Wyniki wyszukiwania - BazTech

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Radon levels after restoration of the U-mine disposal site

Križman M. J., Rojc J., Jovanovič P.

Nukleonika

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2010

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Vol. 55, No. 4

523-527

EN

After cessation of the underground mining of uranium ore and production of uranium concentrate at Žirovski Vrh (Slovenia) in the period 1985–1990, two permanent surface disposal sites remained, namely, tailings pile and mine waste rock pile. Both disposal sites were of equal size of 4 hectares and were significant sources of radon. Their final restoration was designed in compliance with the condition of dose constraint for the public and authorized limits for radon exhalation from the remediated piles. In the late summer of 2008, a restoration of the mine waste pile was finished. Radon releases were reduced significantly by constructing an effective radon barrier of well compacted clayey material and a thick complex protective cover layer constructed over it. Radon exhalation rate from the mine waste area was lowered from primary level of 0.7 Bq/m2źs to natural levels (0.01 Bq/m2źs), and consequently, ambient radon levels also decreased on the site and nearby environment. The average radon contribution from the remaining U-mine sources was estimated on the basis of the environmental measurements of radon concentrations; they dropped from initial 7–9 Bq/m3 to approximately 3 Bq/m3. Further reduction of outdoor radon concentrations is expected after 2010, since the restoration of another disposal site will have been completed by the end of this year. Public exposure due to industrial radon after the first phase of restoration satisfactorily meets the dose constraint level of 0.3 mSv/y, since it decreased to less than 0.1 mSv/y.

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Radon w środowisku wód podziemnych i górnej części litosfery

Przylibski T.A.

Wiadomości Chemiczne

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2002

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[Z] 56, 11-12

1003-1033

EN

The article outlines the geochemistry of the only radioactive noble gas, with a special focus on the environments with its highest concentrations - upper lithosphere and groundwaters. The text is based on a review of several hundred works written in the last few decades and on the author’s own research. Special emphasis has been put on the genesis of radon and its migration in these environments, with the dominant role of physical processes, in contrast to almost complete chemical passivity of this element. Another discussed issue is the special significance of the physico-chemical properties of the medium and the centre for radon migration process. What has been also stressed is the significance of the amount and the mode in which radium parent isotopes occur in the environment for the genesis of radon, as well as the importance of half-life, especially that of 222Rn nuclide, for the possibility of its long-distance migration. The description of radon geochemistry provided a basis for the presentation of the most important and the commonest applications of this element as a natural tracer of processes occurring in the lithosphere, hydrosphere and on the borders of these geospheres. Currently conducted research, aimed at getting more profound knowledge of radon geochemistry, will enable its far better and commoner application as a natural radioactive tracer of many processes occurring in the environment. It will also provide a basis for much more effective radiological protection, related to the most important property of this ubiquitous gas - its radioactivity, as well as enable more effective employment of its medicinal (though still disputed) effect on the human organism.

3

Radon in the air in the Millenium of the Polish State Underground Tourist Route in Kłodzko (Lower Silesia)

Przylibski T.A.

Archiwum Ochrony Środowiska

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1998

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Vol. 24, no. 2

33-41

EN

The paper presents results of measurements of average monthly radon concentrations in drifts of the Millenium of the Polish State Underground Tourist Route in Kłodzko. The studies revealed no significant seasonal fluctuations if radon concentration. Constant infux of radon from the geological basement, and most of all from loess-like loams and rhyolite inliers, is compensated by a natural ventilation system Only in the summer, periods of elevated radon concentration in the air of the drifts and chambers of the Route can occur. In individual sections it is possible to measure occasional higher radon concentrations caused by local air flow fluctuations in the drifts. The highest concentration were measured in places with the poorest ventilation - blind drifts ventilated only by backward currents. The average radon concentration measured do not exceed concentrations allowed in apartment buildings. Therefore , in the Route there is no risk of exposure to excessive amounts of radon for personnel and tourists. The results obtained in the Route's drifts may be compared with minimum results expected in basements of houses in the Old Town in Kłodzko. The paper stresses also a role of natural ventilation in protection of underground constructions and apartment building against high radon concentrations in areas of its elevated emanations from the geological basement.

PL

W pracy przedstawiono wyniki pomiarów średnich miesięcznych stężeń radonu w wyrobiskach podziemnej Trasy Turystycznej im. 1000-lecia Państwa Polskiego w Kłodzku. Wykazały one, że nie występują wyraźne sezonowe wahania jego stężeń. Stały dopływ radonu z podłoża a zwłaszcza z glin lessopodobnych oraz wkładek ryolitów , jest rekompensowany przez system naturalnej wentylacji. Jednie w lecie mogą występować okresowe podwyższone koncentracje tego gazu w powietrzu chodników i sal Trasy. Na poszczególnych odcinkach mogą także sporadycznie występować podwyższone stężenia radonu wywołane lokalnymi fluktuacjami przepływu powietrza w wyrobiskach. Najwyższe stężenia notowane są w miejscach najsłabiej wentylowanych - w ślepych wyrobiskach przewietrzanych jedynie prądami wstecznymi. Zarejestrowane średnie poziomy stężeń radonu nie przekraczają stężeń dopuszczalnych w budynkach mieszkalnych . W związku z tym na Trasie nie występują zagrożenia radiologiczne ani dla personelu obsługującego turystów, ani tym bardziej dla samych zwiedzających . Wyniki pomiarów uzyskane w wyrobiskach Trasy można porównać do minimalnych wyników, jakich należy spodziewać się w piwnicach budynków mieszkalnych Starówki Kłodzka. W pracy podkreślono także szczególną rolę naturalnej wentylacji w zabezpieczaniu obiektów podziemnych, a także budynków mieszkalnych przed wysokimi stężeniami radonu w rejonach jego podwyższonych emanacji z podłoża.