Occupational Exposure to Natural Radiation in Zirconium Refractory Plants in Japan
Occupational Exposure to Natural Radiation in Zirconium Refractory Plants in Japan
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DOI：
10.1097/hp.0b013e31826f55f8
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发表时间：
2013-02
期刊：
影响因子：
2.2
通讯作者：
K. Iwaoka;H. Tabe;Toshikazu Suzuki;H. Yonehara
中科院分区：
文献类型：
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作者：
K. Iwaoka;H. Tabe;Toshikazu Suzuki;H. Yonehara
作者测量了日本锆矿石加工厂原材料、产品和气溶胶中天然放射性核素的环境剂量率和活度浓度，以及不定形耐火材料、定形耐火材料和电铸耐火材料中222 Rn和220 Rn的浓度。对工厂工人的有效剂量进行了估计。耐火材料厂的原材料和产品中238 U系列的放射性浓度高于国际原子能机构安全指南规定的临界值（40 K为10 Bq g−1，所有其他天然放射性核素为1 Bq g−1）。电铸耐火材料厂原材料仓库的环境剂量率为0.75 Sv h−1，在所研究的所有耐火材料厂的所有工作场所中最高。在不定型耐火材料厂的产品输出现场，气溶胶的放射性浓度为0.0015 Bq m−1（238 U）和0.00078 Bq m−3（232 Th），是所有耐火材料厂的所有工作场所中最高的。所有耐火材料厂的所有工作场所的室内222 Rn和220 Rn浓度与日本日常室内场所的浓度几乎相同。工人的最大有效剂量值为430 Sv y−1，低于ICRP第82号出版物规定的干预豁免水平（1，000 Sv y−1）。
AbstractThe authors measured the ambient dose rate and activity concentration of natural radionuclides in raw materials, products, and aerosols on worksites, as well as the 222Rn and 220Rn concentrations in an unshaped refractory, a shaped refractory, and an electrocast refractory plant processing zirconium ore in Japan. Estimations were made of the effective doses to plant workers. The activity concentration of the 238U series in raw materials and products in the refractory plants was higher than the critical values (10 Bq g−1 for 40K and 1 Bq g−1 for all other radionuclides of natural origin) specified in the International Atomic Energy Agency Safety Guide. The ambient dose rate in the raw material warehouse of the electrocast refractory plant was 0.75 Sv h−1, which was the highest among all the worksites at all the refractory plants studied. The activity concentrations of aerosols in the product-output site of the unshaped refractory plant was 0.0015 Bq m−1 for 238U and 0.00078 Bq m−3 for 232Th, which were the highest of all the worksites for all refractory plants. The indoor 222Rn and 220Rn concentrations in all worksites of all the refractory plants were almost the same levels as those in everyday indoor places in Japan. The maximum value of the effective dose to workers was 430 Sv y−1, which was lower than the intervention exemption level (1,000 Sv y−1) specified in ICRP Publication 82.