聚变驱动次临界堆双冷嬗变包层热工水力学参数设计与分析

聚变驱动次临界堆双冷嬗变包层是一个以氦气和液态金属LiPb为冷却剂,以嬗变核废料为主要目的的多功能包层。依据功率平衡模型对不同工况优化的基础上,对该包层热工系统参数进行了设计分析。采用三维商用计算流体力学程序对第一壁和高功率密度区中液态LiPb的流场进行数值模拟计算,给出了优化的典型热工水力参数。     

聚变驱动次临界堆嬗变包层双流场三维数值模拟与分析

采用流体动力学数值模拟软件对聚变次临界堆双冷嬗变包层高功率密度区 (FW、HM1 )液态金属LiPb和氦气流场进行三维数值模拟 ,考察双流场温度分布、LiPb向氦气传热热流密度场等 ,为聚变次临界堆热工水力学设计提供决策依据     

聚变发电反应堆双冷液态锂铅包层模块结构设计与分析

给出聚变发电反应堆FDS Ⅱ模块式液态锂铅包层(DLL)结构方案,以低活化马氏体(RAFM)钢为结构材料,采用液态金属LiPb作为增殖材料和冷却剂,使用碳化硅流道插件作为电绝缘和热绝缘。包层的设计特点体现在:从增殖区、冷却剂流道、屏蔽包层、母管、机械连接、维修装配等几个方面全局考虑包层设计,结构布置完整;独有的“”形隔板设计使氦气冷却回路容易实现,增殖流道简单,可简化制造工艺,提高可靠性。同其他液态锂铅包层相比,DLL包层在冷却剂系统、制造、装配上可成就较高的可行性。     

聚变驱动次临界堆概念设计研究

在深入分析相关领域研究发展状况的基础上,提出一个可实现核废料嬗变、可裂变重金属核燃料和氚核燃料增殖、产能等多种功能的次临界反应堆概念。概念有托卡马克实验装置参数适量外推的等离子体物理和技术水平的聚变堆芯、高压He气/液态LiPb双冷却系统嬗变包层。介绍了系统基本概况和参考结构形式,阐述了系统聚变等离子体物理学、包层中子物理学和包层热工水力学设计的基本原则和主要工程约束限制条件,指出系统相关的安全和潜在环境影响问题,给出典型的参考设计参数。     

高温包层内多层插件流道内液态铅锂MHD流动数值分析

包层是聚变反应堆能量转换和提取的关键部件,聚变高温制氢堆(FDS-Ⅲ)高温液态铅锂包层(HTL)中采用创新型多层插件(MFCI)技术,由SiC_f/SiC组成的流道插件使液态铅锂实现了1 000℃左右出口温度,从而达到更高的热电转换效率和制氢能力。液态金属磁流体动力学效应MHD效应是HTL包层的重点问题之一。本文以高温包层结构为参考,采用FDS团队自主开发的磁流体动力学与热工水力学耦合模拟软件MTC,对高哈特曼数下典型多层插件流道内的液态铅锂MHD流动特性进行了数值模拟,分析了不同插件电导率对流道之间电磁耦合现象的影响。     

聚变发电反应堆双冷锂铅包层热工水力学设计与分析

依据结构设计和中子学计算结果给出了聚变发电反应堆FDS-Ⅱ双冷锂铅(DLL)包层热工水力学设计方案。采用数值计算软件对液态金属增殖区LiPb流场和第一壁热-结构等进行了模拟,并对功率转换系统的热效率进行了计算。通过分析评估,证实该包层热工水力学方案能较好地实现FDS-Ⅱ聚变发电反应堆预期目标。     

中国液态锂铅包层材料研究进展

液态锂铅包层是国际上普遍关注和最有发展潜力的聚变堆包层概念设计之一,而包层材料是液态锂铅包层的核心问题之一.目前,液态锂铅包层普遍选用低活化铁素体/马氏体钢(RAFM钢)作为结构材料,液态锂铅作为中子倍增剂及氚增殖剂.另外,部分设计采用了耐高温、电绝缘流道插件作为功能材料,以降低磁流体动力学效应及提高冷却剂出口温度(高于700℃).为适应液态包层的发展需求,中国科学院等离子体物理研究所FDS团队联合国内外相关研究单位,进行了具有中国自主知识产权的中国低活化马氏体钢(CLAM钢)及液态锂铅包层功能材料研发,并开展了锂铅热对流及强迫对流回路的设计、研制及腐蚀实验研究,以研究液态金属锂铅的流动特性及其与结构和功能材料的相容性.同时建立了聚变堆材料数据库平台,为促进中国聚变堆液态包层及材料技术的研究和发展提供数据支持.     

