates radon variation with building design. The aim of the current study is to compare radon concentrations in coexisting stone buildings and mud huts. Such data would be useful in formulation of policies regarding housing, as part of radon data base in Kenya Experimental Techniques Characteristic of selected buildings: Traditional Huts: Single roomed, Wall made of wood and plastered using mud, bare floor and no ceiling, grass-thatched or mud plastered, doors and windows remained open during the sampling period. Modern Buildings: (Classes used to represent modern building). Those made of natural stone, wooden floor, ceiling, doors and windows remained shut during the sampling period. Measurement of Radon Concentration Radon sampling was done using Charcoal canisters (EPA type). They were activated, and then exposed simultaneously at sampling sites for 48 hours. Analysis and data acquisition was done using NaI(Tl) gamma-ray spectrometer. Radon concentration was calculated based on gamma rays emitted by 214Pb (295 and 352 keV) and 214Bi (609 keV). 13 Results and Discussion Radon levels were higher in classrooms and significantly high in huts. Mean (Bqm-3 ) Minimum (Bqm-3 ) Maximum (Bqm-3 ). Traditional huts had 170.3 15.6 30.2 315.4 while modern buildings had 193 ±19.3 115.76 257.2. There were higher levels in classroom despite lower levels of 226Ra (50.18 Bqkg-1) in natural stone. Possible source of high concentrations: - radon seeping in through floor boards building up over time as building more closed up - Radon concentration was more varied

  1. Radon and radiation biology of the lung

    International Nuclear Information System (INIS)

    Crameri, R.; Burkart, W.

    1989-01-01

    The main papers presented at the meeting dealt with the behaviour of radon and the indoor environment, radiation biology of the lung, lung dosis and the possible cancer risk caused by radon in homes, contamination of the room air. A series of special papers treated the radon problem in detail: sources and transport mechanisms of radon, geological aspects of the radon radiation burden in Switzerland, radon in homes, search for radon sources, and the Swiss radon-programme RAPROS. 67 figs., 13 tabs., 75 refs

  2. Multivariate signal processing in measurements of radon and radon daughters in air

    International Nuclear Information System (INIS)

    Urbanski, P.; Machaj, B.

    2000-01-01

    Extensive measurements of radon and radon daughters concentration gauge in a radon chamber were carried out. Count rate 'spectra' against time at the output of radiation detectors were measured and registered. The count rate spectra were then processed employing Principal Component Regression (PCR). A root mean square error of the count rate was estimated. It was found that PCR processing removes a great part of count rate random fluctuations originating from the radiation statistics that results in a decrease of count rate random error. The root mean square error of count rate in a radon daughter monitor is about 3 times lower, which is equivalent to the error of the gauge with a 9 times higher air flow rate if no PCR processing is used. In case of the radon concentration gauge the increase of sensitivity is even higher and amounts to 5 times. (author)

  3. Radon measurements in indoor workplaces

    International Nuclear Information System (INIS)

    Tokonami, S.; Matsumoto, M.; Furukawa, M.; Fujimoto, K.; Fujitaka, K.; Pan, J.; Kurosawa, R.

    1996-01-01

    Radon measurements in several office buildings located in Tokyo were carried out with two types of device to study the time-dependent radon concentration in indoor workplaces. Both types of device use the electrostatic field for the collection of 218 Po onto the electrode of the detector. One provides an average radon concentration throughout the day. The other, in which a weekly timer is installed in the circuit of the electrode of the device, provides an average radon concentration during working hours (9:00-17:00, Monday-Friday). Although radon concentrations in Japanese dwellings have been found to be generally low, relatively high concentrations were observed in the office buildings. No consistent seasonal variation was recognised in this study. Little difference of average radon concentrations between working hours and the whole day was found throughout the year in two offices. On the other hand, a significant difference was observed in other offices. The operation of an air conditioner might change the radon concentration during working hours. From the results of radon measurements the average effective dose in the workplace was estimated to be 0.23 mSv for 2000 working hours in a year. (Author)

  4. Radon studies in Indian dwellings

    International Nuclear Information System (INIS)

    Khan, A.J.

    2000-01-01

    The indoor radon ( 222 Rn) concentration has been measured by Solid State Nuclear Track Detectors (SSNTDs) in large number of Indian dwellings. Radon concentrations were measured in different parts of the country. In the first study, radon concentrations were measured in 143 dwellings of Udaipur, Bikaner and Banswara towns of Rajasthan province. The distributions of the time-averaged indoor radon concentration in these three towns of the Rajasthan fit an approximately log normal distribution. The geometric mean (GM) values of radon concentrations in these three places were found to be 74 Bq m -3 , 46 Bq m -3 and 66 Bq m -3 with a geometric standard deviation (GSD) of 2.2, 2.2 and 2.5 respectively. In another study, radon concentrations were measured in about 150 dwellings of hilly regions of the country. The measurements were carried out in Kohima (Nagaland), Baijnath and Palampur (Himachal Pradesh). The distribution of radon concentration in Kohima dwellings was found to be approximately log normal, however, the radon distribution in Baijnath and Palampur dwellings seems to be bimodal. The GM values of the radon concentrations for 65 dwellings in Kohima and 43 dwellings in Baijnath and Palampur were 88 Bq m -3 and 134 Bq m -3 with GSD of 1.7 and 2.5 respectively. The results are discussed in detail. (author)

  5. Radon prevention coating in hot and humid environment

    International Nuclear Information System (INIS)

    Yang Yushan; Dong Faqin; Deng Yuequan; Qu Ruixue

    2013-01-01

    The radon prevention performance of a new self-made radon prevention coating was researched in the radon contamination provided by the releasing radon modules. With coating thickness of 0.8 mm, the radon mitigation efficiency in 1 # radon module concentration is optimal when the addition of defoaming agent is 0.3% (mass fraction). The radon mitigation efficiency increases with the coating thickness when the defoaming agent of 0.3% is added, but the radon mitigation efficiency tends to be stable as the coating thickness is more than 2.0 mm. The radon mitigation efficiency of radon prevention coating appended precipitated barium sulphate decreases obviously, and the addition of ash calcium, white cement and gesso don't decrease radon mitigation efficiency. The addition of white cement and gesso addition affects the radon prevention stability, while radon mitigation efficiency of radon prevention coating with ash calcium keeps a good performance. Under the hot and humid environment, the radon prevention coating still has good radon mitigation efficiency in 2 # radon module concentration. (authors)

  6. 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

  7. Indoor concentrations of radon 222 and its daughters: sources, range, and environmental influences

    International Nuclear Information System (INIS)

    Nero, A.V. Jr.

    1985-04-01

    The author here reviews what is presently known about factors affecting indoor concentrations of radon 222 and its daughters. In US single-family homes, radon concentrations are found to average about 1.5 pCi/1, but substantially higher concentrations occur frequently: perhaps a million US homes have concentrations exceeding 8 pCi/1 (from which occupants receive radiation doses comparable to those now experienced by uranium miners). The major contributor to indoor radon is ordinary soil underlying homes, with this radon being transported indoors primarily by the slight depressurization that occurs toward the bottom of a house interior (due to indoor-outdoor temperature differences and winds). Water from underground sources contributes significantly in a minority of cases, primarily residences with private wells, with public water supplies contributing only a few percent of indoor radon, even when drawn from wells. The strong variability in indoor concentrations is associated primarily with variability in the amount of radon entering homes from these various sources, and secondarily with differences in ventilation rates. However, for a given entry rate, the ventilation rate is the key determinant of indoor concentrations. Human doses are also influenced strongly by the chemical behavior of the daughters (i.e., decay products of radon), and considerable progress has been made recently in investigating a major aspect of this behavior, i.e., the manner in which daughters attach to airborne particles, to walls, and - indeed - to the lining of the lung itself, where the key radiation dose occurs

  8. A calibration facility for radon fluxmeter

    International Nuclear Information System (INIS)

    Li Xianjie; Qiu Shoukang; Zhou Jianliang; Liu Chunkui; Pan Jialin; Yang Mingli

    1998-01-01

    Calibration facilities for radon fluxmeter with three kinds of different emanation medium have been developed. The stability of radon flux is 5%, 9% (RSD) respectively. The uniformity of radon flux is 4.5%, 8.5% (RSD) respectively. These specifications fulfill the calibration requirement for radon fluxmeter. The determination of radon flux of facility takes full account of eliminating the main error source-attenuation effect (including leakage and back diffusion etc.): not only prevent attenuation and make a relevant correction. Therefore the accuracy of determination is assured. The calibration, intercomparison of radon flux meter and the quantitatively evaluation on the measurement method of radon flux are made to be possible by the successful establishment of this facility. (author)

  9. Automatically processed alpha-track radon monitor

    International Nuclear Information System (INIS)

    Langner, G.H. Jr.

    1993-01-01

    An automatically processed alpha-track radon monitor is provided which includes a housing having an aperture allowing radon entry, and a filter that excludes the entry of radon daughters into the housing. A flexible track registration material is located within the housing that records alpha-particle emissions from the decay of radon and radon daughters inside the housing. The flexible track registration material is capable of being spliced such that the registration material from a plurality of monitors can be spliced into a single strip to facilitate automatic processing of the registration material from the plurality of monitors. A process for the automatic counting of radon registered by a radon monitor is also provided

  10. The householders' guide to radon

    International Nuclear Information System (INIS)

    1988-06-01

    This guide is a follow-up to the leaflet Radon in Houses which was issued previously by the Department of the Environment. It is intended for people who live in areas with high levels of radon. It is written particularly for householders whose homes have already been tested and found to have an appreciable level of radon. It explains what radon is, how it gets into houses and what the effects on health may be. It also outlines some of the ways of reducing the level of radon and gives guidance both on how to get the work done and likely costs. (author)

  11. Radon surveys and their implications

    International Nuclear Information System (INIS)

    Miles, J.C.H.; Cliff, K.D.; Dixon, D.W.; Green, B.M.R.; Strong, J.C.

    1989-01-01

    In the UK, as in other countries, radon daughter inhalation is the most significant cause of human exposure to ionising radiation either at home or at work whether one considers the mean or the maximum dose. Substantial studies of radon are under way in the UK, and the importance of radon is recognised in several spheres. NRPB investigations of the radon levels in buildings and mines are reported, the distributions of doses presented and risk factors calculated. The bases of radon limitation for workers and members of the public are given and the means of compliance discussed. (author)

  12. Radon exposure and lung cancer

    International Nuclear Information System (INIS)

    Planinic, J.; Vukovic, B.; Faj, Z.; Radolic, V.; Suveljak, B.

    2003-01-01

    Although studies of radon exposure have established that Rn decay products are a cause of lung cancer among miners, the lung cancer risk to the general population from indoor radon remains unclear and controversial. Our epidemiological investigation of indoor radon influence on lung cancer incidence was carried out for 201 patients from the Osijek town. Ecological method was applied by using the town map with square fields of 1 km 2 and the town was divided into 24 fields. Multiple regression study for the lung cancer rate on field, average indoor radon exposure and smoking showed a positive linear double regression for the mentioned variables. Case-control study showed that patients, diseased of lung cancer, dwelt in homes with significantly higher radon concentrations, by comparison to the average indoor radon level of control sample. (author)

  13. The short-circuit test results of 6.9 kV/2.3 kV 400 kVA-class YBCO model transformer

    International Nuclear Information System (INIS)

    Tomioka, A.; Otonari, T.; Ogata, T.; Iwakuma, M.; Okamoto, H.; Hayashi, H.; Iijima, Y.; Saito, T.; Gosho, Y.; Tanabe, K.; Izumi, T.; Shiohara, Y.

    2011-01-01

    The 6.9 kV/2.3 kV 400 kVA-class single-phase YBCO model transformer with the YBCO tape with copper tape was manufactured for short-circuit current test. Short-circuit test was performed and the short-circuit current of primary winding was 346 A which was about six times larger than the rated current. The I-V characteristics of the winding did not change before and after the test. The transformer withstood short-circuit current. We are planning to turn the result into a consideration of a 66 kV/6.9 kV-20 MVA-class three-phase superconducting transformer. We are developing an elemental technology for 66 kV/6.9 kV 20 MVA-class power transformer with YBCO conductors. The protection of short-circuit technology is one of the elemental technologies for HTS transformer. Since short-circuit current is much higher than critical current of YBCO tape, there is a possibility that superconducting characteristics may be damaged during short-circuit period. We made a conductor to compose the YBCO tape with copper tape. We manufactured 6.9 kV/2.3 kV 400 kVA-class YBCO model transformer using this conductor and performed short-circuit current test. The short-circuit current of primary winding was 346 A which was about six times larger than the rated current. The I-V characteristics of the winding did not change before and after the test. We may consider this conductor withstands short-circuit current.

  14. Radon and radon-daughter concentrations in air in the vicinity of the Anaconda Uranium Mill

    International Nuclear Information System (INIS)

    Momeni, M.H.; Lindstrom, J.B.; Dungey, C.E.; Kisieleski, W.E.

    1979-11-01

    Radon concentration, working level, and meteorological variables were measured continuously from June 1977 through June 1978 at three stations in the vicinity of the Anaconda Uranium Mill with measurements integrated to hourly intervals. Both radon and daughters show strong variations associated with low wind velocities and stable atmospheric conditions, and diurnal variations associated with thermal inversions. Average radon concentration shows seasonal dependence with highest concentrations observed during fall and winter. Comparison of radon concentrations and working levels between three stations shows strong dependence on wind direction and velocity. Radon concentrations and working-level distributions for each month and each station were analyzed. The average maximum, minimum, and modal concentration and working levels were estimated with observed frequencies. The highest concentration is 11,000 pCi/m 3 on the tailings. Working-level variations parallel radon variations but lag by less than one hour. The highest working levels were observed at night when conditions of higher secular radioactive equilibrium for radon daughters exist. Background radon concentration was measured at two stations, each located about 25 km from the mill, and the average is 408 pCi/m 3 . Average working-level background is 3.6 x 10 -3

  15. Method for measurement of radon diffusion and solubility in solid materials

    Science.gov (United States)

    Maier, Andreas; Weber, Uli; Dickmann, Jannis; Breckow, Joachim; van Beek, Patrick; Schardt, Dieter; Kraft, Gerhard; Fournier, Claudia

    2018-02-01

    In order to study the permeation i.e. the diffusion and solubility of radon gas in biological material, a new setup was constructed and a novel analysis was applied to obtain diffusion and solubility coefficients. Thin slabs of solid materials were installed between detector housing and the surrounding radon exposure chamber of 50 Ls volume. In this setup radon can diffuse through thin test samples into a cylindrical volume of 5 mm height and 20 mm diameter and reach an α-particle detector. There the 5.49 MeV α-decay of the penetrating radon atoms is measured by a silicon surface barrier detector. The time dependent activities inside the small detector volume are recorded after injection of a known radon activity concentration into the outer chamber. Analyzing the time behavior of the integral α-activity from radon in the small vessel, both, the diffusion coefficient and solubility of the test material can be determined, based on a new mathematical model of the diffusion process concerning the special boundary conditions given by the experimental setup. These first measurements were intended as proof of concept for the detection system and the data analysis. Thin polyethylene foils (LDPE) were selected as material for the diffusion measurements and the results were in agreement with data from literature. In further measurements, we will concentrate on biological material like bone, fat and other tissues.

  16. Consumer's Guide to Radon Reduction

    Science.gov (United States)

    ... Labs and Research Centers Radon Contact Us Share Consumer's Guide to Radon Reduction: How to Fix Your ... See EPA’s About PDF page to learn more. Consumer's Guide to Radon Reduction: How to Fix Your ...

  17. 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

  18. Radon programme in the Czech Republic

    International Nuclear Information System (INIS)

    Hulka, J.; Thomas, J.

    2003-01-01

    The framework of the Radon programme in the Czech republic includes both precautionary measures and interventions. The programme informally started in early eighties has been now incorporated in national legislation (Atomic Act, Radiation Protection Decree, etc.). Aim of precautionary measures is to avert construction of building above natural radiation guidance levels (200 Bq/m 3 for indoor radon concentration and 0.5 Sv/h for gamma dose rate) by protection of new buildings against soil radon ingress, by regulation of natural radioactivity in building materials and supplied water. Aim of interventions is to identify buildings affected by enhanced natural radioactivity and help owners to put into effect reasonable remedial measures. Two sets of intervention levels for indoor natural exposure were established: guidance intervention levels 400 Bq/m 3 (indoor radon), 1.0 Sv/h (indoor gamma dose rate) and limit values 4000 Bq/m 3 and 10 Sv/h. The radon programme is based both on governmental and private activities. The governmental activities include representative and targeted indoor radon survey, subsidy for radon mitigation, mitigation test measurements and public information on radon issue. The private activities include radon measurement (radon index of building site, indoor measurements, radon diagnosis) and remedial measures. More than 100 commercial companies were authorised by Radiation Protection Authority (SUJB) to provide these measurements

  19. Radon survey techniques

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The report reviews radon measurement surveys in soils and in water. Special applications, and advantages and limitations of the radon measurement techniques are considered. The working group also gives some directions for further research in this field

  20. Comparison of retrospective and contemporary indoor radon measurements in a high-radon area of Serbia

    International Nuclear Information System (INIS)

    Zunic, Z.S.; Yarmoshenko, I.V.; Kelleher, K.; Paridaens, J.; Mc Laughlin, J.P.; Celikovic, I.; Ujic, P.; Onischenko, A.D.; Jovanovic, S.; Demajo, A.; Birovljev, A.; Bochicchio, F.

    2007-01-01

    In Niska Banja, Serbia, which is a high-radon area, a comparison was made between two retrospective radon measuring methods and contemporary radon measurements. The two retrospective methods derive the radon concentrations that occurred in dwellings over longer periods in the past, based on the amount of trapped 210 Po on the surface of glass objects (surface traps, ST) or in the bulk of porous materials (volume traps, VT). Both surface implanted 210 Po in glass objects and contemporary radon in air were measured in 46 rooms, distributed in 32 houses of this radon spa-town, using a dual alpha track detector configuration (CR-39 and LR115) and CR-39 track etched detectors, respectively. In addition to the use of surface trap measurements, in 18 rooms (distributed in 15 houses) VT samples of suitable material were also collected, allowing to compare ST and VT retrospective radon concentration estimates. For each room, contemporary annual radon concentrations (CONT) were measured or estimated using seasonal correction factors. The distribution of the radon concentration in all data sets was found to be close to lognormal (Chi-square test > 0.05). Geometric means (GM) are similar, ranging from 1040 to 1380 Bq m -3 , whereas geometric standard deviations (GSD) for both the retrospective methods are greater than for the CONT method, showing reasonable agreement between VT, ST and CONT measurements. A regression analysis, with respect to the lognormal distribution of each data set, shows that for VT-ST the correlation coefficient r is 0.85, for VT-CONT r is 0.82 and for ST-CONT r is 0.73. Comparison of retrospective and contemporary radon concentrations with regard to supposed long-term indoor radon changes further supports the principal agreement between the retrospective and conventional methods

  1. 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...

  2. Quality assurance for radon measurements in Germany

    International Nuclear Information System (INIS)

    Beck, T.R.; Buchroeder, H.; Foerster, E.; Schmidt, V.

    2005-01-01

    Full text: Radiation protection regarding work activities at workplaces with naturally occurring radiation has been regulated in the German Radiation Protection Ordinance. Regulations refer only to workplaces where the presence of natural radiation leads to a significant increase in the exposure of workers. These workplaces were identified in the following working areas with enhanced exposures to radon-222: underground mines, including visitor mines and show caves; radon-spas and galleries; water supply and distribution industries. Presently, regulations are being initiated by the German government to limit the exposures to radon in homes. For radon measurements at workplaces passive radon devices for individual monitoring as well as active measuring systems for workplace monitoring can be used. However, passive radon devices are preferred for radon measurements in homes because of low costs and availability in large quantities. To assure the quality of radon measurements the German Federal Office for Radiation Protection (BfS) has established annual interlaboratory comparisons for passive radon devices. The comparisons are carried out in the BfS radon calibration laboratory accredited by the German Calibration Service. Passive radon devices which use solid state track detectors, electrets or activated charcoal can be submitted. Approved radon services which offer radon measurements to determine radon exposure in homes and at workplaces have to pass the comparisons successfully. (author)

  3. Metrology of the radon in air volume activity at the italian radon reference chamber

    Energy Technology Data Exchange (ETDEWEB)

    Sciocchetti, G.; Cotellessa, G.; Soldano, E.; Pagliari, M. [Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti, ENEA Centro Ricerche Casaccia Roma (Italy)

    2006-07-01

    The approach of the Italian National Institute of Ionising Radiations (I.N.M.R.I.-ENEA) on radon metrology has been based on a complete and integrated system which can be used to calibrate the main types of {sup 222}Rn in air measuring instruments with international traceability. The Italian radon reference chamber is a research and calibration facility developed at the Casaccia Research Center in Roma. This facility has an inner volume of one m{sup 3}. The wall is a cylindrical stainless steel vessel coupled with an automated climate apparatus operated both at steady and dynamic conditions. The control and data acquisition equipment is based on Radotron system, developed to automate the multitasking management of different sets of radon monitors and climatic sensors. A novel approach for testing passive radon monitors with an alpha track detector exposure standard has been developed. It is based on the direct measurement of radon exposure with a set of passive integrating monitors based on the new ENEA piston radon exposure meter. This paper describes the methodological approach on radon metrology, the status-of-art of experimental apparatus and the standardization procedures. (authors)

  4. Metrology of the radon in air volume activity at the italian radon reference chamber

    International Nuclear Information System (INIS)

    Sciocchetti, G.; Cotellessa, G.; Soldano, E.; Pagliari, M.

