反应堆生产放射性同位素热源材料及其应用

可用于深空探测等领域的放射性同位素温差发电器利用半导体热电元件直接将放射性同位素的衰变热转化为电能.目前所使用的热源材料--放射性同位素~(238)Pu具有半衰期适中、热功率密度较高、α衰变易于辐射防护等特点,已获得较为广泛的应用.本文简要介绍利用反应堆生产~(238)Pu的途径以及分离、纯化过程.     

空间放射性同位素电池发展回顾和新世纪应用前景

迄今为止,美俄两国已向空间发射了80多台空间核电源(包括同位素电池和反应堆电源)。重点回顾了20世纪放射性同位素电池的研发历史和空间发射现状;概括介绍了目前放射性同位素温差发电器(RTG)业已达到的技术水平和提高热电转换效率的最近动向;综述了美国、俄罗斯和欧洲航天局在21世纪初期(20001/2015)使用RTG的空间和太阳系探索计划,展现了RTG的广阔应用前景。     

陆地用60W级241AmO2放射性同位素温差发电器的输出电性能计算及安全性分析

放射性同位素温差发电器(radioisotope thermoelectric generator, RTG)具有寿命长、环境适应性强等优点,可广泛应用于海、陆、空中的复杂场景。其中,为陆地设备供电是RTG的一个重要工程应用领域。²⁴¹AmO₂由于具有半衰期长,获取渠道广泛,剂量率低等优点,可作为陆地用RTG能源供给的来源之一。本研究设计一款60 W级²⁴¹AmO₂驱动放射性同位素温差发电器,并基于ANSYS有限元分析软件,计算其在陆地中不同环境温度下应用时的电性能和安全性。计算结果显示,环境温度影响²⁴¹AmO₂-RTG的最大输出功率和温度分布,当环境温度为-60～50℃时,其最大输出功率最低为66.0 W,最高可达75.7 W,源芯最高温度为789℃,热电模块热端最高温度为717℃。输出电性能和源芯温度满足设计指标及安全需求。     

具有独特用途的放射性同位素电池

放射性同位素电池是20世纪60年代发展起来的一种新型电源。由于它具有寿命长、工作可靠、对环境适应性强、不需经常维护、结构紧凑、比容量高等优点,因而在空间、陆地海上、海底以及医学领域都有独特的用途。本文分析了热电型放射性同位素电池的特点、基本原理、主要构成,介绍了热电型放射性同位素电池在空间地球卫星、月面试验站、外层星际探测以及在地面、海下、医学等方面的广泛应用,并展望了放射性同位素电池在21世纪的发展应用前景。     

粉末冶金法制备Si80Ge20B1.2合金及其热电性能

放射性同位素电池(Radioisotope thermoelectric generator,RTG)在深空探测中发挥着不可替代的作用。基于硅锗合金制备的温差发电器是RTG的核心部件,硅锗合金的热电性能对RTG的性能有重要影响。硅锗合金的热电性能和其制备工艺、杂质掺杂等因素密切相关,因此需要对其制备工艺研究与优化。本文采用熔炼和热压烧结制备了P型Si₈₀Ge₂₀B_1.2合金,研究了热压烧结工艺参数(热压温度、热压压力、保温时间)对Si₈₀Ge₂₀B_1.2合金密度的影响,对Si₈₀Ge₂₀B_1.2合金进行了物相结构分析、微观组织分析,并对其热电性能进行了测试。结果表明:1 703 K下熔炼2 h后硅和锗可以形成固溶体,热压烧结工艺参数中,热压温度对Si₈₀Ge₂₀B_1.2合金密度影响更为明显;热压温度1 523 K、热压压力60...     

温差发电器及其在航天与核电领域的应用

概要介绍了温差发电器的基本原理.半导体温差电元件可将放射性同位素的衰变热直接转换成为电能,为月球表面科学试验装置、外层空间探测器等提供电源;也可将反应堆的余热转换为电能,为事故后监测仪表提供可靠的电源保障.     

再入过程中的同位素热源可靠性评估

本文综合考虑微观组织不均匀性等材料的内在分散性,以及载荷历程、工作环境等外在分散性的影响,针对放射性同位素热源（RHU）产品结构特点,选用基于随机有限元法的应力-强度干涉模型,采用解析法与蒙特卡罗法相结合的方式,在有限的试验规模下,定量评价了某型RHU在再入过程中经历一系列环境载荷后的可靠性水平。 利用本文所述方法计算得到：该型RHU在95%置信度下的可靠度置信下限为0.999 989,达到了一般探测器零部件级产品的可靠性评估精度要求,这表明本文所述方法实用、可靠,在RHU的可靠性评估、指导RHU的可靠性设计、降低评估成本方面具有很高的实用价值。     

同位素应用的现状和新进展

同位素技术是一门传统学科,19世纪末,贝克勒尔发现天然放射性,尤其是发现镭后,放射性同位素技术就迅速得到了应用,但是受同位素制备能力的限制,该技术发展十分缓慢。20世纪50年代以后,随着放射性同位素制备能力的提高,同位素应用得到了快速发展,被广泛应用到核仪表、辐照加工、癌症治疗、辐射育种等领域。21世纪,随着同位素分析测量技术、生物技术及半导体技术的进步,同位素应用取得了较大进展,同位素在经济建设、国防建设和科学研究中的应用十分广泛。本文重点介绍同位素在工业、农业、医疗、环境和科研等领域中的主要应用及最新进展。     

