黄土包气带中放射性核素迁移的现场试验  

FIELD TEST OF RADIONUCLIDE MIGRATION IN LOESS AERATED ZONE

作　　者：郭择德[1] 王志明[1] 李书绅[1] 姜钢[1] 黄庆春[1] 杨端节[1] 田中忠夫[2] 向井雅之 神山秀雄[2] 

机构地区：[1]中国辐射防护研究院,太原030006 [2]日本原子力研究所

出　　处：《辐射防护》2000年第1期21-31,共11页Radiation Protection

摘　　要：在中国辐射防护研究院野外试验场开展了为期二年的包气带中 3H、6 0 Co、85 Sr和 13 4 Cs的迁移试验 ,在天然条件和人工喷啉条件下共进行了六组试验。通过定期取样和直接测量两种方法测量了示踪核素的浓度分布 ;同时为配合迁移试验 ,同步开展了包气带中水分运移观测在介绍了试验概况之后 ,分析了作为水分运移示踪剂的3 H的试验结果 ,并与野外现场的和实验室的其它研究包气带水分运移的结果相比较 ,令人满意的一致性显示了所建立的包气带水分运移研究方法的可靠性。核素迁移结果表明 ,试验场址的黄土沉积层对所选用的示踪核素具有强烈的吸附滞留作用。经过二年的试验 ,60 Co和13 4Cs的浓度峰无论在天然条件下还是喷淋条件下 ,迁移距离都不超过 1cm;85Sr的浓度峰在喷淋条件下迁移了约 13cm;在天然条件下迁移了约 2 cm。尽管 60 Co和 13 4Cs被黄土强烈吸附滞留 ,但是 ,试验中发现一小部分60 Co和 13 4Cs迁移速度远高于其浓度峰的迁移。试验中还发现 ,在喷淋条件下 ,85Sr在迁移过程中形成具有不同迁移速度的二个浓度峰。A two year field study of radionuclide migration in loess aerated zone was carried out at CIRP's Field Test Site, with total 6 test groups under both natural rainfall and artificial sprinkling conditions, and 3H, 60 Co, 85 Sr and 134 Cs were used as tracers. The concentration distributions in the soil were measured by periodic sampling soil and direct measurement. Meanwhile, systematic water movement observation was performed as support. This paper firstly gives a brief introduction about the test arrangement, then presents the migration results of 3H. The results are compared with the data obtained from other work both in laboratory and in the field. Very good agreement is achieved, which demonstrates the reliability of the developed method. The results show that the loess has very strong adsorption capacity to Co and Cs,and relatively strong adsorption capacity to Sr. For two years, concentration peaks of 60 Co and 134 Cs had no significant movement (less than 1 cm), under natural and artificial sprinkling conditions. Under the artificial sprinkling condition, peak of 85 Sr moved about 13 cm in two years, while less than 2 cm under the natural rainfall condition. Though the loess medium has very strong adsorption to 60 Co and 134 Cs, a small fraction of each radionuclides moved much faster than the peaks under artificial sprinkling condition. It was also observed that 85 Sr had two peaks in its concentration distribution curves. These phenomena are very important to safety assessment of radioactive waste disposal. (

关 键 词：核素迁移 放射性废物处置 安全评价 黄土包气带 

分 类 号：TL942[核科学技术—辐射防护及环境保护]