Study on Isotope Enrichment of Nitrogen-15 with Cascading Assembly of Thermal Diffusion Columns

已经开发了一个数字模拟系统，以分析氮同位素分离中的热扩散柱的同位素分离性能。热扩散柱中的氢动力学流动已经进行了数值模拟和质量数的硝基分子部分， 28、29和30被计算为垂直和激进位置的功能，通过卷积扩散equation解决。热扩散因子，在分析中，它是最重要的价值，在实际的形式中被表达出来，仍然与通用的Stefan-Maxwell等式保持一致的关系，适用于硝基同位素的多成分混合。在我们的研究中，氮分子的非弹性聚集的影响被认为对热扩散因子的影响。The effect of Cold wall temperature on separation perature for y D114-D1 N-D115--D1 N和D114--D1 N--D22--D2 separation被评估为数值模拟系统，并与实验结果相比较，与一个有效高度的热扩散列，在950 mm的一根热线，在半径为0.15mm的一根冷墙和在半径为5.0mm的一根冷墙。该解决方案的数值分析对切割和冷壁温度的分离因素的依赖性进行了良好的复制，并研究了一个设计示例，作为一个由10米的有效高度的热扩散柱组成的级联。需要一个系列的热扩散柱的阶段有5个，因此以达到D115 D1 N的最后填充量的99.9%。热扩散柱的总数估计为89，600在一个工厂生产的D115 D1 N将满足联合国燃料一年内一个快速呼吸反应堆的电力1千兆瓦的发电量的需求。

A numerical simulation system was developed to analyze isotope separation performance in the thermal diffusion column for nitrogen isotope separation. Hydrodynamic flow in the thermal diffusion column was numerically simulated and mole fractions of nitrogen molecules of mass numbers, 28, 29 and 30 were computed as function of vertical and radical positions by solving a convective diffusion equation. The thermal diffusion factor, which is most important value in the analysis, was expressed in a practical form, still keeping consistent relationship with generalized Stefan-Maxwell equation, applicable to multi-component mixture of nitrogen isotopes. In our study, the effect of inelastic collision of nitrogen molecules was considered to the thermal diffusion factor. The effect of cold wall temperature on separation performance for ィイD114ィエD1N-ィイD115ィエD1N and ィイD114ィエD1NィイD22ィエD2 separation was evaluated with the numerical simulation system and compared with experimental results with the thermal diffusion column of an effective height of 950mm, a hot wire of 0.15mm in radius and a cold wall of 5.0mm in radius. The solutions numerical analyses gave good reproduction of dependence of separation factors on cut and cold wall temperature.Studied as a design example was cascade composed with an assembly of thermal diffusion columns of an effective height of 10m. The number required for a series of stages of the thermal diffusion column was 5 so as to achieve the final enrichment of 99.9% of ィイD115ィエD1N. The total number of the thermal diffusion columns was evaluated 89,600 in a plant which produces ィイD115ィエD1N to meet the demand for UN fuel of one fast breeder reactor of 1 GW electric power in a year.