Tritium Separation from High Volume Dilute Aqueous Streams- Milestone Report for M3FT-15OR0302092

Bhave, Ramesh R.¹  Jubin, Robert Thomas¹  Spencer, Barry B.¹  Nair, S.² 

[1] Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States);Georgia Inst. of Technology, Atlanta, GA (United States)

关键词: tritium separation;    zeolite membrane;    pervaporation;   

DOI  :  10.2172/1254093
RP-ID  :  ORNL/TM--2016/99
PID  :  OSTI ID: 1254093
Others  :  Other: AF5805010
Others  :  NEAF327

学科分类：化学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

This report describes the synthesis and evaluation of molecular sieve zeolite membranes to separate and concentrate tritiated water (HTO) from dilute HTO-bearing aqueous streams. Several silico alumino phosphate (SAPO-34) molecular sieve zeolite membranes were synthesized and characterized with gas and vapor permeation measurements. The pervaporation process performance was evaluated for the separation and concentration of tritiated water. Experiments were performed over a range of tritiated water concentration covering the range of concentration anticipated in nuclear fuel processing where potentially both acid and water streams are recycled. The permeate was recovered under vacuum. The tritium concentration ranged from 0.5 to 1 mCi/mL which is about 0.1 mg/L or 0.1 ppm. The HTO concentration was three orders of magnitude lower than experiments performed with simulated feed containing HDO (>100 ppm) using deuterated water where high separation factors (>10) were obtained using SAPO membranes. Separation factor calculated from the measured tritium concentrations ranged from 0.83-0.98. Although the membrane performance characterization results were lower than expected, they can be explained on the basis of low feed volume and three orders of magnitude lower HTO concentration compared to HDO concentration in deuterated water. We have identified several new approaches, such as tuning the diffusion coefficient of HTO, that may help achieve preferential transport of tritium (HTO) resulting in a substantially more concentrated permeate.