Calculations Energy of the (<i>nl</i>²) ¹<i>L^π</i>Doubly Excited States of Two-Electron Systems via the Screening Constant by Unit Nuclear Charge Formalism

In this work, the total energies of doubly excited states (ns2) 1Se, (np2) 1De, (nd2) 1Ge, (nf2) 1Ie, (ng2) 1Ke, and (nh2) 1Me of the helium isoelectronic sequence with Z ≤ 10 are calculated in the framework of the variational method of the Screening Constant by Unit Nuclear Charge (SCUNC). These calculations are performed using a new wavefunction correlated to Hylleraas-type. The possibility of using the SCUNC method in the investigation of high-lying Doubly Excited States(DES) in two-electron systems is demonstrated in the present work in the case of the (nl2) 1Lπ doubly excited states, where accurate total energies are tabulated up to n = 20. All the results obtained in this paper are in agreement with the values of the available literature and may be useful for future experimental and theoretical studies on the doubly excited (nl2) 1Lπ states of two-electron systems.

China Starts Studies into New Systems of Nuclear Energy

With the support of the Ministry of Science and Technology (MOST), scientists from the Chinese Academy of Atomic Energy and the Chinese Academy of Sciences (CAS) formally kicked off a new project to look into clean nuclear energy on September 27th in Beijing. The study, known as the accelerator-driven system of clean

Sustainability-oriented prioritization of nuclear fuel cycle transitions in China:a holistic MCDM framework under uncertainties

A sustainability-oriented assessment of the nuclear energy system can provide informative and convincing decision-making support for nuclear development strategies in China.In our previous study,four authentic nuclear fuel cycle(NFC)transi-tion scenarios were proposed,featuring different development stages and exhibiting distinct environmental,economic,and technical characteristics.However,because of the multiple and often conflicting criteria embedded therein,determining the top-priority NFC alternative for a sustainability orientation remains challenging.To address this issue,this study proposed a novel hybrid multi-criteria decision-making framework comprising fuzzy AHP,PROMETHEE GAIA,and MOORA.Initially,an improved fuzzy AHP weighting model was developed to determine criteria weights under uncertainty and investigate the influence of various weight aggregation and defuzzification approaches.Subsequently,PROMETHEE GAIA was used to address conflicts among the criteria and prioritize alternatives on a visualized k-dimensional GAIA plane.As a result,the alternative for direct recycling PWR spent fuel in fast reactors is considered the most sustainable.Furthermore,a sensitivity analysis was conducted to examine the influence of criteria weight variation and validate the screening results.Finally,using MOORA,some significant optimization ideas and valuable insights were provided to support decision-makers in shaping nuclear development strategies.

Understanding Accelerator Driven System (ADS) Based Green Nuclear Energy: A Review

This paper reflects the scopes of accelerator driven system (ADS) based nuclear energy, as a reliable source of electric energy generation, comparing to the other existing non-renewable and renewable sources. There are different limitations in the use of every source of electric energy but in consideration of minimum environmental impact, exclusively inherently low greenhouse gas (GHG) emission, and also, high life time with maximum power production efficiency, nuclear would be the best choice. From this study it was found that several difficulties involved in the ADS based energy production, more specifically, difficulties regarding the target parameters, coding system, waste management, etc. Hence suggestions from this study points out that if it is possible to ensure more energy efficient production of enriched uranium, improved nuclear fuels and reactors that allow greater utilization, extended life times for nuclear power plants (NPPs) that reduce the need to build new facilities, improved coding system capable of minimizing the discrepancy between theoretical and experimental calculation of spallation products, improved data library with sufficiently available high energy nuclear data to perform a better coding analysis, and finally, considering the environmental safety if the disposal of the radioactive wastes could manage more effectively, nuclear energy would then play a significant role in minimizing future energy crisis worldwide as well as to save our loving green earth.

The Role of Nuclear Power from a System Engineering Standpoint

This work proposed the application of system engineering methods to identify organizations vital for society, seeking development and well-being. System engineering requires the identification of blocks (or systems), identification of their service functions, identification of states, identification of required quality and identification of constraints. Analyzing modern societies, vital functions were identified and countries behavior was modeled, identifying their states. In this context, nuclear power was found to be fundamental for development and defense because of its inherent advantages for military naval purposes at war. Another striking conclusion is that nuclear power is the best solution for country energy security, more than to avoid climate changes, but to help the nation to resist climate changes. A solution to mitigate the high overnight costs of nuclear power was also proposed. It was demonstrated qualitatively that the adoption of dual purpose mobile nuclear power plants military performances, economic development and risks management.

