闽南常用石材天然放射性核素含量分析

Analysing the Content of Natural Radioactive Nuclide in Building Stone Commonly Used in South Fujian

报道闽南常用石材的 33个样品中 ,天然放射性核素含量的分析结果 ,并按照国家有关石材产品分类标准进行划分 .分析结果表明 ,所采集的 33个石材样品 ,有 3个样品的天然放射性核素(2 2 6Ra,2 3 2 Th,40 K)含量异常偏高 ,其放射性比活度大于 C类控制值 ;而其余 30个样品的天然放射性核素含量处于正常本底水平 .所有石材比活度的范围 :2 2 6Ra为 15 .4～ 4 78.0 Bq·kg-1;2 3 2 Th为15 .3～ 6 6 9.3Bq· kg-1,40 K为 15 5～ 2 10 3Bq· kg-1.根据国家标准和建设部行业标准的要求 ,只有 11个石材样品 (其放射性比活度属于 A类控制值 ,内照射指数 MRa和外照射指数 Mr均小于 1)

A report is made on the results of analysis the content of natural radioactive nuclide in 33 samples of building stone commonly used in South Fujian. And a division of them is made in the light of national standard.As indicated by analytical results, 3 out of 33 samples of building stone are very high in natural radioactive nuclide content, with a specific activity greater than control value of class C; while the content of natural radioactivenuclide 226 Ra, 232 Th, and 40 K in the other 30 samples are in normal background level. The specific activity of all the building stone are in the range of 226 Ra,15.4～478.0 Bq·kg -1 , 232 Th,15.3～669.3 Bq·kg -1 , and 40 K, 155～2 103 Bq·kg -1 respectively. In accordance with the demand of national and professional standard, only 11 samples of building stone can be applied to housing development and interior furnish. Their specific activity belong to control value of class A; and their index of internal exposure M Ra and index of external exposure M r are all smaller than 1.