WorldWideScience

Sample records for atmospheric 222rn decay

  1. Factors controlling temporal variability of near-ground atmospheric 222Rn concentration over central Europe

    Science.gov (United States)

    Zimnoch, M.; Wach, P.; Chmura, L.; Gorczyca, Z.; Rozanski, K.; Godlowska, J.; Mazur, J.; Kozak, K.; Jeričević, A.

    2014-09-01

    Concentration of radon (222Rn) in the near-ground atmosphere has been measured quasi-continuously from January 2005 to December 2009 at two continental sites in Europe: Heidelberg (south-west Germany) and Krakow (southern Poland). The atmosphere was sampled at ca. 30 and 20 m above the local ground. Both stations were equipped with identical instruments. Regular observations of 222Rn were supplemented by measurements of surface fluxes of this gas in the Krakow urban area, using two different approaches. The measured concentrations of 222Rn varied at both sites in a wide range, from less than 2.0 Bq m-3 to approximately 40 Bq m-3 in Krakow and 35 Bq m-3 in Heidelberg. The mean 222Rn content in Krakow, when averaged over the entire observation period, was 30% higher than in Heidelberg (5.86 ± 0.09 and 4.50 ± 0.07 Bq m-3, respectively). Distinct seasonality of 222Rn signal is visible in the obtained time series of 222Rn concentration, with higher values recorded generally during late summer and autumn. The surface 222Rn fluxes measured in Krakow also revealed a distinct seasonality, with broad maximum observed during summer and early autumn and minimum during the winter. When averaged over a 5-year observation period, the night-time surface 222Rn flux was equal to 46.8 ± 2.4 Bq m-2 h-1. Although the atmospheric 222Rn levels at Heidelberg and Krakow appeared to be controlled primarily by local factors, it was possible to evaluate the "continental effect" in atmospheric 222Rn content between both sites, related to gradual build-up of 222Rn concentration in the air masses travelling between Heidelberg and Krakow. The mean value of this build-up was equal to 0.78 ± 0.12 Bq m-3. The measured minimum 222Rn concentrations at both sites and the difference between them was interpreted in the framework of a simple box model coupled with HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) analysis of air mass trajectories. The best fit of experimental data was

  2. Estimation of 222Rn flux and its effect on the atmospheric 222Rn concentration at Hachijo-jima Island, Japan

    International Nuclear Information System (INIS)

    Ohkura, Takehisa; Yamazawa, Hiromi; Moriizumi, Jun; Hirao, Shigekazu; Iida, Takao

    2010-01-01

    222 Rn fluxes from the ground surface and 226 Ra contents in soil were measured on Hachijo-jima Island, which is a solitary island in the Pacific Ocean located about 200 km to the south of the main island of Japan, to evaluate fractional contributions of the locally exhaled 222 Rn and the long-range transported one to the surface air concentration measured on this island. Averages of 222 Rn flux and 226 Ra content in dry soil were evaluated to be 0.9±0.4 mBq m -2 s -1 and 6.8±0.2 Bq kg -1 , respectively. These are considerably smaller than the respective values of 9.7±0.8 mBq m -2 s -1 and 23.2±0.4 Bq kg -1 measured at Nagoya as a reference. The lower value of the 226 Ra content and the even lower 222 Rn flux on this island can be attributed to the basaltic geology and the soil's coarse texture moisture, respectively. A simple model calculation assuming a typical nocturnal condition showed that the measured 222 Rn flux would cause only a small increase in the surface air concentration by 0.035 to 0.072 Bq m -3 (relative contribution of 1 to 12%) in addition to the long-range transported 222 Rn under a typical nocturnal condition. The contribution of the local flux would be smaller than that under nocturnal condition. This local 222 Rn component is negligible as compared with the concentration of the long-range transported 222 Rn (0.6 to 3.6 Bq m -3 ). It is, therefore, concluded that Hachijo-jima Island is suitable for measuring the long-range transported atmospheric 222 Rn in East Asia region. (author)

  3. Effective removal of airborne 222Rn decay products inside buildings

    International Nuclear Information System (INIS)

    Maher, E.F.; Rudnick, S.N.; Moeller, D.W.

    1987-01-01

    Comparisons were made of the effectiveness of various indoor air treatment methods in reducing the lung dose due to inhalation of 222 Rn decay products. The comparisons were based upon measurements of the total steady-state concentrations of 218 Po, 214 Pb and 214 Bi, and the concentrations of these nuclides not attached to particles. These measurements, which were made inside a 78-m3 room before and after air treatment, were used along with a state-of-the art lung dose model to predict reductions in the dose to the radiosensitive bronchial tissues. Results suggest that flow-through air-cleaning methods, such as filtration and electrostatic precipitation, although effective in reducing total potential alpha energy concentration, cause a greater quantity of airborne potential alpha energy to be unattached to particles. This may result in a substantial increase in the dose to bronchial tissues. The optimal form of air treatment appears to be a combination of nonuniform positive space charge generated by an ion generator and enhanced convection from a fan. This combination of air treatment gave reductions in the mean dose to the bronchial tissues of up to 87%

  4. Behaviour of 222Rn and its daughter products in open atmosphere

    International Nuclear Information System (INIS)

    Ondo-Estok, D.; Holy, K.; Stanys, T.; Polaskova, A.; Hola, O.

    2003-01-01

    In this contribution the influence of the meteorological conditions on activity concentrations of the outdoor 222 Rn and its daughter products is discussed in detail. In addition, the correlation between concentrations of measured radionuclides is studied and empirical relations for concentrations of radon daughter products are presented. he courses of the activity concentrations of 222 Rn and its short-lived decay products in the outdoor atmosphere are very similar even in some details. The average equilibrium factor F determined on the basis of our measurements in the outdoor atmosphere is approximately about 20 % lower than the value F recommended by UNSCEAR 1996 for the open air (F = 0,7). The obtained nonlinear relations between radon and its decay products reduce the applications of decay products in the atmospheric studies on one hand but on the other hand they can be useful at the calculation of the equilibrium equivalent radon concentration with the aim to determine the effective radon dose on the basis of the measurements of its activity concentrations only. (authors)

  5. 222Rn concentration in the outdoor atmosphere and its relation to the atmospheric stability

    International Nuclear Information System (INIS)

    Holy, K.; Boehm, R.; Bosa, I.; Polaskova, A.; Hola, O.

    1998-01-01

    The radon in the outdoor atmosphere has been monitored continuously since 1991. On the basis of the measured data mainly the average daily and the average annual courses of the 222 Rn concentrations have been studied. The annual courses of 222 Rn concentration are similar for all years. They present the annual variations. The average course of the 222 Rn concentration calculated on the basis of all continual measurements in the years 1991-1997 reaches the maximum value in October and the minimum value in April. The average daily courses of the 222 Rn concentration for the individual months of the year. The average daily courses have a form of waves with a maximum in the morning hours and with a minimum in the afternoon. The maximal amplitudes of daily waves have been reached in the summer months, from June till August. The amplitudes of daily waves are very small at the end of an autumn and during the winter months. The analysis of the daily waves and annual courses of 222 Rn showed that the amplitudes of the daily waves are in proportion to the global solar radiation irradiating the Earth's surface. The day duration influence on the phase of the daily wave and the wind velocity influence mainly on the level of the radon concentration. For the study of the relation of the radon concentration in the outdoor atmosphere to the stability the data of the atmosphere were obtained and they were correlated with the radon concentration. The results indicate that the 222 Rn concentrations int he outdoor atmosphere could be used for determination of the vertical atmospheric stability and these ones could reflect the atmospheric stability more completely than the different classifications based on the knowledge pertinent to the meteorological parameters. (authors)

  6. 222Rn and 14CO2 concentrations in the surface layer of the atmosphere

    International Nuclear Information System (INIS)

    Holy, K.; Chudy, M.; Sivo, A.; Richtarikova, M.; Boehm, R.; Polaskova, A.; Vojtyla, P.; Bosa, I.; Hola, O.

    2002-01-01

    Long-term monitoring of the Δ 14 C in the atmospheric near-ground CO 2 has been realized in Bratislava and Zlkovce, situated near the nuclear power plant Jaslovske Bohunice. Until 1993, the monthly mean Δ 14 C values showed a high variability. The annual means of Δ 14 C were about 30 per mille higher at Zlkovce than in highly industrialised Bratislava. An important change in the behaviour of the 14 C data has occurred since 1993. The records from both stations show the similar course, mainly due to the fact that there do not occur deep winter minima in Bratislava. This behaviour corresponds to the lower values of the total fossil fuel CO 2 emissions in the years after 1993 when compared to the previous years. At present, both sets of data show that the 14 C concentration is about 10% above the natural level. Since 1987 also the 222 Rn concentration in the surface layer of the atmosphere has been measured in Bratislava. These measurements provided an extensive set of the 222 Rn data characteristic for the inland environment with high level of atmospheric pollution. The seasonal and daily variations of the 222 Rn concentration were observed. The investigation of the relation between the monthly mean diurnal courses of the 222 Rn concentration and the atmospheric stability proved a high correlation between them. The 222 Rn data were used to interpret the anomalous Δ 14 C values in the surface layer of the atmosphere. (author)

  7. What we can learn from measurements of air electric conductivity in 222Rn-rich atmosphere

    Science.gov (United States)

    Seran, E.; Godefroy, M.; Pili, E.; Michielsen, N.; Bondiguel, S.

    2017-02-01

    Electric conductivity of air is an important characteristic of the electric properties of an atmosphere. Testing instruments to measure electric conductivity ranging from 10-13 to 10-9 S m-1 in natural conditions found in the Earth atmosphere is not an easy task. One possibility is to use stratospheric balloon flights; another (and a simpler one) is to look for terrestrial environments with significant radioactive decay. In this paper we present measurements carried out with different types of conductivity sensors in two 222Rn-rich environments, i.e., in the Roselend underground tunnel (French Alps) and in the Institute of Radioprotection and Nuclear Safety BACCARA (BAnC de CAllibrage du RAdon) chamber. The concept of the conductivity sensor is based on the classical time relaxation method. New elements in our design include isolation of the sensor sensitive part (electrode) from the external electric field and sensor miniaturization. This greatly extends the application domain of the sensor and permits to measure air electric conductivity when the external electric field is high and varies from few tens of V m-1 to up to few tens of kV m-1. This is suitable to propose the instrument for a planetary mission. Two-fold objectives were attained as the outcome of these tests and their analysis. First was directly related to the performances of the conductivity sensors and the efficiency of the conductivity sensor design to shield the external electric field. Second objective aimed at understanding the decay mechanisms of 222Rn and its progeny in atmosphere and the impact of the enclosed space on the efficiency of gas ionization.

  8. Estimation of groundwater flow rate using the decay of 222Rn in a well

    International Nuclear Information System (INIS)

    Hamada, Hiromasa

    1999-01-01

    A method of estimating groundwater flow rate using the decay of 222 Rn in a well was investigated. Field application revealed that infiltrated water (i.e., precipitation, pond water and irrigation water) accelerated groundwater flow. In addition, the depth at which groundwater was influenced by surface water was determined. The velocity of groundwater in a test well was estimated to be of the order of 10 -6 cm s -1 , based on the ratio of 222 Rn concentration in groundwater before and after it flowed into the well. This method is applicable for monitoring of groundwater flow rate where the velocity in a well is from 10 -5 to 10 -6 cm s -1

  9. Volume activity of 222Rn in the atmosphere of the nearby localities with the different orography

    International Nuclear Information System (INIS)

    Bulko, M.; Holy, K.; Polaskova, A.; Simon, J.; Hola, O.

    2006-01-01

    The monitoring of the volume activity of 222 Rn in the outdoor atmosphere was carried out in two areas - on the Faculty of Mathematics, Physics and Informatics, Comenius University (FMPI CU) and on the Slovak Metrological Institute (SMI) in Bratislava. The most significant differences were found out in the average daily courses of the 222 Rn volume activity for summer months, which show the different amplitudes and a relative displacement of a couple of hours. A possible reason for this can be that while on the FMPI CU there the solar radiation flux is not shielded by the terrain obstacles, the SMI measurement area is exposed to the solar radiation due to the shielding of the hills from the west only until 3 p.m. in summer and until 12 a.m. in winter. This produces the conditions for an earlier decrease of an intensity of the vertical exchange processes and therefore an earlier increase of the radon volume activity in 'SMI air', always in a couple of hours earlier than a similar observed increase in F MPI CU air . The daily course analysis also showed that the equivalent mixing height in the SMI area is about 30% lower than that one in the FMPI CU area. The analyses presented in this paper show that the daily courses of the 222 Rn volume activity can differ significantly even for two nearby areas with the different orography and that 222 Rn concentration is sensitive to these differences. It was also found out that if the long-term radon data should be collected in order to obtain the representative data for a larger area, an adequate attention should be paid to the selection of the measurement area. (authors)

  10. Results of long-term measurement of 222Rn concentrations in outdoor atmosphere

    International Nuclear Information System (INIS)

    Holy, K.; Boehm, R.; Polaskova, A.; Hola, O.

    1998-01-01

    Results are reported of the authors' long-term measurement of 222 Rn concentrations in the outdoor atmosphere. The measurements started in 1987 and were performed at a height of 1.5 m over a grass-covered ground surface, using till 1991 a Lucas type scintillation chamber and later a large volume scintillation chamber. Graphs are presented and discussed of the course of average monthly radon concentration in 1987-1996 and of annual courses of radon concentration for different time intervals of the day over 1991 to 1995. (A.K.)

  11. Surface deposition of 222Rn decay products with and without enhanced air motion

    International Nuclear Information System (INIS)

    Rudnick, S.N.; Maher, E.F.

    1986-01-01

    The effectiveness of fan-induced air motion in reducing airborne activities of short-lived 222 Rn decay products was evaluated in a 78.5-m3 chamber. Observed reductions were as high as 50% for 218Po (RaA), 79% for 214 Pb (RaB), and 86% for 214 Bi (RaC). Activity measurements of these nuclides on chamber and fan surfaces, along with airborne activities, were used to calculate material balances. Greater than about 90% of deposited activity was found on chamber surfaces, although areal activity densities were higher on fan surfaces. Deposition velocities for decay products not attached to particles were 2.3 mm s-1 when no fans were in operation and 9.2 to 13 mm s-1 when fans were used. Mean boundary layer thicknesses for unattached decay products were estimated to be about four times the recoil distance of a 214 Pb atom when no fans were used and about equal to the recoil distance when fans were used

  12. Short-term 222Rn activity concentration changes in underground spaces with limited air exchange with the atmosphere

    Science.gov (United States)

    Fijałkowska-Lichwa, L.; Przylibski, T. A.

    2011-04-01

    The authors investigated short-time changes in 222Rn activity concentration occurring yearly in two underground tourist facilities with limited air exchange with the atmosphere. One of them is Niedźwiedzia (Bear) Cave in Kletno, Poland - a natural space equipped with locks ensuring isolation from the atmosphere. The other site is Fluorite Adit in Kletno, a section of a disused uranium mine. This adit is equipped with a mechanical ventilation system, operated periodically outside the opening times (at night). Both sites are situated within the same metamorphic rock complex, at similar altitudes, about 2 km apart. The measurements conducted revealed spring and autumn occurrence of convective air movements. In Bear Cave, this process causes a reduction in 222Rn activity concentration in the daytime, i.e. when tourists, guides and other staff are present in the cave. From the point of view of radiation protection, this is the best situation. For the rest of the year, daily concentrations of 222Rn activity in the cave are very stable. In Fluorite Adit, on the other hand, significant variations in daily 222Rn activity concentrations are recorded almost all year round. These changes are determined by the periods of activity and inactivity of mechanical ventilation. Unfortunately this is inactive in the daytime, which results in the highest values of 222Rn activity concentration at the times when tourists and staff are present in the adit. Slightly lower concentrations of radon in Fluorite Adit are recorded in the winter season, when convective air movements carry a substantial amount of radon out into the atmosphere. The incorrect usage of mechanical ventilation in Fluorite Adit results in the most unfavourable conditions in terms of radiation protection. The staff working in that facility are exposed practically throughout the year to the highest 222Rn activity concentrations, both at work (in the adit) and at home (outside their working hours). Therefore, not very well

  13. Relation between 222Rn concentration in outdoor air and lower atmosphere

    International Nuclear Information System (INIS)

    Kataoka, Toshio; Mori, Tadashige; Yunoki, Eiji; Michihiro, Kenshuh; Sugiyama, Hirokazu; Shimizu, Mitsuo; Tsukamoto, Osamu; Sahashi, Ken.

    1991-01-01

    Using the height of the surface-based inversion layer obtained by the acoustic sounder returns and the variation of the 222 Rn concentration in the outdoor air during the presence of the surface-based inversion layer, the exhalation rate of 222 Rn is estimated to be 0.020 Bq·m -2 ·s -1 , which is observed elsewhere on land. Furthermore, the exposure rate at 1 m above the air-ground interface due to the short-lived 222 Rn daughters in the outdoor air during the presence of the surface-based inversion layer can be estimated using the height of the surface-based inversion layer and the 222 Rn concentrations in the outdoor air at the ground level before and after the onset of the surface-based inversion layer. From these treatment, it is clearly demonstrated that the monostatic acoustic sounder is useful as a supplementary method for a weather survey which forms a part of monitoring around the nuclear facilities. (author)

  14. An international marine-atmospheric 222Rn measurement intercomparison in Bermuda. Part 2: Results for the participating laboratories

    International Nuclear Information System (INIS)

    Colle, R.; Unterweger, M.P.; Hutchinson, J.M.R.

    1996-01-01

    As part of an international measurement intercomparison of instruments used to measure atmospheric 222 Rn, four participating laboratories made nearly simultaneous measurements of 222 Rn activity concentration in commonly sampled, ambient air over approximately a 2 week period, and three of these four laboratories participated in the measurement comparison of 14 introduced samples with known, but undisclosed (blind) 222 Rn activity concentration. The exercise was conducted in Bermuda in October 1991. The 222 Rn activity concentrations in ambient Bermudian air over the course of the intercomparison ranged from a few hundredths of a Bq · m -3 to about 2 Bq · m -3 , while the standardized sample additions covered a range from approximately 2.5 Bq · m -3 to 35 Bq · m -3 . The overall uncertainty in the latter concentrations was in the general range of 10%, approximating a 3 standard deviation uncertainty interval. The results of the intercomparison indicated that two of the laboratories were within very good agreement with the standard additions, and almost within expected statistical variations. These same two laboratories, however, at lower ambient concentrations, exhibited a systematic difference with an averaged offset of roughly 0.3 Bq · m -3 . The third laboratory participating in the measurement of standardized sample additions was systematically low by about 65% to 70%, with respect to the standard addition which was also confirmed in their ambient air concentration measurements. The fourth laboratory, participating in only the ambient measurement part of the intercomparison, was also systematically low by at least 40% with respect to the first two laboratories

  15. High-resolution ion pulse ionization chamber with air filling for the {sup 222}Rn decays detection

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilyuk, Yu.M.; Gangapshev, A.M.; Gezhaev, A.M.; Etezov, R.A.; Kazalov, V.V.; Kuzminov, V.V. [Baksan Neutrino Observatory,Institute for Nuclear Research RAS, 361609 Neutrino (Russian Federation); Panasenko, S.I. [V.N.Karazin Kharkiv National University, 61022 Kharkiv (Ukraine); Ratkevich, S.S., E-mail: ssratk@gmail.com [V.N.Karazin Kharkiv National University, 61022 Kharkiv (Ukraine); Tekueva, D.A.; Yakimenko, S.P. [Baksan Neutrino Observatory,Institute for Nuclear Research RAS, 361609 Neutrino (Russian Federation)

    2015-11-21

    The construction and characteristics of the cylindrical ion pulse ionization chamber (CIPIC) with a working volume of 3.2 L are described. The chamber is intended to register α-particles from the {sup 222}Rn and its daughter's decays in the filled air sample. The detector is less sensitive to electromagnetic pick-ups and mechanical noises. The digital pulse processing method is proposed to improve the energy resolution of the ion pulse ionization chamber. An energy resolution of 1.6% has been achieved for the 5.49 MeV α-line. The dependence of the energy resolution on high voltage and working media pressure has been investigated and the results are presented. - Highlights: • The construction and characteristics of the cylindrical ion pulse ionization chamber (CIPIC) with a working volume of 3.2 L are described. • The chamber is intended to register alpha-particles from {sup 222}Rn and its daughter's decays in the filled air sample. • The detector is less sensitive to electromagnetic pick-ups and mechanical noises. • An energy resolution of 1.6% has been achieved for the 5.49 MeV alpha-line. The dependence of the energy resolution on high voltage and working media pressure have been investigated and the results are presented.

  16. Local variations of atmospheric 222Rn and 210Pb concentrations in Badgastein (Austria)

    International Nuclear Information System (INIS)

    Wallner, G.; Ayromlou, S.

    2002-01-01

    222 Rn was measured and aerosols for 210 Pb determination were collected simultaneously outdoors at ground level near the train station of Badgastein (1080 m a.s.l.), and later on also on the nearby Stubnerkogel (2230 m a.s.l.). Radon concentrations at lower altitude were up to 140 Bq/m 3 , on the mountain the usual background levels were found. In contrary to the differing radon levels, the 210 Pb activity concentrations were in the same order of magnitude for both locations with values between 0.16 and 0.77 mBq/m 3 . (author)

  17. Measurement of 222Rn, 220Rn and their decay products in high background radiation area in Yangjiang

    International Nuclear Information System (INIS)

    Yuan Yongling

    2000-01-01

    The investigators have measured concentrations of Rn-222, rn-220 and their decay products in high background radiation area (HBRA) and the neighboring control area (CA), as well as the equilibrium factor F for Rn-222. The average concentrations of Rn-222 in the air indoors and outdoors in the HBRA are 42.6 and 17.3 Bq/m 3 respectively, and CA, 13.2 and 11.7 Bq/m 3 , respectively. The average α-potential energy concentrations for daughters of Rn-222 indoors and outdoors in HBRA are 0.109 and 0.051 μJ/m 3 , CA, 0.045 and 0.041 μJ/m 3 , respectively. The average α-potential energy values for daughters of Rn-220 indoor and outdoor in HBRA are 0.249 and 0.053 μJ/m 3 , CA, 0.051 and 0.025 μJ/m 3 , respectively. With regard to equilibrium factor F for Rn-222, the authors have also measured 52 points of 10 hamlets in HBRA (indoor 31, outdoor 21), 9 points of 2 hamlets in CA (indoor 5, outdoor 4), respectively. These figures are 0.46, 0.53, 0.62 and 0.64, respectively

  18. The use of long-lived 222Rn decay products (LRnD) as natural tracers in the indoor environment

    International Nuclear Information System (INIS)

    Samuelsson, C.

    1998-01-01

    In the radioactive decay chain following 222 Rn (radon) the first long-lived product 210 Pb (t 1/2 = 22.3 y) acts like a stopper and its decay products can be utilized as integrators of passed radon gas levels and a tracer reflecting long-term aerosol particle deposition processes. Long-term integration is feasible only if the LRnD activity is hidden away from the destructive practices of everyday life, such as cleaning and refurbishing. Three type of LRnD hide away places (traps) can be identified: i) Inside the human body, ii) Inside porous volumes, and iii) In surface implants. The volume trap (ii) is advantageous as it is a pure radon gas detector and as such not influenced by the indoor aerosol conditions. The drawbacks are that suitable samples is difficult to find and that tedious radio chemistry is mandatory. Alpha-recoil implanted LRnD activity (iii) into hard surfaces is the only type of trap that is suitable for large-scale retrospective measurements and the main emphasis of this contribution will be on implanted activity. Fortunately, cheap in-situ track-etch methods are now available for specific detection of implanted 210 Po into flat glass surfaces. In the ongoing Swedish non-smoker radon study only samples older than 20 years are accepted and a tentative calibration factor of 0.84 Bq.m -2 of implanted 210 Po per kBq.y.m -3 radon gas exposure is used. The aim of this contribution is to draw attention to a fairly recent field of application in the radon indoor environment, where long-lived radon daughter are used to indicate past radon concentration levels

  19. Skeletal sup 210 Pb from inhalation of sup 222 Rn and its decay products

    Energy Technology Data Exchange (ETDEWEB)

    Keane, A.T.; Schlenker, R.A.; Stebbings, J.H.

    1990-01-01

    Concern about health effects of radon and its decay products has recently broadened to include the potential role of radon in the causation of myeloid leukemia, multiple myeloma, and melanoma, kidney cancer, and certain childhood cancers. Description of the distribution of radon and its daughters in the skeleton and the marrow, and the dose delivered to red marrow, are of particular relevance. Our interest in a metabolic model for inhaled radon and radon decay products originated with an interest in the use of radioactivity measurement techniques in vivo to quantify the {sup 210}Pb activity of bone. In this paper we estimate the rates of transfer to body fluids of {sup 210}Pb originating from inhaled radon and radon decay products and the quantity of {sup 210}Pb deposited in compact and in cancellous bone for the ideal case of continuous exposure to a constant level of radon and its daughters. We review the contributions of ambient airborne {sup 210}Pb, diet, and active and passive smoking to skeletal levels of {sup 210}Pb, and finally, from the magnitude and the variability of the natural {sup 210}Pb content of the skeleton, we estimate the minimal rate of exposure to airborne radon and its decay products that is required to elevate the skeletal {sup 210}Pb content of an individual to a statistically significant level above the population mean skeletal {sup 210}Pb content derived from all the other environmental sources combined. 55 refs., 4 tabs.

  20. Observation of atmospheric 210Pb and 212Pb originating from the 2004 eruptive activity of Asama volcano, Japan, and relevant 222Rn releasing from the erupting magma

    International Nuclear Information System (INIS)

    Kukita, Kazuhiko; Koike, Yuya; Nakamura, Toshihiro; Sato, Jun; Saito, Takashi

    2005-01-01

    This paper describes a study of observation of atmospheric 210Pb and 212Pb possibly from the volcano (36 deg N, 138 deg E) activity in the title and of measurement of 222Rn releasing efficiency with the ash-fall deposit collected around the period. The aerosol sample was collected from Sep. 1, an eruption day, on a building terrace (10 m high) of Meiji University at Kawasaki, located at 140 km SE of the volcano, every 24 hr on the glass fiber filter using a high volume air sampler. The filter was cut out to 4 disks, which were packed into acrylic canisters with a window of a thin Mylar film for non-destructive γ-ray measurement. 210Pb and 212Pb radioactivities were determined by the 46.5- and 238.6-keV γ-rays with an LEPS (low energy photon spectrometer) and an HPGe spectrometer, respectively. The ash-fall sample from the eruption Sep. 14, was collected at Kanrakumachi, Gunma Pref., 40 km SE of the volcano, and measurement for the growth curve of 222Rn from the fall started 1 week after the eruption. A well-type HPGe spectrometer was used for determination of the 351.9-keV γ-ray of 222Rn from 214Pb in equilibrium, which was normalized by the 911.1-keV 228Ac γ-ray. 210Pb and 212Pb emitted into the atmosphere were suggested to have been transported 140 km within the time of a few times of the 212Pb half life (10.6 hr) on the northerly wind. 210Pb and 212Pb, and 222Rn were suggested to be a possibly useful tool of monitoring magmatic activities. (S.I.)

  1. Annual effective dose equivalents arising from inhalation of 222Rn, 220Rn and their decay products in high background radiation area in China

    International Nuclear Information System (INIS)

    Zhang Zhonghou

    1985-01-01

    The author presents the data of on-the-sport investigations in the high background radiation area in Yangjiang County in 1975 and 1981. Monazite sand is contained in the soil of this area. The average concentrations of 222 Rn in the air indoors and out doors of the high background radiation area are 31.8 and 16.4 Bqm -3 respectively, which are equal to 2.9 and 1.5 times the average concentrations in the control area. The average concentrations of 220 Rn in the air indoors and outdoors of the high background area are 167.5 and 18.4 Bqm -3 , corresponding to 9.6 and 4.8 times those of the control area respectively. The average potential alpha energy concentrations for daughters of 222 Rn indoors and outdoors are 0.1 and 0.097 μJm -3 , which are equal to 2.6 and 2.2 times those of the control are respectively. The average potential alpha energy concentrations for daughters of 220 Rn indoors and outdoors are 0.255 and 0.053 μJm -3 , corresponding to 3.7 and 2.7 times those of the control area respectively. The average annual effective dose equivalents arising from inhalation of 222 Rn, 220 Rn and their decay products in high background radiation area are estimated to be 2.8 mSv per caput, in which 40.5% arise from 220 Rn and its decay products. This result is about 3 times that in the neighboring control area

  2. Study of the daily and seasonal atmospheric CH4 mixing ratio variability in a rural Spanish region using 222Rn tracer

    Science.gov (United States)

    Grossi, Claudia; Vogel, Felix R.; Curcoll, Roger; Àgueda, Alba; Vargas, Arturo; Rodó, Xavier; Morguí, Josep-Anton

    2018-04-01

    The ClimaDat station at Gredos (GIC3) has been continuously measuring atmospheric (dry air) mixing ratios of carbon dioxide (CO2) and methane (CH4), as well as meteorological parameters, since November 2012. In this study we investigate the atmospheric variability of CH4 mixing ratios between 2013 and 2015 at GIC3 with the help of co-located observations of 222Rn concentrations, modelled 222Rn fluxes and modelled planetary boundary layer heights (PBLHs). Both daily and seasonal changes in atmospheric CH4 can be better understood with the help of atmospheric concentrations of 222Rn (and the corresponding fluxes). On a daily timescale, the variation in the PBLH is the main driver for 222Rn and CH4 variability while, on monthly timescales, their atmospheric variability seems to depend on emission changes. To understand (changing) CH4 emissions, nocturnal fluxes of CH4 were estimated using two methods: the radon tracer method (RTM) and a method based on the EDGARv4.2 bottom-up emission inventory, both using FLEXPARTv9.0.2 footprints. The mean value of RTM-based methane fluxes (FR_CH4) is 0.11 mg CH4 m-2 h-1 with a standard deviation of 0.09 or 0.29 mg CH4 m-2 h-1 with a standard deviation of 0.23 mg CH4 m-2 h-1 when using a rescaled 222Rn map (FR_CH4_rescale). For our observational period, the mean value of methane fluxes based on the bottom-up inventory (FE_CH4) is 0.33 mg CH4 m-2 h-1 with a standard deviation of 0.08 mg CH4 m-2 h-1. Monthly CH4 fluxes based on RTM (both FR_CH4 and FR_CH4_rescale) show a seasonality which is not observed for monthly FE_CH4 fluxes. During January-May, RTM-based CH4 fluxes present mean values 25 % lower than during June-December. This seasonal increase in methane fluxes calculated by RTM for the GIC3 area appears to coincide with the arrival of transhumant livestock at GIC3 in the second half of the year.

  3. 222Rn in wine cellars in Hungary

    International Nuclear Information System (INIS)

    Csige, I.; Hunyadi, I.; Szerbin, P.; Juhasz, L.

    2004-01-01

    We measured seasonal average 222 Rn activity concentrations in the air of 60 wine cellars in the Tokajhegyalja and Villany wine regions of Hungary using Radamon type etched track radon detectors. The exposure period was 3 months, matching the seasons of 2003-2004. We also used an ionization chamber-type continuous 222 Rn-monitor (AlphaGUARD PQ222, Genitron Instruments, Germany) to study temporal variations of 222 Rn activity concentration in a selected wine cellar in the Tokajhegyalja wine region. This instruments also recorded temperature, atmospheric pressure and relative humidity data. The etched track detector data revealed that the 222 Rn activity concentrations in the air of wine cellars spread over a wide range, from the ambient outdoor concentration of 6 Bq.m -3 up to 6 kBq.m -3 characteristic of natural caves. The temporal variation of 222 Rn activity concentration in the air of the selected cellar varied inversely with the variation of the atmospheric pressure. Earlier we observed similar phenomena in natural karstic caves connected to the surface with vertical shafts only. This suggests that relatively large volume of pore space of the embedding rock communicates with the volume of the cellar induced by the variation of the atmospheric pressure

  4. Ten years of continual monitoring of 222Rn concentration in Bratislava atmosphere

    International Nuclear Information System (INIS)

    Holy, K.; Bosa, I.; Polaskova, A.; Boehm, R.; Ondo-Estok, D.; Bulko, M.; Hola, O.

    2003-01-01

    By the continual monitoring we obtained the extensive set of radon data in Bratislava atmosphere covering the time period of 1991 - 2000. The average annual radon activity concentrations varied from 4.1 to 7.2 Bq/m 3 . In the years 1996 - 1999 the decreasing of the average annual radon concentration was observed. The average daily courses of the radon activity concentration for individual months calculated on the basis of all data from 1991 - 2000 have a form of waves with the maximum in morning hours and with the minimum in the afternoon. The maximal amplitude of daily wave was found out in August (2.9 Bq/m 3 ) and minimal in December (0.5 Bq/m 3 ). The average daily wave obtained as the mean off all data from years 1991 - 2000 reaches the maximum between 4 and 6 a. m. and the minimum between 2 and 4 p. m. The Rn-222 activity concentration reaches its average daily value equal to 5.6 Bq/m 3 at about 10 a. m and at 9 p. m. The amplitude of average daily wave is equal to 1.5 Bq/m 3 . The average annual radon course calculated on the basis of all the measured data reaches the minimum in April and the maximum in October with seasonal variation from 3.9 to 6.9 Bq/m 3 . The annual radon courses differ from each other for various periods of the day. (authors)

  5. 222Rn flux and soil air concentration profiles in West-Germany. Soil 222Rn as tracer for gas transport in the unsaturated soil zone

    International Nuclear Information System (INIS)

    Doerr, H.; Muennich, K.O.

    1990-01-01

    Measurements of the 222 Rn activity concentration profile in the soil and the 222 Rn flux in West-Germany are presented. The spatial pattern of the 222 Rn flux depends more on soil type than on the 226 Ra activity of the soil material. The average 222 Rn flux from sandy soils is 1000-2000 dpm m -2 h -1 and 4000-6000 dpm m -2 h -1 froam loamy and clayey soils. Weekly 222 Rn flux measurements during a period of 1 year at a sandy site show no significant temporal variations. At a clayey site, the 222 Rn flux tends to be higher in summer than in winter. The permeability coefficient P Rn , obtained from simultaneous 222 Rn flux and concentration profile measurements in various soils, can be expressed as a function of the soil parameters total porosity ε 0 , soil moisture F, tortuosity k and the molecular diffusion coefficient D 0 of 222 Rn in air: P = D 0 ((ε 0 -F)/k-const.). The flux of any other gas into or out of the soil can thus be calculated from its measured concentration profile in the soil and from the 222 Rn permeability coefficient, replacing the molecular diffusion coefficient of 222 Rn by that of the specific gas under consideration. As an example, this method of flux determination is demonstrated for the soil CO 2 flux to the atmosphere and for the flux of atmospheric CH 4 into the soil. (author) 14 refs

  6. Inferring 222Rn soil fluxes from ambient 222Rn activity and eddy covariance measurements of CO2

    Directory of Open Access Journals (Sweden)

    S. van der Laan

    2016-11-01

    calibration of process-based 222Rn soil flux models, validation of atmospheric transport models and performing regional-scale inversions, e.g. of greenhouse gases via the SPOT 222Rn-tracer method.

  7. 222Rn alpha dose to organs other than lung

    International Nuclear Information System (INIS)

    Harley, N.H.; Robbins, E.S.

    1991-01-01

    The alpha dose to cells in tissues or organs other theft the lung has been calculated using the solubility coefficients for 222 Rn measured in human tissue. The annual alpha dose equivalent f rom 222 Rn and decay products in most tissues is a maximum of 30% of the annual average natural background dose equivalent (1 mSv) for external and internally deposited nuclides. The dose to the small population of lymphocytes located in or under the bronchial epithelium is a special case and their annual dose equivalent is essentially the same as that to basal cells in bronchial epithelium (200 mSv) for continuous exposure to 200 Bq M -3 . The significance of this dose is uncertain because the only excess cancer observed in follow up studies of underground miners with high 222 Rn exposure is bronchogenic carcinoma

  8. Study of 222Rn variations in the soil air

    International Nuclear Information System (INIS)

    Holy, K.; Boehm, R.; Matos, M.; Polaskova, A.; Hola, O.

    1998-01-01

    A significant source of radon in the indoor atmosphere is represented by 222 Rn in the soil air, ie., by the fraction of radon atoms produced by alpha decay of 226 Ra in soil grains that escaped into soil pores. In the paper the results are presented of a three year monitoring of radon in soil air, using a 125 ml Lucas type scintillation cell. Radon concentration depth profiles in the soil in various seasons of the year were also measured, and saturated concentration of radon in soil air was found at a depth of about 2 m. Monthly variations in the radon concentration were observed over several months and the possible causes of the variations are discussed. Daily courses of radon concentration were also measured and the results are presented. (A.K.)

  9. Average daily and annual courses of 222Rn concentration in some natural medium

    International Nuclear Information System (INIS)

    Holy, K.; Bohm, R.; Polaskova, A.; Stelina, J.; Sykora, I.; Hola, O.

    1996-01-01

    Simultaneous measurements of the 222 Rn concentration in the outdoor atmosphere of Bratislava and in the soil air over one year period have been made. Daily and seasonal variations of the 222 Rn concentration in both media were found. Some attributes of these variations as well as methods of measurements are presented in this work. (author). 17 refs., 6 figs

  10. Estimating the mean and variance of measurements from serial radioactive decay schemes with emphasis on 222Rn and its short-lived progeny

    International Nuclear Information System (INIS)

    Inkret, W.C.; Borak, T.B.; Boes, D.C.

    1990-01-01

    Classically, the mean and variance of radioactivity measurements are estimated from poisson distributions. However, the random distribution of observed events is not poisson when the half-life is short compared with the interval of observation or when more than one event can be associated with a single initial atom. Procedures were developed to estimate the mean and variance of single measurements of serial radioactive processes. Results revealed that observations from the three consecutive alpha emissions beginning with 222 Rn are positively correlated. Since the poisson estimator ignores covariance terms, it underestimates the true variance of the measurement. The reverse is true for mixtures of radon daughters only. (author)

  11. Use of 222Rn for estimation of greenhouse gases emissions at Russian territory

    Science.gov (United States)

    Berezina, E. V.; Elansky, N. F.

    2009-04-01

    It is well known that 222Rn is widely used as a tracer for studying different atmospheric processes including estimations of greenhouse gases emissions. Calculation of 222Rn fluxes from the soil into the atmosphere allows quantitative estimation of greenhouse gases emissions having the soil origin or sources of which are located near the surface. For accurate estimation of 222Rn fluxes detailed investigations of spatial and temporal variations of its concentrations are necessary. 222Rn concentrations data in the atmospheric surface layer over continental Russia from Moscow to Vladivostok obtained during the six TROICA (Transcontinental Observations Into the Chemistry of the Atmosphere) expeditions of the mobile laboratory along the Trans-Siberian railroad are analyzed. Spatial distribution, diurnal and seasonal variations of surface 222Rn concentrations along the Trans-Siberian railroad are investigated. According to the obtained data surface 222Rn concentration values above continental Russia vary from 0.5 to 75 Bq/m3 depending on meteorological conditions and geological features of the territory with the average value being 8.42 ± 0.10 Bq/m3. The average 222Rn concentration is maximum in the autumn expedition and minimum in the spring one. The factors mostly influencing 222Rn concentration variations are studied: surface temperature inversions, geological features of the territory, precipitations. 222Rn accumulation features in the atmospheric surface layer during night temperature inversions are analyzed. It was noted that during night temperature inversions the surface 222Rn concentration is 7 - 8 times more than the one during the nights without temperature inversions. Since atmospheric stratification determines accumulation and diurnal variations of many atmospheric pollutants as well as greenhouse gases its features are analyzed in detail. Surface temperature inversions were mainly observed from 18:00-19:00 to 06:00-07:00 in the warm season and from 16

  12. Some remarks on exact methods for WL and 222Rn-daughter determination

    International Nuclear Information System (INIS)

    Groer, P.G.

    1977-01-01

    For an exact determination of the three 222 Rn-daughter concentrations (RaA, B and C) which properly weighted yield the Working Level, three equations relating observed counts (α or β) to these unknown concentrations have to be solved. The half-lives in the 222 Rn decay series, the type of decay and the counting errors, limit the suitable set of equations. Some aspects of two such exact methods are discussed

  13. Assessing urban air quality and its relation with radon (222Rn)

    International Nuclear Information System (INIS)

    Zoran, Maria; Savastru, Dan; Dida, Adrian

    2016-01-01

    This paper focuses on the assessment of air quality and its relation with radon ( 222 Rn) for Bucharest metropolitan area in Romania. Specifically, daily mean concentrations of particle matter (PM2.5, PM10), ozone (O 3 ), nitrogen dioxide (NO 2 ), sulphur dioxide (SO 2 ) and global air quality indices have been analyzed in relation with radon ( 222 Rn) concentrations measured in the air near the ground with AlphaGUARD Radon Monitoring System and CR-39 SSNTDs during 2012 year. Such new information is required by atmospheric sciences to prove suitability of 222 Rn as a tracer for atmospheric dynamics analysis as well as by epidemiological and radiological protection studies. (author)

  14. Theoretical study of the diffusion 222Rn gas on activated charcoal

    International Nuclear Information System (INIS)

    Lopez, Fabio O.; Canoba, Analia C.

    2001-01-01

    The 222 Rn adsorption coefficient is the fundamental parameter characterizing activated carbon's ability to adsorb 222 Rn . In this work, it has been determined the 222 Rn coefficient adsorption for 222 Rn activated carbon detectors. Scintillation vials were used as detectors. The measurement of the 222 Rn activity adsorbed in activated carbon was made by a liquid scintillation measurement of its alpha-beta progeny decay. On the other hand, in this work a diffusion and adsorption model has been developed for the transport of 222 Rn in an activated carbon porous bed. The equation that describes these processes is a partial differential equation, of the second order with respect to axial coordinate, and the first order with respect to time. The equation was numerically solved using a finites differences method. With this model the 222 Rn activity adsorbed in the detector, for several situations, was calculated. The results were tested with the data obtained from series of experiences made in our laboratories. (author)

  15. Microdosimetry of haemopoietic stem cells irradiated by α particles from the short-lived products of 222Rn decays in fat cells and haemopoietic tissue

    International Nuclear Information System (INIS)

    Charlton, D.E.; Utteridge, T.D.; University of South Australia, Pooraka, SA; Beddoe, A.H.

    1996-01-01

    The Monte Carlo method is used to model fat cells and the nuclei of stem cells in haemopoietic tissue where 222 Rn is dissolved in different amounts in the fat and tissue. Calculations are performed for fat cells of diameters 50 and 100 μm and for stem cell nuclei of 8 and 16 μm diameters for various fractions of fat filling the volume. Average doses (and their distributions) to stem cell nuclei from single passages of α particles are presented. In addition to dose, the relationship between LET and dose is obtained, illustrating the importance of 'stoppers' in the calculations. The annual average dose equivalent for a concentration of 1 Bq/m 3 in air agrees well with other authors at 12 μSv/year. The method also allows the calculation of the fraction of stem cell nuclei hit annually. Here for 1 Bq/m 3 , stem cell nuclei of diameter 8 μm and 100% fat filing 15 x 10 -7 of the stem cell nuclei are hit. (Author)

  16. Vibrations in the urban environment controlling 222Rn migration in soils

    International Nuclear Information System (INIS)

    Wiegand, J.

    1998-01-01

    Comparable to investigations looking for a connection of 222 Rn and earthquakes, this study shows the influence of subsurface vibrations on the 222 Rn concentration of the soil-gas in urban environments. Generally, the 222 Rn concentration increases through vibrations induced by trains, street-traffic and activities at project sites. The spatial radius of the 222 Rn increase due to vibrations reach highest values at project sites where piled foundations or metal panels are rammed into the ground (> 60 m). Along railway tracks the radius is wider (> 30 m) than along heavy traffic roads ( 222 Rn concentrations in soil-gas due to vibrations is the highest at project sites (53%). Along heavy traffic roads the increase of 222 Rn concentrations by motor vehicle traffic is higher (37%) than that by railway traffic (11.5%). The maximum increase of 400% was observed in a distance of 1 m from a railway track. In the vicinity of railway tracks a difference of the vibration influence according to unconsolidated rock (11.1%) or solid rock (11.8%) was not noticed. Beside this vibration effect, the overall 222 Rn level decreases with increasing distance to the vibration source, but only at locations laying above solid rocks. The observation of the increase of 222 Rn concentrations can be explained by a 'pump effect': the mechanical vibration of soil and mineral particles leads to an upward motion of the whole volume of soil-gas. Therefore, 222 Rn is pumped out of the soil to the atmosphere and as a result the upward transport is increased. (author)

  17. Estimate of 50-year dose commitment to various organs and tissues of the body from inhalation of 222Rn free of its daughters

    International Nuclear Information System (INIS)

    Bernard, S.R.; Ford, M.R.; Snyder, W.S.

    1976-01-01

    Some topics discussed are as follows: retention of 222 Rn in fat, bone, heart, muscle, skin, testes, and urinary bladder; retention equations for Rn; decay scheme for Rn and 226 Ra; metabolic models for Po, Pb, and Bi; dose estimates to target organs for 222 Rn and its daughters that are not inhaled but produced from decay of 222 Rn; and estimation of MPC for bone marrow, gonads, and total body

  18. Results of Long-term Measurement of 222Rn Volume Activity in Soil Air

    International Nuclear Information System (INIS)

    Holy, K.; Matos, M.; Boem, R.; Stanys, T.; Hola, O.; Polaskova, A.

    1999-01-01

    Radon in the soil air was continuously monitored for four years. The measured volume activities differ one from another even three times. On the basis of the measured data the annual and average daily courses of the 222 Rn volume activity were studied for individual months. In annual courses the winter and also summer maxima of the 222 Rn volume activity were found out. The study of the average daily courses revealed that the oscillation of the 222 Rn volume activity about its average value during a day is only a few percent. For dry summer months a linear relation was found out between the changes of the 222 Rn volume activity and the changes of the atmospheric pressure in their average daily courses (Authors)

  19. Standards, calibration and quality assurance of 222Rn measurements in Sweden

    International Nuclear Information System (INIS)

    Falk, R.; Hagberg, N.; Mjoenes, L.; Moere, H.; Nyblom, L.; Swedjemark, G.A.

    1994-01-01

    Inhaled decay products of 222 Rn are the dominant components of the natural radiation exposure to the general population. Limits have been introduced in Sweden, and recommendations were made in 1980 for decreasing indoor 222 Rn concentration. The need for the coordinated calibration of measuring instruments as well as for quality assurance was obvious for both health and economic reasons. 222 Rn measurements in Sweden are based on standards traceable to the National Institute of Standard and Technology (NIST) through the use of standard reference material 226 Ra. Standards for both 222 Rn and short-lived 222 Rn progeny are described together with the reference instrument adopted for these studies. The calibration of field instruments was performed in a ''radon room'', a climate chamber in which it is possible to vary and monitor the concentration of 222 Rn as well as other characteristics of the indoor air such as temperature, humidity, ventilation rate and aerosol concentration. The rules and regulations for field measurements imply a calibration of the instruments yearly, as well as accreditation and training for the companies that carry out the measurements. Examples are given of the official measurement protocols used for the different types of instruments. (orig.)

  20. Detection of 222Rn and 226Ra in environmental samples by scintillation method

    International Nuclear Information System (INIS)

    Zafimanjato, J.L.R.; Raoelina Andriambololona; Mobius, S.

    2009-01-01

    222 Rn is considered as the major source of radiological exposure of natural radiations to the population. It represents about the half of exposures of natural radiation sources in the world (UNSCEAR, 1993). 222 Rn gets into human body with inhaled air and sometimes with drinking water. Then, the objective of this work is to know the 222 Rn concentrations in water and in indoor atmosphere, and the risk in order to set up a method of monitoring and to identify high radon level areas. A specific method of detection using liquid scintillation with special emphasis on α/β discrimination, the use of solvent extractive and enrichment of radionuclides have been developed for the determination of both 222 Rn and 226 Ra in water. The method is simple, rapid and sensitive. It was shown that the proposed method was suitable for a large scale monitoring and routine analysis. Considerable concentrations of 222 Rn were found in water and air samples from Vinaninkarena - Antsirabe. 222 Rn concentrations obtained by in situ and in laboratory measurements have been compared to the results of an international intercomparison campaigns organised by the German Society for Liquid Scintillation Spectrometry in 2001. An assesment model of the dose due to ingestion and liberation of radon from water is presented and compared with other models especially to the Crawford Brown's model.

  1. Evaluation of local versus remote areas of CH4 sources at IC3 stations using a combined analysis of 222Rn tracer and Atmospheric Particles Transport Model (APTM) results. Application at the Gredos and Iruelas station (GIC3), Spain.

    Science.gov (United States)

    Grossi, Claudia; Morguí, Josep Anton; Curcoll, Roger; Àgueda, Alba; Arnold, Delia; Batet, Oscar; Cañas, Lidia; Nofuentes, Manel; Occhipinti, Paola; Vogel, Felix; Vargas, Arturo; Rodó, Xavier

    2014-05-01

    The Gredos and Iruelas station (GIC3) is part of the IC3 (Institut Català de Ciències del Clima) atmospheric monitoring network. This station is located in the Gredos Natural Park (40.22º N; -5.14º E) in the Spanish central plateau. The IC3 network consists of 8 stations distributed across Spain. It has been developed with the aim of studying climatic processes and the responses of impacted systems at different temporal and spatial scales. Since 2012, CO2, CH4, 222Rn (a natural radioactive gas) and meteorological variables are continuously measured at GIC3 at 20 m a.g.l. (1100 m a.s.l.). Furthermore, 4-days backward simulations are run daily for each IC3 station using the FLEXPART model. Simulations use ECMWF meteorological data as input and a horizontal spatial resolution of 0.2 degrees. The Laboratory of the Atmosphere and the Oceans (LAO) of the IC3 has elaborated a new approach to evaluate the local or remote greenhouse gases emissions using the radon gas as tracer and the atmospheric particles transport model FLEXPART under nocturnal and winter conditions. The ratios between the normalized and rescaled measured concentrations of CH4 and 222Rn during nocturnal hours (21h, 00h, 03h and 06h) and in the winter season, in order to reduce local radon flux and methane source due to seasonal livestock migration and to get stable atmospheric conditions, have been analyzed in relation to the influence of the local area (set to an initial dimension of 20x20 km2). The influence area (IA) has been defined as the percentage of the ratio between the residence time of the fictitious particles released in FLEXPART simulations over the area of interest (TLocal Area) and the residence time of these fictitious particles over the total area included in the simulation (TTotal Area ), i.e. IA = (TLocal Area/TTotal Area * 100). First results considering an area of interest of 20x20 km2 show a linear increase of the radon concentration with IA until reaching a maximum when IA is

  2. Dependence of indoor 222Rn level on building materials

    International Nuclear Information System (INIS)

    Tso, M.W.; Ng, C.; Leung, J.K.C.

    1993-01-01

    The radionuclide contents of typical building materials used in Hong Kong were studied by γ spectroscopic analysis. The physical properties of these building materials affecting the production and transportation of 222 Rn to the surrounding air were examined; these include the emanation coefficient of 2 '2 2 Rn of the material, the diffusion coefficient of 222 Rn in the material and the effect of surface coating and temperature on the rate of 222 Rn exhalation. Results obtained in this study explain the indoor 222 Rn concentration observed in our previous surveys and also suggest that the main source of indoor 222 Rn in Hong Kong is building material. (3 figs., 4 tabs.)

  3. Observation and modeling of 222Rn daughters in liquid nitrogen

    International Nuclear Information System (INIS)

    Frodyma, N.; Pelczar, K.; Wójcik, M.

    2014-01-01

    The results of alpha spectrometric measurements of the activity of 222 Rn daughters dissolved in liquefied nitrogen are presented. A direct detection method of ionized alpha-emitters from the 222 Rn decay chain ( 214 Po and 218 Po) in a cryogenic liquid in the presence of an external electric field is shown. Properties of the radioactive ions are derived from a proposed model of ion production and transport in the cryogenic liquid. Ionic life-time of the ions was found to be on the order of 10 s in liquid nitrogen (4.0 purity class). The presence of positive and negative ions was observed. - Highlights: • A direct detection method of the alpha-emitters in a cryogenic liquid is shown. • We examine electrostatic drifting of the radioactive ions in liquid nitrogen. • The ions belong to the Radon-222 decay chain; Radon-222 is dissolved in the liquid. • The model of the ions production and behaviour in the liquid is proposed. • The ion production significantly depends on the nuclear decay type (alpha or beta)

  4. 222Rn in the Antarctic Peninsula during 1986

    International Nuclear Information System (INIS)

    Pereira, E.B.; Setzer, A.W.; Cavalcanti, I.F.A.

    1988-01-01

    222 Rn was continuously measured at the Brazilian Antarctic Station (62 0 S, 58 0 W) during the year of 1986. Baseline radon concentration averaged 0.02 Bq.m -3 with surges peaking 0.4 Bq.m -3 . The data exhibited a characteristic periodicity of about 25 days and a strong positive association with short term fluctuations of atmospheric temperature. No seasonal variations of radon were observed. Interpretation of the radon surges with reference to synoptic charts and weather satellite pictures showed that the continental influence of radon at the Antarctic Peninsula is very small and comes only from the tip of the South American cone. (author)

  5. Concentration of 222Rn in drinking water of the Zacatecas City, measured by liquid scintillation and associated dose

    International Nuclear Information System (INIS)

    Arevalo B, C. A.; Lopez del R, H.; Davila R, J. I.; Mireles G, F.; Pinedo V, J. L.; Rios M, C.; Saucedo A, S. A.

    2017-09-01

    A study was carried out to determine the concentration of 222 Rn in samples of drinking water collected from different homes in the Zacatecas city, Mexico, whose main source of supply is groundwater. The 222 Rn radioactive gas is a product of the decay series of 238 U and is considered one of the main sources of natural radiation, since it contributes almost half of the radiation dose that a person will receive throughout his life. The 222 Rn originates in the rocks of the aquifers and dissolves in the water, which is later integrated into the distribution network of the public supply that supplies the entire population. Exposure to ionizing radiation that 222 Rn and its offspring emit can damage the DNA molecule, inducing the possible appearance of cancer. Has been demonstrated by various epidemiological studies carried out in uranium mines workers in different parts of the world, that this exposure increases the incidence of lung cancer, placing 222 Rn and their offspring as the second main cause of this type of cancer, after smoking habit. Using the technique of solvent extraction of 222 Rn in water and liquid scintillation spectrometry, water collected from 14 different households was sampled and analyzed. The average of the measured activity of 222 Rn was 2.09 Bq/L and the annual effective dose per water intake attributable to that concentration of 6.07 mSv/a. The concentration of 222 Rn in water and the annual effective dose are below 11 Bq/L and 50 mSv/a, such concentrations are the maximum limits established by the Unites States Environmental Protection Agency (US EPA) and the ICRP, respectively. The concentration of 222 Rn that is transferred from the water to the air inside a house was also calculated and the radiation dose that this concentration causes by inhalation, being 0.209 Bq/m 3 and 1,463 μ Sv a, respectively. (Author)

  6. Evaluate transport processes in MERRA driven chemical transport models using updated 222Rn emission inventories and global observations

    Science.gov (United States)

    Zhang, B.; Liu, H.; Crawford, J. H.; Fairlie, T. D.; Chen, G.; Chambers, S. D.; Kang, C. H.; Williams, A. G.; Zhang, K.; Considine, D. B.; Payer Sulprizio, M.; Yantosca, R.

    2015-12-01

    Convective and synoptic processes play a major role in determining the transport and distribution of trace gases and aerosols in the troposphere. The representation of these processes in global models (at ~100-1000 km horizontal resolution) is challenging, because convection is a sub-grid process and needs to be parameterized, while synoptic processes are close to the grid scale. Depending on the parameterization schemes used in climate models, the role of convection in transporting trace gases and aerosols may vary from model to model. 222Rn is a chemically inert and radioactive gas constantly emitted from soil and has a half-life (3.8 days) comparable to synoptic timescale, which makes it an effective tracer for convective and synoptic transport. In this study, we evaluate the convective and synoptic transport in two chemical transport models (GMI and GEOS-Chem), both driven by the NASA's MERRA reanalysis. Considering the uncertainties in 222Rn emissions, we incorporate two more recent scenarios with regionally varying 222Rn emissions into GEOS-Chem/MERRA and compare the simulation results with those using the relatively uniform 222Rn emissions in the standard model. We evaluate the global distribution and seasonality of 222Rn concentrations simulated by the two models against an extended collection of 222Rn observations from 1970s to 2010s. The intercomparison will improve our understanding of the spatial variability in global 222Rn emissions, including the suspected excessive 222Rn emissions in East Asia, and provide useful feedbacks on 222Rn emission models. We will assess 222Rn vertical distributions at different latitudes in the models using observations at surface sites and in the upper troposphere and lower stratosphere. Results will be compared with previous models driven by other meteorological fields (e.g., fvGCM and GEOS4). Since the decay of 222Rn is the source of 210Pb, a useful radionuclide tracer attached to submicron aerosols, improved

  7. Measurements of Rn-222, Rn-220 and their decay products in the environmental air of the high background radiation areas in Yangjiang, China

    International Nuclear Information System (INIS)

    Yuan Yongling; Shen Tong; Morishima, Hiroshige; Koga, Taeko; Wei Luxin; Sugahara, Tsutomu

    2000-01-01

    For the renewal of dose estimation from internal irradiation in the high background radiation areas (HBRA) of Yangjiang, the measurements of radon, thoron and their decay products in the environmental air were conducted, including: integrating measurements of Rn-222 and Rn-220 concentrations; equilibrium factor F for Rn-222 and alpha-potential energy value of Rn-220; external gamma radiation in places where radon measurements were undertaken; cumulative exposure to indoor radon for each family in a case-control study on lung cancer. The Rn-Tn cup monitor method was used for the integrating measurement of Rn-222 and Rn-220 concentration. An alpha track detector was used for the integration measurement of Rn-222 concentration in the case-control study on lung cancer. The results of measurements show that although the investigated areas are located between the Equator and the Tropic of Cancer, and that people live in well-ventilated dwellings, the concentrations of radon, especially of Rn-220 are significantly higher in the indoor air of HBRA than those in the control area. The value of equilibrium factors for Rn-222, the alpha potential energy of decay products from Rn-222 and Rn-220 are determined. (author)

  8. Exploring atmospheric radon with airborne gamma-ray spectroscopy

    Science.gov (United States)

    Baldoncini, Marica; Albéri, Matteo; Bottardi, Carlo; Minty, Brian; Raptis, Kassandra G. C.; Strati, Virginia; Mantovani, Fabio

    2017-12-01

    222Rn is a noble radioactive gas produced along the 238U decay chain, which is present in the majority of soils and rocks. As 222Rn is the most relevant source of natural background radiation, understanding its distribution in the environment is of great concern for investigating the health impacts of low-level radioactivity and for supporting regulation of human exposure to ionizing radiation in modern society. At the same time, 222Rn is a widespread atmospheric tracer whose spatial distribution is generally used as a proxy for climate and pollution studies. Airborne gamma-ray spectroscopy (AGRS) always treated 222Rn as a source of background since it affects the indirect estimate of equivalent 238U concentration. In this work the AGRS method is used for the first time for quantifying the presence of 222Rn in the atmosphere and assessing its vertical profile. High statistics radiometric data acquired during an offshore survey are fitted as a superposition of a constant component due to the experimental setup background radioactivity plus a height dependent contribution due to cosmic radiation and atmospheric 222Rn. The refined statistical analysis provides not only a conclusive evidence of AGRS 222Rn detection but also a (0.96 ± 0.07) Bq/m3 222Rn concentration and a (1318 ± 22) m atmospheric layer depth fully compatible with literature data.

  9. Tracing submarine groundwater discharge in the NE Gulf of Mexico by 222Rn

    International Nuclear Information System (INIS)

    Young, J.E.; Burnett, W.C.; Chanton, J.P.; Cable, P.H.; Corbett, D.R.

    1993-01-01

    Inputs of freshwater and dissolved components to the ocean by submarine groundwater discharge (SGD) have been largely neglected as source functions for biogeochemical budgets. In order to locate and quantify groundwater inputs, a tracing technique has been developed using 222 Rn, a member of the natural 238 U decay-series. Because 222 Rn has a short half-life (t 1/2 = 3.84 days), is an inert gas, is relatively easy to measure at low concentrations, and has concentrations in groundwater several orders of magnitude greater than seawater, it should make an excellent tracer. Excess 222 Rn concentrations far above ''normal'' ocean values were found in the bottom waters of the northeastern Gulf of Mexico, which suggests this region has significant groundwater discharge. After measuring high water column inventories of excess 222 Rn in this region, an advection/diffusion model was applied to evaluate potential benthic sources of radon. The model is designed to account for sediment diffusion of radon and includes a groundwater term for advective flow into the overlying water. Flow rates and concentrations are adjusted in the model to balance the large difference in the measured water column inventories and the inventory predicted by sediment diffusion alone. The vertical diffusive/advective transport determines the shape of the concentration gradient and fluxes at the sediment-water interface are calculate based on these terms. The authors work shows that SGD could account for as much as 95% of the radon inventory in these offshore waters

  10. Measurement of 222Rn in soil concentrations in interstitial air

    International Nuclear Information System (INIS)

    Duenas, C.; Fernandez, M.C.; Carretero, J.; Liger, E.

    1996-01-01

    Measurements of 222 Rn soil concentrations were made by inserting stainless-steel sampling tubes into the soil. The samples of the soil interstitial air were taken in to pre-evacuated 1 L glass flasks. The glass flasks are cylindrical and coated with a film of ZnS(Ag). 222 Rn was measured by counting the alpha particles emitted by 222 Rn and its daughter products, 218 Po and 214 Bi, when they reached radioactive equilibrium. Measurements of 222 Rn gas concentrations in the soil air interstices by the method at different depths were used to calculate the diffusion coefficient of the 222 Rn in the soil air. This study has been carried out for diverse soils. (Author)

  11. Development, implementation and utilization of 210Pb in vivo measurement techniques as indicator of human being exposure to 222Rn - evaluation of associated parameters

    International Nuclear Information System (INIS)

    Dantas, Ana Leticia Almeida

    2005-01-01

    Radon and its decay products are present in the atmosphere and are the most important contributors for the internal exposure of humans to natural radiation. The execution of in vivo measurements of 210 Pb in the population and in individuals occupationally exposed in underground mines has been studied and recommended as one of the procedures for the estimation of the exposure to 222 Rn. The metabolism of 210 Pb and its distribution within the human body, mainly deposited in the bone tissue, suggests the regions of skull and knee as the most suitable for the in vivo monitoring of such radionuclide. A radiological survey in non uranium mines in Brazil indicated that an underground coal mine in the State of Parana, in the south of Brazil, had high radon concentration. The aim of this work were: (1) To investigate whether underground coal miners may also have elevated 210 Pb in the skeleton as a result of occupational exposure to radon in the coal mine; (2) To estimate the committed equivalent dose and the committed effective dose in different incorporation scenarios using a computer code. The calibration and the in vivo measurements of underground coal miners were performed in the IRD-CNEN Whole Body Counter shielded room using an array of four high resolution germanium detectors. The detection system was positioned at the head and knee geometries. The minimum detectable quantity of 210 Pb in the skeleton using this methodology was (50 Bq) and the positive results were verified using a mathematical method that applies a moving median smoothing function to the total spectrum for each measurement. In vivo measurements of 210 Pb in 6 out of the 32 underground coal miners ranged between 83 Bq and 164 Bq suggesting that these workers received significant occupational cumulative exposure to 222 Rn. The simulation of some exposure patterns of 222 Rn progeny and 210 Pb incorporation showed that the most important contribution for 210 Pb skeleton deposition was the intake of

  12. Dry soil diurnal quasi-periodic oscillations in soil 222Rn concentrations

    International Nuclear Information System (INIS)

    Tommasone Pascale, F.; De Francesco, S.; Carbone, P.; Cuoco, E.; Tedesco, D.

    2014-01-01

    222 Rn concentrations have been monitored during the dry season in August 2009 and August 2010, in a reworked alluvial-pyroclastic soil of the Pietramelara Plain, in Southern Italy, with the aim of determining the role of atmospheric factors in producing the quasi-periodic oscillations in soil 222 Rn concentrations reported in the literature. In this study we present the results of a detailed analysis and matching of soil 222 Rn concentrations, meteorological and solar parameters where the observed oscillations feature a characteristic behavior with second order build-up and depletion limbs, separated by a daily maximum and minimum. All these features are clearly shown to be tied to sunrise and sunset timings and environmental radiative flux regimes. Furthermore, a significant, and previously unreported, second order correlation (r 2  = 0.73) between daily maximum hourly global radiation and the daily range of soil 222 Rn concentrations has been detected, allowing estimates of the amplitude of these oscillations to be made from estimated or measured solar radiation data. The correlation has been found to be valid even in the presence of persistent patchy daytime cloudiness. In this case a daytime prolongation of the night-time build up stage and an attenuation or even suppression of daytime depletion is observed (a previously unreported effect). Neither soil cracking, nor precipitation, both suggested in some studies as causative factors for these oscillations, during the dry season appear to be necessary in explaining their occurrence. We also report the results of an artificial shading experiment, conducted in August 2009, that further support this conclusion. As soil 222 Rn concentrations during the dry season show a characteristic daily cycle, radon monitoring in soils under these conditions necessarily has to be gauged to the timings of the daily maximum and minimum, as well as to the eventual occurrence of cloudiness and to its related effects, in order to

  13. Concentration of {sup 222}Rn in drinking water of the Zacatecas City, measured by liquid scintillation and associated dose; Concentracion de {sup 222}Rn en agua potable de la Ciudad de Zacatecas, medida por centelleo liquido y dosis asociada

    Energy Technology Data Exchange (ETDEWEB)

    Arevalo B, C. A.; Lopez del R, H.; Davila R, J. I.; Mireles G, F.; Pinedo V, J. L.; Rios M, C.; Saucedo A, S. A., E-mail: cesar_arevalob@outlook.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2017-09-15

    A study was carried out to determine the concentration of {sup 222}Rn in samples of drinking water collected from different homes in the Zacatecas city, Mexico, whose main source of supply is groundwater. The {sup 222}Rn radioactive gas is a product of the decay series of {sup 238}U and is considered one of the main sources of natural radiation, since it contributes almost half of the radiation dose that a person will receive throughout his life. The {sup 222}Rn originates in the rocks of the aquifers and dissolves in the water, which is later integrated into the distribution network of the public supply that supplies the entire population. Exposure to ionizing radiation that {sup 222}Rn and its offspring emit can damage the DNA molecule, inducing the possible appearance of cancer. Has been demonstrated by various epidemiological studies carried out in uranium mines workers in different parts of the world, that this exposure increases the incidence of lung cancer, placing {sup 222}Rn and their offspring as the second main cause of this type of cancer, after smoking habit. Using the technique of solvent extraction of {sup 222}Rn in water and liquid scintillation spectrometry, water collected from 14 different households was sampled and analyzed. The average of the measured activity of {sup 222}Rn was 2.09 Bq/L and the annual effective dose per water intake attributable to that concentration of 6.07 mSv/a. The concentration of {sup 222}Rn in water and the annual effective dose are below 11 Bq/L and 50 mSv/a, such concentrations are the maximum limits established by the Unites States Environmental Protection Agency (US EPA) and the ICRP, respectively. The concentration of {sup 222}Rn that is transferred from the water to the air inside a house was also calculated and the radiation dose that this concentration causes by inhalation, being 0.209 Bq/m{sup 3} and 1,463 μ Sv a, respectively. (Author)

  14. Recent Swedish experiences in 222Rn control

    International Nuclear Information System (INIS)

    Swedjemark, G.A.; Maekitalo, A.

    1990-01-01

    Swedish local authorities are responsible for decreasing 222 Rn progeny concentrations in homes in their municipalities. To obtain an overall view of their experiences, concerned national authorities sent a questionnaire in 1986 to local authorities. The results were intended to form one basis for decisions by the government regarding revised statements on financial contributions, limits, etc. The results were also intended to be of use to national authorities in determining limits and recommendations and to local authorities in their field work. One result of the survey was an enhanced interest in the Rn problem among Swedish politicians and the mass media. This increased attention resulted in new plans for continued work to decrease Rn levels indoors during 1987-1989, on both a national and a local level. The experiences of the local authorities show that Rn progeny concentrations decreased to below the design level in 95% of newly built houses investigated. It was also found that Rn progeny concentrations were below the limit for reconstruction in 53% of existing homes that previously had levels exceeding the limit

  15. Activated charcoal adsorber bed as a 222Rn hold up system for application in uranium mining industries

    International Nuclear Information System (INIS)

    Sudeep Kumara, K.; Karunakara, N.; Sahoo, B.K.; Gaware, J.J.; Sapra, B.K.; Mayya, Y.S.