中子核数据评价现状和发展

评述了国际、国内核数据评价的现状和发展，对我国核数据评价的发展提出了看法。     

核燃料水法后处理现状和展望

本文评论了世界各国乏燃料后处理技术。后处理能力在目前和不久将来不能满足核能的发展需要,它在燃料循环中占有重要的地位。普雷克斯流程不仅对于轻水堆燃料,而且对快中子增殖堆燃料后处理然是一种主要流程。近期后处理研究和发展的重点在于使流程最佳化,并引入新技术,尤其是U(Ⅳ),电解氧化还原,硝酸羟胺还原和亚硝气氧化等无盐过程。当处理高燃耗的乏燃料时,应采取特别措施,以避免造成溶剂的严重辐解和钚的临界问题。氚在流程中必须控制,并限定在一定区域,使其废液体积尽量减小。     

生物剂量学的研究现状和发展动向

本文对现在的或现在认为有发展前景的几种生物剂量测定方法进行了比较，包括染色体畸变、荧光原位杂交、微核、早熟染色体凝集以及二种体细胞突变；着重对它们在辐射事故剂量估计中的实用性作了评估。     

我国电磁辐射污染的法律对策初探

随着电子技术的广泛应用,电磁辐射已成为我国城乡日益严重的重要污染源.本文分析了电磁辐射污染的特点及我国电磁辐射污染的现状,指出了我国电磁辐射污染防治法律的不健全及其原因.在此基础上提供了相应的法律对策,即严格遵守现有立法、尽快建立相关的电磁辐射国家标准体系、加强电磁辐射地方立法、条件成熟时制定<中华人民共和国电磁辐射污染防治法>;并提出了制定该法的基本思路.     

蒸汽发生器给水系统中汽泡的形成与溃灭

文章对蒸汽发生器给水系统中由于蒸汽泡的溃灭而造成的水锤现象作了分析。根据实验,用液面的波动、变质量水柱的加速运动和孤立蒸汽泡的溃灭等三个模型描述了汽泡的形成与溃灭。计算结果和国外某些核电站事故分析中的估算值相当接近。     

Feasibility of the recent Russian nuclear electric propulsion concept: 2010

The paper introduces recent Russian nuclear electric propulsion (NEP) concept for space exploration. The concept advantages are listed along with future missions. The current development status for the two main enabling technologies is presented and the feasibility analysis of the up-to-date experience is performed. The main features of NEP concept are discussed. Revision of these features and available technologies demonstrates that the NEP concept is a logical continuation of the previous efforts by the former Soviet Union. Because no breakthrough technologies are needed for NEP development while the existing technologies only need to be adapted to the megawatt (MW) class NEP the development is considered technically feasible, low risk program likely to succeed unless cancelled by the listed non-technical reasons. Successful NEP space vehicle development is going to bring practical space exploration of solar system to the new level as well as require supplementary payload program, supporting monitoring and communication radar networks. Nuclear safety during future NEP missions can be ensured by adherence to the United Nations guidelines in the same way it was done during the Soviet Topaz Nuclear Power System (NPS) missions.     

Design evaluation of emergency core cooling systems using Axiomatic Design

In designing nuclear power plants (NPPs), the evaluation of safety is one of the important issues. As a measure for evaluating safety, this paper proposes a methodology to examine the design process of emergency core cooling systems (ECCSs) in NPPs using Axiomatic Design (AD). This is particularly important for identifying vulnerabilities and creating solutions. Korean Advanced Power Reactor 1400 MWe (APR1400) adopted the ECCS, which was improved to meet the stronger safety regulations than that of the current Optimized Power Reactor 1000 MWe (OPR1000). To improve the performance and safety of the ECCS, the various design strategies such as independency or redundancy were implemented, and their effectiveness was confirmed by calculating core damage frequency. We suggest an alternative viewpoint of evaluating the deployment of design strategies in terms of AD methodology. AD suggests two design principles and the visualization tools for organizing design process. The important benefit of AD is that it is capable of providing suitable priorities for deploying design strategies. The reverse engineering driven by AD has been able to show that the design process of the ECCS of APR1400 was improved in comparison to that of OPR1000 from the viewpoint of the coordination of design strategies.     

Variations of a passive safety containment for a BWR with active and passive safety systems

The paper presents variations of a certain passive safety containment for a near future BWR. It is tentatively named Mark S containment in the paper. It uses the operating dome as the upper secondary containment vessel (USCV) to where the pressure of the primary containment vessel (PCV) can be released through the upper vent pipes. One of the merits of the Mark S containment is very low peak pressure at severe accidents without venting the containment atmosphere to the environment. Another merit is the capability to submerge the PCV and the reactor pressure vessel (RPV) above the core level by flooding water from the gravity-driven cooling system (GDCS) pool and the upper pool. The third merit is robustness against external events such as a large commercial airplane crash owing to the reinforced concrete USCV. The Mark S containment is applicable to a large reactor that generates 1830 MW electric power. The paper presents several examples of BWRs that use the Mark S containment. In those examples active safety systems and passive safety systems function independently and constitute in-depth hybrid safety (IDHS). The concept of the IDHS is also presented in the paper.