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The data below are the 'raw' extracts from the documents and/or papers. Please refer to the last column for the reference and obtain the full text if required. Please also let me know if there are any mistakes here. |
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1
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UK,
glass processing
Rare earths in glass polishing compounds Heat treatment and particle size reduction used to condition the rare earth as a glass polishing compound. Dusty conditions can exist at the loading station and during product removal. Significant gamma dose rates exist close to bulk storage. When used as polishing compound, radiological implications not significant due to the small amount used. Rare earths as additive in special glasses Rare earth concentrate is added as a process involves the vacuum coating of optical components to provide a non-reflecting surface. Amounts of thorium are small but - contamination minor component in certain specific glasses. Dusty conditions and gamma dose rates near bulk storage can exist. Thorium fluoride as a lens coating The process involves the vacuum coating of optical components to provide a non-reflecting surface. Amounts of Th are small - but a vacuum chamber may become contaminated. Typical concentrations in thorium fluoride (Bq/g) Th-232 3600, Ra-228 1800. Estimated typical doses for a person working with thorium fluoride 3.7 mSv/year. |
H-01
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2
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USA,
computer monitor screens Elevated readings registered on regular old computer monitor screens. Many glass manufacturers use potash, or potassium carbonate, as an alkali ingredient in the glass mixture. Alkali serves to lower the melting point of the silica or whatever they use as the main ingredient. The incresed readings are caused by K-40. |
R-04
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3
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Glass manufacturing industry Raw materials used in the process all show typical background levels (< 2 to 5 ppm U and Th) but the furnace "ash" from the process is enhanced in Ra-226 (about 3 Bq/g), Ra-228 (about 0.5 Bq/g) and the more volatile radionuclides Pb-210 and Po-210 (about 1 Bq/g). The U (10 ppm) and Th (4 ppm) are also marginally enhanced. |
R-09
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4
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Glass manufacturing industry A specialty glass company added depleted uranium (DU) to a variety of glass products to provide either a specific colour or absorption property. Some of the glass was 100 microGy/h on contact (measured by an air ion chamber). 75 kg/year of depleted uranium was used in manufacturing. |
R-10
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