    2018-01-01

    222 Rn, produced due to the decay of 226 Ra, can accumulate to high concentrations, and if adequate ventilation is not provided the workers may inhale the 222 Rn laden air, which would result in elevated inhalation dose in Uranium mining and milling operations. Similarly, in thorium mining and processing plants, the 220 Rn generated during monazite processing and thorium handling facility is of concern. In a previous publication it has been shown that adsorption in a flow-through charcoal bed offers an excellent method of alleviating the release of 220 Rn into occupational and public domain. In this paper we examine the utility of TMS as a 222 Rn hold up/delay system by evaluating its performance parameters such as breakthrough time (τ) and adsorption coefficient (K) at different flow rates

  16. Study of natural radioactivity and 222Rn exhalation rate in soil samples for the assessment of average effective dose

    International Nuclear Information System (INIS)

    Bangotra, P.; Mehra, R.; Jakhu, R.; Sahoo, B.K

    2016-01-01

    The natural radioactivity in soil is usually determined from the 226 Ra (Radium), 232 Th (Thorium) and 40 K (potassium). 222 Rn and 220 Rn are produced in soil as a result of the presence of these radionuclides. As 226 Ra decay, the newly created 222 Rn radionuclide recoil from the parent grain and then exhale through the soil. Since 98.5% of radiological effects of 238 U series are produced by 226 Ra and its daughter products. The assessment of gamma radiation dose from natural sources is of particular importance as natural radiation is the largest contributor to the external dose of the world population. Authors are advised to maximize the information content utilizing the full space available. The main objective of the present study is to measure the level of natural radioactivity 226 Ra, 232 Th, 40 K and 222 Rn exhalation rate in the soil samples for health risk assessment

  17. Seasonal and diurnal variation of outdoor radon (222Rn) concentrations in urban and rural area with reference to meteorological conditions

    International Nuclear Information System (INIS)

    Podstawczynska, A.; Pawlak, W.; Kozak, K.; Mazur, J.

    2010-01-01

    The objective of the study was to investigate temporal variability of outdoor radon ( 222 Rn) concentration registered in the center of Lodz (urban station), at Ciosny (rural station) and Krakow (suburban station) in relation to meteorological parameters (i.e. air temperature, temperature vertical gradient, wind speed, soil heat flux, volumetric water content in soil) with special consideration of urban-rural differences. Continuous measurements of 222 Rn concentration (at 60 min intervals) were performed at a height of 2 m above the ground using AlphaGUARD PQ2000PRO (ionization chamber) from January 2008 to May 2009. 222 Rn levels were characterized by a diurnal cycle with an early morning maximum and a minimum in the afternoon. The well-marked 24 h pattern of radon concentration occurred in summer at anticyclonic weather with cloudless sky, light wind and large diurnal temperature ranges. The urban measurement site was characterized by the lowest atmospheric 222 Rn concentration and an urban-rural differences of radon levels increased from winter to summer and during the nighttime periods. The maximum contrasts of 222 Rn levels between Lodz and Ciosny, reaching - 30 Bq m -3 , were registered in June and July during the urban heat island (UHI) phenomenon (a positive thermal anomaly of a city if compared to rural area) and strong thermal inversion near the ground in the rural area. (authors)

  18. Assessment of Effective Dose Equivalent of Indoor 222Rn Daughters in Inchass

    International Nuclear Information System (INIS)

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

    2000-01-01

    The dominant component of natural radiation dose for the general population comes from the radon gas 222 Rn and its short-lived decay products, Ra A ( 214 Po), Ra B ( 214 Pb), Ra C ( 214 Bi), Ra C( 214 Po) in the breathing air. The objective of the present work is to assess the affective dose equivalent of the inhalation exposure of indoor 222 Rn for occupational workers. Average indon concentrations (Bqm -3 ) were monitored in several departments in Nuclear Research Center by radon monitor. We have calculated the lung dose equivalent and the effective dose equivalent for the Egyptian workers due to inhalation exposure of an equilibrium equivalent concentrations of radon daughters which varies from 0.27 to 2.5 mSvy -1 and 0.016 to 0.152mSvy -1 respectively. The annual effective doses obtained are within the accepted range of ICRP recommendations

  19. Contribution of 222Rn in domestic water supplies to 222Rn in indoor air in Colorado homes

    International Nuclear Information System (INIS)

    Lawrence, E.P.; Wanty, R.B.; Nyberg, P.

    1992-01-01

    The contribution of 222Rn from domestic water wells to indoor air was investigated in a study of 28 houses near Conifer, CO. Air concentrations determined by alpha-track detectors (ATDs) and continuous radon monitors were compared with the predictions of a single-cell model. In many of the houses, the water supply was shown to contribute significantly to levels of indoor 222Rn. The data from the ATD study were augmented with a continuous monitoring study of a house near Lyons, CO. The well water in that house has the highest known concentration of 222Rn in water yet reported (93 MBq m-3). The temporal pattern in the indoor 222Rn concentration corresponds to water-use records. In general, it is difficult to quantify the proportion of indoor radon attributable to water use. Several lines of evidence suggest that the single-cell model underestimates this proportion. Continuous-monitoring data, although useful, are impractical due to the cost of the equipment. We propose a protocol for 222Rn measurement based on three simultaneous integrating radon detectors that may help estimate the proportion of indoor 222Rn derived from the water supply

  20. 222Rn Measurements in Dwellings of Argentina

    International Nuclear Information System (INIS)

    Gnoni, G.; Canoba, A.; Czerniczyniec, M.

    2011-01-01

    Radon gas ( 222 Rn) is responsible of about fifty per cent of the world population dose due to natural sources, being the most important pathway the inhalation of radon progeny, specially indoors. Radon concentration has been measured in dwellings at different locations in Argentina. The places selected to be evaluated are representative of the different geologic zones of the country. Near 3000 dwellings have been analyzed since 1983 up today. The measuring methods used in this case were track etched detectors, electrets and detectors based on activated charcoal adsorption. Two different methods with track etched detectors were used: a simple one, which determines only the average radon concentration, and a second one that measures both radon concentration and the equilibrium factor (F) between radon and its daughters. The last one is a method that uses two Makrofol passive track detectors in the same device. The average radon concentration value obtained from all the dwellings evaluated was 44.2 Bq.m-3. The annual effective dose calculated from this average concentration, using a dosimetric factor of 25 μSv.a- 1. (Bq.m -3 ) -1 , which assumes an equilibrium factor of 0.4, was 1.11 mSv. The average value obtained from the 222 dwellings evaluated by the second method was 49.3 Bq.m -3 and 0,37 the equilibrium factor, resulting the annual effective dose estimated 1,44 mSv. The measured equilibrium factor of 0,37 allows us to verify the assumed equilibrium factor of 0,4. Finally, radon levels in dwellings of Argentina are within the acceptable values for population, not being necessary to implement remedial actions, except in isolate cases that are still under study. (authors)

  1. Dose by 222 Rn in houses of the Chihuahua city

    International Nuclear Information System (INIS)

    Colmenero S, L.H.; Talamantes F, C.; Villalba, M.L.; Dobson, P.F.; Ortalejo M, B.

    2007-01-01

    of the radon was made every 10 minutes during three continuous days, with the AlphaGUARD Pro2000 equipment that also measures atmospheric parameters. The obtained data were analyzed with the Genitron software and was analyzed the variation of the radon concentration with the atmospheric parameters and a hours in that the person is in the room. Finally they were carried out the dosimetry calculations due to the radon in air, adding it with the dose received by floor and water due to the natural radionuclides. As it was expected, the city of Chihuahua when being on an uranifer floor and the materials of construction of housings are elaborated starting from this floor, high concentrations were presented of 222 Rn. The third part of the houses had a bigger average to the 148 Bq/m 3 in air, with values average for the whole day of up to 276 Bq/m 3 , as well as maxima values near to 900 Bq/m 3 . When making the calculation of the concentration for the night and dawn that it is when the one inhabitant remains in the room and that to avoid the cold he closes doors and windows, the radon concentration ascended until values of 305 Bq/m 3 . The calculation of the dosimetry was in high values for the radon of until 3.2 mSv/year that adding to the floor values (0.63 mSv/year) and water (0.016 mSv/year) it gives a value of 3.85 mSv/year, considering these values very superior to those registered in other cities of the country reported in the bibliography or by the CNSNS. (Author)

  2. Exposure of burrowing mammals to {sup 222}Rn

    Energy Technology Data Exchange (ETDEWEB)

    Beresford, N.A., E-mail: nab@ceh.ac.uk [NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Av. Bailrigg, Lancaster LA1 4AP (United Kingdom); Barnett, C.L. [NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Av. Bailrigg, Lancaster LA1 4AP (United Kingdom); Vives i Batlle, J. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, 2400 Mol (Belgium); Potter, E.D. [NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Av. Bailrigg, Lancaster LA1 4AP (United Kingdom); Ibrahimi, Z.-F. [Health Protection Agency, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot OX11 0RQ (United Kingdom); Barlow, T.S.; Schieb, C.; Jones, D.G. [British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG (United Kingdom); Copplestone, D. [School of Natural Sciences, University of Stirling, Stirling FK9 4LA (United Kingdom)

    2012-08-01

    Estimates of absorbed dose rates to wildlife from exposure to natural background radionuclides are required to put estimates of dose rates arising from regulated releases of radioactivity and proposed benchmarks into context. Recent review papers have estimated dose rates to wildlife from {sup 40}K, and {sup 238}U and {sup 232}Th series radionuclides. However, only one study previous has considered the potential dose rates to burrowing animals from inhaled {sup 222}Rn and its daughter products. In this paper we describe a study conducted at seven sites in northwest England. Passive track etch detectors were used to measure the {sup 222}Rn concentrations in artificial burrows over a period of approximately one year. Results suggest that absorbed dose rates to burrowing mammals as a consequence of exposure to {sup 222}Rn are likely to be at least an order of magnitude higher than those suggested in previous evaluations of natural background exposure rates which had omitted this radionuclide and exposure pathway. Dose rates in some areas of Great Britain will be considerably in excess of incremental no-effects benchmark dose rates suggested for use as screening levels. Such advised benchmark dose rates need to be better put into context with background dose rates, including exposure to {sup 222}Rn, to ensure credibility; although the context will be determined by the purpose of the benchmark and the assessment level. - Highlights: Black-Right-Pointing-Pointer Determined {sup 222}Rn concentrations in artificial burrows. Black-Right-Pointing-Pointer Estimated dose rates to burrowing mammals from inhaled {sup 222}Rn and daughter products. Black-Right-Pointing-Pointer {sup 222}Rn likely to dominate exposure of burrowing mammals due to natural radionuclides.

  3. Preliminary experiences with 222Rn gas in Arizona homes

    International Nuclear Information System (INIS)

    Kearfott, K.J.

    1989-01-01

    Results of a survey of 222Rn gas using four-day charcoal canister tests in 759 Arizona homes are reported. Although the study was not random with respect to population or land area, it was useful in identifying areas at risk and locating several homes having elevated indoor 222Rn air concentrations. Approximately 18% of the homes tested exceeded 150 Bq m-3 (4 pCi L-1), with 7% exceeding 300 Bq m-3 (8 pCi L-1). Several Arizona cities had larger fractions of homes exceeding 150 Bq m-3 (4 pCi L-1), such as Carefree and Cave Creek (23%), Paradise Valley (30%), Payson (33%), and Prescott (31%). The Granite Dells and Groom Creek areas of Prescott had in excess of 40-60% of the houses tested exceeding 150 Bq m-3 (4 pCi L-1). Elevated 222Rn concentrations were measured for a variety of home types having different construction materials. Private well water was identified as a potentially significant source of 222Rn gas in Prescott homes, with water from one well testing over 3.5 MBq m-3 (94,000 pCi L-1). A 222Rn concentration in air exceeding 410,000 Bq m-3 (11,000 pCi L-1) was measured using a four-day charcoal canister test in a house in Prescott which had a well opening into a living space. Additional measurements in this 150-m3 dwelling revealed a strikingly heterogeneous 222Rn concentration. The excessive 222Rn level in the dwelling was reduced to less than 190 Bq m-3 (5.2 pCi L-1) by sealing the well head with caulking and providing passive ventilation through a pipe

  4. Measurements of indoor 222Rn concentration in two art galleries

    International Nuclear Information System (INIS)

    Carneiro, Luana Gomes; Braz, Delson; Jesus, Edgar Francisco de; Cunha, Kenya Dias da; Medeiros, Geiza; Zouain, Felipe; Pitassi, Gabriel; Leite, Carlos Barros; Cardoso, Katia

    2009-01-01

    It is point out that radon and their decay products in environment give high dose to human lung. Studies indicate that the indoor radon inhalation by humans has been considered probably the second most important cause of lung cancer after of smoking. A passive-type radon detector was used for measuring indoor radon concentration in two art galleries at Rio de Janeiro city during 90 days January to March, 2009. The aim of this study is to evaluate the occupational and public radon exposure in art galleries and museums. This paper shows the preliminary results of samples collected at two art galleries located in Gavea, Rio de Janeiro city. 30 LEXAN (GE) track detectors were exposed in the air (indoor as well as outdoor). The samples were collected in the same building which is a construction of XIX century. The analysis of the results suggests that the 222 Rn concentration levels are different in both sampling site, in closed environmental, demonstrating that, although the construction materials are the same the absence of circulating air is a factor very important to increase the concentration of indoor Rn. (author)

  5. Prediction of 222 Rn exhalation rates from phosphogypsum based stacks. Part I: parametric mathematical modeling

    International Nuclear Information System (INIS)

    Rabi, Jose A.; Mohamad, Abdulmajeed A.

    2004-01-01

    Radon-222 is a radionuclide exhaled from phosphogypsum by-produced at phosphate fertilizer industries. Alternative large-scale application of this waste may indicate a material substitute for civil engineering provided that environmental issues concerning its disposal and management are overcome. The first part of this paper outlines a steady-state two-dimensional model for 222 Rn transport through porous media, inside which emanation (source term) and decay (sink term) exist. Boussinesq approach is evoked for the laminar buoyancy-driven interstitial air flow, which is also modeled according to Darcy-Brinkman formulation. In order to account for simultaneous effects of entailed physical parameters, governing equations are cast into dimensionless form. Apart from usual controlling parameters like Reynolds, Prandtl, Schmidt, Grashof and Darcy numbers, three unconventional dimensionless groups are put forward. Having in mind 222 Rn transport in phosphogypsum-bearing porous media, the physical meaning of those newly introduced parameters and representative values for the involved physical parameters are presented. A limiting diffusion-dominated scenario is addressed, for which an analytical solution is deduced for boundary conditions including an impermeable phosphogypsum stack base and a non-zero fixed concentration activity at the stack top. Accordingly, an expression for the average Sherwood number corresponding to the normalized 222 Rn exhalation rate is presented

  6. Measurement of 222Rn flux, 222Rn emanation and 226Ra concentration from injection well pipe scale

    International Nuclear Information System (INIS)

    Rood, A.S.; Kendrick, D.T.

    1996-01-01

    The presence of Naturally Occurring Radioactive Material (NORM) has been recognized since the early 1930s in petroleum reservoirs and in oil and gas production and processing facilities. NORM was typically observed in barite scale that accumulated on the interior of oil production tubing and in storage tank and heater-treater separation sludge. Recent concern has been expressed over the health impacts from the uncontrolled release of NORM to the public. There are several potential exposure pathways to humans from oil-field NORM. Among these is inhalation of radon gas and its daughter products. For this exposure pathway to be of any significance, radon must first be released from the NORM matrix and diffuse in free air. The radon emanation fraction refers to the fraction of radon atoms produced by the decay of radium, that migrate from the bulk material as free gaseous atoms. The purpose of this investigation was to characterize the radon release rates from NORM-scale contaminated production tubing being stored above ground, characterize the radon emanation fraction of the bulk scale material when removed from the tubing, and characterize the radium concentrations of the scale. Accurate characterization of 222 Rn emanation fractions from pipe scale may dictate the type of disposal options available for this waste. Characterization of radon release from stored pipes will assist in determining if controls are needed for workers or members of the public downwind from the source. Due to the sensitive nature of this data, the location of this facility is not disclosed

  7. Investigation of the application of 4He/36Ar ratio and 222Rn measurements to the exploration for uranium mineral deposits. Final report

    International Nuclear Information System (INIS)

    Schutz, D.F.

    1981-06-01

    The sites of three uranium ore deposits of diverse geologic settings have been studied by a limited sampling of near-surface and subsurface soil gas, soil, and core materials to determine whether the uranium decay products 226 Ra, 222 Rn, 210 Pb, and 4 He may be useful as indicators of subsurface uranium mineralization. It was concluded that in the near-surface environment of all three sites, the 222 Rn levels were less than would be expected from closed system equilibrium with the soil itself and any anomalies with the underlying ore is fortuitous and does not provide a basis for guiding an exploration drilling operation. In contrast to the results for 222 Rn, the results for adsorbed 210 Pb show a number of locations with 210 Pb concentrations in the near-surface environment in excess of that expected from closed systems accumulations. However, the value of 210 Pb measurements as indicators of subsurface uranium deposits is considered inconclusive by the author. Radium-226 distributions in the near-surface samples at the three sites do not show significant patterns that are related to underlying ore. Most soil-gas samples have 4 He/ 36 Ar ratios significantly in excess of atmospheric levels. However, the lack of consistent relation to uranium mineralization either in areal or vertical distribution, coupled with the ability to measure excess 4 He in soils not associated in any way with uranium mineralization leads to the interpretation that much, if not all of the excess 4 He measured in soil gas is the result of in situ formation and not from allogenic sources

  8. Prediction of 222 Rn exhalation rates from phosphogypsum based stacks. Part II: preliminary numerical results

    International Nuclear Information System (INIS)

    Rabi, Jose A.; Mohamad, Abdulmajeed A.

    2004-01-01

    The first part of this paper proposes a steady-state 2-D model for 222 Rn transport in phosphogypsum stacks. In this second part, the dimensionless model equations are solved numerically with the help of an existing finite-volume simulator that has been successfully used to solve heat and mass transfer problems in porous media. As a test case, a rectangular shaped stack is considered in order to verify the ability of the proposed parametric approach to account for concurrent effects on the 222 Rn exhalation into the local atmosphere. Air flow is supposed to be strictly buoyancy driven and the ground is assumed to be impermeable to 222 Rn and at a higher temperature under the stack base. Dimensionless controlling parameters are set to representative values and results are presented for Grashof number in the range 10 6 ≤Gr≤ 10 8 , corresponding to very small to small temperature differences between incoming air and ground underneath the stack base. For the particular set of parameters and inasmuch as Gr increases, streamlines presented basically the same pattern while internal isotherms and iso concentration lines remained almost unchanged. Total average Sherwood number proved to be rather insensitive to Gr while total average Nusselt increased slightly with Gr. (author)

  9. A micromegas detector for {sup 222}Rn emanations measurements

    Energy Technology Data Exchange (ETDEWEB)

    García, J. A.; Garza, J. G.; Irastorza, I. G.; Mirallas, H. [Laboratorio de Física Nuclear y Altas Energías, Universidad de Zaragoza, Zaragoza (Spain)

    2013-08-08

    The {sup 222}Rn emanation has significant contribution in the overall background for rare event searches experiments. In order to measure this emanations a high sensitivity detector has been designed. The detection method is based on the electrostatic collection of the {sup 222}Rn daughters on a Micromegas detector. Using a chamber with a volume of 21.2 l for the collection of {sup 218}Po and {sup 214}Po progeny of {sup 222}Rn and a 12 × 12cm{sup 2} pixelized Micromegas for the α detection. The advantages of the Micromegas detectors are the low intrinsic radioactivity and the track reconstruction of the α’s, having excellent capabilities for event discrimination.

  10. Mineral water 222 Rn activity decrease due to consumption habits

    International Nuclear Information System (INIS)

    Cipriani, Moacir; Taddei, Maria Helena Tirollo; Silva, Nivaldo Carlos da

    2001-01-01

    Mineral waters from the Pocos de Caldas Plateau springs, an elevated region with high natural radioactivity, in the State of Minas Gerais, Brazil, have significant 222 Rn concentration on site. The highest concentration in the waters are from: Fonte Villela - Aguas da Prata (∼ 1000 Bql -1 ); Fonte Grande Hotel - Pocinhos do Rio Verde (∼ 400 Brq -1 ) and Fonte CNEN Lab - Pocos de Caldas (∼ 290 Bql -1 ). These waters are used by the population as drinking water and due to consumption habits, can lead to internal doses above accepted limits for the public. This work deals with the decrease of 222 Rn activity in mineral waters fro two different popular consumption habits, and with the adult effective dose equivalent reduction due to water consumption habits. It has been found that the estimated dose based on the biokinetic Crawford-Brown model, can be one fourth of dose based on 222 Rn activity on site. (author)

  11. Correlation among the terrestrial gamma radiation, the indoor air 222Rn, and the tap water 222Rn in Switzerland

    International Nuclear Information System (INIS)

    Buchli, R.; Burkart, W.

    1989-01-01

    The external gamma radiation and the indoor air Rn (222Rn) concentration were measured in 55 houses of the South East Grisons, the Urseren valley, and the Upper Rhine valley (crystalline subsoils) and in 39 houses of the Molasse basin and the Helvetic nappes (sedimentary subsoils). In homes located on a crystalline subsoil, a mean cellar gamma level of 1.40 mGy y-1 was measured, which is twice the mean gamma level of 0.70 mGy y-1 found in homes built on a sedimentary subsoil. The cellar 222Rn gas concentration is about six times higher in houses with a crystalline subsoil (1232 Bq m-3) than in houses with a sedimentary subsoil (201 Bq m-3). Although a weak correlation is observed between the mean gamma radiation levels and mean cellar 222Rn gas concentrations for the five subregions investigated, the gamma levels and the 222Rn gas concentrations do not correlate for single homes. For the population living on the ground floor of a house with a crystalline subsoil, the gamma radiation and the indoor air 222Rn lead to estimated mean exposures of 1.16 mSv and 9.44 mSv effective dose equivalent per year, respectively. In houses with a sedimentary subsoil, these mean exposures lead to 0.68 mSv y-1 and 3.22 mSv y-1, respectively. A mean tap water 222Rn content of 38.3 Bq L-1 and 10.4 Bq L-1 was measured in 31 villages with a crystalline subsoil and 73 villages with a sedimentary subsoil, respectively. Radon-222 degasing from the tap water into the indoor air leads to an additional exposure of about 0.11 mSv y-1 and 0.03 mSv y-1 in homes with a crystalline subsoil and homes with a sedimentary subsoil, respectively

  12. Assessment of (222)Rn emanation from ore body and backfill tailings in low-grade underground uranium mine.

    Science.gov (United States)

    Mishra, Devi Prasad; Sahu, Patitapaban; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara

    2014-02-01

    This paper presents a comparative study of (222)Rn emanation from the ore and backfill tailings in an underground uranium mine located at Jaduguda, India. The effects of surface area, porosity, (226)Ra and moisture contents on (222)Rn emanation rate were examined. The study revealed that the bulk porosity of backfill tailings is more than two orders of magnitude than that of the ore. The geometric mean radon emanation rates from the ore body and backfill tailings were found to be 10.01 × 10(-3) and 1.03 Bq m(-2) s(-1), respectively. Significant positive linear correlations between (222)Rn emanation rate and the (226)Ra content of ore and tailings were observed. For normalised (226)Ra content, the (222)Rn emanation rate from tailings was found to be 283 times higher than the ore due to higher bulk porosity and surface area. The relative radon emanation from the tailings with moisture fraction of 0.14 was found to be 2.4 times higher than the oven-dried tailings. The study suggested that the mill tailings used as a backfill material significantly contributes to radon emanation as compared to the ore body itself and the (226)Ra content and bulk porosity are the dominant factors for radon emanation into the mine atmosphere.

  13. Monte Carlo simulation of semiconductor detector response to "2"2"2Rn and "2"2"0Rn environments

    International Nuclear Information System (INIS)

    Irlinger, J.; Trinkl, S.; Wielunksi, M.; Tschiersch, J.; Rühm, W.

    2016-01-01

    A new electronic radon/thoron monitor employing semiconductor detectors based on a passive diffusion chamber design has been recently developed at the Helmholtz Zentrum München (HMGU). This device allows for acquisition of alpha particle energy spectra, in order to distinguish alpha particles originating from radon and radon progeny decays, as well as those originating from thoron and its progeny decays. A Monte-Carlo application is described which uses the Geant4 toolkit to simulate these alpha particle spectra. Reasonable agreement between measured and simulated spectra were obtained for both "2"2"0Rn and "2"2"2Rn, in the energy range between 1 and 10 MeV. Measured calibration factors could be reproduced by the simulation, given the uncertainties involved in the measurement and simulation. The simulated alpha particle spectra can now be used to interpret spectra measured in mixed radon/thoron atmospheres. The results agreed well with measurements performed in both radon and thoron gas environments. It is concluded that the developed simulation allows for an accurate prediction of calibration factors and alpha particle energy spectra. - Highlights: • A method was developed to simulate alpha particle spectra from radon/thoron decay. • New monitor features alpha-particle-spectroscopy based on silicon detectors. • A method is presented to quantify radon/thoron concentrations in mixed atmospheres. • The calibration factor can be simulated for various environmental parameters.

  14. Development of method for quantification of 222Rn exhalation ratio at radioactive waste dam and soil study as mitigator material

    International Nuclear Information System (INIS)

    Macacini, Jose Flavio

    2008-01-01

    The Brazilian uranium mining company (INB) processed 2.32 10 6 tons of uranium ore in its ore treatment unit (UTM - Caldas), located in the Pocos de Caldas plateau. During 16 years of operation, this unit discarded 2.39 10 6 tons of solid waste in a tailing dam, with an average activity concentration of 226 Ra of 7311 ± 184 Bq kg -1 . Most of the atoms of 222 Rn generated from the radioactive waste of the tailing dam remain bounded to the mineral structure. However, a fraction of these atoms can be released from the mineral structure and then emanate. Reaching the porous space of the waste piles, the 222 Rn moves towards the interface waste-atmosphere, exhaling into the atmosphere. The featuring properties of the 222 Rn transport and the biological damage caused by its progeny transform this small chain of radionuclides into a scourge of nature. Because of that, the dry area of the tailing dam was the scope of this work. A methodology was developed for quantifying the exhalation rate of 222 Rn. Moreover, the soil from its surroundings was experimentally evaluated as a cover material to reduce the exhalation of 222 Rn. A collector of 222 Rn was developed, being denominated 607. This collector was proved to be exact and precise after laboratory tests, when a standard for 222 Rn exhalation was prepared with caldasite, an uranium ore with high concentration of 226 Ra (26611 ± 581 Bq kg -1 ), crushed to the granulometric interval from 1.168 mm to 0.589 mm. The results of 222 Rn exhalation rate using the collector 607 were not influenced by the adsorption of water steam, considering sampling periods lower than 5 days and mass of water steam lower than 7 g. Sampling for measuring 222 Rn exhalation rates in the dry area of the tailing dam was carried out using the collector 607, following the experimental design established by the United States Environmental Protection Agency (US EPA). The average exhalation rate in the west part of the tailing dam was 1.30 ± 1.24 Bq m

  15. Detection system for continuous 222Rn monitoring in waters

    International Nuclear Information System (INIS)

    Holy, K.; Patschova, E.; Bosa, I.; Polaskova, A.; Hola, O.

    2001-01-01

    This contribution presents one of the high-sensitive systems of continuous radon monitoring in waters. The device can be used for the continual control of 222 Rn activity concentration in water sources, for a study of the daily and seasonal variations of radon activity concentration in water systems, for the determination of the infiltration time of surface water into the ground water and for the next untraditional applications. (authors)

  16. 222 Rn determination and physicochemical characteristic and biological in aquifers in the Toluca Valley

    International Nuclear Information System (INIS)

    Hernandez A, A.

    1998-01-01

    Concentration levels of 222 Rn and 226 Rn have been analyzed in water samples from boreholes belonging to the drinking water supply system around Toluca, Mexico. The 222 Rn source is the decay of 226 Rn within the solid matrix of the aquifer. The study was performed during the dry and rainy seasons. 222 Rn concentration was determined by the liquid scintillation technique, 226 Rn was determined by gamma spectrometry, the physicochemical parameters and bacteriological analysis were performed by conventional chemical techniques. Solubilized trace elements were determined by Inductively Coupled Plasma - Mass Spectrometry (Icp-Ms). The radon level fluctuations at the boreholes in Toluca city and Almoloya spring indicated differences in the radon content. At borehole Lodos Prietos 2, the temperature and radon level were systematically the highest in comparison with the other boreholes and the spring indicating a contribution of a regional flow to the water of this particular borehole. The result for 226 Rn, the average 222 Rn observed during the sampling period, no correspondence occurs between the radium and the radon content indicating that, radon is not supported by radium, but is incorporated into the water through fissures in the rocks in contact with the water. The radon levels obtained in house faucets which water is supplied by boreholes decrease as a function of the distance from the source borehole to the house. With the chemical composition of each one of the studied boreholes and spring a Piper diagram was draw indicating the kind of water. The boreholes and spring can be classified as bicarbonate calcium/magnesium. Almost no fluctuation on time was observed in the chemical species and trace elements only a slight increase was observed at the end of the rain season. At Almoloya, spring pollution with coliform bacteria and nitrates showed an anthropogenic contribution to the water deterioration probable and fertilizers and detritus. Most of the studied water

  17. Estuarine geochemistry of 224Ra, 226Ra, and 222Rn

    International Nuclear Information System (INIS)

    Elsinger, R.J.

    1982-01-01

    Desorption from river borne sediments is the most likely source of the excess 226 Ra. Laboratory mixing experiments on Pee Dee River sediments show an increase in 226 Ra desorption with increasing salinities with maximum desorption occurring at or above 20 0 /oo salinity. Desorption and diffusion are the sources for 226 Ra in the estuarine systems. In Winyah Bay the 228 Ra/ 226 Ra activity ratio does not change significantly with salinity, averaging around 1.4, indicating desorption as the major source of 228 Ra. In the Yangtze River the 228 Ra/ 226 Ra activity ratio is constant (approx.1.90) until increasing linearly above 16 0 /oo. A diffusive flux from regeneration by 232 Th decay in shelf sediments is the source of the increase. In Delaware Bay 228 Ra increases faster than 226 Ra in the less than or equal to22 0 /oo water, indicating a source in addition to desorption. The increase can be balanced by a 0.33 dpm/cm 2 -year flux over the upper part of the Bay where fine grained sediments predominate. 224 Ra behavior is controlled by its 3.64 day half-life. In Winyah Bay a flux of around 0.4 dpm/cm 2 -day is necessary to support the standing crop of non-desorbed 224 Ra in the water column. In Delaware Bay the nearly constant 224 Ra in concentration over the 2.5 0 /oo to 12 0 /oo salinity range are maintained by regeneration from 228 Th in the turbidity maximum zones and diffusion from bottom sediments. Water leaving on ebb tide from a salt marsh on Delaware Bay had increases in all three radium isotopes ( 224 Ra > 228 Ra > 226 Ra) compared to water coming in on the flood tide. Excess 222 Rn concentrations in a fresh water section of the Pee Dee River show a decreasing downstream gradient. Using these gradients to determine evasion rates, stagnant film thicknesses range from 21μ to 62μ

  18. Toprak Radon (222Rn Gazı Anomalilerinin ARIMA Analizi

    Directory of Open Access Journals (Sweden)

    Miraç KAMIŞLIOĞLU

    2014-12-01

    Full Text Available Özet: Zaman serileri analizi, istatistik, ekonomi, fizik ve mühendislik gibi bilim dallarında geniş uygulama alanına sahiptir. Zaman serisi analizi, değişkenlerin gelecekteki değerlerinin doğru bir şekilde tahmin edilmesi için kullanılan bir yöntemdir. Bu çalışmada, bir deprem öncüsü olarak bilinen toprak radon gazı (222Rn ölçümleri ile bir zaman serisi oluşturulmuştur. Bu veriler kullanılarak, otoregresif süreçler (ARIMA yardımıyla dinamik sistem modellemesi yapılmıştır. ARIMA; zaman serileri analizinde, zaman içerisinde rastgele gerçekleşen bir stokastik (olasılıksal sürecin veya hatalarının modellenmesidir. ARIMA modeli, temelde Box-Jenkins modeline dayanmaktadır. Box-Jenkins modeli, tek değişkenli zaman serilerinin ileriye dönük tahmin ve kontrolünde kullanılan istatistiksel tabanlı bir yöntemdir. Elde edilen sonuçlar, ARIMA modellerinin tahmin konusundaki başarısını göstermektedir. Anahtar kelimeler: Zaman Serileri Analizi, Radon Gazı (222Rn, ARIMA ARIMA Analysis of Soil Radon (222Rn Gas Anomalies Abstract: Time series analysis, has wide applications in statistics, economics, physics and engineering such disciplines. This method used for estimate correctly future values of the variables. In this study, is formed a time series with soil radon gas (222Rn measurements known as a pioneer of an earthquake. Dynamic system modelling was performed with autoregressive (ARIMA modelling process by used these measurements. ARIMA; time series analysis is modelled of the recoverable over time a random stochastic (probabilistic process or its errors. ARIMA model is based on Box-Jenkins model. Box-Jenkins model is a statistically based method which is used forward-looking forecasting and control of univariate time series. The obtained results, ARIMA model is indicating success in predict subject. Key words: Time Series Analysis, Radon Gas (222Rn, ARIMA

  19. Application of spectral decomposition of 222Rn activity concentration signal series measured in Niedźwiedzia Cave to identification of mechanisms responsible for different time-period variations

    International Nuclear Information System (INIS)

    Przylibski, Tadeusz Andrzej; Wyłomańska, Agnieszka; Zimroz, Radosław; Fijałkowska-Lichwa, Lidia

    2015-01-01

    The authors present an application of spectral decomposition of 222 Rn activity concentration signal series as a mathematical tool used for distinguishing processes determining temporal changes of radon concentration in cave air. The authors demonstrate that decomposition of monitored signal such as 222 Rn activity concentration in cave air facilitates characterizing the processes affecting changes in the measured concentration of this gas. Thanks to this, one can better correlate and characterize the influence of various processes on radon behaviour in cave air. Distinguishing and characterising these processes enables the understanding of radon behaviour in cave environment and it may also enable and facilitate using radon as a precursor of geodynamic phenomena in the lithosphere. Thanks to the conducted analyses, the authors confirmed the unquestionable influence of convective air exchange between the cave and the atmosphere on seasonal and short-term (diurnal) changes in 222 Rn activity concentration in cave air. Thanks to the applied methodology of signal analysis and decomposition, the authors also identified a third process affecting 222 Rn activity concentration changes in cave air. This is a deterministic process causing changes in radon concentration, with a distribution different from the Gaussian one. The authors consider these changes to be the effect of turbulent air movements caused by the movement of visitors in caves. This movement is heterogeneous in terms of the number of visitors per group and the number of groups visiting a cave per day and per year. Such a process perfectly elucidates the observed character of the registered changes in 222 Rn activity concentration in one of the decomposed components of the analysed signal. The obtained results encourage further research into precise relationships between the registered 222 Rn activity concentration changes and factors causing them, as well as into using radon as a precursor of geodynamic

  20. Absolute measurement of the activity of 222Rn using a proportional counter

    International Nuclear Information System (INIS)

    Busch, Ingo; Greupner, Heinz; Keyser, Uwe

    2002-01-01

    A measuring set-up comprising a proportional counter of calculable 222 Rn efficiency and quantifiable active volume (δ V 222 Rn efficiency is determined by computer simulation of the measured α-spectra. The procedures necessary for absolute measurements by means of the counter are described, and the suitability of the counter for absolute measurements of the 222 Rn activity is proved by experiments. Thus, a new method for the realization of the unit of activity of 222 Rn is obtained, which is independent of the unit of activity of 226 Ra

  1. Mitigation of {sup 222}Rn induced background in the XENON1T dark matter experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bruenner, Stefan A.

    2017-07-05

    {sup 222}Rn is a major source of background in many rare-event experiments such as the XENON1T dark matter search. The noble gas radon is created by radioactive decay inside all detector materials and emanates into the sensitive liquid xenon target disabling any detector shielding. Subsequent beta-decays of radon progenies are the dominant source of background in the XENON1T experiment. In order to mitigate radon induced background the detector's construction materials have been selected according to dedicated {sup 222}Rn emanation measurements. In the first part of this thesis, we summarize the results of the XENON1T radon screening campaign and present the measurement of the integral radon emanation rate of the fully assembled detector. The development of a radon removal system which continuously purifies the liquid xenon target from the emanated radon is the topic of the second part of this thesis. In order to demonstrate the suitability of cryogenic distillation as a technique to separate radon from xenon, we developed an experimental setup to measure the depletion of radon in xenon boil-off gas after a single distillation step. In the last part of the thesis, we demonstrate the operation of a radon removal system for the XENON100 experiment. For this first test employing a running dark matter detector, we integrated a multiple stage, cryogenic distillation column in the XENON100 gas purification loop. From the evolution of the radon concentration in XENON100, we investigate the distillation column's radon removal capability and discuss the design and application of a radon removal system for XENON1T and the upcoming XENONnT experiment.

  2. Characterization of 222Rn entry into a basement structure surrounded by low permeability soil

    International Nuclear Information System (INIS)

    Ward, D.C.

    1992-01-01

    An experimental facility has been developed to monitor the entry rate and concentration of 222 Rn in two basement type structures surrounded by soil having a permeability on the order of 1- -12 m 2 . A data acquisition system recorded environmental conditions outside and inside the structures, including basement air exchange rates, every 15 min. Indoor 222 Rn concentrations ranged from 400 to 1400 Bq m -3 . The observed 222 Rn entry rate is highly variable and has two primary components; a constant input rate caused by diffusion of 222 Rn through the concrete walls and floor, and a variable rate that depends upon indoor-soil pressure differentials of only a few pascals. Pressure differentials are dependent upon wind speed and wind direction. Stack effect was not significant. During a two week period, with relatively calm winds, diffusion through the concrete walls and floor plus the floor-wall joint accounted for more than 80% of the total 222 Rn entry

  3. Performance improvements on passive activated charcoal 222Rn samplers

    International Nuclear Information System (INIS)

    Wei Suxia

    1996-01-01

    Improvements have been made on passive activated charcoal 222 Rn samplers with sintered metal filters. Based on the samplers of good adaptability to temperature and humidity developed before, better charcoal was selected to further improve their performance in radon absorption ability and moisture-resistance. And charcoal quantity in samplers was strictly controlled. The integration time constant of the improved samplers was about 4.3 days. As the sampler was combined with gamma spectrometer to measure radon concentration, the calibration factor was 0.518 min -1 ·Bq -1 ·m 3 for samplers of 7 days exposure time, and the minimum detectable concentration 0.28 Bq·m -3 if counting time for both background and sample is 1000 minutes. The improved samplers are suited to accurately determine the indoor and outdoor average radon concentration under conditions of great variation in temperature and humidity

  4. A source of ground water 222Rn around Tachikawa fault

    International Nuclear Information System (INIS)

    Saito, Masaaki; Takata, Sigeru

    1994-01-01

    Radon ( 222 Rn) concentration in ground water was characteristically high on the south-western zone divided by the Tachikawa fault, Tokyo. (1) The concentration did not increase with depth, and alluvium is thick on the zone. The source of radon was not considered as the updraft from base rock through the fault. Comparing the south-western zone with its surrounding zone, the followings were found. (2) The distribution of tritium concentration was supported that water had easily permeated into ground on the zone. (3) As the zone is located beside the Tama River and its alluvial fan center, the river water had likely affected. The source of radon on the zone would be 226 Ra in the aquifer soil. It can be presumed that the water of the Tama River had permeated into ground on the zone and had accumulated 226 Ra. (author)

  5. Dose by {sup 222} Rn in houses of the Chihuahua city; Dosis por {sup 222} Rn en casas-habitacion de la ciudad de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Colmenero S, L.H.; Talamantes F, C. [ITCH II, Ave. de las Industrias 11101, Chihuahua (Mexico); Villalba, M.L. [UACH, Facultad de Ingenieria, Chihuahua (Mexico); Dobson, P.F. [Laboratorio Nacional Lawrence Berkeley, California (United States); Ortalejo M, B. [UACH, Facultad de Enfermeria y Nutriologia, Chihuahua (Mexico)]. e-mail: luis.colmenero@cimav.edu.mx

    2007-07-01

    selected. The quantification of the radon was made every 10 minutes during three continuous days, with the AlphaGUARD Pro2000 equipment that also measures atmospheric parameters. The obtained data were analyzed with the Genitron software and was analyzed the variation of the radon concentration with the atmospheric parameters and a hours in that the person is in the room. Finally they were carried out the dosimetry calculations due to the radon in air, adding it with the dose received by floor and water due to the natural radionuclides. As it was expected, the city of Chihuahua when being on an uranifer floor and the materials of construction of housings are elaborated starting from this floor, high concentrations were presented of {sup 222}Rn. The third part of the houses had a bigger average to the 148 Bq/m{sup 3} in air, with values average for the whole day of up to 276 Bq/m{sup 3}, as well as maxima values near to 900 Bq/m{sup 3}. When making the calculation of the concentration for the night and dawn that it is when the one inhabitant remains in the room and that to avoid the cold he closes doors and windows, the radon concentration ascended until values of 305 Bq/m{sup 3}. The calculation of the dosimetry was in high values for the radon of until 3.2 mSv/year that adding to the floor values (0.63 mSv/year) and water (0.016 mSv/year) it gives a value of 3.85 mSv/year, considering these values very superior to those registered in other cities of the country reported in the bibliography or by the CNSNS. (Author)

  6. 222Rn and decay products in outdoor and indoor environments

    International Nuclear Information System (INIS)

    Samuelsson, C.

    1984-05-01

    Radon-222 (radon) and radon daughter (RnD) measurement methodologies are analysed from both theoretical and experimental points of view. It is shown that exhalation from enclosed porous materials can be described in terms of the time-dependent diffusion theory. Deficiencies in the established accumulator method of radon exhalation measurement are shown. By the existing methods, the true free exhalation rate of thin samples may be underestimated by a factor of (1+α- 1 ), in radon-tight accumulators (α is the outer to inner volume ratio of the sample). The term back-diffusion is clarified and shown applicable to steady-state conditions only. The wire-screen technique is utilized to separate aerosol-attached and unattached RnD in a 3 m 3 radon cell. The effect of air-filtration on the RnDs is expressed as individual activity concentrations as well as in terms of effective dose equivalent rate, H. H has been reduced by a factor between 1.3 and 2.5 for the small-sized areosol particles used (surface area median less than 100 nm), at the filtration rate constant 5 h- 1 . The exact reduction value is dependent on initial aerosol load, type of filter, and dose model (Jacobi-Eisfeld and James-Birchall in this investigation). The concentration of radon and Pb-210 in the Arctic summer air averaged 75+-21 and 0.075+-0.028 mBq m- 3 , during the Swedish Ymer-80 expedition. It is shown that steadystate equilibrium models are unsuitable for estimation of the mean aerosol residence time in ocean air. A good qualitative agreement between radon-levels and the time since the air mass left larger land areas was found. The radon-222 and long-lived daughter (Pb-210, Po-210) measurements are insensitive to ship- and local contaminations. (author)

  7. Measurements of octupole collectivity in $^{220,222}$Rn and $^{222,224}$Ra using Coulomb excitation

    CERN Multimedia

    Kruecken, R; Larsen, A; Hurst, A M; Voulot, D; Grahn, T; Clement, E; Wadsworth, R; Gernhaeuser, R A; Siem, S; Huyse, M L; Iwanicki, J S

    2008-01-01

    We propose to exploit the unique capability of ISOLDE to provide post-accelerated $^{220,222}$Rn and $^{222,224}$Ra ion beams from the REX facility to enable the Coulomb excitation of the first 3$^{-}$ states in these nuclei. By measuring the $\\gamma$-ray yields of the E1 decays from the 3$^{-}$ state using the MINIBALL array we can obtain the transition matrix elements. This will give quantitative information about octupole correlations in these nuclei. We require 22 shifts to fulfil the aims of the experiment.

  8. Relationship between 222Rn concentration in soil water and degree of saturation

    International Nuclear Information System (INIS)

    Hamada, Hiromasa; Komae, Takami

    1996-01-01

    The object of the researches an analyzing downward flow to groundwater using 222 Rn concentration in water as an indicator has been saturated flow. However, when groundwater table is low, downward flow from surface is unsaturated flow. In this paper, the authors represented the relationship between 222 Rn concentration in soil water and degree of saturation, and measured the vertical distributions of 222 Rn concentrations in groundwater and 222 Rn concentration in water table in the fields. As the results, it was found that 222 Rn concentrations in the vicinity of groundwater table decreased by unsaturated downward flow. Moreover, from the variation of 222 Rn concentrations in groundwater table, it was possible to show the occurrence of the unsaturated downward flow by paddy fields irrigation, i.e., the downward flow of the soil water pushed out by irrigation water, the unsaturated percolation in the irrigation period, and the redistribution of the soil water after the release of ponding water. The degree of saturation in downward flow was calculated to be about 50% from 222 Rn concentrations in the irrigation period and in the non-irrigation period. It was deduced that the value was within reasonable range considering the difference of the hydraulic conductivities between of the upper layer and of the lower layer. These results proved that the relationship between 222 Rn concentrations in soil water and degree of saturation represented by the authors was reasonable and that the analytical method using 222 Rn concentrations in groundwater table as an indicator was useful 10 analyze the actual stale of unsaturated downward flow. (author)

  9. Online {sup 222}Rn removal by cryogenic distillation in the XENON100 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Messina, M.; Plante, G.; Rizzo, A.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Orrigo, S.E.A.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L.; Franco, D.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wei, Y.; Wulf, J. [University of Zurich, Physik-Institut, Zurich (Switzerland); Bauermeister, B. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Stockholm University, AlbaNova, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Undagoitia, T.M.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Gallo Rosso, A.; Molinario, A. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; Duchovni, E.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. v. [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Calven, J.; Conrad, J.; Ferella, A.D.; Pelssers, B. [Stockholm University, AlbaNova, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Cervantes, M.; Lang, R.F.; Masson, D.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Le Calloch, M.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [Universite de Nantes, SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (France); Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN, Bologna (Italy); Fei, J.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Grandi, L.; Saldanha, R.; Shockley, E.; Upole, N. [University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Lindemann, S. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Meng, Y.; Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Miguez, B.; Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Lavina, L.S. [LPNHE, Universite Pierre et Marie Curie, Universite Paris Diderot, CNRS/IN2P3, Paris (France); Tunnell, C. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Cristescu, I. [Karlsruhe Institute of Technology, Tritium Laboratory Karlsruhe, Eggenstein-Leopoldshafen (Germany); Collaboration: XENON Collaboration

    2017-06-15

    We describe the purification of xenon from traces of the radioactive noble gas radon using a cryogenic distillation column. The distillation column was integrated into the gas purification loop of the XENON100 detector for online radon removal. This enabled us to significantly reduce the constant {sup 222}Rn background originating from radon emanation. After inserting an auxiliary {sup 222}Rn emanation source in the gas loop, we determined a radon reduction factor of R > 27 (95% C.L.) for the distillation column by monitoring the {sup 222}Rn activity concentration inside the XENON100 detector. (orig.)

  10. Mapping of 222Rn and 4He in soil gas over a karstic limestone-granite boundary: correlation of high indoor 222Rn with zones of enhanced permeability

    International Nuclear Information System (INIS)

    O'Connor, P.J.; Gallagher, V.; Van den Boom, G.

    1992-01-01

    Recent indoor radon reconnaissance surveys in Ireland have identified buildings with high radon concentrations (up to 1700 Bq.m -3 ) overlying Carboniferous karstic limestone sequences in the western part of the country. A detailed investigation of indoor 222 Rn and soil gas 222 Rn and 4 He concentrations has been carried out over a karstic limestone-uraniferous granite boundary in County Galway. High indoor 222 Rn concentrations occur in dwellings over both lithologies. Radon migratory routes in bedrock and overburden appear to be controlled by zones of enhanced permeability, e.g. fractures, faults, etc. which are defined by linear arrays of elevated 4 He soil gas values. While the ultimate source of radon remains conjectural, the greatly enhanced permeability of karstified limestone is thought to be of fundamental importance in providing a means of rapid radon transport into overlying soils and buildings. (author)

  11. {sup 222} Rn determination and physicochemical characteristic and biological in aquifers in the Toluca Valley; Determinacion de {sup 222} Rn y caracteristicas fisicoquimicas y biologicas en acuiferos del Valle de Toluca

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez A, A

    1998-10-01

    Concentration levels of {sup 222} Rn and {sup 226} Rn have been analyzed in water samples from boreholes belonging to the drinking water supply system around Toluca, Mexico. The {sup 222} Rn source is the decay of {sup 226} Rn within the solid matrix of the aquifer. The study was performed during the dry and rainy seasons. {sup 222} Rn concentration was determined by the liquid scintillation technique, {sup 226} Rn was determined by gamma spectrometry, the physicochemical parameters and bacteriological analysis were performed by conventional chemical techniques. Solubilized trace elements were determined by Inductively Coupled Plasma - Mass Spectrometry (Icp-Ms). The radon level fluctuations at the boreholes in Toluca city and Almoloya spring indicated differences in the radon content. At borehole Lodos Prietos 2, the temperature and radon level were systematically the highest in comparison with the other boreholes and the spring indicating a contribution of a regional flow to the water of this particular borehole. The result for {sup 226} Rn, the average {sup 222} Rn observed during the sampling period, no correspondence occurs between the radium and the radon content indicating that, radon is not supported by radium, but is incorporated into the water through fissures in the rocks in contact with the water. The radon levels obtained in house faucets which water is supplied by boreholes decrease as a function of the distance from the source borehole to the house. With the chemical composition of each one of the studied boreholes and spring a Piper diagram was draw indicating the kind of water. The boreholes and spring can be classified as bicarbonate calcium/magnesium. Almost no fluctuation on time was observed in the chemical species and trace elements only a slight increase was observed at the end of the rain season. At Almoloya, spring pollution with coliform bacteria and nitrates showed an anthropogenic contribution to the water deterioration probable and

  12. Inhalation exposures due to radon and thoron ((222)Rn and (220)Rn): Do they differ in high and normal background radiation areas in India?

    Science.gov (United States)

    Mishra, Rosaline; Sapra, B K; Prajith, R; Rout, R P; Jalaluddin, S; Mayya, Y S

    2015-09-01

    In India, High Background Radiation Areas (HBRAs) due to enhanced levels of naturally occurring radionuclides in soil (thorium and, to a lesser extent, uranium), are located along some parts of the coastal tracts viz. the coastal belt of Kerala, Tamilnadu and Odisha. It is conjectured that these deposits will result in higher emissions of radon isotopes ((222)Rn and (220)Rn) and their daughter products as compared to Normal Background Radiation Areas (NBRAs). While the annual external dose rates contributed by gamma radiations in these areas are about 5-10 times higher, the extent of increase in the inhalation dose rates attributable to (222)Rn and (220)Rn and their decay products is not well quantified. Towards this, systematic indoor surveys were conducted wherein simultaneous measurements of time integrated (222)Rn and (220)Rn gas and their decay product concentrations was carried out in around 800 houses in the HBRAs of Kerala and Odisha to estimate the inhalation doses. All gas measurements were carried out using pin-hole cup dosimeters while the progeny measurements were with samplers and systems based on the Direct radon/thoron Progeny sensors (DRPS/DTPS). To corroborate these passive measurements of decay products concentrations, active sampling was also carried out in a few houses. The results of the surveys provide a strong evidence to conclude that the inhalation doses due to (222)Rn and (220)Rn gas and their decay products in these HBRAs are in the same range as observed in the NBRAs in India. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Measurements of 222Rn and 226Ra Levels in environmental samples by using liquid scintillation counter

    International Nuclear Information System (INIS)

    Moustafa, A.S.

    2004-01-01

    The advantageous of liquid scintillation counting technique for 6 Ra determination compared with other methods are the high counting efficiency and the easier sample preparation, with no need for sample pre-concentration. In this work, liquid scintillation counting system was used to measure 222 Rn and 226 Ra levels in environmental samples. The liquid scintillation cocktail was prepared in the laboratory and was found efficient for measuring 222 Rn. Soil, sediment and TENORM samples were dried, grind, sieved and added to hydrochloric acid, in a standard scintillation vial, preloaded with the liquid scintillation cocktail. By measuring 222 Rn levels in the prepared vials, at different intervals of time after preparation, 222 Rn and 226 Ra levels were determined

  14. Potable water as a source of airborne 222Rn in US dwellings: a review and assessment

    International Nuclear Information System (INIS)

    Nazaroff, W.W.; Doyle, S.M.; Nero, A.V.; Sextro, R.G.

    1987-01-01

    Using a long-term-average, single-cell model and available data for U.S. housing, the concentration of 222 Rn in indoor air due to the use of potable water is assessed. The ratio of the airborne 222 Rn concentration to the concentration in water is represented by a lognormal distribution with geometric mean and geometric standard deviation of 0.65 X 10(-4) and 2.88, respectively, in fair agreement with the previously reported results of direct measurements of the ratio in 13 houses. By combining this result with data on 222 Rn concentrations in U.S. water supplies, potable water is estimated to contribute an average of 24, 1.3, and 0.1 Bq m-3 to the airborne 222 Rn concentration in residences served by private wells, public ground water, and surface water supplies, respectively

  15. Indoor 222Rn measurements in the region of Beijing, People's Republic of China

    International Nuclear Information System (INIS)

    Ren, T.S.; Lin, L.Q.; Chen, Z.P.; Li, G.Y.; Chen, A.M.

    1987-01-01

    Passive integrating activated C detectors were used to study the regional distribution and temporal variation of 222 Rn in indoor air in dwellings in the Beijing region. Measurements were made in 537 dwellings, which were either detached houses or multi-family apartments. The city-wide study was completed in 1985. The distributions are approximately log-normal with 90% of the dwellings having 222 Rn levels less than 60 Bq m-3. The weighted average 222 Rn concentration has been found to be 22.4 Bq m-3. Averages for detached houses and multi-family dwellings are 25.9 and 15.2 Bq m-3, respectively. Assuming an equilibrium factor of 0.5 and an occupancy factor of 0.8, the average equilibrium equivalent concentration of 222 Rn progeny is 11.2 Bq m-3 and the annual average effective dose equivalent is 1.1 mSv

  16. Primary measuring of equipment factor of 222Rn/220Rn indoor

    International Nuclear Information System (INIS)

    Liu Yanyang; Liu Fudong; Wang Chunhong; Sheng Mingwei

    2010-01-01

    The activity concentration of 222 Rn, 220 Rn and their progenies of certain working places and dwellings in Baotou city were measured simultaneously. Based on these results, the equipment factor of 222 Rn is 0.35 for working places and 0.43 for dwellings, while equipment factor of 220 Rn measured at 20 cm distance from wall is 0.030 for both working places and dwellings. Preliminary results show that the temporal change of 220 Rn equilibrium equivalent concentration is same as 222 Rn which is high in midnight and low in afternoon,and significant difference between instant and accumulated measure result of 222 Rn, 220 Rn activity concentration is found, with the factor of 2.1 and 1.7. (authors)

  17. Seasonal variations of CO2 and 222Rn in a mediterranean sinkhole - spring (Causse d’Aumelas, SE France

    Directory of Open Access Journals (Sweden)

    Batiot-Guilhe Christelle

    2007-01-01

    Full Text Available Carbon dioxide and 222Rn monitoring of the atmosphere of a Mediterranean sink hole - spring (SE France during two hydrological cycles (from September 2004 to September 2006 showed seasonal variations with very high concentrations during summer (greater than 6% and 20 000 Bq/m3, respectively. Gas dynamics in caves often show seasonal variations.Meteorological parameters (barometric pressure and temperature mainly, cave geometry and fracture networks control exchanges between the cavity and outside atmosphere. Carbon dioxide and 222Rn may have different sources (atmosphere, soil, bedrock, deep gas diffusion, in situ oxidation of organic matter and, in some caves, the key role of swift underground streams.For a CO2 origin, 13C measurements on water and gas samples taken into the cavity suggest a superficial origin. Radon-222 appears to be locally produced and transported by biogenic CO2. Further investigations will be carried out in order to study the relationship of gas-level variations with barometric pressure variations and piezometric level fluctuations within the aquifer.

  18. Measurements of 222Rn flux with charcoal coanisters

    International Nuclear Information System (INIS)

    Countess, R.J.

    1977-01-01

    Methods used to measure the 222 Rn flux from the ground are discussed. The most common method is the direct accumulation of radon in a closed container resting on the soil surface. An aliquot of the air is transferred from the accumulator either to an ionization chamber or to an alpha scintillation flask for radon analysis. An alternate method consists of entraining the radon emanating from a small area of the ground in an airstream moving in a closed system through a charcoal trap or cold trap. At the end of the sampling period, the trap is sealed and returned to the laboratory where the radon is transferred into an evacuated scintillation flask for analysis. Still another method consists of adsorbing radon in a layer of granular, activated charcoal spread directly on the ground. For analysis, the charcoal is bagged and the 0.61-MeV gamma activity of 214 Bi (RaC) is measured in a gamma spectrometer. These last two methods have the disadvantage that some radon may be lost in transfer prior to analysis. In an improved method, which is simpler than the preceding methods and eliminates this transfer problem, a modified U.S. Army M11 gas mask canister containing activated charcoal is placed directly in contact with the emanating surface and after an exposure period from several hours to several days, depending on the anticipated flux density, the canister is removed from the surface and counted directly in a gamma spectrometer. In addition to precluding losses in sample transfer, a major advantage is that numerous measurements can be made inexpensively due to the low cost of the canisters and their ease of deployment and recovery

  19. Radon gas inside historical buildings in the city of Cordoba; Gas {sup 222}Rn en construcciones historicas de la ciudad de Cordoba

    Energy Technology Data Exchange (ETDEWEB)

    Perez, R; Germanier, A; Rubio, M [CEPROCOR, Cordoba (Argentina); Sbarato, D; Zappino, R [Observatorio Ambiental de la Municipalidad de Cordoba, Cordoba (Argentina)

    1998-07-01

    Full text: In this work measurements of the Radon ({sup 222}Rn) concentration in the inside of historical buildings which date back to the end of the 17th and the beginning of the 18th Centuries have been carried out in the city of Cordoba (Argentina). Meteorological factors such as room temperature and atmospheric pressure have not shown to affect, to a great extent, the results obtained. By comparing the concentration of {sup 222}Rn in environments at different levels we inferred that the soil underlying the buildings does not represent an important source of {sup 222}Rn. The main occurrence of the element was found in room walls, which shows that local building materials are an important source of {sup 222}Rn. Among the materials used in these buildings are granitic rocks, and to a lesser extent, lime, sand and marble. The {sup 222}Rn concentrations recorded in some of the rooms surveyed reach values which are close to the minimum intervene level set by international standards in 4pCi/l. The study of the effects of ventilation in the concentration of {sup 222}Rn allows us to conclude that its values decrease to accepted levels by means of a natural and efficient ventilation of the rooms. (author) [Spanish] Texto completo: En este trabajo se han realizado mediciones de la concentracion de radon (radon 222) en el interior de edificios de la ciudad de Cordoba que datan de finales del siglo XVII y comienzos del siglo XVIII. Las concentraciones de radon 222 se determinaron con un detector pasivo Radon Monitor 05-418, marca Victoreen. El mismo consta de una camara de difusion electrostatica y un detector de estado solido (Si) de juntura difundida. No se observo, en los resultados obtenidos, influencias causadas por factores meteorologicos como la temperatura ambiente y la presion atmosferica. Por comparacion de la concentracion de radon 222 en ambientes ubicados en distintas plantas se dedujo que el suelo subyacente bajo los edificios representa una fuente secundaria

  20. Determination of 222Rn in water by absorption in polydimethylsiloxane mixed with activated carbon and gamma-ray spectrometry: An example application in the radon budget of Paterno submerged sinkhole (Central Italy)

    International Nuclear Information System (INIS)

    Voltaggio, M.; Spadoni, M.

    2013-01-01

    Highlights: ► Polydimethylsiloxane and Activated Carbon were used as passive gas accumulator. ► Water-impermeable properties of PDMS combine with adsorptive properties of AC. ► PDMS–AC accumulators can be used to study 222 Rn in water. ► Measured 222 Rn specific activity in PDMS–AC matches the theoretical results. ► We used PDMS–AC in the radon budget of a submerged sinkhole. - Abstract: Passive gas accumulators made of polydimethylsiloxane (PDMS) mixed with activated C (AC) were studied to measure their efficiency for sampling Rn in water. In this composite the water-impermeable properties of PDMS act synergistically with adsorptive properties of AC, even when the accumulators are immersed in water for many days. A series of tests where cylindrical shaped PDMS–AC disks were exposed to different 222 Rn-enriched waters showed that measured 222 Rn specific activity matches the theoretical results coming from the equation that describes the process of internal diffusion integrated with the Rn decay term. The linear relationship between 222 Rn in water and the accumulation process in PDMS–AC, the influence of temperature and the different sensitivity of the composite and its components were also studied and discussed. The high Rn volumetric enrichment factor in PDMS–AC disks respect to water resulted in about 206: 1, so lowering detection limits for 222 Rn in water to 20 Bq m −3 when the total activity of Rn progeny in disks is measured by high resolution gamma-ray spectrometry. The use of PDMS–AC accumulators was tested at the Paterno submerged sinkhole, in central Italy. This study allowed the production of a detailed synchronous vertical profile of the Rn content in the middle of the lake and to define the Rn balance by assessing the discharge rate of submerged springs and the average residence time of the lake water

  1. HARAD, Decay Isotope Concentration from Atmospheric Noble-Gas Release

    International Nuclear Information System (INIS)

    Moore, R.E.

    1986-01-01

    1 - Description of problem or function: HARAD calculates concentrations of radioactive daughters in air following the atmospheric release of a parent radionuclide for a variety of release heights and meteorological conditions. It can be applied most profitably to the assessment of doses to man from the noble gases such as Rn-222, Rn-220, and Xe and Kr isotopes. These gases can produce significant quantities of short-lived particulate daughters in an airborne plume, which are the major contributors to dose. The simultaneous processes of radioactive decay, buildup and environmental loss due to wet and dry deposition on ground surfaces are calculated for a daughter chain in an airborne plume as it is dispersed downwind from a point of release of a parent. 2 - Method of solution: The code evaluates the analytic solution to the set of coupled first order differential equations describing time variation of the concentration of a chain of radionuclides. The analytic solutions assume that the coefficient describing the fractional rate of dry deposition is constant with time. To account for the variation the time coordinate is automatically divided into intervals and a set of average values are used. 3 - Restrictions on the complexity of the problem: - The maximum length of decay chain is 10 nuclides; calculations can be made at a maximum of 24 downwind distances

  2. 222Rn levels in Kingsville, Texas, and vicinity near an in situ uranium mine

    International Nuclear Information System (INIS)

    McGehee, T.L.; Martino, M.R.; Harr, T.L.; Samudio, A.

    1994-01-01

    An investigation of the 222 Rn levels in ground water, soils, and indoor air has disclosed two 222 Rn ground-water anomalies in the Kingsville, Texas, area from uranium-enriched sandstones of the Evangeline aquifer. Indoor air 222 Rn levels were measured in summer 1991 (from undetectable to 3.2 pCi/l) and winter 1991-1992 (0.01 to 3.98 pCi/l) to determine seasonal extremes and risk to the public. Soil 222 Rn concentration maps ranging from undetectable to 75.4 pCi/l correlate to the low levels found in homes. Results of this study are based on analyses of 218 water samples, 52 in situ soil samples, and 104 indoor air samples. Water samples were injected into a scintillation mix (EPA/EERF-Manual-78-1) and analyzed by liquid scintillation techniques. Indoor air and soil samples were collected using passive charcoal canisters and analyzed by gamma-ray detection techniques (EPA 520/5-87-005). One ground-water 222 Rn anomaly lies near the permitted boundary of a large uranium deposit that is being mined. Private wells near the ore body yielded, 1,023 to 23,256 pCi/l at the well head. A second anomaly is located 2.5 mi (4 km) north of the uranium ore body near Naval Air Station, Kingsville. Private water wells in this area yielded 442 to 1,950 pCi/l 222 Rn at the well head. The radon anomalies are related to subsurface mineralization, which is one of the known natural geologic hazards of this area. Indoor air 222 Rn levels are well below the U.S. Environmental Protection Agency (US/EPA) action limit of 4 pCi/l. However, the high levels of 222 RN in ground water should be mitigated before entry into the home environment. High 222 Rn levels in ground water were reduced to background levels in household waters by use of a pre-introduction large-capacity holding tank

  3. Extreme levels of 222Rn and U in a private water supply

    International Nuclear Information System (INIS)

    Lowry, J.D.; Hoxie, D.C.; Moreau, E.

    1987-01-01

    In 1985, the Maine Department of Human Services discovered a private water supply in Leeds, ME, that contains over 40,700 BqL -1 (1.1 x 10 +6 pCil -1 ) of 222 Rn on average, and ranges between 13,300 and 59,200 Bql -1 . The well water also contains a gross alpha concentration of approximately 10.0 BqL -1 (270 pCiL -1 ), of which more than 95 percent is U (403 ugL -1 ). The ratio of 234 U to 238 U averages 1.17, which compares closely to the sea water at 1.14. The Ra content comprises less than 2 percent of the gross alpha. The levels of 222 Rn and U are considered to be extremely high, with the 222 Rn being the highest known level the authors are aware of for a drinking water supply. This area of Maine has geologic features characteristic of those shown by others to have a high potential for elevated levels of 222 Rn and other radioisotopes. The purpose of this paper is to update the information presented previously about this site, in particular to the ramifications on treatment alternatives associated with the presence of both 222 Rn and U in a water supply

  4. 222Rn in private well water in the vicinity of uranium mines over ten years

    International Nuclear Information System (INIS)

    Yunoki, Eiji; Kataoka, Toshio; Michihiro, Kenshu; Sugiyama, Hirokazu; Shimizu, Mitsuo; Mori, Tadashige

    1994-01-01

    There are many small uranium mines of the sedimentary type in Kamisaibara, Okayama Prefecture, Japan. As inhabitants in Kamisaibara consume water from privately-dug wells, it is important to investigate distributions of 222 Rn in privately-dug well water in the vicinity of the mines. The determination of 222 Rn in well water was carried out from April 1980 to October 1990. Though small in area (16 km 2 ), each well water has its own characteristic activity concentrations of 222 Rn. The activity concentrations of 222 Rn are almost constant for each specific well over a long period (about 10 years). In general, the correlation coefficients for several sampling points are small. As Akawase and Tennoh are situated in the same rock type, the correlation coefficient is the highest value in this area. The estimated dose equivalent for the human stomach is approximately 0.4-54 μSv/year. The type of distribution of 222 Rn in privately-dug well water is log normal. (author)

  5. Parameters of calibration of the measurement system of 222 Rn based in LR-115

    International Nuclear Information System (INIS)

    Garcia, M.L.; Mireles, F.; Quirino, L.; Davila, I.; Lugo, F.; Pinedo, J.L.; Chavez, A.

    2003-01-01

    Since the SSNTD technique (Solid State Nuclear Track Detection) it was discovered it has been used as passive method for the detection of subnuclear particles in great variety of fields of the science. The use of the technique in measurements of 222 Rn in air have already been established implying better methodologies in the exhibition to the environment until their engraving and reading processes. The SSNTD technique is since a method by comparison since the material it can be used a single time, therefore it requires of calibration in one controlled radon atmosphere, using gauged standards. The objective of this work is to show the calibration of the devices used as radon monitors based on SSNTD. The material used as SSNTD is LR-115 Il. The standardization of the parameters used in the exhibition to radon in air, engraving and reading process, its are based on the response of the LR-115 Il, the one arrangement of the device, engraving speed and mainly the calibration factor. They are considered two types of monitors: Open camera and Closed camera, the difference among the calibration factors of both cameras is the percentage of the descendants of radon in the open camera. The standardized parameters are operation voltage of the counting system; temperature, time and concentration of the engraving solution; and thickness. (Author)

  6. Measurement of activity concentration of 222Rn in ground waters drawn from two wells drilled in the Amparo Complex metamorphic rocks, municipio de Amparo, SP

    International Nuclear Information System (INIS)

    Oliveira, Igor Jose Chaves de

    2008-01-01

    A sampling system was assembled for field 222 Rn activity concentration measurements in ground waters. The system consists of a sampling flask that prevents the contact between the water sample and the atmosphere and a closed line for radon extraction from water. The system, its operation and calibration, are described in full detail, as well as, the conversion of the measured alpha counting rates in activity concentrations. The assembled system was used in 222 Rn activity concentrations measurements in ground waters drawn from two wells drilled in the Amparo Complex metamorphic rocks. The wells are located at the urban area of the city of Amparo and are exploited for public use water. One well, named Vale Verde, is 56 meters deep and crosses 18 meters of soil, 26 meters of quartz rich gneiss and 12 meters of biotite-gneiss. The other well, named Seabra, is 117 meters deep, crosses 28 meters of soil and weathered rocks and ends in granite-gneiss. The mean activity concentrations for the year long observation were (377 +- 25) Bq/dm 3 , for Seabra well, and (1282 +- 57) Bq/dm3, for the Vale Verde well. The 222 Rn activity concentrations fall in the activity concentration range reported in the literature for similar geology areas and are larger than the concentrations found neighboring areas of the same metamorphic Complex. The seasonal activity concentration variations seem to correlate with rain fall variations in the study area. (author)

  7. Direct determination of 222Rn gas using the electret to remove daughters at formation

    International Nuclear Information System (INIS)

    Harley, N.H.

    1981-01-01

    Five compact, portable, continuous 222 Rn monitors have been constructed inhouse. Printed data can be obtained from intervals ranging from 10 minutes to 990 minutes. One hour count interval provides a lower limit of detection of 0.03 pCi 222 Rn/l -1 which is sufficient for measurement of any environmental level encountered. Calibration of the units was accomplished in the EML radon calibration room and the typical calibration factor is 165 counts per hour per pCi 222 Rn/l. The units are now being field tested. Two indoor/outdoor pairs are located in a single family dwelling and in a high rise apartment. One unit is being used for special studies

  8. Occurrence of 222Rn and progeny in natural gas processing plants in western Canada

    International Nuclear Information System (INIS)

    Drummond, I.; Boucher, P.; Bradford, B.; Evans, H.; McLean, J.; Reczek, E.; Thunem, H.