托卡马克工程试验增殖堆Li冷包层的磁流体动力学压降分析

本文对液态金属 Li 流过托卡马克工程试验增殖堆自冷包层的磁流体动力学(MHD)压降进行了分析,讨论了内侧包层有无裂变、燃料元件的形式、包层能量倍增因子 M 及第一壁冷却孔道宽度对包层总压降的影响,从 MHD 流动分析的观点,为中子学、结构和热工水力设计提出了设计要求。     

聚变发电反应堆双冷锂铅包层结构温度和应力计算分析

使用有限元程序对聚变发电反应堆FDS-Ⅱ双冷锂铅包层结构进行数值模拟,依据结构设计、热工水力学参数和中子学计算参数,给出对应包层结构温度场和应力场分布,同时分析了液态金属LiPb碳化硅流道插件的温度、应力及变形。依据温度场和应力场模拟结果,对FDS-Ⅱ双冷锂铅包层设计方案在等离子体稳态运行条件下进行可行性分析。     

聚变堆液态金属锂铅包层多功能涂层研发

液态金属锂铅包层是目前国际上聚变堆包层设计研究的主要方案之一,结构材料表面制备涂层是降低锂铅包层中的氚渗透率、液态锂铅腐蚀及磁流体动力学(MHD)效应的重要技术之一.本文主要从涂层材料及其制备工艺两个方面重点介绍了国内外在液态锂铅包层涂层材料研发方面的进展概况,并对涂层技术发展进行了展望,最后提出了中国发展液态锂铅包层涂层的规划建议.     

低环径比聚变托卡马克液态金属包铜中心导体柱

低环径比(LAR)聚变托卡马克可作为一种紧凑中子源,为聚变早期利用提供了有效途径。本文针对其关键部件中心导体提出新颖液态金属(LM)包钢中心导体往设计结构,其结构由既可增殖氚又可降低导体辐照损伤的防护层和负载巨大电流(>10MA)的中心导体区组成。与常规中心导体柱(CCP)相比,其优势在于:防护区减小了铜导体的辐照损伤;提高了中子利用率及氚增殖率;优化结构的铜导体,保证了较低的欧姆损耗。     

氧势对快堆不锈钢包壳管腐蚀行为的影响

通过堆外模拟试验，研究了国产３１６－Ｔｉ不锈钢包壳管在４种氧势下对ＦＣＣＩ（燃料包壳化学相互作用）和ＦＰＬＭＥ（裂变产物液态金属脆化效应）的敏感性。结果表明包壳管腐蚀特征与氧势密切相关。当氧势低于Ｃｒ在不锈钢中的氧化阈值，包壳管内壁无明显侵蚀；当氧势超过Ｃｒ在不锈钢中的氧化阈值很多时，包壳管微观侵蚀形貌是基体氧化侵蚀与晶间侵蚀（ＩＧＡ）的混和。随氧势增加，晶间侵蚀深度减小，氧化侵蚀变严重。在与超化学计量混合氧化物燃料对应的高氧势下，同时发生基体氧化侵蚀，晶间侵蚀和剥离性侵蚀，侵蚀区呈“溃疡状”，由富Ｃｒ／贫Ｎｉ和富Ｎｉ／贫Ｃｒ层交替组成。     

基于弥散燃料颗粒开裂的金属基体裂纹特征模型

金属基弥散燃料元件在特殊工况下会发生表面起泡失效。燃料颗粒开裂是金属基体开裂的前提条件,只有当金属基体开裂后元件才会发生表面起泡。燃料颗粒开裂后,裂纹宽度和塑性区长度等裂纹特征决定了金属基体开裂行为。基于弹塑性断裂力学和应力平衡条件,建立了基于弥散燃料颗粒开裂的金属基体裂纹特征模型。计算结果表明：裂纹张开位移随退火温度和燃耗深度的升高而增加;裂纹尖端塑性区长度主要与退火温度相关。裂纹张开位移和塑性区长度的计算结果与实验数据均符合较好,验证了金属基体裂纹特征模型的有效性。     

Influence of liquid lead and lead-bismuth eutectic on tensile, fatigue and creep properties of ferritic/martensitic and austenitic steels for transmutation systems

In this paper, the tensile, fatigue and creep properties of the Ferritic/Martensitic (F/M) steel T91 and of the Austenitic Stainless (AS) Steel 316L in lead-bismuth eutectic (LBE) or lead, obtained in the different organizations participating to the EUROTRANS-DEMETRA project are reviewed. The results show a remarkable consistency, referring to the variety of metallurgical and surface state conditions studied. Liquid Metal Embrittlement (LME) effects are shown, remarkable on heat-treated hardened T91 and also on corroded T91 after long-term exposure to low oxygen containing Liquid Metal (LM), but hardly visible on passive or oxidized smooth T91 specimens. For T91, the ductility trough was estimated, starting just above the melting point of the embrittler (T_M,E = 123.5 °C for LBE, 327 °C for lead) with the ductility recovery found at 425 °C. LME effects are weaker on 316L AS steel. Liquid Metal Assisted Creep (LMAC) effects are reported for the T91/LBE system at 550 °C, and for the T91/lead system at 525 °C. Today, if the study of the LME effects on T91 and 316L in LBE or lead can be considered well documented, in contrast, complementary investigations are necessary in order to quantify the LMAC effects in these systems, and determine rigorously the threshold creep conditions.     