无人机载CeBr3航空监测系统无限大面源探测能力研究

在核设施发生重大事故后,快速获取事故应急区内的辐射水平,对后续应急决策及救援、保护公众免受辐射危害具有至关重要的意义,核应急航空辐射监测是核应急早期快速获取辐射水平的重要技术手段和方法之一,因此核工业航测遥感中心自主研发了无人机载CeBr3航空监测系统。为准确评估该监测系统的探测能力,文章使用蒙特卡罗方法对该监测系统进行了建模,并通过60Co点源对模型的准确性进行了验证。在此基础上,采用全能谱分析、蒙特卡罗及实验相结合的方法获得监测系统对天然辐射单位能谱,并以核事故后地面受到一个新的137Cs放射性沉降场景为例,计算监测系统在不同测量条件下(天然辐射本底、晶体体积、测量高度)对无限大137Cs面源的探测效率及最小可探测活度浓度。通过模拟及计算监测系统对天然辐射本底及核应急人工放射性核素的单位能谱,准确评估了自研的无人机载CeBr3核应急航空监测系统的探测能力,为后续利用该监测系统开展核与辐射航空监测可提供重要理论依据及数据支撑。

核岛冷链通风空调系统性能优化研究

核岛冷链通风空调系统的设计存在余量值过大、运行能耗高、调节控制笨重等问题。为了降低核电的成本,本文基于“华龙一号”某厂房实际通风空调系统,建立了主要能耗设备的数学模型,确定了系统节能优化目标函数和约束条件,使用遗传算法研究了通风空调系统节能运行的优化效果。分别计算了2种优化方案在负荷率变化和高温与常温末端负荷比不同时,系统整体及各设备能耗情况。结果表明:单台冷水机组运行,高温与常温末端串联的系统形式节能率为14.1%,但随着末端负荷比的增大,节能率降低;单台冷水机组运行,高温与常温末端串联、高温末端额外增加高温冷水机组的系统形式在负荷比为2时节能率为17.2%,节能效果优于方案1的12.2%。

月面科研站核反应堆电源系统发展现状

伴随着月球科考与开发的全面展开,月面科研站的工程建设已逐渐提上日程,为月面科研站提供可靠、持续、长寿命的电力供应是先决条件。核反应堆电源系统,因适应月球各纬度地区和长昼夜交替条件,具有持续提供高功率输出、高能量密度和长寿命特点,被视为月面科研站能源系统主电源最有潜力的解决方案。本文首先总结了人类探月历史的演化,紧接着介绍了月面科研站能源系统面临的环境条件以及能源需求,然后介绍了月面核反应堆电源系统的结构和工作原理,并梳理了国内外当前各种月面科研站核反应堆电源系统的概念设计和开发阶段情况,最后对未来月面用核反应堆电源系统的发展前景进行了展望,并针对技术突破和应用需求提出了建议。

考虑源网协同支撑作用的含新能源电力系统网架重构决策优化方法

面对复杂多变的国际形势和日益增多的极端事件,研究新能源高比例接入下的系统恢复方案,对完善新型电力系统安全防御体系具有重要意义。在此背景下,提出一种含新能源电力系统网架重构决策优化方法。首先,基于核密度法对新能源出力不确定性进行分析建模;其次,考虑新能源并网和运行对网架强度的要求,实现了新能源多场站短路比约束的线性化建模;在此基础上,建立了能协同新能源、储能、常规机组和输电网络恢复的网架重构优化模型,并提出双层优化策略以提升模型求解效率。基于新英格兰10机39节点系统的算例结果验证了所提方法的有效性。

焓差控制法在某核电厂空调系统中的应用

介绍了焓差控制法在核电厂空调系统中的应用:在满足系统功能的前提下,通过优化送风温度范围来扩大空调系统运行工况范围以达到节能效果。介绍了系统最小新风量和冬、夏季工况点的设定,空气比焓的计算及系统控制逻辑的实现。运行结果表明,空调系统运行稳定且节能效果良好,可为核电厂空调系统应用焓差控制法提供参考。