    1990-01-01

    In Western Canada, there are many plants that process natural gas to remove impurities (CO 2 , H 2 S, H 2 O) and recover natural gas liquids (propane, butane, etc.). Trace quantities of 222 Rn present in the inlet stream are concentrated in streams rich with propane. Potential hazards to plant operators include direct inhalation of 222 Rn and progeny; exposure to gamma radiation from short-lived progeny deposited inside equipment; or inhalation of 210 Pb when contaminated equipment is opened for repair. Twenty-four plants operated by seven companies cooperated to assess these potential hazards. The findings indicate a substantial flux of 222 Rn and progeny passing through the plants, but little accumulation of radionuclides. In no case was there evidence of significant exposure of plant operators or maintenance personnel to ionizing radiation. Further investigation of pipeline operations, and chemical operations using natural gas liquids as feed stock, is recommended

  9. An application of 222Rn alpha particle's tracks to uranium exploration

    International Nuclear Information System (INIS)

    Aguilar H, F.

    1981-01-01

    The uranium exploration method is based on the register of 222 Rn alpha particles; 222 Rn gas is generated in the chain 238 U desintegration. The detection of alpha particles was performed with cellulose nitrate films (NTC), located in a grid at the region in study. The alpha particles produce latent tracks in the NTC films; these tracks may be enlarged by chemical etching and are observed with an ordinary optic microscope, ninety seven NTC films were used, these were distributed in an area of approximately seventeen square kilometers, located in the municipalities of Granados and Huasabas in Sonora Mexico, the detectors remain in the ground for a thirty days mean period. The results obtained show an area with high 222 Rn concentration, this can be related with an underground uranium ore deposit. The more important conclusion is that the results obtained in this work can be used as preliminary results for other prospection methods in this particular area. (author)

  10. The correlation between exhalation from rocks and indoor concentration of 222Rn in the Sydney area

    International Nuclear Information System (INIS)

    MCKenzie, D.R.; Lenzen, M.; Solomon, S.B.

    2001-01-01

    The results of a survey of indoor 222 Rn concentrations of 350 dwellings in the Sydney area are combined with measurements of 222 Rn exhalation rates of principal rock types in the survey area. A linear regression is predicted which yields a positive regression coefficient of b=2.4±0.3, a constant of a=3.4±0.5, and a correlation coefficient of R 2 =0.15. This correlation was found to be highly significant by using three different statistical tests. The ratio of the indoor 222 Rn concentrations in dwellings built on the two dominant rock types, the Wianamatta Shale and the Hawkesbury Sandstone, was found to be about 1.6. Copyright (2001) Australasian Radiation Protection Society Inc

  11. 222Rn Determination In Drinking Waters - RAD7 And LSC Technique Comparison

    International Nuclear Information System (INIS)

    Todorovic, N.; Stojkovic, I.; Nikolov, J.; Tenjovic, B.

    2015-01-01

    A procedure for the determination of 222Rn in environmental water samples using liquid scintillation counting (LSC) was applied and optimized. For radon determination in drinking water from groundwater and surface water sources by LSC, the EPA Method 913.0 was used. A minimum detectable activity of 0.029 Bq L-1 in a 20 mL glass vial (10 mL water sample mixed with 10 mL of liquid scintillation cocktail) has been achieved during 300 minutes of measurement time. The procedure was compared with RAD7 radon detector measurements. Factors that affect the measurement accuracy and precision of RAD7 radon detector are the sampling technique, sample concentration, sample size, counting time, temperature, relative humidity and background effects. The minimal detectable activity (MDA) for RAD7 technique was found to be 0.1 Bq/L. From obtained results of 222Rn measurements in 15 water samples with different 222Rn activities, correlation between the two techniques applied for measurements of 222Rn in water samples (A less than 400 Bq/L) was determined. There is reasonable agreement (within statistical uncertainties) between the various techniques in most cases, while disagreements most likely come from systematic uncertainties associated with sampling procedures. Discrepancy in determined activities between the two techniques becomes more evident with increased 222Rn activities in water. LSC technique gives in general higher activity concentrations for about 30 percent than RAD7 spectrometer. The interpretation of shown results could be that RAD7 is not properly calibrated for higher activities, since USA reference level of 222Rn concentrations in water is only 11.1 Bq/L (US EPA, Proposed Radon in Drinking Water Regulation). (author).

  12. Concentrations of 222Rn in well and tap waters of North-Eastern Attiki (Central Greece)

    International Nuclear Information System (INIS)

    Kritidis, Panaiotis; Angelou, Panaiotis.

    1984-07-01

    An alpha-scintillation system for determination of low 222 Rn concentrations in water is described. The use of vacuum sampling, the avoidance of sample transfer and the corrections applied result in low systematical errors. The method has been used for a preliminary investigation of 222 Rn concentrations in well waters of NE Attiki, where values between 4 and 345 pCi/1 have been observed. The additional annual effective dose equivalent due to the systematic domestic use of water with the highest radon concentration measured is estimated not to exceed 5 mrem. (author)

  13. Gas exchange in the Pee Dee River based on 222Rn evasion

    International Nuclear Information System (INIS)

    Moore, W.S.; Elsinger, R.J.

    1983-01-01

    Excess 222 Rn concentrations decrease downstream in the fresh water section of the Pee Dee River. Ground water is the primary source of the excess 222 Rn to the River. Using the radon concentration gradients determined during four sampling periods, gas exchange rates based on the stagnant film model are calculated. Stagnant film thicknesses range from 19 μm to 48 μm and mass transfer coefficients range from 2.1 m/d to 4.1 m/d

  14. The transport mechanisms of 222Rn in soil at Tateishi as an anomaly spot in Japan

    International Nuclear Information System (INIS)

    Iskandar, D.; Iida, T.; Yamazawa, H.; Moriizumi, J.; Koarashi, J.; Yamasoto, K.; Yamasaki, K.; Shimo, M.; Tsujimoto, T.; Ishikawa, S.; Fukuda, M.; Kojima, H.

    2005-01-01

    The 222 Rn concentration profiles in soil have been measured at an anomaly spot in Tateishi, Japan. In winter, the concentrations were low and showed a negative gradient with depth, but in other seasons, the concentration had both positive and negative gradients with depth, and dramatically changed by time. On the assumption that there was ventilation in deep layers and with driving forces of wind and temperatures, these phenomena were successfully explained. This finding would contribute to a numerical model for 222 Rn transport in soil

  15. Selection of design parameters of diffusion barrier in a passive 222Rn sampler based on activated charcoal adsorption

    International Nuclear Information System (INIS)

    Wei Suxia

    1992-01-01

    A method concerning selection of design parameters of diffusion barrier in a passive 222 Rn sampler based on activated charcoal adsorption. The proper parameter value of diffusion barrier is obtained by means of linearization of 222 Rn adsorption versus the exposure time. Thus, the influence of temperature on measured results may be greatly decreased, and higher sensitivity of the detector may be maintained

  16. Natural gamma radiation levels, indoor and water 222RN Concentrations in soil division of Kerio valley, kenya

    International Nuclear Information System (INIS)

    Nderitu, S.K.; Maina, D.M.; Kinyua, A.M.

    2001-01-01

    Human beings are constantly exposed to natural radioactivity. This radiation is mainly from natural gamma rays and radon and its decay products. The gamma rays are as a result of the decay of primordial nuclides and their daughter radioactive nuclides present in the earth's crust. Radon is produced from the decay of 226 Ra and it diffuses to the indoor environment through cracks on the floor or from building materials containing radium and hence radon problem is mainly indoors. In Kenya, some parts have been identified as having high gamma radiation causing exposure to the public. These areas include Mrima Hill (Kwale), Homa Bay, Bufayo, Weast Pokot, Kitui, Nanyuki, Kerio Valley and Tura. It is therefore necessary to carry out studies on the levels of radiation and determine whether they are within safe limits. Kerio valley, which is the area of study in this work, has been identified as one of the areas with uranium traces associated with fluorite mineralisation. In this study an assessment of the natural radiation levels in this area was carried out and in addition the radon concentrations indoor as well in water that the public is exposed were determined. To measure the radiation levels, soil samples were collected from the area of study, Kerio valley, and analysed for gamma levels using gamma spectroscopy technique. Indoor 222 Rn and radon in water concentrations were measured using the E-perm system. The activity concentrations of the radionuclides present, the doses as well as the annual effective dose equivalents were calculated for the soils using conversion factors adopted from the UNSCEAR (1988 and 1993) reports. Similarly, the dose equivalents and the annual effective doses for 222 Rn concentrations were evaluated. For natural gamma radiation 74 samples were analysed. The soil samples yielded activity concentrations ranging from 194.54??2.89 to 995.77??5.48 Bq Kg-1 for 40 K, 17.04??0.43 to 122.4??0.94 Bq Kg-1 for 232 Th which was evaluated from the 212

  17. Measurements of 222Rn and its daughters and estimation of internal doses to workers in underground buildings

    International Nuclear Information System (INIS)

    Cao Jianping; Lu Zhizhao; Li Yuanshan

    1993-03-01

    The results of concentration measuring of 222 Ru and its daughters and estimation of internal doses to workers in the underground buildings at Nanjing city are presented. The double filtering membrane method and Thomas method were used in the monitoring of 222 Rn and its daughters, and the dose conversion factor was taken from the latest UNSCEAR report. Concentration distributions of 222 Rn and its daughters were approximately log-normal. The geometric means for 222 Rn was 40.5 Bq · m -3 and for its daughters was 1.4 x 10 -7 J · m -3 . The equilibrium factor was 0.63. The radioactive equilibrium ratio between short-lived 222 Rn daughters was 1:0.57:0.49. The estimation value of annual effective dose equivalent from 222 Rn daughters to workers working at underground sites was 1.3 mSv, which was 86% higher than that of those working on ground sites

  18. Effect of cigarette smoke on the measured equivalent volume activity of 222Rn in air

    International Nuclear Information System (INIS)

    Tuckova, S.; Tykva, R.

    1994-01-01

    The effect of cigarette smoke in air on the increase of the measured equivalent volume activity of 222 Rn is demonstrated. After introduction of the smoke from one cigarette into 1 m 3 of air, this value increased up to ten times as shown be the method of sucking air through a filter. (author) 5 refs.; 1 fig

  19. Calibration of a degassing-emanation line for 222Rn determination in seawater samples

    International Nuclear Information System (INIS)

    Farias, Luciana Aparecida

    2002-01-01

    The purpose of this study is to calibrate a degassing-emanation line and to determine 222 Rn and 226 Ra activity concentrations in seawater samples. This methodology, also called Lucas method, consists in the extraction of radon (originally dissolved in seawater), collection of the gas in a liquid nitrogen cold trap and transfer from the trap to an alpha scintillation cell. Total extraction efficiencies of the 4 degassing-emanation systems were determined by measuring 226 Ra reference solutions. The efficiencies obtained for these 4 systems varied from 21 % to 62%. This work also presents preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil: Flamengo Bay, Fortaleza Bay, Mar Virado Bay and Ubatuba Bay. Concentration of Rn in excess varied from 0,011 to 0,317 Bq/L for Flamengo Bay, from 0,009 to 0,130 Bq/L for Fortaleza Bay, from 0,018 to 0,050 Bq/L for Mar Virado Bay and from 0,004 to 0,120 Bq/L for Ubatuba Bay. The results obtained for the concentration of 222 Rn in excess in a transect at Flamengo Bay varied from 0,002 to 0,036 Bq/L. Higher concentrations of 222 Rn in excess were obtained in Flamengo Bay, Fortaleza Bay and Ubatuba bay. It was also observed that the concentration of 222 Rn in excess increases with depth, as expected. (author)

  20. Measurement of 222Rn and 220Rn exhalation rate from soil samples of Kumaun Hills, India

    Science.gov (United States)

    Semwal, Poonam; Singh, Kuldeep; Agarwal, T. K.; Joshi, Manish; Pant, Preeti; Kandari, Tushar; Ramola, R. C.

    2018-03-01

    The source terms, i.e., exhalation and emanation from soil and building materials are the primary contributors to the radon (222Rn)/thoron (220Rn) concentration levels in the dwellings, while the ecological constraints like ventilation rate, temperature, pressure, humidity, etc., are the influencing factors. The present study is focused on Almora District of Kumaun, located in Himalayan belt of Uttarakhand, India. For the measurement of 222Rn and 220Rn exhalation rates, 24 soil samples were collected from different locations. Gamma radiation level was measured at each of these locations. Chamber technique associated with Smart Rn Duo portable monitor was employed for the estimation of 222Rn and 220Rn exhalation rates. Radionuclides (226Ra, 232Th and 40K) concentrations were also measured in soil samples using NaI(Tl) scintillation based gamma ray spectrometry. The mass exhalation rate for 222Rn was varying between 16 and 54 mBq/kg/h, while the 220Rn surface exhalation rate was in the range of 0.65-6.43 Bq/m2/s. Measured gamma dose rate for the same region varied from 0.10 to 0.31 µSv/h. Inter-correlation of exhalation rates and intra-correlation with background gamma levels were studied.

  1. Health effects assessment in population exposed to 222Rn in drinking water

    International Nuclear Information System (INIS)

    Burkhardt, R.; Mocsy, I.; Muntean, N.

    1996-01-01

    The carcinogenetic effect produce by ionizing radiation upon human health, mainly by drinking water consumption with an elevated 222 Rn content is well documented. The objective of the paper was to demonstrated the possible relationship between the incidence of pulmonary and gastric cancer and 222 Rn presence in water and indoor air. The 222 Rn content was assessed by the standard method in drinking water sampled in two sources in Transylvania area from located in Tirgu Mures and Miercurea Ciuc towns. The 222 Rn concentration in indoor air was indirectly determined. On the basis of the registered values the pulmonary and gastric internal dose received by the residents of the towns was calculated. In parallel was performed a retrospective epidemiological study (1980-1992) regarding the incidence of gastric and pulmonary cancer in two towns in terms of morbidity, mortality and lethality indices. By comparing the estimated carcinogenic risk for this type of cancer with the specific mortality rate registered in our study, we estimate the contribution of 222 R to the cancer mortality percentage in the two towns, as follows: 0.47% for Tirgu Mures and 0.01% for Miercurea Ciuc town for pulmonary cancer and 0.23% and 0.015% for gastric cancer. (author)

  2. Distribution Log Normal of 222 Rn in the state of Zacatecas, Mexico

    International Nuclear Information System (INIS)

    Garcia, M.L.; Mireles, F.; Quirino, L.; Davila, I.; Rios, C.; Pinedo, J.L.

    2006-01-01

    In this work the evaluation of the concentration of 222 Rn in air for Zacatecas is shown. The Solid State Nuclear Track Detectors were used as the technique for the realization of the measurements in large scale with cellulose nitrate LR-115, type 2, in open chambers of 222 Rn. The measurements were carried out during three months in different times of the year. In the results it is presented the log normal distribution, arithmetic mean and geometric media for the concentration at indoor and outdoor of residence constructions, the concentration at indoor of occupational constructions and in the 57 municipal heads of the state of Zacatecas. The statistics of the values in the concentration showed variation according to the time of the year, obtaining high quantities in winter seasons for both cases. The distribution of the concentration of 222 Rn is presented in the state map for each one of the municipalities, representing the measurement places in the entire state of Zacatecas. Finally the places where the values in the concentration of 222 Rn in air are near to the one limit settled down by the EPA of 148 Bq/m 3 are presented. (Author)

  3. Fresh Versus Marine Submarine Groundwater Discharge: How 222Rn Might Help Distinguish These Two Sources

    Science.gov (United States)

    Smith, C. G.; Cable, J. E.; Martin, J. B.; Roy, M.

    2008-05-01

    Pore water distributions of 222Rn (t1/2 = 3.83 d), obtained during two sampling trips 9-12 May 2005 and 6-8 May 2006, are used to determine spatial and temporal variations of fluid discharge from a seepage face located along the mainland shoreline of Indian River Lagoon, Florida. Porewater samples were collected from a 30 m transect of multi-level piezometers and analyzed for 222Rn via liquid scintillation counting; the mean of triplicate measurements was used to represent the porewater 222Rn activities. Sediment samples were collected from five vibracores (0, 10, 17.5, 20, and 30 m offshore) and emanation rates of 222Rn (sediment supported) were determined using a standard cryogenic extraction technique. A conceptual 222Rn transport model and subsequent numerical model were developed based on the vertical distribution of dissolved and sediment-supported 222Rn and applicable processes occurring along the seepage face (e.g. advection, diffusion, and nonlocal exchange). The model was solved inversely with the addition of two Monte Carlo (MC) simulations to increase the statistical reliability of three parameters: fresh groundwater seepage velocity (v), irrigation intensity (α0), and irrigation attenuation (α1). The first MC simulation ensures that the Nelder-Mead minimization algorithm converges on a global minimum of the merit function and that the parameters estimates are consistent within this global minimum. The second MC simulation provides 90% confidence intervals on the parameter estimates using the measured 222Rn activity variance. Fresh groundwater seepage velocities obtained from the model decrease linearly with distance from the shoreline; seepage velocities range between 0.6 and 42.2 cm d-1. Based on this linear relationship, the terminus of the fresh groundwater seepage is approximately 25 m offshore and total fresh groundwater discharge for the May-2005 and May-2006 sampling trips are 1.16 and 1.45 m3 d-1 m-1 of shoreline, respectively. We hypothesize

  4. Soil gas 222Rn and volcanic activity at El Hierro (Canary Islands) before and after the 2011 submarine eruption

    Science.gov (United States)

    Padilla, G.; Hernández, P. A.; Padrón, E.; Barrancos, J.; Melián, G.; Dionis, S.; Rodríguez, F.; Nolasco, D.; Calvo, D.; Hernández, I.; Pereza, M. D.; Pérez, N. M.

    2012-04-01

    El Hierro (278 km2) is the southwesternmost island of the Canarian archipelago. From June 19, 2011 to January 2012, more than 11,950 seismic events have been detected by the seismic network of IGN. On 10 October 2011 the earthquake swarm changed its behaviour and produced a harmonic tremor due to magma movement, indicating that a submarine eruption located at 2 km south of La Restinga had started which is still in progress. Since 2003, the ITER Environmental Research Division now integrated in the Instituto Volcanológico de Canarias, INVOLCAN, has regularly performed soil gas surveys at El Hierro as a geochemical tool for volcanic surveillance. Among the investigated gases, soil gas radon (222Rn) and thoron (220Rn) have played a special attention. Both gases are characterized to ascend towards the surface mainly through cracks or faults via diffusion or advection, mechanisms dependent of both soil porosity and permeability, which in turn vary as a function of the stress/strain changes at depth. Years before the starts of the volcanic-seismic crisis on July 17, 2011, a volcanic multidisciplinary surveillance program was implemented at El Hierro including discrete and continuous measurements of 222Rn and 220Rn. Two soil gas 222Rn surveys had been carried out at El Hierro in 2003 and 2011, and four continuous geochemical monitoring stations for 222Rn and 220Rn measurements had been installed (HIE02, HIE03, HIE04 and HIE08). Soil gas 222Rn surveys were carried out at the surface environment of El Hierro after selecting 600 sampling observation sites (about 40 cm depth). Geochemical stations measure 222Rn and 220Rn activities by pumping the gas from a PVC pipe inserted 1m in the ground and thermally isolated. The results of the 2003 and 2011 soil gas 222Rn surveys show clearly a relatively higher observed 222Rn activities in the surface environment on 2011 than those observed on 2003 when no anomalous seismicity were taking place beneath El Hierro. The observed

  5. (222)Rn activity in groundwater of the St. Lawrence Lowlands, Quebec, eastern Canada: relation with local geology and health hazard.

    Science.gov (United States)

    Pinti, Daniele L; Retailleau, Sophie; Barnetche, Diogo; Moreira, Floriane; Moritz, Anja M; Larocque, Marie; Gélinas, Yves; Lefebvre, René; Hélie, Jean-François; Valadez, Arisai

    2014-10-01

    One hundred ninety-eight groundwater wells were sampled to measure the (222)Rn activity in the region between Montreal and Quebec City, eastern Canada. The aim of this study was to relate the spatial distribution of (222)Rn activity to the geology and the hydrogeology of the study area and to estimate the potential health risks associated with (222)Rn in the most populated area of the Province of Quebec. Most of the groundwater samples show low (222)Rn activities with a median value of 8.6 Bq/L. Ninety percent of samples show (222)Rn activity lower than 100 Bq/L, the exposure limit in groundwater recommended by the World Health Organization. A few higher (222)Rn activities (up to 310 Bq/L) have been measured in wells from the Appalachian Mountains and from the magmatic intrusion of Mont-Saint-Hilaire, known for its high level of indoor radon. The spatial distribution of (222)Rn activity seems to be related mainly to lithology differences between U-richer metasediments of the Appalachian Mountains and magmatic intrusions and the carbonaceous silty shales of the St. Lawrence Platform. Radon is slightly enriched in sodium-chlorine waters that evolved at contact with clay-rich formations. (226)Ra, the parent element of (222)Rn could be easily adsorbed on clays, creating a favorable environment for the production and release of (222)Rn into groundwater. The contribution of groundwater radon to indoor radon or by ingestion is minimal except for specific areas near Mont-Saint-Hilaire or in the Appalachian Mountains where this contribution could reach 45% of the total radioactive annual dose. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Expected indoor 222Rn levels in counties with very high and very low lung cancer rates

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1989-01-01

    Counties in the US with high lung cancer rates should have higher average 222 Rn levels than counties with low lung cancer rates, assuming the average 222 Rn level in a county is not correlated with other factors that cause lung cancer. The magnitude of this effect was calculated, using the absolute risk model, the relative risk model, and an intermediate model, for females who died in 1950-1969. The results were similar for all three models. We concluded that, ignoring migration, the average Rn level in the highest lung cancer counties should be about three times higher than in the lowest lung cancer counties according to the theory. Preliminary data are presented indicating that the situation is quite the opposite: The average Rn level in the highest lung cancer counties was only about one-half that in the lowest lung cancer counties

  7. Non-occupational radiation exposures from 222Rn and daughters to residents of Grand Junction, Colorado

    International Nuclear Information System (INIS)

    Spitz, H.B.; Cohen, N.; Wrenn, M.E.

    1975-01-01

    Six individuals from GRAND Junction, Colorado were examined for 210 Pb body burdens as a result of living in homes where concentrations of 222 Rn were elevated due to the presence of uranium mill tailings beneath the building foundation. In vivo detection for 210 Pb using three NaI--CsI (Tl) thin crystals in the standard NYU head geometry identified two persons with estimaed body burdens above 1.1 nCi. Bioassay for 210 Pb was also performed to compare with the in vivo analysis and to further substantiate the relationship between 210 Pb in bone, blood, and urine. estimates of exposure in cumulative working level months (CWLM), range 85 to 566 CWLM, were used to calculate expected body burdens of 210 Pb. The NYU continuous readout radon monitor provided diurnal measurements of 222 Rn in the homes of the volunteer subjects so that, considering assumptions about ventilation and residence times, actual exposures could be determined. (U.S.)

  8. A multi-detector continuous monitor for assessment of 222Rn in the coastal ocean

    International Nuclear Information System (INIS)

    Dulaiova, H.; Peterson, R.; Burnett, W.C.

    2005-01-01

    Radon-222 is a good natural tracer of groundwater discharge and other physical processes in the coastal ocean. Unfortunately, its usefulness is limited by the time consuming nature of collecting individual samples and traditional analysis schemes. An automated multi-detector system is demonstrated that can be used in a continuous survey basis to assess radon activities in coastal ocean waters. The system analyses 222 Rn from a constant stream of water delivered by a submersible pump to an air-water exchanger where radon in the water phase equilibrates with radon in a closed air loop. The air stream is fed to 3 commercial radon-in-air monitors connected in parallel to determine the activity of 222 Rn. By running the detectors out of phase, it is possible to obtain as many as 6 readings per hour with a precision of approximately ±5-15% for typical coastal seawater concentrations. (author)

  9. Effects of air conditioning, dehumidification and natural ventilation on indoor concentrations of 222Rn and 220Rn

    International Nuclear Information System (INIS)

    Lee, Thomas K.C.; Yu, K.N.

    2000-01-01

    A bedroom was selected for detailed measurements on 220 Rn and 222 Rn concentrations and environmental parameters including CO 2 concentration, temperature and relative humidity. To simulate different sealing conditions, five conditions were artificially created in the sampling period of 25 consecutive days. It was concluded that natural ventilation is the most efficient way to lower the 222 Rn levels, while air conditioning is the next. Dehumidification provides only a marginal reduction of 222 Rn levels. The 220 Rn concentrations are not affected by natural ventilation, air conditioner or dehumidification, and were all around 10 Bq m -3 . There are no significant correlations between the 220 Rn and 222 Rn concentrations and environmental conditions such as CO 2 concentrations, temperature, relative humidity and pressure

  10. Measurements of indoor 222RN activity in dwellings and workplaces of Curitiba (Brazil)

    International Nuclear Information System (INIS)

    Corrêa, Janine N.; Paschuk, Sergei A.; Del Claro, Flávia; Kappke, Jaqueline; Perna, Allan F.N.; Schelin, Hugo R.; Denyak, Valeriy

    2014-01-01

    The present work describes the results of systematic measurements of radon ( 222 Rn) in residential environments and workplaces in the Metropolitan Region of Curitiba (Paraná State, Brazil) during the period 2004–2012. For radon in air activity measurements, polycarbonate Track Etch Detectors CR-39, mounted in diffusion chambers protected by borosilicate glass fiber filters, were used. After being exposed in air, the CR-39 detectors were submitted to a chemical etching in a 6.25 M NaOH solution at 70 °C for 14 h. The alpha particle tracks were identified and manually counted with an optical microscope, and with the results of previously performed calibrations, the indoor activity concentration of 222 Rn was calculated. The calibration of CR-39 and the alpha particle tracks chemical development procedures were performed in collaboration the National Institute of Radiological Sciences (NIRS, Japan). The major part of indoor 222 Rn concentration in residences was found to be below 100 Bq/m 3 . In the case of working places, all measurements of 222 Rn concentrations were below 100 Bq/m 3 . These values are considered within the limits set by international regulatory agencies, such as the US EPA and ICRP, which adopt up to 148 and 300 Bq/m 3 as upper values for the reference levels for radon gas activity in dwellings, respectively. The latest value of 300 Bq/m 3 for radon activity in air is proposed by ICRP considering the upper value for the individual dose reference level for radon exposure of 10 mSv/yr. - Highlights: • Radon activity in air of dwellings was measured. • Radon activity in air of workplaces was measured. • Obtained experimental results are compared with International Norms and Regulations

  11. Measure of activities and calculation of effective dose of indoor 222Rn in some dwellings and enclosed areas in Morrocco

    International Nuclear Information System (INIS)

    Choukri, A.; Hakam, O.-K.

    2010-01-01

    Radon gas ( 222 Rn) is found in the environment and is an occurring radioactive gas that is originated from the decay of uranium in rocks and soils. It is colorless, odorless, and tasteless and can only be measured using special equipment. Ionizing radiations are present at all time and at all places on the earth. Radon is one of the principal sources of natural radiation exposure. Most of this exposure occurs inside homes. Radon levels are governed by many factors, like local geology, atmospheric conditions, air exchange rate, wind velocity, and the orientation of the house. The inhalation of radon causes a high number of lung cancer cases, which are reported annually (UNSCEAR, 2000). Exposure to radon in dwellings and workplaces may arise from existing exposure situations or from practices. The results of various international surveys have demonstrated an increase in radon concentration levels in houses and, consequently, a continuously growing concern about its health effects to the population. Experimental The passive time integrated method of using a solid state nuclear track detector (LR-115 type II) was employed. Stations of Radon measurements Stations of measure were implanted in some regions of Morocco. However, measurements were only made in the places where voluntary correspondents were found having agreed to install detectors. These were in houses in the following cities: Rabat, Casablanca, Kenitra, El Jadida, Berchid, Khouribga, Youssoufia, Ouarzazate and Oujda. Results The volumic activities of radon vary in Houses, between 31and 136 Bq/m3 with an average value of 80 Bq/m3. This value is comparable to those found in the other regions of the world. In enclosed work area, the volumic activities of radon vary between 60 Bq/m3 in an ordinary area to 1884 Bq/m3 at not airy underground level of 12 m. The effective dose per unit exposure to radon and radon progeny was obtained using the so-called dose conversion convention as defined by ICRP (1993; 1994

  12. Seasonal variations of 222Rn and SGD fluxes to Ubatuba embayments, Sao Paulo

    International Nuclear Information System (INIS)

    Oliveira, J.; Costa, P.; Braga, E.S.

    2006-01-01

    We describe here an application of excess 222 Rn to estimate submarine groundwater discharge in a series of small embayments of Ubatuba, Sao Paulo State, Brazil. Excess 222 Rn inventories obtained in 11 vertical profiles varied from (3.3±1.1) x 10 3 to (19±5) x 10 3 dpm x m -2 . The estimated total fluxes required to support the inventories varied from (0.6±0.2) x 10 3 to (3.4±0.9) x 10 3 dpm x m -2 x d -1 . Considering these results, the submarine groundwater discharge advective rates necessary to balance the sub-pycnocline fluxes calculated in Ubatuba embayments ranged from 0.06 to 1.9 cm x d -1 . During the period of this investigation (from March/03 to May/2004), the highest 222 Rn in excess inventories were observed late in the summer season (March). Taking into account all vertical profiles established, the relative variability was 67%. Although, if we consider only the fluxes determined in both Flamengo and Fortaleza embayments, the relative variation was 21%. (author)

  13. Determination of {sup 222}Rn in groundwater - Recent applications for the investigation of river bank infiltration

    Energy Technology Data Exchange (ETDEWEB)

    Freyer, K.; Treutler, H.C. [Leipzig-Halle Ltd, Permoserstr, Leipzig (Germany). Centre for Environmental Research; Dehnert, J.; Nestler, W. [Hochschule fuer Technik und Wirtschaft Dresrden, Dresden (Germany)

    1997-10-01

    With a half life of 3.8 days, the {sup 222}Rn found in all groundwater makes an excellent tracer for solving several problems in the field of environmental research and hydrology. In Germany alluvial aquifers connected to rivers are used for drinking water extraction. Consequently importance is attached to studying the exchange processes between surface water and groundwater in order to determine infiltration velocities and infiltrate retention times in the aquifer. However, such investigations require a reliable, reproducible method for determining radon activity concentrations in groundwater samples, as well as a suitable sampling technique. This paper reports on just such a method, containing detailed instructions for sampling, transportation and activity determination using liquid scintillation spectrometry following toluene extraction. Spectral analysis and {alpha}/{beta} separation improve the accuracy of measurement. The detection limit is about 0.05 Bq/1; the total error is <{+-}10%. Infiltration processes are studied with {sup 222}Rn by employing the effect that surface water infiltrating an aquifer absorbs {sup 222}Rn along the infiltration pathway. As the degree of uptake is a function of the retention time, flow paths and flow velocities can all be determined by measuring the radon activity concentrations at the various groundwater gauging stations along measuring profiles. Corresponding investigations were carried out into a pleistocene aquifer below the River Elbe near a waterworks extracting bank-filtered water. The findings are presented and the technique`s possibilities and limitations are discussed 12 refs., 3 figs.

  14. Use of 222Rn-resistant techniques in new home construction

    International Nuclear Information System (INIS)

    Watson, J.E. Jr.; Cote, R.A.

    1999-01-01

    The objective of this project was to assess the status of the use of 222 Rn-resistant construction techniques in new home construction in the eight Zone 1 counties of North Carolina. Zone 1 counties have an average predicted indoor 222 Rn screening potential greater than 148 Bq m -3 (4 pCi L -1 ). To facilitate a response from builders, a brief survey form was designed and printed on the back of a self-addressed, postage-paid postcard. This survey form was mailed to 460 home builders in the Zone 1 counties. The response rate was 17%, which can be compared to the 4.9% response rate obtained in a national survey conducted by the National Association of Home Builders Research Center. In their survey, 62% of the responding builders reported that they had built some or many homes in 1996 using construction techniques to reduce the entry of radon into homes, but only 10% of the builders reported using these techniques for many homes. The National Association of Home Builders survey determined that, nationally, 30% of homes built in Zone 1 counties had 222 Rn venting features. There is the potential for bias in the results of their survey (as well as in the results of the National Association of Home Builders survey) since the response rates were low

  15. Determination of 222Rn in groundwater - Recent applications for the investigation of river bank infiltration

    International Nuclear Information System (INIS)

    Freyer, K.; Treutler, H.C.

    1997-01-01

    With a half life of 3.8 days, the 222 Rn found in all groundwater makes an excellent tracer for solving several problems in the field of environmental research and hydrology. In Germany alluvial aquifers connected to rivers are used for drinking water extraction. Consequently importance is attached to studying the exchange processes between surface water and groundwater in order to determine infiltration velocities and infiltrate retention times in the aquifer. However, such investigations require a reliable, reproducible method for determining radon activity concentrations in groundwater samples, as well as a suitable sampling technique. This paper reports on just such a method, containing detailed instructions for sampling, transportation and activity determination using liquid scintillation spectrometry following toluene extraction. Spectral analysis and α/β separation improve the accuracy of measurement. The detection limit is about 0.05 Bq/1; the total error is 222 Rn by employing the effect that surface water infiltrating an aquifer absorbs 222 Rn along the infiltration pathway. As the degree of uptake is a function of the retention time, flow paths and flow velocities can all be determined by measuring the radon activity concentrations at the various groundwater gauging stations along measuring profiles. Corresponding investigations were carried out into a pleistocene aquifer below the River Elbe near a waterworks extracting bank-filtered water. The findings are presented and the technique's possibilities and limitations are discussed

  16. A sub-nationwide survey of outdoor and indoor 222Rn concentrations in China by passive method

    International Nuclear Information System (INIS)

    Jin Yihe; Ikebe, Y.; Iida, T.

    1996-01-01

    From Nov. 1988 to Mar. 1993, cooperated by China and Japan, a survey of outdoor and indoor 222 Rn concentrations in 10 cities which were highly populated in China was carried out by means of passive method. the annual mean of outdoor 222 Rn concentration in 10 cities was 8.8 Bq·m -3 . The highest of 13.5 Bq·m -3 was in Wuhan, the lowest of 3.3 Bq·m -3 was in Chongming Island of Shanghai; and there were no significant differences among the different years in the same areas. During the northwest wind seasons, about 50% of outdoor 222 Rn concentration in Taiwan was contributed by the airflow from the mainland. Typical apartment houses and offices built of brick and concrete were also surveyed for indoor 222 Rn concentration. The annual mean of indoor 222 Rn concentration in the 10 cities was 19.5 Bq·m - 3. The highest of 33.9 Bq·m -3 was observed in Guiyang, the lowest of 9.0 Bq·m -3 was observed in Chongming Island of Shanghai. The outdoor and indoor 222 Rn concentrations showed a clear seasonal pattern with the minimum in summer and the maximum in winter. And they also showed a clear geographic distribution tendency; they were higher in inland than in seashores, and higher in the south than in the north. The ratios of indoor to outdoor 222 Rn concentrations were from 1.1 to 4.6. The annual effective dose equivalents resulting from outdoor and indoor 222 Rn concentrations amounted to about 0.64 mSv·a -1 . The highest was in Guiyang, and the lowest was in Nantong, being 1.12 and 0.39 mSv·a -1 , respectively

  17. Determination of 222Rn in water samples from wells and springs in Tokyo by a modified integral counting method

    International Nuclear Information System (INIS)

    Homma, Y.; Murase, Y.; Handa, K.; Murakami, I.

    1997-01-01

    222 Rn in 2L-water samples was extracted with 30 mL toluene, and 21 mL of the toluene solution was transferred into a liquid scintillation vial, in which PPO - 2,5-diphenyloxazole was placed in advance. The total activity of 222 Rn in the water sample was calculated based on the Ostwald's coefficient of solubilities of 222 Rn in toluene and water at the temperature of the sample water and the volume of water and toluene. About 40% of 222 Rn dissolved in 2L-water sample can be collected. After allowing to stand for 3.5 h, the equilibrium mixture of 222 Rn and its daughters was measured with an Aloka liquid scintillation spectrometer using a modified integral counting method which extrapolates the integral counting curve not to the zero pulse-height, but to the zero detection threshold, an average energy required to produce a measurable pulse, of the liquid scintillation spectrometer. The general method which agitates water sample (usually about 10 mL) with a liquid scintillation cocktail is practical when the activity of 222 Rn is high. By adding 10 mL of water sample, however, it is possible also to add variable amounts of quencher. In some cases water sample is preserved with nitric acid. The slope of the integral counting rate curve increases as quench level of the sample increases. Therefore, it is clear that the modified integral counting method gives more accurate 222 Rn concentrations for water samples of strong quench than the conventional integral counting method. 222 Rn sample of 0.2 Bq/L can be determined within an overall uncertainty of 3.1%

  18. Study of gel materials as radioactive 222Rn gas detectors

    International Nuclear Information System (INIS)

    Espinosa, G.; Golzarri, J. I.; Rickards, J.; Gammage, R. B.

    2006-01-01

    Commercial hair gel material (polyvinyl pyrolidone triethanolamine carbo-pol in water) and bacteriological agar (phycocolloid extracted from a group of red-purple algae, usually Gelidium sp.) have been studied as radioactive radon gas detectors. The detection method is based on the diffusion of the radioactive gas in the gel material, and the subsequent measurement of trapped products of the natural decay of radon by gamma spectrometry. From the several radon daughters with gamma radiation emission ( 214 Pb, 214 Bi, 214 Po, 210 Pb, 210 Po), two elements, 214 Pb (0.352 MeV) and 214 Bi (0.609 MeV), were chosen for the analysis in this work; in order to determine the best sensitivity, corrections were made for the short half-life of the analysed isotopes. For the gamma spectrometry analysis, a hyper-pure germanium solid state detector was used, associated with a PC multichannel analyser card with Maestro R and Microsoft R Excel R software. The results show the viability of the method: a linear response in a wide radon concentration range (450-10,000 Bq m -3 ), reproducibility of data, easy handling and low cost of the gel material. This detection methodology opens new possibilities for measurements of radon and other radioactive gases. (authors)

  19. Evaluation of occupational exposure in a underground coal mine by environmental measures of 222Rn and in vivo measurements of 210Pb in bones

    International Nuclear Information System (INIS)

    Dantas, A.L.A.; Veiga, L.H.S.; Dantas, B.M.; Melo, V.P.

    2005-01-01

    A radiological survey performed in an underground coal mining in the State of Parana, southern Brazil, has indicated the occurrence of high levels of concentration of radon and its decay products. The levels of 222 Rn concentration measured in the basement of this mine, in the period from 1999 to 2003 ranged from 2000 to 7000 Bq m -3 . It is estimated, for these workers, an average annual exposure of 2.1 WLM ranging from 0.2 to 7.2 WLM. A retrospective mortality study conducted with 2856 miners of this mining indicated a risk of lung cancer mortality greater than the one expected for the male population of the State. In this study the cumulative exposure to radon cannot be estimated since there was no radon measures in other periods. In this way, the cumulative exposure can be evaluated by through 210 Pb activities monitored in the skeleton. The measures of 210 Pb in skeleton ranged from 83 to 164 Bq, indicating that these workers were significantly exposed to 222 Rn. These results show that cumulative exposure to radon has been higher than estimated based on recent measures of the activity concentration of radon in the workplace and is compatible with the risk determined in the epidemiological study

  20. Comparison of the quantulus 1220 and 300SL liquid scintillation counters for the analysis of {sup 222}Rn in groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Cheol; Jung, Yoon Hee; Lee, Wanno; Choi, Guen Sik; Chung, Kun Ho; Kang, Mun Ja [Environmental Radioactivity Assessment Team, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-12-15

    Liquid scintillation counters (LSCs) are commonly used as an analytical method for detecting {sup 222}Rn in groundwater because they involve a simple sample pretreatment and allow high throughout with an autosampler. The Quantulus 1220 is the best-selling LSC in Korea, but its production was stopped. Recently, a new type of LSC, the 300SL, was introduced. In this study, the 300SL was compared with the Quantulus 1220 in order to evaluate the ability of each apparatus to detect {sup 222}Rn in groundwater. The Quantulus 1220 and 300SL were used to detect the presence of {sup 222}Rn. Radon gas was extracted from a groundwater sample using a water-immiscible cocktail in a LSC vial. The optimal analytical conditions for each LSC were determined using a {sup 222}Rn calibration source prepared with a {sup 226}Ra source. The optimal pulse shape analysis level for alpha and beta separation was 80 for the Quantulus 1220, and the corresponding pulse length index was 12 in the 300SL. The counting efficiency of the Quantulus 1220 for alpha emissions was similar to that of the 300SL, but the background count rate of the Quantulus 1220 was 10 times lower than that of the 300SL. The minimum detectable activity of the Quantulus 1220 was 0.08 Bq·L{sup -,} while that of the 300SL was 0.20 Bq·L{sup -1}. The analytical results regarding {sup 222}Rn in groundwater were less than 10% different between these LSCs. The 300SL is an LSC that is comparable to the Quantulus 1220 for detecting {sup 222}Rn in groundwater. Both LSCs can be applied to determine the levels of {sup 222}Rn in groundwater under the management of the Ministry of Environment.

  1. Application of {sup 222} Rn as a tracer of groundwater discharge at the coastal zone of Ubatuba, Sao Paulo State, Brazil; Aplicacao de {sup 222} Rn como tracador da descarga de aguas subterraneas na regiao costeira de Ubatuba, Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Joselene de; Farias, Luciana A.; Mazzilli, Barbara P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Dept. de Radiometria Ambiental]. E-mail: jolivei@net.ipen.br; Burnett, William C. [Florida State Univ., Tallahassee, FL (United States); Saraiva, Elisabete de S.B. e; Furtado, Valdenir V. [Sao Paulo Univ., SP (Brazil). Inst. Oceanografico. Dept. de Oceanografia Quimica e Geologica

    2002-07-01

    Submarine groundwater discharge (SGD) and recycled seawater can provide chemical constituents to coastal zone, representing an important material flux pathway from land to sea in some areas. Geochemical tracers, like {sup 222} Rn and {sup 226} Ra, are advantageous for regional-scale assessment of SGD, because their signals represent values integrated through the water column that removes small-scale variations. These radionuclides are usually enriched in groundwater compared to seawater, can be measured at very low concentrations and are conservative. This work reports preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil, covering latitudes between 23 deg 26{sup '}S and 23 deg 46{sup '}S and longitudes between 45 deg02{sup '}W and 45 deg 11{sup '}W. The main aims of this research were to set up an analytical method to assess {sup 222} Rn and {sup 226} Ra activities in seawater samples and to apply the excess {sup 222} Rn inventories obtained to estimate the submarine groundwater discharge. Measurements made during 2001/2002 included {sup 222} Rn and {sup 226} Ra in seawater, {sup 222} Rn in sediment, seawater and sediment physical properties. (author)

  2. Atmospheric Residence Times of Continental Aerosols.

    Science.gov (United States)

    Balkanski, Yves Jacques

    The global atmospheric distributions of ^{222}Rn and ^{210 }Pb are simulated with a three-dimensional model of atmospheric transport based on the meteorology of the NASA GISS^1>=neral circulation model. The short-lived radioactive gas ^ {222}Rn (half-life = 3.8d) is emitted almost exclusively from land, at a relatively uniform rate; hence it is an excellent tracer of continental influences. Lead -210 is produced by decay of ^{222} Rn and immediately condenses to preexisting aerosol surfaces. It provides an excellent measure of aerosol residence times in the atmosphere because its source is accurately defined by the ^{222} Rn distribution. Results from the three-dimensional model are compared to measurements of ^ {222}Rn and ^{210 }Pb atmospheric concentrations to evaluate model's long-range transport over oceanic regions and to study the deposition mechanisms of atmospheric aerosols. Model results for ^{222} Rn are used to examine the long-range transport of continental air over two selected oceanic regions, the subantartic Indian Ocean and the North Pacific. It is shown that fast transport of air from southern Africa causes substantial continental pollution at southern mid-latitudes, a region usually regarded as pristine. Air over the North Pacific is heavily impacted by continental influences year round, but the altitude at which the transport occurs varies seasonally. Observations of aerosols at island sites, which are commonly used as diagnostics of continental influences, may be misleading because they do not account for influences at high altitude and because aerosols are efficiently scavenged by deposition during transport. The study of ^{210}Pb focuses on defining the residence times of submicron aerosols in the troposphere. Scavenging in wet convective updrafts is found to provide the dominant sink on a global scale. The globally averaged residence time for ^{210 }Pb-containing aerosols in the troposphere is 7 days. The average increase in residence time

  3. Using {sup 222}Rn as a tracer of geodynamical processes in underground environments

    Energy Technology Data Exchange (ETDEWEB)

    Valladares, D.L. [GEA, Instituto de Matemática Aplicada San Luis (IMASL), Universidad Nacional de San Luis, Consejo Nacional de Investigaciones Científicas y Técnicas, Ej. de los Andes 950, D5700HHW San Luis (Argentina); Silva, A.A.R. da [Instituto de Física, Universidade de São Paulo, P.O.Box 66318, 05314-970, São Paulo, SP (Brazil); Serviço Especializado em Engenharia de Segurança e Medicina do Trabalho, Departamento de Saúde, Universidade de São Paulo, Rua da Reitoria, 109, 05508-900, São Paulo, SP (Brazil); Lacerda, T. [Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/n" o, Gragoatá, 24210-340, Niterói, RJ (Brazil); Anjos, R.M., E-mail: meigikos@if.uff.br [Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/n" o, Gragoatá, 24210-340, Niterói, RJ (Brazil); Rizzotto, M.; Velasco, H.; Rosas, J.P. de [GEA, Instituto de Matemática Aplicada San Luis (IMASL), Universidad Nacional de San Luis, Consejo Nacional de Investigaciones Científicas y Técnicas, Ej. de los Andes 950, D5700HHW San Luis (Argentina); Tognelli, G. [Departamento de Geología, Universidad Nacional de San Luis, Ej. de los Andes 950, D5700HHW San Luis (Argentina); and others

    2014-01-01

    Radon levels in two old mines in San Luis, Argentina, were measured and analyzed, with the aim to assess the potential use of this radioactive noble gas as a tracer of geological processes in underground environments. La Carolina gold mine and Los Cóndores tungsten mine are today used as tourism mines. CR-39 nuclear track detectors were used for this purpose. Measurements were performed during both winter and summer seasons. The findings show that in these environments, significant radon concentrations are subject to large seasonal fluctuations, due to the strong dependence on natural ventilation with the outside temperature variations. For both mines, higher concentration values of {sup 222}Rn were observed in summer than in winter; with an extreme ratio of 2.5 times between summer and winter seasons for Los Cóndores mine. The pattern of radon transport inside La Carolina mine revealed, contrary to what was believed, that this mine behaves as a system with two entrances located at different levels. However, this feature can only be observed in the winter season, when there is a marked difference between the inside and outside temperatures of the mine. In the case of Los Cóndores mine, the radon concentration pattern distribution is principally established by air current due to chimney-effect in summer and winter seasons. In both cases, the analyses of radon pattern distribution appear as a good method to trace air currents, and then localize unknown ducts, fissures or secondary tunnels in subterranean environments. - Highlights: • {sup 222}Rn levels in two old mines in San Luis, Argentina • CR-39 nuclear track detectors were used for this purpose • higher concentration values of {sup 222}Rn were observed in summer than in winter • radon pattern distribution appear as a good method to trace air currents • it localizes unknown ducts, fissures or secondary tunnels in subterranean environments.

  4. Using 222Rn as a tracer of geodynamical processes in underground environments

    International Nuclear Information System (INIS)

    Valladares, D.L.; Silva, A.A.R. da; o, Gragoatá, 24210-340, Niterói, RJ (Brazil))" data-affiliation=" (Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoatá, 24210-340, Niterói, RJ (Brazil))" >Lacerda, T.; o, Gragoatá, 24210-340, Niterói, RJ (Brazil))" data-affiliation=" (Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoatá, 24210-340, Niterói, RJ (Brazil))" >Anjos, R.M.; Rizzotto, M.; Velasco, H.; Rosas, J.P. de; Tognelli, G.

    2014-01-01

    Radon levels in two old mines in San Luis, Argentina, were measured and analyzed, with the aim to assess the potential use of this radioactive noble gas as a tracer of geological processes in underground environments. La Carolina gold mine and Los Cóndores tungsten mine are today used as tourism mines. CR-39 nuclear track detectors were used for this purpose. Measurements were performed during both winter and summer seasons. The findings show that in these environments, significant radon concentrations are subject to large seasonal fluctuations, due to the strong dependence on natural ventilation with the outside temperature variations. For both mines, higher concentration values of 222 Rn were observed in summer than in winter; with an extreme ratio of 2.5 times between summer and winter seasons for Los Cóndores mine. The pattern of radon transport inside La Carolina mine revealed, contrary to what was believed, that this mine behaves as a system with two entrances located at different levels. However, this feature can only be observed in the winter season, when there is a marked difference between the inside and outside temperatures of the mine. In the case of Los Cóndores mine, the radon concentration pattern distribution is principally established by air current due to chimney-effect in summer and winter seasons. In both cases, the analyses of radon pattern distribution appear as a good method to trace air currents, and then localize unknown ducts, fissures or secondary tunnels in subterranean environments. - Highlights: • 222 Rn levels in two old mines in San Luis, Argentina • CR-39 nuclear track detectors were used for this purpose • higher concentration values of 222 Rn were observed in summer than in winter • radon pattern distribution appear as a good method to trace air currents • it localizes unknown ducts, fissures or secondary tunnels in subterranean environments

  5. Parameters of calibration of the measurement system of {sup 222} Rn based in LR-115; Parametros de calibracion del sistema de medicion de {sup 222} Rn basado en LR-115

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M.L.; Mireles, F.; Quirino, L.; Davila, I.; Lugo, F.; Pinedo, J.L. [CREN-UAZ, 98068 Zacatecas (Mexico); Chavez, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: mluisagb@hotmail.com

    2003-07-01

    Since the SSNTD technique (Solid State Nuclear Track Detection) it was discovered it has been used as passive method for the detection of subnuclear particles in great variety of fields of the science. The use of the technique in measurements of {sup 222} Rn in air have already been established implying better methodologies in the exhibition to the environment until their engraving and reading processes. The SSNTD technique is since a method by comparison since the material it can be used a single time, therefore it requires of calibration in one controlled radon atmosphere, using gauged standards. The objective of this work is to show the calibration of the devices used as radon monitors based on SSNTD. The material used as SSNTD is LR-115 Il. The standardization of the parameters used in the exhibition to radon in air, engraving and reading process, its are based on the response of the LR-115 Il, the one arrangement of the device, engraving speed and mainly the calibration factor. They are considered two types of monitors: Open camera and Closed camera, the difference among the calibration factors of both cameras is the percentage of the descendants of radon in the open camera. The standardized parameters are operation voltage of the counting system; temperature, time and concentration of the engraving solution; and thickness. (Author)

  6. Evolution of 222 Rn and chemical species related with eruptive processes of the Popocatepetl volcano

    International Nuclear Information System (INIS)

    Aranda, P.; Ceballos, S.; Cruz, D.; Hernandez, A.; Lopez, R.; Pena, P.; Salazar, S.; Segovia, N.; Tamez, E.

    1997-01-01

    The 222 Rn monitoring in the Popocatepetl volcano was initiated on 1993. At December 21, 1994 it is initiated an eruptive stage in the volcano with gas emission, ashes and the lava dome formation on the crater at middle 1996. During all this time it has been determined radon concentrations on soils with active and passive detectors. In this work the changes in radon contents are reported also the physicochemical parameters in spring water related with the volcanic building associated to the recent activity of the volcano. (Author)

  7. 222Rn content and 234U/238U activity ratio in groundwaters

    International Nuclear Information System (INIS)

    Olguin, M.T.; Segovia, N.; Ordonez, E.; Iturbe, J.L.; Bulbulian, S.; Carrillo, J.

    1990-01-01

    Geochemical radioanalytical studies of ground water were perfomed in the valleys of Villa de Reyes and San Luis Potosi, Mexico. The experiments were designed to measure radon and uranium content and 234 U/ 238 U activity ratio in ground water samples taken from wells in these sites and at the Nuclear Center of Salazar, Mexico. 222 Rn content varied depending on the sample source, reaching a maximum value of 235 pCi/l; uranium concentration results were less than 1 μg/l and 234 U/ 238 U activity ratios were close to equilibrium. (author) 9 refs.; 1 fig.; 1 tab

  8. Fractal analysis and nonlinear forecasting of indoor 222Rn time series

    International Nuclear Information System (INIS)

    Pausch, G.; Bossew, P.; Hofmann, W.; Steger, F.

    1998-01-01

    Fractal analyses of indoor 222 Rn time series were performed using different chaos theory based measurements such as time delay method, Hurst's rescaled range analysis, capacity (fractal) dimension, and Lyapunov exponent. For all time series we calculated only positive Lyapunov exponents which is a hint to chaos, while the Hurst exponents were well below 0.5, indicating antipersistent behaviour (past trends tend to reverse in the future). These time series were also analyzed with a nonlinear prediction method which allowed an estimation of the embedding dimensions with some restrictions, limiting the prediction to about three relative time steps. (orig.)

  9. 222Rn activity concentration differences in groundwaters of three Variscan granitoid massifs in the Sudetes (NE Bohemian Massif, SW Poland)

    International Nuclear Information System (INIS)

    Przylibski, Tadeusz A.; Gorecka, Joanna

    2014-01-01

    Based on research conducted in three Variscan granitoid massifs located within the crystalline Bohemian Massif, the authors confirmed that the higher the degree of their erosional dissection, the smaller the concentration of 222 Rn in groundwaters circulating in these massifs. This notion implies that radon waters and high-radon waters, from which at least some of the dissolved radon should be removed before feeding them as drinking water to the water-supply system, could be expected in granitoid massifs which have been poorly exposed by erosion. At the same time, such massifs must be taken into account as the areas of possible occurrence of radon medicinal waters, which in some countries can be used for balneotherapy in health resorts. Slightly eroded granitoid massifs should be also regarded as very probable radon prone areas or areas of high radon potential. - Highlights: • The concentration of 222 Rn in groundwater depends on the zone of the granitoid massif which is exposed on the ground surface. • The highest 222 Rn concentrations occur in the least eroded granitoid massifs, the lowest in massifs with exposed root parts. • The stronger the erosional dissection of a granitoid massif, the lower 222 Rn concentration in groundwaters in this massif. • Not all granitoid massifs are areas with groundwaters containing high concentrations of 222 Rn. • The least eroded granitoid massifs are radon prone areas with the occurrence of high-radon and radon groundwaters

  10. Seismo-volcanic monitoring at Furnas Volcano (Azores): radon (222Rn) concentration in groundwater

    Science.gov (United States)

    Silva, Catarina; Virgílio Cruz, José; Ferreira, Teresa; Viveiros, Fátima; Freire, Pedro; Allard, Patrick

    2017-04-01

    The Azores archipelago, located in the middle of the North Atlantic Ocean, is composed of nine volcanic islands that formed at the triple junction of the North American, Eurasian and African (Nubian) tectonic plates. These volcanic islands were the sites of several eruptions and destructive earthquakes since human settlement in the 15th century. S. Miguel Island, the largest and most densely populated island of the Azores, hosts three active strato-volcanoes with calderas. Furnas Volcano is one of these. Its eruptive activity has been essentially explosive, involving magmas with trachytic (s.l.) composition. In the last 5000 years at least 10 explosive eruptions occurred inside the caldera of Furnas. The last one occurred in 1630 and was subplinian in character. Since then an intense hydrothermal activity has persisted, involving four main fumarolic fields, thermal springs, CO2-rich springs, several soil diffuse degassing areas (CO2 and 222Rn), as well as occasional hydrothermal explosions. In the past decade we have developed a radon survey of Furnas hydrothermal manifestations. Here we report on the radon survey of twelve water springs, located inside the caldera, and representative of the different water types encountered at the volcano (orthothermal, thermal and CO2-rich springs). Bimonthly sampling and determination of radon activity and water temperature was performed in the selected springs between years 2007 and 2011. At each sampling point two water samples were collected for radon dosing in laboratory with the RAD7 equipment. A decay correction was applied to each sample. The average radon activities were found to vary between 1.15 Bq/L and 29.77 Bq/L, while water temperatures ranged between 16.5 °C and 76.2 °C. As a whole radon activities inversely correlate with water temperature, with orthothermal springs showing higher radon activity than thermal springs. Temporal variations in both parameters appear to be mainly determined by seasonal variations of

  11. Determination of {sup 222}Rn and its physico-chemical and biological characteristics in aquifers of Toluca valley; Determinacion de {sup 222}Rn y caracteristicas fisicoquimicas y biologicas en acuiferos del Valle de Toluca

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, A.; Aranda, P.; Ceballos, S.; Cruz, D.; Jauregui, B.; Lopez, R.; Pena, P.; Salazar, S.; Segovia, N.; Tamez, E. [Instituto nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    In this work it is realized a geochemical study which includes the evaluation of {sup 222} Rn concentration in drinking water wells at Toluca city and a spring water of Almoloya de Juarez municipality at State of mexico. the same is studied about evolution of {sup 222} Rn concentration in water of the hydrating which supply it to those wells. the geochemical evaluation also covers the determination of major and minor elements or trace and the biological analysis of water. The study includes two seasonal cycles, the low water mark one and other the rainy for being able to evaluate the aquifers reloading effects in the water composition. (Author)

  12. Measurements of {sup 222} Rn in the indoor of dwellings in the Argentinean Republic; Mediciones de {sup 222} Rn en el interior de viviendas de la Republica Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Canoba, A.; Lopez, F. [Autoridad Regulatoria Nuclear, Av. Del Libertador 8250 Ciudad de Buenos Aires (1429) (Argentina)]. e-mail: acanoba@cae.arn.gov.ar

    2006-07-01

    The {sup 222} Rn is responsible for approximately half of the dose in the population resultant of the exposure to natural radiation. Most of this dose comes from the inhalation of the offspring of the {sup 222} Rn, and these doses they are specially important in set closed. The concentration of gas radon has been measured in housings of different cities of the Argentinean Republic. The elected cities are representative of the different geologic areas of our territory. For this its were used as detecting measurement method of nuclear tracks, electret detectors and detectors based on the adsorption in activated coal. Its were analyzed a total of 2689 housings from 1983 to the date. The average value of the radon concentration obtained starting from the 2689 monitored housings was of 41.6 Bq.m{sup -3}. The effective annual dose calculated starting from this radon concentration, using a dosimetric factor of 25 {mu}Sv.a{sup -1} (Bq.m{sup -3}), which assumes an equilibrium factor of 0.4, was of 1.04 mSv. Also, with the objective of determining the dose in form more exact, during the year 2000 it put on to point a passive technique for the simultaneous measurement such the radon concentration like of the equilibrium factor. This technique uses in oneself device two detectors of nuclear traces. The average value obtained starting from 204 monitored housings by this method of simultaneous measurement turns out to be 47.1 Bq.m{sup -3} and 0.36 the equilibrium factor, being obtained a value of effective annual dose of 1.38 mSv. It fits to highlight that are very few the values above 200 Bq.m{sup -3} and in any case the 300 Bq.m{sup -3} is overcome. Analyzing the average equilibrium factor measured of 0.36, it was concluded that having assumed an equilibrium factor of 0.4 was adequate, for what for great measurement campaigns it can continue using the simple method that determines only the radon concentration. Comparing the obtained results by both methods, although the first

  13. Indoor "2"2"2Rn concentration in the exhibition and storage rooms of Polish geological museums

    International Nuclear Information System (INIS)

    Długosz-Lisiecka, Magdalena; Krystek, Marcin; Raczyński, Paweł; Głuszek, Ewa; Kietlińska-Michalik, Barbara; Niechwedowicz, Mariusz

    2017-01-01

    The radon exhaled from radioactive mineral collections exhibited in five Polish geological museums may influence its total indoor concentration. Radon concentrations measured in the exhibition halls do not pose a risk for visitors or museum staff. However, air exceeding the action limit for workers (equal to 300 Bq/m"3) was noted in the storage rooms of two museums. Significant"2"2"2Rn activity concentrations equal to more than ~300 kBq/m"3were measured inside lead containers where radioactive minerals were stored. - Highlights: • In this "2"2"2Rn radionuclide measurements in 5 Polish geological museums have been done. • The review of "2"2"2Rn activity in the air in areas containing radioactive geological collections is not a routine protocol, and is not included in the national radon monitoring program. • Therefore the radiological exposure for museum staff resulting from inhalation of gaseous radon and its products has been including.

  14. Measuring techniques for environmental sup 3 H, sup 14 C and sup 222 Rn by liquid scintillation counter

    Energy Technology Data Exchange (ETDEWEB)

    Takata, Shigeru; Saito, Masaaki (Tokyo Metropolitan Isotope Research Center (Japan))

    1991-02-01

    Measuring techniques for environmental {sup 3}H, {sup 14}C and {sup 222}Rn with a liquid scintillation counter have been studied. {sup 3}H in environmental water was enriched by electrolysis and measured with a low background liquid scintillation counter. By this technique, {sup 3}H concentration of ground water, river water, sea water and rain water at Tokyo was founded to be 0.1 {approx} 2.5 Bq/1. {sup 14}C in taurine and ethyl-alcohol was measured directly liquid scintillation counter. By this {sup 14}C measuring, natural products, contain low level {sup 14}C, were distinguished from synthesised products contain no {sup 14}C. {sup 222}Rn in toluene extracted from environmental water or air was measured by scintillation pulse interval analysis method. By this technique, {sup 222}Rn was able to be measured under very low background counting rate, 0.03cpm, and high efficiency. (author).

  15. Improved automated analysis of radon (222Rn) and thoron (220Rn) in natural waters.

    Science.gov (United States)

    Dimova, Natasha; Burnett, William C; Lane-Smith, Derek

    2009-11-15

    Natural radon ((222)Rn) and thoron ((220)Rn) can be used as tracers of various chemical and physical processes in the environment. We present here results from an extended series of laboratory experiments intended to improve the automated analysis of (222)Rn and (220)Rn in water using a modified RAD AQUA (Durridge Inc.) system. Previous experience with similar equipment showed that it takes about 30-40 min for the system to equilibrate to radon-in-water concentration increases and even longer for the response to return to baseline after a sharp spike. While the original water/gas exchanger setup was built only for radon-in-water measurement, our goal here is to provide an automated system capable of high resolution and good sensitivity for both radon- and thoron-in-water detections. We found that faster water flow rates substantially improved the response for both isotopes while thoron is detected most efficiently at airflow rates of 3 L/min. Our results show that the optimum conditions for fastest response and sensitivity for both isotopes are at water flow rates up to 17 L/min and an airflow rate of 3 L/min through the detector. Applications for such measurements include prospecting for naturally occurring radioactive material (NORM) in pipelines and locating points of groundwater/surface water interaction.

  16. Assessment of 222Rn occupational exposure at IPEN nuclear materials storage site, SP, Brazil

    International Nuclear Information System (INIS)

    Caccuri, Lilian Saueia

    2007-01-01

    In this study it was assessed the occupational exposure to 222 Rn at IPEN, SP, Brazil, nuclear materials storage site through the committed effective dose received by workers exposed to this radionuclide. The radiation dose was calculated through the radon concentrations at nuclear materials storage site. Radon concentrations were determined by passive detection method with solid state nuclear detectors (SSNTD). The SSNTD used in this study was the polycarbonate Makrofol E; each detector is a small square plastic of 1 cm 2 , placed into a diffusion chamber type KFK. It was monitored 14 points at nuclear materials storage site and one external point, over a period of 21 months, changing the detectors every three months, from December 2004 to September 2006. The 222 Rn concentrations varied from 196 ± 9 and 2048 ± 81 Bq·m -3 . The committed effective dose due to radon inhalation at IPEN nuclear materials storage site was obtained from radon activity incorporated and dose conversion factor, according to International Commission on Radiological Protection procedures. The effective committed dose received by workers is below 20 mSv·y -1 . This value is suggested as an annual effective dose limit for occupational exposure by ICRP 60. (author)

  17. {sup 222}Rn determination in water and brine samples using liquid scintillation spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Thiago C.; Oliveira, Arno H., E-mail: oliveiratco2010@gmail.com [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte (Brazil). Departamento de Engenharia Nuclear; Monteiro, Roberto P.G.; Moreira, Rubens M., E-mail: rpgm@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN-CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Liquid scintillation spectrometry (LSC) is the most common technique used for {sup 222}Rn determination in environmental aqueous sample. In this study, the performance of water-miscible (Ultima Gold AB) and immiscible (Optiscint) liquid scintillation cocktails has been compared for different matrices. {sup 241}Am, {sup 90}Sr and {sup 226}Ra standard solutions were used for LSC calibration. {sup 214}Po region was defined as better for both cocktails. Counting efficiency of 76 % and optimum PSA level of 95 for Ultima Gold AB cocktail, and counting efficiency of 82 % and optimum PSA level of 85 for Optiscint cocktail were obtained. Both cocktails showed similar results when applied for {sup 222}Rn activity determination in water and brine samples. However the Optiscint is recommended due to its quenching resistance. Limit of detection of 0.08 and 0.06 Bq l{sup -1} were obtained for water samples using a sample:cocktail ratio of 10:12 mL for Ultima Gold AB and Optiscint cocktails, respectively. Limit of detection of 0.08 and 0.04 Bq l{sup -1} were obtained for brine samples using a sample:cocktail ratio of 8:12 mL for Ultima Gold AB and Optiscint cocktails, respectively. (author)

  18. 222Rn determination in water and brine samples using liquid scintillation spectrometry

    International Nuclear Information System (INIS)

    Oliveira, Thiago C.; Oliveira, Arno H.

    2017-01-01

    Liquid scintillation spectrometry (LSC) is the most common technique used for 222 Rn determination in environmental aqueous sample. In this study, the performance of water-miscible (Ultima Gold AB) and immiscible (Optiscint) liquid scintillation cocktails has been compared for different matrices. 241 Am, 90 Sr and 226 Ra standard solutions were used for LSC calibration. 214 Po region was defined as better for both cocktails. Counting efficiency of 76 % and optimum PSA level of 95 for Ultima Gold AB cocktail, and counting efficiency of 82 % and optimum PSA level of 85 for Optiscint cocktail were obtained. Both cocktails showed similar results when applied for 222 Rn activity determination in water and brine samples. However the Optiscint is recommended due to its quenching resistance. Limit of detection of 0.08 and 0.06 Bq l -1 were obtained for water samples using a sample:cocktail ratio of 10:12 mL for Ultima Gold AB and Optiscint cocktails, respectively. Limit of detection of 0.08 and 0.04 Bq l -1 were obtained for brine samples using a sample:cocktail ratio of 8:12 mL for Ultima Gold AB and Optiscint cocktails, respectively. (author)

  19. Study of 222Rn emanation levels present in naturally occurring radioactive materials - NORM

    International Nuclear Information System (INIS)

    Miranda, Marcia Valeria F.E. Sa; Crispim, Verginia Reis; Lima, Clara Teresa S.

    2009-01-01

    The presence of Naturally Occurring Radioactive Material (NORM), contaminating oil and gas installations, is usual in the petroleum industry, and can be severe enough to expose the workers to elevated levels of radiation. The segregation of contaminated residues although necessary, is still a problem without a satisfactory solution. Currently, the most practical and economic option for discarding this material is to stock it in areas of the installation with controlled access. Certain equipment used in the petroleum industry has scale and sludge that could be associated to important levels of radioactivity. Typically, the scales are mixtures of carbonate and sulphate minerals, such as barite (BaSO 4 ), that easily incorporate 226 Ra and 228 Ra in their structures. The objective of this work was to measure the emanations of the radon present in NORM samples, via diffusion chambers containing a nuclear track detector (CR-39). The images of α particle tracks emanated by 222 Rn registered on CR-39 were observed with a Nikon E400 optic microscope and captured by a Nikon Coolpix digital camera and then stored in a database, to later count the tracks using the computational program, Image Pro plus. Since the number of those tracks resulted proportional to the emanation rate of 222 Rn this methodology allowed the comparison of contamination levels in analyzed samples. (author)

  20. Exposures to 222Rn and its progeny derived from implanted 210Po activity

    International Nuclear Information System (INIS)

    Nikezic, D.; Yu, K.N.

    2006-01-01

    The Jacobi room model was applied to study the relative contributions from the unattached and attached fractions to the implanted activity of 210 Po. It was found that under normal conditions, about 85% of the implantation was due to the unattached fraction. Sensitivity analysis was performed to identify the most important factors that influence the deposition and implantation of radon progeny. The main factors affecting the incorporation of 210 Po are the attachment rate, deposition rate of unattached progeny and the surface to volume ratio of the room. The calibration curves, which related the 210 Po activity per unit surface area to the concentrations of 222 Rn and of the radon progeny, were determined as functions of exposure times. The implanted activity is found to distribute close to a lognormal distribution. For an exposure of 20 years, the distribution has a geometric standard deviation of 2.2 and a geometric mean of 0.023Bq/m 2 /(Bq/m 3 ). The last value is considered as the calibration coefficient of the glass response in terms of the implanted 210 Po activity per unit surface area per unit concentration of 222 Rn for an exposure period of 20 years

  1. Practical difficulties in determining 222Rn flux density in underground uranium mines

    International Nuclear Information System (INIS)

    Bigu, J.

