【摘要】 主要介绍在包气带黄土、含水层黄土和工程屏障材料(膨润土、水泥、变质水泥、砂浆粉)中,237Np2、38Pu2、41Am和90Sr迁移的野外试验、实验室模拟实验及工程屏障材料性能测定、黄土对核素吸附特性、化学形态等研究结果。在天然和喷淋两种条件下,237Np2、38Pu和241Am在包气带、含水层和工程屏障材料的野外试验中三年时间基本未移动。喷淋条件下,野外试验中90Sr通过石英砂示踪源层其质心位置1 079 d向下迁移2.7 cm,在示踪源层外6 cm处黄土中90Sr浓度峰在1 215 d向下迁移13 cm左右。在包气带模拟实验中,90Sr2、37Np2、38Pu和241Am在1号柱中经1 073 d分别向下迁移9.8 cm、3.25 cm、0.5 cm和0.25 cm。在含水层模拟实验中,经970.5 d,90Sr2、37Np2、38Pu和241Am分别迁移16 cm,4 cm、0.2 cm和0.2 cm。野外对比试验验证,在包气带中核素通过踪源层黄土载体向下迁移的距离是通过石英砂载体的3.6倍多。在完全相同条件下,Br迁移速度比3H略快。包气带石英砂示踪源层处,核素浓度分布出现低谷现象。CIRP试验场地下水中,237Np以离子态(V、V1价)存在为主,238Pu主要由以Ⅳ价离子态存在2。37Np不易形成真胶体。工程屏障材料、HA和FA的存在对核素化学形态有影响。更多还原

【Abstract】 This paper presents the research results on the field and laboratory tests of ²³⁷Np,²³⁸Pu,²⁴¹Am and ⁹⁰Sr migration,the determination of engineering barrier materials performance,and the nuclide-by-loess adsorption properties and their chemical speciation,which were conducted aerated zone loess and aquifer loess and engineering barrier materials made of bentonite,cement,degraded cement and mortar.Under both natural and sprinkling conditions,movement has hardly been found of ²³⁷Np,²³⁸Pu,and ²⁴¹Am in aerated zone,aquifer and engineering barrier materials in a three-year period.Under the sprinkling condition,a 2.7 cm downward movement of ⁹⁰Sr from the mass center of quartz sand trace layer was observed in the fieldwork in a（1 079） d period,with a about 13 cm downward movement of its concentration peak in the loess at a distance of about（6 cm） from the trace layer within the（1 215） d period.In the aerated zone test,⁹⁰Sr,²³⁷Np,²³⁸Pu,and ²⁴¹Am in Column 1,after（1 073） d,migrated downward 9.8 cm,（3.25 cm）,0.5 cm and 0.25 cm,respectively.In aquifer simulation test,they migrated downward,after 950.5 d,16 cm,（4 cm）,0.2 cm and 0.2 cm,respectively.The field contrast test performed within the aerated loess-zone demonstrates that nuclides move downward through the loess（of field） carrier of trace source layer at a faster rate than in the quartz sand carrier by a factor of about 3.6.Under the same condition,Br migrates somewhat faster than ³H.The phenomena of low valley were found in the nuclide concentration distribution over the quartz sand trace source layer.In the groundwater at CIRP Field Test Site,²³⁷Np with ion speciation and the valence of Ⅴ or Ⅵ dominate in their existence while ²³⁸Pu with ion speciation and the valence of Ⅳ is dominant.²³⁷Np is not apt to form collide.The existence of engineering barrier materials,humic acid（HA） and fumic acid（FA） has the influence upon chemical speciation of nuclides.更多还原