Investigation of the hydrogen production of a laser FUSION driver thorium breeder using various coolants

In this present work, hydrogen production and neutronic calculations of a Laser Inertial Confinement Fusion Fission Energy (LIFE) driven thorium breeder using various coolants have been investigated. In the neutronic calculations for fusion driver power of 500 MW_th has been examined with MCNP code. The 95 vol% Flibe or natural lithium 5 vol% TRISO coated ThC fuels have used in the neutronic calculations. Tritium breeding ratio (TBR) has been calculated as 1.08 and 1.19, respectively, for Flibe and natural lithium coolants. The energy multiplication values have been computed as 3.17 and 1.62, respectively, for these coolants. The burnup values with flibe and natural lithium have been obtained as 6 GWd/tM and 22 GWd/tM over 11 and 23 years, respectively. Also, the hydrogen production of a laser fusion driver thorium breeder using steam methane reforming (SMR), high temperature electrolysis (HTE) and sulfur-iodine (S–I) thermochemical water splitting processes have been performed. The highest hydrogen production values with flibe coolant of SMR method have been obtained as ~200 kg/s over 11 years.     

A compact and high-efficiency electrified reactor for hydrogen production by methane steam reforming

An electrified reactor driven by renewable electricity, substituting conventionally fired reactors, will reduce CO₂ and provide a compact manner for hydrogen generation. Herein, we proposed a high-efficiency electrified reactor based on a high-temperature heat pipe (HTPR). The start-up of the HTPR powered by electricity was firstly evaluated, showing a start-up duration of 250 s and maintaining significant temperature uniformity of 96.7%. Then, the feasibility and performance of the HTPR were validated by experiments. The methane conversion and hydrogen mole fraction were 80.0% and 70.5% at a steam to carbon ratio of three, respectively. Finally, the reaction performance under different operating conditions was simulated. The methane conversion and the hydrogen mole fraction were attenuated with the increase in flow rate, and improving catalyst porosity is beneficial for the heat transfer between catalysts and gases. This study serves as a framework for designing an electrified reactor for endothermic reactions.     

Best Estimated and Conservative Analyses for a Feedwater Pipe Break Accident of an Integral Type Reactor

An integral type reactor, which is an innovative design to achieve a high degree of safety, is currently being developed at the Korea Atomic Energy Research Institute. A feedwater pipe break accident is one of the most important accidents regarding the safety of an integral type reactor. A best estimated calculation, a conservative calculation, and a parameter study for a feedwater pipe break have been carried out. The sensitivity analysis in this paper performed is to establish the parameters which greatly affect the feedwater pipe break accident. A power level, an initial system pressure, a moderator reactivity coefficient and a break size are the major parameters which maximize a system pressure. The important function that must operate following a feedwater pipe break accident is an opening of the pilot operated safety relief valves, and an initiation of the passive residual heat removal system. The integral reactor safety systems function properly and thus secure the reactor to a safe condition with respect to the safety parameters.     

Transient numerical modeling and model predictive control of an industrial-scale steam methane reforming reactor

A steam methane reforming reactor is a key equipment in hydrogen production, and numerical analysis and process control can provide a critical insight into its reforming mechanisms and flexible operation in real engineering applications. The present paper firstly studies the transport phenomena in an industrial-scale steam methane reforming reactor by transient numerical simulations. Wall effect and local non thermal equilibrium is considered in the simulations. A temperature profile of the tube outer wall is given by user defined functions integrated into the ANSYS FLUENT software. Dynamic simulations show that the species distribution is closely related to the temperature distribution which makes the temperature of the reactor tube wall an important factor for the hydrogen production of the reformer and the thermal conductivity of the catalyst network is crucial in the heat transfer in the reactor. Besides, there exists a delay of the reformer's hydrogen production when the temperature profile of the tube wall changes. Among inlet temperature, inlet mass flow rate and inlet steam-to-carbon (S/C) ratio, the mass flow rate is the most influencing factor for the hydrogen production. The dynamic matrix control (DMC) scheme is subsequently designed to manipulate the mole fraction of hydrogen of the outlet to the target value by setting the temperature profile trajectory of the reforming tube with time. The proportional-integral control strategy is also studied for comparison. The closed-loop simulation results show that the proposed DMC control strategy can reduce the overshoot and have a small change of the input variable. In addition, the disturbances of feed disturbance can also be well rejected to assure the tracking performance, indicating the superiority of the DMC controller. All the results give insight to the theoretical analysis and controller design of a steam methane reformer and demonstrate the potential of the CFD modeling in study the transport mechanism and the idea of combining CFD modeling with controller design for the real application.     

