摘要
本文从物质的一维非稳态扩散规律出发，在常温、纯氮条件下，测定了２３９Ｐｕ、２４１Ａｍ、９９Ｔｃ和１３７Ｃｓ在作为高放废物深地质处置库缓冲材料的高压实钠质膨润土中的扩散系数。９０ｄ的实验测定结果表明：在膨润土的干密度为１．９ｇ／ｃｍ３时，２３９Ｐｕ、２４１Ａｍ扩散系数约为１０－１５ｍ２／ｓ，９９Ｔｃ约为１０－１３ｍ２／ｓ，而１３７Ｃｓ约为１０－１２ｍ２／ｓ，都随缓冲材料的干密度的增加而降低。经过对扩散系数、阻滞系数以及膨润土的干密度进行分析，认为Ａｍ、Ｐｕ主要以在固相中扩散为主，而Ｃｓ、Ｔｃ则偏向于在孔隙水中扩散。
Based on one dimension diffusion model,the diffusion coefficients of Pu、Am、Tc and Cs in highly compacted sodium bentonite generally used as buffer materials in geologic disposal system for high leavel radioactie waste have been determined at room temperature in the atmosphere of nitrogen.The results show that the diffusion coefficients of Am、Pu and Tc and about 10 -13 ～10 -15 m 2/s,and that of Cs about 10 -12 m 2/s.The diffusion coefficients of these elements decrease with the increasing of the dry density of buffer materials.From the relationship of diffusion coefficient,retardation coefficient and dry density of bentonite,it has been concluded that Am and Pu transfer predominately by diffusion in solid phase,hower,Cs and Tc by diffusion in pore water. (
出处
《辐射防护》
CAS
CSCD
北大核心
1998年第2期112-118,共7页
Radiation Protection
关键词
高放废物
深地质处置
缓冲材料
扩散系数
核素
Highly Level Waste,Geologic Disposal,Buffer Material,Sodium Bentonite,Diffusion Coefficient Nuclide)
