新疆伊犁燃煤灰放射性核素水平与富集因子分析

为了探明新疆伊犁家用燃煤灰放射性核素比活度本底值,分析了新疆伊犁河谷各矿区的48个有效燃煤炉灰样。分析结果表明:燃煤灰238 U、232 Th、226 Ra和40 K比活度范围分别为11.5~682.0、7.5~88.7、11.4~926.0、LLD~372.0Bg/kg;比活度均值分别为104.4、37.6、126.7、101.7Bq/kg。计算得到41对燃煤与燃煤炉底灰放射性核素238 U、232 Th、226 Ra、40 K的富集因子为0.1~26.6、3.3~309.2、0.4~284.0和1.7~225.5,238 U、232 Th、226 Ra相对富集因子为0.01~19.97、0.06~77.9和0.02~54.5。研究表明,此次调查的家用燃煤灰放射性核素数据与其它地区和国家数据相比为最小,燃煤与家用燃煤灰的富集因子与文献报道的相似,根据联合国电离辐射效应委员会统计的全球煤及煤灰背景值资料,此次数据均在正常值范围内。

Natural Radionuclides Concentration and Enrichment Factors in Burned-Coal Domestic Bottom Ash in Ili Valley of Xinjiang

Due to measuring the background value of specific activity of radionuclides (238 U, 232 Th,226 Ra,40 K),48 collected samples of bottom ash of coal in the coalfields were analyzed by Gamma-ray spectrometer at China Nuclear Radiation Protection Research Institute.The results show that the specific activity are 104.4 Bq/kg (238 U),37.6 Bq/kg (232 Th),126.7 Bq/kg (226 Ra)and 101.7 Bq/kg (40 K).The enrichment factors(EF)of the radionuclides in bottom ash relative to the input coal during the combustion process range from 0.1 to 26.6 for 238 U, from 3.3 to 309.2 for 232 Th,from 0.4 to 284.0 for 226 Ra and from 1.7 to 225.5 for 40 K, whereas the relative enrichment factors(REF)are 0.01 to 19.97 (238U),0.06 to 77.9 (232 Th)and 0.02 to 54.5 (226 Ra).The specific activity of 238 U,226 Ra,232 Th and 40 K present the lowest in bottom ash in Ili Valley of Xinjiang compared with other areas and nations.