    2006-01-01

    The approach of the Italian National Institute of Ionising Radiations (I.N.M.R.I.-ENEA) on radon metrology has been based on a complete and integrated system which can be used to calibrate the main types of 222 Rn in air measuring instruments with international traceability. The Italian radon reference chamber is a research and calibration facility developed at the Casaccia Research Center in Roma. This facility has an inner volume of one m 3 . The wall is a cylindrical stainless steel vessel coupled with an automated climate apparatus operated both at steady and dynamic conditions. The control and data acquisition equipment is based on Radotron system, developed to automate the multitasking management of different sets of radon monitors and climatic sensors. A novel approach for testing passive radon monitors with an alpha track detector exposure standard has been developed. It is based on the direct measurement of radon exposure with a set of passive integrating monitors based on the new ENEA piston radon exposure meter. This paper describes the methodological approach on radon metrology, the status-of-art of experimental apparatus and the standardization procedures. (authors)

  5. Radon survey in Metropolitan Toronto schools

    International Nuclear Information System (INIS)

    Becker, E.; Moridi, R.

    1992-01-01

    The radon testing survey in Metropolitan Toronto public schools was the most intensive project of its kind ever undertaken in Canadian schools. It also included an extensive public education program on radiation and radon-in-schools. The radon levels at 632 schools were measured using the CAIRS Radon Monitors. Ninety percent of the locations measured were found to have a radon level equal to or less than 2 mWL. Two locations in two different schools were found to have a radon level at or above the Action Level (20 mWL). The remaining results were between the two extremes. Follow-up testing in those schools where more than 10 mWL of radon was found is in progress. (author)

  6. Radon Survey in Hospitals in Slovenia

    International Nuclear Information System (INIS)

    Vaupotic, J.

    2003-01-01

    In Slovenia, several radon studies at workplaces have been carried out in last years, supported by the Ministry of Education, Science and Sport, and the Ministry of Health. After radon surveys in kindergartens, schools and homes, within which about 2600 buildings were checked for radon and which provided the level of radon problem in the country, next investigations were focused on the workplaces with potentially higher radon risk. Hence, in the Postojna Cave permanent radon monitoring was introduced in 1995 and comprehensive radon studies were performed: in 5 bigger spas during 1996-1998, in major waterworks and wine cellars in 2001, and in major Slovene hospitals in 2002. This paper reports the results of radon study in 26 major Slovene hospitals, comprising radon concentrations in 201 rooms and dose estimates for 1025 persons working in these rooms. Radon survey in 201 rooms of 26 major hospitals in Slovenia revealed only 7 rooms in which monthly average radon concentration in the indoor air exceeded 400 Bqm -3 . Generally, concentrations in basement were on average for about 30% higher than in ground floor, although exceptionally high values have also been found in the ground floor. For 966 persons (94.2%) of the total of 1025 persons working in the rooms surveyed, the annual effective dose, estimated according to the Basic Safety Standards was below 1 mSv, while for 59 it exceeded 1 mSv. In 7 rooms with more than 400 Bqm -3 in which 16 persons receive between 2.1 and 7.3 mSv per year radon monitoring is continued. (author)

  7. Radon: Residential attitudes toward the risk

    International Nuclear Information System (INIS)

    Fort, R.; Hinman, G.; Rosenman, R.; Wandschneider, P.

    1990-01-01

    Veradale, Washington (east of Spokane) is a region of high residential radon concentrations. Three hundred eighty residents of Veradale recently responded to a mail survey designed to elicit (1) their knowledge of and attitudes toward the risks of radon in their homes, (2) the actions they have taken or intend to take to identify and reduce those risks, and (3) policy preferences toward radon. Results reveal that these residents know that they live in an area with high radon levels, that radon causes lung cancer, and that radon will affect their health. However only 11% of respondents have had their homes tested for radon. This especially is puzzling because a large number of respondents claimed that (1) radon was important in home buying decisions, (2) they would test their own homes, (3) they would take action if such tests revealed problems, and (4) their willingness to pay for tests and improvements was well within the current costs of these actions. It remains a mystery why testing is at such a low level. Three other results are of note. First, subsidies for radon tests and home improvements may be having the unintended consequences of unneeded improvements and (potentially) moves without improvements. Second, individuals want radon testing required and results made known during home purchase decisions. Third, at present, weatherization programs that concentrate radon are acceptable to individuals. Of course, the future may hold different results. Administrators of weatherization programs, who are trusted by respondents according to this survey, would do well to institute weatherization programs with reduced radon concentrations in mind

  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. THE REPUBLIC OF BELARUS RADON DANGER MAP

    Directory of Open Access Journals (Sweden)

    L. A. Chunikhin

    2016-01-01

    Full Text Available Radon is the major contributor to the background exposure of the population. In the world practice, the radon risk or radon potential mapping are used for the radon dose assessment.The aim of this work was a radon danger mapping of the Republic of Belarus to assess the radiation situation and determine the radon hazard critical areas.Materials and methods: The mapping is based on measured values of radon volume activity in the living rooms of different buildings on the territory of the six regions of the Republic of Belarus. We have performed more than 4000 measurements. Integral track radon radiometers based on the polymer Kodak LR-115 film were used to evaluate radon volume activity. Exposure time ranged from 90 to 120 days. The cartogram was built with using the MAPINFO software package.Results: The low levels of radon concentrations were determined in the Brest and Gomel regions, as well as in the southern districts of Minsk and south-western districts of the Mogilev region. The high levels radon concentrations were determined in some districts of the Vitebsk and Grodno regions, as well as in the north-eastern districts of the Mogilev region. About 2–5 times nonuniformity of radon distribution in settlements of the Republic was observed. The radon hazard critical areas with radon concentrations in the range of 200–400 Bq/m3 were found in some districts of the Vitebsk, Grodno and Mogilev regions.Conclusions: The radon risk map of the Republic of Belarus gives the possibility to estimate the existing radiation risk. Taking into account the low efficiency of countermeasures long after the Chernobyl accident, it is necessary to increase the level of radiation protection through the radon mitigation activities or to change the radon normative documents.

  10. Indoor radon concentration in Poland

    International Nuclear Information System (INIS)

    Mamont-Ciesla, K.; Jagielak, J.; Rosinski, S.W.; Sosinka, A.; Bysiek, M.; Henschke, J.

    1996-01-01

    Preliminary survey of Rn concentration indoors by means of track detectors and y-ray dose rate with the use of TLD in almost 500 homes in selected areas of Poland was performed in the late 1980s. It was concluded that radon contributes 1.16 mSv i.e. about 46 per cent of the total natural environment ionizing radiation dose to the Polish population. Comparison of the average radon concentrations in 4 seasons of a year and in 3 groups of buildings: masonry, concrete and wood, revealed that the ground beneath the building structure is likely the dominant source of radon indoors. Since the National Atomic Energy Agency in its regulations of 1988-03-31 set up the permissible limit of the equilibrium equivalent concentration of radon in new buildings (equal 100 Bq/m3), the nation-scale survey project for radon in buildings has been undertaken. These regulations were supposed to take effect in 1995-01-01. The project has 3 objectives: to estimate the radiation exposure due to radon daughters received by Polish population to identify radon-prone areas in Poland to investigate dependence of the indoor radon concentrations on such parameters as: type of construction material, presence (or absence) of cellar under the building, number of floor

  11. 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

  12. Accurate measurement of indoor radon concentration using a low-effective volume radon monitor

    International Nuclear Information System (INIS)

    Tanaka, Aya; Minami, Nodoka; Mukai, Takahiro; Yasuoka, Yumi; Iimoto, Takeshi; Omori, Yasutaka; Nagahama, Hiroyuki; Muto, Jun

    2017-01-01

    AlphaGUARD is a low-effective volume detector and one of the most popular portable radon monitors which is currently available. This study investigated whether AlphaGUARD can accurately measure the variable indoor radon levels. The consistency of the radon-concentration data obtained by AlphaGUARD is evaluated against simultaneous measurements by two other monitors (each ∼10 times more sensitive than AlphaGUARD). When accurately measuring radon concentration with AlphaGUARD, we found that the net counts of the AlphaGUARD were required of at least 500 counts, <25% of the relative percent difference. AlphaGUARD can provide accurate measurements of radon concentration for the world average level (∼50 Bq m -3 ) and the reference level of workplace (1000 Bq m -3 ), using integrated data over at least 3 h and 10 min, respectively. (authors)

  13. 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

  14. Contribution of waterborne radon to home air quality

    International Nuclear Information System (INIS)

    Deb, A.K.

    1994-01-01

    Radon-222 is a member of the uranium decay chain and is formed from the decay of radium-226. Radon and its decay products emit alpha particles during the decay process. If radon is inhaled, alpha particles emitted from inhaled radon and its daughters increase the risk of lung cancer. Radon is soluble in water; thus when radon comes in contact with groundwater it dissolves. The radon concentration in groundwater may range from 100 pCi/L to 1,000,000 pCi/L. When water with a high radon level is used in the home, radon is released from the water to the air and thus can increase indoor air radon concentration. Considering the estimated health risk from radon in public water supply systems, EPA has proposed a maximum contaminant level (MCL) of 300 pCi/L for radon in public drinking water supplies. To address the health risks of radon in water and the proposed regulations, the American Water Works Association Research Foundation (AWWARF) initiated a study to determine the contribution of waterborne radon to radon levels in indoor household air

  15. Radon in Croatian spas

    International Nuclear Information System (INIS)

    Radolic, V.; Vukovic, B.; Planinic, J.

    2004-01-01

    There are ten thermal spas in Croatia and all of them provide health services for patients and visitors. Radon measurements were performed since there is a lack of data concerning natural radioactivity originated from radon and its short-lived progenies in such environments. The thermal water at two different sites (the indoor swimming pool with geothermal water and the spring) in each spa was sampled and radon concentrations were measured by AlphaGUARD radon measuring system. The obtained values were in the range of 0.7 to 19 Bq.dm -3 and 2 to 94 Bq.dm -3 for indoor swimming pools and springs, respectively. Integrated measurements of radon concentration in air were performed by two solid state nuclear track detectors LR-115 II (open and diffusion one) thus enabling estimation of equilibrium factor between radon and its daughters. The annual effective doses received by spa workers were found to be about 1 mSv/y (below the lower limit value of 3 mSv/y recommended by ICRP 65). The doses of patients and visitors were one or two order of magnitude lower than that of the personnel. (author)

  16. Statistical analysis of real-time, enviromental radon monitoring results at the Fernald Enviromental Management Project

    International Nuclear Information System (INIS)

    Liu, Ning; Spitz, H.B.; Tomezak, L.

    1996-01-01

    A comprehensive real-time, environmental radon monitoring program is being conducted at the Fernald Environmental Management Project, where a large quantity of radium-bearing residues have been stored in two covered earth-bermed silos. Statistical analyses was conducted to determine what impact radon emitted by the radium bearing materials contained in the silos has on the ambient radon concentration at the Fernald Environmental Management Project site. The distribution that best describes the outdoor radon monitoring data was determined before statistical analyses were conducted. Random effects associated with the selection of radon monitoring locations were accommodated by using nested and nested factorial classification models. The Project site was divided into four general areas according to their characteristics and functions: (1) the silo area, where the radium-bearing waste is stored; (2) the production/administration area; (3) the perimeter area, or fence-line, of the Fernald Environmental Management Project site; and (4) a background area, located approximately 13 km from the Fernald Environmental Management Project site, representing the naturally-occurring radon concentration. A total of 15 continuous, hourly readout radon monitors were installed to measure the outdoor radon concentration. Measurement results from each individual monitor were found to be log-normally distributed. A series of contrast tests, which take random effects into account, were performed to compare the radon concentration between different areas of the site. These comparisons demonstrate that the radon concentrations in the production/administration area and the perimeter area are statistically equal to the natural background, whereas the silo area is significantly higher than background. The study also showed that the radon concentration in the silo area was significantly reduced after a sealant barrier was applied to the contents of the silos. 10 refs., 6 figs., 8 tabs

  17. Chemical properties of radon

    International Nuclear Information System (INIS)

    Stein, L.

    1986-01-01

    Radon is frequently regarded as a totally inert element. It is, however, a ''metalloid'' - an element which lies on the diagonal of the Periodic Table between the true metals and nonmetals and which exhibits some of the characteristics of both. It reacts with fluorine, halogen fluorides, dioxygenyl salts, fluoro-nitrogen salts, and halogen fluoride-metal fluoride complexes to form ionic compounds. Several of the solid reagents can be used to collect radon from air but must be protected from moisture, since they hydrolyze readily. Recently, solutions of nonvolatile, cationic radon have been produced in nonaqueous solvents. Ion-exchange studies have shown that the radon can be quantitatively collected on columns packed with either Nafion resins or complex salts. In its ionic state, radon is able to displace H + , Na + , K + , Cs + , Ca 2+ , and Ba 2+ ions from a number of solid materials. 27 refs., 6 figs

  18. The radon: evaluation and risk management; Le radon: evaluation et gestion du risque

    Energy Technology Data Exchange (ETDEWEB)

    Lacoste, A.C. [Direction Generale de la Surete Nucleaire et de la Radioprotection, 75 - Paris (France); Masse, R. [Academie des Technologies, 75 - Paris (France); Aurengo, A. [Hopital Pitie-Salpetriere, Service de Medecine Nucleaire, 75 - Paris (France); Erich Wichmann, H. [Neuberberg Munich Univ. (Germany); Timarche, M.; Laurier, D.; Robe, M.Ch. [Institut de Radioprotection et de Surete Nucleaire (IRSN), 92 - Clamart (France); Baubron, J.C.; Bonijoly, D. [BRGM, 75 - Paris (France); Collignan, B. [Centre Scientifique et Technique du Batiment, (CSTB), 75 - Paris (France); Berrier, H. [Direction Gle de l' Urbanisme de l' Habitat et de la Construction, 75 - Paris (France); Jaouen, J. [Direction Departementale des Affaires Sanitaires et Sociales de la Haute-Vienne (France); Caamano, D. [Direction Departementale des Affaires Sanitaires et Sociales de l' Essonne, 91 (France); Guiot, F. [Direction Departementale des Affaires Sanitaires et Sociales de la Haute-Marne (France); Grall, B. [Direction Departementale des Affaires Sanitaires et Sociales de Bretagne (France); Frutos Vasquez, B.; Olaya Adan, M. [Istituto de Ciencias de la Construction (Italy); Garcia Cadierno, J.P.; Martin Matarranz, J.L.; Serrano Renedo, J.; Suarez Mahou, E. [Consejo de Seguridad Nuclear, Madrid (Spain); Fernandez, J.A. [ENUSA Industrias Avanzadas (Spain); Mjones, L.; Pirard, P. [Institut de veille sanitaire, 94415 - Saint-Maurice (France); Godet, J.L.; Rougy, Ch. [Direction Gle de la Surete Nucleaire et de la Radioprotection, 75 - Paris (France)

    2003-06-15

    The radon exposure constitutes for the French population the first cause of natural irradiation among the different natural sources of irradiation. It is possible to have a significant action on it, either by making draught proof in order to avoid to radon to get inside houses, either by ventilating in order to dispel the radon and improve air quality. (N.C.)

  19. Radon in large buildings

    International Nuclear Information System (INIS)

    Wilson, D.L.; Dudney, C.S.; Gammage, R.B.

    1993-01-01

    Over the past several years, considerable research has been devoted by the U.S. Environmental Protection Agency (USEPA) and others to develop radon sampling protocols for single family residences and schools. However, very little research has been performed on measuring radon in the work place. To evaluate possible sampling protocols, 833 buildings throughout the United States were selected for extensive radon testing. The buildings tested (warehouses, production plants and office buildings) were representative of commercial buildings across the country both in design, size and use. Based on the results, preliminary radon sampling protocols for the work place have been developed. (orig.). (5 refs., 3 figs.)

  20. Radon dose and aerosols

    International Nuclear Information System (INIS)

    Planinic, J.; Radolic, V.; Faj, Z.; Vukovic, B.

    2000-01-01

    The equilibrium factor value (F) was measured in the NRPB radon chamber and the corresponding track density ratio (r = D/D 0 ) of bare (D) and diffusion (D 0 ) LR-115 nuclear track detectors was determined, as well as the regression equation F(r). Experiments with LR-115 nuclear track detectors and aerosol sources (burning candle and cigarette) were carried out in the Osijek University radon chamber and afterwards an empirical relationship between the equilibrium factor and aerosol concentration was derived. For the purpose of radon dose equivalent assessment, procedures for determining the unattached fraction of radon progeny were introduced using two nuclear track detectors. (author)

  1. Radon remediation of a two-storey UK dwelling by active sub-slab depressurization: observations on hourly Radon concentration variations

    International Nuclear Information System (INIS)

    Denman, A.R.

    2008-01-01

    Radon concentration levels in a two-storey detached single-family dwelling in Northamptonshire, UK, were monitored at hourly intervals throughout a 5-week period during which sub-slab depressurization remediation measures, including an active sump system, were installed. Remediation of the property was accomplished successfully, with the mean radon levels upstairs and downstairs greatly reduced and the prominent diurnal variability in radon levels present prior to remediation almost completely removed. Following remediation, upstairs and downstairs radon concentrations were 32% and 16% of their pre-remediation values respectively. The mean downstairs radon concentration was lower than that upstairs, with pre-and post-remediation values of the upstairs/downstairs concentration ratio, R U/D , of 0.93 and 1.76 respectively. Cross-correlation between upstairs and downstairs radon concentration time-series indicates a time-lag of the order of 1 hour or less, suggesting that diffusion of soil-derived radon from downstairs to upstairs either occurs within that time frame or forms a relatively insignificant contribution to the upstairs radon level. Cross-correlation between radon concentration time-series and the corresponding time-series for local atmospheric parameters demonstrated correlation between radon concentrations and internal/external pressure-difference prior to remediation. This correlation disappears following remediation, confirming the effectiveness of the remediation procedure in mitigating radon ingress from the ground via the stack-effect. Overall, these observations provide further evidence that radon emanation from building materials makes a not insignificant contribution to radon concentration levels within the building. Furthermore, since this component remains essentially unaffected by sub-slab depressurization, its proportional contribution to the total radon levels in the home increases following remediation, leading to the conclusion that where

  2. 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

  3. Radon and radon-daughter concentrations in air in the vicinity of the Anaconda Uranium Mill

    Energy Technology Data Exchange (ETDEWEB)

    Momeni, M H; Lindstrom, J B; Dungey, C E; Kisieleski, W E

    1979-11-01

    Radon concentration, working level, and meteorological variables were measured continuously from June 1977 through June 1978 at three stations in the vicinity of the Anaconda Uranium Mill with measurements integrated to hourly intervals. Both radon and daughters show strong variations associated with low wind velocities and stable atmospheric conditions, and diurnal variations associated with thermal inversions. Average radon concentration shows seasonal dependence with highest concentrations observed during fall and winter. Comparison of radon concentrations and working levels between three stations shows strong dependence on wind direction and velocity. Radon concentrations and working-level distributions for each month and each station were analyzed. The average maximum, minimum, and modal concentration and working levels were estimated with observed frequencies. The highest concentration is 11,000 pCi/m/sup 3/ on the tailings. Working-level variations parallel radon variations but lag by less than one hour. The highest working levels were observed at night when conditions of higher secular radioactive equilibrium for radon daughters exist. Background radon concentration was measured at two stations, each located about 25 km from the mill, and the average is 408 pCi/m/sup 3/. Average working-level background is 3.6 x 10/sup -3/.

  4. An investigation into the knowledge and attitudes towards radon testing among residents in a high radon area

    International Nuclear Information System (INIS)

    Clifford, Susan; Menezes, Gerard; Hevey, David

    2012-01-01

    The aim of this study was to investigate the knowledge and attitudes of residents in the Castleisland area to radon. Castleisland in Co. Kerry was described as a high radon area following the discovery of a house in the area with radon levels 245 times that of the national reference level. Residents in this area were then asked to measure their homes for radon in the Castleisland radon survey. The uptake of this measurement was 17%. In order to investigate this response rate further, a questionnaire was designed and distributed to residents in the Castleisland area. This questionnaire measured the testing history of the participants, the reasons for testing/not testing, the factors important to them when considering having their home tested, radon knowledge and finally intentions to measure their home for radon. It was found that the main reason people do not test their home for radon is that they believe their home does not have a problem. Optimistic bias was thought to play a role here. The subjective norm component of the theory of planned behaviour was found to have a significant independent contribution in the variation in intentions to measure one’s home for radon and this in turn could be targeted to increase uptake of radon measurement in the future. (note)

  5. Radon in dwellings the national radon survey Clare, Limerick and Tipperary

    International Nuclear Information System (INIS)

    McGarry, A.T.; Fennell, S.G.; Mackin, G.M.; Madden, J.S.; O'Colmain, M.

