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Radon-based technique for the analysis of atmospheric stability : a case study from Central Poland

Podstawczyńska A., Chambers S. D.

Nukleonika

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2018

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Vol. 63, No. 2

47--54

EN

An economical and easy-to-implement technique is outlined by which the mean nocturnal atmospheric mixing state (“stability”) can be assessed over a broad (city-scale) heterogeneous region solely based on near- -surface (2 m above ground level [a.g.l.]) observations of the passive tracer radon-222. The results presented here are mainly based on summer data of hourly meteorological and radon observations near Łodź, Central Poland, from 4 years (2008–2011). Behaviour of the near-surface wind speed and vertical temperature gradient (the primary controls of the nocturnal atmospheric mixing state), as well as the urban heat island intensity, are investigated within each of the four radon-based nocturnal stability categories derived for this study (least stable, weakly stable, moderately stable, and stable). On average, the most (least) stable nights were characterized by vertical temperature gradient of 1.1 (0.5)⁰C·m-1, wind speed of ~0.4 (~1.0) m·s-1, and urban heat island intensity of 4.5 (0.5)⁰C. For sites more than 20 km inland from the coast, where soils are not completely saturated or frozen, radon-based nocturnal stability classification can significantly enhance and simplify a range of environmental research applications (e.g. urban climate studies, urban pollution studies, regulatory dispersion modelling, and evaluating the performance of regional climate and pollution models).

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Exhalation rate of radon-222 from concrete and cement mortar

Perna A. F. N., Paschuk S.A., Corrêa J. N., Narloch D. C., Barreto R. C., Del Claro F., Denyak V.

Nukleonika

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2018

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Vol. 63, No. 3

65--72

EN

The main sources of radon in the air of dwellings are soil, building materials, and groundwater. This study aimed to determine the exhalation rate of 222Rn from samples made of concrete and cement mortars, as well as to evaluate by means of gamma spectrometry the hazard indexes associated with other radionuclides present in the studied samples of building materials. The results obtained allowed the comparison of the exhalation rate of radon using theoretical calculations based on one-dimensional and three-dimensional models. Measurements of the activity concentration of radon in air was performed by AlphaGuard radon detector. Furthermore, obtained results were compared with the measurements performed inside the concrete test cells. These test cells were built with the aim of simulating a dwelling in small dimensions and to evaluate indoor radon activity associated with concrete. Consequently, the obtained results of radon exhalation rate, in becquerel per meter squared per hour, for the concrete was 2.55 ± 0.03 Bq·h–1·m–2 for the 1D model and 0.461 ± 0.008 Bq·h–1·m–2 for the 3D model. The exhalation rate of radon, for the cement mortar was 1.58 ± 0.03 Bq·h–1·m–2 for the 1D model and 0.439 ± 0.011 Bq·h–1·m–2 for the 3D model. The indoor concentration of 222Rn from the test cell was 112 ± 9 Bq/m3 . These values were below the limit of 300 Bq/m3 recommended by the International Commission on Radiological Protection (ICRP) and <148 Bq/m3 , the limit recommended by the US Environmental Protection Agency (US EPA). Even so, these values should be the subject of concern since that activity is related only to the contribution of concrete walls.

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Thorium nuclear fuel - thoron aspect

Zagórski Z. P., Głuszewski W.

Nukleonika

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2010

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Vol. 55, No. 3

407-408

EN

The communication reports a serious complication connected with preparation, storage and transportation of fuel for thorium and uranium/thorium nuclear reactors. Whereas uranium fuel of any degree of enrichment is free from radium, which produces radon-222, thorium itself produces thoron (radon-220). Measurement of thoron by a routine ionization-chamber device around a small sample of 2 g thorium dioxide shows already the health endangerment situation. The presence of thoron is also confirmed by a typical solid state dosemeter (polymer CR-39), exposed to the air around ThO2 and etched afterwards with warm NaOH solution. The unavoidable presence of thoron can cause increase of price of production of nuclear fuel, demanding special approach to the method of manufacture.

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Intercomparison of radon CR-39 detector systems conducted in CLOR's calibration chamber

Mamont-Cieśla K., Stawarz O., Karpińska M., Kapała J., Kozak K., Grządziel D., Chałupnik S., Chmielewska I., Olszewski J., Przylibski T. A., Żebrowski A.

Nukleonika

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2010

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Vol. 55, No. 4

589-593

EN

Six radon laboratories, which perform indoor radon measurements to jointly investigate temporal variations of radon concentration in houses in a couple of regions in Poland, participated in the intercomparison exercise. There are involved three commercially available Hungarian RadoSys systems and four own laboratory methods. All of them are based on the etched-track CR-39 detectors. The intercomparison was conducted in a calibration laboratory of the Central Laboratory for Radiological Protection (CLOR), Warsaw, Poland, accredited by the Polish Center for Accreditation (previously AP 101, at present AP 057). Comparison measurements were performed during three expositions in the CLOR’s radon calibration chamber under controlled normal climatic conditions and steady radon concentration. The results were referred to the value of the radon concentration determined by AlphaGUARD monitor traceable to the primary 222Rn standard in Physikalisch-Technische Bundesanstalt (PTB), Braunchweig, Germany. The mean performance ratio defined as a ratio of the reference to participant’s result range from 0.88 to 1.31.

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Dose assessment and radioactivity of the mineral water resources of Dimeh springs in the Chaharmahal and Bakhtiari Province, Iran

Shahbazi-Gahrouei D., Saeb M.

Nukleonika

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2008

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Vol. 53, No. 1

31-34

EN

. One of the main sources of public exposure from natural radioactivity is radium and radon and its short lived decay products. The aim of this study is focused on determining the concentration of mentioned radionuclides in the mineral water resources in one of the highest altitude regions (Zagros Mountains), the Chaharmahal and Bakhtiari province, in South-West Iran, namely the Dimeh springs. Eighty drinking spring water samples were taken from the Dimeh springs (ten samples for each spring) to determine radium-226 (226Ra) and radon-222 (222Rn) concentrations using the emanation method and a liquid scintillation counting method, respectively. The results of this study showed that the effective dose from the consumption of drinking water of Dimeh springs (6.4 žSv/y) is not comparable to the other annual effective dose such as inhalation of radon and its products in cosmic and terrestrial rays published by one of the authors previously. Also, the annual effective dose measured here is much lower than the worldwide mean value 0.45 mSv reported by USCEAR, 2000 and is also low enough and below the proposed limits in other countries and this is the reason why this sources of water may be considered as safe drinking water in the region.