Radon levels after restoration of the U-mine disposal site

• Autorzy: Križman M. J. , Rojc J. , Jovanovič P.
• Konferencja: Proceedings of the International Conference "Radon in Environment" 10-14 May 2009, Zakopane Poland
• Języki publikacji: EN

Abstrakty

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.

Słowa kluczowe

EN

uranium mine; restoration; radon exhalation rate; radon concentrations; public exposure

• Wydawca: Institute of Nuclear Chemistry and Technology
• Czasopismo: Nukleonika
• Rocznik: 2010
• Tom: Vol. 55, No. 4
• Strony: 523--527
• Opis fizyczny: Bibliogr. 7 poz., rys.

Twórcy

autor

Križman M. J.

autor

Rojc J.

autor

Jovanovič P.

• M. J. Križman.. Slovenian Nuclear Safety Administration, 16 Železna Str., SI-1000 Ljubljana, Slovenia, Tel.: [phone], Fax: [phone],,

Bibliografia

• 1. IAEA (2002) Monitoring and surveillance of residues from the mining and milling of uranium and thorium. Safety Report Series no. 27. International Atomic Energy Agency, Vienna
• 2. Križman MJ (1996) Planning for environmental restoration of contaminated sites in Slovenia. In: Planning for environmental restoration of radioactively contaminated sites in central and eastern Europe. IAEA--TECDOC-865. IAEA, Vienna. Vol. 2, pp 197–218
• 3. Križman MJ, Peter JE, Rojc J (2009) Study on radon dispersion modes from the U-mine disposal sites at Žirovski Vrh (Slovenia). Radioprotect 44;5:469–474
• 4. Križman M, Stegnar P (1992) Environmental impact of the Žirovski vrh uranium mine on the enhancement of outdoor concentrations. Radiat Prot Dosim 45:723–728
• 5. OECD NEA/IAEA (2002) Environmental remediation ,of uranium product facilities. Organisation for Economic Co-operation and Development, Paris
• 6. Omahen G, Smodiš B, Štrok M (2009) Radioactivity monitoring in the environment of the Žirovski Vrh uranium mine and the environmental impact evaluation. Report IJS-DP-10120. Jožef Stefan Institute, Ljubljana, pp 1–74 (in Slovenian)
• 7.UNSCEAR Report (2000) Natural radioactivity sources. United Nations, New York, pp I:84–156