    1998-12-01

    This report presents the results of the fourth phase of the National Radon Survey carried out by the Radiological Protection Institute of Ireland. The counties included in this phase are Clare, Limerick and Tipperary. The average radon concentrations for the houses measured in these counties were 88 Bq/m 3 , 77 Bq/m 3 and 79 Bq/m 3 . The measurement data were grouped on the basis of the 10 km grid squares of the Irish National Grid System and used to predict the percentage of dwellings in each grid square which exceeds the Reference Level of 200 Bq/m 3 . Grid squares where this percentage is predicted to be 10% or higher are designated High Radon Areas. The health effects of exposure to high radon levels are discussed and recommendations are made regarding both new and existing dwellings. (author)

  6. Environmental Concentration of Radon and Radon Progeny in a Nuclear Facility in a Decommissioning Stage

    International Nuclear Information System (INIS)

    Ramirez, M. P.; Correa, E.; Sancho, C.

    1999-01-01

    According to the new European Directive 96/29/EURATOM the radiological risk due to natural radionuclides must be consider and the pertinent periodic control must be realized. During the works performed at CIEMAT an estimation of the effective average doses due to Radon inhalation in work places of the installation have been performed. Radon and Radon progeny concentration has been measured in continuous joint whit the meteorological conditions as temperature, pressure and relative humidity. Two different equipment has been used: Alpha-guard whit ionization chamber detector and Eda-wlm-300 whit a semiconductor detector. A passive Radon detector, E-perm has been simultaneously used in the monitoring system. The results obtained during the measuring of Radon and Radon progeny concentrations indoors and estimation of doses have been analyzed and are presented in the paper. (Author) 11 refs

  7. Radon remediation in irish schools

    International Nuclear Information System (INIS)

    Synnott, H.

    2006-01-01

    Full text: Commencing in 1998, the Radiological Protection Institute of Ireland carried out radon measurements in 3826 schools in the Republic of I reland on behalf of the Irish Department of Education and Science (D.E.S.). This represents approximately 97% of all schools in the country. Approximately 25% (984) schools had radon concentrations above the Irish national schools Reference Level for radon of 200 Bq/m 3 and required remedial work. The number of individual rooms with radon concentrations above 200 Bq/m 3 was 3020. Remedial work in schools commenced in early 2000. In general schools with maximum radon concentrations in the range 200 -400 Bq/m 3 in one or more rooms were remediated through the installation of passive systems such as an increase in permanent background ventilation mainly wall vents and trickle vents in windows. Schools with maximum radon concentrations greater than 400 Bq/m 3 were usually remediated through the provision of active systems mainly fan assisted sub -slab de pressurization or where this was not possible fan assisted under floor ventilation. The cost of the remedial programme was funded by central Government. Active systems were installed by specialized remedial contractors working to the specifications of a radon remedial expert appointed by the D.E.S. to design remedial systems for affected schools. Schools requiring increased ventilation were granted aided 190 pounds per affected room and had to organize the work themselves. In most schools radon remediation was successful in reducing existing radon concentrations to below the Reference Level. Average radon concentration reduction factors for sub-slab de pressurization systems and fan assisted fan assisted under floor ventilation ranged from 5 to 40 with greater reduction rates found at higher original radon concentrations. Increasing ventilation in locations with moderately elevated radon concentrations (200 - 400 Bq/m 3 ) while not as effective as active systems produced on

  8. Radon risk communication research: Practical lessons

    International Nuclear Information System (INIS)

    Fisher, A.; Johnson, F.R.

    1990-01-01

    Those responsible for state and local radon programs often express frustration about the small share of homes that have been tested for radon, and the small share of those with high readings that have been mitigated. There are now a number of completed studies that have examined how well alternative ways of communicating about radon risk have accomplished the goals of motivating appropriate testing and mitigation. This paper summarizes the research results that are most crucial for planning and implementing effective radon risk communication programs. We identify six reasons why people do not respond to radon as a serious threat and provide some remedies suggested by radon studies

  9. Radon classification of building ground

    International Nuclear Information System (INIS)

    Slunga, E.

    1988-01-01

    The Laboratories of Building Technology and Soil Mechanics and Foundation Engineering at the Helsinki University of Technology in cooperation with The Ministry of the Environment have proposed a radon classification for building ground. The proposed classification is based on the radon concentration in soil pores and on the permeability of the foundation soil. The classification includes four radon classes: negligible, normal, high and very high. Depending on the radon class the radon-technical solution for structures is chosen. It is proposed that the classification be done in general terms in connection with the site investigations for the planning of land use and in more detail in connection with the site investigations for an individual house. (author)

  10. Studying the possibility of recharging E-Perm for radon measurement in air

    International Nuclear Information System (INIS)

    Shweikani, R.; Bardan, R.

    2011-03-01

    In this work recharging electret detectors and studying their responding for radioactive gases (radon gas) was studied and the results were compared with solid state nuclear detectors (CR-39). After several experiments we found that using a metal nozzle which is connected to a high voltage supply (poling method) was useful to polarize the electret material and get a stable electrostatic charge. The stability of electret was studied after each experiment ,the results showed that the best charging parameters were: (7 mm as a nozzle height.- 15 sec as a charging time.- 5 kV as a charging voltage). Depending on the charging and stability studying results the electrets were calibrated in radon calibration cell and the calibration factors were defined The charged electrets were examined to measure radon concentration in the open environmental and were compared with CR-39 detectors; the charged electrets appeared a liner response for radon gas as CR-39 detectors.(author)

  11. 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)

  12. Investigation of radon level in Chongqing

    International Nuclear Information System (INIS)

    Pan Chunzhen; Liu Jialie; Du Hengyan; Wang Ling; Li Yiwei

    2009-01-01

    Contents of radon in air in the urban district, building fields,diggings and hotel in Chongqing were investigated. Result shows that the mean concentration of radon is 10.8 Bq/m 3 in air in the urban district, and the mean concentration of radon is 1193 Bq/m 3 in soils on building fields. Radon level is obviously different in each of diggings, with the highest being in fluorite mine and the second in plumbum and zinc mine. The statistical mean value of radon concentration of 10 typles of diggings investigated is 65.2 Bq/m 3 , while the mean concentration of radon in fluorite mine is 369 Bq/m 3 , which is 35 times higher than in the urban area. The mean concentration of radon is 32.9 Bq/m 3 in eight hotels. (authors)

  13. Indoor radon concentration and its possible dependence on ventilation rate and flooring type

    International Nuclear Information System (INIS)

    Ashok, G. V.; Nagaiah, N.; Shiva Prasad, N. G.

    2012-01-01

    The results of radon concentration measurements carried out in dwellings with natural ventilation for 1 y in Bangalore are reported. Measurements, covering three sessions of the day (morning, afternoon, night) were performed two times in a month for 1 y at a fixed place of each dwelling at a height of 1 m above the ground surface in selected dwellings. The low-level radon detection system (LLRDS), an active method, was used for the estimation of radon concentration. The measurements were aimed to understand the diurnal variation and the effect of ventilation rate and flooring type on indoor radon concentration. The geometric mean (±geometric standard deviation) of indoor radon concentration from about 500 measurements carried out in 20 dwellings is found to be 25.4 ±1.54 Bq m -3 . The morning, afternoon and night averages were found to be 42.6 ±2.05, 15.3 ±2.18 and 28.5 ±2.2 Bq m -3 , respectively. The approximate natural ventilation rates of the dwellings were calculated using the PHPAIDA-the on-line natural ventilation, mixed mode and air infiltration rate calculation algorithm and their effects on indoor radon concentrations were studied. The inhalation dose and the lung cancer risk due to indoor radon exposure were found to be 0.66 mSv y -1 and 11.9 per 10 6 persons, respectively. The gamma exposure rate was also measured in all the dwellings and its correlation with the inhalation dose rate was studied. (authors)

  14. 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

  15. 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

  16. Radon Concentration in Caves of Croatia - Assesing Effective Radon Doses for Occupational Workers and Visitors

    International Nuclear Information System (INIS)

    Radolic, V.; Miklavcic, I.; Poje, M.; Stanic, D.; Vukovic, B.; Paar, D.

    2011-01-01

    Radon monitoring at potentially highly radioactive location such as caves is important to assess the radiological hazards to occupational workers and occasional visitors. In its Publication 65 the ICRP has produced recommendations dealing with exposure to elevated background radiation, in particular, the risk associated with the inhalation of radon and radon progeny. Recommended annual effective dose from radon 222Rn and its short-lived progeny for workers should not exceed 20 mSv and for occasional users (visitors) the same recommendation is 1 mSv. Measurements were performed with series of track etched detectors (LR115 - type II) in several caves in Croatia. The obtained values for the radon concentration ranged from ambient values up to several thousand Bq m -3 . Radon concentration was measured in about 20 caves of Velebit and Zumberak mountains and the highest radon concentration was in Lubuska jama (3.8 kBq m -3 ) and cave Dolaca (21.8 kBq m -3 ), respectively. Djurovica cave is especially interesting because of its huge tourist potential due to its location bellow Dubrovnik airport. Its mean annual radon concentration of 17.6 kBq m -3 classifies Djurovica cave among caves with high radon concentration. A visitor during half an hour visit at summer time would receive an effective dose of 30.6 μSv. Calculated mean dose rate of 44 μSv/h means that workers (mainly tourist guides) should limit their time inside cave to 454 hours per year. Manita pec is the only cave open for tourists on the territory of Paklenica National Park. The preliminary radon measurements performed during summer 2010, gave an average radon concentration of 1.1 kBq m -3 . An exposure to average dose rate of 3.7 μSv/h means that the tourist guides would receive an effective dose of 0.42 mSv during summer period according to their working schedule. A visitor during half an hour visits would receive an effective dose of 1.86 μSv. (author)

  17. Two-dimensional electrophoretic analysis of transformation-sensitive polypeptides during chemically, spontaneously, and oncogene-induced transformation of rat liver epithelial cells

    DEFF Research Database (Denmark)

    Wirth, P J; Luo, L D; Fujimoto, Y

    1992-01-01

    ; AFB), spontaneously, and oncogene (v-Ha-ras, v-raf, and v-myc/v-raf)-induced transformation of RLE cells. Two-dimensional mapping of [35S]methionine-labeled whole cell lysate, cell-free in vitro translation products and [32P]orthophosphate-labeled polypeptides revealed subsets of polypeptides specific...... for each transformation modality. A search of the RLE protein database indicated the specific subcellular location for the majority of these transformation-sensitive proteins. Significant alterations in the expression of the extracellular matrix protein, fibronectin, as well as tropomyosin......- and intermediate filament-related polypeptides (vimentin, beta-tubulin, the cytokeratins, and actin) were observed among the various transformant cell lines. Immunoprecipitation and Western immunoblot analysis of tropomyosin expression in four individual AFB-, as well as four spontaneously induced, and each...

  18. Measurement of the radon exhalation rate from the medium surface by tracing the radon concentration

    International Nuclear Information System (INIS)

    Yanliang Tan; Detao Xiao

    2013-01-01

    The paper will present a method based on the accumulation chamber technique for measuring of radon exhalation from the medium surface. A radon monitor traces the change of radon concentration in the accumulation chamber, and then the radon exhalation can be obtained accurately through linear fit. Based on our recent experiments, the radon exhalation rate from the medium surface obtained from this method is in good agreement with the actual exhalation rate of our simulation facility. This method is superior to the competition method which obtains the radon exhalation through the exponential fit by an external PC-system. The calculation for the exponential fit is very easy by computer and related software. However, for portable instruments, the single chip microcomputer can't calculate the exponential fit rapidly. Thus, this method is usable for developing the new portable instrument to classify building materials, etc. (author)

  19. Radon emanometry in active volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, J.L.; Monnin, M. (CNRS, IN2P3, BP45/F63170 Aubiere (France)); Cejudo, J. (Instituto Nacional de Investigaciones Nucleares, Mexico City)

    1984-01-01

    Radon emission measurements from active volcanoes has, since 1981, been continuously measured at monitoring stations in Mexico and in Costa Rica. Counting of etched alpha tracks on cellulose nitrate LR-115 detectors give varying results at the several stations. Radon emanation at Chichon, where an explosive eruption occurred in 1982, fell down. Radon detection at the active volcano in Colima shows a pattern of very low emission. At the Costa Rica stations located at Poas, Arenal and Irazu, the radon emanation shows regularity.

  20. Radon risk in residential buildings

    International Nuclear Information System (INIS)

    Niewiadomski, T.

    1996-01-01

    The author discusses the risk related to the inhalation of radon decay products. This products are the cause of almost the half of the doses absorbed by the people. The concentration of radon in buildings is much higher than in the open areas and its country average in Poland is 50 Bq/m 3 . It is difficult to predict the concentration of radon in the building without measurement. Author concludes that there are technical means to decrease radon concentration in buildings

  1. An investigation of radon mitigation in Pennsylvania

    International Nuclear Information System (INIS)

    Belanger, W.E.

    1990-01-01

    This paper reports that Radon mitigation contractors were contacted to obtain information on the progress of radon mitigation in Pennsylvania. Information was obtained on the beginning and ending radon concentrations, the cost of the job, the mitigation method used, and the location by zip code. Most radon mitigations achieved reductions below 90 percent, and most achieved 4 pCi/1. 65 percent achieved 2 pCi/1. There was little relationship between the cost of the job and either the percent reduction or the beginning radon. Percent reduction was strongly related to beginning radon, with lower percent reductions associated with low starting radon

  2. Effect of natural ventilation on radon and radon progeny levels in houses. Rept. for Apr 90-Sep 91

    International Nuclear Information System (INIS)

    Cavallo, A.; Gadsby, K.; Reddy, T.A.; Socolow, R.

    1991-01-01

    The paper discusses the effect of natural ventilation on radon and radon progeny levels in houses. Contradicting the widely held assumption that ventilation is ineffective in reducing indoor radon concentrations, experiments in a research house have shown that the basement radon level can be reduced by a factor of 5 to 10 using only natural ventilation. Measurement of the outdoor-basement pressure differential and the radon entry rate shows that this unexpectedly large reduction in indoor radon levels is caused by two complementary physical processes: (1) the obvious one, dilution, which lowers radon concentrations by adding uncontaminated outdoor air; and (2) although less evident, introducing a pressure break in the system through an open basement window which, in turn, reduces the outdoor-basement pressure differential and the rate at which radon-laden soil gas is drawn into the house. The radon entry rate was found to be a linear function of basement depressurization up to a differential pressure of about 4 Pa, as would be expected for laminar soil gas flow; opening two basement windows approximately doubled the building air exchange rate and reduced the radon entry rate by up to a factor of 5

  3. Indoor radon survey in dwellings of nine cities in the eastern and western provinces of Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Jarad, F.; Fazal-ur-Rehman; Al-Jarallah, M.I.; Al-Shukri, A

    2003-07-01

    The results of a first phase of an indoor survey in a total of 1610 dwellings distributed in nine cities of the Eastern and the Western provinces of Saudi Arabia are presented. The objective of this radon survey was to obtain representative indoor radon data for seven cities in the Eastern province, Khafji, Hafr Al-Batin, Abqaiq, Qatif, Al-Ahsa, Dammam and Khobar and to compare this with two cities in the Western province, Madina and Taif. So far, detailed radon data is not available for Saudi Arabia; therefore, this radon survey provides a base line for Saudi Arabia in the Radon World Atlas. On average, 200 indoor radon dosemeters were distributed in each city and placed for a period of one year starting from May 2001 to May 2002. The total number of collected dosemeters was 847. A total of 724 houses and 98 schools were covered in this survey. The results of the survey in the cities showed that the overall minimum, maximum and average radon concentrations were 1, 137 and 22 Bq m {sup -3}, respectively. Geometric mean and geometric standard deviations of the radon distribution were found to be 18 and 1.92, respectively. In one of the dwellings in Qatif city, radon concentration, measured by a passive system and then confirmed by an active system, was found to be 535 {+-} 23 and 523 {+-} 22 Bq m {sup -3}, respectively. The result of a radon survey in 98 schools showed that the minimum, maximum and average radon concentrations were 1, 70 and 19 Bq m{sup -3}, respectively. The average radon concentration for each city was also determined. The lowest average radon concentration (8 Bq m{sup -3}) was found in Al-Ahsa while the highest average concentration (40 Bq m {sup -3}) was found in Khafji. (author)

  4. 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)

  5. 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.

  6. 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)

  7. Discussion on the source of radon in uranium exploration method using radon-released thermal effect in minerals

    International Nuclear Information System (INIS)

    Su Shoutian.

    1985-01-01

    This paper considers the problem of the source of radon in uranium exploration method using radon-released thermal effect. In minerals by means of scintillation emanometry, we have carried out the measurement on radon content in minerals at various temperature in barren and ore-bearing granites of the granite-type uranium deposit No. 752, and inclusion decrepitation method has also been used to determine the temperature of decrepitation and its relative frequency. It was found from experiments that heated samples may release most of radon prior to inclusion decrepitation, radon released from thermal effect was, on the contrary, very little at temperature intervals of inclusion decrepitation on a large scale basis. When inclusions were ground after radon releasing, it would still release from inclusions after reheating. The radon content calculated from uranium content in inclusions is lower than the sensitivity of the determination method, so it is too difficult to be determined, indicating that the radon content released is not related to inclusions. Samples were determined by uranium chemical analysis and radium radiochemical analysis and it is obvious to note that the radon content released from thermal effect in minerals is positively correlated to the uranium and radium content. Various kinds of experiments suggest that radon is not derived from inclusions but from the whole mineral

  8. Second workshop on radon and radon daughters in urban communities associated with uranium mining and processing

    International Nuclear Information System (INIS)

    1979-01-01

    A second meeting of Atomic Energy Control Board staff, federal and provincial government representatives, and consultants was held to discuss progress in reducing the concentrations of radon and its daughter products in houses in communities like Bancroft, Elliot Lake, Port Hope, and Uranium City. Participants discussed successful and unsuccessful remedial techniques, possible sources of radon, and methods of measuring radon and radon daughters in buildings

  9. Locating and limiting radon in dwellings

    International Nuclear Information System (INIS)

    Hildingson, O.; Gustafsson, J.; Nilsson, I.

    1984-01-01

    More than 3,300 Swedish dwellings have an indoor radon daughter concentration above 400 Bq.m -3 (or 0.108 WL). It is considered to be unsafe to live in any of these dwellings and the radon daughter concentration has to be reduced. Before deciding what measures to take, it is important to determine the radon sources. Possible sources are exhalation from building materials and/or radon transport from the ground into the building through cracks and joints in the slab. Different methods of locating the sources have been developed. To locate cracks and joints in slabs the ventilation rate and the air pressure difference relative to the ground are changed while monitoring radon/radon daughter concentration. The effect of five different measures to reduce the indoor radon daughter concentration have also been evaluated: increased ventilation rate by mechanical ventilation, ventilation of the small spaces between the floor and the slab, sealing the surface of radon exhaling walls, sealing joints and cracks in the slab, and ventilation of the drainage under the slab. (author)

  10. Legal issues in radon affairs

    International Nuclear Information System (INIS)

    Massuelle, M.H.

    1999-01-01

    In France, it was only recently that cases related to high radon concentrations in dwellings received substantial publicity. This irruption of radon as a public health issue came with the general progress of scientific knowledge and the availability of a research capacity in France able to develop expertise. We are interested here in the legal implications of issues that arise from the lag between the activity of experts and the regulatory activity in the domain of radon. We use the term expertise very broadly, to cover the practical application of research findings, the relation of the researchers with the community, and finally the acts by which experts provide their knowledge to the community. We first examine the course by which science developed the radon issue and the way they organized to move from research to expertise; here we try to characterize the various needs for radon expertise. We then discuss the legal difficulties associated with radon expertise

  11. Legal issues in radon affairs

    Energy Technology Data Exchange (ETDEWEB)

    Massuelle, M.H. [Inst. de Protection et de Surete Nucleaire, Fontenay aux Roses (France)

    1999-12-01

    In France, it was only recently that cases related to high radon concentrations in dwellings received substantial publicity. This irruption of radon as a public health issue came with the general progress of scientific knowledge and the availability of a research capacity in France able to develop expertise. We are interested here in the legal implications of issues that arise from the lag between the activity of expertsand the regulatory activity in the domain of radon. We use the term expertise very broadly, to cover the practical application of research findings, the relation of the researchers with the community, and finally the acts by which experts provide their knowledge to the community. We first examine the course by which science developed the radon issue and the way they organized to move from research to expertise; here we try to characterize the various needs for radon expertise. We then discuss the legal difficulties associated with radon expertise.