SMART： The First Licensed Advanced Integral Reactor

SMART （system-integrated modular advanced reactor） is a small-sized advanced integral reactor with a rated thermal power of 330 MW. It can produce 100 MW of electricity, or 90 MW of electricity and 40,000 t of desalinated water concurrently, which is sufficient for 100,000 residents. SMART technology is a sensible mixture of new innovative design features and proven technologies through a PWR. The enhancement of safety and reliability is realized by incorporating inherent safety features and reliable passive safety systems. The improvement in the economics is achieved through system simplification, component modularization, construction time reduction, and increased plant availability. All technologies and design features implemented into SMART have been proven in industries and/or qualified through the SMART design verification program including comprehensive test and experiments. The full scope of the safety analyses carried out to confirm that the inherent safety-improvement design characteristics and safety systems of SMART ensure reactor safety. After a thorough licensing review, SDA （standard design approval） for SMART was granted on July 4th, 2012 by the Korea NSSC （Nuclear Safety and Security Commission）. This marks the first license for an integral-type reactor in the world. This paper presents the SMART characteristics, safety features and technology validation. The licensing process of SMART is also described.     

预转化技术在制氢装置的应用

介绍了预转化技术在中海炼化惠州炼油分公司制氢装置的成功应用、预转化技术较传统的一段式转化炉技术的技术优势及经济优势、庄信万丰（Johnson Matthey Catalysts,简称JMC）预转化催化剂特点以及预转化反应器开车投用过程,分析了其应用过程中涉及到的问题,如选择合适开停工流程和方法,降低反应操作的苛刻度,优化水碳比控制等。同时介绍了一些常见问题的处理,尽可能地维持预转化反应系统的平稳运行,降低装置运行费用,按一年运行8 400 h计,可节省燃料气成本约2 480×104 RMB$,预转化催化剂预计寿命可达4 a。     

SMR模块化运输带来的挑战

小型模块化反应堆(SMR)模块化的特点可以弥补大型核电厂建造周期长、资金压力大的缺点,且应用场景广泛,是当前各国核工业的研究热门。尽管有大量文献针对SMR的堆芯安全展开研究,但鲜有文献是关于SMR的运输安全。本文通过查阅文献并结合网上信息,从3个方面总结了SMR给运输安全领域带来的挑战,包括:大型重型模块运输、核燃料运输和装载燃料的密封堆芯运输,并给出了合理化建议。     

DZC-3000型工业称量仪抗干扰措施

为解决DZC-3000型工业称量仪在恶劣的工业环境中受到干扰问题,在分析系统可能受到供电电源、系统输入输出通道、外界对CPU干扰等各种干扰的基础上,提出了软硬件方面的各种抗干扰措施,重点分析了SMR软件抗干扰措施。当程序运行脱离正常运行流程时,使用SMR抗干扰措施可使PC进入复位入口,并从受干扰处重新按原流程运行。     

场监雷达天线座关键技术研究

场监雷达必须能够快速、实时监视机场内的目标,其数据率通常≤1 s.为实现该指标,天线必须能够实现高速水平旋转(转速通常为60 r/min),而以往的空管雷达天线座均不能满足其指标要求(转速通常为6~15 r/min).文中采用双电机与蜗轮蜗杆式减速机直连驱动设计、高速旋转天线的动平衡设计、高速旋转传动系统的浸油润滑与非接触式旋转密封设计等关键技术以及远程监测天线座内油位和油温、远程监测天线座水平状态、远程进行温控等辅助设计,完成了一种具有可高速水平旋转、可远程监测运行状态、可靠性高的场监雷达天线座研制工作.该研制成果已应用于机场场面监视雷达且无故障运行时间大于17520 h.     

SMR路由协议的改进与仿真分析

在Ad Hoc网络中,分裂多径路由SMR协议存在数据分割传输效率低与路由维护中路由发现条件不合理的问题。为此,提出一种改进的路由协议P-SMR。该协议采用以时延作为路径负载影响因子的数据分配方法来提高传输效率,运用判断路径断开条数和路径生存时间的方法作为路由发现的条件。仿真结果表明,与SMR和DSR协议相比,P-SMR协议可降低平均端到端传输延时和路由开销,并能提高分组投递率。