【摘 要】
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The Fen complex,including the Sove mines,is located approximately 120 km southwest of Oslo,Norway.Up t0 1927 the Sove mines were used for the mining of iron ore and in 1920 the carbonatite mineral Sov
【机 构】
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Institute for Energy Technology,Health and Safety Department,P.O. Box 40,2027 Kjeller,Norway
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The Fen complex,including the Sove mines,is located approximately 120 km southwest of Oslo,Norway.Up t0 1927 the Sove mines were used for the mining of iron ore and in 1920 the carbonatite mineral Sovite was discovered in the area.This igneous carbonatite mineral contains elevated levels of niobium,uranium,thorium and rare earths.In the period 1951-1965 the Ministry of Industry and Mining started production of Ferroniobium at the Sove mines.During the production process uranium and thorium were concentrated in the slag that was dumped just outside the building where Ferroniobium was produced.Today,the NORM contaminated site consist of a slag heap (2000 1113) and soil mixed with smaller particles from a washing process (500 m3) Most of the tailings area shows dose rates above background for the area (0.1-0.3 μSv/h).The dose rate one meter above ground varies from near background up t0 4 μSv/h.Samples of slag,soil and biota have been measured using gamma spectrometric methods.Neutron activation analysis has been applied to investigate if there is equilibrium between of 238U and 232Th and their progeny.The highest levels of 238U and 232Th measured in the slag are around 50-70 Bq/g.According to Norwegian legislation,the slag and the contaminated soil should be treated ad radioactive waste and deposited in a repository approved for this waste category.The study has been carried out as a joint Polish-Norwegian research project (PORANO) supported by Polish-Norwegian Research Fund.
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