湖南衡阳两煤矿井下222Rn、220Rn水平的调查

本文介绍了在2002年12月～2004年8月期间,对湖南省衡阳市两家煤矿(柏坊矿和松柏矿)井下222Rn、220Rn浓度水平进行调查的结果.调查用222Rn、220Rn被动式累积剂量计按季节分四个阶段进行.调查测量结果表明,四个阶段调查测量两矿井下222Rn、220Rn浓度平均值的范围,222Rn为86～138 Bq/m3,220Rn为51～140 Bq/m3;各工种矿工吸入222Rn、220Rn及其子体所致的年均有效剂量范围为0.23～1.25 mSv,其中220Rn及其子体的剂量贡献约占15%～20%,应引起足够的重视.由于两煤矿都采用了有效的机械通风,井下222Rn、220Rn浓度随季节变化不明显.

SURVEY OF RADON AND THORON CONCENTRATION IN TWO COAL MINES IN HENGYANG CITY OF HUNAN PROVINCE

The survey on the concentrations and distribution of radon and thoron as well as their decay products in two coal mines of Hengyang is given in this paper. The concentrations were measured by using passive integral monitors SSNTD in four periods from Dec. 2002 to Aug. 2004. Both of the coal mines adopted mechanical ventilation and its effect was good. The seasonal variation of radon and thoron concentrations in the mines was not significant, the average radon and thoron concentration in two coal mines ranged from 86 to 138 Bq/m^3 and 41 to 147 Bq/m^3, respectively. The total annual effective doseresuhed from radon, thoron and their decay products to the workers ranged from 0.23 to 1.25 mSv, of which the concentration of thoron and its decay product to the dose accounts for 15% -20% ,thus the dose contribution of thoron cannot be neglected.