联合电解催化交换系统的动态模型及理论计算

为探求联合电解催化交换系统各单元中氚浓度空间分布和动态变化的内在规律，建立了D／T体系的气-液两元模型。根据不同的催化剂传质性能，计算了为达到特定脱氚率和电解池浓缩倍数所要求的交换床总高度和进液位置。理论计算得到的氚在交换床上的空间分布趋势与文献报道的中试结果一致，电解池中的氚浓度随时间呈线性增长。     

整体式除氚催化剂的制备及催化氧化性能

针对大型核设施产生的大流量废气的处理,发展低气阻的整体式催化剂尤为必要.本工作在整体式堇青石载体上生长分子筛涂层,以离子交换法负载活性组分Pt,获得的整体式催化剂具有高的金属分散度,达到了60％.使用该催化剂,在15℃、体积空速为10000～40000 h-1、1.0％(体积分数)H2的条件下实现大于99.9％ 的H2...     

空气除氚系统中氚氧化催化剂的研究进展

在大型氚设施中空气除氚系统必不可少,通过气-水转换除去气态氚是目前应用最广泛也是最有效的工艺,过程中氧化催化剂至关重要。总结了气态氚的催化氧化研究进展、催化剂的催化性能及影响催化性能的主要因素。贵金属Pt和Pd在室温下对氚的转化效率接近100%,因而被广泛用于氚的催化氧化。通过负载分散载体、添加催化助剂、使用规整结构催化剂、设计新型的催化反应器能够进一步提高催化剂性能。以蜂窝状催化剂为研究热点的规整结构催化剂以其高比表面积和低压力降而显示出良好的催化性能,将它用于氚的催化氧化,是该领域的一个研究方向。氢、氘、氚在氧化过程中的同位素效应会影响除氚效率,需进行深入研究。     

氢-水同位素交换及其应用研究进展

简要介绍了氢气与水之间的氢同位素交换(氢—水同位素交换)的原理和相关理论研究,重点阐述了几种主要氢—水同位素交换工艺的研究和应用进展,并对氢—水同位素交换工艺在氢同位素分离中的应用前景进行了评述。     

Design Study of Feasible Water Detritiation Systems for Fusion Reactor of ITER Scale

Two types of water detritiation systems have been designed for fusion reactors of ITER scale. One of the systems is a combination of WD (Water Distillation) and VPCE(vapor phase catalytic exchange) columns. The other is a combination of a WD column and a CECE(combined electrolysis catalytic exchange) column. Three water distillation columns are needed for the former system. The total height of the three columns is 106 m. The height of the water distillation and CECE columns for the latter system are 20 and 24m, respectively. These large water distillation columns result in the larger tritium inventory of the former system than for the latter system. However, there have been the results for the operation of the actual scale of the water distillation and VPCE columns. No demonstration test has been carried out for the CECE column. From these reasons, the WD+VPCE system should be the first candidate for the fusion reactor. The WD+CECE system is superior to the WD+VPCE system for the flexibility in design as well as the tritium inventory. It is desired to demonstrate the CECE column to develop the water detritiation system best suited to the fusion reactors.     

重水蒸汽回收系统失效干燥剂减量化处理初探

从放射性废物减量化管理原则出发,探讨了重水蒸汽回收系统干燥剂分类进行除氚处理和水泥固化的技术路线,对干燥剂进行除氚处理使其满足清洁解控标准,对无法满足解控标准的干燥剂与含硼浓缩液进行混合固化处理。初步试验结果表明,利用高温加热和微波处理可实现干燥剂的除氚处理;干燥剂与含硼浓缩液混合固化是可行的。     

Effect of hydrocarbons on the efficiency of catalytic reactor of detritiation system in an event of fire

Detritiation system of a nuclear fusion plant is mandatory to be designed and qualified taking carefully into consideration all the possible extraordinary situations in addition to that in a normal condition. We focused on the change in the efficiency of tritium oxidation of a catalytic reactor in an event of fire where the air accompanied with hydrocarbons, water vapor, and tritium is fed into a catalytic reactor at the same time. Our test results on the effect of these gases on the efficiency of tritium oxidation of the catalytic reactor indicated; (1) tritiated hydrocarbon produces significantly by reaction between tritium and hydrocarbons in a catalytic reactor; (2) there is little possibility of degradation in the detritiation performance because the tritiated hydrocarbons produced in the catalyst reactor are combusted; (3) there is no possibility of uncontrollable rise in the temperature of the catalytic reactor by heat of reactions; and (4) saturated water vapor could temporarily poison the catalyst and degrades the detritiation performance. Our investigation indicated a saturated water vapor condition without hydrocarbons would be the dominant scenario to determine the amount of catalyst for the design of catalytic reactor of the detritiation system.     

Separation process study of liquid phase catalytic exchange reaction based on the Pt/C/PTFE catalysts

The liquid phase catalytic exchange(LPCE) reaction is an effective process for heavy water detritiation and production of deuterium-depleted potable water. In the current study, hydrophobic carbon-supported platinum catalysts(Pt/C/PTFE) with high efficiency as reported previously for LPCE were prepared and comprehensive performance evaluation method is applied to evaluate the separation behaviors of LPCE systematically. Experimental results indicate that the optimum reaction temperature of 60–80 °C and the molar feed ratio G/L of 1.5–2.5 would lead to higher separation efficiencies. As to the packing method, a random packing mode with a packing ratio of hydrophobic catalysts 0.25 is recommended. In addition, thermodynamic analysis corresponds well with experimental results under lower temperature and G/L, while the suppression of kinetic factors should not be neglected when T 80 °C and G/L 1.5.     

Influence on moisture and hydrocarbons on conversion rate of tritium in catalytic reactors of fusion-DEMO detritiation system

Thoughtful consideration of abnormal events such as fire is required to design and qualify a detritiation system (DS) of a nuclear fusion facility. Since conversion of tritium to tritiated vapor over catalyst is the key process of the DS, it is indispensable to evaluate the effect of excess moisture and hydrocarbons produced by combustion of cables on tritium conversion rate considering fire events. We conducted demonstration tests on tritium conversion under the following representative conditions: (I) leakage of tritium, (II) leakage of tritium plus moisture, and (III) leakage of tritium plus hydrocarbons. Detritiation behavior in the simulated room was assessed, and the amount of catalyst to fulfill the requirement on tritium conversion rate was evaluated. The dominant parameters for detritiation are the concentration of hydrogen in air and catalyst temperature. The tritium in the simulated room was decreased for condition (I) following ventilation theory. An initial reduction in conversion rate was measured for condition (II). To recover the reduction smoothly, it is suggested to optimize the power of preheater. An increase in catalyst temperature by heat of reaction of hydrocarbon combustion was evaluated for condition (III). The heat balance of catalytic reactor is a point to be carefully investigated to avoid runaway of catalyst temperature.     

Residual tritium effects during spill clean-up

The specific activity of the moisture in the exhaust gas from a dryer was measured at various conditions. It approximately equalled that of the residual moisture left on the adsorbent during the previous regeneration. Modeling was used to demonstrate that this residual tritium can affect emissions and occupational dose during chronic or acute detritiation, and should be accounted for during ADS design and analysis.