    1991-01-01

    Radon-222 flux density, J, has been determined in a number of locations in an underground U mine. Measurements were conducted using the Two-Point Measurement (2PM) method, consisting of measuring the 222Rn concentration at two different points a distance apart within a given section of the mine. Several mine models were used for determining J by the above method. The 2PM method is sensitive to sources and sinks of 222Rn other than mine walls, as well as mining operations and mining activities of a diverse nature, and to local variations in airflow conditions. Because of this, J obtained by the 2PM method represents an 'apparent' flux density. Significant differences were found in the flux density calculated according to different mine models. In addition, J measurements using the flux 'can' method were also carried out in mine walls and compared with the values obtained by the 2PM method. Wide discrepancies between the two methods were found. The practical and theoretical difficulties in determining J are discussed

  2. 222Rn determination in some thermal baths of a central eastern Italian area

    International Nuclear Information System (INIS)

    Desideri, D.; Bruno, M.R.; Roselli, C.

    2004-01-01

    Some recent Italian laws, based on the Euratom Directive 26/96, introduce the obligation of monitoring the exposition to natural radioactivity in particular worksites (thermal baths, mines, basements, etc.). Results of 222 Rn measurements in some thermal baths of Rimini and Pesaro-Urbino provinces (Central Eastern Italy), by Radosys-2000, a complete set suitable to radon concentration measurements with CR-39 plastic alpha-track detectors are reported. Some areas where radon could accumulate (bathing, reaction, muddy, inhalation, insufflation rooms and swimming pools) were selected for the investigation. The dosimeters have been exposed for 98 days. The results show that 222 Rn concentrations are very low in the considered thermal baths (7-71 Bq x m -3 ). Moreover, no difference was observed between the concentrations measured in the therapy rooms (bathing, muddy, inhalation and insufflation rooms, swimming pools) and in the normal areas (passages, reaction rooms, dressing rooms, etc.). The calculated dose contribution to workers was about one tenth of the legally suggested value. (author)

  3. A survey of 222Rn in drinking water in mexico city

    International Nuclear Information System (INIS)

    Vasquez-Lopez, C.; Zendejas-Leal, B. E.; Golzarri, J. I.; Espinosa, G.

    2011-01-01

    In Mexico City there are more than 22 millions of inhabitants (10 in the metropolitan area and 12 in the suburban zone) exposed to drinking water. The local epidemiological authorities recognised that exposure to radon contaminated drinking water is a potential health hazard, as has been considered worldwide. The United States Environmental Protection Agency has proposed a limit of 11.1 Bq l -1 for the radon level in drinking water. In Mexico a maximum contamination level of radon in drinking water has not yet even considered. In this work, a 222 Rn study of drinking water in Mexico City has revealed a range of concentrations from background level to 3.8 Bq l -1 . 222 Rn was calculated using a portable degassing system (AquaKIT) associated with an AlphaGUARD measuring system. Samples from 70 wells of the water system of the south of the Valley Basin of Mexico City and from houses of some other political administrative divisions of Mexico City were taken. (authors)

  4. 222Rn determination in mineral waters from the Pocos de Caldas Plateau in Brazil

    International Nuclear Information System (INIS)

    Taddei, M.H.T.; Silva, N.C.; Cipriani, M.

    2002-01-01

    It is estimated that 50% of the radioactive effective dose equivalent to man comes from radon and its radioactivity daughters. The main 222 Rn sources are the soils, building materials and potable waters. There is an especial interest in spas waters with high natural radioactivity. It's considered that the use of these waters as drinking waters is a significant radiation exposure factor, and it is worthwhile to assess the consequent dose. Such estimation has been made for the Pocos de Caldas Plateau, which is a region of high natural radioactivity, from volcanic origin, containing several spas (Aguas da Prata, Caldas, Pocos de Caldas and Andradas). The 222 Rn content was determined in 23 spring waters in Pocos de Caldas and neighboring cities. In water sampling, modified Marinelli flasks were used. The determinations were effected with a high resolution gamma ray spectrometer. High concentration variations were observed in the collected mineral waters, the highest values having been found in Fonte Villela's waters, in Aguas da Prata town (926 Bq/l); Grande Hotel's in Caldas Town (420 Bq/l) and COLAB's in Pocos de Caldas region (289 Bq/l). The annual whole body effective dose equivalent estimate for adult due to water ingestion, using the Crowford-Brown's biokinetic model's adult dose conversion factors, was higher than 1 mSv/year in 61% of the analyzed waters. (author)

  5. Study of the emanation levels of 222Rn present in Naturally Occurring Radioactive Materials - NORM

    International Nuclear Information System (INIS)

    Miranda, Marcia Valeria de Fatima da Encarnacao Sa

    2009-01-01

    The presence of Naturally Occurring Radioactive Material (NORM), contaminating oil and gas facilities, is a common fact in the petroleum industry, and can be severe enough to expose the workers to elevated levels of radiation. Thus, contaminated residues need to be segregated but, this is still a problem without a satisfactory solution. Currently, the most practical and economic option for discarding this material is to stock it in areas of the facility whose access is controlled. Certain equipment used in the petroleum industry has scale and sludge that could be associated to important levels of radioactivity. Typically, the scale is a mixture of carbonate and sulphate minerals, such as barite (BaSO 4 ), that easily incorporates 226 Ra and 228 Ra in its structures. The objective of this work was to measure the emanations of the radon present in these NORM samples, via diffusion chambers containing a nuclear track detector (CR-39). The images of particle alpha tracks emanated by 222 Rn registered on CR-39 were observed with a Nikon E400 optic microscope and captured by a Nikon Coolpix digital camera and then stored in a database, to later count the tracks using the computational program, Image Pro plus. Being that the emanation rate of 222 Rn was proportional to the number of these tracks the methodology permitted the comparison of contamination levels of the analyzed samples. (author)

  6. Attached, unattached fraction of progeny concentrations and equilibrium factor for dose assessments from {sup 222}Rn and {sup 220}Rn

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Parminder; Saini, Komal; Bajwa, Bikramjit Singh [Guru Nanak Dev University, Department of Physics, Amritsar, Punjab (India); Mishra, Rosaline; Sahoo, Bijay Kumar [Bhabha Atomic Research Centre, Radiological Physics and Advisory Division, Mumbai (India)

    2016-08-15

    In this study, measurements of indoor radon ({sup 222}Rn), thoron ({sup 220}Rn) and their equilibrium equivalent concentration (EEC) were carried out in 96 dwellings from 22 different villages situated in Hamirpur district, Himachal Pradesh, India, by using LR-115 type II-based pinhole twin cup dosimeters and deposition-based progeny sensors (DRPS/DTPS). The annual average indoor {sup 222}Rn and {sup 220}Rn concentrations observed in these dwellings were 63.82 and 89.59 Bq/m{sup 3}, respectively, while the average EEC (attached + unattached) for {sup 222}Rn and {sup 220}Rn was 29.28 and 2.74 Bq/m{sup 3}. For {sup 222}Rn (f{sub Rn}) and {sup 220}Rn (f{sub Tn}), the average values of unattached fraction were 0.11 and 0.09, respectively. The equilibrium factors for radon (F{sub Rn}) and thoron (F{sub Tn}) varied from 0.12 to 0.77 with an average of 0.50, and from 0.01 to 0.34 with an average of 0.05, respectively. The annual inhalation dose due to mouth and nasal breathing was calculated using dose conversion factors and unattached fractions. The indoor annual effective doses for {sup 222}Rn (AEDR) and {sup 220}Rn (AEDT) were found to be 1.92 and 0.83 mSv a{sup -1}, respectively. The values of {sup 222}Rn/{sup 220}Rn concentrations and annual effective doses obtained in the present study are within the safe limits as recommended by the International Commission on Radiological Protection for indoor dwelling exposure conditions. (orig.)

  7. Determination of 222Rn and its physico-chemical and biological characteristics in aquifers of Toluca valley

    International Nuclear Information System (INIS)

    Hernandez, A.; Aranda, P.; Ceballos, S.; Cruz, D.; Jauregui, B.; Lopez, R.; Pena, P.; Salazar, S.; Segovia, N.; Tamez, E.

    1997-01-01

    In this work it is realized a geochemical study which includes the evaluation of 222 Rn concentration in drinking water wells at Toluca city and a spring water of Almoloya de Juarez municipality at State of mexico. the same is studied about evolution of 222 Rn concentration in water of the hydrating which supply it to those wells. the geochemical evaluation also covers the determination of major and minor elements or trace and the biological analysis of water. The study includes two seasonal cycles, the low water mark one and other the rainy for being able to evaluate the aquifers reloading effects in the water composition. (Author)

  8. A preliminary investigation of 222Rn and 220Rn levels in non-uranium mines in China

    International Nuclear Information System (INIS)

    Shang Bing; Cui Hongxing; Wu Yunyun; Zhang Qingzhao; Su Xu

    2008-01-01

    Objective: To measure levels of 222 Rn and 220 Rn in typical non-uranium mines, China, and to estimate dose from the occupational radon exposure in the miners. Methods: Using typical sampling scheme, 44 mines were selected in 12 provinces, which can be classified into 4 categories and 17 types of mines. The radon-thoron discriminative detectors were used to measure 222 Rn and 220 Rn concentrations in mines. Result: The concentration of 222 Rn or 220 Rn was log-normally distributed. The arithmetic mean (AM) concentration and geometric mean (GM) concentration of 222 Rn and 220 Rn in 25 metal mines (n=147) were estimated to be (1211 ±2359) Bq/m 3 (AM) and (311 ± 5.5) Bq/m 3 (GM), and (269 ±700) Bq/m 3 (AM) and (71 ± 4.4)Bq/m 3 (GM), respectively. The mean concentrations of 222 Rn and 220 Rn in 18 non-metal mines (n=118) were (98 ± 207) Bq/m 3 (AM) and(55 ± 2.5) Bq/m 3 (GM), and (60 ± 76) Bq/m 3 (AM) and (38 ± 2.4) Bq/m 3 (GM) respectively. In total, we measured 222 Rn concentration in 44 underground mines, 6 of them, accounted for 15%, with the mean radon concentration exceeding 1000 Bqm -3 (limit of workplace in China). Approximately 7% of radon concentration in mines measured were higher than 3700 Bq/m 3 (current limit in uranium mine in China), some points even exceeded 10 000 Bq/m 3 . Based on this typical measurements, the equilibrium factor for 222 Rn was estimated to be 0.33 ± 0.15 in underground mines and 0.47 ±0.18 in nearby houses. Equilibrium factor for 220 Rn ranged from 0.001 to 0.032. Using the data obtained in this typical survey, the average annual effective dose of underground miners exposed to radon and thoron was estimated to be 8.15 mSv/a. Conclusions: High levels of 222 Rn exists in metal mines, such as copper, tin, lead and zinc, gold, and aluminum mines among others. More study and administrative measures are needed to address the radiation protection of workers occupationally exposed to high radon in mines. (authors)

  9. 222Rn studies and mapping in the city of Curitiba - Brazil

    International Nuclear Information System (INIS)

    Correa, Janine Nicolosi; Fior, Loriane; Paschuk, Sergei A.; Schelin, Hugo R.; Pecequilo, Brigitte R. S.; Paula Melo, Vicente de

    2008-01-01

    This work describes radon monitoring performed in cooperation between the Laboratory of Ionizing Radiations of the Federal University of Technology - Parana (UTFPR), the Institute of Nuclear and Energetic Researches (IPEN) and the Institute of Radiation Protection and Dosimetry (IRD), from the Brazilian Nuclear Energy Commission (CNEN), during the last two years. For 222 Rn concentration measurements related to different construction materials as well as for the studies of radon emanation and its reduction, the sealed cell chambers, of approximately 60 x 60 cm 2 , was built using ceramic and concrete blocks. This construction was performed within a protected and isolated laboratory environment to maintain the air humidity and temperature stable. These long term measurements have been performed using polycarbonate alpha track passive detectors. The exposure time was set to 15 days considering previous calibration performed at IRD, where a efficiency of 70% was obtained for the density of alpha particle tracks about 13.8 cm -2 per exposure day and per kBq/m 3 of radon activity concentration. The chemical development of the alpha tracks was achieved by electrochemical etching. The track identification and counting were done using a code based on the MATLAB Image Processing Toolbox. The cell chambers were built following four main steps: 1) assembling the walls using the blocks and mortar; 2) plaster installation; 3) wall surface finishing using lime; 4) wall surface insulation by paint. By comparison between three layers installed at the masonry walls from concrete and ceramic blocks, it was concluded that only wall painting with acrylic varnish attended the expectation and reduced the radon emanation flow by a factor of approximately 2.5. The construction materials were submitted to the instant measurements of radon concentration using a ALPHA GUARD Professional detector. The samples of the construction materials were stored inside an acrylic container (sealed up

  10. Comparison of outdoor activity size distributions of 220 Rn and 222 Rn progeny and their Influences on lung dosimetry distributions

    International Nuclear Information System (INIS)

    Mohamed, A.; El-Hussein, A.; Ahmed, A.

    2005-01-01

    In the case of internally deposited radionuclides, direct measurement of the energy absorbed from ionizing radiation emitted by the decaying radionuclides is rarely, if ever, possible. Therefore, one must rely on dosimetric models to obtain estimates of the spatial and temporal patterns of energy deposition in human lung. T These models always need some information about the parameters of activity size distributions of thoron and radon progeny. In the present work, the attached and unattached activity size distributions of thoron and radon progeny were measured in outdoor air of El-Minia, Egypt. The attached samples were collected using a low pressure Berner cascade impactor technique, while a constructed screen diffusion b attery was used for collecting the unattached samples. Most of the attached activities for 222 Rn and 220 Rn progeny were associated with the aerosol particles of the accumulation mode. The activity size distribution of thoron progeny was found to be shifted to slightly smaller particle size, compared to radon progeny. An analytical method has been developed to compute the local energy deposition of 2l2 Bi alpha particles in a target volume of 1 jam spheres located at different depths in bronchial epithelium. In order to reach the target, alpha particles travel either through tissue alone (near-wall dose) or through air and tissue (far-wall dose). It was found that the contribution of near-wall dose is higher than that of the far wall dose. While the depth-dose distributions for nuclides uniformly distributed within the epithelium are practically constant with

  11. Effects of vegetation, a clay cap and environmental variables on 222Rn fluence rate from reclaimed U mill tailings

    International Nuclear Information System (INIS)

    Morris, R.C.; Fraley, L. Jr.

    1989-01-01

    We measured 222 Rn fluence rate and several environmental variables on two plots with U mill tailings buried beneath 30 cm of overburden and 20 cm of topsoil. An additional 30 cm of clay covered the tailings on one plot and each plot was subdivided into bare soil and vegetated subplots. We used linear correlation, two-way ANOVA and stepwise multiple regression to analyze the effects of the plot characteristics and the environmental variables on 222 Rn fluence rate. The most important effect on 222 Rn fluence rates from these plots was the combination of a clay cap and a vegetated surface. The mean annual fluence rate from the plot having both of these characteristics (520 +/- 370 mBq m-2 s-1) was over three times that of the vegetated plot without a clay cap (170 +/- 130 mBq m-2 s-1) and 18 times that of the bare plot with a clay cap (29 +/- 13 mBq m-2 s-1). The interaction effect may have been due to the growth of roots in the moist clay and active transport of dissolved 222 Rn to the surface in water. This speculation is supported by the observation that on vegetated plots with a clay cap, moisture in the clay enhanced the fluence rate

  12. Estimated doses related to 222Rn concentration in bunker for radiotherapy and storage of radioisotopes

    International Nuclear Information System (INIS)

    Mestre, Freddy; Carrizales-Silva, Lila; Sajo-Bohus, Laszlo; Diaz, Cruz

    2013-01-01

    It was done a survey in radiotherapy services underground hospitals and clinics of Venezuela and Paraguay in order to estimate the concentrations of radon and its possible consequences on worker occupational exposure. Passive dosimeters were used to assess nuclear traces (NTD type CR-39®). The concentration of 222 Rn is determined based on the density of traces using the calibration coefficient of 1 tr/cm 2 equivalent to 0,434 Bqm -3 per month of exposure. Assuming the most likely environmental conditions and the dose conversion factor equal to 9.0 x 10 -6 mSv h -1 by Bqm -3 , it was determined the average values and estimated the possible risks to health that are on average 3.0 mSva -1 and 150 micro risk cancer

  13. Comparison of methods and instruments for 222Rn/220Rn progeny measurement

    International Nuclear Information System (INIS)

    Liu Yanyang; Shang Bing; Wu Yunyun; Zhou Qingzhi

    2012-01-01

    In this paper, comparisons were made among three methods of measurement (grab measurement, continuous measurement and integrating measurement) and also measurement of different instruments for a radon/thoron mixed chamber. Taking the optimized five-segment method as a comparison criterion, for the equilibrium-equivalent concentration of 222 Rn, measured results of Balm and 24 h integrating detectors are 31% and 29% higher than the criterion, the results of Wl x, however, is 20% lower; and for 220 Rn progeny, the results of Fiji-142, Kf-602D, BWLM and 24 h integrating detector are 86%, 18%, 28% and 36% higher than the criterion respectively, except that of WLx, which is 5% lower. For the differences shown, further research is needed. (authors)

  14. Time variation of 222Rn concentration and gamma level in a half-basement room

    International Nuclear Information System (INIS)

    Iimoto, Takeshi; Eguchi, Hoshio; Kosako, Toshiso; Sugiura, Nobuyuki

    1998-01-01

    Correlation between 222 Rn (radon) concentration and gamma level in a half-basement has been discussed. In order to decrease the background count of a whole-body counter (WBC), a ventilation blower of 72 m 2 h -1 was installed. The device succeeded in a big reduction of radon concentration in the half-basement and then the background of WBC (NaI(Tl)) decreased to the 76.5% of the saturated value. Through a radon saturation test the exhalation rate of radon from concrete wall was estimated as 2.1 Bqm -2 h -1 by a simple model calculation. In addition, through a ventilation test, the procedure was analyzed by another simple model. (author)

  15. Doses from 222Rn, 226Ra, and 228Ra in groundwater from Guarani aquifer, South America.

    Science.gov (United States)

    Bonotto, D M

    2004-01-01

    Groundwater samples were analysed for 222Rn, 226Ra, and 228Ra in Guarani aquifer spreading around 1 million km2 within four countries in South America, and it was found that their activity concentrations are lognormally distributed. Population-weighted average activity concentration for these radionuclides allowed to estimate a value either slightly higher (0.13 mSv/year) than 0.1 mSv for the total effective dose or two times higher (0.21 mSv/year) than this limit, depending on the choice of the dose conversion factor. Such calculation adds useful information for the appropriate management of this transboundary aquifer that is socially and economically very important to about 15 million inhabitants living in Brazil, Argentina, Uruguay and Paraguay.

  16. E-perm radon monitors for determining waterborne concentrations of dissolved in radon 222Rn

    International Nuclear Information System (INIS)

    Jester, W.A.; Kotrappa, P.

    1989-01-01

    This paper describes a simple and relatively inexpensive method in which E-Perm radon monitors are used to determine the concentration of dissolved 222 Rn in drinking water. This procedure takes advantage of E-Perm's ability to accurately measure the integral radon exposure under conditions of high humidity. The method was evaluated against the liquid scintillation procedure recommended by the U.S. Environmental Protection Agency (EPA) and was found to give excellent agreement. An E-perm is an electret ion chamber that consists of a small chamber constructed from a conducting plastic and having an electret at its base and a filtered air inlet at the top. The technique described in this paper takes advantages of E-Perm's insensitivity to high humidity

  17. Seasonal variations of 222Rn concentrations in the air of a tunnel located in Nagano City

    International Nuclear Information System (INIS)

    Muramatsu, H.; Tashiro, Y.; Hasegawa, N.; Misawa, C.; Minami, M.

    2000-01-01

    The survey of 222 Rn concentrations in the air of tunnels constructed during World War II at Nagano City has been performed using a solid-state nuclear track detector technique. Concentrations of several thousands Bq m -3 were observed at inner most areas of the tunnel. A seasonal variation was clearly observed; in summer, several times higher concentrations than in winter were observed, which may be due to a stack effect induced by the temperature difference between the tunnel air and the outside air in each season. The concentrations of radon in the tunnel air decrease exponentially towards the openings of the tunnel, which indicates that the radon concentration in the tunnel is basically governed by diffusion and mixing of radon gas with air. (author)

  18. Doses from 222Rn, 226Ra, and 228Ra in groundwater from Guarani aquifer, South America

    International Nuclear Information System (INIS)

    Bonotto, D.M.

    2004-01-01

    Groundwater samples were analysed for 222 Rn, 226 Ra, and 228 Ra in Guarani aquifer spreading around 1 million km 2 within four countries in South America, and it was found that their activity concentrations are lognormally distributed. Population-weighted average activity concentration for these radionuclides allowed to estimate a value either slightly higher (0.13 mSv/year) than 0.1 mSv for the total effective dose or two times higher (0.21 mSv/year) than this limit, depending on the choice of the dose conversion factor. Such calculation adds useful information for the appropriate management of this transboundary aquifer that is socially and economically very important to about 15 million inhabitants living in Brazil, Argentina, Uruguay and Paraguay

  19. Relationship of 220Rn and 222Rn progeny levels in Canadian underground U mines

    International Nuclear Information System (INIS)

    Bigu, J.

    1988-01-01

    Radon-222 and 220 Rn progeny are found in some Canadian underground U mines. Because both can contribute to lung dose, their experimental determinations are important. The relationship between 222 Rn progeny Working Level [WL(Rn)] and 220 Rn progeny Working Level [WL(Tn)] has been investigated in U mines. Experimental measurements extended from 1981 to 1986 and consisted of about 700 measurements of each WL(Rn) and WL(Tn). The data were analyzed by standard linear and power-function regression analysis. A power-function relationship between WL(Rn) and WL(Tn) seemed to fit the experimental data best. The relationship obtained permits the calculation of WL(Tn) from experimental values of WL(Rn). The relationship is useful for lung-dose-calculation purposes and in mine-ventilation-engineering calculations

  20. Distribution of 222Rn in dwellings around proposed uranium mining site at Rohil, Rajasthan

    International Nuclear Information System (INIS)

    Jha, V.N.; Kumar, Rajesh; Singh, M.K.; Patnaik, R.L.; Sahoo, S.K.; Jha, S.K.; Tripathi, R.M.

    2018-01-01

    Prior to commissioning of uranium ore mining and processing facility baseline radiological monitoring vis-a-vis public exposure assessment is required. Such information are utilized for developing control measures during operational phases to ascertain the minimal impact on the surrounding areas. Among the various pathways the inhalation component far exceeds the other component in the natural background of a region. Further, in inhalation component also the contribution of 222 Rn is almost 50%. The main sources of indoor radon are geological features, soil characteristics, construction materials of the dwellings, water utilization pattern, use of natural cooking gas, climatological/weather variables. As part of preliminary radiological assessment exercise twenty three dwellings were selected in this region comprising of different types of construction design/materials and passive radon dosimeters were provided of evaluation of radon level and inhalation exposure. The results presented in the text are part of the said radiological assessment exercise

  1. Continuous 222Rn measurements in water to perform a hydrograph separation

    International Nuclear Information System (INIS)

    Hofmann, H.; Kies, A.; Tosheva, Z.

    2004-01-01

    To get information about the different components of runoff before, during and after heavy rain events, micro catchments were selected to perform hydrograph separations using the radioactive noble gas 222 Rn and the stable isotope 18 O as natural occurring, conservative tracers. These tracers help to separate 'pre event', 'event', and 'post event' water in the total runoff. The selected micro basins are situated in the western part of Luxembourg and belong to the Attert River catchment area. Our investigations are a part of the project 'Cycleau' which is studying risk assessments in the Attert River area. By combining the databases great opportunities for comparison were realized. So far the catchment areas have been studied for two years. Continuous monitoring radon detectors were installed at selected measuring points, which were important for the different flow regimes. Along with the detectors precision thermometers, conductivity instruments, CO 2 -detectors, flow meter, v-notches, and automatic sampler for chemical analysis were set up. Besides the continuous measurements for 222 Rn, point samples were taken for liquid scintillation analysis (LCS). Single rain events will have been sampled and measured intensively for 222 Rn (LCS) and 18 O in two to three days field campaigns, for a comparison of the continuous method with the 18 O results and to strengthen our data by the end of march 2004. During the first year of this study instrument testing and evaluation was performed. Different radon monitor units were examined to find instruments that work best under field conditions. Additionally, separate units had to be constructed for a degassing of the solved gases out of the water, because the instruments for radon measuring were constructed for radon in air not for radon in water. A 'bubbler' had be developed that performs the degassing process. The techniques will be presented. Through stable results from our instrument developments, we observed different radon

  2. Contribution of (222)Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China.

    Science.gov (United States)

    Song, Gang; Wang, Xinming; Chen, Diyun; Chen, Yongheng

    2011-04-01

    This study investigates the contribution of radon ((222)Rn)-bearing water to indoor (222)Rn in thermal baths. The (222)Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM(10) and PM(2.5)) and carbon dioxide (CO(2)) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m(-3) of (222)Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which (222)Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average (222)Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor (222)Rn levels were influenced by the (222)Rn concentrations in the hot spring water and the bathing times. The average (222)Rn transfer coefficients from water to air were 6.2 × 10(-4)-4.1 × 10(-3). The 24-h average levels of CO(2) and PM(10) in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM(2.5). Radon and PM(10) levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Measurements of 222 Rn in the indoor of dwellings in the Argentinean Republic

    International Nuclear Information System (INIS)

    Canoba, A.; Lopez, F.

    2006-01-01

    The 222 Rn is responsible for approximately half of the dose in the population resultant of the exposure to natural radiation. Most of this dose comes from the inhalation of the offspring of the 222 Rn, and these doses they are specially important in set closed. The concentration of gas radon has been measured in housings of different cities of the Argentinean Republic. The elected cities are representative of the different geologic areas of our territory. For this its were used as detecting measurement method of nuclear tracks, electret detectors and detectors based on the adsorption in activated coal. Its were analyzed a total of 2689 housings from 1983 to the date. The average value of the radon concentration obtained starting from the 2689 monitored housings was of 41.6 Bq.m -3 . The effective annual dose calculated starting from this radon concentration, using a dosimetric factor of 25 μSv.a -1 (Bq.m -3 ), which assumes an equilibrium factor of 0.4, was of 1.04 mSv. Also, with the objective of determining the dose in form more exact, during the year 2000 it put on to point a passive technique for the simultaneous measurement such the radon concentration like of the equilibrium factor. This technique uses in oneself device two detectors of nuclear traces. The average value obtained starting from 204 monitored housings by this method of simultaneous measurement turns out to be 47.1 Bq.m -3 and 0.36 the equilibrium factor, being obtained a value of effective annual dose of 1.38 mSv. It fits to highlight that are very few the values above 200 Bq.m -3 and in any case the 300 Bq.m -3 is overcome. Analyzing the average equilibrium factor measured of 0.36, it was concluded that having assumed an equilibrium factor of 0.4 was adequate, for what for great measurement campaigns it can continue using the simple method that determines only the radon concentration. Comparing the obtained results by both methods, although the first counts with a statistic more important

  4. Modelling the distribution of 222Rn concentration in a multi level, general purpose building

    International Nuclear Information System (INIS)

    Toro, Laszlo; Noditi, Mihaela; Gheorghe, Raluca; Gheorghe, Dan

    2008-01-01

    The importance of 222 Rn (radon) in the indoor air related to the exposure form natural sources is relatively well documented. About 30% of the individual effective dose from natural sources is coming from the inhalation of 222 Rn and his short lived daughters. In unfavorable conditions given by the soil porosity and the existence of upward air movement in the soil there is a possibility to have unusually high radon concentration in houses even on soil with 'normal' 226 Ra content. Some construction solutions (high indoor spaces) should generate a significant indoor-outdoor negative pressure differences and consequently upward air currents (stack effect) which will facilitate the entrance of radon in the building. This effect will multiply the possibility of migration of radon in the building. The difficulty of the prediction of radon migration in the soil-building system increase the importance of the mathematical modelling of the behavior of radon-soil emission, infiltration and migration in the building - in areas with high radon potential. For one level simple buildings there are several models in the literature but the information regarding the multilevel building models are relatively scarce. Two different approaches used to describe the behavior of the radon gas in large (mainly high) buildings have been analyzed: Direct approach: computational fluid dynamics, solving the transport equations for the whole building (the domain of the solution of the transport and flow equations is delimited by the building envelope - the external walls); the openings (internal and external) and ventilation are defined by the boundary conditions. This approach is quite complex, the equations are solved (numerically) for highly inhomogeneous medium but is based on the fundamental processes governing the transport. In the same time it gives the possibility to obtain a concentration pattern in every part of the building. Multi-zone approach treating the building as interconnected

  5. Calibration of a degassing-emanation line for 222Rn determination in seawater samples; Calibracao de uma linha de emanacao para determinacao de {sup 222}Rn em amostras de agua do mar

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Luciana Aparecida

    2002-07-01

    The purpose of this study is to calibrate a degassing-emanation line and to determine {sup 222}Rn and {sup 226}Ra activity concentrations in seawater samples. This methodology, also called Lucas method, consists in the extraction of radon (originally dissolved in seawater), collection of the gas in a liquid nitrogen cold trap and transfer from the trap to an alpha scintillation cell. Total extraction efficiencies of the 4 degassing-emanation systems were determined by measuring {sup 226}Ra reference solutions. The efficiencies obtained for these 4 systems varied from 21 % to 62%. This work also presents preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil: Flamengo Bay, Fortaleza Bay, Mar Virado Bay and Ubatuba Bay. Concentration of Rn in excess varied from 0,011 to 0,317 Bq/L for Flamengo Bay, from 0,009 to 0,130 Bq/L for Fortaleza Bay, from 0,018 to 0,050 Bq/L for Mar Virado Bay and from 0,004 to 0,120 Bq/L for Ubatuba Bay. The results obtained for the concentration of {sup 222}Rn in excess in a transect at Flamengo Bay varied from 0,002 to 0,036 Bq/L. Higher concentrations of {sup 222}Rn in excess were obtained in Flamengo Bay, Fortaleza Bay and Ubatuba bay. It was also observed that the concentration of {sup 222}Rn in excess increases with depth, as expected. (author)

  6. Measurement of 226Ra in water and 222Rn in water and air by liquid scintillation counting

    International Nuclear Information System (INIS)

    Schoenhofer, F.

    1992-01-01

    In the Austrian province of Lower Austria a comprehensive programme for measurement of 222 Rn and 226 Ra in drinking water was conducted. A simple liquid scintillation counting (LSC) method was used which gives a LLD of 30 mBq per litre for 226 Ra without any chemical separation. Results are presented and the health significance is discussed. For 222 Rn in air a commercially available simple charcoal system with LSC was used. The system was tested in a house with elevated radon concentration under normal living conditions. During relatively short 2-day periods a maximum deviation of ± 30% from the monthly mean value was found. The advantages of LSC are that the procedures are very simple and cheap. (author)

  7. Internal exposure to 222Rn progeny of the underground workers in Bulgarian uranian mines in 1958-1989

    International Nuclear Information System (INIS)

    Dimitrov, M.; Presiyanov, D.

    1998-01-01

    The results of more than 50000 measurements of 222 Rn and 22R n progeny measurements made in 1958-1989 in 9 large Bulgarian uranium mines (namely: '9 septemvri', 'Seslavci', 'Eleshnitsa 1, 2, 3', 'Smolyan', 'Byalata voda', 'Balkan' and 'Smolyanovtsi') have been summarized. The average WLM-exposures have been determined for each of the mines. The results make possible to estimate internal WLM exposure of any miner, provided that his underground working experience is known

  8. An interesting use of 222 Rn in the study of the flow velocities in the coastal karstic aquifers

    International Nuclear Information System (INIS)

    Cesario, G.; Tinelli, R.

    2001-01-01

    Pollution phenomena which are more and more affecting groundwater, do require recovery actions which cannot fail to take into account the knowledge of filtration velocity, V f . Science literature, by now, includes a great deal of hydrogeological studies which stressed 222 Rn reliability as groundwater mobility indicator. In general, and not considering the nature of the aquifer, it was found that a higher mobility of waters corresponds to a higher radon content. Starting from such considerations and firmly considering experiences gathered so far within the coastal aquifer study, a swift method correlating groundwater filtration velocity to their radon content was implemented. This, later made it possible to obtain, by means of the 222 Rn isochores, isoradon map, valuable information on groundwater velocity even on far-reaching areas by only effecting few V f direct measurements. This method, then, was tested on the field in the Salento coastal area Torre S. Isidoro, where the aquifer presents hydraulic, chemical-physical parameters such eto be macroscopically considered as homogeneous. The validity of the method not only was it fully supported by this check, but also evidenced the reliability of information provided by the radon isochore maps with respect to the ones obtainable from the classical isothermal and isohaline map. Suggested method, then, offers a double advantage: to reduce to the minimum V f direct measurements, which are costly owing to the use of radioactive tracers, and to complete and/or confirm information collected from other maps. Finally, this study has also pointed out the presence of high 222 Rn in practically still groundwater, but subject to sea level continuous oscillations. Of course this work also relates to mechanisms this phenomenon is based on, as well as 222 Rn ratio [it

  9. Seasonal variation of 226Ra and 222Rn in mineral spring waters of Aguas da Prata-Brazil

    International Nuclear Information System (INIS)

    Oliveira, J. de; Mazzilli, B.; Oliveira S, M.H de; Bernadete, S.

    1996-01-01

    Concentration levels of 226 Ra and 222 Rn have been analysed in most of the mineral spring waters available in the Aguas da Prata region, which is located in the Pocos de Caldas plateau, one of the biggest weathered alkaline intrusions of the world. In this plateau can be found many health resorts[based on springs of thermal and mineral waters. The Aguas da Prata spring waters show a large variety of composition. It has been observed bicarbonates, carbonates and sulphates salts in these mineral waters. The 226 Ra was determined by gross alpha counting of a Ba(Ra)SO 4 precipitate. The measurement was carried out in a low background gas flow proportional counter. The 222 Rn concentrations were determined by liquid scintillation method. Water samples were randomly collected at 9 spring sites over a period of one year, in order to evaluate the seasonal variation of these radionuclides. Lower concentrations were found mostly in the rainy season (summer), which presents 80% of the annual rainfall of the region (1500 mm/year). Higher concentrations up to 2223 mBq/L for 226 Ra and 131 Bq/L for 222 Rn have been observed in waters with low level of soluble salts. Waters which present high levels of carbonate and sulphate salts showed maximum values of 316 mBq/L for 226 Ra and 30 Bq/L for 222 Rn. This behaviour is mainly due to the physicochemical properties of these radionuclides in water as well as to the lithologic structure of the aquifers. (authors). 6 refs., 2 figs., 1 tab

  10. Measurement of radon (222Rn) in thermal water of Cerro Pacho, Coatepeque Caldera, El Salvador

    International Nuclear Information System (INIS)

    Rodriguez, Ramiro; Olmos, Rodolfo; Payes, Julio

    2014-01-01

    Radon ( 222 Rn) concentrations and radio ( 226 Ra) evaluation dissolved in thermal spring water are presented to contribute to volcanic monitoring, adapting and validating analytical methodology. Sampling was discreet and monthly type, from June 2011 to March 2013. Radon levels was vary from 0,48 ± 0,1 to 1,54 ± 0,13 Bq/L (average 1,24 Bq/L). Radio concentrations were evaluated from January to December 2012. The values found do not show radio detection confidence level of 95% with respect to the detection limit (4,2 mBq/L). A decrease in radon was observed possibly related to subduction anomalies with epicenter at 143 km from Cerro Pacho, in November 2012, volcanic seismicity was also recorded 40 days before with increments of microearthquakes and volcano-tectonic activity. The first measurements of radon in thermal water have been generated, establishing the baseline to evaluate the behavior of these radionuclides with seismic activity. (author) [es

  11. The measurement of 222Rn in drinking water by low-level liquid scintillation counting

    International Nuclear Information System (INIS)

    Barnett, J.M.; McKlveen, J.W.

    1992-01-01

    Radon-222 (Rn) has universally been found in well water. Non-stagnant ground water is collected at the well head while the well is pumping. The water is adjusted to a slow, non-aerated, steady flow through a clear tube, and a 500 ml glass bottle is filled. The sample is tightly capped after a high meniscus has developed. In the laboratory, standard 22 ml glass vials are filled with 10 ml of a toluene based mineral oil LS cocktail. Then, two 5 ml sample aliquots are pipetted into the vial. Vials are capped tightly, shaken vigorously, and placed in the liquid scintillation (LS) counter. Secular equilibrium is established in approximately 4 hours, after which samples are counted for 100 minutes each. The counting efficiency for Rn and progeny ranges between 315 to 345 percent depending on the chosen spectral window. The average background is about 6 cpm. A total of 28 wells were tested for Rn in the Carefree-Cave Creek, Arizone, USA area. The area's geometric average Rn concentration was found to be 46.5 Bq*1 -1 . The associated estimated lung dose is 0.51 mSv*y -1 . (author) 8 refs.; 1 fig.; 1 tab

  12. Seasonal variation of 222Rn in seawater samples from Ubatuba embayments, SP, Brazil, for the assessment of submarine groundwater discharge

    International Nuclear Information System (INIS)

    Lopes, Patricia da Costa

    2005-01-01

    We describe here an application of excess 222 Rn to estimate SGD in a series of small embayments of Ubatuba, Sao Paulo State, Brazil, covering latitudes between 23 deg 26'S and 23 deg 46'S and longitudes between 45 deg 02'W e 45 deg 11'W. Excess 222 Rn inventories obtained in 24 vertical profiles established from March/03 to July/05 varied from 345 ±±24 to 18,700 ± 4,900 dpm/m 2 . The highest inventories of excess 222 Rn were observed both in Flamengo and Fortaleza embayments, during summer campaigns (rainy season). The estimated total fluxes required to support inventories measured varied from 62 ± 4 to 3,385 +- 880 dpm/m 2 d. Considering these results, the SGD advective rates necessary to balance the fluxes calculated in Ubatuba embayments ranged from 0.1 x 10 -1 to 1.9 cm/d. Taking into account all SGD fluxes obtained, the percentual variability was 89% (seasonal variation in 3 years period, n = 24 measurements). Although, if we consider each year of study separately, the respective percentual variabilities estimated are 72% in 2003 (n = 10 measurements), 127% in 2004 (n = 6 measurements) and 97% in 2005 (n = 8 measurements). (author)

  13. MODEL RADIOACTIVE RADON DECAY

    Directory of Open Access Journals (Sweden)

    R.I. Parovik

    2012-06-01

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

  14. Joint determination of the concentrations of the 222Rn and 220Rn decay products in air

    International Nuclear Information System (INIS)

    Terent'ev, M.V.

    1987-01-01

    The authors describe a modification of the Kuznets and Markov methods normally employed for the determination of radon 220 and 222 daughter alpha product concentration in air in which an air sample is taken for 10 minutes on a filter at a flow rate of 10-40 liters per minute. After the conclusion of sampling the filter activity is measured for another 10 minutes. In order to then determine the latent energy of the radon 222 daughter products and to bring into account the radon 220 daughter products in the total activity measurements of the filter are taken for a second time for 30 minutes five hours after initial sampling. The level of latent energy of the combined daughter products are calculated by an equation which incorporates alpha particle detection efficiency, aerosol retention efficiency in the filter, and the Kuznets coefficients, and analyzes the separate and combined contributions of both daughter products from both sampling periods. A statistical analysis employing the Markov method is also depicted in modified form and is recommended when a more rapid analysis of air radioactivity is mandated

  15. Quantitative measurement of 222Rn in water by the activated charcoal passive collector method: 1. The effect of water in a collector

    International Nuclear Information System (INIS)

    Yoneda, Minoru; Inoue, Yoriteru; Yoshimoto, Keizo

    1994-01-01

    The activated charcoal passive collector method can be applied to measure the concentration of 222 Rn in river water. The 222 Rn collector is composed of dry activated charcoal sealed in a polyethylene bag. However, we found it very difficult to keep activated charcoal in a collector dry during the period the collector was left in a river. The degree of dampness and the time lapsed when activated charcoal became wet were thought to affect the quantity of 222 Rn collected. First, we studied the effect of some parameters in the activated charcoal passive collector method qualitatively in three experiments. We found that the quantity of 222 Rn collected in a collector was not so sensitive to the quantity of activated charcoal in the collector or the thickness of polyethylene film under the condition of wet activated charcoal, and that wet activated charcoal accumulated less 222 Rn than dry activated charcoal. We present some equations which could explain how much 222 Rn was collected in a collector when activated charcoal was submerged directly in water and when activated charcoal was packed in a polyethylene bag but completely wet. These equations were proved effective by being compared with the results of the other experiments. Finally, we recommended some conditions which proved useful when measuring at an actual river

  16. The role of mesoscale meteorology in modulating the (222)Rn concentrations in Huelva (Spain)--impact of phosphogypsum piles.

    Science.gov (United States)

    Hernández-Ceballos, M A; Vargas, A; Arnold, D; Bolívar, J P

    2015-07-01

    The combined analysis of (222)Rn activity concentrations and mesoscale meteorological conditions at Huelva city (Spain) was addressed in this study to understand the potential impact of phosphogypsum piles on the (222)Rn activity concentrations registered at this area. Hourly mean data from April 2012 to February 2013 registered at two sampling sites (Huelva city and in the background station of El Arenosillo, located 27 km to the south-east) have been used in the study. The results of the present study showed a large difference in mean radon concentrations between the two stations during the sampling period, 6.3 ± 0.4 Bq m(-3) at Huelva and 3.0 ± 0.2 Bq m(-3) at El Arenosillo. The analysis has demonstrated that hourly (222)Rn concentrations at Huelva city above 22 Bq m(-3), with nocturnal peaks up to 50 Bq/m(3), mainly coincided with the occurrence of a pure sea-land breeze cycle. Mesoscale circulations in this region are mainly characterized by two patterns of sea-land breeze, pure and non-pure, with the phosphosypsum piles directly upstream (south) of the city during the afternoon on pure sea-breeze days. The difference between mean (222)Rn activity concentrations at Huelva city were 9.9 ± 1.5 Bq m(-3) for the pure pattern and 3.3 ± 0.5 Bq m(-3) for the non-pure pattern, while in the background station concentrations were 3.9 ± 0.4 Bq m(-3) and 2.8 ± 0.4 Bq m(-3) respectively. Considering these large differences, a detailed analysis of composites and case studies of representative sea-land breeze cycles of both types and their impact on (222)Rn activity concentration was performed. The results suggested that the presence of the phosphogypsum piles was necessary in order to justify the high (222)Rn activity concentrations observed at Huelva compared with the background station in the afternoons on pure sea breeze days (1.5-2.0 Bq m(-3)). On the other hand, large night time differences between the two sites on these days were

  17. Contribution of {sup 222}Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China

    Energy Technology Data Exchange (ETDEWEB)

    Song Gang, E-mail: songg2005@126.co [School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006 (China); Wang Xinming [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Diyun; Chen Yongheng [School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006 (China)

    2011-04-15

    This study investigates the contribution of radon ({sup 222}Rn)-bearing water to indoor {sup 222}Rn in thermal baths. The {sup 222}Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM{sub 10} and PM{sub 2.5}) and carbon dioxide (CO{sub 2}) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m{sup -3} of {sup 222}Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which {sup 222}Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average {sup 222}Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor {sup 222}Rn levels were influenced by the {sup 222}Rn concentrations in the hot spring water and the bathing times. The average {sup 222}Rn transfer coefficients from water to air were 6.2 x 10{sup -4}-4.1 x 10{sup -3}. The 24-h average levels of CO{sub 2} and PM{sub 10} in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM{sub 2.5}. Radon and PM{sub 10} levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. - Highlights: {yields} {sup 222}Rn-bearing water is the main contributor to indoor radon in hot spring hotel. {yields} The PM{sub 2.5} and CO{sub 2} are also the main indoor pollutants in the hotel rooms. {yields} Higher radon and PM levels might have significant negative health effects to human. {yields} The radon transfer coefficients are consistent with the published data.

  18. Contribution of 222Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China

    International Nuclear Information System (INIS)

    Song Gang; Wang Xinming; Chen Diyun; Chen Yongheng

    2011-01-01

    This study investigates the contribution of radon ( 222 Rn)-bearing water to indoor 222 Rn in thermal baths. The 222 Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM 10 and PM 2.5 ) and carbon dioxide (CO 2 ) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m -3 of 222 Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which 222 Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average 222 Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor 222 Rn levels were influenced by the 222 Rn concentrations in the hot spring water and the bathing times. The average 222 Rn transfer coefficients from water to air were 6.2 x 10 -4 -4.1 x 10 -3 . The 24-h average levels of CO 2 and PM 10 in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM 2.5 . Radon and PM 10 levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. - Highlights: → 222 Rn-bearing water is the main contributor to indoor radon in hot spring hotel. → The PM 2.5 and CO 2 are also the main indoor pollutants in the hotel rooms. → Higher radon and PM levels might have significant negative health effects to human. → The radon transfer coefficients are consistent with the published data.

  19. 222 Rn exposure assessment in the caves of Parque Estadual Turistico do Alto Ribeira (PETAR)

    International Nuclear Information System (INIS)

    Alberigi, Simone

    2006-01-01

    In the present work, radon concentrations in six caves of PETAR - Parque Estadual Turistico do Alto Ribeira (High Ribeira River Touristic State Park) were carried out with Makrofol E solid state nuclear track detectors (SSNTD) and used to assess the annual effective dose received by regional tour guides. The park has four visitation centers: Santana, Ouro Grosso, Caboclos e Casa de Pedra and receives nearly 40,000 people annually. The caves evaluated were Couto, Agua Suja, Laje Branca, Morro Preto and Santana, from Santana center and Alambari de Baixo from Ouro Grosso center, for being the most frequently visited caves. The exposure period of the SSNTD was, at least, three months, over a period of 26 months, from October 2003 to November 2005.The 222 Rn concentrations lay in a range from 153 Bq.m -3 to 6607 Bq.m -3 and we observed that, in general, for chilly weather, the radon levels decrease. The annual effective dose, considering the most realistic scenario, with geometric mean concentrations, an equilibrium factor of 0.5 and annual exposure time for each cave, varied from 0.2 mSv.a -1 for the Couto cave, strongly ventilated, to 4.0 mSv.a -1 for the Santana cave, the most frequently visited and no external communication. For the worst scenario, with arithmetic mean concentrations, equilibrium factor 1 and annual exposure time for all caves, the annual effective dose was 16.1 mSv.a -1 . All assessed effective doses received by the tour guides are bellow 20 mSv.a -1 suggested as an annual effective dose limit for occupational exposure by the International Commission of Radiological Protection (ICRP 60, 1990). (author)

  20. 222Rn, 226Ra, and U in drinking water in Hungary

    International Nuclear Information System (INIS)

    Szerbin, P.; Koeteles, G.

    2002-01-01

    Among radionuclides ingested by drinking water the most important ones are radon, radium and uranium, causing radiation exposure of the lungs, bones, and gastro-intestinal organs, mainly kidneys. For this reason, as a part of the National Environmental Health Program to determine the main risk factors of the Hungarian population from environmental substances, 222 Rn, 226 Ra, and U concentrations were measured in domestic water supplies. Water samples were taken from all of the 19 Hungarian counties. Three cities were chosen from each county by the criteria of number of the population. Samples were taken from the communal drinking water supplies. Radon was determined by short lived daughter products using scintillation technique after water degassing into Lucas cells. Radium and uranium were determined after chemical separation, by Lucas scintillation method and by liquid scintillation technique. The obtained results were compared to the available literature data. Radioactivity levels were assessed for conformity with the Hungarian standards, WHO guidelines, and used for dose calculations. It was concluded that the radioactivity of the drinking water in Hungary is in the order of magnitude of the worldwide average. The measured radioactivity levels never exceeded the limits of the valid Hungarian standards for annual intake limits and were adequate to WHO guidelines. It was found that public doses from radon, radium, and uranium ingestion by drinking water were 12.7, 8.8, and 7.3 μSv y -1 , respectively. Summarizing the results of the survey it was concluded that comparing these doses to the public dose from other natural sources of radiation are negligibly small. (author)

  1. The activity concentrations of 222Rn and corresponding health risk in groundwater samples from basement and sandstone aquifer; the correlation to physicochemical parameters

    International Nuclear Information System (INIS)

    Abdurabu, Wedad Ali; Ramli, Ahmad Termizi; Saleh, Muneer Aziz; Heryansyah, Arien

    2016-01-01

    This study aims to evaluate the activity concentrations of 222 Rn and to assess the corresponding health risk in groundwater samples obtained in Juban District, Ad Dali’ Governorate, Yemen. The measurements were performed by RAD 7 radon detector manufactured by DURRIDGE COMPANY Inc. The activity concentrations of 222 Rn ranged from 1.0±0.2 Bq l −1 to 896.0±0.8 Bq l −1 . 57% of the groundwater samples were above the US Environmental Protection Agency (USEPA) recommended value for Rn in water. Induced coupled plasma mass spectrometry (ICP-MS) was used to determine the concentrations of uranium in groundwater samples. The measured concentration of U ranged from 0.33±0.01 μg l −1 to 24.6±0.6 μg l −1 . The results were comparable to internationally recommended values. The highest concentration of U and 222 Rn were found to be in the basement aquifer, while the lowest concentrations of both radionuclides were in the sandstone aquifer. High concentrations of Rn are found along fault zones. The relationship between the activity concentration of 222 Rn, concentration of U and physicochemical parameters were investigated. The results showed a very strong relationship between activity concentrations of 222 Rn with concentrations of U and the salinity of water. - Highlights: • The highest concentration of U and 222 Rn was found to be in the basement aquifer. • A 57% of the groundwater samples were above the USEPA recommended value. • Mean annual effective dose for ingestion was 24 times the world average. • Mean annual effective dose for inhalation was 23 times the world. • Strong relationship between 222 Rn with concentration of U in the basement aquifer.

  2. Evolution of {sup 222} Rn and chemical species related with eruptive processes of the Popocatepetl volcano; Evolucion de {sup 222} Rn y especies quimicas relacionadas con procesos eruptivos del volcan Popocatepetl

    Energy Technology Data Exchange (ETDEWEB)

    Aranda, P.; Ceballos, S.; Cruz, D.; Hernandez, A.; Lopez, R.; Pena, P.; Salazar, S.; Segovia, N.; Tamez, E. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The {sup 222} Rn monitoring in the Popocatepetl volcano was initiated on 1993. At December 21, 1994 it is initiated an eruptive stage in the volcano with gas emission, ashes and the lava dome formation on the crater at middle 1996. During all this time it has been determined radon concentrations on soils with active and passive detectors. In this work the changes in radon contents are reported also the physicochemical parameters in spring water related with the volcanic building associated to the recent activity of the volcano. (Author)

  3. Determine concentration radon 222Rn in the air inside and outside the buildings at the summer province of Baghdad

    International Nuclear Information System (INIS)

    Al-Ataby, N.R.; Aisa, B.H.; Jebir, H.M.; Hatem, J.N.

    2010-01-01

    In this study, Was use of solid-state nuclear track detectors in the measurement of concentrations of radon 222 Rn inside and outside of the buildings in the summer and winter of the Baghdad province and because of the high features of the technical sensitivity and efficiency to record track of charged particles (such as protons and alpha particles and fission fragments) . Is the radon of Environmental Pollutions that is caused health problems , that was seemed the concern at the problem of pollution, radon gas 222 Rn and thoron gas 220 Rn and the considerable risk resulting from exposure to these isotopes by alpha particles emitted which have proved the relationship between exposure to emitted alpha particles with the incidence of disease of lung cancer. In this study, measured the concentration of radon 222 Rn inside and outside buildings in the summer and winter in several areas from the Baghdad province and as showed in the attached tables. Been studied the environmental radioactivity and measurement of the concentration of radon gas in the air in different parts of the city of Baghdad. the highest concentration was Found in the second Orf ali (A) (of the Sadr City) for the summer and was (37.973 Bq/m3) outside the building and ((53.400 Bq/m3 inside the building, either for the winter season was (55.773 Bq/m3) outside the building and (Bq/m3 58.148) inside the building for the same region and This is the concentration within the limits allowed

  4. Estimating the standard deviation for 222Rn scintillation counting - a note concerning the paper by Sarmiento et al

    International Nuclear Information System (INIS)

    Key, R.M.

    1977-01-01

    In a recent report Sarmiento et al.(1976) presented a method for estimating the statistical error associated with 222 Rn scintillation counting. Because of certain approximations, the method is less accurate than that of an earlier work by Lucas and Woodward (1964). The Sarmiento method and the Lucas method are compared, and the magnitude of errors incurred using the approximations are determined. For counting times greater than 300 minutes, the disadvantage of the slight inaccuracies of the Sarmiento method are outweighed by the advantage of easier calculation. (Auth.)

  5. Risk of 222 Rn ingestion by water consumption in the phosphate rich of the Northeast of Brazil

    International Nuclear Information System (INIS)

    Andrade Lima, Ricardo de

    1997-01-01

    Geological survey performed in the coastal region of the northeast of Brazil revealed the presence of uranium phosphate deposits in a land strip covering the Pernambuco-Bahia sedimentary basin. The water consumed by the local population crosses the phosphate area and presents higher tna normal concentration of uranium and its progeny. This work is aimed to determine the cancer risk, based on the rate ingestion of the 222 'Rn due to water consumption. The results of the analysis showed increments of 1.25% for cancer occurrences due to Rn-222 ingestion for the local population. (author). 11 refs., 1 fig., 1 tab

  6. 222Rn and short live progeny in atmospheric environment. Origin and measurement techniques

    International Nuclear Information System (INIS)

    Charuau, J.; Labed, V.; Robe, M.C.; Thevenin, J.C.; Fazileabasse, J.; Klein, D.; Heleschewitz, H.; Tymen, G.; Aubert, C.; Gibaud, C.

    1996-01-01

    Radon is the main source of man's exposure to natural ionizing radiation. This document summarizes the general knowledge of the origin of radon 222 and its development in various air environments. It presents several methods for measuring radon activity concentration and the potential alpha energy from its short life daughters. It has been prepared by the commission M60-3, of the Office for the standardization of nuclear equipments (BNEN in French) under the French association for standardization (AFNOR in French). (author)

  7. Long-lived 222Rn progeny concentrations in ground level air of Milan

    International Nuclear Information System (INIS)

    Marcazzan, G.M.; Valli, G.; Vecchi, R.; Bocelli, R.

    2002-01-01

    Short-lived (2 18P o, 2 14P b, 2 14B i, 2 14P o) as well as long-lived (2 10P b, 2 10B i, 2 10P o) Radon's decay products in atmosphere are due to the 2 22R n exhalation from the continental Earth's crust, where it is generated in the 2 38U decay series. The measurement of the radionuclides concentration in the atmosphere - in addition to yielding valuable data for radioprotection purposes and for assessing the environmental impact of natural radioactivity - can provide information on atmospheric thermodynamic conditions as well as on atmospheric processes that involve aerosols such as transport, dispersion, removal rates and residence time. In particular, the concentration ratio of 2 10P b with other Radon's daughters can be used to obtain information on mean residence time of aerosols (Poet et al., 1972; Rangarajan, 1992; Gaggeler et al., 1995). Continuous measurements of hourly concentration of Radon and its short-lived progeny are routinely carried out in Milan by our group, and the temporal behaviour comes out a suitable tracer of atmospheric stability conditions and a local index of the evolution of the mixing layer height (Marcazzan et al., 1993; Marcazzan et al., 1997). The aim of this work was to measure the concentration and temporal behaviour of 2 10P b on a weekly and a monthly scale at ground level in the urban area of Milan and to get reliable measurements on the annual average concentration for the implementation of the existing data base (Preiss et al., 1996)

  8. The GENIUS-test-facility--first results on background from {sup 222}Rn daughters

    Energy Technology Data Exchange (ETDEWEB)

    Klapdor-Kleingrothaus, H.V. E-mail: H.Klapdor@mpi-hd.mpg.dehttp://www.mpi-hd.mpg.de.non_acc; Tomei, C.; Krivosheina, I.V.; Chkvorets, O

    2004-09-11

    GENIUS-TF (Nucl. Instr. and Meth. A 511 (2003) 341; Nucl. Instr. and Meth. A 481 (2002) 149.) is a test-facility for the GENIUS project (GENIUS-Proposal, 20 November 1997; Z. Phys. A 359 (1997) 351; CERN Courier, November 1997, 16; J. Phys. G 24 (1998) 483; Z. Phys. A 359 (1997) 361; in: H.V. Klapdor-Kleingrothaus, H. Pas. (Eds.), First International Conference on Particle Physics Beyond the Standard Model, Castle Ringberg, Germany, 8-14 June 1997, IOP Bristol (1998) 485 and in Int. J. Mod. Phys. A 13 (1998) 3953; in: H.V. Klapdor-Kleingrothaus, I.V. Krivosheina (Eds.), Proceedings of the Second International Conference on Particle Physics Beyond the Standard Model BEYOND' 99, Castle Ringberg, Germany 6-12 June 1999, IOP Bristol (2000) 915), a proposed large scale underground observatory for rare events which is based on operation of naked germanium detectors in liquid nitrogen for an extreme background reduction. Operation of naked Ge crystals in liquid nitrogen has been applied routinely already for more than 20 years by the CANBERRA Company for technical functions tests (CANBERRA Company, private communication, 5 March 2004.), but it never had found entrance into basic research. Only in 1997 first tests of application of this method for nuclear spectroscopy have been performed, successfully, in Heidelberg (Klapdor-Kleingrothaus et al., 1997, 1998; J. Hellmig and H.V. Klapdor-Kleingrothaus, 1997). On May 5, 2003 the first four naked high-purity germanium detectors (total mass 10.52 kg) were installed in liquid nitrogen in the GENIUS Test Facility at the Gran Sasso underground laboratory. Since then the experiment has been running continuously, testing for the first time the novel technique in an underground laboratory and for a long-lasting period. In this work, we present the first analysis of the GENIUS-TF background after the completion of the external shielding, which took place in December 2003. We focus especially on the background coming from {sup 222

  9. The GENIUS-test-facility--first results on background from 222Rn daughters

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.; Tomei, C.; Krivosheina, I.V.; Chkvorets, O.

    2004-01-01

    GENIUS-TF (Nucl. Instr. and Meth. A 511 (2003) 341; Nucl. Instr. and Meth. A 481 (2002) 149.) is a test-facility for the GENIUS project (GENIUS-Proposal, 20 November 1997; Z. Phys. A 359 (1997) 351; CERN Courier, November 1997, 16; J. Phys. G 24 (1998) 483; Z. Phys. A 359 (1997) 361; in: H.V. Klapdor-Kleingrothaus, H. Pas. (Eds.), First International Conference on Particle Physics Beyond the Standard Model, Castle Ringberg, Germany, 8-14 June 1997, IOP Bristol (1998) 485 and in Int. J. Mod. Phys. A 13 (1998) 3953; in: H.V. Klapdor-Kleingrothaus, I.V. Krivosheina (Eds.), Proceedings of the Second International Conference on Particle Physics Beyond the Standard Model BEYOND' 99, Castle Ringberg, Germany 6-12 June 1999, IOP Bristol (2000) 915), a proposed large scale underground observatory for rare events which is based on operation of naked germanium detectors in liquid nitrogen for an extreme background reduction. Operation of naked Ge crystals in liquid nitrogen has been applied routinely already for more than 20 years by the CANBERRA Company for technical functions tests (CANBERRA Company, private communication, 5 March 2004.), but it never had found entrance into basic research. Only in 1997 first tests of application of this method for nuclear spectroscopy have been performed, successfully, in Heidelberg (Klapdor-Kleingrothaus et al., 1997, 1998; J. Hellmig and H.V. Klapdor-Kleingrothaus, 1997). On May 5, 2003 the first four naked high-purity germanium detectors (total mass 10.52 kg) were installed in liquid nitrogen in the GENIUS Test Facility at the Gran Sasso underground laboratory. Since then the experiment has been running continuously, testing for the first time the novel technique in an underground laboratory and for a long-lasting period. In this work, we present the first analysis of the GENIUS-TF background after the completion of the external shielding, which took place in December 2003. We focus especially on the background coming from 222 Rn

  10. Direct determination of 222Rn gas using the electret to remove daughters at formation. Annual progress report, June 1, 1981-May 31, 1982

    International Nuclear Information System (INIS)

    Harley, N.H.

    1982-01-01

    This report covers progress made from 1 June 1981 to 31 May 1982 in developing a continuous monitor which measures only 222 Rn without interference from the daughters. Five 222 Rn counters have been built which determine 222 Rn alone by alpha scintillation counting in the presence of an electret to remove the short-lived daughter products from the counting chamber. The chamber design is based on the work of Chittaporn et al., (1981) at New York University's Department of Environmental Medicine. The detection chamber is a 1.8 liter (12.7 cm diameter by 14 cm high) cylinder lined with zinc sulfide alpha phosphor. The detector sits directly on a 12.7 cm diameter phototube. The 5 units have calibration factors which range from 155 to 186 counts/hour per pCi 222 Rn/liter and an average background count of 6 counts/hour. The lower limit of detection for a one hour count is thus 0.03 pCi 222 Rn/l, well below environmental levels

  11. Assessment of {sup 222}Rn occupational exposure at IPEN nuclear materials storage site, SP, Brazil; Avaliacao da exposicao ocupacional ao {sup 222}Rn no galpao da Salvaguardas do IPEN, SP

    Energy Technology Data Exchange (ETDEWEB)

    Caccuri, Lilian Saueia

    2007-07-01

    In this study it was assessed the occupational exposure to {sup 222}Rn at IPEN, SP, Brazil, nuclear materials storage site through the committed effective dose received by workers exposed to this radionuclide. The radiation dose was calculated through the radon concentrations at nuclear materials storage site. Radon concentrations were determined by passive detection method with solid state nuclear detectors (SSNTD). The SSNTD used in this study was the polycarbonate Makrofol E; each detector is a small square plastic of 1 cm{sup 2}, placed into a diffusion chamber type KFK. It was monitored 14 points at nuclear materials storage site and one external point, over a period of 21 months, changing the detectors every three months, from December 2004 to September 2006. The {sup 222}Rn concentrations varied from 196 {+-} 9 and 2048 {+-} 81 Bq{center_dot}m{sup -3}. The committed effective dose due to radon inhalation at IPEN nuclear materials storage site was obtained from radon activity incorporated and dose conversion factor, according to International Commission on Radiological Protection procedures. The effective committed dose received by workers is below 20 mSv{center_dot}y{sup -1}. This value is suggested as an annual effective dose limit for occupational exposure by ICRP 60. (author)

  12. Monte Carlo simulation of air sampling methods for the measurement of radon decay products.

    Science.gov (United States)

    Sima, Octavian; Luca, Aurelian; Sahagia, Maria

    2017-08-01

    A stochastic model of the processes involved in the measurement of the activity of the 222 Rn decay products was developed. The distributions of the relevant factors, including air sampling and radionuclide collection, are propagated using Monte Carlo simulation to the final distribution of the measurement results. The uncertainties of the 222 Rn decay products concentrations in the air are realistically evaluated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. The Noble Gas Radon ({sup 222}Rn) as a Hydrogeologic Tracer of Groundwater Inputs to Rivers and Hyporheic Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Stellato, L. [Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE), Seconda Universita degli Studi di Napoli, Caserta (Italy); Newman, B. D. [Isotope Hydrology Section, International Atomic Energy Agency, Vienna (Austria)

    2013-05-15

    The study of nutrient dynamics in lotic ecosystems often requires background knowledge of the hydrologic processes occurring both at large scales and at small scales in order to adopt effective management practices. In particular, surface water/subsurface water interactions can significantly alter nutrient loading in streams and rivers. Two case studies are reported as examples of large scale and small scale investigations carried out by means of an integrated approach where {sup 222}Rn was used: (i) to determine fractions of groundwater inflow to total discharge of a river and to identify sections with flow-through conditions, applying a degassing corrected, two component mixing model; (ii) to estimate water residence time within the hyporheic zone by applying a solute mass balance equation based on radon disequilibrium between pore water and stream water. The two case studies demonstrate that {sup 222}Rn is an effective tool in the study of interactions between surface and subsurface waters when groundwater inputs to rivers have to be quantified and in estimating the residence time of surface water in the hyporheic zone. However, an integrated approach including other hydrological and biogeochemical measurements is always recommended when complex processes have to be elucidated. (author)

  14. Improvement of measuring methods and instrumentation concerning 222Rn determination in drinking waters – RAD7 and LSC technique comparison

    International Nuclear Information System (INIS)

    Stojković, Ivana; Tenjović, Branislava; Nikolov, Jovana; Vesković, Miroslav; Mrđa, Dušan; Todorović, Nataša

    2015-01-01

    A procedure for the determination of 222 Rn in environmental water samples using liquid scintillation counting (LSC) was applied and optimized. A minimum detectable activity of 0.029 Bq l −1 in a 20 ml glass vial (10 ml water sample mixed with 10 ml of liquid scintillation cocktail) has been achieved during 300 min of measurement time. The procedure was compared with RAD7 radon detector measurements. 226 Ra content in the water was determined by gamma-ray spectroscopy. Applications to drinking waters collected from public drinking fountains in the Vojvodina (Serbia) are presented with annual effective dose for ingestion and inhalation for adults calculated. - Highlights: • A procedure for the determination of 222 Rn in environmental water samples using liquid scintillation counting (LSC) was applied and optimized. • The procedure was compared with RAD7 radon detector measurements. • A minimum detectable activity of 0.029 Bq l −1 in 10 ml of sample has been achieved in glass vials during 300 min of measurement time. • 226 Ra content in the water was determined by gamma-ray spectroscopy. • Applications to drinking waters collected from public drinking fountains in the Vojvodina (Serbia) are presented with annual effective dose for ingestion and inhalation for adults calculated

  15. Current issues and ways to reduce the negative impact of environment increased concentrations of Radon ({sup 222}Rn); Probleme actuale si tehnologii de reducerea a impactului negative al concentratiilor avansate de radon ({sup 222}Rn) in mediul ambiant

    Energy Technology Data Exchange (ETDEWEB)

    Coretchi, Liubov; Bahnarel, Ion; Apostol, Ion; Virlan, Serghei [Centrul National de Sanatate Publica, Chisinau (Moldova, Republic of)

    2012-10-15

    (This study was conducted to review the latest research in radon problem carried out by scientists of Moldova, the 13 EU countries and the USA, and relevant international organizations. Particular attention was paid to contradictions between energy efficiency measures and these of mitigation of {sup 222}Rn negative impact on human health. The main proposals developed were focused on the need for a National Radon Strategy (NRS) and a National Action Plan (NAP) for NRS implementation. Both NRS and NAP has to be correlated with other national policies, such as Smoking Reducing or Energy Efficiency. Development of a Radon Database including a map of radon concentrations, as well as a set of requirements for new housing construction, would be among the main components of NAP. (authors)

  16. Estimated doses related to {sup 222}Rn concentration in bunker for radiotherapy and storage of radioisotopes; Dosis estimada por concentraciones de {sup 222}Rn en bunker de radioterapia y de almacenamiento de isotopos radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Mestre, Freddy; Carrizales-Silva, Lila, E-mail: freddymest@gmail.com, E-mail: lcarriza@ivic.gob.ve [Instituto Venezolano de lnvestigaciones Cientificas, Caracas (Venezuela, Bolivarian Republic of); Sajo-Bohus, Laszlo, E-mail: sajobohus@gmail.com [Universidad Simon Bolivar, Caracas (Venezuela, Bolivarian Republic of). Laboratorio de Fisica Nuclear; Diaz, Cruz, E-mail: cruzediaZ@gmail.com [Universidad Pedagogica Experimental Libertador, Barquisimeto (Venezuela, Bolivarian Republic of). Instituto Pedagogico

    2013-07-01

    It was done a survey in radiotherapy services underground hospitals and clinics of Venezuela and Paraguay in order to estimate the concentrations of radon and its possible consequences on worker occupational exposure. Passive dosimeters were used to assess nuclear traces (NTD type CR-39 Registered-Sign ). The concentration of {sup 222}Rn is determined based on the density of traces using the calibration coefficient of 1 tr/cm{sup 2} equivalent to 0,434 Bqm{sup -3} per month of exposure. Assuming the most likely environmental conditions and the dose conversion factor equal to 9.0 x 10{sup -6} mSv h {sup -1} by Bqm{sup -3}, it was determined the average values and estimated the possible risks to health that are on average 3.0 mSva{sup -1} and 150 micro risk cancer.

