Diffusion characteristics of HTO and 99TcO_4^- in compacted Gaomiaozi(GMZ) bentonite

作     者：Tsuey-Lin Tsai Shih-Chin Tsai Yu-Hung Shih Liang-Cheng Chen Chuan-Pin Lee Te-Yen Su 

作者机构：Chemistry Division Institute of Nuclear Energy ResearchNo. 1000 Wenhua Rd. Jiaan Village Longtan DistrictTaoyuan China Nuclear Science and Technology Development CenterNational Tsing Hua University Hsinchu China Department of Earth Sciences National Cheng Kung University No. 1 University Road Tainan China 

出 版 物：《Nuclear Science and Techniques》 (核技术（英文）)

年 卷 期：2017年第28卷第5期

页      面：60-67页

核心收录：

学科分类：082704[工学-辐射防护及环境保护] 08[工学] 0807[工学-动力工程及工程热物理] 0827[工学-核科学与技术] 0703[理学-化学] 0702[理学-物理学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：the Nuclear Backend Management Department at Taiwan Power Company for financially supporting this research 

主　　题：Distribution coefficient Apparent diffusion coefficient Effective diffusion coefficient Compacted bentonite Through-diffusion 

摘      要：The characteristics of diffusion are essential to the transport of radionuclides through buffer/backfill materials, such as bentonite, which are commonly found in waste repositories. This study used through-diffusion techniques to investigate the diffusion behavior of HTO and ^(99)TcO_4^- on GMZ bentonite of various densities. Diffusion rates were calculated by measuring the diffusion coefficients(De, Da), plotting breakthrough curves and interpreting experiment data. The apparent and effective diffusion coefficients of HTO ranged from(1.68 ± 0.40) 9 × 10^(-11) to(2.80 ± 0.62) 9 × 10^(-11) m^2/s and from(4.61 ±1.28) 9 × 10^(-12) to (16.2 ± 2.50) 9 × 10^(-12) m^2/s, *** apparent and effective diffusion coefficients of^(99)TcO_4^-ranged from(5.26 ± 0.16) 9 × 10^-12to(7.78 ± 0.43) 9× 10^-12m^2/s and from(1.49 ± 0.002) 9 × 10^(-12) to(4.16 ±0.07) 9 × 10^(-12) m^2/s, respectively. The distribution coefficients of HTO and^(99)TcO_4^-ranged from(0.70 ± 0.12) 9× 10^(-2) to(1.36 ± 0.53) 9 × 10^(-2) mL/g and from(1.12 ±0.06) 9 × 10^(-2) to(5.79 ± 2.22) 9 × 10^(-2) mL/g, *** Deand Kdvalues were shown to decrease with an increase in the bulk dry density of compacted bentonite. Our results show that HTO and ^(99)Tc could be considered nonsorbent radionuclides. The data obtained in this studyprovide a valuable reference for the safety assessment of waste repositories.