  12. Determination of air-loop volume and radon partition coefficient for measuring radon in water sample.

    Science.gov (United States)

    Lee, Kil Yong; Burnett, William C

    A simple method for the direct determination of the air-loop volume in a RAD7 system as well as the radon partition coefficient was developed allowing for an accurate measurement of the radon activity in any type of water. The air-loop volume may be measured directly using an external radon source and an empty bottle with a precisely measured volume. The partition coefficient and activity of radon in the water sample may then be determined via the RAD7 using the determined air-loop volume. Activity ratios instead of absolute activities were used to measure the air-loop volume and the radon partition coefficient. In order to verify this approach, we measured the radon partition coefficient in deionized water in the temperature range of 10-30 °C and compared the values to those calculated from the well-known Weigel equation. The results were within 5 % variance throughout the temperature range. We also applied the approach for measurement of the radon partition coefficient in synthetic saline water (0-75 ppt salinity) as well as tap water. The radon activity of the tap water sample was determined by this method as well as the standard RAD-H 2 O and BigBottle RAD-H 2 O. The results have shown good agreement between this method and the standard methods.

  13. Determination of air-loop volume and radon partition coefficient for measuring radon in water sample

    International Nuclear Information System (INIS)

    Kil Yong Lee; Burnett, W.C.

    2013-01-01

    A simple method for the direct determination of the air-loop volume in a RAD7 system as well as the radon partition coefficient was developed allowing for an accurate measurement of the radon activity in any type of water. The air-loop volume may be measured directly using an external radon source and an empty bottle with a precisely measured volume. The partition coefficient and activity of radon in the water sample may then be determined via the RAD7 using the determined air-loop volume. Activity ratios instead of absolute activities were used to measure the air-loop volume and the radon partition coefficient. In order to verify this approach, we measured the radon partition coefficient in deionized water in the temperature range of 10-30 deg C and compared the values to those calculated from the well-known Weigel equation. The results were within 5 % variance throughout the temperature range. We also applied the approach for measurement of the radon partition coefficient in synthetic saline water (0-75 ppt salinity) as well as tap water. The radon activity of the tap water sample was determined by this method as well as the standard RAD-H 2 O and BigBottle RAD-H 2 O. The results have shown good agreement between this method and the standard methods. (author)

  14. Radon anomalies prior to earthquakes (2). Atmospheric radon anomaly observed before the Hyogoken-Nanbu earthquake

    International Nuclear Information System (INIS)

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

    2008-01-01

    Before the 1995 Hyogoken-Nanbu earthquake, various geochemical precursors were observed in the aftershock area: chloride ion concentration, groundwater discharge rate, groundwater radon concentration and so on. Kobe Pharmaceutical University (KPU) is located about 25 km northeast from the epicenter and within the aftershock area. Atmospheric radon concentration had been continuously measured from 1984 at KPU, using a flow-type ionization chamber. The radon concentration data were analyzed using the smoothed residual values which represent the daily minimum of radon concentration with the exclusion of normalized seasonal variation. The radon concentration (smoothed residual values) demonstrated an upward trend about two months before the Hyogoken-Nanbu earthquake. The trend can be well fitted to a log-periodic model related to earthquake fault dynamics. As a result of model fitting, a critical point was calculated to be between 13 and 27 January 1995, which was in good agreement with the occurrence date of earthquake (17 January 1995). The mechanism of radon anomaly before earthquakes is not fully understood. However, it might be possible to detect atmospheric radon anomaly as a precursor before a large earthquake, if (1) the measurement is conducted near the earthquake fault, (2) the monitoring station is located on granite (radon-rich) areas, and (3) the measurement is conducted for more than several years before the earthquake to obtain background data. (author)

  15. Radon legislation and national guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Aakerblom, G

    1999-07-01

    The International Commission on Radiological Protection (ICRP) and The Council of the European Union have recommended the Member States to take action against radon in homes and at workplaces. Within the EU project European Research into Radon in Construction Concerted Action, ERRICCA, the Topic Group on Legal and Building Code Impact was designated to study the current radon legislation and give advice regarding future enactment of laws and recommendations. On behalf of the Group, a questionnaire on radon legislation was sent out to nearly all European states and a selection of non-European states. Questions were asked regarding reference levels for dwellings, workplaces and drinking water, and about regulations or recommendations for building materials and city planning. All 15 EU Member States, 17 non-EU European countries and 10 non-European countries responded to the questionnaire. Their answers are considered current as of the end of 1998. Most European States and many non-European countries have recommended reference levels for dwellings and workplaces, and some have guidelines for measures against radon incorporated in their building codes and guidelines for construction techniques. However, only a few countries have enforced reference levels or regulations for planning and construction. The reference levels for indoor radon concentration in existing and new dwellings or workplaces are within the range 150-1000 Bq/m{sup 3}. Sweden is the only country (Out of 15 EU member states) which has enforced limits for existing dwellings. Sweden and the UK have both enforced levels for new dwellings. 7 non-European countries (Out of 17 responding countries) have enforced levels for existing dwellings and 9 have them for new dwellings. At the end of 1998, only Finland, Sweden, the Czech Republic, Romania, Russia and the Slovak Republic had limits for radon in water, although 8 countries were planning to introduce such limits. The present limits are within the range for

  16. Radon legislation and national guidelines

    International Nuclear Information System (INIS)

    Aakerblom, G.

    1999-07-01

    The International Commission on Radiological Protection (ICRP) and The Council of the European Union have recommended the Member States to take action against radon in homes and at workplaces. Within the EU project European Research into Radon in Construction Concerted Action, ERRICCA, the Topic Group on Legal and Building Code Impact was designated to study the current radon legislation and give advice regarding future enactment of laws and recommendations. On behalf of the Group, a questionnaire on radon legislation was sent out to nearly all European states and a selection of non-European states. Questions were asked regarding reference levels for dwellings, workplaces and drinking water, and about regulations or recommendations for building materials and city planning. All 15 EU Member States, 17 non-EU European countries and 10 non-European countries responded to the questionnaire. Their answers are considered current as of the end of 1998. Most European States and many non-European countries have recommended reference levels for dwellings and workplaces, and some have guidelines for measures against radon incorporated in their building codes and guidelines for construction techniques. However, only a few countries have enforced reference levels or regulations for planning and construction. The reference levels for indoor radon concentration in existing and new dwellings or workplaces are within the range 150-1000 Bq/m 3 . Sweden is the only country (Out of 15 EU member states) which has enforced limits for existing dwellings. Sweden and the UK have both enforced levels for new dwellings. 7 non-European countries (Out of 17 responding countries) have enforced levels for existing dwellings and 9 have them for new dwellings. At the end of 1998, only Finland, Sweden, the Czech Republic, Romania, Russia and the Slovak Republic had limits for radon in water, although 8 countries were planning to introduce such limits. The present limits are within the range for 50

  17. A novel structure of transmission line pulse transformer with mutually coupled windings.

    Science.gov (United States)

    Yu, Binxiong; Su, Jiancang; Li, Rui; Zhao, Liang; Zhang, Xibo; Wang, Junjie

    2014-03-01

    A novel structure of transmission line transformer (TLT) with mutually coupled windings is described in this paper. All transmission lines except the first stage of the transformer are wound on a common ferrite core for the TLT with this structure. A referral method was introduced to analyze the TLT with this structure, and an analytic expression of the step response was derived. It is shown that a TLT with this structure has a significantly slower droop rate than a TLT with other winding structures and the number of ferrite cores needed is largely reduced. A four-stage TLT with this structure was developed, whose input and output impedance were 4.2 Ω and 67.7 Ω, respectively. A frequency response test of the TLT was carried out. The test results showed that pulse response time of the TLT is several nanoseconds. The TLT described in this paper has the potential to be used as a rectangle pulse transformer with very fast response time.

  18. Radon in Dwellings in the Republic of Kalmykia. Results from the National Radon Survey 2006-2007

    International Nuclear Information System (INIS)

    Aakerblom, Gustav; German, Olga; Soederman, Ann-Louise; Stamat, Ivan; Venkov, Vladimir

    2009-02-01

    The National Radon Survey in the Republic of Kalmykia, Russian Federation during 2006-2007 was carried out in a cooperation project between the Swedish Radiation Protection Authority (SSI) and the Russian Institute of Radiation Hygiene (RIRH). In August 2006 SSI, RIRH, federal and local authorities carried out a field study in Kalmykia when radon daughter measurements (equilibrium equivalent radon concentrations in the air) and gamma radiation measurements were made in 103 buildings. Gamma spectrometry measurements were made at several sites. During the visit the cooperating parties devoted some time to the education of local authorities on radon related issues. During three months in the winter season 2006-2007, long term radon trace measurements were made in 525 randomly chosen dwellings in the Republic of Kalmykia. The radon gas activity varied between 3 and 973 Bq/m 3 , with a mean value of 122 Bq/m 3 . In 19 of a total of 835 measurement points, the radon activity exceeded the maximum permitted value in Russia of 200 Bq/m 3 of EERC. The year-round radon trace measurement were made in 20 houses in Elista, the capital of the Republic of Kalmykia, for comparison with the three-month measurements. The year-round measurements showed some higher values for the radon activity, and a correction factor of 0.85 was applied. Using data on the number of people living in detached houses and apartments, and applying the radon activities measured, the number of new lung cancer cases caused by radon was calculated to be 20 to 40 of the 100 new cases reported annually. The methods of construction of the dwellings in Kalmykia is greatly influenced by the history and culture. Most of them were built after World War II and there are only a few that are newly built because of the poor economic situation and the low population growth rate in the Republic. Most people live in detached houses, one-storied with 3-5 rooms, built directly on the ground or on coquina blocks or on a cast

  19. Remedial measures in Swedish and Norwegian houses - application of radon and radon decay product measurements

    International Nuclear Information System (INIS)

    Just, G.; Philipsborn, H. von; Matolin, M.; Molzahn, D.

    1998-01-01

    Houses and apartments in Sweden and Norway with excessive indoor radon concentrations were studied in detail with a variety of methods, standard and novel ones recently developed. For suitable remediation it is necessary to distinguish soil radon and exhalation from blue (porous) concrete. Our CARBOTEST-S is a simple, sensitive, in-situ method to quantify radon exhalation from existing walls, as well as radon permeability of different protective foils and final quality control of foils applied to existing walls. (orig.) [de

  20. Radon levels in Oslo schools

    International Nuclear Information System (INIS)

    Birovlev, A.

    2004-01-01

    Radon measurements using passive CR-39 detectors have been conducted in all schools in Oslo municipality during winter 2003/2004. Results are presented and discussed in the light of qualitative and quantitative factors, some of which are specific for schools as workplaces. Analysis is conducted with respect to factors relating to building construction type, ventilation principle, age of building, building size etc. The influence of ventilation type on radon levels is studied, and problems of investigations based purely on conventional passive radon detectors are noted. Over-estimation of radon concentration by passive detectors and day-night variations of indoor radon levels in buildings with mechanical ventilation systems are discussed. Several guiding principles for planning similar investigations based on above discussions are outlined. (author)

  1. Radon measurements in hispaniola dwellings

    International Nuclear Information System (INIS)

    Gutierrez, J.; Colgan, P.A.; Cancio, D.

    1996-01-01

    The results of a national radon survey and a number of regional surveys of radon in spanish dwelling are reviewed. The best estimate of the geometric mean of indoor radon concentrations is 41.1. Bq/m -3 and single-family dwellings have been shown to be more at risk than apartments. Results need to be interpreted with some caution due to differences in survey methodologies and measurement procedures. The risks from radon exposure are put in perspective by comparison with other voluntary risks. Finally, although a number of 'high risk' areas have already been identified, it is concluded that implementation of a national programme to reduce radon exposure may await a better definition of the problem extent. (authors). 20 refs., 1 tab

  2. Ion climate and radon concentration

    International Nuclear Information System (INIS)

    Busbarna, L.

    1981-01-01

    Characteristic values of radon concentration in natural ion climate and in open air were compared and the effect of artificially produced negative ion excess on the radon concentration of air was studied. The results show that the radon concentration measurable at the rise of negative ion excess is smaller than that in the case of natural equilibrium. This effect can be utilized lowering the background of the scintillation chambers, thus increasing their sensitivity. The negative ions of the artificial ion climate lower radon concentration in closed space. The question arises whether only the ion climate is responsible for the effects on the organism and on the nervous system or the radon concentration of the air also contributes to them. (author)

  3. 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)

  4. Radon mapping - Santa Barbara and Ventura counties

    International Nuclear Information System (INIS)

    Churchill, R.

    1997-01-01

    Since 1990, the Department of Conservation''s Division of Mines and Geology (DMG) has provided geologic information and conducted several research projects on geology and radon for the California Department of Health Services (DHS) Radon Program. This article provides a brief overview of radon''s occurrence and impact on human health, and summarizes a recent DMG project for DHS that used geologic, geochemical, and indoor radon measurement data to produce detailed radon potential zone maps for Santa Barbara and Ventura counties

  5. 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

  6. Communicating radon risk effectively: Radon testing in Maryland. Final report

    International Nuclear Information System (INIS)

    Desvousges, W.H.; Smith, V.K.; Rink, H.H.

    1988-10-01

    Two sets of materials and corresponding delivery strategies for communicating radon risk were evaluated, compared with a 'no-special-treatment' strategy in a comparison community. One community received radio public-service announcements and utility bill inserts. The second received these plus posters, local government sponsorship of a radon awareness week, and local slide presentations. The most-intensive efforts (multiple channels, multiple hits) were more effective than the less intensive effort, which had little impact compared with no special treatment. From a marketing perspective, the effort was very successful, increasing the share of homeowners who tested for radon from 5% to 15%. This may not be viewed as sufficiently effective from a public-health perspective, however

  7. Characterising fifteen years of continuous atmospheric radon activity observations at Cape Point (South Africa)

    Science.gov (United States)

    Botha, R.; Labuschagne, C.; Williams, A. G.; Bosman, G.; Brunke, E.-G.; Rossouw, A.; Lindsay, R.

    2018-03-01

    This paper describes and discusses fifteen years (1999-2013) of continuous hourly atmospheric radon (222Rn) monitoring at the coastal low-altitude Southern Hemisphere Cape Point Station in South Africa. A strong seasonal cycle is evident in the observed radon concentrations, with maxima during the winter months, when air masses arriving at the Cape Point station from over the African continental surface are more frequently observed, and minima during the summer months, when an oceanic fetch is predominant. An atmospheric mean radon activity concentration of 676 ± 2 mBq/m3 is found over the 15-year record, having a strongly skewed distribution that exhibits a large number of events falling into a compact range of low values (corresponding to oceanic air masses), and a smaller number of events with high radon values spread over a wide range (corresponding to continental air masses). The mean radon concentration from continental air masses (1 004 ± 6 mBq/m3) is about two times higher compared to oceanic air masses (479 ± 3 mBq/m3). The number of atmospheric radon events observed is strongly dependent on the wind direction. A power spectral Fast Fourier Transform analysis of the 15-year radon time series reveals prominent peaks at semi-diurnal, diurnal and annual timescales. Two inter-annual radon periodicities have been established, the diurnal 0.98 ± 0.04 day-1 and half-diurnal 2.07 ± 0.15 day-1. The annual peak reflects major seasonal changes in the patterns of offshore versus onshore flow associated with regional/hemispheric circulation patterns, whereas the diurnal and semi-diurnal peaks together reflect the influence of local nocturnal radon build-up over land, and the interplay between mesoscale sea/land breezes. The winter-time diurnal radon concentration had a significant decrease of about 200 mBq/m3 (17%) while the summer-time diurnal radon concentration revealed nearly no changes. A slow decline in the higher radon percentiles (75th and 95th) for the

  8. Radon as a remedy - radiobiological and medical aspects, risk; Radon als Heilmittel - strahlenbiologische und medizinische Aspekte, Risiko

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, E.R.; Nuernberger, E.; Martignoni, K. [Inst. fuer Strahlenhygiene des Bundesamtes fuer Strahlenschutz, Oberschleissheim/Neuherberg (Germany)

    1995-09-01

    For years there have been controversial discussions about the benefit and risk of radon-balneo-therapy. This is particularly true where the inhalation of radon and its daughter products in curative galleries is concerned. Animal experiments and studies on uranium miners have clearly shown that the exposure with radon and its daughter products is connected with an additional risk for lung cancer. Findings on balneo-therapeutic mechanisms are, at best, incomplete and the topic of controversial discussions in radiobiology. This applies specifically to `hormesis` or `adaptive response`, as indicated in this context. Given the numerous reports of therapeutic results, there appear to be curative effects from radon-balneotherapy for special indications. (orig.) [Deutsch] Nutzen und Risiko der Radon-Balneotherapie werden seit Jahren widerspruechlich diskutiert. Dies gilt insbesondere fuer die Inhalation des Radons und seiner Folgeprodukte in Heilstollen. Tierversuche und Untersuchungen bei Uranbergleuten haben eindeutig gezeigt, dass mit der Exposition durch Radon und seinen Folgeprodukten ein zusaetzliches Lungenkrebsrisiko verbunden ist. Erkenntnisse zum Wirkungsmechanismus der Radon-Balneotherapie liegen allenfalls in Ansaetzen vor und werden in der Strahlenbiologie kontrovers diskutiert. Dies gilt insbesondere fuer die in diesem Zusammenhang angefuehrte `Hormesis` bzw. `Adaptive Response`. Geht man von den zahlreich berichteten therapeutischen Erfahrungen aus, so scheint es Hinweise auf Heileffekte der Radon-Balneotherapie fuer spezielle Indikationen zu geben. (orig.)

  9. Tesla-transformer-type electron beam accelerator

    International Nuclear Information System (INIS)

    Liu Jinliang; Zhong Huihuang; Tan Qimei; Li Chuanlu; Zhang Jiande

    2002-01-01

    An electron-beam Tesla-transformer accelerator is described. It consists of the primary storage energy system. Tesla transformer, oil Blumlein pulse form line, and the vacuum diode. The experiments of initial stage showed that diode voltage rises up to about 500 kV with an input of 20 kV and the maximum electron-beam current is about 9 kA, the pulse width is about 50 ns. This device can operate stably and be set up easily

  10. Experience with on-line diagnostics for bushings and current transformers

    Energy Technology Data Exchange (ETDEWEB)

    Brusetti, R.

    2004-02-01

    The application of on-line diagnostic techniques is advocated as an alternative, under certain conditions, for the conventional off-line power factor test used to evaluate the condition of bushings and current transformers. Bushings which are tied to critical system apparatus or which cannot be readily removed from service are considered to be excellent candidates for on-line diagnostics. A case history involving 138-KV bushings is used to demonstrate the value of the on-line diagnostic system which, by taking into account power factor capacitance values along with the rate of change, not only detected the high power factor associated with the bushings, but allowed the high power factor bushings to continue operating with a known problem for over a year. With conventional testing, bushings that exhibited this level of power factor would typically be removed from service. 4 refs., 3 figs.

  11. Numerical and analytical assessment of radon diffusion in various media and potential of charcoal as radon detector

    Science.gov (United States)

    Rybalkin, Andrey

    Numerical assessments of radon diffusion together with analytical estimates for short-time and long-time exposure were the first objective of this thesis with the goal to demonstrate how radon propagates in various media. Theoretical predictions were compared to numerical simulations, and obtained values of total radon activities inside each material match quite well with the analytical estimates. These estimates, for activated and nonactivated charcoal, were then used to evaluate the possibility of designing a charcoal system to be used as a radon detector. Another objective was to use nonactivated charcoal samples and measure the level of radon accumulation, and use these data to estimate radon diffusion and adsorption coefficients. The analytical approach was developed to estimate these values. Radon adsorption coefficient in nonactivated charcoal was found to be from 0.2 to 0.4 m3/kg. Radon diffusion coefficient for nonactivated charcoal is in the range of 1.2×10-11 to 5.1×10-10 m2/s in comparison to activated charcoal with adsorption coefficient of 4 m3/kg and diffusion coefficient of 1.43×10-9 m2/s. The third objective was to use GEANT4 numerical code to simulate decay of 238U series and 222Rn in an arbitrary soil sample. Based on that model, the goal was to provide a guideline for merging GEANT4 radioactive decay modeling with the diffusion of radon in a soil sample. It is known that radon can be used as an earthquake predictor by measuring its concentration in groundwater, or if possible, along the faults. Numerical simulations of radon migration by diffusion only were made to estimate how fast and how far radon can move along the fault strands. Among the known cases of successful correlations between radon concentration anomalies and earthquake are the 1966 Tashkent and 1976 Songpan-Pingwu earthquakes. Thus, an idea of radon monitoring along the Wasatch Fault, using system of activated/nonactivated charcoals together with solid state radon detectors is

  12. Radon and its daughters in vivo

    International Nuclear Information System (INIS)

    Rundo, J.