启明星1#实验装置ks、keff和φ*的模拟计算

用MCNP程序对启明星1#实验装置（Venus1#）的k_s、k_eff和φ^*进行模拟计算。在装置的源区、快区、反射层、屏蔽层已定条件下,逐层增加热区燃料元件,每增加1层,对k_s、k_eff和φ^*进行1次计算,共增加了13层,最终得到k_eff为0.96246,满足了Venus1#的设计要求。元件层数增加,φ^*先增后降,当增至12层时,φ^*又明显增大。外源位置和能量对φ^*有影响,外源在轴向离中心越近、能量越高,φ^*越大。     

Analysis of titanium coatings deposited and exposed in macrotor and microtor

Metal coatings of Ti are vapor-deposited (200 A/day) in MACROTOR and MICROTOR during low temperature H₂-discharge cleaning and operated far away from the gettering threshold for plasma impurity control. Several methods of analysis (X-ray diffraction, ESCA, AES, SEM) show that after several months of deposition two major effects have an impact on the coating: (a) formation of a porous microstructure which enhances H₂,-gas trapping: (b) formation of Ti-hydride of a 100 Å crystallite size and with large microstrain present. Both effects are responsible for a mechanically and chemically unstable first wall. H/D-exchange and H-retention are affected most by the existing wall condition. These difficulties may be avoided by using a hot (≈400°C) liner.     

Mechanical properties and microstructural investigations of TIG welded 40 mm and 60 mm thick SS 316L samples for fusion reactor vacuum vessel applications

The development of advanced fusion reactors like DEMO will have various challenges in materials and fabrication. The vacuum vessel is important part of the fusion reactor. The double walled design for vacuum vessel with thicker stainless steel material (40–60 mm) has been proposed in the advanced fusion reactors like ITER. Different welding techniques will have to be used for such vacuum vessel development. The required mechanical, structural and other properties of stainless steels have to be maintained in these joining processes of components of various shapes and sizes in the form of plates, ribs, shells, etc. The present paper reports characterization of welding joints of SS316L plates with higher thicknesses like 40 mm and 60 mm, prepared using multi-pass Tungsten Inert Gas (TIG) welding process. The weld quality has been evaluated with non-destructive tests by X-ray radiography and ultrasonic methods. The mechanical properties like tensile, bend tests, Vickers hardness and impact fracture tests have been carried out for the weld samples. Tensile property test results indicate sound weld joints with efficiencies over 100%. Hardening was observed in the weld zone in non-uniform manner. Macro and microstructure studies have been carried out for Base Metal (BM), Heat Affected Zone (HAZ) and Weld Zone (WZ). Scanning Electron Microscopy (SEM) analysis carried out for the impact fractured specimens show ductile fracture. The microstructural study and ferrite number data indicate the presence of high content of delta ferrite in the weld zone as compared to the delta ferrite in base metal.     

东昆仑隆升作用的裂变径迹研究

对东昆仑山东段都兰-布青山近南北向剖面采集样品进行了磷灰石裂变径迹分析。所获得的41件磷灰石裂变径迹年龄变化介于25～130Ma之间，均低于其岩石形成年龄。昆北区和昆中区有着类似的演化趋势，即裂变径迹年龄随高程的增加而缓慢减小，平均隆升速率仅为2．22m／Ma。与之不同，昆南区裂变径迹年龄与高程呈正比，变化率为11m／Ma。昆南断裂带两侧地区截然相反的演化关系表明，昆南断裂带在进入陆内演化后所起的作用比昆中断裂带更为重要。     

Microanalysis of a submicron patterned WSix structure using a nuclear microprobe

A metal-silicide wiring structure with submicron lateral feature size was analyzed successfully by a nuclear microprobe with a Liquid Metal Ion Source (LMIS). A minimum beam spot size of less than 80 nm at a current of 30 pA with a 300 keV Be²⁺ beam was used. The lateral distribution of WSi_x at submicron level was resolved using RBS mapping and tomographic imaging. The localized silicidation behavior between WSi_x on Si and on SiO₂ was compared by microbeam RBS measurement.     

Effects of Ag and Au ion implantation of lithium niobate

The optical effects of implantation of lithium niobate crystals with 100 keV Ag⁺ and 8 MeV Au³⁺ ions with fluences of 1 × 10¹⁷ ions/cm² have been investigated. Metal nanoparticle formation has been studied as a function of annealing temperature, and the resulting optical extinction curves have been simulated by the Mie theory in the small particle limit. Transmission electron microscopy (TEM) has provided direct evidence for the MNP sizes allowing comparison with the calculated results. A TEM study of an X-cut sample implanted with Ag⁺ ions show that the implanted region is partially amorphised. The differences in the temperature of Au colloid development in X- and Y-cut faces of the lithium niobate crystal are attributed to restoration of crystallinity as a result of annealing.