  17. Evaluation of {sup 222}Rn concentration of the internal and external environments of residences at Monte Alegre municipality, Para, Brazil; Avaliacao da concentracao do {sup 222}Rn nos ambientes internos e externos de residencias do municipio de Monte Alegre, PA

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Vicente de Paula

    1999-07-01

    The human being is constantly exposed to the natural radioactivity in the environment where he lives. This radioactivity comes mainly from materials present in the terrestrial crust that possess in their constitution chemical elements belonging to the radioactive families of uranium and thorium. The use of such materials for the construction of houses constitutes an important exposure form to the natural radiation, above all to the radioactive gas {sup 222}Rn, that it is exhaled from them. The Brazilian soil is composed, among other, of minerals that contain appreciable concentrations of these elements. The inhabitants of Monte Alegre town in Para, located at 2 deg 00' 24,9 'S ; 54 deg 04 ' 13,5 {sup W}, used in the construction of their houses stones obtained from an area 20 km distant of Monte Alegre, denominated Ingles de Souza, located at 01 deg 56' 4 0,1 S; 54 deg 12 149,7 W, where a small residential village, denominated National Agricultural Colony of Para (CANP), is located. The objective of this work was to evaluate the indoor concentration of {sup 222}Rn in the residences of Monte Alegre and CANP. Determinations of the {sup 238}U and {sup 226}Ra concentrations, measurements of the radon flux in samples of stones and soils of the two regions, as well as measurements to the gamma dose close of the soil and inside the residences, were also carried out. The average results of the radon concentration in the air of the investigated residences did not exceed the limits of 200 Bq. m{sup 3} (action level) and 600 Bq. m{sup 3} (intervention level) recommended by the International Commission on Radiological Protection (ICRP). The concentrations of natural radionuclides and the radon flux determined at the village showed values 17 times higher than those found at the urban area of Monte Alegre, while the average indoor gamma dose rate in the village residences was 0.86 mSv/a. (author)

  18. Educational experiment for university students using natural radioactivity. Development of an additional experiment to measure the increase in 214Pb and 214Bi produced from 222Rn

    International Nuclear Information System (INIS)

    Nakamura, Mariko; Esaka, Takao; Kamata, Masahiro

    2005-01-01

    Although several works have been published to date regarding radiochemistry, most of them have been designed for those who major in subjects related to chemistry or physics and use rather sophisticated methods and apparatus. Education about radiation and radioactivity is also very important for other students because a basic knowledge of radiation and radioactivity is indispensable for understanding environmental problems or energy problems in the future. However, it is not easy to conduct practical work using radioactivity in students' experiments at school or at university because the use of radioactivity is strictly regulated by the law, and equipment such as radiation counters is too expensive for school budgets. From such a viewpoint, we developed several kinds of safe and inexpensive experiments for education using natural radioactivity so that university (or senior high school) students can learn through their practical work without being regulated by the law. For this purpose, radioactive species belonging to the uranium decay series are suitable because these species can be easily obtained from mineral spring water or soil samples. In addition, some of the species such as 214 Pb and 214 Bi emit beta rays, which are easy to detect, and the half-lives of these which are easy to detect, and the half-lives of these elements can be measured in one or two-hour school activities. This kind of experiment was employed as an ''Educational experiment for radiochemistry'' at Tottori University for nearly fifty students every year. Although the experiment itself was essentially complete, the students did not have the chance to observe how radioactive equilibrium was established. Therefore, we have developed an additional work plan to enable students to observe how 214 Pb and 214 Bi are produced from 222 Rn, and have made this experiment more complete. The educational usefulness of this additional experiment was evaluated and will be presented in section 5. (author)

  19. Soil gas (222Rn, CO2, 4He) behaviour over a natural CO2 accumulation, Montmiral area (Drome, France): geographical, geological and temporal relationships

    International Nuclear Information System (INIS)

    Gal, Frederick; Joublin, Franck; Haas, Hubert; Jean-prost, Veronique; Ruffier, Veronique

    2011-01-01

    The south east basin of France shelters deep CO 2 reservoirs often studied with the aim of better constraining geological CO 2 storage operations. Here we present new soil gas data, completing an existing dataset (CO 2 , 222 Rn, 4 He), together with mineralogical and physical characterisations of soil columns, in an attempt to better understand the spatial distribution of gas concentrations in the soils and to rule on the sealed character of the CO 2 reservoir at present time. Anomalous gas concentrations were found but did not appear to be clearly related to geological structures that may drain deep gases up to the surface, implying a dominant influence of near surface processes as indicated by carbon isotope ratios. Coarse grained, quartz-rich soils favoured the existence of high CO 2 concentrations. Fine grained clayey soils preferentially favoured the existence of 222 Rn but not CO 2 . Soil formations did not act as barriers preventing gas migrations in soils, either due to water content or due to mineralogical composition. No abundant leakage from the Montmiral reservoir can be highlighted by the measurements, even near the exploitation well. As good correlation between CO 2 and 222 Rn concentrations still exist, it is suggested that 222 Rn migration is also CO 2 dependent in non-leaking areas - diffusion dominated systems.

  20. Doses from {sup 222}Rn, {sup 226}Ra, and {sup 228}Ra in groundwater from Guarani aquifer, South America

    Energy Technology Data Exchange (ETDEWEB)

    Bonotto, D.M. E-mail: dbonotto@rc.unesp.br

    2004-07-01

    Groundwater samples were analysed for {sup 222}Rn, {sup 226}Ra, and {sup 228}Ra in Guarani aquifer spreading around 1 million km{sup 2} within four countries in South America, and it was found that their activity concentrations are lognormally distributed. Population-weighted average activity concentration for these radionuclides allowed to estimate a value either slightly higher (0.13 mSv/year) than 0.1 mSv for the total effective dose or two times higher (0.21 mSv/year) than this limit, depending on the choice of the dose conversion factor. Such calculation adds useful information for the appropriate management of this transboundary aquifer that is socially and economically very important to about 15 million inhabitants living in Brazil, Argentina, Uruguay and Paraguay.

  1. Design of real-time monitoring and control system of 222Rn/220Rn sampling for radon chamber

    International Nuclear Information System (INIS)

    Wu Rongyan; Zhao Xiuliang; Zhang Meiqin; Yu Hong

    2008-01-01

    This paper describes the design of 222 Rn/ 220 Rn sampling monitoring and control system based on single-chip microcomputer of series Intel51. The hardware design involves the choosing and usage of sensors-chips, A/D conversion-chip, USB interface-chip, keyboard-chip, digital display-chip, photoelectric coupling isolation-chips and drive circuit-chips of the direct current pump. Software design is composed by software of Personal Computer (PC) and software of Single Chip Microcomputer (SCM). The data acquisition and conversion and the flux control of direct current pump are realized by using soft of Visual Basic and assemble language. The program flow charts are given. Furthermore, we improved the stability of the direct current pump by means of PID Control Algorithms. (authors)

  2. Possibility of rapidly reporting 226Ra activity in 226Ra-222Rn samples with unknown equilibrium factor by γ spectrometer

    Institute of Scientific and Technical Information of China (English)

    SU Qiong; ZHENG Rui; CHEN Yong; CHENG Jian-Ping

    2004-01-01

    This paper reports the observed changes for equilibrium factors between 226Ra and 222Rn with sealing time of the samples. The samples include soil, raw coal, mineral water, cement, rock, etc. Especially the conceptions of "pre-equilibrium time" and "pre-equilibrium factor" have been put forward and methods of measuring and processing data have been given which can be used for rapidly reporting activity of 226Ra in samples with unknown equilibrium factor. It is definitely concluded that, using methods given in the paper, a test report will be completed in 3~7days, instead of one month, after receiving the sample whose activity is not lower than LLD of the spectrometer.

  3. Current issues and ways to reduce the negative impact of environment increased concentrations of Radon (222Rn)

    International Nuclear Information System (INIS)

    Coretchi, Liubov; Bahnarel, Ion; Apostol, Ion; Virlan, Serghei

    2012-01-01

    (This study was conducted to review the latest research in radon problem carried out by scientists of Moldova, the 13 EU countries and the USA, and relevant international organizations. Particular attention was paid to contradictions between energy efficiency measures and these of mitigation of 222 Rn negative impact on human health. The main proposals developed were focused on the need for a National Radon Strategy (NRS) and a National Action Plan (NAP) for NRS implementation. Both NRS and NAP has to be correlated with other national policies, such as Smoking Reducing or Energy Efficiency. Development of a Radon Database including a map of radon concentrations, as well as a set of requirements for new housing construction, would be among the main components of NAP. (authors)

  4. Proposal for the classification of closed indoor spaces according to concentration of 222Rn and the possible doses involved

    International Nuclear Information System (INIS)

    Espinoza, Marco; Leon, Kety; Martinez, Jorge

    2014-01-01

    Radon causes more than 50 % of total dose from natural background radiation per year. It is widely demonstrated the capacity of radon to induce lung cancer in people exposed to this radioactive gas for long periods. Radon emerges continuously from materials that constitute soils, building materials and minerals present in our natural environment, all over the world. In our country, it is necessary to get better regulations to control the exposition of people to this gas inside buildings, dwellings and facilities where people spend their time. Our country has very simple and scarce regulations on this respect. At present, national regulations about radon are adaptations of recommendations and guides published for international organizations but without national studies or statistics to give realistic support to those rules. This work propose a classification for closed spaces where people live and work in this country taking into consideration their 222 Rn concentration and probable doses involved. (authors).

  5. Experimental study to optimize time resolution and detection limit of online 222Rn-in-water measurements

    International Nuclear Information System (INIS)

    Just, G.; Freyer, K.; Treutler, H.C.; Philipsborn, H. von

    2001-01-01

    The possibility to detect short-term variations of the activity concentration of 222 Rn in water by online monitoring with temporal resolutions of a few minutes and a lower limit of detection of about 1 Bq/l enhances the applicability of such measurements. New applications would be possible in the field of hydro-geology in which Rn is used as tracer gas, the monitoring of pumping procedures, for the study of exchange processes during groundwater sampling and for various applications with geophysical effects. A suitable, simple method is the measuring principle proposed by Surbeck (Fribourg) some years ago which is based on the separation of air and water by a diffusion membrane. Process parameters enhancing the time resolution of the method as well as the efficiency of different radon detectors have been studied. (orig.) [de

  6. Assessment of natural radium isotopes and 222Rn in water samples from Cananeia-Iguape estuarine complex, Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Oliveira, Joselene de; Jesus, Sueli Carvalho de; Abrahao, Fernanda Franco; Santos, Glorivania Ferreira dos; Braga, Elisabete de Santis; Chiozzini, Vitor

    2009-01-01

    Radium isotopes and radon are among the most important natural radionuclides in the environment from both radioprotection and geo-hydrological points of view. These radionuclides are a powerful tool for studying coastal processes and have been used intensively as tracers of groundwater sources that discharge into the ocean. In this paper, naturally occurring radium isotopes and 222 Rn were determined to trace water exchange and SGD in Cananeia-Iguape estuarine complex, a shallow coastal plain estuary in southern Sao Paulo area. The research work was carried out during the first semester of 2009 and covered stations located both in Cananeia and Iguape outlets, as well as samples collected in Ribeira of Iguape River and groundwater. Activity concentrations of 226 Ra in estuarine waters from Cananeia outlet varied from 2.9 mBq L -1 to 4.7 mBq L -1 , while 228 Ra concentrations ranged from 22 mBq L -1 to 45 mBq L -1 . In Iguape outlet, activities of 226 Ra ranged from 1.6 mBq L -1 to 6.6 mBq L -1 ; 228 Ra varied from 13 mBq L -1 to 20 mBq L -1 . Activities of Ra were slightly higher in samples collected at 5 m depth than at the surface water level. Groundwater activity concentrations of 226 Ra ranged from 0.63 mBq L -1 to 12 mBq L -1 and for 228 Ra from 18 mBq L -1 to 39 mBq L -1 . In groundwater, the 228 Ra/ 226 Ra activity ratios varied from 3.3 to 31.7. 222 Rn activities in groundwater up to 747 Bq L -1 were observed. Increased nitrate contents were observed in groundwater samples collected in Cananeia and Comprida Island. (author)

  7. Evaluation of 222Rn concentration of the internal and external environments of residences at Monte Alegre municipality, Para, Brazil

    International Nuclear Information System (INIS)

    Melo, Vicente de Paula

    1999-01-01

    The human being is constantly exposed to the natural radioactivity in the environment where he lives. This radioactivity comes mainly from materials present in the terrestrial crust that possess in their constitution chemical elements belonging to the radioactive families of uranium and thorium. The use of such materials for the construction of houses constitutes an important exposure form to the natural radiation, above all to the radioactive gas 222 Rn, that it is exhaled from them. The Brazilian soil is composed, among other, of minerals that contain appreciable concentrations of these elements. The inhabitants of Monte Alegre town in Para, located at 2 deg 00' 24,9 'S ; 54 deg 04 ' 13,5 W , used in the construction of their houses stones obtained from an area 20 km distant of Monte Alegre, denominated Ingles de Souza, located at 01 deg 56' 4 0,1 S; 54 deg 12 149,7 W, where a small residential village, denominated National Agricultural Colony of Para (CANP), is located. The objective of this work was to evaluate the indoor concentration of 222 Rn in the residences of Monte Alegre and CANP. Determinations of the 238 U and 226 Ra concentrations, measurements of the radon flux in samples of stones and soils of the two regions, as well as measurements to the gamma dose close of the soil and inside the residences, were also carried out. The average results of the radon concentration in the air of the investigated residences did not exceed the limits of 200 Bq. m 3 (action level) and 600 Bq. m 3 (intervention level) recommended by the International Commission on Radiological Protection (ICRP). The concentrations of natural radionuclides and the radon flux determined at the village showed values 17 times higher than those found at the urban area of Monte Alegre, while the average indoor gamma dose rate in the village residences was 0.86 mSv/a. (author)

  8. Temporal 222Rn distributions to reveal groundwater discharge into desert lakes: Implication of water balance in the Badain Jaran Desert, China

    Science.gov (United States)

    Luo, Xin; Jiao, Jiu Jimmy; Wang, Xu-sheng; Liu, Kun

    2016-03-01

    How lake systems are maintained and water is balanced in the lake areas in the Badain Jaran Desert (BJD), northeast of China have been debated for about a decade. In this study, continuous 222Rn measurement is used to quantify groundwater discharge into two representative fresh and brine water lakes in the desert using a steady-state mass-balance model. Two empirical equations are used to calculate atmospheric evasion loss crossing the water-air interface of the lakes. Groundwater discharge rates yielded from the radon mass balance model based on the two empirical equations are well correlated and of almost the same values, confirming the validity of the model. The fresh water and brine lakes have a daily averaged groundwater discharge rate of 7.6 ± 1.7 mm d-1 and 6.4 ± 1.8 mm d-1, respectively. The temporal fluctuations of groundwater discharge show similar patterns to those of the lake water level, suggesting that the lakes are recharged from nearby groundwater. Assuming that all the lakes have the same discharge rate as the two studied lakes, total groundwater discharge into all the lakes in the desert is estimated to be 1.59 × 105 m3 d-1. A conceptual model of water balance within a desert lake catchment is proposed to characterize water behaviors within the catchment. This study sheds lights on the water balance in the BJD and is of significance in sustainable regional water resource utilization in such an ecologically fragile area.

  9. Evaluation of {sup 222}Rn concentration of the internal and external environments of residences at Monte Alegre municipality, Para, Brazil; Avaliacao da concentracao do {sup 222}Rn nos ambientes internos e externos de residencias do municipio de Monte Alegre, PA

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Vicente de Paula

    1999-07-01

    The human being is constantly exposed to the natural radioactivity in the environment where he lives. This radioactivity comes mainly from materials present in the terrestrial crust that possess in their constitution chemical elements belonging to the radioactive families of uranium and thorium. The use of such materials for the construction of houses constitutes an important exposure form to the natural radiation, above all to the radioactive gas {sup 222}Rn, that it is exhaled from them. The Brazilian soil is composed, among other, of minerals that contain appreciable concentrations of these elements. The inhabitants of Monte Alegre town in Para, located at 2 deg 00' 24,9 'S ; 54 deg 04 ' 13,5 {sup W}, used in the construction of their houses stones obtained from an area 20 km distant of Monte Alegre, denominated Ingles de Souza, located at 01 deg 56' 4 0,1 S; 54 deg 12 149,7 W, where a small residential village, denominated National Agricultural Colony of Para (CANP), is located. The objective of this work was to evaluate the indoor concentration of {sup 222}Rn in the residences of Monte Alegre and CANP. Determinations of the {sup 238}U and {sup 226}Ra concentrations, measurements of the radon flux in samples of stones and soils of the two regions, as well as measurements to the gamma dose close of the soil and inside the residences, were also carried out. The average results of the radon concentration in the air of the investigated residences did not exceed the limits of 200 Bq. m{sup 3} (action level) and 600 Bq. m{sup 3} (intervention level) recommended by the International Commission on Radiological Protection (ICRP). The concentrations of natural radionuclides and the radon flux determined at the village showed values 17 times higher than those found at the urban area of Monte Alegre, while the average indoor gamma dose rate in the village residences was 0.86 mSv/a. (author)

  10. Monitoring network of atmospheric Radon-222 concentration in East Asia and backward trajectory analysis of Radon-222 concentration trend at a small solitary island on pacific ocean

    International Nuclear Information System (INIS)

    Ohkura, Takehisa; Yamazawa, Hiromi; Moriizumi, Jun; Hirao, Shigekazu; Iida, Takao; Guo Qiuju; Tohjima, Yasunori

    2009-01-01

    A monitoring network of atmospheric 222 Rn concentration as a tracer for long-range transport in East Asia was established. Atmospheric 222 Rn concentration at Beijing, which is located on China Continent was 10-20 Bq m -3 , at Nagoya, which is located on edge of terrestrial area was 3-10 Bq m -3 and at Hachijo-jima and Hateruma-jima, which are solitary islands in Pacific Ocean was 0.5-3 Bq m -3 , respectively. The atmospheric 222 Rn concentration variations were different from sites. The 222 Rn concentration was the lowest in the summer and the highest in the winter except Nagoya where the highest was observed in the autumn and the lowest in the spring. Diurnal variations were measured at Beijing and Nagoya. In contrast, diurnal variations were not measured but several-day-cycle variations were measured at Hachijo-jima and Hateruma-jima. It was pointed out by this study that the several-day-cycle variations at Hachijo-jima were dependent on synoptic-scale atmospheric disturbance. 222 Rn concentration increased rapidly after a cold front passed through Hachijo-jima. Backward trajectory analysis of the relationship between atmospheric 222 Rn concentrations at Hachijo-jima and transport pathway of air mass indicates that air mass transported from China and Siberia has high concentration 222 Rn and air mass transported from Pacific Ocean has low concentration 222 Rn. In winter, atmospheric 222 Rn concentrations at Hachijo-jima is dependent on vertical transport pathway rather than horizontal transport pathway. (author)

  11. 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

  12. Measurement of Radon (222Rn) in the High School of Medicine 'Dr.Ali Sokoli' in Prishtina

    International Nuclear Information System (INIS)

    Kadiri, S.; Hodolli, G.; Pllana, X.; Dumani, S.; Hasani, F.

    2011-01-01

    Measurements of radon concentration (222Rn) were performed in the largest High School of Medicine ''Dr. Ali Sokoli'' in Prishtina. We choose four locations (classrooms) at ground level, three at first and three on the second floor. In the same premises, the measurements were performed with two methods: using a scintillation cell and a continuous method. The maximum value of radon concentration, measurements with scintillation cells, were obtained by the ground level moving to (573 ± 26) Bq m -3 , while the minimum value of (176 ± 11) Bq m -3 was obtained in the second floor. The maximum value of radon concentration measurements with the continuous method was 116 Bq m -3 in ground level, and the minimum value was 70 Bq m -3 . Based on these results, we calculated annual effective dose, which ranges between (0.76 ± 0.06) mSv and (2.48 ± 0.11) mSv, by scintillation cells. Whereas, the annual effective dose measuring by continuous method was between 0.30 mSv and 0.50 mSv. Based on those results, we conclude that radon concentration and annual effective doses were within accepted international standards. (author)

  13. A simple method for calibration of Lucas scintillation cell counting system for measurement of 226Ra and 222Rn

    Directory of Open Access Journals (Sweden)

    N.K. Sethy

    2014-10-01

    Full Text Available Known quantity of radium from high grade ore solution was chemically separated and carefully kept inside the cavity of a Lucas Cell (LC. The 222Rn gradually builds up and attain secular equilibrium with its parent 226Ra. This gives a steady count after a suitable buildup period (>25 days. This secondary source was used to calibrate the radon counting system. The method is validated in by comparison with identical measurement with AlphaGuard Aquakit. The radon counting system was used to evaluate dissolved radon in ground water sample by gross alpha counting in LC. Radon counting system measures the collected radon after a delay of >180 min by gross alpha counting. Simultaneous measurement also carried out by AlphaGuard Aquakit in identical condition. AlphaGuard measures dissolved radon from water sample by constant aeration in a closed circuit without giving any delay. Both the methods are matching with a correlation coefficient of >0.9. This validates the calibration of Lucas scintillation cell counting system by designed encapsulated source. This study provides an alternative for calibration in absence of costly Radon source available in the market.

  14. Effects of barium chlorine treatment of uranium ore on 222Rn emanation and 226Ra leachability from mill tailings

    International Nuclear Information System (INIS)

    Ibrahim, S.A.; Church, S.L.; Whicker, F.W.

    1985-01-01

    The purpose of this laboratory study was to investigate the effectiveness of barium chloride treatment of uranium ore on 222 Rn emanation from mill tailings, 226 Ra level in waste-water, and the leachability of radium from tailings. It has been shown that barium sulfate is an excellent carrier for radium and that barium sulfate crystals have high retention capacity for radon gas produced by radium trapped within the lattice. Ground uranium ore from a mine in Wyoming was mixed with water to form a 1:1 ratio before barium and potassium chlorides were added at concentrations of 0, 10, 25, 50, and 100 mg per liter of slurry. The ore was then subjected to a simulated mill process using sulfuric acid leaching. The liquid representing tailings pond water was separated and analyzed for 226 Ra and the solid fraction, representing mill tailings, was tested for radon emanation and the leachability of radium by deionized water. This study suggests that barium treatment of uranium ore prior to sulfuric acid leaching could be effective in reducing radon emanation from tailings and also in reducing the 226 Ra concentration of waste-water. Leachability of radium from treated tailings was markedly reduced

  15. Studies on 222Rn concentration in ground water using smart radon monitor and assessment of the radiation dose to the population of Mysuru city

    International Nuclear Information System (INIS)

    Chandrashekara, M.S.; Pruthvi Rani, K.S.

    2017-01-01

    Radioactive elements originate from the earth's crust and make their way into air, water, food and eventually in to the living system. Even though 75% of the Earth's surface is covered by water, only about 0.3 % of the total water on the Earth is available for public use. The ground water contains trace amounts of radioactive elements and these radionuclides contribute significant amount of dose to living beings, through intake of water into the human body. Radon dissolved in water is released into air when it is used for cooking, drinking, bathing and washing purposes. Exposure of population to higher concentrations of radon and its progeny for a long time causes occurrence of lung cancer and pathological effects like respiratory functional changes. Radon is a main source of ionizing radiation of natural origin and the studies on radon concentrations in drinking water are of importance. A systematic study of 226 Ra and 222 Rn concentration in the drinking water samples was carried out in Mysuru city. The concentration of 226 Ra and 222 Rn was estimated in water samples using emanometry method employing scintillation cells and alpha counting system. The 222 Rn concentration in water was also measured using a Smart Radon Monitor (SRM) for comparison of the results. SRM is a technologically advanced real time, portable, radon monitor developed at BARC, Mumbai

  16. Natural 222Rn and 220Rn indicate the impact of the Water–Sediment Regulation Scheme (WSRS) on submarine groundwater discharge in the Yellow River estuary, China

    International Nuclear Information System (INIS)

    Xu, Bochao; Xia, Dong; Burnett, William C.; Dimova, Natasha T.; Wang, Houjie; Zhang, Longjun; Gao, Maosheng; Jiang, Xueyan; Yu, Zhigang

    2014-01-01

    Highlights: • 220 Rn and 222 Rn were combined to locate intensive SGD sites. • Influence of WSRS to SGD was found for the first time. • SGD was a dominant nutrient pathway in the Yellow River estuary. - Abstract: Submarine groundwater discharge (SGD) in estuaries brings important influences to coastal ecosystems. In this study, we observed significant SGD in the Yellow River estuary, including a fresh component, during the Water–Sediment Regulation Scheme (WSRS) period. We used the 222 Rn and 220 Rn isotope pair to locate sites of significant SGD within the study area. Three apparent SGD locations were found during a non-WSRS period, one of which became much more pronounced, according to the remarkably elevated radon levels, during the WSRS. Increased river discharge (from 245 m 3 s −1 to 3560 m 3 s −1 ) and the elevated river water level (from 11 m to 13 m) during the WSRS led to a higher hydraulic head, enhancing groundwater discharge in the estuary. Our results suggest that high river discharge (>3000 m 3 s −1 ) might be necessary for elevated fresh submarine groundwater discharging (FSGD). Vertical profiles of salinity, DO and turbidity anomalies along the benthic boundary layer also indicated significant FSGD in the estuary during the WSRS. Nutrient concentrations had positive correlations with 222 Rn during a 24-h observation, which indicates that SGD is a dominant nutrient pathway in this area

  17. Indoor {sup 22}Rn and {sup 222}Rn concentration measurements inside the Teotihuacan pyramids using NTD and E-PERM methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa, G. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000 Mexico, D.F. (Mexico)]. E-mail: espinosa@fisica.unam.mx; Golzarri, J.I. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000 Mexico, D.F. (Mexico); Martinez, T. [Facultad de Quimica, UNAM, Edificio D, Ciudad Universitaria, Mexico, D.F. (Mexico); Navarrete, M. [Facultad de Quimica, UNAM, Edificio D, Ciudad Universitaria, Mexico, D.F. (Mexico); Bogard, J. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6480 (United States); Martinez, G. [Coordinacion Nacional de Conservacion del Patrimonio Cultural, Xicotencatl y General Anaya s/n, 04120 Mexico, D.F. (Mexico); Juarez, F. [Instituto de Geofisica, UNAM, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico)

    2005-11-15

    Measurements of {sup 22}Rn (Thoron) and {sup 222}Rn (Radon) concentrations, inside the Sun and Moon pyramids of Teotihuacan's archeological zone in Mexico, are reported in this work. Two well-established methods, nuclear track detectors (NTDs), using open-close end cups with internal and external detectors of CR-39 polymer, and electret-passive environmental radon monitoring (E-PERM) were used for the measurements. This experiment had two objectives: to obtain better confidence in the {sup 22}Rn and {sup 222}Rn measurements inside the archeological tunnels, and to compare the data obtained in each one of the two methods. This experiment is specially interesting because of the very peculiar conditions where the measurements are made: high humidity, labyrinths with air currents, but almost constant temperature inside of the pyramid tunnels and galleries, notwithstanding of the temperature changes between the day and the night outside of the pyramid body. The {sup 222}Rn concentrations found in both the pyramids were lower than the action level proposed by the ICRP-65. These tunnels are not open to the public, but researchers from the Anthropology Institutions spend part of their time working there, in periods varying from 3 to 5 months.

  18. Testing the usefulness of 222Rn to complement conventional hydrochemical data to trace groundwater provenance in complex multi-layered aquifers. Application to the Úbeda aquifer system (Jaén, SE Spain).

    Science.gov (United States)

    Ortega, L; Manzano, M; Rodríguez-Arévalo, J

    2017-12-01

    The Úbeda aquifer system is a multi-layered aquifer intensively exploited for irrigation. It covers 1100km 2 and consists of piled up sedimentary aquifer and aquitard layers from Triassic sandstones and clays at the bottom, to Jurassic carbonates (main exploited layer) in the middle, and Miocene sandstones and marls at the top. Flow network modification by intense exploitation and the existence of deep faults favour vertical mixing of waters from different layers and with distinct chemical composition. This induces quality loss and fosters risk of quantity restrictions. To support future groundwater abstraction management, a hydrogeochemical (major and some minor solutes) and isotopic ( 222 Rn) study was performed to identify the chemical signatures of the different layers and their mixing proportions in mixed samples. The study of 134 groundwater samples allowed a preliminary identification of hydrochemical signatures and mixtures, but the existence of reducing conditions in the most exploited sector prevents the utility of sulphate as a tracer of Triassic groundwater in the Jurassic boreholes. The potential of 222 Rn to establish isotopic signatures and to trace groundwater provenance in mixtures was tested. 222 Rn was measured in 48 samples from springs and boreholes in most aquifer layers. At first, clear correlations were observed between 222 Rn, Cl and SO 4 in groundwater. Afterwards, very good correlations were observed between 222 Rn and the chemical facies of the different layers established with End Member Mixing Analysis (EMMA). Using 222 Rn as part of the signatures, EMMA helped to identify end-member samples, and to quantify the mixing proportions of water from the Triassic and the Deep Miocene layers in groundwater pumped by deep agricultural wells screened in the Jurassic. The incorporation of 222 Rn to the study also allowed identifying the impact of irrigation returns through the association of moderate NO 3 , Cl, and Br contents with very low 222

  19. {sup 222} Rn exposure assessment in the caves of Parque Estadual Turistico do Alto Ribeira (PETAR); Avaliacao da exposicao ao {sup 222} Rn nas cavernas do Parque Estadual Turistico do Alto Ribeira (PETAR)

    Energy Technology Data Exchange (ETDEWEB)

    Alberigi, Simone

    2006-07-01

    In the present work, radon concentrations in six caves of PETAR - Parque Estadual Turistico do Alto Ribeira (High Ribeira River Touristic State Park) were carried out with Makrofol E solid state nuclear track detectors (SSNTD) and used to assess the annual effective dose received by regional tour guides. The park has four visitation centers: Santana, Ouro Grosso, Caboclos e Casa de Pedra and receives nearly 40,000 people annually. The caves evaluated were Couto, Agua Suja, Laje Branca, Morro Preto and Santana, from Santana center and Alambari de Baixo from Ouro Grosso center, for being the most frequently visited caves. The exposure period of the SSNTD was, at least, three months, over a period of 26 months, from October 2003 to November 2005.The {sup 222}Rn concentrations lay in a range from 153 Bq.m{sup -3} to 6607 Bq.m{sup -3} and we observed that, in general, for chilly weather, the radon levels decrease. The annual effective dose, considering the most realistic scenario, with geometric mean concentrations, an equilibrium factor of 0.5 and annual exposure time for each cave, varied from 0.2 mSv.a{sup -1} for the Couto cave, strongly ventilated, to 4.0 mSv.a{sup -1} for the Santana cave, the most frequently visited and no external communication. For the worst scenario, with arithmetic mean concentrations, equilibrium factor 1 and annual exposure time for all caves, the annual effective dose was 16.1 mSv.a{sup -1}. All assessed effective doses received by the tour guides are bellow 20 mSv.a{sup -1} suggested as an annual effective dose limit for occupational exposure by the International Commission of Radiological Protection (ICRP 60, 1990). (author)

  20. Express determination of the volume 222Rn activity using the Lucas Type scintillation cells

    International Nuclear Information System (INIS)

    Muellerova, M.; Holy, K.; Polaskova, A.

    2006-01-01

    This report deals with the possibility of the accurate determination of the volume radon activity using the Lucas type scintillation chamber before the radioactive equilibrium between the radon and its decay products is achieved. This method allows to obtain data about the volume activity of the sample promptly and also it offers a possibility to apply the detector for measurements more times a day. We developed a method for the determination of the detection efficiency of the scintillation chamber for varied time periods after the chamber was filled up with a sample. The volume radon activity calculated from the count rates in saturated conditions is in a good agreement with the volume radon activity calculated from our derived relation. It was shown that the scintillation chamber can be used for the express determination of the volume radon activity. The time between the individual applications of the scintillation chamber can be compressed maintaining of sufficient accuracy of the determination of the volume radon activity. (authors)

  1. Measurement of the {sup 22R}n concentration in residences and workplaces in the Riobamba City; Medicion de la concentracion de {sup 222}Rn en residencias y lugares de trabajo en la Ciudad de Riobamba

    Energy Technology Data Exchange (ETDEWEB)

    Cuadrado, C.; Carrasco, J., E-mail: coralia_cuadrado@hotmail.com [Escuela Superior Politecnica de Chimborazo, Facultad de Ciencias, Panamericana Sur Km 1 1/2, EC060155 Riobamba (Ecuador)

    2016-10-15

    The {sup 222}Rn belongs to the {sup 238}U natural radioactive series, decays emitting alpha particles with a disintegration half-period of 3.82 days. Is a colorless and odorless gas that is imperceptible to people. Studies have shown that indoor radon exposure can lead to lung cancer, even for the relatively low levels of radon commonly found in residential buildings. Measurements of the radon concentration were carried out in residences, offices and university laboratories in the Riobamba City (Ecuador), characterizing the places by the building materials, their age, length of stay among other variables. A Corentium brand electronic detector was used, which gives a short reading in 24 hours and extended in 7 days. Using the radon dose conversion coefficient 0.017 mSv/y for 1 Bq/m{sup 3}, recommended by the ICRP annual doses were estimated for each site. The data obtained show that the ranges are acceptable and are within the Who recommendations, being out of range a teaching laboratory because it has natural uranium for practices. These measurements are the first to be carried out in the country and can be used to promote research of this type at local, national and regional level. (Author)

  2. Development of an integrated sampler based on direct 222Rn/220Rn progeny sensors in flow-mode for estimating unattached/attached progeny concentration

    International Nuclear Information System (INIS)

    Mishra, Rosaline; Sapra, B.K.; Mayya, Y.S.

    2009-01-01

    A flow-mode integrated sampler consisting of a wire-mesh and filter-paper array along with passive solid state nuclear track detectors has been developed for estimating unattached and attached fraction of 222 Rn/ 220 Rn progeny concentration. The essential element of this sampler is the direct 222 Rn/ 220 Rn progeny sensor (DRPS/DTPS), which is an absorber-mounted-LR115 type nuclear track detector that selectively registers the alpha particles emitted from the progeny deposited on its surface. During sampling at a specified flow-rate, the unattached progeny is captured on the wire-mesh; while the attached progeny gets transmitted and is captured on the filter-paper. The alpha particles emitted by the deposited progeny atoms are registered on the sensors placed at a specified distance facing the wire-mesh and the filter-paper, respectively. The various steps involved in the development of this flow-mode direct progeny sampler such as the optimization of the sampling rate and the distance between the sensor and the deposition substrate are discussed. The sensitivity factor of the DTPS-loaded sampler for 220 Rn progeny deposited on the wire-mesh and filter-paper is found to be 23.77 ± 0.64 (track cm -2 h -1 ) (Bq m -3 ) -1 and 22.30 ± 0.18 (track cm -2 h -1 ) (Bq m -3 ) -1 , respectively; while that of DRPS-loaded sampler for 222 Rn progeny deposition, is 3.03 ± 0.14 (track cm -2 h -1 ) (Bq m -3 ) -1 and 2.08 ± 0.07 (track cm -2 h -1 ) (Bq m -3 ) -1 , respectively. The highlight of this flow-mode sampler is its high sensitivity and that it utilizes the passive technique for estimating the unattached and attached progeny concentration, thus doing away with the alpha counting procedures.

  3. Extensive radioactive characterization of a phosphogypsum stack in SW Spain: {sup 226}Ra, {sup 238}U, {sup 210}Po concentrations and {sup 222}Rn exhalation rate

    Energy Technology Data Exchange (ETDEWEB)

    Abril, Jose-Maria, E-mail: jmabril@us.es [Dpto. Fisica Aplicada I, Universidad de Sevilla, EUITA, Ctra Utrera Km 1, 41013 Seville (Spain); Garcia-Tenorio, Rafael, E-mail: gtenorio@us.es [Dpto. Fisica Aplicada II, Universidad de Sevilla, ETSA, Avda. Reina Mercedes s/n, 41012 Seville (Spain); Manjon, Guillermo, E-mail: manjon@us.es [Dpto. Fisica Aplicada II, Universidad de Sevilla, ETSA, Avda. Reina Mercedes s/n, 41012 Seville (Spain)

    2009-05-30

    Phosphogypsum (PG) is a by-product of the phosphate fertilizer industries that contains relatively high concentrations of uranium series radionuclides. The US-EPA regulates the agriculture use of PG, attending to its {sup 226}Ra content and to the {sup 222}Rn exhalation rate from inactive stacks. Measurements of {sup 222}Rn exhalation rates in PG stacks typically show a large and still poorly understood spatial and temporal variability, and the published data are scarce. This work studies an inactive PG stack in SW Spain of about 0.5 km{sup 2} from where PG can be extracted for agriculture uses, and an agriculture soil 75 km apart, being representative of the farms to be amended with PG. Activity concentrations of {sup 226}Ra, {sup 238}U and {sup 210}Po have been measured in 30 PG samples (0-90 cm horizon) allowing for the construction of maps with spatial distributions in the PG stack and for the characterization of the associated PG inputs to agriculture soils. Averaged {sup 226}Ra concentrations for the stack were 730 {+-} 60 Bq kg{sup -1} (d.w.), over the US-EPA limit of 370 Bq kg{sup -1}. {sup 222}Rn exhalation rate has been measured by the charcoal canister method in 49 sampling points with 3 canisters per sampling point. Values in PG stack were under the US-EPA limit of 2600 Bq m{sup -2} h{sup -1}, but they were one order of magnitude higher than those found in the agriculture soil. Variability in radon emissions has been studied at different spatial scales. Radon exhalation rates were correlated with {sup 226}Ra concentrations and daily potential evapotranspiration (ETo). They increased with ETo in agriculture soils, but showed an opposite behaviour in the PG stack.

  4. Mapping and quantifying groundwater inflows to Deep Creek (Maribyrnong catchment, SE Australia) using 222Rn, implications for protecting groundwater-dependant ecosystems

    International Nuclear Information System (INIS)

    Cartwright, Ian; Gilfedder, Benjamin

    2015-01-01

    Highlights: • Groundwater inflows in a chain-of-ponds river quantified. • Groundwater inflow vs. discharge relationship determined using Rn. • First long-term continuous Rn monitoring in a river indicates temporal changes to groundwater inflows. • Application to protection of groundwater-dependant ecosystems. - Abstract: Understanding groundwater inflows to rivers is important in managing connected groundwater and surface water systems and for protecting groundwater-dependant ecosystems. This study defines the distribution of gaining reaches and estimates groundwater inflows to a 62 km long section of Deep Creek (Maribyrnong catchment, Australia) using 222 Rn. During summer months, Deep Creek ceases to flow and comprises a chain of ponds that δ 18 O and δ 2 H values, major ion concentrations, and 222 Rn activities imply are groundwater fed. During the period where the river flows, the relative contribution of groundwater inflows to total river discharge ranges from ∼14% at high flow conditions to ∼100% at low flows. That the predicted groundwater inflows account for all of the increase in discharge at low flow conditions lends confidence to the mass balance calculations. Near-continuous 27 week 222 Rn monitoring at one location in the middle of the catchment confirms the inverse correlation between river discharge and relative groundwater inflows, and also implies that there are limited bank return flows. Variations in groundwater inflows are related to geology and topography. High groundwater inflows occur where the river is at the edge of its floodplain, adjacent to hills composed of basement rocks, or flowing through steep incised valleys. Understanding the distribution of groundwater inflows and quantifying the contribution of groundwater to Deep Creek is important for managing and protecting the surface water resources, which support the endangered Yarra pygmy perch

  5. Examining the spatial and temporal variation of groundwater inflows to a valley-to-floodplain river using 222Rn, geochemistry and river discharge: the Ovens River, southeast Australia

    Science.gov (United States)

    Yu, M. C. L.; Cartwright, I.; Braden, J. L.; de Bree, S. T.

    2013-12-01

    Radon (222Rn) and major ion geochemistry were used to define and quantify the catchment-scale groundwater-surface water interactions along the Ovens River in the southeast Murray-Darling Basin, Victoria, Australia, between September 2009 and October 2011. The Ovens River is characterized by the transition from a single channel within a mountain valley in the upper catchment to a multi-channel meandering river on flat alluvial plains in the lower catchment. Overall, the Ovens River is dominated by gaining reaches, receiving groundwater from both alluvial and basement aquifers. The distribution of gaining and losing reaches is governed by catchment morphology and lithology. In the upper catchment, rapid groundwater recharge through the permeable aquifers increases the water table. The rising water table, referred to as hydraulic loading, increases the hydraulic head gradient toward the river and hence causes high baseflow to the river during wet (high flow) periods. In the lower catchment, lower rainfall and finer-gained sediments reduce the magnitude and variability of hydraulic gradient between the aquifer and the river, producing lower but more constant groundwater inflows. The water table in the lower reaches has a shallow gradient, and small changes in river height or groundwater level can result in fluctuating gaining and losing behaviour. The middle catchment represents a transition in river-aquifer interactions from the upper to the lower catchment. High baseflow in some parts of the middle and lower catchments is caused by groundwater flowing over basement highs. Mass balance calculations based on 222Rn activities indicate that groundwater inflows are 2 to 17% of total flow with higher inflows occurring during high flow periods. In comparison to 222Rn activities, estimates of groundwater inflows from Cl concentrations are higher by up to 2000% in the upper and middle catchment but lower by 50 to 100% in the lower catchment. The high baseflow estimates using

  6. Update of the BIPM.RI(II)-K1.Rn-222 comparison of activity measurements for the radionuclide {sup 222}Rn to include the LNE-LNHB, France

    Energy Technology Data Exchange (ETDEWEB)

    Michotte, C.; Ratel, G. [Bureau International de Poids et Mesures, Pavillon de Breteuil, F-92312 Sevres cedex (France); Cassette, P. [Bureau International de Poids et Mesures, Pavillon de Breteuil, F-92312 Sevres cedex (France); Laboratoire national de metrologie et d' essais -Laboratoire national Henri Becquerel, 91191 Gif-sur-Yvette cedex (France)

    2012-02-15

    In 2007, the Laboratoire national de metrologie et d'essais - Laboratoire national Henri Becquerel (LNE-LNHB), France submitted a sample of known activity of {sup 222}Rn to the International Reference System (SIR) for comparison. The value of the activity submitted was about 90 kBq. This key comparison result joins that of Switzerland and Germany in the key comparison database that now contains three results, identifier BIPM.RI(II)-K1.Rn-222. Consequently, the KCRV has been updated and the degrees of equivalence with the KCRV have been evaluated. (authors)

  7. Evidence of precursor phenomena in the Kobe earthquake obtained from atmospheric radon concentration

    Energy Technology Data Exchange (ETDEWEB)

    Yasuoka, Yumi [Kobe Pharmaceutical University, 4-19-1 Mtoyamakitama-machi, Higashinada-ku, Kobe, Hyogo 658-8558 (Japan)]. E-mail: yasuoka@kobepharma-u.ac.jp; Igarashi, George [Science Research Center for Prediction of Earthquakes and Volcanic Eruptions, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575 (Japan); Ishikawa, Testuo [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Tokonami, Shinji [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Shinogi, Masaki [Kobe Pharmaceutical University, 4-19-1 Mtoyamakitama-machi, Higashinada-ku, Kobe, Hyogo 658-8558 (Japan)

    2006-06-15

    Atmospheric {sup 222}Rn concentrations were determined over a 10a period, which included the date of the Kobe, Japan earthquake, on January 17th 1995. It was found that the seismically related {sup 222}Rn anomaly was higher than the 99% confidence limits for the residual value of atmospheric {sup 222}Rn which had been observed 2 months before. The residual {sup 222}Rn concentration, in which residual values of the daily minimum are the difference between each normal {sup 222}Rn concentration (calculated from January 1984 to December 1993) and the daily minimum {sup 222}Rn concentration (January 1994 to January 1995), was calculated by applying the exponential smoothing method to the residual values for each day. It was found that the fluctuations of the residual values can be fitted very well to a log-periodic oscillation model. The real residual values stopped increasing at 1994.999 (December 31st 1994), which corresponds with the critical point (t {sub c}) of best fit model. This anomalous {sup 222}Rn variation can be seen as the result of local stresses, not primary stresses which directly lead to the Kobe earthquake. On the other hand, when the critical exponent (z) and the radial frequency ({omega}) of the model were simultaneously fixed 0.2 {<=} z {<=} 0.6 and 6 {<=} {omega} {<=} 12, t {sub c} (critical point) was between January 13th 1995 and January 27th 1995. The Kobe earthquake occurrence date (January 17th 1995) is within this range. Therefore this anomalous {sup 222}Rn variation can also be seen as the result of primary stresses which possibly led to the Kobe earthquake. There is a distinct possibility that similar statistical oscillations will be detected in other measurements such as microseismicity, tectonic strain, fluctuation in the ground level, or changes in groundwater elevations and composition.

  8. Determination of committed effective doses to skin due to 238U, 232Th and 222Rn from the application of various Moroccan black soap (Saboun Beldi) samples by members of the general public

    International Nuclear Information System (INIS)

    Misdaq, M. A.; Outeqablit, K.

    2010-01-01

    238 U, 232 Th, 222 Rn and 220 Rn concentrations were measured inside various Moroccan black soap samples widely used by the Moroccan population in traditional baths (Hammams) by using both CR-39 and LR-115 type II solid state nuclear track detectors. The measured 238 U, 232 Th, 222 Rn and 220 Rn concentrations, respectively, ranged from (3.7±0.2) to (11.7±0.7) mBq kg -1 , (0.11±0.01) to (0.32±0.02) mBq kg -1 , (3.8±0.2) to (11.6±0.6) Bq kg -1 and (0.10±0.01) to (0.31±0.02) Bq kg -1 for the Moroccan black soap samples studied. The influence of pollution on the concentrations of these radionuclides inside the considered Moroccan black soap was investigated. A new dosimetric model for evaluating annual committed effective doses due to 238 U, 232 Th and 222 Rn to the skin of different age groups of the Moroccan populations from the application of the black soap samples studied was developed. The maximum total committed effective dose to the skin due to 238 U, 232 Th and 222 Rn from the application of unpolluted black soap samples 20 min per week by the Moroccan populations was found to be equal to (0.88±0.05) μSv y -1 cm -2 . (authors)

  9. 222Rn and 220Rn concentrations measured in various natural honey samples by using nuclear track detectors and resulting radiation doses to the members of the rural populations in Morocco

    International Nuclear Information System (INIS)

    Misdaq, M. A.; Mortassim, A.

    2008-01-01

    Radon ( 222 Rn) and thoron ( 220 Rn) concentrations were measured in sixteen natural honey material samples collected from different regions in Morocco by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). The concentrations of these radionuclides were also measured in nectar solutions corresponding to the studied honey samples. The measured concentrations of 222 Rn and 220 Rn in honey samples ranged from (2.3 ± 0.2) to (8.1 ± 0.6) Bq.l -1 and (1.8 ± 0.1) to (3.9 ± 0.3) Bq.l -1 , respectively. Committed equivalent doses due to annual intakes of 222 Rn were evaluated in the human gastrointestinal tract compartments of adult members of the Moroccan populations from the ingestion of studied honey samples. The influence of the target tissue mass and activities due to 222 Rn on the annual committed equivalent doses in the compartments of the human gastrointestinal tract was investigated. (authors)

  10. Soil gas ({sup 222}Rn, CO{sub 2}, {sup 4}He) behaviour over a natural CO{sub 2} accumulation, Montmiral area (Drome, France): geographical, geological and temporal relationships

    Energy Technology Data Exchange (ETDEWEB)

    Gal, Frederick, E-mail: f.gal@brgm.f [BRGM, Metrology Monitoring Analysis Department, 3 Avenue Claude-Guillemin, B.P. 36009, 45060 Orleans cedex 2 (France); Joublin, Franck, E-mail: f.joublin@brgm.f [BRGM, Regional Geological Survey, 6 ter, Rue Pierre et Marie Curie, 59260 Lezennes (France); Haas, Hubert, E-mail: h.haas@brgm.f [BRGM, Metrology Monitoring Analysis Department, 3 Avenue Claude-Guillemin, B.P. 36009, 45060 Orleans cedex 2 (France); Jean-prost, Veronique, E-mail: v.jean-prost@brgm.f [BRGM, Metrology Monitoring Analysis Department, 3 Avenue Claude-Guillemin, B.P. 36009, 45060 Orleans cedex 2 (France); Ruffier, Veronique, E-mail: v.ruffier@brgm.f [BRGM, Metrology Monitoring Analysis Department, 3 Avenue Claude-Guillemin, B.P. 36009, 45060 Orleans cedex 2 (France)

    2011-02-15

    The south east basin of France shelters deep CO{sub 2} reservoirs often studied with the aim of better constraining geological CO{sub 2} storage operations. Here we present new soil gas data, completing an existing dataset (CO{sub 2}, {sup 222}Rn, {sup 4}He), together with mineralogical and physical characterisations of soil columns, in an attempt to better understand the spatial distribution of gas concentrations in the soils and to rule on the sealed character of the CO{sub 2} reservoir at present time. Anomalous gas concentrations were found but did not appear to be clearly related to geological structures that may drain deep gases up to the surface, implying a dominant influence of near surface processes as indicated by carbon isotope ratios. Coarse grained, quartz-rich soils favoured the existence of high CO{sub 2} concentrations. Fine grained clayey soils preferentially favoured the existence of {sup 222}Rn but not CO{sub 2}. Soil formations did not act as barriers preventing gas migrations in soils, either due to water content or due to mineralogical composition. No abundant leakage from the Montmiral reservoir can be highlighted by the measurements, even near the exploitation well. As good correlation between CO{sub 2} and {sup 222}Rn concentrations still exist, it is suggested that {sup 222}Rn migration is also CO{sub 2} dependent in non-leaking areas - diffusion dominated systems.

  11. Field and laboratory tests of etched track detectors for 222Rn: summer-vs-winter variations and tightness effects in Maine houses

    International Nuclear Information System (INIS)

    Hess, C.T.; Fleischer, R.L.; Turner, L.G.

    1985-01-01

    Effects of tightness of homes of bedrock character on indoor 222 Rn concentrations were sought in 70 homes in the state of Maine by means of four 6- to 8-month-long surveys over a 1.5-yr period. Laboratory experiments were also performed that document the reliability of the track etching system used for the measurements. In this survey the Rn in tight homes was on the average 3.5 times that in drafty ones, and areas with granitic bedrock led to homes having 2.3 times the Rn as for homes on chlorite-biotite-rich bedrock. Winter-to-summer ratios ranged from 0.5-7, and averaged 1.5, implying that surveys of individual homes require a full year of monitoring

  12. Design and operation of an automated beta-particle counting system for the measurement of 220Rn (and 222Rn) progeny

    International Nuclear Information System (INIS)

    Bigu, J.

    1992-01-01

    A fully automated system of the continuous (active) type has been designed for the unattended quantification of 222 Rn progeny and 220 Rn progeny in calibration and test facilities, as well as working and living environments. The system uses a β-particle detector and associated electronic circuitry, in conjunction with an in-house microprocessor-based processing interface card and a personal computer, operated by specially developed in-house software. The system represents a significant improvement over systems using α-particle detectors because of its enhanced flexibility of design and virtual elimination of plate-out effects in the sampling head, and of self-absorption phenomena in the sampling filter. The β-particle system was tested and calibrated in a Radon and Thoron Test Facility of the walk-in type under a variety of experimental conditions. (author)

  13. Characteristic and Mixing Mechanisms of Thermal Fluid at the Tampomas Volcano, West Java, Using Hydrogeochemistry, Stable Isotope and 222Rn Analyses

    Directory of Open Access Journals (Sweden)

    Irwan Iskandar

    2018-03-01

    Full Text Available The Tampomas Volcano is a Quaternary volcano located on Java Island and controlled by a west-northwest–east-southeast (WNW-ESE regional fault trend. This regional structure acts as conduits for the hydrothermal fluids to ascend from a deeper system toward the surface and, in the end, mix with groundwater. In this research, water geochemistry, gas chemistry and isotopes 2H, 18O and 13C were used to explore the subsurface fluid characteristics and mixing mechanisms of the hydrothermal fluids with groundwater. In addition to those geochemical methods, soil-gas and dissolved 222Rn observations were performed to understand the geological control of fluid chemistry. Based on the analytical results, the hydrothermal system of Tampomas is only developed at the northeastern flank of the volcano, which is mainly controlled by NE-SW structures as deep fluid conduits, while the Cimalaka Caldera Rim around Sekarwangi act as the boundary flow of the system. This system is also categorized as an “intermediate temperature system” wherein fluid is derived from the interaction between the volcanic host-rock at 170 ± 10 °C mixed with trace organic gas input from sedimentary formation; afterwards, the fluid flows laterally and is diluted with groundwater near the surface. Soil-gas and dissolved 222Rn confirm that these permeable zones are effective conduits for the ascending thermal fluids. It is found that NE faults carry higher trace elements from the deeper system, while the circular feature of the Caldera Rim acts as the boundary of the hydrothermal system.

  14. Variations of Rn-222 concentration in the Bratislava air

    International Nuclear Information System (INIS)

    Holy, K.; Bohm, R.; Polaskova, A.

    1996-01-01

    222 Rn is produced by alpha decay of 222 Ra in roil. A small fraction of totally produced 222 Rn escapes from coil particles into soil air. Then 222 Rn is transported predominantly by molecular diffusion into outdoor atmosphere. The radon concentration in the outdoor atmosphere is not stable. It varies irregularly depending on meteorological conditions. However there were found out regular daily and remand variations of 222 Rn concentration in outdoor atmosphere. These variations were measured in numerous works and results are summarized f.e. in work of Gesell. A simple model described the annual variations of 222 Rn concentration war published by Minato. A mathematical analysis of daily course of 222 Rn concentration in outdoor atmosphere was realized by Garzon et al. Some results of our study of 222 Rn variations in outdoor atmosphere of Bratislava are shown in this report. (author)

  15. The influence of the nature of soil and plant and pollution on the 238U, 232Th, 222Rn and 220Rn concentrations in various natural honey samples using nuclear track detectors: impact on the adult consumers

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Mortassim, A.

    2009-01-01

    238 U and 232 Th concentrations as well as 222 Rn and 220 Rn α-activities per unit volume were measured in various natural honey samples collected from different regions in Morocco using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). These radionuclides were also measured in soils, plant flowers and nectar solutions corresponding to the honey samples studied. In addition, these radionuclides were measured in different imported honey samples. The measured 238 U, 232 Th, 222 Rn and 220 Rn concentrations ranged from (1.5 ± 0.1) mBq kg -1 to (10.6 ± 0.6) mBq kg -1 , (1.1 ± 0.1) mBq kg -1 to (4.2 ± 0.2) mBq kg -1 , (1.5 ± 0.1) Bq kg -1 to (10.6 ± 0.6) Bq kg -1 and (1.1 ± 0.1) Bq kg -1 to (4.2 ± 0.2) Bq kg -1 for the honey samples studied, respectively. Annual 238 U, 232 Th and 222 Rn intakes by Moroccan adults from the consumption of honey were assessed. The influence of the nature of soil and plant on the 238 U and 232 Th contents of the studied honey samples was investigated. These measurements were completed by an investigation of the 238 U and 232 Th transfer between soils and plant flowers and that between plant flowers and honey, and also by the investigation of the influence of pollution due to different material dusts on 238 U, 232 Th and 222 Rn in the honey samples studied. Committed equivalent doses due to the annual intake of 238 U, 232 Th and 222 Rn were evaluated in the organs of adult members of the Moroccan rural population from the ingestion of the honey samples. The maximum total committed effective dose due to 238 U, 232 Th and 222 Rn from the ingestion of natural honey by the Moroccan rural population was found to be equal to 0.64 μSνy -1 . (author)

  16. Continual monitoring of radon decay products concentration in indoor and outdoor air

    International Nuclear Information System (INIS)

    Petruf, P.; Holy, K.; Stanys, T.

    1998-01-01

    The goal of this work was the development of the method and construction and testing of measurement device for continual monitoring of radon daughters concentrations in the indoor and outdoor environment with regard to make possible to determine very low activities in the outdoor air (below % Bq/m 3 ). In this method air sample is drawn through the appropriate filter material. Radon and thoron daughters both attached and unattached on aerosols particles are collected on the filter surface and then the filter activity is counted. The silicon surface barrier detector with the active area of 200 mm 2 in monitor was used. The Millipore AW19-type filter was chosen and sampling rate of 30 l/min for collecting of the air samples. The determination of the individual activity concentrations in three-count method is based on the solution of the simultaneous equations describing the number of atoms of measured nuclides on the filter during and after sampling. The monitor was tested in three different environments (the average values of the activity concentrations of radon and its decay products in Bq/m 3 are given): in the basement of the building: 61.4 ± 5.0 of 222 Rn, 29.5 ± 2.8 of 218 Po, 14.1 ± 1.8 of 214 Pb and 12.1 ± 1.6 of 214 Bi; in the room on the second floor of the same building:22.2 ± 7.9 of 222 Rn, 7.3 ± 2.8 of 218 Po, 4.6 ± 1.9 of 214 Pb and 2.6 ± 1.2 of 214 Bi ; in the outdoor air in front of the building: 4.1 ± 2.7 of 222 Rn, 2.3 ± 0.9 of 218 Po, 1.5 ± 0.8 of 214 Pb and 1.4 ± 0.6 of 214 Bi. The results show a good agreement with expectations of the activity concentrations in three different environments. The monitor enables to determine low activity concentrations in the outdoor with an acceptable precision during one hour counting. The monitor can be used for the research of the correlation between the atmospheric stability and activity concentrations of radon decay products

  17. The atmospheric chemistry of Po-218: Technical report for the period March 1, 1987 to August 31, 1987

    International Nuclear Information System (INIS)

    Hopke, P.K.

    1987-01-01

    The chemical and physical properties of 218 Po immediately following its formation from 222 Rn decay are important in determining its behavior in indoor atmospheres and plays a major part in determining its potential health effects. In 88% of the decays, a singly charged, positive ion of 218 Po is obtained at the end of its recoil path. The modes of neutralization, small ion recombination, electron transfer, and electron scavenging are reviewed. In typical indoor air, the ion will be rapidly neutralized by transfer of electrons from lower ionization potential gases such as NO 2 . The neutral molecule can then become incorporated in ultrafine particles formed by the radiolytic processes in the recoil path. The evidence for these particles is presented

  18. Submarine groundwater discharge in a subsiding coastal lowland: A {sup 226}Ra and {sup 222}Rn investigation in the Southern Venice lagoon

    Energy Technology Data Exchange (ETDEWEB)

    Gattacceca, Julie C., E-mail: jcg54@esc.cam.ac.uk [CEREGE, Aix-Marseille Universite, UMR 6635 CNRS-IRD-CDF, Europole Mediterraneen de l' Arbois, BP80, 13545 Aix en Provence (France); Mayer, Adriano [IDPA-CNR, Via Mario Bianco 9, 20131 Milano (Italy); Cucco, Andrea [Coastal Oceanography, CNR-IAMC, Oristano Unit, Loc. Sa MArdini, 09072 Oristano (Italy); Claude, Christelle; Radakovitch, Olivier; Vallet-Coulomb, Christine; Hamelin, Bruno [CEREGE, Aix-Marseille Universite, UMR 6635 CNRS-IRD-CDF, Europole Mediterraneen de l' Arbois, BP80, 13545 Aix en Provence (France)

    2011-05-15

    Highlights: > Occurence/magnitude of submarine groundwater discharge investigated in Venice lagoon (Italy) using {sup 226}Ra and {sup 222}Rn isotopic tracers. > Single box mass balance compared with multi boxes mass balance coupled with hydrodynamic model. > Groundwater flux accounts for 1% of lagoon hydrological balance (1-3 times surface runoff) and 30-50% of tracers inputs. > Necessary to assess this flux impact on nutrient budget in lagoon. - Abstract: Several recent studies have suggested that submarine groundwater discharge (SGD) occurs in the Venice lagoon with discharge rates on the same order or larger than the surface runoff, as demonstrated previously in several other coastal zones around the world. Here, the first set of {sup 222}Rn data, along with new {sup 226}Ra data are reported, in order to investigate the occurrence and magnitude of SGD specifically in the southern basin of the lagoon. The independent connection with the Adriatic Sea (at the Chioggia inlet), in addition to the relative isolation of the water body from the main lagoon, make this area an interesting case study. There is probably only minimal fresh groundwater flux to the lagoon because the surrounding aquifer is subsiding and mainly has a lower hydraulic head than seawater. The data show that the Ra and Rn activities are in slight excess in the lagoon compared to the open sea, with values on the same order as those observed in the northern and central basins. Taking into account the water exchange rate between the lagoon and adjacent seawater provided by previous hydrodynamic numerical modelling, it is shown that this excess cannot be supported at steady state by only riverine input and by diffusive release from the sediment interstitial water. High activities observed in groundwater samples collected from 16 piezometers tapping into the shallow aquifer over the coastal lowland substantiate that the excess radioactivity in the lagoon may indeed be due to the advection of groundwater

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

    Science.gov (United States)

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

    2004-01-01

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

  20. SOIL 222Rn CONCENTRATION, CO2 AND CH4 FLUX MEASUREMENTS AROUND THE JWALAMUKHI AREA OF NORTH-WEST HIMALAYAS, INDIA.

    Science.gov (United States)

    Kumar, Arvind; Walia, Vivek; Yang, Tsanyao Frank; Fu, Ching-Chou; Singh, Surinder; Bajwa, Bikramjit Singh; Arora, Vishal

    2016-10-01

    Soil 222 Rn concentration, CO 2 and CH 4 flux measurements were conducted around the Jwalamukhi area of North-West Himalayas, India. During this study, around 37 soil gas points and flux measurements were taken with the aim to assure the suitability of this method in the study of fault zones. For this purpose, RAD 7 (Durridge, USA) was used to monitor radon concentrations, whereas portable diffuse flux meter (West Systems, Italy) was used for the CO 2 and CH 4 flux measurements. The recorded radon concentration varies from 6.1 to 34.5 kBq m -3 with an average value of 16.5 kBq m -3 The anomalous value of radon concentrations was recorded between Jwalamukhi thrust and Barsar thrust. The recorded average of CO 2 and CH 4 flux were 11.8 and 2.7 g m -2 day -1 , respectively. The good correlation between anomalous CO 2 flux and radon concentrations has been observed along the fault zone in the study area, suggesting that radon migration is dependent on CO 2 . © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Spatial distribution correlation of soil-gas radon (222Rn) and mercury with leveling deformation in northern margin fault zone of West Qinling, China.

    Science.gov (United States)

    Li, Chenhua; Zhang, Hui; Su, Hejun; Zhou, Huiling; Wang, Yanhong

    2017-11-01

    This study concerns measurement of 222 Rn and mercury concentrations in soil-gas in the northern margin fault zone of West Qinling, Tibet (China). Based on profiles crossing perpendicularly the different segments of the fault at six different locations, the relations between the gas measurements, fault deformation, and seismic activity in each segment of the studied fault were analyzed, determining seismic risks in the fault zone. Soil-gas data are heterogeneous, but appear relatively organized along the three segments of the fault. The detailed multidisciplinary analysis reveals complex interactions between the structural setting, uprising fluids, leveling and seismic activity in different fault segments. The results for both fault soil gas and deformation indicated relatively stronger fault activity in the Wushan segment in the middle-eastern segment of the northern margin fault zone of West Qinling and lower activity in the Zhangxian segment, whereas the fault in the Tianshui segment was relatively locked. Additionally, in the Wushan strike-slip pull-apart area, the active influence of fluid activities facilitated the occurrence of small to medium-sized seismic events, which prevented the occurrence of larger events; in contrast, in the Tianshui segment, the west Zhangxian segment, the weak fluid activities and the corresponding strain rate will probably lead to strong earthquake buildup. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2013-04-02

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

  3. Estimation of air-water gas exchange coefficient in a shallow lagoon based on 222Rn mass balance.

    Science.gov (United States)

    Cockenpot, S; Claude, C; Radakovitch, O

    2015-05-01

    The radon-222 mass balance is now commonly used to quantify water fluxes due to Submarine Groundwater Discharge (SGD) in coastal areas. One of the main loss terms of this mass balance, the radon evasion to the atmosphere, is based on empirical equations. This term is generally estimated using one among the many empirical equations describing the gas transfer velocity as a function of wind speed that have been proposed in the literature. These equations were, however, mainly obtained from areas of deep water and may be less appropriate for shallow areas. Here, we calculate the radon mass balance for a windy shallow coastal lagoon (mean depth of 6m and surface area of 1.55*10(8) m(2)) and use these data to estimate the radon loss to the atmosphere and the corresponding gas transfer velocity. We present new equations, adapted to our shallow water body, to express the gas transfer velocity as a function of wind speed at 10 m height (wind range from 2 to 12.5 m/s). When compared with those from the literature, these equations fit particularly well with the one of Kremer et al. (2003). Finally, we emphasize that some gas transfer exchange may always occur, even for conditions without wind. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Maximum permissible concentration of radon {sup 222}Rn in air; La concentration maximale admissible du radon 222 dans l'air

    Energy Technology Data Exchange (ETDEWEB)

    Hamard, J; Beau, P G; Ergas, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires, departement de la protection sanitaire, service d' hygiene atomique

    1968-09-01

    In order to verify the validity of the values proposed for the maximum permissible concentration of {sup 222}Rn in air, one can either approach the problem: - by epidemiological studies tending to determine the relation dose-effect both quantitatively and qualitatively; - or by choosing a lung model and clearance constants allowing a more accurate determination of the delivered dose and the localisation of the more severely irradiated portions of the bronchial tree. The radon MPC have been calculated using the model and the respiration constants set up by the I.C.R.P. Task Group on Lung dynamics. Two cases have been considered, i.e. when the radon daughter products behave as soluble materials and as insoluble ones. The values which have been found have been compared with those given up to now by several national and international bodies. (authors) [French] Deux voies d'approche peuvent etre empruntees pour verifier la validite des valeurs proposees pour la concentration maximale admissible du radon 222 dans l'air: - etudes epidemiologiques tendant a preciser qualitativement et quantitativement la relation dose-effet; - choix d'un modele pulmonaire et de constantes d'epuration permettant une determination plus precise de la dose delivree et la localisation des segments de l'arbre pulmonaire les plus irradies. Les auteurs ont utilise pour le calcul de la CMA du radon le modele et les constantes respiratoires proposees par le Task Group on Lungs dynamics de la C.I.P.R. On a pris en consideration le cas ou les descendants du radon se comportent comme des substances solubles et celui ou ils se comportent comme des substances insolubles. Les valeurs trouvees sont comparees a celles proposees jusqu'alors par divers organismes nationaux et internationaux. (auteurs)

  5. Coupling End-Member Mixing Analysis and Isotope Mass Balancing (222-Rn) for Differentiation of Fresh and Recirculated Submarine Groundwater Discharge Into Knysna Estuary, South Africa

    Science.gov (United States)

    Petermann, E.; Knöller, K.; Rocha, C.; Scholten, J.; Stollberg, R.; Weiß, H.; Schubert, M.

    2018-02-01

    Quantification of submarine groundwater discharge (SGD) is essential for evaluating the vulnerability of coastal water bodies to groundwater pollution and for understanding water body material cycles response due to potential discharge of nutrients, organic compounds, or heavy metals. Here we present an environmental tracer-based methodology for quantifying SGD into Knysna Estuary, South Africa. Both components of SGD, (1) fresh, terrestrial (FSGD) and (2) saline, recirculated (RSGD), were differentiated. We conducted an end-member mixing analysis for radon (222Rn) and salinity time series of estuary water over two tidal cycles to determine fractions of seawater, riverwater, FSGD, and RSGD. The mixing analysis was treated as a constrained optimization problem for finding the end-member mixing ratio that is producing the best fit to observations at every time step. Results revealed highest FSGD and RSGD fractions in the estuary during peak low tide. Over a 24 h time series, the portions of FSGD and RSGD in the estuary water were 0.2% and 0.8% near the estuary mouth and the FSGD/RSGD ratio was 1:3.3. We determined a median FSGD of 41,000 m³ d-1 (1.4 m³ d-1 per m shoreline) and a median RSGD of 135,000 m³ d-1 (4.5 m³ d-1 per m shoreline) which suggests that SGD exceeds river discharge by a factor of 1.0-2.1. By comparison to other sources, this implies that SGD is responsible for 28-73% of total DIN fluxes into Knysna Estuary.

  6. Alpha-particle dosimetry using solid state nuclear track detectors. Application to 222Rn and its daughters

    International Nuclear Information System (INIS)

    Barillon, R.; Chambaudet, A.

    2000-01-01

    A methodology for the determination of the detection efficiency of a solid state nuclear track detector for radon and its short-lived daughters was presented. First, particular attention is paid to the α-particles having energies and angles of incidence that lead to observable tracks after an adapted chemical etching. The results are then incorporated in a mathematical model to determine the theoretical radon detection efficiency of a polymeric detector placed in a cylindrical cell. When applied to LR115 and CR39 detectors, the model reveals the influence of the position of the radon daughters inside the cell. Radon daughters tend to link up with natural atmospheric aerosols and then settle on the cell's inside wall. This model allows to determine, among other things, the cell size for which the detector response is independent of the fraction daughters plated out. (author)

  7. Quantification of submarine groundwater discharge and its short-term dynamics by linking time-variant end-member mixing analysis and isotope mass balancing (222-Rn)

    Science.gov (United States)

    Petermann, Eric; Knöller, Kay; Stollberg, Reiner; Scholten, Jan; Rocha, Carlos; Weiß, Holger; Schubert, Michael

    2017-04-01

    Submarine groundwater discharge (SGD) plays a crucial role for the water quality of coastal waters due to associated fluxes of nutrients, organic compounds and/or heavy-metals. Thus, the quantification of SGD is essential for evaluating the vulnerability of coastal water bodies with regard to groundwater pollution as well as for understanding the matter cycles of the connected water bodies. Here, we present a scientific approach for quantifying discharge of fresh groundwater (GWf) and recirculated seawater (SWrec), including its short-term temporal dynamics, into the tide-affected Knysna estuary, South Africa. For a time-variant end-member mixing analysis we conducted time-series observations of radon (222Rn) and salinity within the estuary over two tidal cycles in combination with estimates of the related end-members for seawater, river water, GWf and SWrec. The mixing analysis was treated as constrained optimization problem for finding an end-member mixing ratio that simultaneously fits the observed data for radon and salinity best for every time-step. Uncertainty of each mixing ratio was quantified by Monte Carlo simulations of the optimization procedure considering uncertainty in end-member characterization. Results reveal the highest GWf and SWrec fraction in the estuary during peak low tide with averages of 0.8 % and 1.4 %, respectively. Further, we calculated a radon mass balance that revealed a daily radon flux of 4.8 * 108 Bq into the estuary equivalent to a GWf discharge of 29.000 m3/d (9.000-59.000 m3/d for 25th-75th percentile range) and a SWrec discharge of 80.000 m3/d (45.000-130.000 m3/d for 25th-75th percentile range). The uncertainty of SGD reflects the end-member uncertainty, i.e. the spatial heterogeneity of groundwater composition. The presented approach allows the calculation of mixing ratios of multiple uncertain end-members for time-series measurements of multiple parameters. Linking these results with a tracer mass balance allows conversion

  8. Experimental study of ion-induced nucleation by radon decay

    International Nuclear Information System (INIS)

    He, F.; Hopke, P.K.