    1983-01-01

    Some aspects of the behavior of radon and its short-lived daughters in vivo are described and a relationship between the radon exhalation rate and time after a meal is demonstrated. A major but short-lived postprandial increase in the exhalation rate of radon produced from skeletally-deposited radium was observed and a similar effect in exhalation rate of environmental radon by persons containing no radium was noted. Persons living in houses with elevated concentrations of radon may contain sufficient activity for its detection by external gamma-ray counting. Some of the activity observed is due to inhaled daughter-products in the chest, and some to daughter-products associated with and produced by the decay of radon throughout the body. 3 references, 8 figures. (MF)

  13. 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....

  14. Standardised Radon Index (SRI: a normalisation of radon data-sets in terms of standard normal variables

    Directory of Open Access Journals (Sweden)

    R. G. M. Crockett

    2011-07-01

    Full Text Available During the second half of 2002, from late June to mid December, the University of Northampton Radon Research Group operated two continuous hourly-sampling radon detectors 2.25 km apart in the English East Midlands. This period included the Dudley earthquake (ML = 5, 22 September 2002 and also a smaller earthquake in the English Channel (ML = 3, 26 August 2002. Rolling/sliding windowed cross-correlation of the paired radon time-series revealed periods of simultaneous similar radon anomalies which occurred at the time of these earthquakes but at no other times during the overall radon monitoring period. Standardising the radon data in terms of probability of magnitude, analogous to the Standardised Precipitation Indices (SPIs used in drought modelling, which effectively equalises different non-linear responses, reveals that the dissimilar relative magnitudes of the anomalies are in fact closely equiprobabilistic. Such methods could help in identifying anomalous signals in radon – and other – time-series and in evaluating their statistical significance in terms of earthquake precursory behaviour.

  15. Internal services simulation control in 220/110kV power transformer station Mintia

    Science.gov (United States)

    Ciulica, D.; Rob, R.

    2018-01-01

    The main objectives in developing the electric transport and distribution networks infrastructure are satisfying the electric energy demand, ensuring the continuity of supply to customers, minimizing electricity losses in the transmission and distribution networks of public interest. This paper presents simulations in functioning of the internal services system 400/230 V ac in the 220/110 kV power transformer station Mintia. Using simulations in Visual Basic, the following premises are taken into consideration. All the ac consumers of the 220/110 kV power transformer station Mintia will be supplied by three 400/230 V transformers for internal services which can mutual reserve. In case of damaging at one transformer, the others are able to assume the entire consumption using automatic release of reserves. The simulation program studies three variants in which the continuity of supply to customers are ensured. As well, by simulations, all the functioning situations are analyzed in detail.

  16. Radon problem in uranium industry

    International Nuclear Information System (INIS)

    Khan, A.H.; Raghavayya, M.

    1991-01-01

    Radon emission is invariably associated with the mining and processing of uranium ores. Radon (sup(222)Rn) enters mine atmosphere through diffusion from exposed ore body, fractures and fissures in the rocks and is also brought in by ground water. Being the progenitor of a series of short lived radioisotopes it contributes over 70% of the radiation dose to mine workers and thus accounts for nearly 30% of the total radiation doses received by workers in the whole nuclear industry. This paper summarises the data on radon emanation from the ore body, backfilled sands and mine water. Radon and its progeny concentrations in different haulage levels and stopes of the Jaduguda uranium mine are presented to emphasise the need for a well planned ventilation system to control radiation exposure of miners. Results of radon monitoring from a few exploratory uranium mines are included to indicate the need for a good ventilation system from inception of the mining operations. Relative contribution of mine exhaust and tailings surfaces to the environmental radon are also given. Some instruments developed locally for monitoring of radon and its progeny in mines and in the environment are briefly described to indicate the progress made in this field. (author). 17 refs., 2 figs., 6 tabs

  17. Radon and energy efficient homes

    International Nuclear Information System (INIS)

    Burkart, W.

    1981-09-01

    Radon and its daughters in indoor air are presently responsible for dose equivalents of about 31 mSv/year (3 rem/year) to parts of the respiratory tract. Linear extrapolation from the dose response values of uranium miners heavily exposed to radon and its decay products would suggest that almost all lung cancers in the non-smoking population are caused by environmental 222 Rn. Using epidemiological data on the types of lung cancer found in non-smokers of the general public as compared to the miners, a smaller effect of low level radon exposure is assumed, which would result in a lung cancer mortality rate due to radon of about 10 deaths per year and million or 25% of the non-smoker rate. Higher indoor radon concentrations in energy efficient homes mostly caused by reduced air exchange rates will lead to a several fold increase of the lung cancer incidence from radon. Based on the above assumption, about 100 additional lung cancer deaths/year-million will result both from an increase in radionuclide concentrations in indoor air and a concomitant rise in effectiveness of radiation to cause cancer with higher exposure levels. Possibilities to reduce indoor radon levels in existing buildings and costs involved are discussed. (Auth.)

  18. Radon monitoring technique with electret collecting

    International Nuclear Information System (INIS)

    Tian Zhiheng; Zuo Fuqi; Xiao Detao; Zhao Xkiuliang

    1991-12-01

    The integrating radon monitoring technique with electret collecting is a method which collects the 218 Po + positive ions by electrostatic field produced by electret. It has greatly improved the sensitivity of radon measurement. The response factor of this method reaches to 4.7 cm -2 Bq -1 m 3 h -1 , 1000 times larger than that of common passive sampling method. The monitoring device and its principle are introduced. The measuring results of radon concentration and radon flux rate and quality assurance system by using this method in the Qinshan Nuclear Power Plant, Human Environmental Monitoring Central Station and some uranium mines are also presented. The analytical results show that the radon concentration in the Qinshan Nuclear Power Plant is affected by wind direction. When wind directs toward sea, the radon concentration is high. If the wind is to the contrary, it is low. The radon concentration ratio of both is about 2

  19. Characterizing the source of radon indoors

    International Nuclear Information System (INIS)

    Nero, A.V.; Nazaroff, W.W.

    1983-09-01

    Average indoor radon concentrations range over more than two orders of magnitude, largely because of variability in the rate at which radon enters from building materials, soil, and water supplies. Determining the indoor source magnitude requires knowledge of the generation of radon in source materials, its movement within materials by diffusion and convection, and the means of its entry into buildings. This paper reviews the state of understanding of indoor radon sources and transport. Our understanding of generation rates in and movement through building materials is relatively complete and indicates that, except for materials with unusually high radionuclide contents, these sources can account for observed indoor radon concentrations only at the low end of the range observed. Our understanding of how radon enters buildings from surrounding soil is poorer, however recent experimental and theoretical studies suggest that soil may be the predominant source in many cases where the indoor radon concentration is high. 73 references, 3 figures, 1 table

  20. Comparative study of radon in Sudan

    International Nuclear Information System (INIS)

    Gharbi, Shaza Ismail Mohammed

    2014-07-01

    This study was conducted primarily to contribute radon data for radon map in Sudan and identify regions with elevated radon levels and improve data collection and analysis for the future radon levels evaluation. This study partially covered three states of Sudan ( Red Sea - Khartoum - South Khordofan). Previous work done has been considered in this study which focused and investigated the levels of radon concentration in ( indoor radon gas and water) by using gamma spectrometry equipped with ( HPGe detector) or (Na1 (T1) detector). The results obtained are within the acceptable levels and dose not poses any risk from radiation protection point of view. Red Sea state ( port-sudan): (124.39±6.21) Bq/m 3 . Khartoum state ( Suba): (151.52) Bq/m 3 . (Omdurman): ( 127±23) Bq/m 3 . Radon in water: (59) Bq/L. South Kordofan State: (102.8) Bq/m 3 . In water (Kadugli): (3 1 39)) Bq/L.(Author)

  1. Research on the Error Characteristics of a 110 kV Optical Voltage Transformer under Three Conditions: In the Laboratory, Off-Line in the Field and During On-Line Operation

    Science.gov (United States)

    Xiao, Xia; Hu, Haoliang; Xu, Yan; Lei, Min; Xiong, Qianzhu

    2016-01-01

    Optical voltage transformers (OVTs) have been applied in power systems. When performing accuracy performance tests of OVTs large differences exist between the electromagnetic environment and the temperature variation in the laboratory and on-site. Therefore, OVTs may display different error characteristics under different conditions. In this paper, OVT prototypes with typical structures were selected to be tested for the error characteristics with the same testing equipment and testing method. The basic accuracy, the additional error caused by temperature and the adjacent phase in the laboratory, the accuracy in the field off-line, and the real-time monitoring error during on-line operation were tested. The error characteristics under the three conditions—laboratory, in the field off-line and during on-site operation—were compared and analyzed. The results showed that the effect of the transportation process, electromagnetic environment and the adjacent phase on the accuracy of OVTs could be ignored for level 0.2, but the error characteristics of OVTs are dependent on the environmental temperature and are sensitive to the temperature gradient. The temperature characteristics during on-line operation were significantly superior to those observed in the laboratory. PMID:27537895

  2. Utilisation of an Air-conditioning System to Control the Levels of Radon and Radon Progeny in a Workplace Environment

    International Nuclear Information System (INIS)

    Marley, F.

    2000-01-01

    From long-term real-time radon and radon progeny measurements taken in a relatively large retail store, cyclical patterns were evident, which were found to relate to the overriding influence of the timed air-conditioning system. Concentration of radon, radon progeny and the variability of F factor were found to depend significantly on the intermittent operation of this ventilation-air-conditioning system. After pressure equalisation remedial measures proved ineffective, the air-movement system was utilised to reduce the levels of radon and radon progeny to well within established norms applicable during working hours. It is demonstrated that the average levels for radon and radon progeny are reduced in absolute terms. This amounted to less than 12% of the general level, during designated work periods. Where air movement systems are already installed, as well as other circumstances, their regulation provides an economical solution to meeting legal and other standards for radon in the workplace. (author)

  3. A novel joint timing/frequency synchronization scheme based on Radon-Wigner transform of LFM signals in CO-OFDM systems

    Science.gov (United States)

    Liu, Jianfei; Wei, Ying; Zeng, Xiangye; Lu, Jia; Zhang, Shuangxi; Wang, Mengjun

    2018-03-01

    A joint timing and frequency synchronization method has been proposed for coherent optical orthogonal frequency-division multiplexing (CO-OFDM) system in this paper. The timing offset (TO), integer frequency offset (FO) and the fractional FO can be realized by only one training symbol, which consists of two linear frequency modulation (LFM) signals with opposite chirp rates. By detecting the peak of LFM signals after Radon-Wigner transform (RWT), the TO and the integer FO can be estimated at the same time, moreover, the fractional FO can be acquired correspondingly through the self-correlation characteristic of the same training symbol. Simulation results show that the proposed method can give a more accurate TO estimation than the existing methods, especially at poor OSNR conditions; for the FO estimation, both the fractional and the integer FO can be estimated through the proposed training symbol with no extra overhead, a more accurate estimation and a large FO estimation range of [ - 5 GHz, 5GHz] can be acquired.

  4. Riddle of radon

    International Nuclear Information System (INIS)

    O'Riordan, M.

    1996-01-01

    Why is the most significant source of human exposure to ionising radiation - and one that is so easy to reduce - not accorded the attention it deserves from those engaged in radiological protection nor the action it requires from those affected by it at work or at home? There are, after all, clear indications that high levels of radon exist and firm strands of evidence that radon causes cancer. Some national and international authorities have even developed regulations and recommendations to limit exposures. But radon still lies in the penumbra of protection because proponents of intervention lack conviction and opponents are full of passionate intensity. Little wonder that citizens are confused! (Author)

  5. Tracing and dealing with dwellings with high radon and radon daughter concentrations

    International Nuclear Information System (INIS)

    Ehdwall, Hans

    1980-01-01

    In the late 1970s it was found that a number of buildings in Sweden, primarily those made from alum shale-based concretes, had elevated radon and radon daughter levels. A special commission investigated the problem and established provisional limiting values for radon daughter exposures, gamma radiation from the ground, and the concentrations of radioactive materials in building materials. With regard to gamma radiation from the ground the commission proposed that no building be built in an area where outside gamma radiation exceeds 100 μR/h. For building materials a gamma index (mγ) and a radium index (mRa) are suggested: mγ = Csub(K)/10000 + Csub(Ra)/1000 + Csub(Th)/700; mRa = Csub(Ra)/200 (Csub(K), Csub(Ra) and Csub(Th) are the concentrations of potassium, radium and thorium respectively). The proposed limiting values are such that the gamma index and the radium index be less than 1. It is also suggested that action should be taken to reduce radon levels in buildings with radon daughter concentrations of 0.27 WL within two years and 0.10 WL within 5 years

  6. Environmental radon and cancer risk

    Energy Technology Data Exchange (ETDEWEB)

    Haque, A K.M.M.; Kirk, A E [South Bank Polytechnic, London (United Kingdom)

    1992-01-01

    Data collected from the office of Population Censuses and Surveys (OPCS) statistics and those published by the Leukaemia Research Fund (LRF) have been analysed with a view to examining whether radon is a possible causative agent in the induction of leukaemias. Radon concentration values have been taken from a NRPB survey. Positive correlation has been observed between radon concentration and incidence of acute myeloid leukaemia (AML), chronic myeloid leukaemia (CML), acute lymphoblastic leukaemia (ALL) and chronic lymphoid leukaemia (CLL). Employing the method of BEIR IV, the lifetime probability of leukaemia incidence, R[sub o], of a non-exposed person (zero radon concentration) has been calculated for AML, CML, ALL and CLL, which agree well with those values obtained from extrapolation of linear graphs of leukaemia deaths versus radon concentration. (author).

  7. Radon Infiltration in Rented Accommodation

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2017-01-01

    in homes was measured and the Buildings were registered for a series of variables describing upgrades, facilities, building components, Construction characteristics and used materials. In addition, the radon level was measured in the basement in 9 of the buildings. The mean year value of the indoor radon......Indoor radon levels were measured in 221 homes located in 53 buildings, including 28 multi-occupant houses and 25 single-family terraced houses. The homes consisted of rented accommodation located in buildings recorded as being constructed before 2010 and after the year 1850. The radon level...... radon levels exceeding 100 Bq/m3 in homes in multi-occupant houses was found to be very low, but the risk was highest on the ground floor in a building constructed with slab on ground....

  8. Radon availability in New Mexico

    International Nuclear Information System (INIS)

    McLemore, V.T.

    1995-01-01

    The New Mexico Bureau of Mines and Mineral Resources (NMBMMR) in cooperation with the Radiation Licensing and Registration Section of the New Mexico Environment Department (NMED) and the US Environmental Protection Agency (EPA) have been evaluating geologic and soil conditions that may contribute to elevated levels of indoor radon throughout New Mexico. Various data have been integrated and interpreted in order to determine areas of high radon availability. The purpose of this paper is to summarize some of these data for New Mexico and to discuss geologic controls on the distribution of radon. Areas in New Mexico have been identified from these data as having a high radon availability. It is not the intent of this report to alarm the public, but to provide data on the distribution of radon throughout New Mexico

  9. 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)

  10. Ventilation influence upon indoor air radon level

    International Nuclear Information System (INIS)

    Tian Deyuan

    1995-01-01

    Levels of indoor radon in air are studied by a continuous electrostatic radon monitor under normal living conditions to evaluate the influence of air conditioned ventilation on indoor air radon level. Results show that the indoor air radon concentrations are not much more than those without household conditioner living condition, although using household conditioner requires a sealed room which should lead to a higher radon level. Turning on air conditioner helps lower indoor radon level. Therefore, the total indoor air Rn levels are normal > ventilation > exhaust or in-draft > exhaust plus in-draft

  11. Determination of equilibrium factor between radon and its progeny using surface barrier detector for various shapes of passive radon dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Jamil, K. [PINSTECH, Islamabad (Pakistan). Environ. Radiat. Group; Fazal-ur-Rehman [PINSTECH, Islamabad (Pakistan). Environ. Radiat. Group; Ali, S. [PINSTECH, Islamabad (Pakistan). Environ. Radiat. Group; Khan, H.A. [PINSTECH, Islamabad (Pakistan). Environ. Radiat. Group

    1997-03-21

    In the field of radon dosimetry, it is customary to measure radon ({sup 222}Rn) concentration while potential health hazard is due to the radon short-lived progeny. When radon is in secular equilibrium, the measured activity of radon equals the activity of radon`s progeny. However, in practical cases an inequilibrium between radon and its progeny exists which is measured in terms of the equilibrium factor. To determine the equilibrium factor between radon and its progeny in a closed environment various shapes of passive dosimeters based upon solid state nuclear track detectors (SSNTDs) are employed. In order to observe the dependence of equilibrium factor upon shapes or effective volumes, experiments have been performed replacing the SSNTDs with a surface barrier detector in Karlsruhe diffusion chamber, pen-type and box-type dosimeters. Using the collected alpha spectra, the equilibrium factor has been determined for a radon-air mixture in a custom designed radon chamber simulating a closed environment of a room. The results show that the radon equilibrium factor is about 0.20 for different shapes of dosimeters studied in this research. It is concluded that the determination of equilibrium factor between radon and its progeny does not depend upon effective volume or shape of the passive dosimeters using alpha spectroscopic data acquired by surface barrier detector. (orig.).

  12. 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

  13. Verification of the differential biological effectiveness of photons in the energy range of 10 keV - 6 MeV based on oncogenic transformation rates in mouse embryofibroblasts and in the human CGL 1-hybrid cell line

    International Nuclear Information System (INIS)

    Schmid, E.

    2005-01-01

    Working on observations of neoplastic transformation in human hybrid CGL1 cells, Frankenberg et al. (Radiat.Res. 157, 99-105, 2002) recently reported a relative biological effectiveness (RBE M ) of 4.3 for mammography X-rays (29 kV) relative to 200 kV X-rays. With reference to data in the literature, they inferred a factor of about 8 relative to 60 Co y-rays and concluded that this result is relevant to risk estimation. However, these conclusions do not appear to be valid. The data from the transformation study exhibit uncertainties in the statistical analysis that preclude any generalisation of the inferred RBE M . The data selected or inferred from the literature are likewise insufficient to support the stated RBEs. We therefore designed a study to repeat, under well-defined irradiation and culture conditions, this earlier investigation and to assess the validity of the high RBE values of 29 kV X-rays that had ben reported. Neoplastic transformation of human CGL1 cell hybrids was examined after exposure to 29 kV X-rays (mammography X-rays) and conventional 220 kV X-rays. The experiments with the two types of X-rays were performed simultaneously and shared the same controls.The transformation yields with both radiation qualities were fitted to the linear-quadratic dependence on absorbed dose, and a corresponding analysis was performed for the data earlier obtained by Frankenberg et al. The transformation yields in the present study exceed those in the earlier investigations substantially and it appears that the difference reflects inadequate feeding conditions of the cell cultures in the early experiments. The standard error bands are derived and are seen to be considerably more narrow than in the present results

  14. Application of the inter-line PCR for the analyse of genomic rearrangements in radiation-transformed mammalian cell lines; Anwendung der Inter-Line PCR zur Analyse von genomischen Veraenderungen in strahlentransformierten Saeugerzellinien

    Energy Technology Data Exchange (ETDEWEB)

    Leibhard, S.; Smida, J. [Muenchen Univ. (Germany). Strahlenbiologisches Inst.; Eckardt-Schupp, F.; Hieber, L. [GSF-Inst. fuer Strahlenbiologie, Oberschleissheim (Germany)

    1996-12-31

    Repetitive DNA sequences of the LINE-family (long interspersed elements) that are widely distributed among the mammalian genome can be activated or altered by the exposure to ionizing radiation [1]. By the integration at new sites in the genome alterations in the expression of genes that are involved in cell transformation and/or carcinogenesis may occur [2, 3]. A new technique - the inter-LINE PCR - has been developed in order to detect and analyse such genomic rearrangements in radiation-transformed cell lines. From the sites of transformation- or tumour-specific changes in the genome it might be possible to develop new tumour markers for diagnostic purpose. (orig.) [Deutsch] Repetitive DNA-Sequenzen der LINE-Familie, die weit verbreitet im Genom von Saeugerzellen vorkommen, koennen durch Exposition mit ionisierender Strahlung aktiviert und veraendert werden [1]. Durch eine Neu- bzw. Reintegration an anderen Positionen im Genom kann es zu bedeutenden Veraenderungen im Genom der Zelle kommen. Die Expression von Genen, die bei den Prozessen der Zelltransformation bzw. der Karzinogenese beteiligt sind, kann dadurch veraendert werden [2, 3]. Mithilfe der von uns entwickelten Inter-LINE PCR und der anschliessenden Analyse der veraenderten Produktmuster nach gelelektrophoretischer Auftrennung koennen solche `genomic rearrangements` unter Beteiligung von LINE-Elementen untersucht und naeher charakterisiert werden. Durch Klonierung und Sequenzierung transformations- bzw. tumorspezifischer PCR-Produkte sollte es moeglich sein Tumormarker fuer diagnostische Zwecke zu entwickeln. Die Methode wurde fuer die Analyse von Zellen des Syrischen Hamster aufgebaut, sie ist jedoch universell fuer alle Saeuger anwendbar. (orig.)

