权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Advanced study of tritium recovery from molten salt Flibe blanket in fusion reactor

聚变反应堆熔盐Flibe包层回收氚的最新研究

基本信息

批准号：
14380220
负责人：
FUKADA Satoshi
金额：
$ 4.8万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

Flibe (2LiF+BeF_2 mixed molten salt) is expected to be an advanced liquid blanket fluid for a helical-type DEMO fusion reactor called FFHR-2 because it has an ability of good thermal conductance and high tritium breeding ratio under high magnetic field and high-density neutron flux. However, it has disadvantages that it is difficult to handle tritium in the molten salt because of generation of tritium fluoride and the recovery and enclosure of tritium are difficult. Therefore, there was less application to conceptual design of fusion reactors and therefore less experimental studies on Flibe/tritium chemistry. In the present study, we investigated experimentally the permeability of hydrogen isotopes through Flibe and reduction-oxidation (redox) control by Be rods immersed in Flibe that will provide important data to design fusion reactors. The main purpose of the present study is to propose a new blanket circulation loop system composed of Flibe ducts, a tritium extraction system and a … More heat exchanger that can control to a rate lower than 10 Ci/day of acceptable tritium leak rate and a tritium concentration lower than 1 ppm of acceptable tritium inventory. The following findings were obtained from the experiment and analysis of the present study :1.We determined the permeability of deuterium through molten Flibe enclosed in a dual-tube Ni permeation vessel. Judging from the permeability, diffusivity and solubility of deuterium in Flibe, hydrogen isotopes are resent as a H^+ ion in Flibe. Therefore strong interaction between H^+ and F^- ions was observed, and HF (DF or TF) is a main species diffusing in non-redox controlled Flibe.2.We determined hydrogen H_2 through Flinak (a LiF+NaF+KF mixed molten salt), and hydrogen was present as a molecular form in it. This is because there is no tetragonal network of BeF_4^<2-> different from the Flibe case. F^- ions in Flinak were localized in the vicinity of Li^+, K^+ and Na^+ ions. In other words, there are much less free F^- ions in Flinak, and therefore Flinak corresponds to the well redox-controlled Flibe.3.Flibe was successfully redox-controlled by Be immersed in it. This is because free F- ions that were present in non-controlled Flibe were changed to BeF_2 by the reaction with Be dissolved in Flibe physically. The free F^- ions were consumed by the redox reaction and hydrogen in Flibe was present in a molecular form. Consequently, tritium will be present in a molecular form in well redox-controlled fusion reactor blankets when Be is used as a neutron multiplier.4.In order to maintain the tritium leak rate in a 1GW fusion reactor lower than the acceptable level (10 Ci/day), we need a sophisticated tritium recovery system made of low permeable materials. We provided design equations for tritium permeable window, bubbling tower and spray tower for high tritium recovery, and each apparatus was designed using the equations. Less

Flibe（2LiF+BeF_2混合熔盐）具有良好的导热性能，在强磁场和高密度中子注量下具有较高的氚增殖率，有望成为螺旋型DEMO聚变堆FFHR-2的先进液态包层流体。但其缺点是，由于氟化氚的生成，熔融盐中的氚难以处理，并且氚的回收和封闭困难。因此，很少应用于聚变反应堆的概念设计，因此很少进行Flibe/氚化学的实验研究。在本研究中，我们实验研究了氢同位素通过Flibe的渗透性和还原-氧化（氧化还原）的控制，浸没在Flibe的Be棒，将提供重要的数据，设计聚变反应堆。本研究的主要目的是提出一种新的包层循环回路系统，该系统由Flibe管道、氚提取系统和 ...更多信息热交换器，其可以控制到低于10 Ci/天的可接受的氚泄漏速率和低于1 ppm的可接受的氚存量的氚浓度。通过实验和分析，获得了以下主要结果：1.测定了氘在双管镍渗透器中的Flibe熔体中的渗透率。从氘在Flibe中的渗透性、扩散性和溶解度来看，氢同位素在Flibe中以H^+离子的形式存在。2.通过Flinak（LiF+NaF+KF的混合熔盐）测定了H_2的存在，发现H_2是以分子形式存在的，这是因为Flinak中没有BeF_4 ~* 的四面体网络结构<2->。Flinak中的F^-离子位于Li^+、K^+和Na^+离子附近。Flinak中的游离F ~-离子少得多，因此Flinak对应于氧化还原控制良好的Flibe。3. Flibe被浸没在其中的Be成功地氧化还原控制，这是因为存在于未被控制的Flibe中的游离F ~-离子通过与溶解在Flibe中的Be的物理反应而转化为BeF_2。游离的F^-离子被氧化还原反应消耗，Flibe中的氢以分子形式存在。因此，当铍用作中子倍增剂时，氚将以分子形式存在于良好的氧化还原控制的聚变堆包层中。4.为了使1GW聚变堆的氚泄漏率低于可接受的水平（10 Ci/d），我们需要一个由低渗透材料制成的复杂的氚回收系统。给出了高氚回收率的透氚窗、鼓泡塔和喷淋塔的设计公式，并利用这些公式对各装置进行了设计。少