核电工程高质量建设过程定量指标体系及评价办法

目前国内核电建设正处于蓬勃发展的时代,行业监管部门也高度强调建设期的质量对于电厂运行期的核安全的重要保障作用。为了提高项目建设质量、对标国内同行,本文依托工程项目实践和成熟的项目管理理念构建了一套指标体系,内容涵盖四大控制要素和EPC管理领域,对项目建设过程中要采取的行动进行表单化梳理,用于指导项目建设标准化高质量开展,能够定量展示项目建设水平。

核电厂通风系统运行方式优化分析

随着电力行业改革的不断深化,核电厂应不断加大技术创新和改造力度,降低厂用电率,从而降低发电成本。文章结合通风系统实际运行情况,提出了核电厂通风系统运行方式的优化策略,包括根据季节变化减少运行数量、调整房间内空调风机运行数量、提高空调温度、冬季减少蒸发冷却机组和屋顶风机运行数量、应用自动控制技术、优选非能动通风形式及加强风险预防,旨在达到预期的优化效果,在满足核电厂生产需求与保证生产活动安全的前提下,改善通风系统运行条件,最大限度地释放节能潜力。

超临界二氧化碳核能动力系统的兴起和发展

超临界二氧化碳(S-CO_(2))核能动力系统以S-CO_(2)为工质,通过直接或间接循环将核释热转换为电能或机械能。本文总结了国际上S-CO_(2)核能动力系统的概念初创、研究重启、协同创新3个历史阶段近60年的发展历程,分析了S-CO_(2)核能动力系统在核反应堆设计、材料工艺、热工流体力学、换热器、涡轮发电系统、系统运行、控制及安全策略等方面的研究现状,并提出了S-CO_(2)核能动力系统在基础研究和工程攻关中面临的技术挑战和攻关方向。目前,以中美为代表的能源强国已初步完成S-CO_(2)动力转换系统的实验室级测试,预计可在5~10年内实现中等规模工程示范甚至规模化应用。S-CO_(2)核能动力系统基本具备了走向工程的前提条件,有望引领先进核能技术变革。

Towards Safer and More Sustainable Ways for Exploiting Nuclear Power

Future electricity systems are challenged by deep decarbonization and concurrently increasing demand and there are growing concerns that renewables cannot shoulder this alone. Starting from the proven principle of diversity, we argue for keeping the nuclear option open or even for expanding its use. However, the perspectives are dim for the current technology as safety concerns and social aversion remain as fundamental problems. While looking for future revolutionary safe and more sustainable nuclear concepts we first review the main characteristics of civil nuclear energy, as well as its safety records and technical progress. We then list the key requirements for innovative nuclear systems designs which are less dependent on active safety systems and human performance as well as social stability. This allows us to provide a concept by concept comparison and assessment of existing and novel technologies and designs including different coolants and neutron spectra. The results indicate a high potential for far-reaching improvements compared to most advanced LWRs, although none of the candidate concepts meets all requirements convincingly, yet, helium cooled, small modular reactors (HTR-PM) come closest. We end by stressing the need for future research and development, and keeping human capital and know-how in nuclear energy;we call for an urgent increase in government and international RD&D funding by the order of a few hundreds of billions of USD per year, which will likely lead to breakthroughs that will restart productivity growth in severely affected stagnating modern economies.

热化学硫碘循环水分解制氢研究进展

随着化石能源日益短缺和环境污染日益严重,寻求高效、清洁、可再生能源迫在眉睫。氢能作为现代能源体系新密码,因清洁、可再生、可存储、用途广泛等优点,近年来受到广泛关注。目前制氢方式众多,但大规模、高效、低成本、绿色的制氢方式才是未来氢能经济的基础。其中,热化学硫碘循环(也称碘硫循环)水分解制氢因具备上述优点被认为是最具发展潜力的制氢方法之一。从Bunsen反应、H2SO4分解和HI分解3方面综述了热化学硫碘循环水分解制氢的基础研究情况,对目前各国已建立的硫碘循环系统进行总结,着重介绍了核能耦合硫碘循环制氢流程的最新进展。从经济、环保和安全方面对目前核能耦合硫碘制氢进行分析讨论,以期为未来研究和发展提供新思路。针对Bunsen反应部分,寻找一种高效分离反应物的新方法至关重要;而对H2SO4分解和HI分解部分,现阶段主要研究仍集中在开发稳定、高效、低成本的催化剂。经过几十年研究,热化学硫碘循环水分解制氢技术已取得长足发展。在实际产氢中,苛刻的高温高腐蚀环境、复杂的耦合流程是限制其规模化、工业化的主要原因,开发由工业结构材料制成的耐腐蚀和耐热系统,继续对耦合流程进行优化和模拟是未来热化学硫碘循环水分解制氢技术的发展方向。