  15. Line width and line shape analysis in the inductively coupled plasma by high resolution Fourier transform spectrometry

    International Nuclear Information System (INIS)

    Faires, L.M.; Palmer, B.A.; Brault, J.W.

    1984-01-01

    High resolution Fourier transform spectrometry has been used to perform line width and line shape analysis of eighty-one iron I emision lines in the spectral range 290 to 390nm originating in the normal analytical zone of an inductively coupled plasma. Computer programs using non-linear least squares fitting techniques for line shape analysis were applied to the fully resolved spectra to determine Gaussian and Lorentzian components of the total observed line width. The effect of noise in the spectrum on the precision of the line fitting technique was assessed, and the importance of signal to noise ratio for line shape analysis is discussed. Translational (Doppler) temperatures were calculated from the Gaussian components of the line width and were found to be on the order of 6300 0 K. The excitation temperature of iron I was also determined from the same spectral data by the spectroscopic slope method based on the Einstein-Boltzmann expression for spectral intensity and was found to be on the order of 4700 0 K. 31 references

  16. Radon in coal power plant areas

    International Nuclear Information System (INIS)

    Mauna, Traian; Mauna, Andriesica

    2006-01-01

    Radon, the radioactive colourless and inodorous noble gas, represents more than 55% of the natural average radioactivity. It is permanently released from the soil and majority of building materials, it builds up in the mine galleries, in dwelling houses and in other closed rooms. Radon gained increasingly in importance, particularly after 1990 when was doubtless identified as the second cause of lung cancer if a given concentration threshold is surpassed. This threshold is established differentially by each country as a function of the particular site and generally ranges between 150 Bq.m -3 and 600 Bq.m -3 . The telluric radon consists of two isotopes, 222 Rn, a daughter of radium descending from uranium, which induces 90% of the effects, and 220 Rn from thorium series which have too short a lifetime to count in the risk assessments of radon inhalation. The interest of the authorities and population for diminishing the radon effects was illustrated by specific studies which in USA were managed by the National Counsel of Research, the BEIR VI committee of which has issued a report concerning the lung cancer produced by radon and its descendants. Coal mining, the transport, processing, burning, slag and ash disposal are activities entailing radon release. The miners' dwellings are placed in areas with the high radon potential. The local building materials have a high content of radioactive elements from the uranium or thorium series so that radon can build up in the closed rooms of these buildings. Hence the social responsible authorities in the coal power industry zones should consider this aspect long time ignored in the Balkans macro zone so far. The radon issue must be differentially approached in different areas hence a zonal mapping of the radon emission should be first done. It is worth to underline that the gaseous radioactive emission from operational nuclear power plants amounts up to a few percents of the radon natural emissions what entails a

  17. 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)

  18. Modulating factors in the expression of radiation-induced oncogenic transformation

    International Nuclear Information System (INIS)

    Hall, E.J.; Hei, T.K.

    1990-01-01

    Many assays for oncogenic transformation have been developed ranging from those in established rodent cell lines where morphological alteration is scored, to those in human cells growing in nude mice where tumor invasiveness is scored. In general, systems that are most quantitaive are also the least relevant in terms of human carcinogenesis and human risk estimation. The development of cell culture systems has made it possible to assess at the cellular level the oncogenic potential of a variety of chemical, physical and viral agents. Cell culture systems afford the opportunity to identify factors and conditions that may prevent or enhance cellular transformation by radiation and chemicals. Permissive and protective factors in radiation-induced transformation include thyroid hormone and the tumor promoter TPA that increase the transformation incidence for a given dose of radiation, and retinoids, selenium, vitamin E, and 5-aminobenzamide that inhibit the expression of transformation. Densely ionizing α-particles, similar to those emitted by radon daughters, are highly effective in inducing transformations and appear to interact in a supra-additive fashion with asbestos fibers. The activation of a known dominant oncogene has not yet been demonstrated in radiation-induced oncogenic transformation. The most likely mechanism for radiation activation of an oncogene would be via the production of a chromosomal translocation. Radiation also efficiently induces deletions and may thus lead to the loss of a suppressor gene

  19. Subsurface temporal variation of radon at the Conrad Geophysical Observatory, Austria

    Science.gov (United States)

    Leonhardt, Roman; Steinitz, Gideon; Piatibratova, Oksana

    2015-04-01

    The Conrad Observatory (COBS) housed the national geophysical observatory of Austria and is located 50 km south west of Vienna within the carbonate sequence of the "Wettersteinkalk". Parameters monitored at the facility comprise environmental data, seismic signals, gravity, geomagnetic components and also natural gamma rays. A subsurface tunnel, 150 meters long and oriented E-W is driven into the calcareous sequence at a depth of 50 meters. The tunnel is lined with a concrete carapace, ~20 cm thick. The tunnel observatory is separated from the external atmosphere by 3 tight doors, resulting in a stable temperature of 6.85±0.04°C. A gamma detector (3×3", NaI, SCA) is used measure the variation of the gamma radiation from radon in the air of the tunnel, at a resolution of 1 minute, which is accumulated to form a 15-minute count rate. The sensor is placed on a concrete block at 135 meters. Several SSNTD measurements in the tunnel indicated radon level in the level of 1.5 kBq/m^3. The background gamma radiation, due probably mainly to sources in the concrete is in the order to 2×105 counts (per 15-minutes). A long term variation of radon is reflected as an annual radon signal with large amplitude (2×105 counts) and a maximum in summer. Small to large (2×105 counts) non periodic multi-day signals lasting from two to several tens of days are superimposed. Daily periodic signals of much lower amplitude are observed, with amplitudes generally up to 4×104 counts. The amplitude of the non-periodic multi-day is coupled to amplitude of the annual signal, and the amplitude of the periodic daily signal is modulated by the multi-day variation. The source of the radon in the air of the tunnel is from the concrete lining the floor and walls of the tunnel. The variation patterns and their systematic characteristics cannot be ascribed to local variations of pressure and temperature (stable). These limitations indicate that other driver(s), external to the tunnel, are forcing

  20. Researchers and experts faced with legal issues in radon affairs

    International Nuclear Information System (INIS)

    Massuelle, M.; Pirard, P.; Hubert, P.

    1998-01-01

    In France, radon has emerged as a public health issue mainly at the initiative of scientists. Public authorities are currently considering regulations but for a long time scientists faced the radon issue alone. As a consequence, scientists were involved and are still involved in producing knowledge, in informing about their results, in giving advice to various bodies and individuals, and in participating in the process of technical standardization. These functions are identified in the paper in order to sketch out a typology of different situations, formal and informal, in which researchers transformed into experts are called to collaborate. During their missions related to radon, experts are exposed to 'legal risks', particularly in terms of civil liability or 'professional' responsibility and even criminal responsibility. They face legal difficulties because their roles are not clearly defined. Such difficulties will be also described in this paper, because they are symptomatic of the lack of a legal framework for public scientific expertise. Indeed, there is a growing need to involve scientific experts in decision-making in the field of public health. At the same time, however, there is increased protest against the technocratic nature of public decision-making. We observe an increase in the attribution of blame and penal responsibility in French society, as shown in the 'contaminated blood' case in which not only blood suppliers but also public officials and now politicians have been or are being prosecuted. Radon, which is a domestic risk whose reduction relies entirely on homeowners, is sui generis in many ways. Nevertheless, in an analysis of scientists' roles/actions and of the legal difficulties they meet, radon can be used to illustrate the problems that arise as expertise is developed about new risks. (authors)

  1. Radon adsorption on present activated charcoals

    International Nuclear Information System (INIS)

    Kazankin, Yu.N.; Trofimov, A.M.; Mikhajlova, L.K.

    1978-01-01

    Radon adsorption from helium and air has been studied on modern activated carbons of SKT-1, SKT-2a, SKT-3, SKT-2b, SKT-6, PAU-1 within the temperature range from 100 to 80 deg. It has been shown that PAU-1 carbon has the highest activity with respect to radon in the temperature range studied. With decreasing temperature the adsorption coefficients increase sharply. It has been found that for the case of radon adsorption from helium the logarythm of the Henry coefficient linearly depends on the inverse value of absolute temperature. Adsorption of radon from air is inhibited and the above-cited relationship is deviated from linear. The results of calculating differential heats of radon and air adsorption as well as coefficients of radon and air separation on carbons are presented

  2. NORM and radon in Austria. Status and strategy; Norm und Radon in Oesterreich. Status und Strategie

    Energy Technology Data Exchange (ETDEWEB)

    Maringer, F.J. [Bundesamt fuer Eich- und Vermessungswesen, Wien (Austria)

    2013-07-01

    The author reviews the actual radiation protection practice in Austria for NORM and radon, including possible strategies and developments. Specific topics are radiation protection technologies, metrological resources for NORM in Austria, civil engineering standards (OeNORM) for radon measurement, radon prevention for new buildings and radon cleansing for existing buildings, future assessment and legal regulation of radioactivity in construction materials. The strategic development in Austria considers the current European standard projects (EU standards) and European and international research programs.

  3. Comparative survey of outdoor, residential and workplace radon concentrations

    International Nuclear Information System (INIS)

    Barros, Nirmalla; Field, R. William; Field, Dan W.; Steck, Daniel J.

    2015-01-01

    This study investigated radon concentrations in above-ground (i.e. first floor) workplace in Missouri and compared them with above-ground radon concentrations in nearby homes and outdoor locations. This study also examined the potential utility of using home and outdoor radon concentrations to predict the radon concentration at a nearby workplace (e.g. county agencies and schools). Even though workplace radon concentrations were not statistically different from home radon concentrations, the radon concentration at a particular home, or outdoor location, was a poor predictor of the radon concentration at a nearby workplace. Overall, 9.6 and 9.9 % of homes and workplace, respectively, exhibited radon concentrations of ≥148 Bq m -3 . Because of the percentage of workplace with elevated radon concentrations, the results suggest that additional surveys of workplace radon concentrations are needed, especially in areas of high radon potential, to assess the contribution of workplace radon exposure to an individual's overall radon exposure. (authors)

  4. Application of point-to-point matching algorithms for background correction in on-line liquid chromatography-Fourier transform infrared spectrometry (LC-FTIR).

    Science.gov (United States)

    Kuligowski, J; Quintás, G; Garrigues, S; de la Guardia, M

    2010-03-15

    A new background correction method for the on-line coupling of gradient liquid chromatography and Fourier transform infrared spectrometry has been developed. It is based on the use of a point-to-point matching algorithm that compares the absorption spectra of the sample data set with those of a previously recorded reference data set in order to select an appropriate reference spectrum. The spectral range used for the point-to-point comparison is selected with minimal user-interaction, thus facilitating considerably the application of the whole method. The background correction method has been successfully tested on a chromatographic separation of four nitrophenols running acetonitrile (0.08%, v/v TFA):water (0.08%, v/v TFA) gradients with compositions ranging from 35 to 85% (v/v) acetonitrile, giving accurate results for both, baseline resolved and overlapped peaks. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  5. Reconstruction of national distribution of indoor radon concentration in Russia using results of regional indoor radon measurement programs

    International Nuclear Information System (INIS)

    Yarmoshenko, I.; Malinovsky, G.; Vasilyev, A.; Zhukovsky, M.

    2015-01-01

    The aim of the paper is a reconstruction of the national distribution and estimation of the arithmetic average indoor radon concentration in Russia using the data of official annual 4-DOZ reports. Annual 4-DOZ reports summarize results of radiation measurements in 83 regions of Russian Federation. Information on more than 400 000 indoor radon measurements includes the average indoor radon isotopes equilibrium equivalent concentration (EEC) and number of measurements by regions and by three main types of houses: wooden, one-storey non-wooden, and multi-storey non-wooden houses. To reconstruct the national distribution, all-Russian model sample was generated by integration of sub-samples created using the results of each annual regional program of indoor radon measurements in each type of buildings. According to indoor radon concentration distribution reconstruction, all-Russian average indoor radon concentration is 48 Bq/m"3. Average indoor radon concentration by region ranges from 12 to 207 Bq/m"3. The 95-th percentile of the distribution is reached at indoor radon concentration 160 Bq/m"3. - Highlights: • Reconstruction of indoor radon concentration distribution in Russia was carried out. • Data of official annual 4-DOZ reports were used. • All-Russian average indoor radon concentration is 48 Bq/m"3. • The 95-th percentile is 160 Bq/m"3.

  6. Factors influencing radon attenuation by tailing covers

    International Nuclear Information System (INIS)

    Silker, W.B.; Rogers, V.C.

    1981-07-01

    The US NRC, in its Generic Environmental Impact Statement on uranium milling has specified that the radon flux escaping a uranium mill tailings pile will be reduced to pCi/m 2 s by application of covering layers of soils and clays. These covers present a radon diffusion barrier, which sufficiently increases the time required for radon passage from the tailings to the atmosphere to allow for decay of 222 Rn within the cover. The depth of cover necessary to reduce the escaping radon flux to the prescribed level is to be determined by calculation, and requires precise knowledge of the radon diffusion coefficient in the covering media. A Radon Attenuation Test Facility was developed to determine rates of radon diffusion through candidate cover materials. This paper describes this facility and its application for determining the influence of physical properties of the soil column on the radon diffusion coefficient

  7. 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).

  8. Radon: A health problem

    International Nuclear Information System (INIS)

    Pucci, J.; Gaston, S.

    1990-01-01

    Nurses can and should function as effective teachers about the potential hazards to health of radon contamination in the home as well as become activists in the development of health care policy on radon

  9. Comparative study on radon effects and thermal effects on humans in radon hot spring therapy

    International Nuclear Information System (INIS)

    Yamaoka, K.; Mitsunobu, F.; Hanamoto, K.; Tanizaki, Y.; Sugita, K.; Kohima, S.

    2003-01-01

    Full text: The radon therapy is used radon ( 222 Rn) gas, which mainly emits alpha-rays, and induces a small amount of active oxygen in the body. Because most of the diseases to which the radon therapy as well as the thermal therapy is applied are related to activated oxygen, in this study the effects of the radioactivity of radon and thermal effects were compared under the room or the hot spring condition with the similar chemical component, using as the parameters which are closely involved in the clinical for radon therapy. In the results, the radon and thermal therapy enhanced the antioxidation function, such as the activities of superoxide dismutase (SOD) and catalase, which inhibit lipid peroxidation and total cholesterol produce in the body. Moreover the therapy enhanced concanavalin A (ConA)-induced mitogen response, and increased the level of CD4, which is the marker of helper T cell, and decreased the level of CD8, which is the common marker of killer T cell and supresser T cell, in the white cell differentiation antigen (CD4/CD8) assay. Furthermore, the therapy increased the levels of alpha atrial natriuretic polypeptide (alpha ANP), beta endorphin, adrenocorticotropic hormone (ACTH), insulin and glucose-phosphate dehydrogenase (G-6-PDH), and decreased the vasopression level. The results were on the whole larger in the radon group than in the thermal group. The findings suggest that the radon therapy more contributes to the prevention of life style-related diseases related to peroxidation reactions and immune depression than thermal therapy. Moreover these indicate what may be a part of the mechanism for the alleviation of hypertension, osteoarthritis (pain) and diabetes mellitus brought about more radon therapy than thermal therapy

  10. The matter of radon

    International Nuclear Information System (INIS)

    O'Riordan, M.C.; O'Riordan, C.N.

    1992-01-01

    By comparison with the radiation doses from radon, the doses to individual members of the public and to the general community from nuclear activities are quite trivial. Doses from radon in some British homes exceed the statutory dose limit for nuclear workers;the collective dose from radon is two thousand times the value for nuclear discharges. And yet, too little attention - legal or otherwise - is paid to this radioactive pollutant. An attempt is made in this paper to compensate for the neglect. The origins, properties and harmful effects of radon are described. Measurements in homes and places of work are summarised. Voluntary and regulatory controls on exposure are elucidated. Questions of public administration, confidentiality of information and sale of property are discussed. Prospects for progress are assessed. (author)

  11. Passive radon daughter dosimeters

    International Nuclear Information System (INIS)

    McElroy, R.G.C.; Johnson, J.R.

    1986-03-01

    On the basis of an extensive review of the recent literature concerning passive radon daughter dosimeters, we have reached the following conclusions: 1) Passive dosimeters for measuring radon are available and reliable. 2) There does not presently exist an acceptable passive dosimeter for radon daughters. There is little if any hope for the development of such a device in the foreseeable future. 3) We are pessimistic about the potential of 'semi-passive dosimeters' but are less firm about stating categorically that these devices cannot be developed into a useful radon daughter dosimeter. This report documents and justifies these conclusions. It does not address the question of the worker's acceptance of these devices because at the present time, no device is sufficiently advanced for this question to be meaningful. 118 refs

  12. Experimental study of gene expression in lung and bronchus of radon-exposed mice

    International Nuclear Information System (INIS)

    Guo Zhiying; Tian Mei; Liu Jianxiang; Ruan Jianlei; Piao Chunnan; Su Xu

    2008-01-01

    Objective: To construct and identify differentially expressed cDNA library in lung and bronchus of mice exposed to radon. Methods: 2 week old, weighing (18-22)g, male BALB/c mice were placed in a SR-NIM02 radon chamber. One group of mice was exposed to radon, which was equivalent to the accumulative dose of 30 WLM. The control group was about 0.02 WLM. To construct a subtracted cDNA library enriched with differentially expressed genes, the Super SMART technique and the suppression subtractive hybridization (SSH) were performed. The obtained forward and reverse cDNA fragments were directly inserted into pGEM-T-easy vector and transformed into E. coli DH5α. The inserts in plasmid were amplified by nested polymerase chain reaction (PCR), and some of which were sequenced. In the end these sequences were BLASTed with GeneBank. Results: 146 of 460 clones obtained randomly were positive clones contained (1000-1500)bp inserted cDNA fragments. The forward and reverse subtracted cDNA library in lung and bronchus of mice exposed to radon was constructed, and 48 up-regulation and 61 down-regulation cDNA sequences selected were homologous with GeneBank in different extent. Conclusions: The subtracted cDNA library in lung and bronchus of mice exposed to radon is successfully constructed, and genes that differentially expressed are identified. Some genes might have relation with the immunity, cell cycle and apoptosis. (authors)

  13. Radon levels in Croatian spas

    International Nuclear Information System (INIS)

    Radolic, V.; Vukovic, B.; Stanic, D.; Planinic, J.

    2005-01-01

    Average radon concentrations in the air and geothermal water of spa pools in Croatia were 40.3 Bq/m 3 and 4.5 kBq/m 3 , respectively. Substantial difference between radon concentrations in pool and spring water is explained by the mixing normal and geothermal water in the pool and with radon decay. The estimated annual effective dose received by the personnel in the spa of Stubicke toplice, Croatia was 0.7 mSv. At the same location, the calculated transfer factor of radon for the air and thermal water in the pool was 4.9x10 -3 .(author)

  14. Application of CR-39 to radon measurement

    International Nuclear Information System (INIS)

    Miyake, Hiroshi

    1988-01-01

    CR-39, an ally diglycol carbonate, has recently come into wider use as material for solid-state track detector. Etching with NaOH or KOH solution allow CR-39 to develop extremely clear etch pits attributed to alpha rays. The most widely used method for measuring radon concentration employs a plastic cup with a solid-state track detector mounted at its bottom to detect alpha rays resulting from radon or its daughters that disintegrate within or on the wall of the cup. Simple in mechanism and low in cost, this method is suitable for such a case where the radon concentration distribution over a wide area has to be measured by using a large number of devices. The concentration of radon alone can be measured with the aid of a filter attached to the mouth of the cup to remove the daughters of radon and thoron. The simplest and most effective way of improving the sensitivity of a solid-state track detector for radon concentration measurement is to electrostatically collect daughters resulting from decay of radon onto the surface of the detector. Another method widely used to determine the radon concentration is to measure the concentration of the radon daughters instead of direct measurement of the concentration of radon itself. (Nogami, K.)

  15. Optimized transmission-line impedance transformers for petawatt-class pulsed-power accelerators

    Directory of Open Access Journals (Sweden)

    D. R. Welch

    2008-03-01

    Full Text Available We have developed 1D analytic and 2D fully electromagnetic models of radial transmission-line impedance transformers. The models have been used to quantify the power-transport efficiency and pulse sharpening of such transformers as a function of voltage pulse width and impedance profile. For the cases considered, we find that in the limit as Γ→0 (where Γ is the ratio of the pulse width to the one-way transit time of the transformer, the transport efficiency is maximized when the impedance profile is exponential. As Γ increases from zero, the optimum profile gradually deviates from an exponential. A numerical procedure is presented that determines the optimum profile for a given pulse shape and width. The procedure can be applied to optimize the design of impedance transformers used in petawatt-class pulsed-power accelerators.

  16. Training and Accreditation for Radon Professionals in Sweden

    International Nuclear Information System (INIS)

    Soderman, A. L.

