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Aurelian, F.; Popescu, M.; Georgescu, D.
Societe Francaise de Radioprotection - SFRP, BP72, 92263 Fontenay-aux-Roses Cedex (France)2006
Societe Francaise de Radioprotection - SFRP, BP72, 92263 Fontenay-aux-Roses Cedex (France)2006
AbstractAbstract
[en] The paper presents a case study concerning the impact on environment and population of a Pilot Station, which was used between 1970 and 1996 to obtain mono-mineral concentrates (ilmenite, zircon, garnet, rutile, monazite) by processing alluvial and seashore sands. The processing technological flow sheet was constituted only of physical separation processes, where were operating equipments such as shaking tables, electric and magnetic separators, attrition equipments, etc. The paper is structured on three levels and presents: - A brief description of the Pilot Station activity, sand types processed and its physical, chemical and mineralogic characteristics. The obtained products were: garnets with 10 ppm uranium and 60 ppm thorium, ilmenite with 10 ppm uranium and 20 ppm thorium, zircon with 450 ppm uranium and 750 ppm thorium and monazite with 3,000 ppm uranium and 20,000 ppm thorium. The sterile accumulated during the Pilot Station functioning time is also characterized. - The impact of the Pilot Station activity on environment (soil, air). The contamination sources are identified and characterized. The only one contamination pathway is represented by 'radioactive dust' resulted from the sands processing activity. The contamination processes are explained and justified. The contaminated soil surface was investigated through: gamma rate doses determination (at the surface and on a depth o f up to 40 cm), measurement of Rn 222 + Rn 220 concentration at one meter distance from the surface and for 40 cm soil depth, analysis of uranium, radium and thorium for samples collected from a soil depth ranging between 10 and 40 cm. There were elaborated maps showing gamma rate doses distribution and the specific activity for the surface as well as for the different soil depths. It was established the contamination level and its value was compared to the ones stipulated by Romanian Nuclear Authority norms, namely 0.2 Bq/g for the specific activity (Ra 226 + Th 232) and 0.3 μSv/h for gamma rate dose at one meter distance from soil surface. - The assessment of the impact on persons from critical group of population through a scenario re-created for 280 hours spent nearby the contaminated soil surface. The supplementary effective doses were assessed after the determination of the effective doses generated by the local background (ET-background = 1.324 mSv/year).The value of the supplementary effective dose value received by a person through all the transportation pathways under the frame of the re-creation scenario is 0.18 mSv/year. The paper represents a part of documentation for Pilot Station closure, decommissioning and environmental rehabilitation. (authors)
Primary Subject
Secondary Subject
Source
2006; 1 p; Second European IRPA congress on radiation protection - Radiation protection: from knowledge to action; Paris (France); 15-19 May 2006
Record Type
Miscellaneous
Literature Type
Conference
Report Number
Country of publication
ACTINIDE NUCLEI, ACTINIDES, ALKALINE EARTH ISOTOPES, ALPHA DECAY RADIOISOTOPES, CARBON 14 DECAY RADIOISOTOPES, DAYS LIVING RADIOISOTOPES, DOSES, ELECTROMAGNETIC RADIATION, ELEMENTS, EVEN-EVEN NUCLEI, HEAVY ION DECAY RADIOISOTOPES, HEAVY NUCLEI, IONIZING RADIATIONS, ISOTOPES, MATERIALS, METALS, MINERALS, NUCLEI, OXIDE MINERALS, PHOSPHATE MINERALS, RADIATIONS, RADIOACTIVE MATERIALS, RADIOACTIVE MINERALS, RADIOISOTOPES, RADIUM ISOTOPES, RADON ISOTOPES, SECONDS LIVING RADIOISOTOPES, SILICATE MINERALS, SPONTANEOUS FISSION RADIOISOTOPES, THORIUM ISOTOPES, THORIUM MINERALS, YEARS LIVING RADIOISOTOPES
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