当今核能发展的机遇与挑战

碳达峰、碳中和目标的提出对我国核能发展提出新的要求,如何正确理解核能在未来新型能源体系下扮演的角色和作用,是当今核能行业需要迫切回答的问题。该文面向“双碳”目标下我国新型能源系统建设需求,分析核能发展的必要性和面临的挑战,指出核能因其技术成熟、供热稳定、绿色环保等优点,是实现以风能、太阳能为基础的新型电力系统的安全稳定基荷电源,发展核能是助推实现“双碳”目标的重要举措之一,是历史的必然选择。同时,文章指出发展核能所要面临的一系列挑战,为我国建设核能产业、助力双碳目标实现提供思路和方向。

月面科研站分布式能源系统研究

月面科研站是月球科研站的月面探测集群,由多个任务单元组成,包括月面的指挥控制中枢、月面/月地通信系统、月面能源系统以及各个探测任务单元。能源系统是月面科研站的重要组成部分,为了高效地配置、调度和运维能源系统,提出了昼间以光伏发电为主、夜间核电系统进行能源补充的分布式能源系统方案。对月面科研站的分布式能源系统开展研究,分析了各个任务平台的发电能力、分析科研站的用电需求和各种载荷用电特点,对月面科研站分布式能源系统的体系构架进行了对比分析,优选星形构架的分布式科研站能源系统方案。提出10 kW级长期载荷供电方案和系统构成,对月面科研站能源系统的关键技术和建造方式进行分析,能够应用于后续月面科研站的能源系统建设和组织运维。

基于实物期权的先进核能系统投资价值评估模型研究

先进核能系统能有效解决核电的铀燃料利用率低和乏燃料有效处理难等问题,研发先进核能系统投资额度大,且具有较大不确定性,科学评估先进核能系统投资价值,有助于筹措经费,提高投资者投资意愿。本研究考虑了实验研发成本、工业示范成本、商业运营成本、以及收益等不确定性因素,以Barone-Adesi Whaley(BAW)美式期权模型为基础,构造了技术价值评估方法。运用该方法评价了先进核能系统A研发与示范项目的装机规模、技术进步、不同功率情景、电价、工期延长,以及成本超支等因素对其首堆投资价值的影响。结果表明,工业示范阶段工期延长将负面影响其经济性,但当装机规模达到5GW时,会消除工期延长带来的负面影响。

中日韩民众对核电安全认知的比较分析

为了在东亚地区建立一个有效的核安全合作体系,使区域内核风险信息交流制度化,以1 563名中日韩居民为研究对象,通过问卷调查的形式对受访者进行了有关核电基本原理及风险的认知程度、对本国核电政策的接受度、对国家核安全协作问题的了解程度等调查。研究结果显示,中国、日本和韩国的首都居民对核电相关的基础知识以及对本国核电安全相关政策了解不足,其中对政府和核电运营企业有关核电安全和信息披露的信赖度不高,并且大多数受访者表示不知道中日韩核安全监管高官会,或者即使知道,也认为此机构对核电安全没有起到很好的保障作用。本研究通过问卷调查的方式,收集到了中日韩三国的首都居民对核电的了解和接受度的真实全面的数据。通过比较分析民众对核电基础知识的了解程度,对核电相关风险的认知水平,以及对本国核电政策的接受度和对东亚地区国家间核安全协作问题的态度,最终提出有助于东亚地区向更加安全的核电事业发展迈步的建议,以期有助于今后东亚地区核电安全监管体制的设计与构建。

变频技术在核岛冷冻水系统中的应用研究

核岛冷冻水系统是为核岛通风空调提供冷源的冷水系统。由于核电工艺的特殊性以及环境条件的复杂性,要求冷冻水系统具有对宽范围负荷变化的适应能力,且冷水机组和水泵的配置必须满足夏季最大负荷要求。但在实际运行中,满负荷运行时间较短,其他负荷运行时制冷能力被白白浪费,增大了电能消耗。研究将变频技术应用于核岛冷冻水系统的可行性,并分析应用变频技术的经济性,以达到核电厂节能降耗的目的。