    2003-01-01

    Radon training courses and seminars of different kinds have been arranged in Sweden since the early 1980s. A commercial educational company initiated the first regular training courses in 1987. Up to 1990 about 400 persons had attended courses in radon measurement and radon mitigation methods. In 1991 the first in a series of courses focussed on radon from the ground and production of radon risk maps organised. From 1991 it has been possible to obtain accreditation for measurements of indoor radon in Sweden and from 1997 also for measurements of radon in water. Even if accreditation s is voluntary, in Sweden accredited laboratories perform most measurements, both for indoor air and water. A condition for accreditation in to have passed the examination following the training courses at SSI, SO far, three major companies have obtained accreditation for measurement of indoor radon and four have been accredited for measurements of radon in water. Education on radon is also given at universities and institutes of technology. A two-day course is included in the education for environmental health officers. A number of training courses aimed at real state agents have been organised by SSI through the years. During the autumn of 2001 altogether 400 authorised real estate agents attended a series of regional half-day courses. In 1995 SSI arranged an international training course, Radon Indoor Risk and Remedial Actions, in Stockholm for the European commission. About 40 scientists from all over Europe attended the course, which much appreciated by the participants. Today SSI's Radon Training Programme comprises five different courses, a Basic radon Course and four continuation courses: Radon measurements, Radon remedial measures, Radon in water and Radon investigation and risk map production. The courses are arranged twice a year, in spring and autumn, except the Radon risk map production course, which is arranged about every second year. Altogether, between 1991 and 2003

  17. A statistical evaluation of the geogenic controls on indoor radon concentrations and radon risk

    Energy Technology Data Exchange (ETDEWEB)

    Appleton, J.D., E-mail: jda@bgs.ac.u [British Geological Survey, Kingsley Dunham Centre, Nicker Hill, Keyworth, Nottingham, NG12 5GG (United Kingdom); Miles, J.C.H. [Health Protection Agency (HPA), Radiation Protection Division, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom)

    2010-10-15

    ANOVA is used to show that approximately 25% of the total variation of indoor radon concentrations in England and Wales can be explained by the mapped bedrock and superficial geology. The proportion of the total variation explained by geology is higher (up to 37%) in areas where there is strong contrast between the radon potential of sedimentary geological units and lower (14%) where the influence of confounding geological controls, such as uranium mineralisation, cut across mapped geological boundaries. When indoor radon measurements are grouped by geology and 1-km squares of the national grid, the cumulative percentage of the variation between and within mapped geological units is shown to be 34-40%. The proportion of the variation that can be attributed to mapped geological units increases with the level of detail of the digital geological data. This study confirms the importance of radon maps that show the variation of indoor radon concentrations both between and within mapped geological boundaries.

  18. 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)

  19. Biological radiation effects of Radon in Drosophila; Efectos biologicos del radon en Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel P, A E

    1996-12-31

    In order to contribute to the knowledge on the effects of radon and its decay products, the aim of this investigation is to study the biological effects of radon using Drosophila melanogaster throught the somatic mutation and recombination test (SMART) and the analysis of some adaptative factors exposing larvaes to controlled radon atmosphers, considering that this insect could be used as biological monitor. Using the somatic mutation test a mutagenic effect was observed proportional to radon concentration, into an interval of 1 {+-} 0.3 to 111 {+-} 7.4 KBq/m{sup 3} equivalent to doses under 0.0106 Gy. The correlation analysis gives a linear (r=0.80) relationship with a positive slope of 0.2217. The same happens when gamma rays are used in the interval of 1 to 20 Gy, given a linear dose-dependent effect (r=0.878) is obtained; nevetheless the slop is smaller (m=0.003) than for radon. Analysing the results of adaptative factors of the nine exposed generations, it was found that probably radon exposition induced dominant lethals during gametogenesis or/and a selection of the more component gamets of the treated individuals in larval state. It was reflected in the significant decrease on fecundity of the generation exposed. Nevertheless the laying eggs had an increase in egg-to-adult viability and the develop velocity was higher than in control for 3 KBq/m{sup 3}, this suggest that radon concentrations used were able to induce repair mechanisms. These data agree with the Hormesis hypothesis that says: low doses have positive effects on health. It was not possible to obtain a dose-effect relationship except with the develop velocity where it was found a dose-effect inverse proportion. In conclusion, Drosophila melanogaster could be a good system to obtain in vivo damaged induction concentration dependent of radon and its decay products, as well as to study the effects in an exposed population by the analysis of adaptative factors. (Author).

  20. 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 and a summary of this work is discussed. This work showed that the system performs very effectively over a range of operating conditions similar to those found in a home. The field test data that is presented shows that scale up from the laboratory work was without problem and the units are functioning as expected. This unit provides homeowners and mitigation contractors with another option to solve the radon gas problem in homes, particularly in homes that it is difficult to prevent radon from entering

  1. 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

  2. Indoor radon concentrations in Vushtrri, Kosovo

    International Nuclear Information System (INIS)

    Xhafa, B.; Jonuzaj, A.; ); Bekteshi, S.; Ahmetaj, S.; Kabashi, S.; )

    2009-01-01

    Indoor air radon concentration was measured by exposing trac ketch detectors in the two elementary schools, one high school, a kindergarten and the hospital in the city of Vushtrri. Measurements were performed with the radon monitor PRM-145, which uses alpha scintillation cells and serves to determine the current concentration of radon. The results we obtained are in the range between the average values of radon for the interior spaces, and values that pose a potential risk for lung cancer. Measuring the concentration of radon was done in total of 34 rooms and came up with values which are between 28Bqm -3 and 398Bqm -3 . In order to reduce the concentration of radon, we have built a ventilation pump, then we performed repeated measurements and finally came with results between 130-145Bqm -3 .

  3. Radon reduction in crawl-space houses

    International Nuclear Information System (INIS)

    Osborne, M.C.; Moore, D.G.; Southerlan, R.E.; Brennan, T.; Pyle, B.E.

    1989-01-01

    This paper gives results of an EPA study of radon-mitigation alternatives for crawl space houses in several houses in Nashville, TN. Application of one of these alternative mitigation options, suction under a polyethylene membrane, has been successful in significantly reducing radon levels in both the crawl space and the house. The large radon concentrations measured under unvented plastic ground covers and the moisture barriers found in many crawl spaces can act as radon-rich reservoirs capable of contaminating a crawl space and house during periods of depressurization. With the exhaust components of the mitigation system in place, radon levels below the plastic decreased by more than 95% under both passive and active suction conditions. Based on the study, the design of a cost-effective subplastic suction passive radon mitigation system for crawl spaces seems promising

  4. Characterization of radon levels in indoor air

    International Nuclear Information System (INIS)

    George, A.C.

    1982-01-01

    The purpose is to describe the different types of monitoring and sampling techniques that can determine the radiation burden of the general public from radon and its decay products. This is accomplished by measuring the range and distribution of radon and radon decay products through broad surveys using simple and convenient integrating monitoring instruments. For in-depth studies of the behavior of radon decay products and calculation of the radiation dose to the lung, fewer and more intensive and complex measurements of the particle size distribution and respiratory deposition of the radon decay products are required. For diagnostic purposes, the paper describes measurement techniques of the sources and exhalation rate of radon and the air exchange inside buildings. Measurement results form several studies conducted in ordinary buildings in different geographical areas of the United States, using the described monitoring techniques, indicate that the occupants of these buildings are exposed to radon and radon decay product concentrations, varying by as much as a factor of 20

  5. An overview of Ireland's National Radon Policy

    International Nuclear Information System (INIS)

    Long, S.; Fenton, D.

    2011-01-01

    In Ireland radon is a significant public health issue and is linked to 150-200 lung cancer deaths each year. Irish National Radon Policy aims to reduce individual risk by identifying and remediating buildings with high radon concentrations and also to reduce collective dose through radon prevention as required by revised building regulations. Achievements to date are significant and include the completion of the National Radon Survey, the testing of every school in Ireland, the on-going testing of social housing, collaboration between the public health and radiation protection authorities and the inclusion of radon in inspections of workplaces. However, this work now needs to be drawn together centrally to comprehensively address the radon problem. The RPII and the relevant central governing department, the Dept. of Environment, Heritage and Local Government are currently working to constitute a group of key experts from relevant public authorities to drive the development of a National Radon Control Strategy. (authors)

  6. Measuring your radon risk

    International Nuclear Information System (INIS)

    Mackmurdo, R.

    1994-01-01

    In its annual report for 1992/93, the NRPB has warned that tens of thousands of UK employees may be exposed to high levels of radon at work. In addition to those who work underground, employees at risk of radon-induced lung cancer are typically those who spend long periods indoors. This article reviews the implications for all employers especially those in low or unknown levels of radon who resist taking measurements in the belief that by not measuring, they are not liable. (UK)

  7. Generation of doubled haploid transgenic wheat lines by microspore transformation.

    Directory of Open Access Journals (Sweden)

    Rhoda A T Brew-Appiah

    Full Text Available Microspores can be induced to develop homozygous doubled haploid plants in a single generation. In the present experiments androgenic microspores of wheat have been genetically transformed and developed into mature homozygous transgenic plants. Two different transformation techniques were investigated, one employing electroporation and the other co-cultivation with Agrobacterium tumefaciens. Different tissue culture and transfection conditions were tested on nine different wheat cultivars using four different constructs. A total of 19 fertile transformants in five genotypes from four market classes of common wheat were recovered by the two procedures. PCR followed by DNA sequencing of the products, Southern blot analyses and bio/histo-chemical and histological assays of the recombinant enzymes confirmed the presence of the transgenes in the T0 transformants and their stable inheritance in homozygous T1∶2 doubled haploid progenies. Several decisive factors determining the transformation and regeneration efficiency with the two procedures were determined: (i pretreatment of immature spikes with CuSO4 solution (500 mg/L at 4°C for 10 days; (ii electroporation of plasmid DNA in enlarged microspores by a single pulse of ∼375 V; (iii induction of microspores after transfection at 28°C in NPB-99 medium and regeneration at 26°C in MMS5 medium; (iv co-cultivation with Agrobacterium AGL-1 cells for transfer of plasmid T-DNA into microspores at day 0 for <24 hours; and (v elimination of AGL-1 cells after co-cultivation with timentin (200-400 mg/L.

  8. Determination of equilibrium factor between radon and its progeny using surface barrier detector for various shapes of passive radon dosimeters

    International Nuclear Information System (INIS)

    Jamil, K.; Fazal-ur-Rehman; Ali, S.; Khan, H.A.

    1997-01-01

    In the field of radon dosimetry, it is customary to measure radon ( 222 Rn) concentration while potential health hazard is due to the radon short-lived progeny. When radon is in secular equilibrium, the measured activity of radon equals the activity of radon's progeny. However, in practical cases an inequilibrium between radon and its progeny exists which is measured in terms of the equilibrium factor. To determine the equilibrium factor between radon and its progeny in a closed environment various shapes of passive dosimeters based upon solid state nuclear track detectors (SSNTDs) are employed. In order to observe the dependence of equilibrium factor upon shapes or effective volumes, experiments have been performed replacing the SSNTDs with a surface barrier detector in Karlsruhe diffusion chamber, pen-type and box-type dosimeters. Using the collected alpha spectra, the equilibrium factor has been determined for a radon-air mixture in a custom designed radon chamber simulating a closed environment of a room. The results show that the radon equilibrium factor is about 0.20 for different shapes of dosimeters studied in this research. It is concluded that the determination of equilibrium factor between radon and its progeny does not depend upon effective volume or shape of the passive dosimeters using alpha spectroscopic data acquired by surface barrier detector. (orig.)

  9. Radon in the indoor environment

    International Nuclear Information System (INIS)

    Vanmarcke, H.

    1998-01-01

    A precise retrospective assessment of long-term radon exposures in dwellings is essential for estimating lung-cancer risks. The objectives of this research are (1) to investigate the deposition of radon progeny in the human respiratory tract by means of direct measurements as a function of aerosol conditions, (2) to assess the radon concentrations in buildings retrospectively with volume traps

  10. Radon in the indoor environment

    International Nuclear Information System (INIS)

    Vanmarcke, H.

    1998-01-01

    The objectives of R and D on radon in the indoor environment at SCK-CEN is to (1) to investigate the deposition of radon progeny in the human respiratory tract by means of direct measurements as a function of aerosol conditions; to assess the radon concentrations in buildings retrospectively with volume traps. Progress and main achievements in 1997 are reported on

  11. Emission of radon from soil

    International Nuclear Information System (INIS)

    Ahlberg, P.; Lindmark, A.; Rosen, B.

    1980-03-01

    The report deals with the measurement of radon daughters in the soil Radon migrates readily through the limestone which is superpositioned the alum shale. The level of gamma radiation is normal. Measurements have been made by the track etch technique and with Kodak film. The contents of radon daughters are shown to be due to the measuring depth. (G.B.)

  12. 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)

  13. Radon and radon daughters' concentration in spring and wells waters from Presidente Prudente: preliminary results

    International Nuclear Information System (INIS)

    Osorio, Ana Maria Araya; Saenz, Carlos Alberto Tello; Pereira, Luiz Augusto Stuani

    2009-01-01

    This work presents the preliminary results about the concentration of radon and radon daughters in wells and springs water from Presidente Prudente. Six water samples were studied: three from well-water, two from springs water and one from potable water. For the determination of α-activity the samples were placed inside plastic containers where the CR-39 tracks detectors were outside the water. The track density of α-particles were measured by using optical microscopy. The results show that one sample from well-water presented higher concentration of radon and radon daughters than the other samples. (author)

  14. Radon in dwellings the national radon survey Cavan, Dublin, Louth, Monaghan and Wicklow

    International Nuclear Information System (INIS)

    Duffy, J.T.; Mackin, G.M.; Fennell, S.G.; Madden, J.S.; McGarry, A.T.; Colgan, P.A.

    1996-10-01

    This report presents the first results of the National Radon Survey carried out by the Radiological Protection Institute of Ireland. The average radon concentrations for the houses measured in counties Cavan, Dublin, Louth, Monaghan and Wicklow ranged from 69 to 138 Bq/m 3 with individual values as high as 1000 Bq/m 3 . The measurement data were grouped on the basis of the 10 km grid squares of the Irish National Grid System and used to predict the percentage of dwellings in each grid square which exceeds the Reference Level of 200 Bq/m 3 . Grid squares where this percentage is predicted to be 10% or higher are designated High Radon Areas. The health effects of exposure to high radon levels are discussed and recommendations are made regarding both new and existing dwellings

  15. Training and accreditation for radon professionals in Sweden

    International Nuclear Information System (INIS)

    Mjoenes, L.; Soederman, A.-L.

    2004-01-01

    Radon training courses and seminars on radon have been arranged in Sweden since the early 1980s. A commercial educational company initiated the first regular training courses in 1987. Up to 1990 about 400 persons had attended courses in radon measurement and radon mitigation methods. In 1991 the training programme was taken over by the Swedish Radiation Protection Authority, SSI. Today SSI's Radon Training Programme comprises three different two-day courses, a Basic Radon Course and two continuation courses: Radon Measurements and Radon in Water. Until 2003 SSI also arranged courses about Radon Remedial Measures and Radon Investigation and Risk Map Production. The courses are arranged twice a year. Altogether, about 750 municipal environmental health officers and technicians from private companies have been educated in the SSI training programme between 1991 and 2003. The continuation courses are completed with an examination, consisting of a theoretical test. The names of the persons who pass are being published in a list that is found on the SSI web site. Since no certification system is currently in place for radon professionals in Sweden, this list helps people who need to get in contact with radon counsellors to find one in their area and is used by authorities as well as private house-owners. Since 1991 it has been possible to obtain accreditation for measurements of indoor radon in Sweden and since 1997, also for measurements of radon in water. Although accreditation is voluntary in Sweden, accredited laboratories perform most measurements, both for indoor air and water. Passing the examination in the SSI training courses is a condition for accreditation. The Swedish Board for Accreditation and Conformity Assessment, SWEDAC, is in charge of the accreditation. So far, three major companies have obtained accreditation for measurement of indoor radon and four have been accredited for measurements of radon in water

  16. Construction and identification of subtracted cDNA library in bone marrow cells of radon-exposed mice

    International Nuclear Information System (INIS)

    Li Jianxiang; Nie Jihua; Tong Jian; Fu Chunling; Zhou Jianwei

    2008-01-01

    Objective: To construct and identify subtracted cDNA library in bone marrow cells of mice exposed to radon inhalation. Methods: Adult male BALB/c mice, weighing 18-22 g, were placed in a multi- functional radon chamber. One group of mice was exposed to radon up to the accumulative dose of 105 work level month (WLM). The control group of mice was housed in a room with an accumulative dose of 1 WLM. To construct a subtracted cDNA library enriched with differentially expressed genes, the SMART technique and the suppression subtractive hybridization were performed. The obtained forward and reverse cDNA fragments were directly inserted into pMD18-T vector and transformed into E. coli JM109. The inserting cDNA fragments were screened by the blue-and-white blot screening and nested PCR of bacterium liquid. Results: The 244 of 285 white bacteria clones obtained randomly were positive clones contained 100-1100 bp inserted cDNA fragments. Conclusions: The forward and reverse subtracted cDNA library in bone marrow cells of mice exposed to radon inhalation is successfully constructed. (authors)

  17. The 8-GeV transfer line injection into main ring

    International Nuclear Information System (INIS)

    Yang, M.J.

    1995-06-01

    Included in this report are a brief review of the design lattice of the 8-GeV beam transfer line and the Main Ring, the recent measurements on the 8-GeV line lattice function as well as that of the Main Ring at 8-GeV. The injection matching is a very important part of the MR operation. Mismatches such as energy, timing, or position are easily corrected because they cause oscillations which are visible on the Turn-By-Turn (TBT) TV monitor display. Mis-matches due to beta and dispersion functions are detected only by using the Flying Wire or by doing measurements during beam study. A new method which makes use of the available data from TBT hardware was used to obtain the beam phase space ellipse. Data taken from Main Ring at injection gives the beta function needed for transfer matching from 8-GeV line. The result of this measurement is also presented here

  18. 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

  19. Protocol Implementation for Radon Concentration Measurements in Houses in Croatia - Baranja Case

    International Nuclear Information System (INIS)

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

    2011-01-01

    The newly established protocol for radon measurements in homes was implemented on the radon survey in houses of Baranja region which was carried out from July 2009 until July 2010. The radon measurements were performed with passive track etched detectors. The method consists of cylindrical plastic vessel and two strippable LR-115 films type II (Kodak-Path, France). This method with two detector films enables the estimation of equilibrium factor as well.Croatian territory is divided in 10 x 10 km 2 cells which were part of a reference grid map which is used in a preparation of European radon concentration map. Detector locations were randomly chosen inside each grid and their number was determined by the number of inhabitants inside (one locations per 350 inhabitants). Radon detectors were exposed for a year in a living room or a bedroom away from strong ventilation and 30 cm from side walls (usually on closet at height of 2 m). After the exposure, detectors were collected and etched in 10 % NaOH aqueous solution at 50 degrees of C for 180 minutes. The tracks were automatically counted using spark counter AIST-2V. The obtained results were in the range from 6 to 355 Bq m -3 with arithmetic mean of 88 Bq m -3 and standard deviation of 69.0 Bq m -3 . The geometric mean was 67.2 Bq m -3 while the geometric standard deviation was 2.1 Bq m -3 . The statistical χ2 -test showed that the empirical frequency distribution for radon in houses of Baranja region belonged to the log-normal distribution. The percentage of houses with radon concentrations between 200 and 400 Bq m -3 was 6.7% and 1.0% of houses have radon concentration above 400 Bq m -3 . The annual effective dose from the indoor radon and its short-lived progenies for the inhabitants of Baranja region (for the average equilibrium factor of 0.53 and occupancy factor of 0.6) was 1.5 mSv. (author)

  20. A survey on radon reduction efficiency of zeolite and bentonite in a chamber with artificially elevated radon concentration

    International Nuclear Information System (INIS)

    Mortazavi, S.M.J.