    1993-01-01

    In the environment, the presence of ions from natural radioactivity may increase the rate of new particle formation through ion-induced nucleation. A thermal diffusion cloud chamber (TDCC) has been built to experimentally study ion-induced nucleation where the ions are produced by gaseous radioactive sources. The critical supersaturation values and nucleation rates for methanol, ethanol, 1-propanol, and 1-butanol vapors on ions produced within the volume of the chamber by alpha decay of 222 Rn have been measured quantitatively at various radioactivity concentrations and supersaturations. The presence of ion tracks and the effect of an external electric field were also investigated. The alpha tracks and ion-induced nucleation formed by 222 Rn decay become visible at the critical supersaturation that is below the value needed for homogeneous nucleation. At this supersaturation, the nucleation rates increase substantially with increasing 222 Rn at low activity concentrations, but attain limiting values at higher concentrations. The experimental results indicate that the ionization by radon decay will promote ion-cluster formation and lower the free energy barriers. The formation of visible droplets is strongly dependent on the supersaturation. This study also confirms that the external electric field has a significant effect on the observed rates of nucleation

  9. Atmospheric interaction with nanosatellites from observed orbital decay

    Science.gov (United States)

    Macario-Rojas, A.; Smith, K. L.; Crisp, N. H.; Roberts, P. C. E.

    2018-06-01

    Nanosatellites have gained considerable presence in low Earth orbits wherein the atmospheric interaction with exposed surfaces plays a fundamental role in the evolution of motion. These aspects become relevant with the increasing applicability of nanosatellites to a broader range of missions objectives. This investigation sets out to determine distinctive drag coefficient development and attributes of atmospheric gas-surface interactions in nanosatellites in the common form of standard 3U CubeSats from observed orbital decay. As orbital decay can be measured with relative accuracy, and its mechanism broken down into its constituent sources, the value of drag-related coefficients can be inferred by fitting modelled orbit predictions to observed data wherein the coefficient of interest is the adjusted parameter. The analysis uses the data of ten historical missions with documented passive attitude stabilisation strategies to reduce uncertainties. Findings indicate that it is possible to estimate fitted drag coefficients in CubeSats with physical representativeness. Assessment of atomic oxygen surface coverage derived from the fitted drag coefficients is broadly consistent with theoretical trends. The proposed methodology opens the possibility to assess atmospheric interaction characteristics by using the unprecedented opportunity arising from the numerous observed orbital decay of nanosatellites.

  10. Determination of equivalent mixing height and atmospheric stability assessment

    International Nuclear Information System (INIS)

    Simon, J.; Bulko, M.; Holy, K.

    2007-01-01

    Atmospheric stability is an indicator that reflects the intensity of boundary layer mixing processes. This feature of the atmosphere is especially important since it defines dispersive atmospheric conditions and provides information on how effectively the anthropogenic pollution will be transferred to the higher levels of the atmosphere. The assessment of atmospheric dispersiveness plays a crucial role in the protection of air quality and public health in big cities. The presented paper deals with determination of atmospheric stability via so called Equivalent Mixing Height (EMH) quantity using a radioactive noble gas 222 Rn. A method of deriving a link between 222 Rn activity concentration, eddy diffusion coefficient and EMH using fluid mechanics is also outlined in this work. (authors)

  11. Proposal for the classification of closed indoor spaces according to concentration of {sup 222}Rn and the possible doses involved; Propuesta para la clasificacion de los espacios interiores cerrados por su concentracion de Rn-222 y las posibles dosis involucradas

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, Marco; Leon, Kety; Martinez, Jorge [Direccion de Servicios, Instituto Peruano de Energia Nuclear, Lima (Peru)

    2014-07-01

    Radon causes more than 50 % of total dose from natural background radiation per year. It is widely demonstrated the capacity of radon to induce lung cancer in people exposed to this radioactive gas for long periods. Radon emerges continuously from materials that constitute soils, building materials and minerals present in our natural environment, all over the world. In our country, it is necessary to get better regulations to control the exposition of people to this gas inside buildings, dwellings and facilities where people spend their time. Our country has very simple and scarce regulations on this respect. At present, national regulations about radon are adaptations of recommendations and guides published for international organizations but without national studies or statistics to give realistic support to those rules. This work propose a classification for closed spaces where people live and work in this country taking into consideration their {sup 222}Rn concentration and probable doses involved. (authors).

  12. Cuantificación de radón (222Rn en aire y dosis de radiación en baños termales del norte de México

    Directory of Open Access Journals (Sweden)

    María de Lourdes Villalba

    2015-01-01

    Full Text Available La radiación en aguas termales utilizadas como zonas recreativas puede representar un problema de salud pública. El objetivo fue cuantificar el nivel de radón (222Rn en aire y evaluar la dosis de radiación en los baños termales establecidos en San Diego de Alcalá, Chihuahua, México. Se seleccionó un espacio de esparcimiento, se cerró puerta y ventana para simular la utilización del baño termal por el público. El nivel de 222Rn en aire se detectó utilizando un instrumento AlphaGUARD (Professional Radon Monitor de la marca GENITRON. Éste se cuantificó en Bq m-3 en diferentes tiempos 10, 20, 30, 40, 50 y 60 min, se realizaron tres mediciones; la primera en la epoca de invierno 2014 (enero y dos en la epoca de primavera de 2015 (mayo y junio. El análisis estadístico fue mediante una regresión para cada medición. Se estimó la Dosis Promedio Anual (DPA efectiva de inhalación de radón a la que se encuentran expuestas las personas que acuden a los baños termales dependiendo del número de visitas y tiempo de permanencia, el rango varió de 0.0005±4x10-4 mSv cuando se visitan los baños 12 veces al año con un permanencia de 10 minutos, hasta 0.0352±1.1x10-2 mSv visitando una vez a la semana por un periodo de 60 minutos. |

  13. Assessment of uncertainty associated with measuring exposure to radon and decay products in the French uranium miners cohort

    International Nuclear Information System (INIS)

    Allodji, Rodrigue S; Leuraud, Klervi; Laurier, Dominique; Bernhard, Sylvain; Henry, Stéphane; Bénichou, Jacques

    2012-01-01

    The reliability of exposure data directly affects the reliability of the risk estimates derived from epidemiological studies. Measurement uncertainty must be known and understood before it can be corrected. The literature on occupational exposure to radon ( 222 Rn) and its decay products reveals only a few epidemiological studies in which uncertainty has been accounted for explicitly. This work examined the sources, nature, distribution and magnitude of uncertainty of the exposure of French uranium miners to radon ( 222 Rn) and its decay products. We estimated the total size of uncertainty for this exposure with the root sum square (RSS) method, which may be an alternative when repeated measures are not available. As a result, we identified six main sources of uncertainty. The total size of the uncertainty decreased from about 47% in the period 1956–1974 to 10% after 1982, illustrating the improvement in the radiological monitoring system over time.

  14. Mitigation of radon and thoron decay products by filtration

    International Nuclear Information System (INIS)

    Wang Jin; Meisenberg, Oliver; Chen Yongheng; Karg, Erwin; Tschiersch, Jochen

    2011-01-01

    Inhalation of indoor radon ( 222 Rn) and thoron ( 220 Rn) decay products is the most important source of exposure to ionizing radiation for the human respiratory tract. Decreasing ventilation rates due to energy saving reasons in new buildings suggest additional active mitigation techniques to reduce the exposure in homes with high radon and thoron concentrations but poor ventilation. Filtration techniques with HEPA filters and simple surgical mask material have been tested for their potential to reduce the indoor exposure in terms of the total effective dose for mixed radon and thoron indoor atmospheres. The tests were performed inside an experimental room providing stable conditions. Filtration (at filtration rates of 0.2 h -1 and larger) removes attached radon and thoron decay products effectively but indoor aerosol as well. Therefore the concentration of unattached decay products (which have a higher dose coefficient) may increase. The decrease of the attached decay product concentrations could be theoretically described by a slowly decreasing exponential process. For attached radon decay products, it exhibited a faster but weaker removal process compared to attached thoron decay products (- 70% for attached radon decay products and - 80% for attached thoron decay products at a filtration rate of 0.5 h -1 with an HEPA filter). The concentration of unattached thoron decay products increased distinctly during the filtration process (+ 300%) while that of unattached radon decay products rose only slightly though at a much higher level (+ 17%). In the theoretical description these observed differences could be attributed to the different half-lives of the nuclides. Considering both effects, reduced attached and increased unattached decay product concentrations, filtration could significantly decrease the total effective dose from thoron whereas the overall effect on radon dose is small. A permanent filtration is recommended because of the slow decrease of the

  15. Comparison of techniques active and passive in measurement of radon concentration ({sup 222}Ra) in the air; Comparacao de tecnicas ativa e passiva na medicao de concentracao de radonio ({sup 222}Rn) no ar

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Evaldo Paulo de

    2017-11-01

    The purpose of this work was to perform a study comparing radon concentration measurements between two techniques used to measure radon gas in the air: one using LEXAN polycarbonate plastic detectors and the other the continuous monitor in AlphaGUARD passive mode. The concentrations of radon gas within radon emanation chambers were measured using calibrated / traceable sources generating {sup 222}Rn through {sup 226}Ra. In calibration the 'calibration factor' or 'sensitivity' was determined for the LEXAN plastic detector. The calibration work of the dosimeters was carried out at the Radon Laboratory of the Environmental Analysis Division - DIRAD IRD/CNEN and at the Natural Radioactivity Laboratory (LRN) of the Center for the Development of Nuclear Technology (CDTN/CNEN). The 'calibration factor' or 'sensitivity' was found to be 32.34 (traits.cm{sup -2})/(kBq.d.m{sup -3}). This factor was used to determine the radon concentration measured by the LEXAN plastic detectors. Also in the calibration, the efficiencies for LEXAN (94.1% ± 9.7%) and AlphaGUARD (92.5% ± 7.2%) were determined. The statistical analysis used showed good parity in the results of the measurements. It was concluded that the results were satisfactory and will serve as a good reference for studies related to the radon air meters used in this work. (author)

  16. Simulation of Rn-222 decay products concentration deposited on a filter. Description of radon1.pas computer program

    International Nuclear Information System (INIS)

    Machaj, B.

    1996-01-01

    A computer program allowing simulation of activity distribution of 222 Rn short lived decay products deposited on a filter against time is presented, for any radiation equilibrium degree of the decay products. Deposition of the decay products is simulated by summing discrete samples every 1/10 min in the sampling time from 1 to 10 min. The concentration (activity) of the decay products is computed in one minute intervals in the range 1 - 100 min. The alpha concentration and the total activity of 218 Po + 214 Po produced are computed in the range 1 to 100 min as well. (author). 10 refs, 4 figs

  17. Propose of a model for dose and hazard calculation due the Rn-222, Rn-220 and its short half-life daugthers inhalation

    International Nuclear Information System (INIS)

    Mauricio, C.L.P.

    1982-01-01

    The compartimental dosimetric model is used to simulate, by computer, the interactions of the inhalated radon atom radiations and its short half-life daugthers with cells. The metabolic trajectory of these radionuclides is described by differential equations of continuous medium dynamics, where the elements transform by radioactive decay. This work permits to determine the individual retenction function, beeing useful in radioprotection routines or emergence situations. The results of internal dosimetry are consistent with the new I.C.R.P. - 32 international recommendations. (L.C.) [pt

  18. The measurement of 222Rn and its relationship to environmental variables: Factors controlling indoor radon: Final report for the contract period June 1, 1982 to May 31, 1985

    International Nuclear Information System (INIS)

    Harley, N.H.

    1985-01-01

    Indoor levels of radon-222 and daughter nuclei were monitored at various locations within a single family dwelling and in an apartment building. Indoor levels were correlated with soil temperature, atmospheric pressure, wind, rain and time of year. 9 refs., 23 figs., 19 tabs

  19. The distribution of 210Pb in human bone and its impact on methods for the retrospective estimation of 222Rn exposure from in vivo measurements.

    Science.gov (United States)

    Johnston, Peter N; Hult, Mikael; Gasparro, Joël; Martínez-Canet, María-José; Vasselli, Roberto; McKenzie, Raymond J; Solomon, Steven B; Lambrichts, Ivo

    2005-01-01

    It is possible to estimate radon exposure to man retrospectively by the in vivo measurement of the decay product (210)Pb, which accumulates in the bones. For in vivo methods, knowledge of the distribution of (210)Pb in the skeleton is needed to determine the optimal site for measurement, the skull or the knee. In this study the activity of (210)Pb in a variety of bone samples from 3 individuals have been measured in vitro using underground gamma-ray spectrometry. The individuals were unlikely to have had elevated intakes of Rn. These measurements give baseline data on the bone massic activity of (210)Pb. They show that the massic activity is similar for each of these people and there are similar massic activities of (210)Pb in the skull and the knee of the 2 individuals for which the skull was measured. Additionally for 2 of the individuals trabecular and cortical bone were separated and massic activities were found to be strongly correlated indicating that the (210)Pb is associated with the hydroxyapatite.

  20. The distribution of 210Pb in human bone and its impact on methods for the retrospective estimation of 222Rn exposure from in vivo measurements

    International Nuclear Information System (INIS)

    Johnston, Peter N.; Hult, Mikael; Gasparro, Jogl; Martinez-Canet, Maria-Jose; Vasselli, Roberto; McKenzie, Raymond J.; Solomon, Steven B.; Lambrichts, Ivo

    2005-01-01

    It is possible to estimate radon exposure to man retrospectively by the in vivo measurement of the decay product 210 Pb, which accumulates in the bones. For in vivo methods, knowledge of the distribution of 210 Pb in the skeleton is needed to determine the optimal site for measurement, the skull or the knee. In this study the activity of 210 Pb in a variety of bone samples from 3 individuals have been measured in vitro using underground γ-ray spectrometry. The individuals were unlikely to have had elevated intakes of Rn. These measurements give baseline data on the bone massic activity of 210 Pb. They show that the massic activity is similar for each of these people and there are similar massic activities of 210 Pb in the skull and the knee of the 2 individuals for which the skull was measured. Additionally for 2 of the individuals trabecular and cortical bone were separated and massic activities were found to be strongly correlated indicating that the 210 Pb is associated with the hydroxyapatite

  1. The distribution of {sup 210}Pb in human bone and its impact on methods for the retrospective estimation of {sup 222}Rn exposure from in vivo measurements

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Peter N. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Department of Applied Physics, Royal Melbourne Institute of Technology, GPO Box 2476V, Melbourne 3001 (Australia); Hult, Mikael [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium)]. E-mail: mikael.hult@cec.eu.int; Gasparro, Jogl [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Martinez-Canet, Maria-Jose [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Vasselli, Roberto [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); McKenzie, Raymond J. [Department of Applied Physics, Royal Melbourne Institute of Technology, GPO Box 2476V, Melbourne 3001 (Australia); Solomon, Steven B. [Australian Radiation Protection and Nuclear Safety Agency, Lower Plenty Road, Yallambie 3085 (Australia); Lambrichts, Ivo [Department of Histology, Limburg University Centrum (LUC), Diepenbeek (Belgium)

    2005-07-01

    It is possible to estimate radon exposure to man retrospectively by the in vivo measurement of the decay product {sup 210}Pb, which accumulates in the bones. For in vivo methods, knowledge of the distribution of {sup 210}Pb in the skeleton is needed to determine the optimal site for measurement, the skull or the knee. In this study the activity of {sup 210}Pb in a variety of bone samples from 3 individuals have been measured in vitro using underground {gamma}-ray spectrometry. The individuals were unlikely to have had elevated intakes of Rn. These measurements give baseline data on the bone massic activity of {sup 210}Pb. They show that the massic activity is similar for each of these people and there are similar massic activities of {sup 210}Pb in the skull and the knee of the 2 individuals for which the skull was measured. Additionally for 2 of the individuals trabecular and cortical bone were separated and massic activities were found to be strongly correlated indicating that the {sup 210}Pb is associated with the hydroxyapatite.

  2. Daily fluctuations in radon concentration in a Cordoba factory complex; Fluctuaciones diurnas de la concentracion de {sup 222}Rn en el complejo fabril Cordoba

    Energy Technology Data Exchange (ETDEWEB)

    Germanier, A; Perez, R; Rubio, M [CEPROCOR, Cordoba (Argentina)

    1998-07-01

    Full text: This work shows the fluctuations of indoor radon concentration in some rooms placed inside a Cordoba Factory Complex. The measurements were performed by Victoreen Radon Monitor. The system was shaped to sample single radon concentration values after one hour integration. It utilizes a passive diffusion chamber and a silicon diffused junction detector. A portion of decay products will plate-out onto the detector and emit alpha particles into the depletion region of a diffused junction detector. The alpha energy is deposited in the detector in the form of ionization which generates a charge pulse. Only alpha pulses of an energy level similar Po-218 and Po-214 are detected. The study of the meteorological parameters shows that the daily fluctuations of the radon concentration respond to the transport and dispersion processes of radon gas through the air. Air temperature, wind's direction and speed are found to be fundamentals parameters in the observed time behavior. The meteorological data were obtained by a portable station (Davis Weathe Monitor II). The radon concentration present a maximum value (1850 Bq/m{sup 3}) at the night and a minimum value (150 Bq/m{sup 3}) at the day. (author)S. [Spanish] Texto completo: En este trabajo se estudian las fluctuaciones de la concentracion de radon 222 en aire 'indoor' en distintas habitaciones ubicadas dentro y fuera del predio del Complejo Fabril Cordoba (C.F.C.). Las determinaciones se realizaron con un detector pasivo Radon Monitor 05-418, marca Victoreen. El mismo consta de una camara de difusion electrostatica y de un detector de estado solido (Si) de juntura difundida. Este instrumento se configuro para obtener integraciones para cada una de las horas del dia. El principio de funcionamiento del detector se basa en el conteo de los decaimientos {alpha} del polonio 218 y polonio 214 atrapados dentro de la camara de difusion electrostatica. El build-up ocurrido dentro de esta camara es tenido en cuenta para

  3. Size distribution of natural aerosols and radioactive particles issued from radon, in marine and hardly polluted urban atmospheres

    International Nuclear Information System (INIS)

    Tymen, Georges.

    1979-03-01

    With a view to studying the natural radioactive particles produced by atttachment of 222 Rn daughters on environmental aerosol particles, the behaviours of CASELLA MK2 and ANDERSEN cascade impactors were first investigated. Their characteristic stage diameters were determined and size distributions of airborne particles were obtained in various situations. Moreover, an experimental and automatic equipment for measuring radon was devised and a method was developed in order to evaluate RaA, RaB, RaC concentrations in the free atmosphere. A degree of radioactive desequilibrium between 222 Rn and its daughters, more important than that in other locations was thus demonstrated. Furthermore, by means of various aerosol collection systems (ion tubes, diffusion batteries, cascade impactors, filters), the cumulative size distribution of natural radioactivity was established in the air, at ground level. Finally, from a theory of attachment of small radioactive ions on atmospheric particles, a tentative explanation of experimental results was made [fr

  4. Deposition of aerosols formed by HCDA due to decay heat transport in inner containment atmospheres

    International Nuclear Information System (INIS)

    Vate, J.F. van de

    1976-01-01

    Coupling of decay heat transfer by aerosol-laden inner containment atmospheres with aerosol deposition from such atmospheres leads to useful and simple models for calculation of the time dependence of the aerosol mass concentration. Special attention is given to thermophoretic deposition (dry case) and condensation followed by gravitational deposition (wet case). Attractive features of the models are: 1) coagulation can be omitted and therefore complicated and doubtful calculations on coagulation are avoided, 2) material and particle size of the aerosol are not important for the aerosol decay rate, 3) the aerosol decay rate is related to the decay heat production which is known function of time, and the relevant part of it must be assessed usually for other purposes as well. (orig.) [de

  5. Alpha spectroscopy by the Φ25 mm×0.1 mm YAlO{sub 3}:Ce scintillation detector under atmospheric conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kvasnicka, Jiri [Radiation Detection Systems, Unit 10, 186 Pulteney Street, Adelaide SA 5000 (Australia); Urban, Tomas, E-mail: tomas.urban@fjfi.cvut.cz [Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Brehova 78/7, 115 19 Prague, Czech Republic (Czech Republic); Tous, Jan; Smejkal, Jan; Blazek, Karel [Crytur Ltd, Palackeho 175, 511 01 Turnov (Czech Republic); Nikl, Martin [Institute of Physics AS CR, Cukrovarnicka 10, 162 53 Prague (Czech Republic)

    2017-06-01

    The YAlO{sub 3}:Ce scintillation crystal has excellent mechanical properties and is not affected if used in chemically aggressive environments. The detector with the diameter of Φ25.4 mm and thickness of 0.1 mm was coupled with the PMT, associated electronics and the MCA in order to study its alpha spectroscopy properties. The measured alpha spectra of the surface calibration sources of {sup 241}Am and {sup 230}Th were compared with results of a Monte Carlo simulation. The experiment and the simulation were carried out for three distances between the detector and the surface alpha source in order to assess the effect of the distance on the detected energy of alpha radiation. Finally, the detector was used for the monitoring of radon ({sup 222}Rn) decay products (radon daughters) in the air. It was concluded that the detector is suitable for the in-situ alpha spectroscopy monitoring under ambient atmospheric conditions. Nevertheless, in order to identify radionuclides and their activity from the measured alpha spectra a computer code would need to be developed. - Highlights: • Thin YAP: Ce scintillator crystal is proposed to be used for alpha spectrometry. • Experimental alpha spectra were compared with Monte Carlo simulated spectra. • The proposed detector assembly is suitable for the monitoring of radon decay products in air. • The results give a good potential for a quantitative analysis of the spectrum.

  6. 222Rn gas metrology in Latvia

    International Nuclear Information System (INIS)

    Bogucarska, T.; Lapenas, A.

    2004-01-01

    The measurements of radon gas provides in Latvia according with the State radiation monitoring program. The national standard/reference level for the protection of employees and population from exposure to radon Latvia has been accepted. The facilities for calibration of the radon gas measurement instruments and detectors have been established on basic of the Radiation Metrology and Testing Center which is the local SSDL for Baltic Region. The radon measurement instruments and detectors calibration can be performed at the 170-4000 Bq/m 3 range. (author)

  7. Atmospheric Influences on the Anomalous 2016 Antarctic Sea Ice Decay

    Science.gov (United States)

    Raphael, M. N.; Schlosser, E.; Haumann, A.

    2017-12-01

    Over the past three decades, a small but significant increase in sea ice extent (SIE) has been observed in the Antarctic. However, in 2016 there was a surprisingly early onset of the melt season. The maximum Antarctic SIE was reached in August rather than end of September, and was followed by a rapid decrease. The decline of the sea ice area (SIA) started even earlier, in July. The retreat of the ice was particularly large in November where Antarctic SIE exhibited a negative anomaly (compared to the 1981-2010 average) of almost 2 Mio. km2, which, combined with reduced Arctic SIE, led to a distinct minimum in global SIE. And, satellite observations show that from November 2016 to February 2017, the daily Antarctic SIE has been at record low levels. We use sea level pressure and geopotential height data from the ECMWF- Interim reanalysis, in conjunction with sea ice data obtained from the National Snow and Ice Data Centre (NSIDC), to investigate possible atmospheric influences on the observed phenomena. Indications are that both the onset of the melt in July and the rapid decrease in SIA and SIE in November were triggered by atmospheric flow patterns related to a positive Zonal Wave 3 index, i.e. synoptic situations leading to strong meridional flow. Additionally the Southern Annular Mode (SAM) index reached its second lowest November value since the beginning of the satellite observations. It is likely that the SIE decrease was preconditioned by SIA decrease. Positive feedback effects led to accelerated melt and consequently to the extraordinary low November SIE.

  8. Natural Radioactivity Accumulated in the Arctic from Long-range Atmospheric Transport - Observations in Canadian Monitoring Stations

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jing; Zhang, Weihua [Radiation Protection Bureau, Health Canada, 775 Brookfield Road, Ottawa K1A 1C1 (Canada)

    2014-07-01

    In the environment, the main sources of naturally occurring radionuclides come from radionuclides in the uranium decay series. Activity concentrations of uranium decay series radionuclides may vary considerably from place to place depending on the geological characteristics at the location. Their releases to the atmosphere are mainly through radon ({sup 222}Rn), a radioactive noble gas occurring naturally as an indirect decay product of uranium in soils and rocks. Due to the abundance of uranium, radon continuously emanates from continental land masses. With radon as the main source of naturally occurring radioactivity in the environment, one would think that the Arctic should be an area of low background radiation, because a considerable area of the Arctic is covered by glaciers and permafrost, and radon emanation rate has been reported to be negligible from those glacier and permafrost areas. However, available data have shown the opposite. The elevated level of naturally occurring radioactivity in the Arctic is due to natural sources outside of the Arctic, mainly through long-range atmospheric transport of radon and radon progeny. In some cases, natural radioactivity can accumulate to relatively high levels and become a health concern or a limiting factor of country food consumption. By definition, contaminants are undesirable substances which can cause harm to the environment, the biota, and humans. We can call these naturally accumulating radiological burdens to the Arctic 'natural contaminants' to distinguish them from the traditional meaning of contamination, the 'artificial contaminants' which are attributable to industrial or man-made sources. This paper reviews information available in the literature, analyses long-term atmospheric monitoring data in the Canadian high Arctic, sub-Arctic and mid-latitude sites, and provides discussion on research needed to address questions, such as how heavily the Arctic has been impacted by the

  9. Seasonal variations of aerosol residence time in the lower atmospheric boundary layer

    International Nuclear Information System (INIS)

    Ahmed, A.A.; Mohamed, A.; Ali, A.E.; Barakat, A.; Abd El-Hady, M.; El-Hussein, A.

    2004-01-01

    During a one year period, from Jan. 2002 up to Dec. 2002, approximately 130 air samples were analyzed to determine the atmospheric air activity concentrations of short- and long-lived ( 222 Rn) decay products 214 Pb and 210 Pb. The samples were taken by using a single-filter technique and γ-spectrometry was applied to determine the activity concentrations. A seasonal fluctuation in the concentration of 214 Pb and 210 Pb in surface air was observed. The activity concentrations of both radionuclides were observed to be relatively higher during the winter/autumn season than in spring/summer season. The mean activity concentration of 214 Pb and 210 Pb within the whole year was found to be 1.4±0.27 Bq m -3 and 1.2±0.15 mBq m -3 , respectively. Different 210 Pb: 214 Pb activity ratios during the year varied between 1.78x10 -4 and 1.6x10 -3 with a mean value of 8.9x10 -4 ±7.6x10 -5 . From the ratio between the activity concentrations of the radon decay products 214 Pb and 210 Pb a mean residence time (MRT) of aerosol particles in the atmosphere of about 10.5±0.91 d could be estimated. The seasonal variation pattern shows relatively higher values of MRT in spring/summer season than in winter/autumn season. The MRT data together with relative humidity (RH), air temperature (T) and wind speed (WS), were used for a comprehensive regression analysis of its seasonal variation in the atmospheric air

  10. Trace gas concentrations, intertropical convergence, atmospheric fronts, and ocean currents in the tropical Pacific m(Paper 8C1060)

    International Nuclear Information System (INIS)

    Wilkniss, P.E.; Rodgers, E.B.; Swinnerton, J.W.; Larson, R.E.; Lamontagne, R.A.

    1979-01-01

    Shipboard measurements of atmospheric 222 Rn, CO, and CH 4 and of dissolved CO in surface waters have been carried out in the equatorial Pacific on a cruise from Ecuador to Hawaii, Tahiti and Panama in March and April of 1974, and during transit from Los Angeles to Antarctica in November and December of 1972. The trace gas results, combined with conventional meteorological data and with satellite images from Nimbus 5 and the defense meteorological satellite project (DMSP), have provided descriptions of the intertropical convergence zones (ITCZ) near 04 0 N, 102 0 W and 03 0 N, 154 0 W in March of 1974, near 04 0 N, 86 0 W in April of 1974, and near 05 0 N, 139 0 W in November of 1972. In all cases the ITCZ seems to be located north of the south equatorial current (SEC) as shown by dissolved CO peaks in surface waters. In April of 1974 a 'second' ITCZ was observed near 01 0 S, 102 0 W just south of the SEC. A stationary front near Hawaii (20 0 N, 147 0 W) in March of 1974 was investigated. The ITCZ was marked by light shifting winds near a zone of heavy cloud cover and precipitation. In the eastern Tropical Pacific atmospheric 222 Rn increases distinctly north of the ITCZ and thus serves as an indicator for the ITCZ. CO and CH 4 do not always increase coincident with atmospheric 222 Rn. The atmospheric features of the stationary front near Hawaii are in many ways similar to those observed for the ITCZ. The front is marked by cloud cover, precipitation zone and light shifting winds. 222 Rn, CO and CH 4 increase signifantly behind the front in subsiding air which was traced back to the Asian continent. The variation of atmospheric 222 Rn, CO and CH 4 with time and geographical area over the equatorial Pacific seems to be a consequence of seasonal variations of the trade wind field and long range transport to the central Pacific from Asia and to the eastern equatorial Pacific from North and Central America

  11. Diurnal and seasonal variations of concentration and size distribution of nano aerosols (10-1100 nm) enclosing radon decay products in the Postojna Cave, Slovenia

    International Nuclear Information System (INIS)

    Bezek, M.; Gregoric, A.; Kavasi, N.; Vaupotic, J.

    2012-01-01

    At the lowest point along the tourist route in the Postojna Cave, the activity concentration of radon ( 222 Rn) short-lived decay products and number concentration and size distribution of background aerosol particles in the size range of 10-1100 nm were measured. In the warm yearly season, aerosol concentration was low (52 cm -3 ) with 21 % particles smaller than 50 nm, while in the cold season, it was higher (1238 cm -3 ) with 8 % of -3 , and fractions of unattached radon decay products were 0.62 and 0.13, respectively. (authors)

  12. Diurnal and seasonal variations of concentration and size distribution of nano aerosols (10-1100 nm) enclosing radon decay products in the Postojna Cave, Slovenia.

    Science.gov (United States)

    Bezek, M; Gregoric, A; Kávási, N; Vaupotic, J

    2012-11-01

    At the lowest point along the tourist route in the Postojna Cave, the activity concentration of radon ((222)Rn) short-lived decay products and number concentration and size distribution of background aerosol particles in the size range of 10-1100 nm were measured. In the warm yearly season, aerosol concentration was low (52 cm(-3)) with 21 % particles smaller than 50 nm, while in the cold season, it was higher (1238 cm(-3)) with 8 % of <50 nm particles. Radon activity concentrations were 4489 and 1108 Bq m(-3), and fractions of unattached radon decay products were 0.62 and 0.13, respectively.

  13. Measurement of Radon-Induced Backgrounds in the NEXT Double Beta Decay Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Novella, P.; et al.

    2018-04-02

    The measurement of the internal 222Rn activity in the NEXT-White detector during the so-called Run-II period with 136Xe-depleted xenon is discussed in detail, together with its implications for double beta decay searches in NEXT. The activity is measured through the alpha production rate induced in the fiducial volume by 222Rn and its alpha-emitting progeny. The specific activity is measured to be $(37.5\\pm 2.3~\\mathrm{(stat.)}\\pm 5.9~\\mathrm{(syst.)})$~mBq/m$^3$. Radon-induced electrons have also been characterized from the decay of the 214Bi daughter ions plating out on the cathode of the time projection chamber. From our studies, we conclude that radon-induced backgrounds are sufficiently low to enable a successful NEXT-100 physics program, as the projected rate contribution should not exceed 0.2~counts/yr in the neutrinoless double beta decay sample.

  14. Critical assessment of the deposition based dosimetric technique for radon/thoron decay products

    International Nuclear Information System (INIS)

    Mayya, Y.S.

    2010-01-01

    Inhalation doses due to radon ( 222 Rn) and thoron ( 220 Rn) are predominantly contributed by their decay products and not due to the gases themselves. Decay product measurements are being carried out essentially by either short-term active measurement like by air-sampling on a substrate followed by alpha or beta counting or by continuous active monitoring techniques based on silicon barrier detector. However, due to non-availability of satisfactory passive measurement techniques for the progeny species, it has been a usual practice to estimate the long time averaged progeny concentration from measured gas concentration using an assumed equilibrium factor. To be accurate, one is required to measure the equilibrium factor in situ along with the gas concentration. This being not practical, the assigned equilibrium factor (0.4 for indoor and 0.8 for outdoor for 222 Rn) approach has been an inevitable, though uncertain, part of the dosimetric strategies in both occupational and public domains. Further, in the case of thoron decay products however, equilibrium factor is of far more questionable validity. Thus, there is a need to shift from gas based dosimetric paradigm to that based on direct detection of progeny species

  15. Study of atmospheric neutrino interactions and search for nucleon decay in Soudan 2

    Energy Technology Data Exchange (ETDEWEB)

    Leeson, William R. [Tufts Univ., Medford, MA (United States)

    1995-12-14

    Contained event samples, including 30 single-track muon-like events, 35 single-shower electron-like events, and 34 multiprong events, have been obtained from a 1.0 kiloton-year exposure of the Soudan 2 detector. A sample of 15 multiprong events which are partially contained has also been isolated. Properties of these events are used to examine the verity of the atmospheric neutrino flavor ratio anomaly as reported by the Kamiokande and IMB-3 water Cherenkov experiments. The compatibility of the Soudan data with each of two `new physics` explanations for the anomaly, namely proton decay and neutrino oscillations, is investigated. We examine background processes which have not been explicitly treated by the water Cherenkov detectors. Chapters discuss underground non-accelerator particle physics, the atmospheric neutrino anomaly and its interpretation, the Soudan 2 detector and event selection, reconstruction of neutrino events, rock event contamination in Soudan `quasi-elastic` samples, contained multiprong events in Soudan 2, neutrino flavor composition of the multiprong sample, partially contained events in Soudan 2, nucleon decay in Soudan 2, and a summary and discussion.

  16. Study of atmospheric neutrino interactions and search for nucleon decay in Soudan 2

    International Nuclear Information System (INIS)

    Leeson, W.R.

    1995-01-01

    Contained event samples, including 30 single-track muon-like events, 35 single-shower electron-like events, and 34 multiprong events, have been obtained from a 1.0 kiloton-year exposure of the Soudan 2 detector. A sample of 15 multiprong events which are partially contained has also been isolated. Properties of these events are used to examine the verity of the atmospheric neutrino flavor ratio anomaly as reported by the Kamiokande and IMB-3 water Cherenkov experiments. The compatibility of the Soudan data with each of two 'new physics' explanations for the anomaly, namely proton decay and neutrino oscillations, is investigated. We examine background processes which have not been explicitly treated by the water Cherenkov detectors. Chapters discuss underground non-accelerator particle physics, the atmospheric neutrino anomaly and its interpretation, the Soudan 2 detector and event selection, reconstruction of neutrino events, rock event contamination in Soudan 'quasi-elastic' samples, contained multiprong events in Soudan 2, neutrino flavor composition of the multiprong sample, partially contained events in Soudan 2, nucleon decay in Soudan 2, and a summary and discussion. 12 refs., 124 figs., 28 tabs., 7 appendices

  17. Computations of concentration of radon and its decay products against time. Computer program; Obliczanie koncentracji radonu i jego produktow rozpadu w funkcji czasu. Program komputerowy

    Energy Technology Data Exchange (ETDEWEB)

    Machaj, B. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1996-12-31

    This research is aimed to develop a device for continuous monitoring of radon in the air, by measuring alpha activity of radon and its short lived decay products. The influence of alpha activity variation of radon and its daughters on the measured results is of importance and requires a knowledge of this variation with time. Employing the measurement of alpha radiation of radon and of its short lived decay products, require knowledge of radon concentration variation and its decay products against the time. A computer program in Turbo Pascal language was therefore developed performing the computations employing the known relations involved, the program being adapted for IBM PC computers. The presented program enables computation of activity of {sup 222}Rn and its daughter products: {sup 218}Po, {sup 214}Pb, {sup 214}Bi and {sup 214}Po every 1 min within the period of 0-255 min for any state of radiation equilibrium between the radon and its daughter products. The program permits also to compute alpha activity of {sup 222}Rn + {sup 218}Po + {sup 214}Po against time and the total alpha activity at selected interval of time. The results of computations are stored on the computer hard disk in ASCII format and are used a graphic program e.g. by DrawPerfect program to make diagrams. Equations employed for computation of the alpha activity of radon and its decay products as well as the description of program functions are given. (author). 2 refs, 4 figs.

  18. Two new methods of determining radon diffusion in fish otoliths

    International Nuclear Information System (INIS)

    Whitehead, N.E.; Ditchburn, R.G.

    1995-01-01

    Otoliths are bony structures found in the ears of fish and used in the 210 Pb/ 226 Ra dating method for age determination. This paper checks the assumption that 222 Rn is not lost from or added to orange roughy fish otoliths by diffusion, which would invalidate the technique. The first method of monitoring diffusion relies on measuring the gamma activity of daughter radionuclides. Otoliths were exposed to an atmosphere enriched in 222 Rn for 10 days, and the supported gamma activity inside them measured allowing for various decay corrections. The calculated radon addition was (0.5 ±0.5)% of the activity of the 226 Ra present. The second method used an alpha spectrometer and attempted to detect 222 Rn directly outguessed from otoliths in the detector vacuum chamber. The results were consistent within errors with those of the first method and showed no loss or gain of 222 Rn, supporting previous estimates of a long life-span for the orange rough y. In contrast it was found that approximately 10% of 222 Rn formed in orange roughy fish scales was lost to an evacuated environment, (hence perhaps to an aqueous environment) and that for this species it could be difficult to base a dating method on analysis of scales. Nevertheless a preliminary minimum age of 57 years was obtained. The methods could be used with non-biological samples to determine 222 Rn diffusion rates. (author). 17 refs., 5 figs

  19. Survey of some natural decay-series isotopes in the Wairakei geothermal area and possible residence-time applications

    International Nuclear Information System (INIS)

    Stewart, M.K.; Burnett, W.C.; Whitehead, N.E.

    1993-01-01

    Concentrations of selected isotopes in the uranium decay series were determined for samples collected from the Wairakei, Broadlands/Ohaaki and Waiotapu areas. /sup 226/Ra concentrations were found to be low (0.05-0.22 dpm/l), similar to values reported in neutral hot springs at Tatun geothermal area, Taiwan, but lower than other geothermal systems (Yellowstone, USA, and Latera, Central Italy) (up to 25 dpm/l). The potential of /sup 226/Ra//sup 228/Ra ratios for indicating water residence times could not be explored because /sup 228/Ra data was not available. /sup 222/Rn concentrations are higher and related to steam fractions and CO/sub 2/ concentrations. The short half-life (3.8 days) makes /sup 222/Rn suitable for estimating residence times of radon in steam, and therefore the distance of travel of steam from its source (e.g., wells WK9 and 52). /sup 210/Pb and /sup 210/Po concentrations were very low and less than detection limits in many of the Wairakei waters; no residence time applications are apparent for these isotopes. (author). 11 refs.; 5 figs.; 3 tabs

  20. A specific and correlative study of natural atmospheric radioactivity, condensation nuclei and some electrical parameters in marine or urban sites

    International Nuclear Information System (INIS)

    Le Gac, Jacqueline.

    1980-02-01

    In order to determine the correlations between the following atmospheric parameters: radon and condensation nuclei concentrations, total conductivity and space charge, we analysed their behavior over a long period, in connection with meteorological data. We simulaneously studied the equilibrium state between 222 Rn and its short-lived daughters pointing out a radioactive desequilibrium as a function of the meteorological conditions. Simultaneously, we established average experimental curves of cumulated particle size distributions of natural radioactivity in the air, differentiating urban and marine influences. Finally, a comparison between the various parameters showed that the total conductivity greatly depends on condensation nuclei and radon concentrations in the air [fr

  1. The Use of Biomonitors to Monitor Atmospheric Deposition of 210Pb

    International Nuclear Information System (INIS)

    Jeran, Z.; Jacimovic, R.

    1998-01-01

    The main source of 210 Pb in the environment is the exhalation of 222 Rn gas from the ground to the atmosphere during the radioactive decay of natural uranium - radium chain. In the atmosphere this radionuclide is rapidly attached to small particles - aerosols, predominantly on those particles below 0.3 mm. The half-life of 210 Pb is longer than the atmospheric residence time of the aerosols on which it resides (1). By sedimentation and washout of aerosols this nuclide is then transferred to the soil or vegetation. The other main sources include burning of fossil fuels and phosphate fertilizers. The usual way to determine the levels of 210 Pb and other radionuclides in the atmosphere is the use of a high volume filter system, which should operate for a long time to collect enough material for analysis. An other approach to determining the outdoor levels of radionuclides is the use of suitable biomonitors such as lichens or mosses. These organisms, although neither evolutionarie nor taxonomically related, have some common characteristics which enable them to be used as monitors for atmospheric pollution. They lack roots and protective organs against the substances derived from the atmosphere (stomata and cuticle) and are very efficient accumulators of atmospheric particulate material and chemical substances such as radionuclides or heavy metals (2). The levels of these substances in lichens and mosses are usually much higher than in air particulates or precipitation and for these reason the analysis is much easier. Another advantage of biomonitors over conventional sampling of air particulates or precipitation is that the collection of lichens or mosses is very cheap therefore allows a very large number of sites to be included in the same survey and permits detailed geographical deposition patterns to be drawn (3). It must be emphasised that concentration data on elements or radionuclides in lichens or mosses represent the relative deposition patterns over a certain

  2. Evaluation of groundwater discharge into small lakes based on the temporal distribution of radon-222

    Science.gov (United States)

    Dimova, N.T.; Burnett, W.C.

    2011-01-01

    In order to evaluate groundwater discharge into small lakes we constructed a model that is based on the budget of 222Rn (radon t1/2 5 3.8 d) as a tracer. The main assumptions in our model are that the lake's waters are wellmixed horizontally and vertically; the only significant 222Rn source is via groundwater discharge; and the only losses are due to decay and atmospheric evasion. In order to evaluate the groundwater-derived 222Rn flux, we monitored the 222Rn concentration in lake water over periods long enough (usually 1-3 d) to observe changes likely caused by variations in atmospheric exchange (primarily a function of wind speed and temperature). We then attempt to reproduce the observed record by accounting for decay and atmospheric losses and by estimating the total 222Rn input flux using an iterative approach. Our methodology was tested in two lakes in central Florida: one of which is thought to have significant groundwater inputs (Lake Haines) and another that is known not to have any groundwater inflows but requires daily groundwater augmentation from a deep aquifer (Round Lake). Model results were consistent with independent seepage meter data at both Lake Haines (positive seepage of ??? 1.6 ?? 104 m3 d-1 in Mar 2008) and at Round Lake (no net groundwater seepage). ?? 2011, by the American Society of Limnology and Oceanography, Inc.

  3. Review of investigations of atmospheric contamination carried out in the USSR from 1975 to 1978

    International Nuclear Information System (INIS)

    Styro, B.I.

    1980-01-01

    A brief characteristic of main directions of atmospherical contamination is given. A bibliographic list of articles and books, published in the USSR during 1975-1978 is presented. Atmospherical contamination study was carried out within the wide range of problems during this period. They are: both artificial and natural radioactive substances, the behaviour of these substances in the atmosphere and their application as tracers for a number of processes of atmospheric physics. Attention was paid to the study of radon fission products ( 222 Rn, 210 Pb, 210 Bi, 210 Po) behaviour in the atmosphere, of the ratio between 90 Sr, 137 Cs, 144 Ce concentrations in surface air during the first months after nuclear explosion, to the study of radioactive fallout and washout of radionuclides from the atmosphere, of cosmic ray produced radionuclides, 85 Kr concentration as a product of the nuclear power production development. Serious attention was also paid to methodics problems referring measurements and sampling [ru

  4. Determination of the characteristic limits and responses of nuclear track detectors in mixed radon and thoron atmospheres

    International Nuclear Information System (INIS)

    Röttger, Annette; Honig, Anja; Schrammel, Dieter; Strauss, Heinrich F.

    2016-01-01

    Closed nuclear track detectors are widely used for the determination of Rn-222 exposures. There are also partial open systems available, which are specially designed for the determination of the exposure to Rn-220, which is a relevant exposure in special workplaces or in specific regions of the world. This paper presents data and a detail analysis of how to determine the cross-correlation by calibration in pure Rn-222 and pure Rn-220 atm. By these means calibration coefficients for the analysis of real mixed atmospheres can be obtained. The respective decision threshold, detection limit and limits of the confidence interval were determined according to ISO 11929 (ISO 11929:2010, 2010). The exposure of detectors was performed at the radon reference chamber and the thoron progeny chamber of the Physikalisch-Technische Bundesanstalt (PTB). The analysis of track response was done at Parc RGM, while the analytical routines were developed in the Leibniz University Hanover, Institute Radioökologie und Strahlenschutz IRS at the working Group AK SIGMA (Arbeitskreis Nachweisgrenzen). - Highlights: • Analysis of exposure in reference atmospheres according ISO 11929. • Calibration of nuclear track detectors for 222 Rn and 220 Rn. • Calculation of cross-correlation by calibration in pure 222 Rn and 220 Rn atmospheres. • Thoron activity concentration should not be omitted in radon exposure determinations.

  5. In-situ radionuclide transport and preferential groundwater flows at INEEL (Idaho): Decay-series disequilibrium studies

    International Nuclear Information System (INIS)

    Luo, S.; Ku, T.L.; Roback, R.; Murrell, M.; McLing, T.L.

    2000-01-01

    Uranium and thorium-decay series disequilibria in groundwater occur as a result of water-rock interactions, and they provide site-specific, natural analog information for assessment of in-situ, long-term migration of radionuclides in the far field of a nuclear waste disposal site. In this study, a mass balance model was used to relate the decay-series radionuclide distributions among solution, sorbed and solid phases in an aquifer system to processes of water transport, sorption-desorption, dissolution-precipitation, radioactive ingrowth-decay, and α recoil. Isotopes of U and Rn were measured in 23 groundwater samples collected from a basaltic aquifer at the Idaho National Engineering and Environmental Laboratory (INEEL), Idaho. The results show that groundwater activities of Th and Ra isotopes are 2--4 orders lower than those of their U progenitors. Modeling of the observed disequilibria places the following constraints on the time scale of radionuclide migration and water-rock interaction at INEEL: (1) Time for sorption is minutes for Ra and Th; time for desorption is days for Ra and years for Th; and time for precipitation is days for Th, years for Ra, and centuries for U. (2) Retardation factors due to sorption average > 10 6 for 232 Th, approximately10 4 for 226 Ra, and approximately10 3 for 238 U. (3) Dissolution rates of rocks are approximately70 to 800 mg/L/y. (4) Ages of groundwater range from 222 Rn occur near the groundwater recharging sites as well as in the major flow pathways. Decay of the sorbed parent radionuclides (e.g., 226 Ra and 228 Ra) on micro-fracture surfaces constitutes an important source of their daughter ( 222 Rn and 228 Th) activities in groundwater

  6. Outdoor radon levels and dose to the members of public residing in and around the new BARC campus, Visakhapatnam, India

    International Nuclear Information System (INIS)

    Vinod Kumar, A.; Sumesh, C.G.; Krishna, N.S.; Sahoo, S.K.; Tripathi, R.M.; Puranik, V.D.

    2010-01-01

    Natural radiation is the largest contributor to the collective radiation dose to the world population. The greatest fraction of the natural radiation exposure to humans results from inhalation of the short-lived decay products of Radon ( 222 Rn) and Thoron ( 220 Rn), which occur in the free atmosphere and in higher concentrations in the room air of buildings. 222 Rn, being the most important radon isotope in terms of radiation exposure contributes about 55% of the annual radiation dose to the general population from natural radiation sources

  7. Field experiment on 222Rn flux from reclaimed uranium tailings

    International Nuclear Information System (INIS)

    Hinton, T.G.

    1983-01-01

    Design and construction techniques are described for a 1.6 ha experimental uranium mill tailings reclamation plot. A passive, activated charcoal device was developed and tested for measurements of radon flux. Experiments on radon flux versus overburden depth showed that tailings covered with 1.5 m of revegetated or 0.3 m of bare overburden had exhalation rates comparable to background. Vegetated subplots exhibited a significantly higher (often an order of magnitude) flux than the bare subplots. Results on the variation of flux over time did not reveal any definitive patterns, possibly due to the high variability among replicates. A positive correlation was demonstrated between precipitation and radon flux. This is discussed in detail and possibly explained by the increase in water content of the micropores within the tailings, which increases the emanation coefficient without adversely effecting the diffusion coefficient of the overburden. 30 references, 7 figures, 3 tables

  8. Consistent treatment of ground deposition together with species growth and decay during atmospheric transport

    International Nuclear Information System (INIS)

    Murphy, B.D.; Nelson, C.B.; Ohr, S.Y.

    1981-01-01

    We discuss the adaptation of a trajectory model to an initial pollutant species and a series of successor species at mesoscale distances. The effect of source height is discussed since it is important in determining close-in ground level concentration, which influences plume depletion due to dry deposition. A scheme is outlined which handles deposition and species decay in a consistent manner and which does so for an arbitrary number of successor pollutant species. This scheme is discussed in terms of a Lagrangian trajectory model which accounts for initial source height and which calculates ground-level concentrations out to mesoscale distances

  9. Atmospheric stability-dependent infinite wind-farm models and the wake-decay coefficient

    DEFF Research Database (Denmark)

    Peña, Alfredo; Rathmann, Ole

    2014-01-01

    We extend the infinite wind-farm boundary-layer (IWFBL) model of Frandsen to take into account atmospheric static stability effects. This extended model is compared with the IWFBL model of Emeis and to the Park wake model used inWind Atlas Analysis and Application Program (WAsP), which is computed......) larger than the adjusted values for a wide range of neutral to stable atmospheric stability conditions, a number of roughness lengths and turbine separations lower than _ 10 rotor diameters and (ii) too large compared with those obtained by a semiempirical formulation (relating the ratio of the friction...

  10. Thoron (220Rn) in the indoor atmospheric environment

    International Nuclear Information System (INIS)

    Ramachandran, T.V.

    2006-01-01

    Naturally occurring background radiation is a topic, which has evoked curiosity and concern between the scientist and layman alike in recent years due to the shift in focus of health effects due to exposure of radiation from acute high level to chronic low level. Many locations around the world have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It has been estimated that inhalation of 222 Rn, 2 20 Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. In the Indian context, in an earlier national survey, the external gamma radiation dose rates have been more or less well mapped using thermo luminescent dosimeters covering more than 214 locations, which has yielded a national average of 775 mGy/y. Of this, nearly 48.7% contribution of the dose rate is from 40 K and the rest from the uranium (33.6%) and thorium (17.7%) series. A good database pertaining to the country wide levels of uranium, thorium and potassium in geological materials also exists. Thus, there exists a good database on the total external gamma radiation level across the country. Since the contribution from inhalation of 222 Rn, 220 Rn and their short lived progenies contributes more than 54% of the total background radiation dose, it was necessary to supplement the external component with inhalation component. This component is not adequately estimated for the country so far on national level. With this in mind, a national survey has been executed by this center involving a large number of universities and other allied research institutions from different parts of the country for the estimation of inhalation component of the dose

  11. Atmospheric stability-dependent infinite wind-farm models and the wake-decay coefficient

    OpenAIRE

    Peña, Alfredo; Rathmann, Ole

    2014-01-01

    We extend the infinite wind-farm boundary-layer (IWFBL) model of Frandsen to take into account atmospheric static stability effects. This extended model is compared with the IWFBL model of Emeis and to the Park wake model used inWind Atlas Analysis and Application Program (WAsP), which is computed for an infinite wind farm. The models show similar behavior for the wind-speed reduction when accounting for a number of surface roughness lengths, turbine to turbine separations and wind speeds und...

  12. Atmospheric concentration of 210Pb in East Asia and its contribution to Japanese islands by long-range transport

    International Nuclear Information System (INIS)

    Doi, Taeko; Sato, Shin; Sato, Jun

    2007-01-01

    Atmospheric 210 Pb is a long-lived progeny of 222 Rn generated from the earth's crust and exists as adsorbed onto the surface of aerosol particles. The distribution of atmospheric 210 Pb in East Asia reflects (1) the concentration levels in continental and maritime air masses and (2) the spatial extent of the continental air mass. This paper reviews the previously observed results on seasonal variation of 210 Pb concentration at several sites of Japan, Korea and China to evaluate the contribution of continental to Japanese atmosphere, and the specific activity of 210 Pb in the main components of aerosol samples and discusses from the view point of the Japanese islands. The authors conclude that aerosols from continental East Asia in winter contain more soil particles with low specific radioactivity of 210 Pb than the aerosols in Japan and that the natural radionuclide is extremely useful tracer for researches on meteorological phenomena and global transfer of environmental pollution. (S. Ohno)

  13. Nano size Aerosols of Radon Decay Products in Various Environments

    International Nuclear Information System (INIS)

    Vaupotic, J.

    2008-01-01

    The radioactive noble gas radon (222Rn, alpha decay, t 1/2 = 3.82 days) is always accompanied by its short-lived decay products (RnDP): 218Po (alpha decay, t 1/2 = 3.10 min), 214Pb (beta/gamma decay, t 1/2 = 26.8 min), 214Bi (beta/gamma decay, t 1/2 = 19.9 min), and 214Po (alpha decay, t 1/2 = 164 μs). In indoor and outdoor air, they appear as unattached RnDP in the form of clusters in the size range 0.5-3 nm and as attached RnDP between 200 and 800 nm. Because of plate-out of aerosols on the walls and floor of a room, as well as air movement and entry of fresh air, radioactive equilibrium between RnDP and Rn in indoor air is only partly achieved and is expressed as a fraction between 0 and 1, called the equilibrium factor, F. Birchall and James elaborated a dosimetric approach to calculate the dose conversion factor, DCF D , based on f un . In this paper, the results of our studies on fun in 29 rooms of kindergartens and 26 rooms of elementary and high schools, at the lowest point and the railway station in the Postojna Cave, and in 4 rooms in wineries in Slovenia are reported, and DCF D values based on the Porstendorfer formulae are discussed and compared with the DCF E value recommended by ICRP-65

  14. The detection and measurement of the electrical mobility size distributions associated with radon decay products

    International Nuclear Information System (INIS)

    Fei, Lin.

    1996-04-01

    The potential risk of lung cancer has evoked interest in the properties of radon decay products. There are two forms of this progeny: either attached to ambient aerosols, or still in the status of ions/molecules/small clusters. This ''unattached'' activity would give a higher dose per unit of airborne activity than the ''attached'' progeny that are rather poorly deposited. In this thesis, a system for determining unattached radon decay products electrical mobility size distribution by measuring their electrical mobilities was developed, based on the fact that about 88% of 218 Po atoms have unit charge at the end of their recoil after decay from 222 Rn, while the remainder are neutral. Essential part of the setup is the radon-aerosol chamber with the Circular Electrical Mobility Spectrometer (CEMS) inside. CEMS is used for sampling and classifying the charged radioactive clusters produced in the chamber. An alpha- sensitive plastic, CR-39 disk, is placed in CEMS as an inlaid disk electrode and the alpha particle detector. CEMS showed good performance in fine inactive particles' classification. If it also works well for radon decay products, it can offer a convenient size distribution measurement for radioactive ultrafine particles. However, the experiments did not obtain an acceptable resolution. Suggestions are made for solving this problem

  15. RETADD-II: a long-range atmospheric trajectory model with consistent treatment of deposition loss and species growth and decay

    International Nuclear Information System (INIS)

    Murphy, B.D.; Ohr, S.Y.; Begovich, C.L.

    1984-08-01

    A versatile model is described which estimates long-range atmospheric dispersion based on plume trajectories. This model allows the treatment of the dispersal from a source at an arbitrary height while taking account of plume depletion by dry and wet deposition together with the decay of material to successor species. The plume depletion, decay and growth equations are solved in an efficient manner which can accommodate up to eight pollutants (i.e., a parent and seven serial decay products). The code is particularly suitable for applications involving radioactive chain decay or for cases involving chemical species with successor decay products. Arbitrary emission rates can be specified for the members of the chain or, as is commonly the case, a sole emission rate can be specified for the first member. The code uses readily available upper-air wind data for the North American continent and it is therefore intended for the estimation of regional or continental scale dispersion patterns. This code is one of a group of codes, the Computerized Radiological Risk Investigation System (Baes and Miller, 1981), designed to simulate the transport of radionuclides through environmental pathways. 24 references, 5 figures

  16. Molecular markers reliably predict post-harvest decay of fresh-cut lettuce in modified atmosphere packaging

    Science.gov (United States)

    Fresh-cut lettuce is popular, but highly perishable product. Genetic studies of two bi-parental populations derived from crossing parents with rapid and slow rates of decay showed that the decay rate is heritable (broad spectrum heritability H2 of 0.56 – 0.87). The major genetic determinant of the d...

  17. The German thoron progeny chamber-Concept and application

    International Nuclear Information System (INIS)

    Roettger, Annette; Honig, Anja; Arnold, Dirk

    2009-01-01

    Following completion of the project 'Generation and characterisation of reference atmospheres of thoron decay products for the calibration of measuring devices for thoron decay products', the Physikalisch-Technische Bundesanstalt (PTB) now operates a thoron progeny chamber in which 220 Rn (thoron), 222 Rn and its progenies can be made available under almost all ambient conditions. This allows all measuring systems to be calibrated under realistic climatic conditions with an accuracy unique worldwide.

  18. Radon decay products and 10–1100 nm aerosol particles in Postojna Cave

    Directory of Open Access Journals (Sweden)

    M. Bezek

    2013-03-01

    Full Text Available At the lowest point along the tourist route in Postojna Cave, the activity concentration of radon (222Rn decay products and the number concentration and size distribution of aerosol particles in the size range of 10–1100 nm were monitored, with the focus on the unattached fraction (fun of radon decay products (RnDPs, a key parameter in radon dosimetry. The total number concentration of aerosols during visits in summer was lower (700 cm−3 than in winter (2800 cm−3, and was dominated by 50 nm particles (related to the attached RnDPs in winter. This explains the higher fun values in summer (0.75 and the lower winter measurement (0.04 and, consequently, DCFD values of 43.6 and 13.1 mSv WLM−1 respectively for the calculated dose conversion factors. The difference is caused by an enhanced inflow of fresh outside air, driven in winter by the higher air temperature in the cave compared to outside, resulting in the introduction of outside aerosol particles into the cave.

  19. Radon decay products and 10-1100 nm aerosol particles in Postojna Cave

    Science.gov (United States)

    Bezek, M.; Gregorič, A.; Vaupotič, J.

    2013-03-01

    At the lowest point along the tourist route in Postojna Cave, the activity concentration of radon (222Rn) decay products and the number concentration and size distribution of aerosol particles in the size range of 10-1100 nm were monitored, with the focus on the unattached fraction (fun) of radon decay products (RnDPs), a key parameter in radon dosimetry. The total number concentration of aerosols during visits in summer was lower (700 cm-3) than in winter (2800 cm-3), and was dominated by 50 nm particles (related to the attached RnDPs) in winter. This explains the higher fun values in summer (0.75) and the lower winter measurement (0.04) and, consequently, DCFD values of 43.6 and 13.1 mSv WLM-1 respectively for the calculated dose conversion factors. The difference is caused by an enhanced inflow of fresh outside air, driven in winter by the higher air temperature in the cave compared to outside, resulting in the introduction of outside aerosol particles into the cave.

  20. Inferring Groundwater Age in an Alluvial Aquifer from Tracer Concentrations in the Stream - Little Wind River, Wyoming

    Science.gov (United States)

    Goble, D.; Gardner, W. P.; Naftz, D. L.; Solder, J. E.

    2017-12-01

    We use environmental tracers: CFC's, SF6, and 222Rn measured in stream water to determine volume and mean age of groundwater discharging to the Little Wind River, near Riverton, Wyoming. Samples of 222Rn were collected every 200 m along a 2 km reach, surrounding a known groundwater discharge zone. Nearby groundwater wells, in-stream piezometers and seepage meters were sampled for 222Rn, CFC's and SF6. Tracer concentrations measured in groundwater and in-stream piezometers were used to estimate the mean age of the subsurface system. High resolution 222Rn samples were used to determine the location and volume of groundwater inflow using a model of instream transport that includes radioactive decay and gas exchange with the atmosphere. The age of groundwater entering the stream was then estimated from in-stream measured CFC and SF6 concentrations using a new coupled stream transport and lumped-parameter groundwater age model. Ages derived from in-stream measurements were then compared to the age of subsurface water measured in piezometers, seepage meters, and groundwater wells. We then asses the ability of groundwater age inferred from in-stream samples to provide constraint on the age of the subsurface discharge to the stream. The ability to asses groundwater age from in-stream samples can provide a convenient method to constrain the regional distribution of groundwater circulation rates when groundwater sampling is challenging or wells are not in place.

  1. Seasonal variations of intensity of muons and electrons of decay in points of probe measurements of cosmic radiation in the atmosphere

    International Nuclear Information System (INIS)

    Kurguzova, A.I.; Charakhch'yan, T.N.

    1983-01-01

    Altitude-dependent intensities of muon and electron decay are calculated for the summer and winter seasons in the regions of Murmansk, Moscow, Alma-Ata and Mirnyj (the Antarctica). Values of the calculated temperature coefficients of muonf and electron decay for three levels (50, 500 and 1000 g/cm 2 ) are given. Seasonal variations of the muone and electron intensities are practically the same for all the points at depths X > 300 g/cm 2 (approximately 5% for muons and approximately 1% for electrons); at depths X 2 in Mirnyj the variations are considerably higher than in other points. Seasonal variations of the cosmic ray intensity on the surface of the Earth make up approximately 4%, in the low atmosphere (X=500 g/cm 2 ) they make up approximately 2%. In Mirnyj the seasonal variations of cosmic rays in the stratosphere (X=50 g/cm 2 ) also make up approximately 2%

  2. Determination of the mean aerosol residence times in the atmosphere and additional 210Po input on the base of simultaneous determination of 7Be, 22Na, 210Pb, 210Bi and 210Po in urban air

    International Nuclear Information System (INIS)

    Magdalena Dlugosz-Lisiecka; Henryk Bem

    2012-01-01

    The significant differences in the activities of 210 Pb, 210 Bi, 210 Po and cosmogenic 7 Be and 22 Na radionuclides in the urban aerosol samples collected in the summers 2010 and 2011 in the Lodz city of Poland were observed. Simultaneous measurement of these radionuclides, after a simple modification of the one compartment model, allows us to calculate both: the corrected aerosol residence times in the troposphere (1 / 25 days) and in the lower stratosphere (103 / 205 days). The relative input of the additional sources (beside of the 222 Rn decay in the air) to the total activity concentrations of 210 Pb, 210 Bi and 210 Po radionuclides in the urban air, plays a substantial role (up to 97% of the total activity) only in the case of 210 Po. (author)

  3. Modeling the formation, decay, and partitioning of semivolatile nitro-polycyclic aromatic hydrocarbons (nitronaphthalenes) in the atmosphere

    DEFF Research Database (Denmark)

    Feilberg, A.; Kamens, R.M.; Strommen, M.R.

    1999-01-01

    A nitronaphthalene kinetics mechanism has been implemented and added to the photochemical smog mechanism, Carbon Bond-4. This mechanism was used to simulate the formation, decay, and partitioning of 1- and 2-nitronaphthalene and compare it to outdoor smog chamber data. The results suggest that th...

  4. The effects of atmospheric pollutants upon standstone: evidence from real time measurements and analysis of decay features on historic buildings

    Energy Technology Data Exchange (ETDEWEB)

    Halsey, D.P.; Dews, J.; Harris, F.C. [Wolverhampton Univ. (United Kingdom). School of Construction, Engineering and Technology; Mitchell, D.J. [Wolverhampton Univ. (United Kingdom). School of Applied Sciences

    1995-12-31

    Due to the urbanisation and industrialisation of the West Midlands, UK, historic sandstone buildings are exposed to atmospheric pollution. In order to assess the impact of this pollution upon their deterioration, chemical analysis of runoff water, from sandstone and control surfaces, has been carried out. The amount of stone affected by atmospheric pollution has been quantified by surveying selected sandstone buildings. (author)

  5. The effects of atmospheric pollutants upon standstone: evidence from real time measurements and analysis of decay features on historic buildings

    Energy Technology Data Exchange (ETDEWEB)

    Halsey, D P; Dews, J; Harris, F C [Wolverhampton Univ. (United Kingdom). School of Construction, Engineering and Technology; Mitchell, D J [Wolverhampton Univ. (United Kingdom). School of Applied Sciences

    1996-12-31

    Due to the urbanisation and industrialisation of the West Midlands, UK, historic sandstone buildings are exposed to atmospheric pollution. In order to assess the impact of this pollution upon their deterioration, chemical analysis of runoff water, from sandstone and control surfaces, has been carried out. The amount of stone affected by atmospheric pollution has been quantified by surveying selected sandstone buildings. (author)

  6. Radon progeny distribution in cylindrical diffusion chambers

    International Nuclear Information System (INIS)

    Pressyanov, Dobromir S.

    2008-01-01

    An algorithm to model the diffusion of radioactive decay chain atoms is presented. Exact mathematical solutions in cylindrical geometry are given. They are used to obtain expressions for the concentrations of 222 Rn progeny atoms in the volume and deposited on the wall surface in cylindrical diffusion chambers. The dependence of volume fractions of 222 Rn progeny and chamber sensitivity on the coefficient of diffusion of 222 Rn progeny atoms in air is modeled.

  7. Estimated risk from exposure to radon decay products in US homes

    International Nuclear Information System (INIS)

    Nero, A.V. Jr.

    1986-05-01

    Recent analyses now permit direct estimation of the risks of lung cancer from radon decay products in US homes. Analysis of data from indoor monitoring in single-family homes yields a tentative frequency distribution of annual-average 222 Rn concentrations averaging 55 Bq m -3 and having 2% of homes exceeding 300 Bq m -3 . Application of the results of occupational epidemiological studies, either directly or using recent advances in lung dosimetry, to indoor exposures suggests that the average indoor concentration entails a lifetime risk of lung cancer of 0.3% or about 10% of the total risk of lung cancer. The risk to individuals occupying the homes with 300 Bq m -3 or more for their lifetimes is estimated to exceed 2%, with risks from the homes with thousands of Bq m -3 correspondingly higher, even exceeding the total risk of premature death due to cigarette smoking. The potential for such average and high-level risks in ordinary homes forces development of a new perspective on environmental exposures

  8. Release of uranium decay-series nuclides from Florida phosphate rock

    International Nuclear Information System (INIS)

    Chin, P.A.; Deetae, S.; Burnett, W.C.

    1985-01-01

    Studies are being conducted on Florida phosphate rock to help understand the release of natural decay-series radionuclides into associated groundwaters. The authors have analyzed all isotopes with half-lives longer than a few days in samples of both weathered and unweathered phosphate rock previously separated into seven size classes. Samples which have been subjected to intense weathering display higher specific activities than relatively fresh materials with the highest activities in weathered samples occurring in the 210 Pb/ 226 Ra which is close to unity. Unweathered samples show exactly the reverse behavior. This is probably a result of 222 Rn diffusion and subsequent adsorption onto fine particles. Mass balance calculations of total activities by summation of the activities measured within each individual size class produce lower results compared to those actually measured in bulk samples of the phosphatic materials. This apparent loss may be due either to loss of very fine-grained, high-activity particles or actual solution of these radionuclides into the deionized water used during the wet seiving process

  9. Radon-induced surface contaminations in neutrinoless double beta decay and dark matter experiments

    International Nuclear Information System (INIS)

    Pattavina, L.

    2011-01-01

    In experiments looking for rare events, like neutrinoless double beta decay (DBD0ν) and dark matter search (DM), one of the main issues is to increase the experimental sensitivity through the material selection and production. The background contribution coming from the materials used for the detector realization has to be minimized. Moreover the net reduction of the background produced by the bulk part of the apparatus has raised concerns about the background contribution coming from the surfaces. Many procedures and techniques were developed during the last years in order to remove and to minimize the presence of possible contaminants on detector surfaces. To succeed in this strategy a big effort was put in defining all possible mechanisms that lead to surface contaminations, as well as specific cleaning procedures, which are able to reduce and control the surface radioactivity. The presence in air and gases of possible radioactive elements that can stick on the detector surfaces can lead to a recontamination process that will vanish all the applied cleaning procedures. Here is presented and analyzed the contribution to the background of rare events experiments like CUORE experiment (DBD0ν) and EDELWEISS experiment (DM) produced by an exposure of their detector components to a big activity of 222 Rn, radioactive daughter isotope from the 238 U chain. (author)

  10. Determination of internal exposure doses of the personnel of uranium-mining company due to radon isotopes decay products

    International Nuclear Information System (INIS)

    Sevostyanov, V.N.

