次临界系统处理钚及高放锕系元素的概念研究

对加速器驱动的次临界反应堆处理反应堆级钚和高放锕系废物进行了概念性设计的研究 .建立了以液态铋系合金金属为载热剂的次临界堆芯模型 ,利用 ADVBISON程序对该问题进行了数值计算 ,得到了满意的中子学、燃耗和放射性衰变等结果.Disposition of the reactor plutonium and high level actinides by using accelerator driven subcritical reactor was studied theoretically and the corresponding core model using liquid Bi alloy as the reactor coolant was proposed. The satisfied numerical results of neutronics, burn up and radioactivity were obtained by the ADVBISON code.     

时空中子倍增公式解法研究

通过将空间概念引入中子倍增公式, 建立了时空中子倍增公式, 针对时空中子倍增公式计算时间效率过低的缺点, 对时空倍增公式的计算方法进行了研究, 新解法在保证精确性的基础上, 又提高了计算效率。新的计算方法可以应用于研究反应堆反应性发生动态变化的情况, 例如反应堆启堆或停堆以及变功率运行的过程, 对具有很强机动性要求的小型反应堆的安全分析有一定的理论意义和实用价值。 The space time neutron multiplication formula was established by introducing the concept of space time to the neutron multiplication formula. Because of the rather long computing time by using the formula, the solution of space time neutron multiplication formula is optimized which is efficient and accurate. The new method can be used to study the reactor with dynamic change in reactivity. It can be also used for studying the process of startup, outage and power drawn operation, which is of great importance to the safety analysis of the mini nuclear reactor.     

考虑热传递时有温度反馈的缓发超临界过程分析

对输入小阶跃反应性（ρ0〈β）、有热传递和温度反馈时反应堆缓发超临界过程进行了研究。提出了一个新的物理模型,由数值计算求出任意初始功率条件下反应堆反应性、功率随时间的变化规律,并进行分析讨论,给出了一些有益的新结果。The delayed supercritical process of nuclear reactor with temperature feedback and heat transfer while inserting small step reactivity（ρ0〈β）is analyzed. A new model is proposed. For an initial power, the variations of output power and reactivity with time are obtained by numerical method. The results are analyzed and discussed. Some useful new conclusions are drawn.     

利用高能离子模拟研究反应堆结构材料中的辐照效应

简要介绍了载能粒子辐射损伤对反应堆结构材料性能的影响,阐述了载能粒子束特别是高能离子束开展模拟研究的优势,并举例说明了国内利用高能重离子模拟研究反应堆结构材料辐射效应取得的进展。实验结果和理论分析表明,载能离子特别是高能离子辐照非常适合用于模拟研究反应堆结构材料中由粒子辐射引起的材料微观结构和宏观性能变化,是模拟研究反应堆结构材料辐射效应的非常有效的手段。 Radiation damage in structural materials of fission/fusion reactors is mainly attributed to the evolution of intensive atom displacement damage induced by energetic particles （ n, α and/or fission fragments） and highrate helium doping by direct α particle bombardments and/or （n, α） reactions. It can cause severe degradation of reactor structural materials such as surface blistering, bulk void swelling, deformation, fatigue, embrittlement, stress erosion corrosion and so on that will significantly affect the operation safety of reactors. However, up to now, behavior of structural materials at the end of their service can hardly be fully tested in a real reactor. In the present paper, damage process in reactor structural materials is briefly introduced, then the advantages of energetic ion implantation/irradiation especially high-energy heavy ion irradiation are discussed, and several typical examples on simulation of radiation effects in reactor candidate structural materials using high-energy heavy ion irradiations are introduced. Experimental results and theoretical analysis suggested that irradiation with energetic particles especially high-energy heavy ions is a very useful technique for simulating the evolution of microstructures and macro-properties of reactor structural materials.     

Effect of Reactor Pressure on Qualities of GaN Layers Grown by Hydride Vapour Phase Epitaxy

The influence of reactor pressure on GaN layers grown by hydride vapour phase epitaxy （HVPE） is investigated. By decreasing the reactor pressure from0. 7 to 0.5 mm, the GaN layer growth mode changes from the island-like one to the step flow. The improvements in structural and optical properties and surface morphology of GaN layers are observed in the step flow growth mode. The results clearly indicate that the reactor pressure, similarly to the growth temperature, is One of the important parameters to influence the qualities of GaN epilayers grown by HVPE, due to the change of growth mode.     

