原子能院周围环境土壤和生物样中^(241)Am量的调查研究

INVESTIGATION OF^(241)Am IN ENVIRONMENTAL SOIL AND SOME BIOLOGI CAL SPECIMENS AROUND CHINA INSTITUTE OF ATOMIC ENERGY

报道了中国原子能科学研究院内４６—戊，５０３，１４６工号附近及院周围１０ｋｍ范围内土壤中（２４１）￣Ａｍ含量；测定了院周围农村所产１２种农作物中（２４１）￣Ａｍ浓度以及（２４１）￣Ａｍ从土壤经由植物根系向植物体的转移系数。调查表明，院内这三个处理超钚核素工号的正常运行没有对周围环境造成可觉察的（２４１）￣Ａｍ污染。院周围１０ｋｍ范围内土壤中（２４１）￣Ａｍ浓度为４３±１４ｍＢｑ·ｋｇ￣（－１），属全球性放射性落下灰所致环境本底水平。院周围农村所产作物中（２４１）￣Ａｍ的含量范围为０．０４２－０．９４ｍＢｑ·ｋｇ￣（－１）（鲜重）；（２４１）￣Ａｍ从土壤向这些作物的转移系数为６．２×ｌ０￣（－４）—５．Ｉ×Ｉ０￣（－３）。

The contents of(24 1)￣Am in soil , some species of vegetable and corn are measured. These specimensare collected in the vicinity to fuel reprocessing laboratory,(24 1)￣ Am-Be neutron source producing labora-tories of CIAE and.from villeages around CIAE , respectively. Results investigated show that no observ-able environmental contamination of(241)￣ Am could be detected during all the three laboratories in CLAEinvolved in handling(241)￣ Am in normal operation. In the area within 1 0 km from CIAE , the averageconcentration of(241)￣Am in soil is 43±14 mBq·kg￣(-1)(dry). On this basis, a conclusion could be de-duced that this value is due to the environmental background as a result of worldwide fallout. The con-centration of(241)￣Am in 12 species of vegetable and corn range from 0. 04 to 0. 94 mB·kg￣(-1)(fresh),and the transfer factors of(241)￣Am from soil to plant by root uptake range from 6.2×10￣(-4)to 5.1×10￣(-3). The distribution of(241)￣Am in soil profiles showed that more than 74%of deposited(241)￣Am has re-mained in the uppermost layer of soil of 0 5cm onsite.