    2004-01-01

    This work carries out a determination of individual doses of internal exposure of the staff of the uranium-mining company in Kazakhstan due to radon decay products. The company extracts uranium by in-situ leaching. After leaching, uranium is sorbed from a solution in facilities where the staff is located. The state of three uranium mines was analyzed. The dose determination was conducted in tune with the proposed method by using integral alpha-tracking detectors to identify the content of 222 Rn and express appliances to identify the content of radio-active aerosols in air of the working area for determination the equilibrium coefficient. The measurements were performed within one year. The work produced the results in average annual values of radon and thoron decay products activity concentration and variation, equilibrium coefficient variation, and so-called expressive-to-integral value conversion factor. The obtained personnel's individual radiation doses due to radon exposure for this period lie within the range of < 1 mSv/year. (author)

  11. A standalone decay heat removal device for the Gas-cooled Fast Reactor for intermediate to atmospheric pressure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Epiney, A., E-mail: aaron@epiney.ch [Paul Scherrer Institute PSI, Villigen (Switzerland); Ecole Polytechnique Federale EPFL, Lausanne (Switzerland); Alpy, N., E-mail: nicolas.alpy@cea.fr [CEA, DEN, Service d' Etudes des Systemes Innovants, F-13108 Saint Paul Lez Durance (France); Mikityuk, K., E-mail: konstantin.mikityuk@psi.ch [Paul Scherrer Institute PSI, Villigen (Switzerland); Chawla, R., E-mail: rakesh.chawla@psi.ch [Paul Scherrer Institute PSI, Villigen (Switzerland); Ecole Polytechnique Federale EPFL, Lausanne (Switzerland)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer An analytical model predicting Brayton cycle off-design steady states, is developed. Black-Right-Pointing-Pointer The model is used to design an autonomous decay heat removal system for the GFR. Black-Right-Pointing-Pointer Predictions of the analytical model are verified using CATHARE. Black-Right-Pointing-Pointer CATHARE code is used to simulate a set of GFR safety depressurization transients using this device. Black-Right-Pointing-Pointer Convenient turbo-machine designs exist for the targeted autonomous decay heat removal for a wide pressure range. - Abstract: This paper reports a design study for a Brayton cycle machine, which would constitute a dedicated, standalone decay heat removal (DHR) device for the Generation IV Gas-cooled Fast Reactor (GFR). In comparison to the DHR reference strategy developed by the French Commissariat a l'Energie Atomique during the GFR pre-conceptual design phase (which was completed at the end of 2007), the salient feature of this alternative device would be to combine the energetic autonomy of the natural convection process - which is foreseen for operation at high and medium pressures - with the efficiency of the forced convection process which is foreseen for operation down to very low pressures. An analytical model, the so-called 'Brayton scoping model', is described first. This is based on simplified thermodynamic and aerodynamic equations, and was developed to highlight design choices. Two different machine designs are analyzed: a Brayton loop turbo-machine working with helium, and a second one working with nitrogen, since nitrogen is the heavy gas foreseen to be injected into the primary system to enhance the natural convection under loss-of-coolant-accident (LOCA) conditions. Simulations of the steady-state and transient behavior of the proposed device have then been carried out using the CATHARE code. These serve to confirm the insights obtained from usage of the

  12. Preliminary results on soil-emitted gamma radiation and its relation with the local atmospheric electric field at Amieira (Portugal)

    International Nuclear Information System (INIS)

    Lopes, F; Barbosa, S M; Silva, H G; Bárias, S

    2015-01-01

    The atmospheric electric field near the Earth's surface is dominated by atmospheric pollutants and natural radioactivity, with the latter directly linked to radon ( 222 Rn) gas. For a better comprehension on the temporal variability of both the atmospheric electric field and the radon concentration and its relation with local atmospheric variables, simultaneous measurements of soil-emitted gamma radiation and potential gradient (defined from the vertical component of the atmospheric electric field) were taken every minute, along with local meteorological parameters (e.g., temperature, atmospheric pressure, relative humidity and daily solar radiation). The study region is Amieira, part of the Alqueva lake in Alentejo Portugal, where an interdisciplinary meteorological campaign, ALEX2014, took place from June to August 2014. Soil gamma radiation is more sensitive to small concentrations of radon as compared with alpha particles measurements, for that reason it is more suited for sites with low radon levels, as expected in this case. Preliminary results are presented here: statistical and spectral analysis show that i) the potential gradient has a stronger daily cycle as compared with the gamma radiation, ii) most of the energy of the gamma signal is concentrated in the low frequencies (close to 0), contrary to the potential gradient that has most of the energy in frequency 1 (daily cycle) and iii) a short-term relation between gamma radiation and the potential gradient has not been found. Future work and plans are also discussed. (paper)

  13. Development and evaluation of global radon transport model

    International Nuclear Information System (INIS)

    Kojima, H.; Nagano, K.

    2003-01-01

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

  14. Radon-calibrated emissions of CO2 from South Africa

    International Nuclear Information System (INIS)

    Gaudry, A.; Polian, G.; Ardouin, B.; Lambert, G.

    1990-01-01

    Atmospheric CO 2 and 222 Rn have been monitored at Amsterdam Island since 1980. Data were selected in order to eliminate any local influence. Typical CO 2 concentrations of the subantarctic marine atmosphere can be determined by selecting those values for which 222 Rn radioactivity was particularly low: less than 1 pCi m -3 . 222 Rn concentrations higher than 2 pCi m -3 are mainly due to injections into the subantarctic atmosphere from the continental source of South Africa. The passage of air masses under continental influence also shows typical CO 2 variations, well correlated with 222 Rn variations. From the knowledge of the global continental fluxes of 222 Rn, it has been possible to estimate CO 2 fluxes into the atmosphere from South Africa. The mean CO 2 flux corresponding to a 6-month period from May to October is about 5 millimole m -2 h -1 . Continental CO 2 emissions reach a maximum in August. (orig.)

  15. Study of the atmospheric chemistry of 218Po. Progress report, August 21, 1983-March 14, 1984

    International Nuclear Information System (INIS)

    Hopke, P.K.

    1984-03-01

    Studies have been completed that have demonstrated that there are two mechanisms for the neutralization of 218 Po + ions formed by the decay of 222 Rn. In the presence of oxygen, an oxide species is formed. It has been determined as part of the present work that this oxide species has an ionization potential in the range of 10.35 to 10.53 eV and that it can be neutralized by extracting electrons from lower ionization potential trace gases. It has also been found that a second mechanism is responsible for neutralization in the absence of oxygen. The behavior of NO 2 in the range of 50 ppB to 1 ppM in N 2 was explored. For NO 2 concentrations above 700 ppB, complete neutralization was observed. For lower concentrations, a concentration dependent degree of neutralization was observed. Studies are now being initiated to examine the kinetics of these neutralization processes. 27 references, 3 figures, 4 tables

  16. The GENIUS-test-facility first results on background from $^{222}$Rn daughters

    CERN Document Server

    Klapdor-Kleingrothaus, H V; Krivosheina, I V; Tomei, C; 10.1016/j.nima.2004.05.033

    2004-01-01

    GENIUS-TF (Nucl. Instr. and Meth. A 511 (2003) 341; Nucl. Instr. and Meth. A 481 (2002) 149.) is a test-facility for the GENIUS project (GENIUS-Proposal, 20 November 1997; Z. Phys. A 359 (1997) 351; CERN Courier, November 1997, 16; J. Phys. G 24 (1998) 483; Z. Phys. A 359 (1997) 361; in: H.V. Klapdor-Kleingrothaus, H. Pas. (Eds.), First International Conference on Particle Physics Beyond the Standard Model, Castle Ringberg, Germany, 8-14 June 1997, IOP Bristol (1998) 485 and in Int. J. Mod. Phys. A 13 (1998) 3953; in: H.V. Klapdor- Kleingrothaus, LV. Krivosheina (Eds.), Proceedings of the Second International Conference on Particle Physics Beyond the Standard Model BEYOND' 99, Castle Ringberg, Germany 6-12 June 1999, IOP Bristol (2000) 915), a proposed large scale underground observatory for rare events which is based on operation of naked germanium detectors in liquid nitrogen for an extreme background reduction. Operation of naked Ge crystals in liquid nitrogen has been applied routinely already for more th...

  17. Evolution of 222 Rn and chemical species related with eruptive processes of the Popocatepetl volcano

    International Nuclear Information System (INIS)

    Aranda Z, P.

    1998-01-01

    The study of the water quality for human consumption has always been great importance, considering the factors that can affect water quality as aquifers recharge and underground permeability. In this work, the behavior of three water springs related with the Popocatepetl volcano were studied within April 1997 and March 1998. The spring in Paso de Cortes in the municipality of Amecameca, State of Mexico, and the springs of Atlimeyaya and Axocopan in Atlixco, State of Puebla; the water of these last two springs is used for human consumption. The content of radon in water was determined by means of liquid scintillation, and a concentration of 1.22 Bq/l was found in the spring of Atlimeyaya, which represents 2 % of the maximum permissible level established by ICRP. A significant increase was observed in the Paso de Cortes spring in the month of July 1997. The content of radium, was determined by means of gamma spectrophotometry and small quantities of this element ( 2+ , Mg 2+ , K + , Na + , H C O 3 - , Cl - , S O 4 - 2 , Li, B, Sc, Ti, V, Rb, Sr and Ba, primarily, which did not show any significant variation with the change of seasons. No important variations in the concentration of radon, radium or for other volcanic activity related species were found in the entire study. (Author)

  18. Measurement uncertainties of long-term 222Rn averages at environmental levels using alpha track detectors

    International Nuclear Information System (INIS)

    Nelson, R.A.

    1987-01-01

    More than 250 replicate measurements of outdoor Rn concentration integrated over quarterly periods were made to estimate the random component of the measurement uncertainty of Track Etch detectors (type F) under outdoor conditions. The measurements were performed around three U mill tailings piles to provide a range of environmental concentrations. The measurement uncertainty was typically greater than could be accounted for by Poisson counting statistics. Average coefficients of variation of the order of 20% for all measured concentrations were found. It is concluded that alpha track detectors can be successfully used to determine annual average outdoor Rn concentrations through the use of careful quality control procedures. These include rapid deployment and collection of detectors to minimize unintended Rn exposure, careful packaging and shipping to and from the manufacturer, use of direct sunlight shields for all detectors and careful and secure mounting of all detectors in as similar a manner as possible. The use of multiple (at least duplicate) detectors at each monitoring location and an exposure period of no less than one quarter are suggested

  19. Radiological impact of phosphogypsum discharged into the Venice lagoon: 222Rn

    Science.gov (United States)

    Cantaluppi, C.; Ceccotto, F.; Cianchi, A.; Fasson, A.; Degetto, S.

    2012-04-01

    For about 20 years, between the 60 's and the 80 's of the last century, in the Passo a Campalto area (Lagoon of Venice - Italy) about 400,000 m3 of phosphogypsum (PG) were deposited at the border of the lagoon and next to urban areas without any environmental control. These materials are a by-product formed during the wet processing of phosphate rocks by sulphuric acid and have a significant environmental impact due to their abundance and their chemical-physical and radiochemical characteristics. The PG contains both chemical elements, which are considered dangerous for the ecosystems and natural radionuclides whose concentrations are much higher if compared to those typical for the Earth's crust. These discarded materials caused for many years the dispersion of radionuclides in the environment due to the tidal erosion, the re-suspension of radioactive inhalable dusts, the uncontrolled radon exhalation and the bioaccumulation of some radionuclides in the lagoon environment. After a decision of the appointed authorities, the Venice Water Authority (Ministry of Infrastructure and Transport), planned a permanent safety control of the site resulting in the complete isolation of the entire volume of contaminated materials from the environmental system. The entire project was specific for the particular features of the site and it required the improvement of analytical, sampling and measurement techniques in order to verify the effectiveness of the safety action. The radon assessment, in particular the check of the effectiveness of the inhibition of radon exhalation, is part of a more complex study, covering many other aspects of the management of a permanent disposal; they will be the object of further notes. The ultimate results of this study prove the efficacy of the intervention: radon concentrations in air and exhalation values from the restored area, measured during surveys, have been proved to be well in agreement with those of non contaminated soils.

  20. Influence of radon (222Rn) on hypothalamus, hypophysis, ovaries and uterus in Balb C strain mice

    International Nuclear Information System (INIS)

    Koziorowski, A.

    1997-01-01

    Curative properties of radon waters have been applied in balneotherapy for a long time. Therapeutic action is connected with radioactive properties of radon and the products of its degradation. All of them are the source of ionizing radiation, the alpha rays in particular. Radon therapy is widely applied to the treatment of many illnesses, especially of the circulatory system, rheumatism, and arthritis, bronchial asthma and many others. Good therapeutic results have also been achieved in gynecology to mention chronic inflammation of female reproductive organs and endocrinological disorders (of the ovary and during the period of sterilization). Positive results of radon therapy can also be associated with the influence of ionizing radiation on the activity of endocrine glands, mainly the axis hypothalamus - hypophysis - adrenal gland - ovary. There has been neither regular investigation into this problem nor into the morphology of the organs mentioned above. The present paper is an attempt to evaluate the influence of radon inhalations on the structure and function of hypothalamus, hypophysis ovary and uterus. This investigation was performed on hypothalamus, hypophysis, ovary and uterus in Balb C virgin mice. The total population of the mice under study was 140; with a control group of 40. The mice inhalated radon for 30 min. a day, starting with a single irradiation up to a 30-fold. I applied traditional histological techniques and immunocytochemical localization of selected hormones (FSH, LH, ADH). I also tried to evaluate the quantitative activity of mentioned glands by means of the computer morphometric and densitometric analyses of the immunocytochemical slides using an image analyzer Vidas 25 manufactured by Kontron. The results underwent statistical analysis. In order to examine the uterus the ultrastructural evaluation of its functioning was made. Moreover, I analyzed the concentration of FSH, LH, estrogens and progesterone in the serum by means of the immunochemical method. The investigations show that moderate radon inhalation (2 to 8 times) stimulate the mouse endocrine system and result in the increase of the synthesis and hormone secretion of the hypothalamus hypophysis ovary axis. In the analyzed cells of the hypothalamus the metabolic activity and cell proliferation are higher. The cells show intense immunocytochemical reaction. Similarly I observed the increase in gonadotropins of the hypophysis (FSH LH) in the serum of the irradiated mice when compared to the control group. The increase in gonadotropine in the serum is reflected in the functioning of the ovary. Irradiation of mice from 2 to 8 times significantly stimulates the functioning of the ovary without affecting its structure. In its cortical part one can sec at least a few maturing Graffian follicles. The ovaries stimulated in such a way secrete much more estrogens than in control group, and inhibit the progesterone synthesis and secretion. A more frequent irradiation of the ovary (more than 8 times) causes pathological changes. It is seen mainly within the cortex of the ovary especially in zona pellucida and granulosa cells of the mature follicles. I assume that the loss of the contact of the oocytes with granulosa cells can be cause of the oocyte division in the follicles observed on the slides. The increase in estrogens in the serum of the mice irradiated several times apart from observed in the same experimental conditions pathological changes in the granular cells (synthesizing this hormone), seems to be on the surface paradoxical. This marked increase in estrogens under such conditions can be the affect of the increased estrogen synthesis of the epinephros origin. Morphological data show that it is the result of the increased number of the ovary interstinal cells capable of synthesizing this hormone as the result of manifold irradiations. It seems that hypothalamus and hypophysis can also stimulate epinephros by the increased ADH secretion. In a similar way I can explain the increase in progesterone in the serum of the mice irradiated several times. Both the elements of the cortical part of the ovary and the epithelium of the endometrium and uterus glands show a strong reaction to radon irradiation. Under these conditions moderate irradiation number stimulates the activity of the endometrium what can reflect the increased ovary activity. However, we cannot exclude the immediate influence of the irradiation on the ovary and the uterus. Multiple mice irradiations cause several irreversible pathological changes, as shown by the ultrastructure of the analyzed cells of endometrium. The intensity of changes is in direct proportion to the number of irradiations which suggests a direct influence of radon radiation on these changes. Cellular respiration is the first process to be affected by irradiation, which is reflected by the ultrastracture of mitochondria. The degradation of cells integrity can cause to necrosis of the cell. The changes can be the result of direct influence of the radiation of the macromolecules of cells (enzymes, nucleic acids, structural proteins) or the result of ''free radicals'' generated by ionizing radiation disturbing indirectly the processes of cell metabolism The changes caused by radon inhalations should be taken into account in radon therapy of many illnesses. At the beginning the positive results of the treatment can shade the fact that further irradiation causes many changes, some of them irreversible, and even harmful. The presented results show that one must be cautious while applying the radon therapy both in the choice of patients and in the irradiation doses frequency not only in gynecology but also in other branches of medicine. (author)

  1. Preparation of gaseous CRMs from the primary system for "2"2"2Rn activity measurement

    International Nuclear Information System (INIS)

    Kim, B.J.; Kim, B.C.; Lee, K.B.; Lee, J.M.; Park, T.S.

    2016-01-01

    For disseminating the gaseous radon standard traceable to the KRISS primary system based on the defined solid angle counting method, two kinds of radon CRM (a glass ampule type and a stainless steel cylinder type) were developed. The activity of the CRM was certified by subtracting a residual activity from the measured activity by the primary system. After certification, the ampule CRM was used to calibrate a radon-monitoring instrument and the cylinder CRM to calibrate an HPGe system. We also improved the measurement procedure of the radon primary system. In a typical radon energy spectrum, the radon peak overlaps with the polonium peak. For more reliable and accurate measurement of radon activity, a fitting method was adopted for the evaluation of radon area in the alpha energy spectrum. The result of radon activity evaluated by using the fitting method is in good agreement with that by the previous integration method. - Highlights: • Preparation of gaseous Rn-222 CRMs from primary measurement system. • Convolution of 3 left-handed exponentials with a Gaussian function to count radon. • Calibration of continuous radon monitor using glass ampoule CRM. • Calibration of HPGe system as secondary standard for stainless steel cylinder CRM.

  2. Assessment of Indoor Radon (222Rn) Concentrations in the Vicinity of

    African Journals Online (AJOL)

    MLAY

    ABSTRACT. This study aimed to assess indoor radon concentrations in the vicinity of the Manyoni Uranium ... risk of lung cancer proportionally to the ... deposit, power plant, industrial radiation, etc. ... in foundations, walls, hollow concrete .... (AlphaGUARD User Manual 2007). ... used as control are presented in Table 4. The.

  3. Detailed effects of particle size and surface area on 222Rn emanation of a phosphate rock.

    Science.gov (United States)

    Haquin, Gustavo; Yungrais, Zohar; Ilzycer, Danielle; Zafrir, Hovav; Weisbrod, Noam

    2017-12-01

    The dependency of radon emanation on soil texture was investigated using the closed chamber method. Ground phosphate rock with a large specific surface area was analyzed, and the presence of inner pores, as well as a high degree of roughness and heterogeneity in the phosphate particles, was found. The average radon emanation of the dry phosphate was 0.145 ± 0.016. The emanation coefficient was highest (0.169 ± 0.019) for the smallest particles (210 μm). The reduction rate followed an inverse power law. As expected, a linear dependence between the emanation coefficient and the specific surface area was found, being lower than predicted for the large specific surface area. This was most likely due to an increase in the embedding effect of radon atoms in adjacent grains separated by micropores. Results indicate that knowledge of grain radium distribution is crucial to making accurate emanation predictions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Effect of 222Rn emanation from crystals on their 206Pb/238U age dating

    International Nuclear Information System (INIS)

    Barretto, Paulo M.C.

    2009-01-01

    The escape of radon from certain minerals with high uranium is of particular interest to those concerned with the determination of ages of rocks, minerals and tectonic events. To the extent that radon escapes, these minerals are not closed systems from the thermodynamic point of view and, more particularly, from the geochronological point of view. This investigation aimed to determine the radon escape from zircon crystals and how this fit into the severe isotopic constraints of the concordia dating model. To evaluate the consequences of radon loss on 238 U/ 206 Pb age dating methods, 20 zircon concentrates were analyzed. The observed range of relative percentage of radon loss was of 0.2-12 % and correlations with weathering of the crystals with natural alpha dose and with U-Pb age discordances were found. These correlations indicate relationships between the amount of lattice damage by radiation, the radon leakage out of the crystal and Pb mobility. Some of the stochastic complexities in specific age determinations are also discussed. (author)

  5. Environmental 222Rn as a background source in the solar neutrino experiment GALLEX

    International Nuclear Information System (INIS)

    Wojcik, M.

    1996-01-01

    The radiochemical neutrino experiment GALLEX is described. Its aim is to measure the flux of low energy solar neutrinos. In this experiment it is essential to suppress strongly the background of environmental origin, like charged cosmic rays, neutrons and gamma rays. In low-level radioactivity measurements performed in deep underground laboratory where flux of charged comic rays is strongly reduced, radon (Rn) exhaled from rock or concrete walls forms a most important strong, time-dependent background component. In this work the impact of Rn on the GALLEX experiment has been discussed and attempts to recognize and minimize its influence on the counter background were described. 63 refs, 22 figs, 11 tabs

  6. Analysis of international intercomparisons results organized by Japan for integrating 222Rn-220Rn detectors

    International Nuclear Information System (INIS)

    Wu Yunyun; Cui Hongxing; Zhang Qingzhao; Shang Bing; Su Xu

    2012-01-01

    Objective: To guarantee the quality of measurements with the radon-thoron discriminative detectors of our laboratory. Methods: LD-P radon-thoron discriminative detector participated in the international intercomparison for integrating radon/thoron detectors organized by National Institute of Radiological Science (NIRS, Japan). Detectors were sent to NIRS for exposure. Radon intercomparison was conducted with radon chamber providing three levels of exposure: low, medium and high levels. Thoron intercomparison was carried out at thoron chamber, which also provided three levels of exposure: low, medium and high levels. Detectors were posted back to our laboratory for etching and analysis after exposure. Then the measured values were submitted to NIRS. Finally the reference values were informed of us. Results: The relative percent difference (RPD) between the measured value and the reference value for radon was -13.8%, -14.4% and -17.1% at low, medium and high levels respectively, and that of thoron were -14.4%, 8.9% and -3.2% at three levels respectively. Conclusions: Both radon and thoron measurement of our detectors rank as 'Category Ⅰ' in the 4th international intercomparisons for integrating radon/thoron detectors with the NIRS radon/thoron chambers. (authors)

  7. Using {sup 222}Rn as a tracer of geophysical processes in underground environments

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, T.; Anjos, R. M. [LARA - Laboratório de Radioecologia e Alterações Ambientais, Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoatá, 24210-346, Niterói, RJ (Brazil); Valladares, D. L.; Rizzotto, M.; Velasco, H.; Rosas, J. P. de; Ayub, J. Juri [GEA - Instituto de Matemática Aplicada San Luis (IMASL), Universidad Nacional de San Luis, CCT-San Luis CONICET, Ej. de los Andes 950, D5700HHW San Luis (Argentina); Silva, A. A. R. da; Yoshimura, E. M. [Instituto de Física, Universidade de São Paulo, P.O. Box 66318, 05314-970, São Paulo, SP (Brazil)

    2014-11-11

    Radon levels in two old mines in San Luis, Argentina, are reported and analyzed. These mines are today used for touristic visitation. Our goal was to assess the potential use of such radioactive noble gas as tracer of geological processes in underground environments. CR-39 nuclear track detectors were used during the winter and summer seasons. The findings show that the significant radon concentrations reported in this environment are subject to large seasonal modulations, due to the strong dependence of natural ventilation on the variations of outside temperature. The results also indicate that radon pattern distribution appear as a good method to localize unknown ducts, fissures or secondary tunnels in subterranean environments.

  8. Using 222Rn as a tracer of geophysical processes in underground environments

    International Nuclear Information System (INIS)

    Lacerda, T.; Anjos, R. M.; Valladares, D. L.; Rizzotto, M.; Velasco, H.; Rosas, J. P. de; Ayub, J. Juri; Silva, A. A. R. da; Yoshimura, E. M.

    2014-01-01

    Radon levels in two old mines in San Luis, Argentina, are reported and analyzed. These mines are today used for touristic visitation. Our goal was to assess the potential use of such radioactive noble gas as tracer of geological processes in underground environments. CR-39 nuclear track detectors were used during the winter and summer seasons. The findings show that the significant radon concentrations reported in this environment are subject to large seasonal modulations, due to the strong dependence of natural ventilation on the variations of outside temperature. The results also indicate that radon pattern distribution appear as a good method to localize unknown ducts, fissures or secondary tunnels in subterranean environments

  9. A simple technique for the measurement of 222Rn in soil gas using LLRDS

    International Nuclear Information System (INIS)

    Karunakara, N.

    2010-01-01

    The details of the technique of soil gas measurement using LLRDS and results obtained for field measurements at different locations of Mangalore and the results of comparative study with the AlphaGuard along with the possible scope for the improvisation are presented and discussed in this paper

  10. Estimates concentrations in bottled 222Rn of the dose due to mineral waters in Iran

    International Nuclear Information System (INIS)

    Assadi, M. R.; Esmaealnejad, M.; Rahmatinejad, Z.

    2006-01-01

    Radon is a radionuclide that has the main role in exposure. Radon in water causes exposure in whole body but the largest dose being received by the stomach, as EPA (Environmental Protection Agency) estimates that radon in drinking water causes about 168 cancer deaths per year: 89 p ercent f rom lung cancer caused by breathing released to the indoor air from water and 11 p ercent f rom stomach cancer caused by consuming water containing radon. Now days the consumption of bottled mineral waters has become very popular. As is known, some kinds of mineral waters contain naturally occurring radionuclides in higher concentration than the usual drinking (tap) water. Surveys and reports on radon in most surface waters is low compared with radon level in groundwater and mineral water. In our work, the concentration of Rn(222) was determined in some bottled mineral waters available in Iran , and in next step the dose contribution ; due to ingestion ; for 1 l d -1 bottled mineral water consumption.

  11. Measurement of unattached aerosols of 222 Rn progeny by means of an electrostatic deposition method

    International Nuclear Information System (INIS)

    Canoba, Analia C.; Lopez, Fabio O.

    2001-01-01

    A method for the measurement of unattached radon progeny based on its electrostatic deposition onto wire screens, using only one pump, has been implemented and calibrated. The importance of being able of making use of this method is related with the special radiological significance that has the unattached fraction of the short-lived radon progeny. Because of this, the assesment of exposure could be directly related to dose with far greater accuracy than before.The advantages of this method are its simplicity, even with the tools needed for the sample collection, as well as the measurement instruments used. Also, the suitability of this method is enhanced by the fact that it can effectively be used with a simple measuring procedure such as the Kusnetz method. (author)

  12. Estimation of exposure to 222Rn from the excretion rates of 21πPb

    International Nuclear Information System (INIS)

    Holtzman, R.B.; Rundo, J.

    1981-01-01

    A model is proposed with which estimates of exposure to 227 Rn and its daughter products may be made from urinary excretion rates of 210 Pb. It is assumed that 20% of all the 210 Pb inhaled reaches the blood and that 50% of the endogenous excretion is through the urine. The estimates from the model are compared with the results of measurements on a subject residing in a house with high levels of radon. Whole body radioactivity and excretion data were consistent with the model, but the estimates of exposure (WL) were higher than those measured with an Environmental Working Level Monitor

  13. Environmental {sup 222}Rn as a background source in the solar neutrino experiment GALLEX

    Energy Technology Data Exchange (ETDEWEB)

    Wojcik, M. [Uniwersytet Jagiellonski, Cracow (Poland). Inst. Fizyki; BOREXINO

    1996-12-31

    The radiochemical neutrino experiment GALLEX is described. Its aim is to measure the flux of low energy solar neutrinos. In this experiment it is essential to suppress strongly the background of environmental origin, like charged cosmic rays, neutrons and gamma rays. In low-level radioactivity measurements performed in deep underground laboratory where flux of charged comic rays is strongly reduced, radon (Rn) exhaled from rock or concrete walls forms a most important strong, time-dependent background component. In this work the impact of Rn on the GALLEX experiment has been discussed and attempts to recognize and minimize its influence on the counter background were described. 63 refs, 22 figs, 11 tabs.

  14. Radiological impact of phosphogypsum discharged into the Venice lagoon: 222Rn

    Directory of Open Access Journals (Sweden)

    Fasson A.

    2012-04-01

    Full Text Available For about 20 years, between the 60 ’s and the 80 ’s of the last century, in the Passo a Campalto area (Lagoon of Venice - Italy about 400,000 m3 of phosphogypsum (PG were deposited at the border of the lagoon and next to urban areas without any environmental control. These materials are a by-product formed during the wet processing of phosphate rocks by sulphuric acid and have a significant environmental impact due to their abundance and their chemical-physical and radiochemical characteristics. The PG contains both chemical elements, which are considered dangerous for the ecosystems and natural radionuclides whose concentrations are much higher if compared to those typical for the Earth’s crust. These discarded materials caused for many years the dispersion of radionuclides in the environment due to the tidal erosion, the re-suspension of radioactive inhalable dusts, the uncontrolled radon exhalation and the bioaccumulation of some radionuclides in the lagoon environment. After a decision of the appointed authorities, the Venice Water Authority (Ministry of Infrastructure and Transport, planned a permanent safety control of the site resulting in the complete isolation of the entire volume of contaminated materials from the environmental system. The entire project was specific for the particular features of the site and it required the improvement of analytical, sampling and measurement techniques in order to verify the effectiveness of the safety action. The radon assessment, in particular the check of the effectiveness of the inhibition of radon exhalation, is part of a more complex study, covering many other aspects of the management of a permanent disposal; they will be the object of further notes. The ultimate results of this study prove the efficacy of the intervention: radon concentrations in air and exhalation values from the restored area, measured during surveys, have been proved to be well in agreement with those of non contaminated soils.

  15. Preliminary evaluation of 222Rn levels in homes and offices in two different regions in Syria

    International Nuclear Information System (INIS)

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

    1993-01-01

    Evaluation of Rn levels was carried out in homes and offices in Damascus and phosphate mining areas near Palmyra city in Syria. The AEOI radon diffusion dosimeters were used in this study. Electrochemical etching of polycarbonate detectors was used to develop the tracks. A standard source of radon was used for calibration. Radon levels were measured in 98 homes of workers in the phosphate mining areas and 29 homes in the Damascus region. The radon diffusion chambers were placed in offices and laboratories of AEC for about four months in average. The results gave an indication of Rn level in Damascus dwellings in spite of the necessity for further comprehensive studies for the city. The radon levels were high in some offices and laboratories where phosphate analyses are carried out or buildings near phosphate storage areas or near surface phosphate rocks occurrence, in comparison with homes. (author). 7 refs, 4 figs, 2 tabs

  16. The effect of the composition and production process of concrete on the 222Rn exhalation rate

    NARCIS (Netherlands)

    Jong, P. de; Dijk, W. van; Hulst, J.G.A. van; Heijningen, R.J.J. van

    1997-01-01

    In a series of 18 concrete samples, the influence of several parameters related to composition and production processes on the radon exhalation rate was studied. The investigated parameters were: amount and type of cement, water-cement ratio, curing conditions and curing time, type of aggregates,

  17. Environmental {sup 222}Rn as a background source in the solar neutrino experiment GALLEX

    Energy Technology Data Exchange (ETDEWEB)

    Wojcik, M [Uniwersytet Jagiellonski, Cracow (Poland). Inst. Fizyki; BOREXINO,

    1997-12-31

    The radiochemical neutrino experiment GALLEX is described. Its aim is to measure the flux of low energy solar neutrinos. In this experiment it is essential to suppress strongly the background of environmental origin, like charged cosmic rays, neutrons and gamma rays. In low-level radioactivity measurements performed in deep underground laboratory where flux of charged comic rays is strongly reduced, radon (Rn) exhaled from rock or concrete walls forms a most important strong, time-dependent background component. In this work the impact of Rn on the GALLEX experiment has been discussed and attempts to recognize and minimize its influence on the counter background were described. 63 refs, 22 figs, 11 tabs.

  18. Measurement of 222Rn concentration in drinking water in the environs of Thirthahalli taluk, Karnataka, India

    Directory of Open Access Journals (Sweden)

    G.M. Shilpa

    2017-07-01

    Full Text Available The dissolved radon concentration in water samples collected from various aquifers in and around Thirthahalli taluk was measured by employing active technique through Scintillation Radon Monitoring system. The measured radon concentration lies in the range of 0.37 ± 0.05 Bq/l to 87.02 ± 2.11 Bq/l. The resulting annual effective radiation dose to the public, who consume this water, lies in the range of 1.01μSvy−1 to 237.56 μSvy−1. However, no significant change in the radon concentration with respect to seasonal variation was observed in majority of the sample. Few samples show higher radon concentration during summer season and lower concentration in rainy season. All these results are presented in this paper.

  19. Improvements in real time {sup 222}Rn monitoring at Stromboli volcano

    Energy Technology Data Exchange (ETDEWEB)

    Lavagno, A., E-mail: andrea.lavagno@polito.it [Dipartimento di Scienze Applicata e Tecnologia, Politecnico di Torino (Italy); INFN, Sezione di Torino (Italy); Laiolo, M. [Dipartimento di Scienze della Terra, Università di Torino (Italy); Gervino, G. [Dipartimento di Fisica, Università di Torino (Italy); INFN, Sezione di Torino (Italy); Cigolini, C.; Coppola, D.; Piscopo, D. [Dipartimento di Scienze della Terra, Università di Torino (Italy); Marino, C. [Dipartimento di Fisica, Università di Torino (Italy); INFN, Sezione di Torino (Italy)

    2013-08-01

    Monitoring gas emissions from soil allow to get information on volcanic activity, hidden faults and hydrothermal dynamics. Radon activities at Stromboli were collected by means of multi-parametric real-time stations, that measure radon as well as environmental parameters. The last improvements on the detection system are presented and discussed.

  20. Investigation of 222Rn in subsurface waters as an earthquake predictor

    International Nuclear Information System (INIS)

    Smith, A.R.; Bowman, H.R.; Mosier, D.F.; Asaro, F.; Wollenberg, H.A.; King, C.Y.

    1976-01-01

    Changes of 222 Ra content of well waters in seismically active regions may provide earthquake precursor signals, according to reports of recent Chinese and Russian work. A high-precision γ-ray system for continuous monitoring of radon in wells and springs has been developed at the Lawrence Berkeley Laboratory, where monitoring began in April 1975, and has been extended to other sites including the San Andreas fault zone

  1. A passive environmental 222Rn monitor based on the exoelectron dosimeter

    International Nuclear Information System (INIS)

    Gammage, R.B.; Cheka, J.S.; Gesell, T.F.

    1978-01-01

    A high efficiency for BeO ceramic exoelectron dosimeters is demonstrated in the integrated monitoring of Mylar radon at concentrations close to natural background levels. Electrostatic collection of radon daughters onto aluminized mylar foil covering a BeO disk is achieved inside a porous, hemispherical chamber of the type developed by Costa-Ribeiro et al. This application of the exoelectron dosimeter for radon monitoring inside dwellings is a particularly favorable one; the lack of excessively high humidities and the clean conditions inside the hemisphere favor the reliable performance of the exoelectron dosimeter. Radon concentration - exposure times of 3 pCi h/l, or more, can be measured with an accuracy of about +-25% when the temperature and relative humidity are fluctuating. This means that radon concentrations of a few tenths of a pCi/l can be measured using exposure times of only a day or two. (Auth.)

  2. Kinetics of ingested 222Rn in humans determined from measurements with 133Xe. Project summary report

    International Nuclear Information System (INIS)

    Correia, J.A.; Weise, S.B.; Callahan, R.J.; Strauss, H.W.

    1987-12-01

    The problem of naturally occurring 222-radon contamination has received a great deal of public and scientific attention over the past several years, and has become a major public health issue worldwide. The purpose of the work reported in this document was to provide information about the behavior of ingested 222-radon in the digestive system and other organs of the human body. 133-Xenon, an element which behaves in the same manner as 222-radon in tissue and differs only in tissue solubility, was used in studies on human subjects. The tissue solubility differences were accounted for by using the tissue/blood partition coefficients of the two gases

  3. Measurement of concentrations of radon and its daughters in indoor atmosphere using CR-39 nuclear track detector

    International Nuclear Information System (INIS)

    Farid, S.M.

    1993-01-01

    This paper presents the results of the measurements of indoor 222 Rn and daughter levels in houses of different types located in different parts of Bangladesh. The passive time-integrated method of using a solid state nuclear track detector (CR-39) was employed for measuring both the 222 Rn gas concentration as well as the potential alpha energy exposure (PAEE) level from the short lived daughters of 222 Rn. The 222 Rn concentration from cup exposure and the PAEE from the bare exposure were obtained directly from the track density using calibration curves. A total of 275 exposures were made in the bare mode in 15 locations and 71 exposures in the cup mode in 6 locations. The geometric mean PAEE level obtained is 9.5 mWL with a geometric standard deviation of 1.9. The corresponding value for 222 Rn concentration are 61.3 Bq.M -3 and 2.4. The total data was collected over a period of one and a half year. The monthly variation of the geometric mean of PAEE is also shown. The annual effective dose equivalent has been estimated for each location by using the conversion factor of 9 mWv per WLM as obtained from ICRP-50. The average PAEE level obtained from the total data is below the intervention level as suggested by US EPA. However, the individual averages for each location show that in 8 out of 15 locations intervention may be considered and in others not intervention is called for. The 222 Rn concentrations at the seven locations are equal or less than the equilibrium equivalent 222 Rn concentration value as suggested by EPA. Attempts have also been made to see the variation in the PAEE levels according to different type of construction material used for the houses. (Author)

  4. Physical distributions of radon decay chain activities in air

    International Nuclear Information System (INIS)

    Rolle, R.

    2004-01-01

    The distribution of short-lived radon decay chain activities in air - in time, space and on aerosols - determines their exposure potential and measurement thereof. The radioactive decay constants and flow variables in a flow system combine, yielding activity concentration distributions and ratios of concentrations characteristic of the flow scheme, its source(s) and sink(s). The clock of 'internal' decay constants allows the unraveling of characteristics of the flow scheme from activity concentration measurements of individual members of a decay chain. Basic flow string calculations are shown. These can be assembled to define or simulate concentrations in a single- or multiple-compartment flow network. Response calculations to single- and multiple-step, or continuous changes in sources and sinks yield time-, spatial- and attachment-distributions. For the short-lived 222 Rn and 212 Pb decay chains the decay constants of the shorter-lived progeny in relation to the parent impose air activity ratios on successive chain members. Ratio limits had been used in the past to improve older grab-sampling- or integral gross-alpha measurement procedures for assessing exposure level. Assessment of individual concentrations, ratios and their distributions enables unravelling of dynamic flow systems, with restriction from the range of the parameters of flow and decay. An activity measuring instrument by itself represents a flow system with a response time distribution. Instrument response correction during continuous or quasi-continuous sampling and continuous spectrometric measurement allows far more accurate time-resolved measurement evaluation of continuously varying air concentrations, than previously attainable. Strong diurnal or even shorter (≤ 1 hr) changes probably are the norm in indoor and outdoor air activity concentrations. A mere average response evaluation, as used in steady state instrument calibration, and using less efficient instruments, is usually inadequate

  5. Radon source apportionment in the home, dosimetry and risk modeling. Final report, 1993-1997

    International Nuclear Information System (INIS)

    Harley, N.H.

    1998-01-01

    This research covered the following 3 topics in 4 years: (1) the source apportionment of 222 Rn in the home; (2) the internal bronchial dosimetry of inhaled 222 Rn decay products; and (3) the lung cancer risk from inhalation of the short lived decay products of 222 Rn. A 4th year of support was appended to this grant with a switch in research effort to determine a method for long term measurement of the particle size distribution of the short lived decay products in homes

  6. Nonlinear chaos-dynamical approach to analysis of atmospheric ...

    Indian Academy of Sciences (India)

    false nearest neighbors, Lyapunov's exponents, surrogate data, nonlinear prediction ... Chaotic dynamics; time series of the 222Rn concentration; universal complex ... tems is due to a number of applications, including the ..... Computer Engineering. ... Ternovsky,Quantum Systems in Physics, Chemistry, and. Biology, pp.

  7. Radioactive Decay

    Science.gov (United States)

    Radioactive decay is the emission of energy in the form of ionizing radiation. Example decay chains illustrate how radioactive atoms can go through many transformations as they become stable and no longer radioactive.

  8. Search for proton decay: introduction

    International Nuclear Information System (INIS)

    Goldhaber, M.

    1984-01-01

    In interpreting contained events observed in various proton decay detectors one can sometimes postulate, though usually not unambiguously, a potential decay mode of the proton, called a candidate. It is called a candidate, because for any individual event it is not possible to exclude the possibility that it is instead due to cosmic ray background, chiefly atmospheric neutrinos. Some consistency checks are proposed which could help establish proton decay, if it does occur in the presently accessible lifetime window

  9. A long range transport model of Rn-222

    International Nuclear Information System (INIS)

    Ikebe, Y.; Kojima, S.; Shimo, M.

    1993-01-01

    In this report, we propose an analytical treatment about temporal variation of 222 Rn concentration in the atmosphere with an aim to clarify origin and transport of 222 Rn. Based on the results of numerical simulation of radon, we separate the 222 Re concentration measured at Nagoya into the following two components : (1) 222 Rn atom originated near from the measuring site, which is denoted by 'diurnal variation component'. From numerical simulation of radon, it has been shown that the measured diurnal variation can be explained by this component. (2) 222 Rn atoms originated far from the measuring site (including Chinese Continent), which is denoted by 'background component'. For this component, we propose here a one layer transport model using air mass trajectory technique. By this model we can explain the temporal variation of background component and seasonal variation of 222 Rn at Nagoya. (3 figs.)

  10. Weak decays

    International Nuclear Information System (INIS)

    Wojcicki, S.

    1978-11-01

    Lectures are given on weak decays from a phenomenological point of view, emphasizing new results and ideas and the relation of recent results to the new standard theoretical model. The general framework within which the weak decay is viewed and relevant fundamental questions, weak decays of noncharmed hadrons, decays of muons and the tau, and the decays of charmed particles are covered. Limitation is made to the discussion of those topics that either have received recent experimental attention or are relevant to the new physics. (JFP) 178 references

  11. Experimental setup for radon exposure and first diffusion studies using gamma spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Andreas, E-mail: a.maier@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Beek, Patrick van [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Technical University Darmstadt, Hochschulstraße 6, 64289 Darmstadt (Germany); Hellmund, Johannes [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Durante, Marco [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Technical University Darmstadt, Hochschulstraße 6, 64289 Darmstadt (Germany); Schardt, Dieter; Kraft, Gerhard; Fournier, Claudia [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany)

    2015-11-01

    In order to measure the uptake and diffusion of {sup 222}Rn in biological material, an exposure chamber was constructed where cell cultures, biological tissues and mice can be exposed to {sup 222}Rn-activities similar to therapy conditions. After exposure, the material is transferred to a gamma spectrometer and the decay of {sup 214}Pb and {sup 214}Bi is analyzed. From the time kinetics of these decays the total amount of the initial {sup 222}Rn concentration can be calculated. In this paper the design and construction as well as first test measurements are reported.

  12. Energy-dependent etching-related impacts on CR-39 alpha detection efficiency for the Rn-222 and Rn-220 decay chains

    Science.gov (United States)

    Tan, Y.; Yuan, H.; Kearfott, K. J.

    2018-04-01

    CR-39 detectors are widely used to measure environmental levels of Rn-222, Rn-220 and their progeny. Prior research reported the CR-39 detection efficiency for alpha particles from Rn-222, Rn-220 and their progeny under a variety of etching conditions. This paper provides an explanation for interesting observations included in that work, namely that the critical incidence angle decreases with the increasing particle energy and the detection efficiency for 8.78 MeV alpha particles is zero. This paper explains these phenomena from a consideration of the interaction of alpha particles with the CR-39 detectors and the physics of etching dynamics. The proposed theory provides a rationale for an approach to optimizing the etching conditions of CR-39 detector for measuring Rn-222, Rn-220 and their progenies.

  13. Tau decays

    International Nuclear Information System (INIS)

    Golutvin, A.

    1994-09-01

    The most recent experimental results of τ physics are reviewed. The covered topics include precision measurements of semihadronic τ decay and their impact on tau branching ratio budget, the current status of the tau consistency test, a determination of Michel parameters and τ neutrino helicity, and upper limits on lepton-number violating τ decays. (orig.)

  14. Decay tank

    International Nuclear Information System (INIS)

    Matsumura, Seiichi; Tagishi, Akinori; Sakata, Yuji; Kontani, Koji; Sudo, Yukio; Kaminaga, Masanori; Kameyama, Iwao; Ando, Koei; Ishiki, Masahiko.

    1990-01-01

    The present invention concerns an decay tank for decaying a radioactivity concentration of a fluid containing radioactive material. The inside of an decay tank body is partitioned by partitioning plates to form a flow channel. A porous plate is attached at the portion above the end of the partitioning plate, that is, a portion where the flow is just turned. A part of the porous plate has a slit-like opening on the side close to the partitioning plate, that is, the inner side of the flow at the turning portion thereof. Accordingly, the primary coolants passed through the pool type nuclear reactor and flown into the decay tank are flow caused to uniformly over the entire part of the tank without causing swirling. Since a distribution in a staying time is thus decreased, the effect of decaying 16 N as radioactive nuclides in the primary coolants is increased even in a limited volume of the tank. (I.N.)

  15. The Raetrad model of radon generation and transport from soils into slab-on-grade houses

    International Nuclear Information System (INIS)

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

    1994-01-01

    Remediation planning and 222 Rn-related construction zoning require knowledge of how close and strong 226 Ra sources can be in different foundation soils under different groundwater conditions without excessively elevating indoor 222 Rn levels. A two-dimensional numerical-analytical model was developed to simulate (a) 222 Rn emanation, decay, and movement by diffusion and advection in soils around houses and in their understructures; and (b) 222 Rn accumulation in a single-zone house. The model represents foundation soils and a house in elliptical-cylindrical geometry. 222 Rn may diffuse through its floor slab or may enter via idealized cracks and openings. The model was validated with analytical calculations of two-dimensional air pressure fields and with one-dimensional calculations of 222 Rn generation with diffusion and diffusion combined with advection. Agreement generally was within 222 Rn measurements in two test-cell structures under passive and depressurized conditions averaged within 11% of measured values, well within measurement uncertainty. The corresponding average bias was only 3%. Larger variations were observed when applying the model to 50 houses. In this application, a negative bias of nearly 50% was observed due to data gaps and to poorly-characterized floor slabs and crack distributions. 41 refs., 11 fig., 3 tabs

  16. Use of radon-222 as a tracer in the study of atmospheric diffusion

    International Nuclear Information System (INIS)

    Ikebe, Y.; Yamada, H.; Nishimura, T.; Kojima, S.; Shimo, M.; Yamanishi, H.; Tojyo, K.; Iida, T.; Chino, M.

    1991-01-01

    222 Rn is one of the most useful tracer for studying the atmospheric diffusion. In this report, first we report analytical treatments about temporal variation of Rn concentration in the atmosphere to clarify origin and transport of Rn. Secondly we report the numerical simulation of the behavior of Rn. The results is compared with the observed Rn concentration for confirming the validity of the simulation. Based on the results of numerical analysis of a diffusion equation, we assumed that Rn concentration measured at Nagoya can be divided into the following two components: (I) Rn atom originated near from the measuring site, which is denoted by 'diurnal variation component'. For this, it was shown that the measured temporal variation can be explained by using ordinary non-steady state one dimensional diffusion equation. (II) Rn atoms originated far from the measuring site (including Chinese Continent), which is denoted by 'background component'. For this component, we propose a one layer transport model using air mass trajectory technique. By this model we can explain well the temporal variation of back-ground component and seasonal variation of Rn at Nagoya. A numerical simulation of the temporal variation of Rn was carried out for meso-regional scale (200kmx200kmx1km). The results was compared with the continuous measurements of Rn concentration at Nagoya, and fairly good agreements was obtained. We have obtained horizontal distributions of Rn around Nagoya (150kmx150km) for each season by using a passive method. The linear relationship between Rn concentration and measured Rn exhalation rate supports the transport model mentioned above and gives us other interesting informations. (author)

  17. High 210Po atmospheric deposition flux in the subtropical coastal area of Japan

    International Nuclear Information System (INIS)

    Tateda, Yutaka; Iwao, Kenji

    2008-01-01

    Bulk atmospheric deposition fluxes of 210 Po and 210 Pb were measured at three coastal regions of Japan, the Pacific Ocean coastal area of the Japanese mainland (Odawa Bay), the Chinese continental side of Japanese coastal area (Tsuyazaki), and an isolated island near Okinawa (Akajima). Wet and dry fallout collectors were continuously deployed from September 1997 through August 1998 for periods of 3 to 31 days depending on the frequency of precipitation events. Annual 210 Pb deposition fluxes at Odawa Bay (35 o N 139 o E), Tsuyazaki (33 o N 130 o E) and Akajima (26 o N 127 o E) were 73.3 ± 8.0, 197 ± 35 and 78.5 ± 8.0 Bq m -2 y -1 , respectively. Higher 210 Pb deposition was observed at the Chinese continental side of Japanese coast than at the Pacific Ocean coastal site. The high 210 Pb atmospheric flux at the Chinese continental side coast was thought to be attributable to 222 Rn-rich air-mass transport from the Chinese continent during the winter monsoon. In contrast, the annual 210 Po deposition fluxes at the three study sites were 13.0 ± 2.3 (Odawa Bay), 21.9 ± 4.4 (Tsuyazaki) and 58.4 ± 7.7 (Akajima) Bq m -2 y -1 , respectively, indicating unusual high 210 Po deposition at Akajima during winter. Anomalous unsupported 210 Po input was observed during summer 1997, suggesting unknown source of 210 Po at this area

  18. Indian Academy of Sciences Conference Series | Indian Academy of ...

    Indian Academy of Sciences (India)

    dynamical approach to the analysis and prediction of atmospheric radon 222Rn concentration using the beta particle activity data of radon monitors (with a pair of Geiger–Muller counters). The approach presented consistently includes a number ...

  19. Development of an Anisotropic Geological-Based Land Use Regression and Bayesian Maximum Entropy Model for Estimating Groundwater Radon across Northing Carolina

    Science.gov (United States)

    Messier, K. P.; Serre, M. L.

    2015-12-01

    Radon (222Rn) is a naturally occurring chemically inert, colorless, and odorless radioactive gas produced from the decay of uranium (238U), which is ubiquitous in rocks and soils worldwide. Exposure to 222Rn is likely the second leading cause of lung cancer after cigarette smoking via inhalation; however, exposure through untreated groundwater is also a contributing factor to both inhalation and ingestion routes. A land use regression (LUR) model for groundwater 222Rn with anisotropic geological and 238U based explanatory variables is developed, which helps elucidate the factors contributing to elevated 222Rn across North Carolina. Geological and uranium based variables are constructed in elliptical buffers surrounding each observation such that they capture the lateral geometric anisotropy present in groundwater 222Rn. Moreover, geological features are defined at three different geological spatial scales to allow the model to distinguish between large area and small area effects of geology on groundwater 222Rn. The LUR is also integrated into the Bayesian Maximum Entropy (BME) geostatistical framework to increase accuracy and produce a point-level LUR-BME model of groundwater 222Rn across North Carolina including prediction uncertainty. The LUR-BME model of groundwater 222Rn results in a leave-one out cross-validation of 0.46 (Pearson correlation coefficient= 0.68), effectively predicting within the spatial covariance range. Modeled results of 222Rn concentrations show variability among Intrusive Felsic geological formations likely due to average bedrock 238U defined on the basis of overlying stream-sediment 238U concentrations that is a widely distributed consistently analyzed point-source data.

  20. Fluxes and exchange rates of radon and oxygen across an air-sea interface

    International Nuclear Information System (INIS)

    Duenas, C.; Fernandez, M.C.; La Torre, M. de

    1986-01-01

    The flux of 222 Rn and O 2 from shallow water off the Bay of Malaga has been measured. The mean value of flux of 222 Rn is evaluated to be 74 atoms/m 2 · s. The Bay is a weak source of oxygen to the atmosphere, where the net production of oxygen is found to be 1.82 mol/m 2 · y. Moreover, the gas exchange rates of 222 Rn and O 2 across the air-sea interface has been determined by the radon method. The gas exchange rates and the wind speed have been estimated. (author)

  1. Atmospheric stability effects on potential radiological releases at a nuclear research facility in Romania: Characterising the atmospheric mixing state

    International Nuclear Information System (INIS)

    Chambers, Scott D.; Galeriu, Dan; Williams, Alastair G.; Melintescu, Anca; Griffiths, Alan D.; Crawford, Jagoda; Dyer, Leisa; Duma, Marin; Zorila, Bogdan

    2016-01-01

    A radon-based nocturnal stability classification scheme is developed for a flat inland site near Bucharest, Romania, characterised by significant local surface roughness heterogeneity, and compared with traditional meteorologically-based techniques. Eight months of hourly meteorological and atmospheric radon observations from a 60 m tower at the IFIN-HH nuclear research facility are analysed. Heterogeneous surface roughness conditions in the 1 km radius exclusion zone around the site hinder accurate characterisation of nocturnal atmospheric mixing conditions using conventional meteorological techniques, so a radon-based scheme is trialled. When the nocturnal boundary layer is very stable, the Pasquill–Gifford “radiation” scheme overestimates the atmosphere's capacity to dilute pollutants with near-surface sources (such as tritiated water vapour) by 20% compared to the radon-based scheme. Under these conditions, near-surface wind speeds drop well below 1 m s"−"1 and nocturnal mixing depths vary from ∼25 m to less than 10 m above ground level (a.g.l.). Combining nocturnal radon with daytime ceilometer data, we were able to reconstruct the full diurnal cycle of mixing depths. Average daytime mixing depths at this flat inland site range from 1200 to 1800 m a.g.l. in summer, and 500–900 m a.g.l. in winter. Using tower observations to constrain the nocturnal radon-derived effective mixing depth, we were able to estimate the seasonal range in the Bucharest regional radon flux as: 12 mBq m"−"2 s"−"1 in winter to 14 mBq m"−"2 s"−"1 in summer. - Highlights: • Site climatology accurately characterised by season and atmospheric stability class. • Comparison of "2"2"2Rn-based, Pasquill–Gifford and Richardson number stability indices. • Seasonal mixing depth estimates over the whole diurnal cycle by ceilometer and radon. • Seasonal variability in the regional radon source function well constrained.

  2. B decays

    CERN Document Server

    Stone, Sheldon

    1992-01-01

    The study of b quarks has now reached a stage where it is useful to review what has been learned so far and also to look at the implications of future studies. The most important observations thus far - measurement of the "B" lifetime, B 0 - B 0 mixing, and the observation of b? u transitions, as well as more mundane results on hadronic and semileptonic transitions - are described in detail by experimentalists who have been closely involved with the measurements. Theoretical progress in understanding b quark decays, including the mechanisms of hadronic and semileptonic decays, are described. S

  3. B decays

    CERN Document Server

    Stone, Sheldon

    1994-01-01

    This book reviews the study of b quarks and also looks at the implications of future studies. The most important observations thus far - including measurement of the ""B"" lifetime and observations of b -> u transitions - as well as the more mundane results of hadronic and semileptonic transitions are described in detail by experimentalists who have been closely involved with the measurements. Theoretical progress in understanding b quark decays, including the mechanisms of hadronic and semileptonic decays, are described. Synthesizing the experimental and theoretical information, the authors d

  4. 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)

  5. ATTILA - Atmospheric Tracer Transport In a Langrangian Model

    Energy Technology Data Exchange (ETDEWEB)

    Reithmeier, C.; Sausen, R.

    2000-07-01

    The Lagrangian model ATTILA (atmospheric tracer transport in a Lagrangian model) has been developed to treat the global-scale transport of passive trace species in the atmosphere within the framework of a general circulation model (GCM). ATTILA runs online within the GCM ECHAM4 and uses the GCM produced wind field to advect the centrois of 80.000 to 180.000 constant mass air parcels into which the model atmosphere is divided. Each trace constituent is thereby represented by a mass mixing ratio in each parcel. ATTILA contains state-of-the-art parameterizations of convection, turbulent boundary layer mixing, and interparcel transport and provides an algorithm to map the tracer concentrations from the trajectories to the ECHAM model grid. We use two experiments to evaluate the transport characteristics of ATTILA against observations and the standard semiLagrangian transport scheme of ECHAM. In the first experiment we simulate the distribution of the short-lived tracer Radon ({sup 222}Rn) in order to examine fast vertical transport over continents, and long-range transport from the continents to remote areas. In the second experiment, we simulate the distribution of radiocarbon ({sup 14}C) that was injected into the northern stratosphere during the nuclear weapon tests in the early 60ties, in order to examine upper tropospheric and stratospheric transport characteristics. ATTILA compares well to the observations and in many respects to the semiLagrangian scheme. However, contrary to the semiLagrangian scheme, ATTILA shows a greatly reduced meridional transport in the upper troposphere and lower stratosphere, and a reduced downward flux from the stratosphere to the troposphere, especially in midlatitudes. Since both transport schemes use the same model meteorology, we conclude that the often cited enhanced meridional transport and overestimated downward flux in ECHAM as described above is rather due to the numerical properties of the semiLagrangian scheme than due to an

  6. Atmospheric concentrations of 7Be, 10Be and 210Pb in northeast Asia

    International Nuclear Information System (INIS)

    Yamagata, T.; Tada, W.; T saito; Nagai, H.; Murayama, M.; Momoshima, N.; Matsuzaki, H.

    2005-01-01

    Cosmogenic nuclides 7 Be (T 1/2 = 53.3 d) and 10 Be (T 1/2 = 1.5 X 10 6 y) are very useful tracer for the aerosols originated in the upper atmosphere, In the case of 10 Be in surface air, however, two components from upper troposphere and from re-suspended dust from soil are mixed. We try to divide these sources, in order to know an interpretation of aerosol drives. To try to separate the two different source of 10 Be, we use 210 Pb (T 1/2 = 22.3y), progeny of 222 Rn, as continental component. In this study, the distribution of these nuclides in aerosols collected in the Northwest pacific and adjacent seas by employing the research Vessels as cut off the re-suspended dusts from soil are reported. Since research expeditions are mostly short term, continuous observation is very difficult. So we observed at Tokyo and Hachijo-Island, remote island located 300 km south from Tokyo, in 2002-2004. Seasonal variations for 7 Be, 10 Be and 210 Pb concentration were similar pattern at Tokyo and Hachijo-Island. The concentrations were high in April and October to November and low in July to August. Although 210 Pb concentration showed the seasonal variation similar to 7 Be concentration, the average 210 Pb concentration of Tokyo showed the value high about 35% as compared with Hachijo-Island, while the average 7 Be concentration having been mostly in agreement at both points. For the distribution of these nuclide, 7 Be and 10 Be concentrations in ocean air showed strong latitude dependence but 210 Pb concentration depend on distance from continent.

  7. Proton decay theory

    International Nuclear Information System (INIS)

    Marciano, W.J.

    1983-01-01

    Topics include minimal SU(5) predictions, gauge boson mediated proton decay, uncertainties in tau/sub p/, Higgs scalar effects, proton decay via Higgs scalars, supersymmetric SU(5), dimension 5 operators and proton decay, and Higgs scalars and proton decay

  8. London atmospheric Hydrogen and Carbon Monoxide: 12 year record, fluxes, and diurnal studies.

    Science.gov (United States)

    Lanoisellé, M.; Fisher, R. E.; Sriskantharajah, S.; Lowry, D.; Fowler, C. M. R.; Nisbet, E. G.

    2009-04-01

    Atmospheric hydrogen (H2) and carbon monoxide (CO) have been measured at the Royal Holloway site, 30km WSW of London, for 12 years. This site receives air that has passed over London when there are easterly winds and cleaner, background air when the wind comes from the SW. H2 and CO mixing ratios are measured continuously at 30 minute intervals on a Trace Analytical Reduction Gas Detector coupled to a HP5890 GC since September 1996, and on a Peak Performer I (or PP1) since July 2007 at 5 minute intervals. Both instruments use 2 1/8" packed columns in series: a Unibeads 1S and a Molecular Sieve 5A. The PP1 detector (Reduced Compound Photometer) is an updated version of the old RGD2, and both use zero air as the carrier gas. CO is calibrated twice a month against NOAA-CMDL standards (mixing ratios range: 186 to 300 ppb). H2 was uncalibrated until 2006, but is now calibrated monthly against internal standards (range 530 to 750 ppb) measured at MPI-Jena as part of the Eurohydros project. A linearity correction is applied to each instrument, based on the standard measurements. A secondary standard is measured before each sample on the GC-RGD and another one is measured 4 to 6 times in a row twice a day on the PP1. A target gas is measured daily on both instruments since September 2008. The secondary standards and the target gas are dry ambient air in 70L stainless steel tanks filled to a pressure of 8 bars. Comparison of results from the two instruments suggests that for the most part the data are in good agreement, but an interlaboratory round robin comparison exercise for the Eurohydros project showed that the RGD is not linear at low values of CO. This is particularly noticeable for CO levels below 150 ppb. The long-term record of CO at Royal Holloway shows a significant decline since the start of the record: the annual mean CO mixing ratio in 2008 was three times lower than in 1997. Flux calculations, by ratio against 222Rn, CH4 and CO2, suggest CO emissions

  9. Evolution of {sup 222} Rn and chemical species related with eruptive processes of the Popocatepetl volcano; Evolucion de {sup 222} Rn y especies quimicas relacionadas con procesos eruptivos del volcan Popocatepetl

    Energy Technology Data Exchange (ETDEWEB)

    Aranda Z, P

    1998-10-01

    The study of the water quality for human consumption has always been great importance, considering the factors that can affect water quality as aquifers recharge and underground permeability. In this work, the behavior of three water springs related with the Popocatepetl volcano were studied within April 1997 and March 1998. The spring in Paso de Cortes in the municipality of Amecameca, State of Mexico, and the springs of Atlimeyaya and Axocopan in Atlixco, State of Puebla; the water of these last two springs is used for human consumption. The content of radon in water was determined by means of liquid scintillation, and a concentration of 1.22 Bq/l was found in the spring of Atlimeyaya, which represents 2 % of the maximum permissible level established by ICRP. A significant increase was observed in the Paso de Cortes spring in the month of July 1997. The content of radium, was determined by means of gamma spectrophotometry and small quantities of this element (<0.11 Bq/l) were found. Water chemical analysis also included usual physical-chemical parameters determination by means of conventional methods. The spring of Axocopan, was found to have the major level of minerals, followed by Atlimeyaya and finally the Paso de Cortes spring, which is supplied by recent infiltrated water. Fluoride level showed a peak high level in concentration during the months of October and November, time in which infiltration due to rain is low; concentration level found was above the maximum permissible level established by Mexican authorities for this compound. The other chemical species determined were: Ca{sup 2+} , Mg{sup 2+} , K{sup +}, Na{sup +}, H C O{sub 3} {sup -} , Cl{sup -} , S O{sub 4} {sup -} {sup 2} , Li, B, Sc, Ti, V, Rb, Sr and Ba, primarily, which did not show any significant variation with the change of seasons. No important variations in the concentration of radon, radium or for other volcanic activity related species were found in the entire study. (Author)

  10. Measurement of unattached aerosols of {sup 222} Rn progeny by means of an electrostatic deposition method; Medicion de la fraccion no unida a aerosoles de la progenie de {sup 222} Rn mediante un metodo de deposicion electrostatica

    Energy Technology Data Exchange (ETDEWEB)

    Canoba, Analia C; Lopez, Fabio O [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina)

    2001-07-01

    A method for the measurement of unattached radon progeny based on its electrostatic deposition onto wire screens, using only one pump, has been implemented and calibrated. The importance of being able of making use of this method is related with the special radiological significance that has the unattached fraction of the short-lived radon progeny. Because of this, the assesment of exposure could be directly related to dose with far greater accuracy than before.The advantages of this method are its simplicity, even with the tools needed for the sample collection, as well as the measurement instruments used. Also, the suitability of this method is enhanced by the fact that it can effectively be used with a simple measuring procedure such as the Kusnetz method. (author)

  11. 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)

  12. Determination of 222Rn levels in houses, schools and hotels of Ramsar by AEOI passive radon diffusion dosimeters

    International Nuclear Information System (INIS)

    Sohrabi, M.; Zainali, H.; Mahdi, Sh.; Solaymanian, A.R.; Salehi, M.

    1993-01-01

    Radon-222 levels were determined in 473 rooms of about 350 houses, 16 schools in Ramsar and its high-level natural radiation areas (HLNRAs) as well as in 89 rooms and many locations of old and new Ramsar Hotels. The AEOI (Atomic Energy Organization of Iran) Radon Diffusion Dosimeters applying electrochemical etching of polycarbonate detectors were used indoors during different seasons. The levels measured ranged from 20 to 3700 Bq.m -3 , detected in Talesh Mahalleh which has the highest natural radiation level in the area, corresponding to effective dose equivalents (H e ) up to 98.5 mSv.a -1 . The mean radon levels determined in different regions were 615 Bq.m -3 in Talesh Mahalleh, 326 Bq.m -3 in Chaparsar, 258 Bq.m -3 in schools of Ramsar and its HLNRAs, 246 Bq.m -3 in Ramak, 111 Bq.m -3 in Rasmar city, 50 Bq.m -3 in Sadat Mahalleh and Katalom, 49 Bq.m -3 Tonekabon and 27 Bq.m -3 in Talesh Mahalleh of Katalom; and 90 Be.m -3 in old and 50 Bq.m -3 in new Ramsar Hotels. It was found that houses built at a higher level above the ground even in the areas with the highest gamma exposures have lower radon levels compared to those built directly on the ground. The results of the radon levels determined in the above regions indoors are presented. (author). 10 refs, 9 figs, 3 tabs

  13. 222Rn and CO2 soil-gas geochemical characterization of thermally altered clays at Orciatico (Tuscany, Central Italy)

    International Nuclear Information System (INIS)

    Voltattorni, N.; Lombardi, S.; Rizzo, S.

    2010-01-01

    Research highlights: → Soil-gas technique is applied to study gas permeability of Orciatico clay units. → Clay permeability depends on thermal and mechanical alteration degree. → Soil-gas distributions are due to shallow fracturing of clays. → Rn and CO 2 soil-gas anomalies highlight secondary permeability in clay sequence. → Soil-gas results are supported by detailed geoelectrical surveys. - Abstract: The physical properties of clay allow argillaceous formations to be considered geological barriers to radionuclide migration in high-level radioactive-waste isolation systems. As laboratory simulations are short term and numerical models always involve assumptions and simplifications of the natural system, natural analogues are extremely attractive surrogates for the study of long-term isolation. The clays of the Orciatico area (Tuscany, Central Italy), which were thermally altered via the intrusion of an alkali-trachyte laccolith, represent an interesting natural model of a heat source which acted on argillaceous materials. The study of this natural analogue was performed through detailed geoelectrical and soil-gas surveys to define both the geometry of the intrusive body and the gas permeability of a clay unit characterized by different degrees of thermal alteration. The results of this study show that gas permeability is increased in the clay sequences subjected to greater heat input from the emplacement of the Orciatico intrusion, despite the lack of apparent mineral and geotechnical variations. These results, which take into consideration long time periods in a natural, large-scale geological system, may have important implications for the long-term safety of underground storage of nuclear waste in clay formations.

  14. National survey on the natural radioactivity and 222Rn exhalation rate of building materials in The Netherlands.

    Science.gov (United States)

    de Jong, P; van Dijk, W; van der Graaf, E R; de Groot, T J H

    2006-09-01

    The present study reports on results of a nation-wide survey on the natural radioactivity concentrations and Rn exhalation rates of the prevailing building materials in the Netherlands. In total 100 samples were taken and analyzed for the activity concentrations of Ra, Ra, Th, and K and for their Rn exhalation rate. The sampled materials consisted of gypsum products, aerated concrete, sand-lime and clay bricks, mortars and concrete, representing about 95% of the stony building materials used in the construction of Dutch homes. The laboratory analyses were performed according to two well-documented standard procedures, the interlaboratory reproducibility of which is found to be within 5% on average. The highest radionuclide concentrations were found in a porous inner wall brick to which fly ash was added. The second highest were clay bricks with average Ra and Ra levels around 40 Bq kg. Concrete and mortar show the highest exhalation rates with a fairly broad range of 1 to 13 microBq (kg s). Low natural radioactivity levels are associated with either natural gypsum (products) or gypsum from flue gas desulphurization units, and low exhalation rates with clay bricks. To evaluate the radiological impact the radioactivity concentrations in each sample were combined into a so-called dose factor, representing the absorbed dose rate in a room with a floor, walls and ceiling of 20 cm of the material in question. For that purpose, calculations with the computer codes MCNP, Marmer and MicroShield on the specific absorbed dose rates were incorporated in the paper. The results of these codes corresponded within 6% and average values were calculated at 0.90, 1.10, and 0.080 nGy h per Bq kg for the U series, the Th series, and K, respectively. Model calculations on the external dose rate, based on the incidence of the various building materials in 1,336 living rooms, are in accordance with measured data.

  15. Radiation exposure of the population from 222Rn and other natural radionuclides around Mochovce nuclear power plant, Slovakia

    International Nuclear Information System (INIS)

    Bulko, Martin; Holy, Karol; Mullerova, Monika; Bohm, Radoslav; Pohronska, Zofia; Hola, Olga

    2017-01-01

    In this article, the effective dose to the population from natural sources of ionizing radiation in the vicinity of Mochovce nuclear power plant in Slovakia is presented. All major contributions to the effective dose were taken into account, including the contributions from gamma radiation of soil and rocks, cosmic radiation, and indoor and outdoor radon and thoron. On the basis of recent indoor radon measurements in Slovak cities and publicly available data about radon concentration in the soil air, a roughly linear relationship was found between these variables. Consequently, the annual effective dose from indoor radon and thoron was conservatively estimated. For the area of interest, a map of conservatively estimated potential effective doses was created. For the villages in the vicinity of Mochovce, the conservatively estimated effective dose to the population from natural sources ranged from 5.4 to 14.6 mSv, which is four orders of magnitude higher than the contribution of radioactive discharges from Mochovce nuclear power plant. (authors)

  16. IN-SITU RADIONUCLIDE TRANSPORT NEAR THE NOPAL I URANIUM DEPOSIT AT PENA BLANCA, MEXICO: CONSTRAINTS FROM SHORT-LIVED DECAY-SERIES RADIONUCLIDES

    International Nuclear Information System (INIS)

    Luo, S.; Ku, T.L.; Todd, V.; Murrell, M.; Pineda, J. Alfredo Rodriguez; Dinsmoor, J.; Mitchell, A.