用离子辐照模拟研究反应堆结构材料中金属/金属界面原子扩散行为

介绍了利用载能离子辐照模拟研究反应堆结构材料中金属／金属界面原子扩散行为的实验进展,特别是辐照参数（如辐照剂量、辐照温度、核能损、电子能损以及膜结构等）对界面原子扩散行为的影响,并对可能的机理进行了简要的评述。 Atom diffusion at metal/metal interfaces is very important for property of reactor structural materials, which can be simulated by using energetic ion irradiations. The present situation of experimental studies on atom diffusion at metal/metal interfaces induced by energetic ion irradiations is reviewed. The influence of experimental parameters such as the irradiation dose, irradiation temperature, electronic energy loss, nuclear energy loss and the interface structure on the intermixing is emphatically introduced. In addition, the possible mechanisms of metal/ metal intermixing are also briefly described.     

300＃反应堆及其在核技术中的应用

３００~＃反应堆是一座池式研究用反应堆．本文介绍该堆的基本特性、堆上的一些实验装置及其性能;综述了在该堆上所做的中子物理、核物理、核化学和材料科学等方面的工作,以及某些中子辐照产品及其应用的概况． reactor is a pool type of research reactor. In this paper the basic featureof the reactor, and several experimental devices and their properties are introduced. It wassummarized that the experiment and study work is developed on the reactor, such as neutronand nuclear physics, nuclear chemistry, material science, and a few irradiated products byneutron and their applications and so on.     

Research and Development of SWITRIM Code and Its Applications

The ftrst numerical simulation code package WITRIM has been developed to calculate the tritium inventory distribution and time-evolution in all sub-systems of FEB fusion reactor. The applications during recent six years indicate that it is reasonable and fully admitted by colleagues abroad. Some creative papers with new concept are published. For instance, we first time pointed out a new phenomenon of ＂tritium well depth and tritium well time＂ during the fusion reactor start-up phase. This is somewhat similar to, but quite different from the ＂iodine well depth and iodine well time＂ poisoning problem during restart-up process of a fission reactor. The authors not only proposed but also numerically solved this new phenomenon. The combination of the SWITRIM code package, user＇s guide, and application example are briefly introduced in this article.     

The progress of nuclear pumped laser in CFBR-II reactor

Development of nuclear pumped lasers (NPL) in the CFBR-Ⅱ reactor is briefly reviewed. The results of the two NPL experiments in CFBR-Ⅱ reactor are described. The first one focused on the principle of nuclear pumped laser, and 4-mW laser output power achieved. The second NPL experiment focused on the small signal gain and the efficiency of the nuclear pumped He-Ar-Xe gas mixture at 1.73 μm. The maximum laser power measured to be 45 mW when thermal neutron flux rate is 6.9 × 1014 cm-2 · s-1. The small signal gain at 1.73 μm by the Rigrod analysis method is to be 0.24%-cm"1, and the saturation intensity is fitted to be 36 W/cm2.     

Measurement of tritium production rate distribution for a fusion-fission hybrid conceptual reactor

A fusion-fission hybrid conceptual reactor is established. It consists of a DT neutron source and a spherical shell of depleted uranium and hydrogen lithium. The tritium production rate (TPR) distribution in the conceptual reactor was measured by DT neutrons using two sets of lithium glass detectors with different thicknesses in the hole in the vertical direction with respect to the D~+ beam of the Cockcroft-Walton neutron generator in direct current mode. The measured TPR distribution is compared with the calculated results obtained by the threedimensional Monte Carlo code MCNP5 and the ENDF/B-Ⅵ data file. The discrepancy between the measured and calculated values can be attributed to the neutron data library of the hydrogen lithium lack S (α,β) thermal scattering model, so we show that a special database of low-energy and thermal neutrons should be established in the physics design of fusion-fission hybrid reactors.     