    2007-01-01

    Complete text of publication follows. Objective: Zeolite which is made of a special crystalline structure is a naturally occurring mineral group and can be used in radioactive waste management for site remediation /decontamination. There are a wide variety of naturally occurring and synthetic zeolites, each with a unique structure. The cations in zeolite are highly mobile and can be exchanged for other cationic species. On the other hand, bentonite forms from weathering of volcanic ash. This material may be used as an engineering barrier to enclose nuclear waste. In this study, radon reducing properties of zeolite and bentonite have been investigated. Methods: Using radioactive lantern mantle, a radon prone area with radon levels reaching the EPA's action level (200 Bq/m 3 ) was designed. Two sets of identical chambers (cylindrical chambers, diameter 10 cm, height 16 cm) were used in this study. No zeolite/bentonite was used in the 1 st set of the chambers. A thin layer of either zeolite or bentonite powder was applied to the base of the first set of chambers. An unburned radioactive lantern mantle (activity 800 Bq) was placed in all chambers (both sets) to artificially increase the radon level inside the chamber and simulate the condition of a radon prone area. Radon level monitoring was performed by using a PRASSI portable radon gas survey meter. Results: After placing the cap on its place, the radon levels inside the 1 st set of the chambers were 871.9, 770.3, 769.2 and 635.7 Bq/m 3 after 15, 30, 45 and 60 minutes respectively. Zeolite significantly decreased the radon concentration inside the chambers and radon levels were 367.9, 435.4, 399.0 and 435.4 Bq/m 3 after 15, 30, 45 and 60 minutes. The observed reduction in the radon level was statistically significant. As the radon concentrations in identical chambers with Bentonite were 550.7, 526.5, 536.2 and 479.8 Bq/m 3 after 15, 30, 45 and 60 minutes respectively, it is evident that zeolite is more efficient in

  1. Neoplastic transformation induced by carbon ions.

    Science.gov (United States)

    Bettega, Daniela; Calzolari, Paola; Hessel, Petra; Stucchi, Claudio G; Weyrather, Wilma K

    2009-03-01

    The objective of this experiment was to compare the oncogenic potential of carbon ion beams and conventional photon beams for use in radiotherapy. The HeLa X human skin fibroblast cell line CGL1 was irradiated with carbon ions of three different energies (270, 100, and 11.4 MeV/u). Inactivation and transformation data were compared with those for 15 MeV photons. Inactivation and transformation frequencies for the 270 MeV/u carbon ions were similar to those for 15-MeV photons. The maximal relative biologic effectiveness (RBE(alpha)) values for 100MeV/u and 11.4 MeV/u carbon ions, respectively, were as follows: inactivation, 1.6 +/- 0.2 and 6.7 +/- 0.7; and transformation per surviving cell, 2.5 +/- 0.6 and 12 +/- 3. The curve for dose-transformation per cell at risk exhibited a maximum that was shifted toward lower doses at lower energies. Transformation induction per cell at risk for carbon ions in the entrance channel was comparable to that for photons, whereas for the lower energies, 100 MeV/u and 11 MeV/u, which are representative of the energies delivered to the tumor margins and volume, respectively, the probability of transformation in a single cell was greater than it was for photons. In addition, at isoeffective doses with respect to cell killing, the 11.4-MeV/u beam was more oncogenic than were photons.

  2. Study of cancer cell lines with Fourier transform infrared (FTIR)/vibrational absorption (VA) spectroscopy

    DEFF Research Database (Denmark)

    Uceda Otero, E. P.; Eliel, G. S. N.; Fonseca, E. J. S.

    2013-01-01

    In this work we have used Fourier transform infrared (FTIR) / vibrational absorption (VA) spectroscopy to study two cancer cell lines: the Henrietta Lacks (HeLa) human cervix carcinoma and 5637 human bladder carcinoma cell lines. Our goal is to experimentally investigate biochemical changes...

  3. 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.

  4. Fast and Scalable Computation of the Forward and Inverse Discrete Periodic Radon Transform.

    Science.gov (United States)

    Carranza, Cesar; Llamocca, Daniel; Pattichis, Marios

    2016-01-01

    The discrete periodic radon transform (DPRT) has extensively been used in applications that involve image reconstructions from projections. Beyond classic applications, the DPRT can also be used to compute fast convolutions that avoids the use of floating-point arithmetic associated with the use of the fast Fourier transform. Unfortunately, the use of the DPRT has been limited by the need to compute a large number of additions and the need for a large number of memory accesses. This paper introduces a fast and scalable approach for computing the forward and inverse DPRT that is based on the use of: a parallel array of fixed-point adder trees; circular shift registers to remove the need for accessing external memory components when selecting the input data for the adder trees; an image block-based approach to DPRT computation that can fit the proposed architecture to available resources; and fast transpositions that are computed in one or a few clock cycles that do not depend on the size of the input image. As a result, for an N × N image (N prime), the proposed approach can compute up to N(2) additions per clock cycle. Compared with the previous approaches, the scalable approach provides the fastest known implementations for different amounts of computational resources. For example, for a 251×251 image, for approximately 25% fewer flip-flops than required for a systolic implementation, we have that the scalable DPRT is computed 36 times faster. For the fastest case, we introduce optimized just 2N + ⌈log(2) N⌉ + 1 and 2N + 3 ⌈log(2) N⌉ + B + 2 cycles, architectures that can compute the DPRT and its inverse in respectively, where B is the number of bits used to represent each input pixel. On the other hand, the scalable DPRT approach requires more 1-b additions than for the systolic implementation and provides a tradeoff between speed and additional 1-b additions. All of the proposed DPRT architectures were implemented in VHSIC Hardware Description Language

  5. 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

  6. Comparative study of radon exposure in Canadian homes and uranium mines - a discussion on the importance of national radon program

    International Nuclear Information System (INIS)

    Chen, Jing

    2017-01-01

    The history of lung cancer in uranium miners is well known for over hundreds of years when the disease was referred to as 'miner's disease' or 'mountain sickness'. Radon levels in uranium mines have decreased significantly over the past 30 years as a result of effective radiation protection measures at workplaces. For the most recent 10-year period, the average radon concentrations to underground and surface workers in Canadian uranium mines were 111 and 11 Bq m -3 , respectively. Based on the recent radon survey carried out in roughly 14 000 homes in 121 health regions across Canada and the more recent radon and thoron survey in 33 Canadian cities and 4000 homes, the average radon concentration in Canadian homes is 77 Bq m -3 . This study demonstrates that, nowadays, workers are exposed to radon in underground mines at a comparable radon level to what Canadians are exposed to at home. Since exposure to indoor radon is the main source of natural radiation exposure to the population, it is important for the National Radon Program to further increase radon awareness, and to encourage more Canadians to take appropriate actions to reduce radon exposure. (authors)

  7. Radon as a groundwater tracer in Forsmark and Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Grolander, Sara

    2009-10-15

    Radon concentrations were measured in different water types in Forsmark and Laxemar during the site investigation and within this study. From these measurements it can be concluded that large differences between surface water, near surface groundwater and deep groundwater can be found in both Laxemar and Forsmark. The differences in radon concentrations between different water types are used in this study to detect interactions between surface water, near surface water and deep groundwater. From the radon measurements it can also be concluded that radon concentration in deep groundwater varies largely with depth. These variations with depth are probably caused by groundwater flow in conductive fracture zones in the bedrock. The focus of this study has been the radon concentration of near surface groundwater and the interaction between near surface groundwater and deep groundwater. Radon measurements have been done using the RAD-7 radon detector within this study. It could be concluded that RAD-7 is a good technique for radon measurements and also easy to use in field. The radon concentrations measured in near surface groundwater in Laxemar within this study were low and homogenous. The variation in radon concentration has been analyses and compared to other parameters. Since the hypothesis of this study has been that there are differences in radon concentrations between recharging and discharging groundwater, the most important parameter to consider is the recharge/discharge field classification of the wells. No correlation between the recharge/discharge classifications of wells and the radon concentrations were found. The lack of correlation between groundwater flow patterns and radon concentration means that it is not possible to detect flow patterns in near surface groundwater using radon as a tracer in the Laxemar area. The lack of correlation can be caused by the fact that there are just a few wells located in areas classified as recharge area. It can also be

  8. Effect of heat treatment on transformation behavior of Ti-Ni-V shape memory alloy

    International Nuclear Information System (INIS)

    He Zhirong; Liu Manqian

    2011-01-01

    Highlights: → New shape memory alloy (SMA) - Ti-50.8Ni-0.5V SMA. → The evolution laws of transformation types of annealed Ti-50.8Ni-0.5V SMA. → The evolution laws of transformation types of aged Ti-50.8Ni-0.5V SMA. → The effect laws of annealing on transformation temperature and hysteresis of the alloy. → The effect laws of aging on transformation temperature and hysterises of the alloy. - Abstract: Effects of annealing and aging processes on the transformation behaviors of Ti-50.8Ni-0.5V (atomic fraction, %) shape memory alloy were investigated by means of differential scanning calorimetry (DSC). The A → R/R → A (A - parent phase, R - R phase) type one-stage reversible transformation occurs in 350-400 deg. C annealed alloy, the A → R → M/M → R → A (M - martensite) type two-stage transformation occurs in 450-500 deg. C annealed alloy, the A → R → M/M → A type transformation occurs in 550 deg. C annealed alloy, and A → M/M → A type transformation occurs in the alloy annealed at above 600 deg. C upon cooling/heating. The transformation type of 300 deg. C aged alloy is A → R/R → A, and that of 500 deg. C aged alloy is A → R → M/M → A, while that of 400 deg. C aged alloy changes from A → R/R → A to A → R → M/M → R → A with increasing aging time. The effects of annealing and aging processes on R and M transformation temperatures and temperature hysteresis are given. The influence of annealing and aging temperature on transformation behaviors is stronger than that of annealing and aging time.

  9. Marys Lake 69/115-kV transmission line upgrade and substation expansion projects

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    Western Area Power Administration (Western) and the Platte River Power Authority (Platte River) propose to upgrade portions of the existing electric transmission and substation system that serves the Town of Estes Park, Colorado. The existing transmission lines between the Estes Power Plant Switchyard and the Marys Lake Substation include a 115,000 volt (115-kV) line and 69,000 volt (69-kV) line. Approximately one mile is a double-circuit 115/69-kV line on steel lattice structures, and approximately two miles consists of separate single-circuit 115-kV and a 69-kV lines, constructed on wood H-Frame structures. Both lines were constructed in 1951 by the US Bureau of Reclamation. The existing transmission lines are on rights-of-way (ROW) that vary from 75 feet to 120 feet and are owned by Western. There are 48 landowners adjacent to the existing ROW. All of the houses were built adjacent to the existing ROW after the transmission lines were constructed. Upgrading the existing 69-kV transmission line between the Marys Lake Substation and the Estes Power Plant Switchyard to 115-kV and expanding the Marys Lake Substation was identified as the most effective way in which to improve electric service to Estes Park. The primary purpose and need of the proposed project is to improve the reliability of electric service to the Town of Estes Park. Lack of reliability has been a historical concern, and reliability will always be less than desired until physical improvements are made to the electrical facilities serving Estes Park.

  10. Marys Lake 69/115-kV transmission line upgrade and substation expansion projects

    International Nuclear Information System (INIS)

    1996-05-01

    Western Area Power Administration (Western) and the Platte River Power Authority (Platte River) propose to upgrade portions of the existing electric transmission and substation system that serves the Town of Estes Park, Colorado. The existing transmission lines between the Estes Power Plant Switchyard and the Marys Lake Substation include a 115,000 volt (115-kV) line and 69,000 volt (69-kV) line. Approximately one mile is a double-circuit 115/69-kV line on steel lattice structures, and approximately two miles consists of separate single-circuit 115-kV and a 69-kV lines, constructed on wood H-Frame structures. Both lines were constructed in 1951 by the US Bureau of Reclamation. The existing transmission lines are on rights-of-way (ROW) that vary from 75 feet to 120 feet and are owned by Western. There are 48 landowners adjacent to the existing ROW. All of the houses were built adjacent to the existing ROW after the transmission lines were constructed. Upgrading the existing 69-kV transmission line between the Marys Lake Substation and the Estes Power Plant Switchyard to 115-kV and expanding the Marys Lake Substation was identified as the most effective way in which to improve electric service to Estes Park. The primary purpose and need of the proposed project is to improve the reliability of electric service to the Town of Estes Park. Lack of reliability has been a historical concern, and reliability will always be less than desired until physical improvements are made to the electrical facilities serving Estes Park

  11. Procedure for the characterization of radon potential in existing dwellings and to assess the annual average indoor radon concentration

    International Nuclear Information System (INIS)

    Collignan, Bernard; Powaga, Emilie

    2014-01-01

    Risk assessment due to radon exposure indoors is based on annual average indoor radon activity concentration. To assess the radon exposure in a building, measurement is generally performed during at least two months during heating period in order to be representative of the annual average value. This is because radon presence indoors could be very variable during time. This measurement protocol is fairly reliable but may be a limiting in the radon risk management, particularly during a real estate transaction due to the duration of the measurement and the limitation of the measurement period. A previous field study defined a rapid methodology to characterize radon entry in dwellings. The objective of this study was at first, to test this methodology in various dwellings to assess its relevance with a daily test. At second, a ventilation model was used to assess numerically the air renewal of a building, the indoor air quality all along the year and the annual average indoor radon activity concentration, based on local meteorological conditions, some building characteristics and in-situ characterization of indoor pollutant emission laws. Experimental results obtained on thirteen individual dwellings showed that it is generally possible to obtain a representative characterization of radon entry into homes. It was also possible to refine the methodology defined in the previous study. In addition, numerical assessments of annual average indoor radon activity concentration showed generally a good agreement with measured values. These results are encouraging to allow a procedure with a short measurement time to be used to characterize long-term radon potential in dwellings. - Highlights: • Test of a daily procedure to characterize radon potential in dwellings. • Numerical assessment of the annual radon concentration. • Procedure applied on thirteen dwellings, characterization generally satisfactory. • Procedure useful to manage radon risk in dwellings, for real

  12. 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

  13. Radon - To mobilise civil society

    International Nuclear Information System (INIS)

    2016-01-01

    As radon is one of the two main sources of exposure of population to ionizing radiations in France, is notably said to be responsible of 1.000 to 3.000 deaths for lung cancer per year, and could be at the origin of other cancers like child leukaemia, this set of articles evokes the different factors which promote radon transfer from soils to buildings, studies performed to better identify geological sources of radon, actions implemented to assess radon presence in dwellings (distribution of 'radon kits' in Brittany), the performance of radiological expertise by the IRSN on the request of public authorities, the project of dwelling inventory and population information. A second article reports examples of intervention by the IRSN to inform local authorities, inhabitants, academics, public utilities, building professions, and even children. Technical solutions adopted in the United Kingdom are briefly evoked

  14. Radiation and Radon Survey of Akchatau (Khazakstan) and Experience with Radon Remedial Measures

    International Nuclear Information System (INIS)

    Soroka, Y.; Molchanov, A.

    1998-01-01

    A radiation survey of the territory of Akchatau settlement has been carried out. The main factors affecting the high content of radon in dwelling houses were revealed. The experiment on isolation of under floor spaces was carried out to prevent the entry of radon-containing soil gas into living rooms. The repair works efficiency for decreasing of the radon content in hazardous houses was analysed. The survey showed a need for regulation of the value of 222 Rn exhalation on the territories planned for construction works. (author)

  15. Radon and hydrotherapy: application to French spas

    International Nuclear Information System (INIS)

    Ameon, R.

    2004-01-01

    Owing to the use of thermal water for treatments, the dissolved radon ends up, through degassing, in the atmosphere of the various spa premises. According to the type of treatments, the radon activity concentration in the air is very variable; it depends on two factors, the supply of thermal water, and therefore of radon, and the ventilation of the various premises. In unfavourable, even non-existent, ventilation conditions, it is not uncommon to measure radon concentration reaching several thousands of becquerels per air cubic meter. These high values of radon activity concentration, with or without its short-lived daughters, may lead to a staff exposure of approximately ten or several tens of mSv per year. A French spa was subject to a radon 'expertise' during which the radon source terms, 'ground in contact with the buildings' and 'thermal water' were characterized. The radon mapping in the internal atmosphere of the various spa premises and the workstations' analysis resulted in an assessment of the exposure due to radon inhalation. This study showed that on workstations, notably linked to hydrotherapy, the staff exposure to radon is in the same range as the dose assessments from foreign studies. The implementation of an appropriate ventilation of the treatment rooms and a better management of the thermal water in the spa resulted in a significant reduction of staff exposure

  16. Third workshop on radon and radon daughters in urban communities associated with uranium mining and processing. Pt. 1

    International Nuclear Information System (INIS)

    1980-01-01

    This third meeting of Atomic Energy Control Board staff, contractors, federal and provincial government representatives, and delegates from outside Canada was held to discuss progress in reducing concentrations of radon and radon daughters in houses. Speakers talked about successful and unsuccessful remedial measures, methods of measuring and monitoring thoron and radon in houses, and indoor radon concentrations in Canada, Britain and Sweden

  17. Radon reduction in wood foundation system

    International Nuclear Information System (INIS)

    Clark, R.J.

    1990-01-01

    Radon, an issue of growing concern to the building industry. Silently, invisibly, it invades existing structures as it will future foundation structures. This paper addresses the nature and causes of radon, and cost-effective prevention and retrofit techniques used for wood foundation systems. Radon also can enter homes with foundations that use the under-floor as an air distribution system. These building practices will be shown; even materials used in construction may release radon, for example, this may be a problem in a house that has a solar heating system in which its heat is stored in large beds of stone. Stone is most often used in wood foundation construction. The common radon entry points will be looked at, and the latest prevention techniques will be illustrated, such as natural and forced ventilation, sealing major radon sources and entry routes, and sub-slab and sump crock ventilations

  18. Air pollution. Actions to promote radon testing

    International Nuclear Information System (INIS)

    Guerrero, Peter F.; Adams, Charles M.; McGee, William F.; Goldsmith, Larry A.; Feldesman, Alice G.; Grissinger, Charles R.; Updegraff, William D.; Langdon, Robin S.; Bartholomew, Philip L.

    1992-12-01

    To promote radon testing, EPA initiated public information and awareness programs and provided grants to states to develop programs aimed at encouraging homeowners to test for radon. Nationwide telephone surveys, according to EPA, indicate that these efforts have raised the public awareness of radon to as high as 78 percent but that about only 9 percent of those surveyed have tested their homes for radon. Concerned about improving risk reduction through its radon program, EPA convened a review panel. The panel not only recommended in May 1992 that the current voluntary approach be continued but also called for program changes to encourage more testing. These changes include targeting public information and other resources to areas where radon levels are predicted to be high and promoting testing and mitigation at the time of real estate transactions. To support state radon efforts, the Congress authorized a grant program for yearly grants of $10 million for 3 years. Funds for this program were recently extended for a fourth year through fiscal year 1993. Information to measure states' success in promoting testing by homeowners was generally not available because (1) much of the grant funding has been used to identify the extent of the radon problem; (2) federally funded public information projects were often directed to large audiences, making it difficult to measure testing rates; and (3) EPA's evaluation process for the grant program did not contain a component to measure increases in testing. We did, however, identify some state projects that have increased radon testing by targeting program efforts to homes in areas with potentially high levels of radon. The results of the state projects would seem to support the EPA review panel's recommendations on promoting radon testing through targeting program resources. In two states we surveyed, the voluntary use of disclosure statements as part of a real estate sales contract was a frequent occurrence, and in one state

  19. Radon in schools. An elevation measurement in schools in Baden-Wuerttemberg; Radon in Schulen. Eine Erhebungsmessung in Baden-Wuerttemberg

    Energy Technology Data Exchange (ETDEWEB)

    Fesenbeck, I.; Naber, C.; Frank, G.; Wilhelm, C.; Schaller, M. [Karlsruher Institut fuer Technologie (Germany). Sicherheit und Umwelt

    2016-07-01

    With an effective dose of about 1.1 mSv per year, radon and its secondary products have the biggest share in the population's natural radiation exposure. For implementation of the new EU directive 2013/59/EURATOM dated January 17, 2014, it is now planned to adapt the limit values of the Radiation Protection Ordinance and to extend the scope of validity in the EU member states. The ''Radon at Schools'' project is to cover an area-wide survey of radon concentrations in room air of schools in Baden-Wuerttemberg. Potential hazards caused by radon-222 and secondary products of radon are to be studied. For the project, 1600 schools were selected and requested to participate by an information letter. Half of the schools is distributed over the entire area of Baden-Wuerttemberg. The other half is located in areas of increased radon potential. Radon concentration in room air is determined passively by Karlsruhe radon exposimeters. Subsequently, active radon measurements will be made at conspicuous schools and information events will be offered for municipalities, teachers, interested parents, and pupils.

  20. Intercomparison of active, passive and continuous instruments for radon and radon progeny measurements in the EML chamber and test facility

    International Nuclear Information System (INIS)

    George, A.C.; Knutson, E.O.; Tu, K.W.; Fisenne, I.M.

    1995-12-01

    The results from the May 1995 Intercomparison of Active, Passive and Continuous Instruments for Radon and Radon Progeny Measurement conducted in the EML radon exposure and test facility are presented. Represented were 13 participants that measure radon with open faced and diffusion barrier activated carbon collectors, 10 with nuclear alpha track detectors, 9 with short-term and long-term electret/ionization chambers, and 13 with active and passive commercial electronic continuous monitors. For radon progeny, there were four participants that came in person to take part in the grab sampling methodology for measuring individual radon progeny and the potential alpha energy concentration (PAEC). There were 11 participants with continuous and integrating commercial electronic instruments that are used for measuring the PAEC. The results indicate that all the tested instruments that measure radon fulfill their intended purpose. All instruments and methods used for grab sampling for radon progeny did very well. However, most of the continuous and integrating electronic instruments used for measuring the PAEC or working level appear to underestimate the potential risk from radon progeny when the concentration of particles onto which the radon progeny are attached is -3