    2005-01-01

    phases also contributes a significant source of 222 Rn to groundwater. It appears that the information obtained from this study provides useful testing and validation for the Yucca Mountain total system performance assessment model (TSPA)

  17. IN-SITU RADIONUCLIDE TRANSPORT NEAR THE NOPAL I URANIUM DEPOSIT AT PENA BLANCA, MEXICO: CONSTRAINTS FROM SHORT-LIVED DECAY-SERIES RADIONUCLIDES

    Energy Technology Data Exchange (ETDEWEB)

    S. Luo; T.L. Ku; V. Todd; M. Murrell; J. Alfredo Rodriguez Pineda; J. Dinsmoor; A. Mitchell

    2005-07-11

    in addition to alpha recoil, decay of {sup 226}Ra from the adsorbed phases also contributes a significant source of {sup 222}Rn to groundwater. It appears that the information obtained from this study provides useful testing and validation for the Yucca Mountain total system performance assessment model (TSPA).

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

    International Nuclear Information System (INIS)

    Harley, N.H.

    1992-01-01

    During the present 2 1/2 year contract period, we have made significant Progress in modeling the source apportionment of indoor 222 Rn and in 222 Rn decay product dosimetry. Two additional areas were worked on which we believe are useful for the DOE Radon research Program. One involved an analysis of the research house data, grouping the hourly house 222 Rn measurements into 2 day, 7 day and 90 day intervals to simulate the response of passive monitors. Another area requiring some attention resulted in a publication of 3 years of our indoor/outdoor measurements in a high-rise apartment. Little interest has been evinced in apartment measurements yet 20% of the US population lives in multiple-family dwellings, not in contact with the ground. These data together with a summary of all other published data on apartments showed that apartments have only about 50% greater 222 Rn concentration than the measured outdoor 222 Rn. Apartment dwellers generally represent a low risk group regarding 222 Rn exposure. The following sections describe the main projects in some detail

  19. Intercomparison study of atmospheric methane and carbon dioxide concentrations measured at the Ebre River Delta Station

    Science.gov (United States)

    Occhipinti, Paola; Morguí, Josep Anton; Àgueda, Alba; Batet, Oscar; Borràs, Sílvia; Cañas, Lídia; Curcoll, Roger; Grossi, Claudia; Nofuentes, Manel; Vazquez, Eusebi; Rodó, Xavier

    2015-04-01

    In the framework of the ClimaDat project, IC3 has established a network of eight monitoring stations across the Iberian Peninsula and the Canarian Archipelago with the aim of studying climate processes. The monitoring station at the Ebre River Delta (DEC3) is located in the Ebre River Delta Natural Park (40° 44' N; 0° 47' E) and it is characterized by the typical North-Western Mediterranean climate. Since 2013, atmospheric greenhouse gases (GHG) and 222Rn tracer gas together with the meteorological parameters are continuously measured from a 10 m a.g.l. height tower. Atmospheric GHG (CO2, CH4, CO and N2O) concentrations are determined using a Picarro analyzer G2301 (CO2 and CH4) and a modified gas chromatograph (GC) Agilent 6890N (CO2, CH4, CO and N2O). Open data access is available from the www.climadat.es website. Data collected at the DEC3 station are also submitted to the InGOS platform since this station is part of the InGOS European infrastructure project. Researchers from the Laboratory of the Atmosphere and the Oceans (LAO) at IC3 have performed an intercomparison study at the DEC3 site between three different Picarro analyzers (two Picarro G2301 and one Picarro G2301M), a Los Gatos Research (LGR) analyzer and the GC system already installed at the station. The aim of this study is to compare and assess the measuring agreement between the four optical gas analyzers and the GC. In the first part of the experiment, all instruments have been calibrated using NOAA gases as primary standards analyzing five Praxair provided targets to evaluate the precision of the measuring instruments. Max Plank Institute (MPI) gases have been used as secondary standards for the GC whereas Praxair provided tanks are used as secondary standards for the Picarro and the LGR analyzers. In the second part of the experiment, atmospheric GHG were measured from natural atmospheric air taken from a 10 m a.g.l. inlet. Daily cycles of GHG measurements were carried out using different

  20. Influence of Asian outflow on Rishiri Island, northernmost Japan: Application of radon as a tracer for characterizing fetch regions and evaluating a global 3D model

    Science.gov (United States)

    Zhu, Chunmao; Yoshikawa-Inoue, Hisayuki; Matsueda, Hidekadzu; Sawa, Yosuke; Niwa, Yosuke; Wada, Akira; Tanimoto, Hiroshi

    2012-04-01

    Atmospheric 222Rn was monitored from December 2008 to November 2010 on Rishiri Island (45°07‧N, 141°12‧E), northernmost Japan. Seasonal 222Rn variation was characterized by high concentrations from November to February and low concentrations from May to July, caused by the alternation of continental and maritime fetch regions. 222Rn tracer and back trajectory cluster analyses indicated that the predominant continental fetch region was southeastern Siberia and northeastern China. 222Rn emitted from China and South Korea, whose economies are growing rapidly, did not significantly affect the Rishiri site. The major maritime fetch region was the Sea of Okhotsk and the Bering Sea. A global three-dimensional model (NICAM-TM) accurately simulated 222Rn concentrations on Rishiri Island and in the seasonal fetch regions. The time series of 222Rn data will make it possible to evaluate the sources and sinks of atmospheric greenhouse gases being monitored at Rishiri Island, which complements other sites in the Asia-Pacific rim region, and to validate model simulations used to examine trans-boundary air pollution.

  1. Finding and evaluating potential radiological problems in the vicinity of uranium milling sites

    International Nuclear Information System (INIS)

    Goldsmith, W.A.; Yates, W.G.

    1982-01-01

    Tailings at inactive milling sites usually have a low frequency of human occupancy but continuously generate 222 Rn into the atmosphere. Measurements of airborne 222 Rn and 222 Rn flux are made on the sites to define the tailings source term. Concurrently with these measurements, an ambient 222 Rn monitoring network is established off-site and a meteolrololgical station is established at or near the mill site. Radioactivity can migrate to areas outside of site boundaries by wind and water erosion, groundwater transport, spillage of incoming purposes. In order to identify and assess off-site radioactivity on properties in the vicinity of milling sites, a combination of aerial and ground-level radiological monitoring techniques are used. The ground mobile gamma-ray scan is conducted using a vehicle equipped with sensitive gamma-ray detectors. The detectors are shielded so that gamma radiation input is viewed through only one side of the vehicle. This system is capable of precisely locating properties which have anomalously high gamma radiation levels caused by the presence of tailings. Subsequently, these properties are identified as candidate vicinity properties and are scheduled for radiological surveys subject to the property owner's consent. The comprehensive radiological surveys conducted at these vicinity properties determine the amount, type, and location of tailings materials. Structures on a vicinity property are carefully surveyed to determine the presence or absence of construction-related uses of tailings. If structural uses of tailings are found, air samples are analyzed for 222 Rn progeny, short-term continuous 222 Rn monitoring is instituted, and 222 Rn flux rate from tailings are estimated. If warranted, long-term 222 Rn and progeny measurements are made

  2. 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

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

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  4. Three-Phased Wake Vortex Decay

    Science.gov (United States)

    Proctor, Fred H.; Ahmad, Nashat N.; Switzer, George S.; LimonDuparcmeur, Fanny M.

    2010-01-01

    A detailed parametric study is conducted that examines vortex decay within turbulent and stratified atmospheres. The study uses a large eddy simulation model to simulate the out-of-ground effect behavior of wake vortices due to their interaction with atmospheric turbulence and thermal stratification. This paper presents results from a parametric investigation and suggests improvements for existing fast-time wake prediction models. This paper also describes a three-phased decay for wake vortices. The third phase is characterized by a relatively slow rate of circulation decay, and is associated with the ringvortex stage that occurs following vortex linking. The three-phased decay is most prevalent for wakes imbedded within environments having low-turbulence and near-neutral stratification.

  5. Evaluation of anthropogenic emissions of carbon monoxide in East Asia derived from the observations of atmospheric radon-222 over the western North Pacific

    International Nuclear Information System (INIS)

    Wada, A.; Matsueda, H.; Tsuboi, K.; Sawa, Y.; Murayama, S.; Taguchi, S.; Kamada, A.; Nosaka, M.

    2012-01-01

    We used the observed CO/"2"2"2Rn ratio in the Asian outflows at Minamitorishima (MNM), Yonagunijima (YON), and Ryori (RYO) in the western North Pacific from 2007 to 2011, together with a three-dimensional chemical transport model (STAG), in order to estimate anthropogenic emissions of CO in East Asia. The measurements captured high-frequency synoptic variations of enhanced "2"2"2Rn (ERN) events associated with the long-range transport of continental air masses. "2"2"2Rn and CO showed high correlation during the ERN events observed at MNM and YON in the winter and spring, but not at RYO. The STAG transport model reproduced well the concentrations of observed "2"2"2Rn when forced with a constant and uniform flux density of 1.0 atom cm"-"2 s"-"1, but underestimated the associated enhancement of synoptically variable CO caused by the underestimated flux values in the EDGAR ver. 4.1 emission database used in the model for East Asia. Better estimates for the East Asian emission were derived using a radon tracer method based on the difference in the enhancement ratio of CO/"2"2"2Rn between the observation and the model. The anthropogenic emissions of CO for China, Japan, and Korea were estimated to be 203 Tg CO yr"-"1, 91% of which originated in China. When compared with other estimated emissions of CO, our estimated result showed consistency with those of the inverse method, whereas the emission database of EDGAR was about 45% smaller than our anthropogenic estimation for China.

  6. Atmospheric neutrino fluxes

    International Nuclear Information System (INIS)

    Perkins, D.H.

    1984-01-01

    The atmospheric neutrino fluxes, which are responsible for the main background in proton decay experiments, have been calculated by two independent methods. There are discrepancies between the two sets of results regarding latitude effects and up-down asymmetries, especially for neutrino energies Esub(ν) < 1 GeV. (author)

  7. Atmospheric 210Pb changes during monsoon in east and west coast of Peninsular Malaysia

    International Nuclear Information System (INIS)

    Siti Munirah Johari; Che Abdul Rahim Mohamed

    2013-01-01

    Full-text: 210 Pb is widely used as an atmospheric tracer as its parent, 222 Rn is continuously produced in the atmosphere from soil emanation. This study was conducted to observe the changes of 210 Pb activity based on temporal and spatial factor using PM10 samples. PM10 were sampled by Malaysian Meteorological Department in four station consist of two station from both east and west coast of Peninsular Malaysia in 2007. Activity level of 210 Pb was determined using the Tennelec XLB-5 Gross Alpha-Beta Counter, Canberra, after the ingrowth of 210 Pb by the outgrowth of 210 Bi. Basically, the analysed result showed that three to four significant peaks during northeast monsoon, southwest monsoon and inter monsoon. For east coast which comprises Kuantan and Mersing stations, the highest 210 Pb activity in Kuantan was in April and June with 45.73 ± 3.66 mBq/ kg and 48.20 ± 3.33 mBq/ kg, respectively. While in Mersing, 210 Pb activity showed the highest in April and July with 45.77 ± 2.67 mBq/ kg and 44.21 ± 2.42 mBq/ kg, respectively. As for the west coast, it comprises Setiawan and Chuping stations. Setiawan station showed the highest 210 Pb activity in October and July with 48.90 ± 2.52 mBq/ kg and 44.09 ± 2.34 mBq/ kg, respectively. Chuping showed the highest 210 Pb activity in March and October with 39.96 ± 1.94 mBq/ kg and 14.98 ± 0.80 mBq/ kg, respectively. It shows that 210 Pb activity in Chuping is much lower than in Setiawan because of its location is in a rural area. This study showed that during southwest monsoon from May to September, it clearly showed that 210 Pb activity is higher in west coast than in east coast as wind sources come from southwest of Peninsular Malaysia. (author)

  8. Dental Caries (Tooth Decay)

    Science.gov (United States)

    ... Materials Contact Us Home Research Data & Statistics Dental Caries (Tooth Decay) Dental caries (tooth decay) remains the most prevalent chronic disease ... adults, even though it is largely preventable. Although caries has significantly decreased for most Americans over the ...

  9. Dental Caries (Tooth Decay)

    Science.gov (United States)

    ... Contact Us Home Research Data & Statistics Share Dental Caries (Tooth Decay) Dental caries (tooth decay) remains the most prevalent chronic disease ... adults, even though it is largely preventable. Although caries has significantly decreased for most Americans over the ...

  10. A process-based {sup 222}radon flux map for Europe and its comparison to long-term observations

    Energy Technology Data Exchange (ETDEWEB)

    Karstens, U. [Max-Planck-Instistut fuer Biogeochemie, Jena (Germany); Schwingshackl, C.; Schmithuesen, D.; Levin, I. [Heidelberg Univ. (Germany). Inst. fuer Umweltphysik

    2015-07-01

    Detailed {sup 222}radon ({sup 222}Rn) flux maps are an essential pre-requisite for the use of radon in atmospheric transport studies. Here we present a high-resolution {sup 222}Rn flux map for Europe, based on a parameterization of {sup 222}Rn production and transport in the soil. The {sup 222}Rn exhalation rate is parameterized based on soil properties, uranium content, and modelled soil moisture from two different land-surface reanalysis data sets. Spatial variations in exhalation rates are primarily determined by the uranium content of the soil, but also influenced by soil texture and local water-table depth. Temporal variations are related to soil moisture variations as the molecular diffusion in the unsaturated soil zone depends on available air-filled pore space. The implemented diffusion parameterization was tested against campaign-based {sup 222}Rn soil profile measurements. Monthly {sup 222}Rn exhalation rates from European soils were calculated with a nominal spatial resolution of 0.083 x 0.083 and compared to long-term direct measurements of {sup 222}Rn exhalation rates in different areas of Europe. The two realizations of the {sup 222}Rn flux map, based on the different soil moisture data sets, both realistically reproduce the observed seasonality in the fluxes but yield considerable differences for absolute flux values. The mean {sup 222}Rn flux from soils in Europe is estimated to be 10 mBq m{sup -2} s{sup -1} (ERA-Interim/Land soil moisture) or 15 mBq m{sup -2} s{sup -1} (GLDAS (Global Land Data Assimilation System) Noah soil moisture) for the period 2006-2010. The corresponding seasonal variations with low fluxes in winter and high fluxes in summer range in the two realizations from ca. 7 to ca. 14 mBq m{sup -2} s{sup -1} and from ca. 11 to ca. 20 mBq m{sup -2} s{sup -1}, respectively. These systematic differences highlight the importance of realistic soil moisture data for a reliable estimation of {sup 222}Rn exhalation rates. Comparison with

  11. A process-based 222radon flux map for Europe and its comparison to long-term observations

    Science.gov (United States)

    Karstens, U.; Schwingshackl, C.; Schmithüsen, D.; Levin, I.

    2015-11-01

    Detailed 222radon (222Rn) flux maps are an essential pre-requisite for the use of radon in atmospheric transport studies. Here we present a high-resolution 222Rn flux map for Europe, based on a parameterization of 222Rn production and transport in the soil. The 222Rn exhalation rate is parameterized based on soil properties, uranium content, and modelled soil moisture from two different land-surface reanalysis data sets. Spatial variations in exhalation rates are primarily determined by the uranium content of the soil, but also influenced by soil texture and local water-table depth. Temporal variations are related to soil moisture variations as the molecular diffusion in the unsaturated soil zone depends on available air-filled pore space. The implemented diffusion parameterization was tested against campaign-based 222Rn soil profile measurements. Monthly 222Rn exhalation rates from European soils were calculated with a nominal spatial resolution of 0.083° × 0.083° and compared to long-term direct measurements of 222Rn exhalation rates in different areas of Europe. The two realizations of the 222Rn flux map, based on the different soil moisture data sets, both realistically reproduce the observed seasonality in the fluxes but yield considerable differences for absolute flux values. The mean 222Rn flux from soils in Europe is estimated to be 10 mBq m-2 s-1 (ERA-Interim/Land soil moisture) or 15 mBq m-2 s-1 (GLDAS (Global Land Data Assimilation System) Noah soil moisture) for the period 2006-2010. The corresponding seasonal variations with low fluxes in winter and high fluxes in summer range in the two realizations from ca. 7 to ca. 14 mBq m-2 s-1 and from ca. 11 to ca. 20 mBq m-2 s-1, respectively. These systematic differences highlight the importance of realistic soil moisture data for a reliable estimation of 222Rn exhalation rates. Comparison with observations suggests that the flux estimates based on the GLDAS Noah soil moisture model on average better

  12. A process-based 222radon flux map for Europe and its comparison to long-term observations

    International Nuclear Information System (INIS)

    Karstens, U.; Schwingshackl, C.; Schmithuesen, D.; Levin, I.

    2015-01-01

    Detailed 222 radon ( 222 Rn) flux maps are an essential pre-requisite for the use of radon in atmospheric transport studies. Here we present a high-resolution 222 Rn flux map for Europe, based on a parameterization of 222 Rn production and transport in the soil. The 222 Rn exhalation rate is parameterized based on soil properties, uranium content, and modelled soil moisture from two different land-surface reanalysis data sets. Spatial variations in exhalation rates are primarily determined by the uranium content of the soil, but also influenced by soil texture and local water-table depth. Temporal variations are related to soil moisture variations as the molecular diffusion in the unsaturated soil zone depends on available air-filled pore space. The implemented diffusion parameterization was tested against campaign-based 222 Rn soil profile measurements. Monthly 222 Rn exhalation rates from European soils were calculated with a nominal spatial resolution of 0.083 x 0.083 and compared to long-term direct measurements of 222 Rn exhalation rates in different areas of Europe. The two realizations of the 222 Rn flux map, based on the different soil moisture data sets, both realistically reproduce the observed seasonality in the fluxes but yield considerable differences for absolute flux values. The mean 222 Rn flux from soils in Europe is estimated to be 10 mBq m -2 s -1 (ERA-Interim/Land soil moisture) or 15 mBq m -2 s -1 (GLDAS (Global Land Data Assimilation System) Noah soil moisture) for the period 2006-2010. The corresponding seasonal variations with low fluxes in winter and high fluxes in summer range in the two realizations from ca. 7 to ca. 14 mBq m -2 s -1 and from ca. 11 to ca. 20 mBq m -2 s -1 , respectively. These systematic differences highlight the importance of realistic soil moisture data for a reliable estimation of 222 Rn exhalation rates. Comparison with observations suggests that the flux estimates based on the GLDAS Noah soil moisture model on

  13. Radon and thoron emanation from various marble materials: impact on the workers

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Amghar, A.

    2005-01-01

    Uranium ( 238 U) and thorium ( 232 Th) concentrations were measured inside different pulverized marble material samples by using a method based on determining detection efficiencies of the CR-39 and LR-115 II solid state nuclear track detectors for the emitted alpha particles. Radon ( 222 Rn) and thoron ( 220 Rn) alpha-activities per unit volume were evaluated inside and outside the marble samples studied. Radon emanation coefficient was determined for the considered marble samples. Alpha- and beta-activities per unit volume of air due to radon, thoron and their progenies were measured in the atmosphere of a marble factory. Equilibrium factors between radon and its progeny and thoron and its decay products were evaluated in the air of the studied marble factory. The committed equivalent doses due to short-lived radon decay products were determined in different regions of the respiratory tract of workers in the considered marble factory

  14. Effect of spring water on the radon concentration in the air at Masutomi spa in Yamanashi Prefecture, Japan

    International Nuclear Information System (INIS)

    Inagaki, Masayo; Koga, Taeko; Morishima, Hiroshige; Kimura, Shojiro; Ohta, Masatoshi

    2012-01-01

    The concentrations of 222 Rn existing in air have been studied by using a convenient and highly sensitive Pico-rad detector system at Masutomi spa in Yamanashi Prefecture, Japan. The measurements in air were carried out indoors and outdoors during the winter of 2000 and the summers of 1999 and 2005. The concentrations of 222 Rn in spring water in this region were measured by the liquid scintillation method. The concentrations of natural radionuclides contained in soils surrounding spa areas were also examined by means of the γ-ray energy spectrometry technique using a Ge diode detector to investigate the correlation between the radionuclides contents and 222 Rn concentrations in air at each point of interest. The atmospheric 222 Rn concentrations in these areas were high, ranging from 5 Bq/m 3 to 2676 Bq/m 3 . The radon concentration at each hotel was high in the order of the bath room, the dressing room, the lobby, and the outdoor area near the hotel, with averages and standard deviations of the concentration of 441 ± 79 Bq/m 3 , 351 ± 283 Bq/m 3 , 121 ± 5 Bq/m 3 , and 23 ± 1 Bq/m 3 , respectively. The source of 222 Rn in the air in the bath room is more likely to be the spring water than the soil. The spring water plays carries the radon to the atmosphere. Our measurements indicated that the 222 Rn concentration in the air was affected by the 222 Rn concentration in spring water rather than that in soil. (author)

  15. Staging atmospheres

    DEFF Research Database (Denmark)

    Bille, Mikkel; Bjerregaard, Peter; Sørensen, Tim Flohr

    2015-01-01

    The article introduces the special issue on staging atmospheres by surveying the philosophical, political and anthropological literature on atmosphere, and explores the relationship between atmosphere, material culture, subjectivity and affect. Atmosphere seems to occupy one of the classic...

  16. SYMPOSIUM: Rare decays

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1989-04-15

    Late last year, a symposium entitled 'Rare Decays' attracted 115 participants to a hotel in Vancouver, Canada. These participants were particle physicists interested in checking conventional selection rules to look for clues of possible new behaviour outside today's accepted 'Standard Model'. For physicists, 'rare decays' include processes that have so far not been seen, explicitly forbidden by the rules of the Standard Model, or processes highly suppressed because the decay is dominated by an easier route, or includes processes resulting from multiple transitions.

  17. Effective Majorana neutrino decay

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Lucia [Instituto de Fisica, Facultad de Ingenieria,Universidad de la Republica, Montevideo (Uruguay); Romero, Ismael; Peressutti, Javier; Sampayo, Oscar A. [Universidad Nacional de Mar del Plata, Departamento de Fisica, Instituto de Investigaciones Fisicas de Mar del Plata (IFIMAR) CONICET, UNMDP, Mar del Plata (Argentina)

    2016-08-15

    We study the decay of heavy sterile Majorana neutrinos according to the interactions obtained from an effective general theory. We describe the two- and three-body decays for a wide range of neutrino masses. The results obtained and presented in this work could be useful for the study of the production and detection of these particles in a variety of high energy physics experiments and astrophysical observations. We show in different figures the dominant branching ratios and the total decay width. (orig.)

  18. Axigluon decays of toponium

    International Nuclear Information System (INIS)

    Faustov, R.N.; Vasilevskaya, I.G.

    1990-01-01

    Chiral-colour model predicts the existence of axigluons which is an octet of massive axial-vector gauge bosons. In this respect toponium decays into axigluons and gluons are of interest. The following toponium decays are considered: θ → Ag, θ → AAg, θ → ggg → AAg. The width of toponium S-state decays is calculated under various possible values of axigluon mass

  19. Decay of 143La

    International Nuclear Information System (INIS)

    Blachot, J.; Dousson, S.; Monnand, E.; Schussler, F.

    1976-01-01

    The decay of 143 La has been investigated. Sources have been obtained from 2 isotope separators (ISERE, OSIRIS). 12 gamma rays, with the most intense at 620keV representing only 1.4% of decay, have been attributed to the 143 La decay. A level scheme has been found and compared with the one deduced from (d,p) and (n,γ) reactions on 142 Ce [fr

  20. Environmental radioactivity of radon daughter's radionuclides 210Pb-210Bi-210Po

    International Nuclear Information System (INIS)

    Momoshima, N.

    2003-01-01

    Radionuclide, 210 Pb(22.3 y)- 210 Bi(5.013 d)- 210 Po(138.4 d) belongs to the uranium decay chain and widely distributed in the environment. 222 Rn escaped from the earth surface is a major source of atmospheric 210 Pb. These nuclides attach with atmospheric aerosols and are removed to the ground as wet and dry depositions. The residence time of the atmospheric aerosol, thus, was obtained by activity ratios of 210 Bi/ 210 Pb and 210 Po/ 210 Pb, showing different values. The discrepancy on the residence times are explained with inputs of 210 Po to the atmosphere other than 222 Rn emanated from the earth surface. The removal of aerosol as wet deposition occupies a significant fraction, which reaches 72% on 210 Pb and 89% on 7 Be. In the ocean, the radionuclides are used as tracer to examine dynamic processes occurring in the ocean, such as removal of particulate matter from seawater column to bottom. The 210 Pb and 210 Po concentrations in the ocean water collected off continent decreased from surface toward bottom, and the shortage on 210 Po content relative to that of 210 Po was observed at shallow ocean layers, however, the 210 Po/ 210 Pb activity ratio closed to the radioactive equilibrium at deeper layers. The 210 Pb is a very good tracer to evaluate an accumulation rate of bottom sediment in ocean, lake and river. This is called as 210 Pb dating and is successfully applicable to accumulation circumstances that bottom sediment deposits at constant rate. Most of the actual cases, simultaneous 137 Cs dating is carried out, which uses 137 Cs peak in the core as originated from radioactive fallout of nuclear tests, showing the maximum in 1963. Recently new findings on source of atmospheric 210 Po are report by laboratory experiments and environmental measurements, which proves biologically supported emission of volatile Po compounds to the atmosphere. (author)

  1. Natural radioactivity in environmental studies

    International Nuclear Information System (INIS)

    Heijnis, H.; Jenkinson, A.; Chisari, R.

    1998-01-01

    Full text: The use natural radioactivity in environmental studies has proven a very powerful tool to determine the dynamics of both natural and antrophogenic processes in our environment. The use of 14 C in archeology and past climate studies has led to many scientific discoveries (i.e. shroud of Turin and Utze 'the ice-man' from Austria). The use of the 238 U-decay series is of at least equal value to studies in archeology and past climates. Some of the Isotopes studied supplement 14 C (which is limited to 40,000 years) up to 350,000 years and others can be utilized to date very young sediments, which can't be dated by 14 C. The so-called 210 Pb dating method has been used over the past 3 decades to date recent sediment. The method uses the disequilibrium in the 238 U decay chain, caused by the escape of the intermediate daughter 222 Rn (a noble gas) from the earth's crust. In the atmosphere the 222 Rn decays via short-lived daughter isotopes to 210 Pb. This 210 Pb with a very convenient half-life of 22,3 years decays to stable 206 Pb. By measuring the surface activity of a sediment core and subsequent samples at regular intervals one can establish a chronology for the sediment core. By studying the trace metals in these cores, one could deduce a contamination history for the region. Examples of studies supported by AINSE and ANSTO will be given

  2. Photons coming from an opaque obstacle as a manifestation of heavy neutrino decays

    Science.gov (United States)

    Reynoso, Matías M.; Romero, Ismael; Sampayo, Oscar A.

    2018-05-01

    Within the framework of physics beyond the standard model, we study the possibility that mesons produced in the atmosphere by the cosmic-ray flux decay to heavy Majorana neutrinos and the latter, in turn, decay mostly to photons in the low-mass region. We study the photon flux produced by sterile Majorana neutrinos (N ) decaying after passing through a massive and opaque object such as a mountain. To model the production of N 's in the atmosphere and their decay to photons, we consider the interaction between the Majorana neutrinos and the standard matter as modeled by an effective theory. We then calculate the heavy neutrino flux originated by the decay of mesons in the atmosphere. The surviving photon flux, originated by N decays, is calculated using transport equations that include the effects of Majorana neutrino production and decay.

  3. Induced nuclear beta decay

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1986-01-01

    Certain nuclear beta decay transitions normally inhibited by angular momentum or parity considerations can be induced to occur by the application of an electromagnetic field. Such decays can be useful in the controlled production of power, and in fission waste disposal

  4. B decays to baryons

    Indian Academy of Sciences (India)

    We note that two-body decays to baryons are suppressed relative to three- and four-body decays. In most of these analyses, the invariant baryon–antibaryon mass shows an enhancement near the threshold. We propose a phenomenological interpretation of this quite common feature of hadronization to baryons.

  5. Multiple preequilibrium decay processes

    International Nuclear Information System (INIS)

    Blann, M.

    1987-11-01

    Several treatments of multiple preequilibrium decay are reviewed with emphasis on the exciton and hybrid models. We show the expected behavior of this decay mode as a function of incident nucleon energy. The algorithms used in the hybrid model treatment are reviewed, and comparisons are made between predictions of the hybrid model and a broad range of experimental results. 24 refs., 20 figs

  6. Aspects of B decays

    International Nuclear Information System (INIS)

    Faller, Sven

    2011-01-01

    B-meson decays are a good probe for testing the flavour sector of the standard model of particle physics. The standard model describes at present all experimental data satisfactorily, although some ''tensions'' exist, i.e. two to three sigma deviations from the predictions, in particular in B decays. The arguments against the standard model are thus purely theoretical. These tensions between experimental data and theoretical predictions provide an extension of the standard model by new physics contributions. Within the flavour sector main theoretical uncertainties are related to the hadronic matrix elements. For exclusive semileptonic anti B → D (*) l anti ν decays QCD sum rule techniques, which are suitable for studying hadronic matrix elements, however, with substantial, but estimable hadronic uncertainties, are used. The exploration of new physics effects in B-meson decays is done in an twofold way. In exclusive semileptonic anti B → D (*) l anti ν decays the effect of additional right-handed vector as well as left- and right-handed scalar and tensor hadronic current structures in the decay rates and the form factors are studied at the non-recoil point. As a second approach one studied the non-leptonic B 0 s →J/ψφ and B 0 →J/ψK S,L decays discussing CP violating effects in the time-dependent decay amplitudes by considering new physics phase in the B 0 - anti B 0 mixing phase. (orig.)

  7. The importance of recent results from epidemiology

    International Nuclear Information System (INIS)

    Harley, N.H.; Robbins, E.S.

    1992-01-01

    The underground miner radon epidemiology reported in the past 15 years has led to modeling of the lung cancer risk from 222 Rn exposure, quantitating the risk in present day mines, extrapolating the risk to environmental 222 Rn exposure, and relating effects of low and high LET radiation. Many countries have occupational guidelines that now better conform to the actual risks experienced in mining and some have governmental guidelines regarding environmental exposure which, when fully implemented, can impose substantial benefit but also substantial cost to society. For this reason it important to follow the health of underground mining populations to better understand the risk that has been deduced, inferred or calculated. The purpose of this report is to describe the most recent results and advances. In this examination a biological basis for a new model for 222 Rn decay product risk is developed

  8. Radon in underground waters as a natural analogue to study the escape of CO2 in geological repositories.

    Science.gov (United States)

    Martín Sánchez, A; Ruano Sánchez, A B; de la Torre Pérez, J; Jurado Vargas, M

    2015-11-01

    Activity concentrations of dissolved (222)Rn and (226)Ra were measured in several underground aquifers, which are candidates for repositories or for the study of analogue natural escapes of CO2. The concentration of both radionuclides in water was determined using liquid scintillation counting. The values obtained for the (222)Rn concentrations varied from 0 to 150 Bq l(-1), while the levels of (226)Ra were in general very low. This indicates that (222)Rn is coming from the decay of the undissolved (226)Ra existing in the rocks and deep layers of the aquifers, being later transported by diffusion in water. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Decay of hypernuclei

    International Nuclear Information System (INIS)

    Bando, H.

    1985-01-01

    The pionic and non-mesonic decays of hypernuclei are discussed. In the first part, various decay processes which could be useful to obtain information of hypernuclear structure are discussed. The experimental data concerning the pionic and non-mesonic decays are discussed in the second part. As the experimental data, there are only few lifetime data and some crude data on the non-mesonic to π decay ratio. In the third and the fourth parts, some theoretical analyses are made on the pionic and the nonmesonic decays. DDHF calculation was performed for Λ and N systems by using Skyrme type ΛN and NN effective interactions. A suppression factor of the order of 10 -3 for A nearly equal 100 was obtained. (Aoki, K.)

  10. Rare Decays at LHCb

    CERN Document Server

    Belyaev, Ivan

    2006-01-01

    Rare loop-induced decays are sensitive to New Physics in many Standard Model extensions. In this paper we discuss the reconstruction of the radiative penguin decays $B^0_d \\to K^{*0} \\gamma, B^0_s \\to \\phi \\gamma , B^0_d \\to \\omega \\gamma, \\Lambda_b \\to \\Lambda \\gamma$, the electroweak penguin decays $B^0_d \\to K^{*0} \\mu^+ \\mu^-, B^+_u \\to K^+ \\mu^+ \\mu^-$, the gluonic penguin decays $B^0_d \\to \\phi K^0_S, B^0_s \\to \\phi \\phi$, and the decay $B^0_s \\to \\mu^+\\mu^-$ at LHCb. The selection criteria, evaluated efficiencies, expected annual yields and $B/S$ estimates are presented.

  11. Surface Alpha Interactions in P-Type Point-Contact HPGe Detectors: Maximizing Sensitivity of 76Ge Neutrinoless Double-Beta Decay Searches

    Science.gov (United States)

    Gruszko, Julieta

    Though the existence of neutrino oscillations proves that neutrinos must have non-zero mass, Beyond-the-Standard-Model physics is needed to explain the origins of that mass. One intriguing possibility is that neutrinos are Majorana particles, i.e., they are their own anti-particles. Such a mechanism could naturally explain the observed smallness of the neutrino masses, and would have consequences that go far beyond neutrino physics, with implications for Grand Unification and leptogenesis. If neutrinos are Majorana particles, they could undergo neutrinoless double-beta decay (0nBB), a hypothesized rare decay in which two antineutrinos annihilate one another. This process, if it exists, would be exceedingly rare, with a half-life over 1E25 years. Therefore, searching for it requires experiments with extremely low background rates. One promising technique in the search for 0nBB is the use of P-type point-contact (P-PC) high-purity Germanium (HPGe) detectors enriched in 76Ge, operated in large low-background arrays. This approach is used, with some key differences, by the MAJORANA and GERDA Collaborations. A problematic background in such large granular detector arrays is posed by alpha particles incident on the surfaces of the detectors, often caused by 222Rn contamination of parts or of the detectors themselves. In the MAJORANA DEMONSTRATOR, events have been observed that are consistent with energy-degraded alphas originating near the passivated surface of the detectors, leading to a potential background contribution in the region-of-interest for neutrinoless double-beta decay. However, it is also observed that when energy deposition occurs very close to the passivated surface, high charge trapping occurs along with subsequent slow charge re-release. This leads to both a reduced prompt signal and a measurable change in slope of the tail of a recorded pulse. Here we discuss the characteristics of these events and the development of a filter that can identify the

  12. Investigation of the concentrations of radon-222 and its daughter products in Loutraki spas (Peloponnese, Greece)

    International Nuclear Information System (INIS)

    Kritidis, Panaiotis; Angelou, Panaiotis.

    1984-07-01

    An express variant of the three-interval total alpha-counting filter method being suitable for the determination of elevated concentrations of 222 Rn decay products in air of increased humidity is described. The method has been used for the determination of radon daughters in air in the major radon spas of Loutraki. Concentrations of 222 Rn and 226 Ra in spa water have been determined as well. Annual effective dose equivalents for the personnel and the patients have been estimated. The need of certain radiation protection measures is pointed out. (author)

  13. RADON 222 AND TROPOSPHERIC VERTICAL TRANSPORT.

    OpenAIRE

    Liu, SC; McAfee, JR; Cicerone, RJ

    1984-01-01

    Radon 222 is an inert gas whose loss is due only to radioactive decay with a half life of 3. 83 days (5. 51-day 'exponential' lifetime). It is a very useful tracer of continental air because only ground level continental sources are significant. Previously published measured **2**2**2Rn profiles are analyzed here by averaging for the summer, winter, and spring-fall seasons. The analysis shows that in summer, about 55% of the **2**2**2Rn is transported above the planetary boundary layer, consi...

  14. Jovian atmospheres

    International Nuclear Information System (INIS)

    Allison, M.; Travis, L.D.

    1986-10-01

    A conference on the atmosphere of Jupiter produced papers in the areas of thermal and ortho-para hydrogen structure, clouds and chemistry, atmospheric structure, global dynamics, synoptic features and processes, atmospheric dynamics, and future spaceflight opportunities. A session on the atmospheres of Uranus and Neptune was included, and the atmosphere of Saturn was discussed in several papers

  15. 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

  16. Determination of indoor radon concentrations at the elementary schools of Fatih district in Istanbul

    Energy Technology Data Exchange (ETDEWEB)

    Kurt, A., E-mail: aziz.kurt@istanbul.edu.tr; Yalcin, L. Sahin, E-mail: latife.sahin@gmail.com; Oktem, Y., E-mail: sgyks@istanbul.edu.tr; Akkus, B., E-mail: akkus@istanbul.edu.tr; Bozkurt, E., E-mail: enginbozkurt88@gmail.com; Hafizoglu, N., E-mail: nurgulhfz87@gmail.com; Ozturk, F. C., E-mail: fcaglaozturk@gmail.com; Aytan, O., E-mail: ozgur@aytan.net; Ertoprak, A., E-mail: aysegulertoprak@gmail.com [Istanbul University, Science Faculty, Physics Department, 34134, Istanbul (Turkey)

    2016-03-25

    Radon is an odorless, tasteless, colorless noble radioactive gas which is produced within the radioactive decay chain of Uranium. The Radon forms in rocks, diffuses into soil and then escapes into atmosphere. When human exposure to high concentration of radon gas from inside, risk of developing lung cancer is increased. There are many methods to determine {sup 222}Rn concentration in the air. In this study, radon concentration of confined air spaces were measured by using LR-115 solid state nuclear track detectors. 509 LR-115 nuclear trace detectors were placed to 25 schools in Fatih District and they effective dose values were calculated. The results of measurements showed that the radon concentration varies between 40-395 Bq/m{sup 3}. This results compared with Turkey’s limits (400 Bq/m{sup 3}) are low, conversely higher compared with WHO’s limits (100 Bq/m{sup 3}).

  17. 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

  18. The sources and fate of (210)Po in the urban air: A review.

    Science.gov (United States)

    Długosz-Lisiecka, Magdalena

    2016-09-01

    The origin of (210)Po activity and its fluctuations in the air are discussed in this paper. In the case of atmospheric aerosol samples, a comparison of the (210)Po/(210)Pb and (210)Bi/(210)Pb activity ratios makes it possible not only to determine aerosol residence times but also to appraise the contribution of the unsupported (210)Po coming from other sources than (222)Rn decay, such as human industrial activities, especially coal combustion. A simple mathematical method makes it possible to observe the seasonal fluctuations of the anthropogenic excess of (210)Po in the urban air. The average doses of (210)Po intake with food (including drinking water) and inhalation of urban aerosols are usually lower than those from (210)Po intake by cigarette smokers and negligible in comparison to total natural radiation exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Reference Atmosphere for Mercury

    Science.gov (United States)

    Killen, Rosemary M.

    2002-01-01

    We propose that Ar-40 measured in the lunar atmosphere and that in Mercury's atmosphere is due to current diffusion into connected pore space within the crust. Higher temperatures at Mercury, along with more rapid loss from the atmosphere will lead to a smaller column abundance of argon at Mercury than at the Moon, given the same crustal abundance of potassium. Because the noble gas abundance in the Hermean atmosphere represents current effusion, it is a direct measure of the crustal potassium abundance. Ar-40 in the atmospheres of the planets is a measure of potassium abundance in the interiors, since Ar-40 is a product of radiogenic decay of K-40 by electron capture with the subsequent emission of a 1.46 eV gamma-ray. Although the Ar-40 in the Earth's atmosphere is expected to have accumulated since the late bombardment, Ar-40 in the atmospheres of Mercury and the Moon is eroded quickly by photoionization and electron impact ionization. Thus, the argon content in the exospheres of the Moon and Mercury is representative of current effusion rather than accumulation over the lifetime of the planet.

  20. Use of radon as tracer for identification of aquifer discharge along the Matinha stream, MG, Brazil; O uso do radonio como tracador para identificacao de descarga de aquiferos ao longo do corrego da Matinha, MG

    Energy Technology Data Exchange (ETDEWEB)

    Chagas, Claudio Jose

    2017-11-01

    Within the framework of 'Nuclear Techniques' is the use of natural and artificial isotopes as tracers for the study of the environment. The use of natural tracers in hydrology is a very useful tool that has been used in several scenarios. One such tracer is the isotope of radon, {sup 222}Rn, a noble gas from natural sources as a consequence of alpha decay of {sup 226}Ra. Radon can be found, to a greater or lesser degree, in all groundwater, as well as in soils and rocks from where it exudes into the atmosphere through spaces arising from fissures and or nanopores present. It can emerge into the water bodies by the leaching of water or other liquids through these interstices. In this research, the {sup 222}Rn gas diluted naturally by the leaching of the water that infiltrated the soils and rocks of the aquifers was used as a tracer in order to identify sections of discharge of these aquifers along the Stream of Matinha. The study area is about 70 km from Belo Horizonte and is in the city of Itauna, MG. The Matinha stream is about 2,200 m in length and is part of the network of tributaries of the water reservoir called Serra Azul, in the Juatuba River Basin, MG. The results presented express the studies that occurred between the second half of 2014 and the first half of 2016, in ten campaigns for water sampling, flow and natural gamma radiation measurements. Water samples were collected near the bottom and very close to the thalweg in the watercourse using syringe and or peristaltic suction pump at low flow to avoid gas leakage. The {sup 222}Rn analyzes were performed in the field during the collections and in the laboratory of the CDTN - Centro de Desenvolvimento da Tecnologia Nuclear, all of which were carried out with the radon detector RAD 7. The flow measurements counted on the use of the fluorescent tracer's technique: rhodamine and fluorescein were used for injection at points upstream and downstream of sections with higher {sup 222}Rn

  1. Use of radon as tracer for identification of aquifer discharge along the Matinha stream, MG, Brazil

    International Nuclear Information System (INIS)

    Chagas, Claudio Jose

    2017-01-01

    Within the framework of 'Nuclear Techniques' is the use of natural and artificial isotopes as tracers for the study of the environment. The use of natural tracers in hydrology is a very useful tool that has been used in several scenarios. One such tracer is the isotope of radon, "2"2"2Rn, a noble gas from natural sources as a consequence of alpha decay of "2"2"6Ra. Radon can be found, to a greater or lesser degree, in all groundwater, as well as in soils and rocks from where it exudes into the atmosphere through spaces arising from fissures and or nanopores present. It can emerge into the water bodies by the leaching of water or other liquids through these interstices. In this research, the "2"2"2Rn gas diluted naturally by the leaching of the water that infiltrated the soils and rocks of the aquifers was used as a tracer in order to identify sections of discharge of these aquifers along the Stream of Matinha. The study area is about 70 km from Belo Horizonte and is in the city of Itauna, MG. The Matinha stream is about 2,200 m in length and is part of the network of tributaries of the water reservoir called Serra Azul, in the Juatuba River Basin, MG. The results presented express the studies that occurred between the second half of 2014 and the first half of 2016, in ten campaigns for water sampling, flow and natural gamma radiation measurements. Water samples were collected near the bottom and very close to the thalweg in the watercourse using syringe and or peristaltic suction pump at low flow to avoid gas leakage. The "2"2"2Rn analyzes were performed in the field during the collections and in the laboratory of the CDTN - Centro de Desenvolvimento da Tecnologia Nuclear, all of which were carried out with the radon detector RAD 7. The flow measurements counted on the use of the fluorescent tracer's technique: rhodamine and fluorescein were used for injection at points upstream and downstream of sections with higher "2"2"2Rn activities. The fluorimeter used to

  2. Charm Decays at BABAR

    International Nuclear Information System (INIS)

    Charles, M.

    2004-01-01

    The results of several studies of charmed mesons and baryons at BABAR are presented. First, searches for the rare decays D 0 → l + l - are presented and new upper limits on these processes are established. Second, a measurement of the branching fraction of the isospin-violating hadronic decay D* s (2112) + → D s + π 0 relative to the radiative decay D* s (2112) + → D s + γ is made. Third, the decays of D* sJ (2317) + and D sJ (2460) + mesons are studied and ratios of branching fractions are measured. Fourth, Cabibbo-suppressed decays of the Λ c + are examined and their branching fractions measured relative to Cabibbo-allowed modes. Fifth, the Χ c 0 is studied through its decays to Χ - π + and (Omega) - K + ; in addition to measuring the ratio of branching fractions for Χ c 0 produced from the c(bar c) continuum, the uncorrected momentum spectrum is measured, providing clear confirmation of Χ c 0 production in B decays

  3. Iconic decay in schizophrenia.

    Science.gov (United States)

    Hahn, Britta; Kappenman, Emily S; Robinson, Benjamin M; Fuller, Rebecca L; Luck, Steven J; Gold, James M

    2011-09-01

    Working memory impairment is considered a core deficit in schizophrenia, but the precise nature of this deficit has not been determined. Multiple lines of evidence implicate deficits at the encoding stage. During encoding, information is held in a precategorical sensory store termed iconic memory, a literal image of the stimulus with high capacity but rapid decay. Pathologically increased iconic decay could reduce the number of items that can be transferred into working memory before the information is lost and could thus contribute to the working memory deficit seen in the illness. The current study used a partial report procedure to test the hypothesis that patients with schizophrenia (n = 37) display faster iconic memory decay than matched healthy control participants (n = 28). Six letters, arranged in a circle, were presented for 50 ms. Following a variable delay of 0-1000 ms, a central arrow cue indicated the item to be reported. In both patients and control subjects, recall accuracy decreased with increasing cue delay, reflecting decay of the iconic representation of the stimulus array. Patients displayed impaired memory performance across all cue delays, consistent with an impairment in working memory, but the rate of iconic memory decay did not differ between patients and controls. This provides clear evidence against faster loss of iconic memory representations in schizophrenia, ruling out iconic decay as an underlying source of the working memory impairment in this population. Thus, iconic decay rate can be added to a growing list of unimpaired cognitive building blocks in schizophrenia.

  4. Weak radiative hyperon decays

    International Nuclear Information System (INIS)

    Roberts, B.L.; Booth, E.C.; Gall, K.P.; McIntyre, E.K.; Miller, J.P.; Whitehouse, D.A.; Bassalleck, B.; Hall, J.R.; Larson, K.D.; Wolfe, D.M.; Fickinger, W.J.; Robinson, D.K.; Hallin, A.L.; Hasinoff, M.D.; Measday, D.F.; Noble, A.J.; Waltham, C.E.; Hessey, N.P.; Lowe, J.; Horvath, D.; Salomon, M.

    1990-01-01

    New measurements of the Σ + and Λ weak radiative decays are discussed. The hyperons were produced at rest by the reaction K - p → Yπ where Y = Σ + or Λ. The monoenergetic pion was used to tag the hyperon production, and the branching ratios were determined from the relative amplitudes of Σ + → pγ to Σ + → pπ 0 and Λ → nγ to Λ → nπ 0 . The photons from weak radiative decays and from π 0 decays were detected with modular NaI arrays. (orig.)

  5. SYMPOSIUM: Rare decays

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Late last year, a symposium entitled 'Rare Decays' attracted 115 participants to a hotel in Vancouver, Canada. These participants were particle physicists interested in checking conventional selection rules to look for clues of possible new behaviour outside today's accepted 'Standard Model'. For physicists, 'rare decays' include processes that have so far not been seen, explicitly forbidden by the rules of the Standard Model, or processes highly suppressed because the decay is dominated by an easier route, or includes processes resulting from multiple transitions

  6. Heavy neutrino decay at SHALON

    Directory of Open Access Journals (Sweden)

    Sinitsyna V.Y.

    2013-06-01

    Full Text Available The SHALON Cherenkov telescope has recorded over 2 × 106 extensive air showers during the past 17 years. The analysis of the signal at different zenith angles has included observations from the sub-horizontal direction Θ = 97° This inclination defines an Earth skimming trajectory with 7 km of air and around 1000 km of rock in front of the telescope. During a period of 324 hours of observation, after a cut of shower-like events that may be caused by chaotic sky flashes or reflections on the snow of vertical showers, we have detected 5 air showers of TeV energies. We argue that these events may be caused by the decay of a long-lived penetrating particle entering the atmosphere from the ground and decaying in front of the telescope. We show that this particle can it not be a muon or a tau lepton. As a possible explanation, we discuss two scenarios with an unstable neutrino of mass m ≈ 0.5 GeV and cτ ≈ 30 m. Remarkably, one of these models has been recently proposed to explain an excess of electron-like neutrino events at MiniBooNE.

  7. Phenomenology of atmospheric neutrinos

    Directory of Open Access Journals (Sweden)

    Fedynitch Anatoli

    2016-01-01

    Full Text Available The detection of astrophysical neutrinos, certainly a break-through result, introduced new experimental challenges and fundamental questions about acceleration mechanisms of cosmic rays. On one hand IceCube succeeded in finding an unambiguous proof for the existence of a diffuse astrophysical neutrino flux, on the other hand the precise determination of its spectral index and normalization requires a better knowledge about the atmospheric background at hundreds of TeV and PeV energies. Atmospheric neutrinos in this energy range originate mostly from decays of heavy-flavor mesons, which production in the phase space relevant for prompt leptons is uncertain. Current accelerator-based experiments are limited by detector acceptance and not so much by the collision energy. This paper recaps phenomenological aspects of atmospheric leptons and calculation methods, linking recent progress in flux predictions with particle physics at colliders, in particular the Large Hadron Collider.

  8. Teleportation via decay

    Indian Academy of Sciences (India)

    therefore normally plays a negative role in quantum information processing [1]. ... of a decay be used in a fruitful way for quantum information process- ing? ..... The model independent portions of the analysis of communication through a noisy.

  9. Decay of Hoyle state

    Indian Academy of Sciences (India)

    2014-11-02

    Nov 2, 2014 ... T K RANA, C BHATTACHARYA, S KUNDU, ... of various direct 3α decay mechanisms of the Hoyle state. ... Pramana – J. Phys., Vol. ... FMD predicts a compact triangle shape and LEFT predicts a bent arm chain structure,.

  10. RARE KAON DECAYS

    International Nuclear Information System (INIS)

    LITTENBERG, L.

    2005-01-01

    Lepton flavor violation (LFV) experiments have probed sensitivities corresponding to mass scales of well over 100 TeV, making life difficult for models predicting accessible LFV in kaon decay and discouraging new dedicated experiments of this type

  11. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2012-10-06

    Oct 6, 2012 ... Anyhow, the 'multi-isotope' ansatz is needed to compensate for matrix element ... The neccessary half-life requirement to touch this ... site energy depositions (like double beta decay) and multiple site interactions (most of.

  12. Cavities/Tooth Decay

    Science.gov (United States)

    ... milk, ice cream, honey, sugar, soda, dried fruit, cake, cookies, hard candy and mints, dry cereal, and ... teeth can wear down and gums may recede, making teeth more vulnerable to root decay. Older adults ...

  13. Inflaton decay in supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Endo, M.; Takahashi, F. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yanagida, T.T. [Tokyo Univ. (Japan). Dept. of Physics]|[Tokyo Univ. (Japan). Research Center for the Early Universe

    2007-06-15

    We discuss inflaton decay in supergravity, taking account of the gravitational effects. It is shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the supergravity. Through these processes, the inflaton generically decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. We derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos. Furthermore, the inflaton naturally decays into the visible sector via the top Yukawa coupling and SU(3){sub C} gauge interactions. (orig.)

  14. Inflaton decay in supergravity

    International Nuclear Information System (INIS)

    Endo, M.; Takahashi, F.; Yanagida, T.T.; Tokyo Univ.

    2007-06-01

    We discuss inflaton decay in supergravity, taking account of the gravitational effects. It is shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the supergravity. Through these processes, the inflaton generically decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. We derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos. Furthermore, the inflaton naturally decays into the visible sector via the top Yukawa coupling and SU(3) C gauge interactions. (orig.)

  15. Double beta decay: experiments

    International Nuclear Information System (INIS)

    Fiorini, Ettore

    2006-01-01

    The results obtained so far and those of the running experiments on neutrinoless double beta decay are reviewed. The plans for second generation experiments, the techniques to be adopted and the expected sensitivities are compared and discussed

  16. Streamer chamber: pion decay

    CERN Multimedia

    1992-01-01

    The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

  17. Aspects of B decays

    Energy Technology Data Exchange (ETDEWEB)

    Faller, Sven

    2011-03-04

    B-meson decays are a good probe for testing the flavour sector of the standard model of particle physics. The standard model describes at present all experimental data satisfactorily, although some ''tensions'' exist, i.e. two to three sigma deviations from the predictions, in particular in B decays. The arguments against the standard model are thus purely theoretical. These tensions between experimental data and theoretical predictions provide an extension of the standard model by new physics contributions. Within the flavour sector main theoretical uncertainties are related to the hadronic matrix elements. For exclusive semileptonic anti B {yields} D{sup (*)}l anti {nu} decays QCD sum rule techniques, which are suitable for studying hadronic matrix elements, however, with substantial, but estimable hadronic uncertainties, are used. The exploration of new physics effects in B-meson decays is done in an twofold way. In exclusive semileptonic anti B {yields} D{sup (*)}l anti {nu} decays the effect of additional right-handed vector as well as left- and right-handed scalar and tensor hadronic current structures in the decay rates and the form factors are studied at the non-recoil point. As a second approach one studied the non-leptonic B{sup 0}{sub s}{yields}J/{psi}{phi} and B{sup 0}{yields}J/{psi}K{sub S,L} decays discussing CP violating effects in the time-dependent decay amplitudes by considering new physics phase in the B{sup 0}- anti B{sup 0} mixing phase. (orig.)

  18. Tau decays into kaons

    International Nuclear Information System (INIS)

    Finkemeier, M.; Mirkes, E.

    1995-04-01

    Predictions for semi-leptonic decay rates of the τ lepton into two meson final states and three meson final states are derived. The hadronic matrix elements are expressed in terms of form factors, which can be predicted by chiral Lagrangians supplemented by informations about all possible low-lying resonances in the different channels. Isospin symmetry relations among the different final states are carefully taken into account. The calculated brancing ratios are compared with measured decay rates where data are available

  19. Iconic Decay in Schizophrenia

    OpenAIRE

    Hahn, Britta; Kappenman, Emily S.; Robinson, Benjamin M.; Fuller, Rebecca L.; Luck, Steven J.; Gold, James M.

    2010-01-01

    Working memory impairment is considered a core deficit in schizophrenia, but the precise nature of this deficit has not been determined. Multiple lines of evidence implicate deficits at the encoding stage. During encoding, information is held in a precategorical sensory store termed iconic memory, a literal image of the stimulus with high capacity but rapid decay. Pathologically increased iconic decay could reduce the number of items that can be transferred into working memory before the info...

  20. Annihilation decays of bottomonium

    International Nuclear Information System (INIS)

    Monteiro, Antony Prakash; Bhat, Manjunath; D'Souza, Praveen P.; Vijaya Kumar, K.B.

    2016-01-01

    The bound state of a bottom quark b and its anti quark b-bar known as bottomonium was first seen in the spectrum of μμ"- pairs produced in 400 GeV proton-nucleus collisions at Fermilab. It was discovered as spin triplet states ϒ(1S), ϒ(2S) and ϒ(3S) by E288 collaboration at Fermilab. We have calculated annihilation decay widths of bottomonium states. The calculated decay widths are presented

  1. Rare psi decays

    International Nuclear Information System (INIS)

    Partridge, R.

    1986-01-01

    Slightly more than ten years have passed since the psi was discovered, yet the study of psi decays continues to be an active and fruitful area of research. One reason for such longevity is that each successive experiment has increased their sensitivity over previous experiments either by improving detection efficiency or by increasing statistics. This has allowed the observation and, in some cases, detailed studies of rare psi decays. Branching ratios of ≅10-/sup 4/ are now routinely studied, while certain decay channels are beginning to show interesting effects at the 10-/sup 5/ level. Future experiments at the Beijing Electron Positron Collider (BEPC) have the potential for increasing sensitivities by one or two orders of magnitude, thus enabling many interesting studies impossible with current data samples. The author first examines the extent to which psi decays can be used to study electroweak phenomena. The remainder of this work is devoted to the more traditional task of using the psi to study quarks, gluons, and the properties of the strong interaction. Of particular interest is the study of radioactive psi decays, where a number of new particles have been discovered. Recent results regarding two of these particles, the θ(1700) and iota(1450), are discussed, as well as a study of the quark content of the eta and eta' using decays of the psi to vector-pseudoscalar final states

  2. Decays of supernova neutrinos

    International Nuclear Information System (INIS)

    Lindner, Manfred; Ohlsson, Tommy; Winter, Walter

    2002-01-01

    Supernova neutrinos could be well-suited for probing neutrino decay, since decay may be observed even for very small decay rates or coupling constants. We will introduce an effective operator framework for the combined description of neutrino decay and neutrino oscillations for supernova neutrinos, which can especially take into account two properties: one is the radially symmetric neutrino flux, allowing a decay product to be re-directed towards the observer even if the parent neutrino had a different original direction of propagation. The other is decoherence because of the long baselines for coherently produced neutrinos. We will demonstrate how to use this effective theory to calculate the time-dependent fluxes at the detector. In addition, we will show the implications of a Majoron-like decay model. As a result, we will demonstrate that for certain parameter values one may observe some effects which could also mimic signals similar to the ones expected from supernova models, making it in general harder to separate neutrino and supernova properties

  3. Rare and forbidden decays

    CERN Document Server

    Trampetic, Josip

    2002-01-01

    In these lectures I first cover radiative and semileptonic B decays, including the QCD corrections for the quark subprocesses. The exclusive modes and the evaluation of the hadronic matrix elements, i.e. the relevant hadronic form factors, are the second step. Small effects due to the long-distance, spectator contributions, etc. are discussed next. The second section we started with non-leptonic decays, typically $B \\to \\pi\\pi, K\\pi, \\rho\\pi,...$ We describe in more detail our prediction for decays dominated by the $b\\to s \\eta_c$ transition. Reports on the most recent experimental results are given at the end of each subsection. In the second part of the lectures I discuss decays forbidden by the Lorentz and gauge invariance, and due to the violation of the angular moment conservation, generally called the Standard Model-forbiden decays. However, the non-commutative QED and/or non-commutative Standard Model (NCSM), developed in a series of works in the last few years allow some of those decay modes. These ar...

  4. 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

  5. Radioactive safety analysis and assessment of waste rock pile site in uranium tailings

    International Nuclear Information System (INIS)

    Liu Changrong; Liu Zehua; Wang Zhiyong; Zhou Xinghuo

    2007-01-01

    Based on theoretical calculation and in-situ test results, distribution and emissions of radioactive nuclides of uranium tailings impoundment and waste rock pile sites are analyzed in this paper. It is pointed out that 222 Rn is the main nuclide of uranium tailings impoundment and waste rock pile site. Also 222 Rn is the main source term of public dose. 222 Rn concentrations in the atmospheric environment around and individual dose to Rn gradually decrease with increasing distances to uranium tailings impoundment and waste rock pile site. Based on in-situ tests on five uranium tailings impoundment and waste rock pile sites, a decisive method and safety protection distance are presented, which can be used to guide the validation and design of radioactive safety protection in uranium tailings impoundment and waste rock pile sites. (authors)

  6. Atmospheric contamination

    International Nuclear Information System (INIS)

    Gruetter, Juerg

    1997-01-01

    It is about the levels of contamination in center America, the population's perception on the problem, effects of the atmospheric contamination, effects in the environment, causes of the atmospheric contamination, possibilities to reduce the atmospheric contamination and list of Roeco Swisscontac in atmospheric contamination

  7. Neutron decay, semileptonic hyperon decay and the Cabibbo model

    International Nuclear Information System (INIS)

    Siebert, H.W.

    1989-01-01

    The decay rates and formfactor ratios of neutron decay and semileptonic hyperon decays are compared in the framework of the Cabibbo model. The results indicate SU(3) symmetry breaking. The Kobayashi-Maskawa matrix element V us determined from these decays is in good agreement with the value determined from K→πeν decays, and with unitarity of the KM-matrix. (orig.)

  8. CP violation in B decay

    OpenAIRE

    Yamamoto, Hitoshi

    2001-01-01

    We review the physics of CP violation in B decays. After introducing the CKM matrix and how it causes CP violation, we cover three types of CP violation that can occur in B decays: CP violation in mixing, CP violation by mixing-decay interference, and CP violation in decay.

  9. Radioactive decay and labeled compounds

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This chapter on radioactive decay and labeled compounds has numerous intext equations and worked, sample problems. Topics covered include the following: terms and mathematics of radioactive decay; examples of calculations; graphs of decay equations; radioactivity or activity; activity measurements; activity decay; half-life determinations; labeled compounds. A 20 problem set is also included. 1 ref., 4 figs., 1 tab

  10. Strength loss in decayed wood

    Science.gov (United States)

    Rebecca E. Ibach; Patricia K. Lebow

    2014-01-01

    Wood is a durable engineering material when used in an appropriate manner, but it is susceptible to biological decay when a log, sawn product, or final product is not stored, handled, or designed properly. Even before the biological decay of wood becomes visually apparent, the decay can cause the wood to become structurally unsound. The progression of decay to that...

  11. Estimation of North American population doses resulting from radon-222 release in western United States: methodology

    International Nuclear Information System (INIS)

    Fields, D.E.; Travis, C.C.; Watson, A.P.; McDowell-Boyer, L.M.

    1979-12-01

    The report represents a compilation of computer codes used to estimate potential human exposures and inhalation doses due to unit releases of 222 Rn from uranium milling sites in western United States. The populations considered for potential exposure to risk from 222 Rn and associated daughters are the inhabitants of North America between 20 0 and 60 0 North latitude. The primary function of these codes is to integrate spatially atmospheric radionuclide concentrations with current population data for the geographic area under consideration. It is expected that these codes will be of assistance to anyone interested in assessing nuclear or nonnuclear population exposures over large geographic areas

  12. Assessment of radon build up pattern in a closed room with minimal ventilation disturbance

    International Nuclear Information System (INIS)

    Singh, M.K.; Patnaik, R.L.; Jha, V.N.; Ravi, P.M.; Tripathi, R.M.

    2016-01-01

    Radon is ubiquitous in nature. The immediate source of Radon is 226 Ra is present in building materials underneath earth due to presence of natural uranium in terrestrial region. 222 Ra gas continuously diffused out into room atmosphere through the pores, cracks and fissures if any. The buildup of this 222 Rn is anticipated in a closed room lack of proper ventilation. A study was done to see the build up pattern of radon concentration by two different measurement techniques in a closed room of ESL, Jaduguda. Present paper summarizes the result of buildup study of 222 Rn in a closed room of lab for a period of 3 months

  13. Radon and radium measurement in well water at Curitiba (PR), Brazil

    International Nuclear Information System (INIS)

    Correa, Janine N.; Paschuk, Sergei A.; Perna, Allan F.N.; Kappke, Jaqueline; Claro, Flavio del; Denyak, Valeriy; Schelin, Hugo R.; Rocha, Zildete

    2011-01-01

    This study presents the results of 226 Ra and 222 Rn activity concentration measurements in well water in the city of Curitiba - Parana State of Brazil. Water samples were collected from 31 wells and submitted to the radioactivity measurements in the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR) in cooperation with CDTN-CNEN. Each water sample was submitted to 4 measurements of radon concentration with interval of three days. After two months the same samples were submitted once again to 222 Rn concentration measurements with an objective to evaluate indirectly the amount of 226 Ra contained in water samples. The 222 Rn concentration measurements were performed using AlphaGUARD radon monitor (Genitron Instruments) and 226 Ra concentration was evaluated using the decay curves of 222 Rn. Within few hours after extraction about 70% of water samples from monitored wells presented 222 Rn concentration values above the limit of 11.1 Bq/L recommended by the USEPA. Obtained activity values varied between 1.57 Bq/L - 215.16 Bq/L for radon concentration, and radium concentrations deviated within an interval of 0.61 Bq/L - 6.76 Bq/L. Obtained results showed that the biggest part of 222 Rn found in water samples was not originated from the 226 Ra compounds soluble in water but from gas exhalation by the soil adjacent to the well. The results of present research show the requirement of radioactivity monitoring of water extracted from artesian wells at Curitiba region and indicate the necessity of mitigation procedure development for better control of global alpha radioactivity in drinking water. (author)

  14. Radioisotopes present in building materials of workplaces

    Science.gov (United States)

    Del Claro, F.; Paschuk, S. A.; Corrêa, J. N.; Denyak, V.; Kappke, J.; Perna, A. F. N.; Martins, M. R.; Santos, T. O.; Rocha, Z.; Schelin, H. R.

    2017-11-01

    The isotope 222Rn is responsible for approximately half of the effective annual dose received by the world population. The decay products of 222Rn interacting with the cells of biological tissue of lungs have very high probability to induce cancer. The present survey was focused in the evaluation of activity concentration of 222Rn and other radioisotopes related to the building materials at workplaces at Curitiba - Paraná State. For this purpose, the instant radon detector AlphaGUARD (Saphymo GmbH) was used to measure the average concentrations of 222Rn in building materials, which were also submitted to gamma spectrometry analysis for qualitative and quantitative evaluation of the radionuclides present in samples of sand, mortar, blue crushed stone (Gneissic rock), red crushed stone (Granite), concrete and red bricks. The main radionuclides evaluated by gamma spectrometry in building material samples were 238U/226Ra, 232Th and 40K. These measurements were performed at the Laboratory of Applied Nuclear Physics of the Federal University of Technology - Paraná in collaboration with the Center of Nuclear Technology Development (CDTN - CNEN). The results of the survey present the concentration values of 222Rn related to construction materials in a range from 427±40.52 Bq/m³ to 2053±90.06 Bq/m³. The results of gamma spectroscopy analysis show that specific activity values for the mentioned isotopes are similar to the results indicated by the literature. Nevertheless, the present survey is showing the need of further studies and indicates that building materials can contribute significantly to indoor concentration of 222Rn.

  15. Sigma beta decay

    International Nuclear Information System (INIS)

    Newman, D.E.

    1975-01-01

    Describes an experiment to measure beta decays of the sigma particle. Sigmas produced by stopping a K - beam in a liquid hydrogen target decayed in the following reactions: Kp → Σπ; Σ → Neν. The electron and pion were detected by wire spark chambers in a magnetic spectrometer and by plastic scintillators, and were differentiated by a threshold gas Cherenkov counter. The neutron was detected by liquid scintillation counters. The data (n = 3) shell electrons or the highly excited electrons decay first. Instead, it is suggested that when there are two to five electrons in highly excited states immediately after a heavy ion--atom collision the first transitions to occur will be among highly excited Rydberg states in a cascade down to the 4s, 4p, and 3d-subshells. If one of the long lived states becomes occupied by electrons promoted during the collision or by electrons falling from higher levels, it will not decay until after the valence shell decays. LMM rates calculated to test the methods used are compared to previous works. The mixing coefficients are given in terms of the states 4s4p, 45sp+-, and 5s5p. The applicability of Cooper, Fano, and Prats' discussion of the energies and transition rates of doubly excited states is considered

  16. 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.

  17. Beta and muon decays

    International Nuclear Information System (INIS)

    Galindo, A.; Pascual, P.

    1967-01-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  18. Decay of superdeformed bands

    International Nuclear Information System (INIS)

    Carpenter, M.P.; Khoo, T.L.; Lauritsen, T.

    1995-01-01

    One of the major challenges in the study of superdeformation is to directly connect the large number of superdeformed bands now known to the yrast states. In this way, excitation energies, spins and parities can be assigned to the levels in the second well which is essential to establish the collective and single-particle components of these bands. This paper will review some of the progress which has been made to understand the decay of superdeformed bands using the new arrays including the measurement of the total decay spectrum and the establishment of direct one-step decays from the superdeformed band to the yrast line in 194 Hg. 42 refs., 5 figs

  19. Beta and muon decays

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, A; Pascual, P

    1967-07-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  20. Suppressed Charmed B Decay

    Energy Technology Data Exchange (ETDEWEB)

    Snoek, Hella Leonie [Vrije Univ., Amsterdam (Netherlands)

    2009-06-02

    This thesis describes the measurement of the branching fractions of the suppressed charmed B0 → D*- a0+ decays and the non-resonant B0 → D*- ηπ+ decays in approximately 230 million Υ(4S) → B$\\bar{B}$ events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B0 → D*- a{sub 0}+ decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10-6. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle γ, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle γ can be performed using the decays of neutral B mesons. The B0 → D*- a0+ decay is sensitive to the angle γ and, in comparison to the current decays that are being employed, could significantly

  1. Weak interactions: muon decay

    International Nuclear Information System (INIS)

    Sachs, A.M.; Sirlin, A.

    1975-01-01

    The traditional theory of the dominant mode of muon decay is presented, a survey of the experiments which have measured the observable features of the decay is given, and those things which can be learned about the parameters and nature of the theory from the experimental results are indicated. The following aspects of the theory of muon decay are presented first: general four-fermion theory, two-component theory of the neutrino, V--A theory, two-component and V--A theories vs general four-fermion theory, intermediate-boson hypothesis, radiative corrections, radiative corrections in the intermediate-boson theory, and endpoint singularities and corrections of order α 2 . Experiments on muon lifetime, isotropic electron spectrum, total asymmetry and energy dependence of asymmetry of electrons from polarized muons, and electron polarization are described, and a summary of experimental results is given. 7 figures, 2 tables, 109 references