Minimization of Entropy Generation Rate in Hydrogen Iodide Decomposition Reactor Heated by High-Temperature Helium

The thermochemical sulfur-iodine cycle is a potential method for hydrogen production, and the hydrogen iodide (HI) decomposition is the key step to determine the efficiency of hydrogen production in the cycle. To further reduce the irreversibility of various transmission processes in the HI decomposition reaction, a one-dimensional plug flow model of HI decomposition tubular reactor is established, and performance optimization with entropy generate rate minimization (EGRM) in the decomposition reaction system as an optimization goal based on finite-time thermodynamics is carried out. The reference reactor is heated counter-currently by high-temperature helium gas, the optimal reactor and the modified reactor are designed based on the reference reactor design parameters. With the EGRM as the optimization goal, the optimal control method is used to solve the optimal configuration of the reactor under the condition that both the reactant inlet state and hydrogen production rate are fixed, and the optimal value of total EGR in the reactor is reduced by 13.3% compared with the reference value. The reference reactor is improved on the basis of the total EGR in the optimal reactor, two modified reactors with increased length are designed under the condition of changing the helium inlet state. The total EGR of the two modified reactors are the same as that of the optimal reactor, which are realized by decreasing the helium inlet temperature and helium inlet flow rate, respectively. The results show that the EGR of heat transfer accounts for a large proportion, and the decrease of total EGR is mainly caused by reducing heat transfer irreversibility. The local total EGR of the optimal reactor distribution is more uniform, which approximately confirms the principle of equipartition of entropy production. The EGR distributions of the modified reactors are similar to that of the reference reactor, but the reactor length increases significantly, bringing a relatively large pressure drop. The research results have certain guiding significance to the optimum design of HI decomposition reactors.     

Multi-Objective Optimization of Braun-Type Exothermic Reactor for Ammonia Synthesis

The exothermic reactor for ammonia synthesis is a primary device determining the performance of the energy storage system. The Braun-type ammonia synthesis reactor is used as the exothermic reactor to improve the heat release rate. Due to the entirely different usage scenarios and design objectives, its parameters need to be redesigned and optimized. Based on finite-time thermodynamics, a one-dimensional model is established to analyze the effects of inlet gas molar flow rate, hydrogen–nitrogen ratio, reactor length and inlet temperature on the total entropy generation rate and the total exothermic rate of the reactor. It’s found that the total exothermic rate mainly depends on the inlet molar flow rate. Furthermore, considering the minimum total entropy generation rate and maximum total exothermic rate, the NSGA-II algorithm is applied to optimize seven reactor parameters including the inlet molar flow rate, lengths and temperatures of the three reactors. Lastly, the optimized reactor is obtained from the Pareto front using three fuzzy decision methods and deviation index. Compared with the reference reactor, the total exothermic rate of the optimized reactor is improved by 12.6% while the total entropy generation rate is reduced by 3.4%. The results in this paper can provide some guidance for the optimal design and application of exothermic reactors in practical engineering.     

ADS堆功率控制研究及其在DCS系统的实施

研究了基于加速器束流强度调节来控制中国加速器驱动嬗变研究装置(CiADS)次临界堆功率的方法.束流强度的调节是通过比较堆功率的测量值和设定值,由PID(比例-积分-微分)控制器自动控制可调光阑的孔径大小完成的.为了评估所提出的自动控制方法,基于点堆动力学方程建立了CiADS次临界堆堆芯模型.基于CiADS堆芯模型的仿真...     

行波堆深燃耗的计算特点

行波堆属于新概念堆型,卸料燃耗深度可达400 GWd/tHM,是现有快堆的3~4倍、压水堆的6~8倍,较高的卸料燃耗深度对堆芯物理分析工具计算正确性提出挑战。基于此,以KYLIN-1程序为基础,从能谱、裂变产物核素重要性、燃耗计算误差累积等方面探究行波堆深燃耗计算特点。对典型行波堆六角形组件分析结果表明:低富集度铀组件寿期初、末能谱差别较大,采用单一权重谱制备的多群截面库用于其燃耗计算时,无限增殖系数偏差较大;为保证行波堆深燃耗计算的正确性,燃耗链应包含重要的70种裂变产物核素;行波堆深燃耗计算时,由于燃耗步增多累积的误差较小,无限增殖系数偏差每燃耗步约为0.001%。     

散射中子对超瞬发临界系统动态行为的影响北大核心CSCD

在点反应堆理论的基础上,建立了研究散射中子影响超瞬发临界系统动态行为的模拟计算方法,利用CFBR-Ⅱ堆的脉冲实验验证了该方法的正确性。通过分析计算表明,在超瞬发临界状态,散射中子的影响包括增加反应性、使脉冲波形后沿展宽和增加脉冲裂变产额。建立的模拟计算方法为预测脉冲堆外各种物体产生的散射中子的动力学效应提供了途径,对提高脉冲堆的核安全有应用价值。     

超临界水冷堆中子能谱计算及安全性分析

超临界水堆是国际第Ⅳ代核能系统论坛推荐的六种第Ⅳ代核电反应堆堆型之一,与现有的轻水堆相比,具有热效率高、系统结构简单、造价低等优点。建立了MCNP程序下的超临界水堆堆芯物理计算模型,解决了燃料组件几何结构过于复杂精细难以建模的技术难题;考虑了堆芯轴向冷却剂密度的不均匀分布,计算并分析各区域的中子能谱分布;对失水事故下的超临界水冷堆安全性进行了分析,研究了不同区域冷却剂丢失程度对反应性及有效增殖系数的影响,表明所设计堆型具有较高的安全性;分析处理失水事故的应对措施,验证了使用注入硼水措施处理超临界水冷堆失水事故的可行性。     

混合堆第一壁中子辐照损伤模拟

利用蒙特卡罗程序和辐照损伤程序,通过构建模型,对常用的第一壁材料W,Fe,Be的中子辐照造成的离位损伤、裂变气体产生量进行了模拟计算,结果表明,混合堆与纯聚变堆相比,可以明显降低对第一壁材料的损伤要求。在W,Fe,Be三种材料之中,对于纯聚变堆来说,Be的离位损伤最小;对于混合堆来说,W的离位损伤、裂变气体产生量最低。从中子辐照损伤的角度来说,Be更适宜作纯聚变堆的第一壁材料,而W则更适宜作混合堆的第一壁材料。     

Comparison of two different ultrasound reactors for the treatment of cellulose fibers

The pulp and paper industry is in continuous need for energy-efficient production processes. In the refining process of mechanical pulp, fibrillation is one of the essential unit operations that count for up to 80% of the total energy use. This initial study explores the potential and development of new type of scalable ultrasound reactor for energy efficient mechanical pulping. The developed reactor is of continuous flow type and based on both hydrodynamic and acoustic cavitation in order to modify the mechanical properties of cellulose fibers. A comparison of the prototype tube reactor is made with a batch reactor type where the ultrasonic horn is inserted in the fluid. The pulp samples were sonicated by high-intensity ultrasound, using tuned sonotrodes enhancing the sound pressure and cavitation intensity by a controlled resonance in the contained fluid. The resonant frequency of the batch reactor is 20.8 kHz and for the tube reactor it is 22.8 kHz. The power conversion efficiency for the beaker setup is 25% and 36% in case of the tube reactor in stationary mode. The objective is to verify the benefit of resonance enhanced cavitation intensity when avoiding the effect of Bjerkenes forces. The setup used enables to keep the fibers in the pressure antinodes of the contained fluid. In case of the continuous flow reactor the effect of hydrodynamic cavitation is also induced. The intensity of the ultrasound in both reactors was found to be high enough to produce cavitation in the fluid suspension to enhance the fiber wall treatment. Results show that the mechanical properties of the fibers were changed by the sonification in all tests. The continuous flow type was approximately 50% more efficient than the beaker. The effect of keeping fibers in the antinode of the resonant mode shape of the irradiation frequency was also significant. The effect on fiber properties for the tested mass fraction was determined by a low-intensity ultrasound pulse-echo based measurement method, and by a standard pulp analyzer.     

Short-time reactor neutron irradiation of YSZ prepared using reactive calcination method

The present work is devoted to study the short-time reactor neutron irradiation of yttria stabilised zirconia (YSZ) at 315 K. The samples were prepared by the reactive calcination method and characterised by X-ray diffraction (XRD) analysis and scanning electronic microscope. The prepared samples were irradiated by reactor neutrons at different exposure times and investigated by XRD analysis. The results obtained show good radiation resistance of YSZ to reactor neutron irradiation.     

海洋条件下自然循环铅铋反应堆偏环运行特性分析

基于二次开发RELAP5/MOD3.1程序,分析了典型海洋条件下的10 MW自然循环铅铋反应堆偏环运行特性。分析结果表明:反应堆在倾斜条件下偏环运行时,其系统参数对倾角变化敏感性较弱;起伏条件下,偏环运行导致流量的波动幅度降低为9%,出口温度降低约16 K。起伏幅度越大、流量波动越剧烈;起伏周期越大、流量震荡越明显,但影响效果也在减弱;摇摆条件下,堆芯流量、出口温度降低,反应堆引入更高的安全裕量;摇摆幅度越大、摇摆周期越小,流量波动幅度越大,且堆芯出口温度对周期变化敏感性明显高于摇摆幅度变化。