An Anisotropic Geomechanical Model for Jointed Rock Masses at Taishan Nuclear Power Station, Southern China

An anisotropic geomechanical model for jointed rock mass is presented. Simultaneously with deriving the orthotropic anisotropy elastic parameters along the positive axis, the equivalent compliance matrix for the deflection axis orthotropic anisotropy was derived through a three- dimensional coordinate transformation. In addition, Singh＇s analysis of the stress concentration effects of intermittent joints was adopted, based on two groups of intermittent joints and a set of cross- cutting joints in the jointed rock mass. The stress concentration effects caused by intermittent joints and the coupling effect of cross-cutting joints along the deflection-axis are also considered. The proposed anisotropic mechanics parameters method is applied to determine the deformation parameters of jointed granite at the Taishan Nuclear Power Station. Combined with the deterministic mechanical parameters of rock blocks and joints, the deformation parameters and their variability in jointed rock masses are estimated quantitatively. The computed results show that jointed granite at the Taishan Nuclear Power Station exhibits typical anisotropic mechanical characteristics; the elastic moduli in the two horizontal directions were similar, but the elastic modulus in the vertical direction was much greater. Jointed rock elastic moduli in the two horizontal and vertical directions were respectively about 24% and 37% of the core of rock, showing weakly orthotropic anisotropy; the ratio of elastic moduli in the vertical and horizontal directions was 1.53, clearly indicating the transversely isotropic rock mass mechanical characteristics. The method can be popularized to solve other rock mechanics problems in nuclear power engineering.

Investigation on the seismic response of nuclear power stations with a pile-raft foundation using centrifuge tests

Research to reliably predict the seismic response of nuclear power stations with a pile-raft foundation is needed to meet the high safety requirements of nuclear power stations.In this study,a scaled superstructure with a 4×3 pile-raft foundation,which is constructed in Shanxi kaolin clay,is modelled.Accordingly,the characteristics of seismic response for nuclear power stations with a pile-raft foundation are analyzed using dynamic centrifuge tests.In particular,multiple earthquake motions with different magnitudes and frequency properties are utilized to map the relationship between structural response and properties of earthquake motions.The results show that the seismic response of the soil,raft,and structure are significantly affected by the natural frequency and magnitude of the earthquake motion.The soil surface acceleration is lower than the raft acceleration.The results provide a reliable reference to better understand the seismic response of nuclear power stations.

Phytoplankton ecology in the adjacent waters of the Daya Bay Nuclear Power Station in Guangdong in spring

The purpose of this study is to detail the ecological characteristics of phytoplankton in waters around the Daya Bay Nuclear Power Station in Guangdong (GNPS) (Fig. 1) in spring, the bloom period of algae. The collections with a small temporal scale of every three days were made during 30 cruises from March to May in 1987. Such an investigation has never been carried out before in China except that the seasonal distribution and composition of phytoplankton in these regions were reported in

Application and Innovation of Equipment Reliability Management at Nuclear Power Stations

To achieve excellent production capability and maintain high security for nuclear power stations, equipment reliability is studied as a key issue. As the main branch, equipment reliability management is considered as an effective approach to make plant management strategy and organize routine work. Some achievements on research and application of equipment reliability management at Daya Bay Nuclear Power Station are introduced in this paper. By studying and implementing 1NPO （Institute of Nuclear Power Operations） AP-913 equipment reliability process, reliability-centered maintenance （RCM）, critical component management （CCM）, and many other similar methods, equipment reliability management system has been established at Daya Bay. And by continuous effort on improving application effect of these technologies, some innovation has also been made. Some innovative products, such as iSOM Intelligent Expert System, reliability and technique centered maintenance （RtCM）, predictive maintenance system （PdM）, and so on, have been developed. Based on these achievements, Daya Bay Nuclear Power Station has achieved excellent operation performance and won several prizes in WANO （World Association of Nuclear Operators） competition every year.

Sleep and Stress of Late Middle Age Males Who Are Forced to Live in Emergency Temporary Houses and Post-Earthquake Public Houses for a Long Period Due to the Fukushima Daiichi Nuclear Power Station Accident

It has been revealed that prolonged shelter life caused by Fukushima Daiichi Nuclear Power Station accident in conjunction with the Great East Japan Earthquake influences sleep and mental health of the residents, and therefore its influence on their physical and emotional health has become a concern. Therefore, in this study, the authors aimed at clarifying actual situations of sleep and stress of middle age males living in shelters for a long period in each of emergency temporary houses and post-earthquake public houses. For 5 males who moved from emergency temporary houses to post-earthquake public houses, their objective and subjective sleep states were measured with Actigraph and PSQI, respectively. Furthermore, their objective and subjective stresses were measured with saliva stress biomarkers and GHQ28, respectively. Their data were analyzed by paired t-test. As result, in comparison between the life in the emergency temporary houses and post-earthquake public houses, significant variation was not recognized in their objective sleep states and saliva stress biomarkers though their subjective sleep and subjective stress were significantly worsened after moving to the post-earthquake public houses.

Assessment of Effects of Qinshan Nuclear Power Station on the Ecological Environment and Water Quality of its Adjacent Waters after its Running

On the basis of the data of biological and nonbiological factors collected respectively from 1989 to 1990 and from 1995 to 1996 in the waters nearby the Qinshan Nuclear Power Station, the ecological environment and water quality of the waters are analyzed and assessed in the paper. The results show: (a) the surveyed area has the typical ecological characteristics of high tidal range estuary, rich nutrients and low biological productivity, (b) tide, runoff and offshore seawater intrusion are the key factors which result in seasonal and annual changes of various biological and non-biological factors, (c) the risking of seawater eutrophication index is resulted from enormous amount of the discharges of industrial and domestic sewage, (d) because the survey area is located in a high tidal-range estuary, thermal effluent from cooling system does not induce significant temperature changes, ( e) the first stage project of Qinshan nuclear power station has no notable impacts on the ecological environment in

Study on integrated development and hybrid operation mode of nuclear power plant and pumped-storage power station

The nuclear power plant is suitable for base-load operation, while the pumped-storage unit mainly gives play to capacity benefit in the electric power system;hence, the integrated development and hybrid operation mode of the two can better meet the needs of the electric power system. This article first presents an analysis of the necessity and superiority of such mode, then explains its meaning and analyzes the working routes. Finally, it proposes the business modes as follows: low price pumping water electricity plus nuclear power in the near term;nuclear power shifted to pumped storage power participating in market competition in the middle term;and, in the long term, nuclear power shifted to pumped storage power as primary and serving as an electric power system when needed.

Property uniformity of thick nickel-based alloy plate for nuclear power steam-generator divider plate

This paper introduces a thick 690 nickel-based alloy plate produced by the former Baosteel Special Steel Co.,Ltd.used as the steam-generator divider plate in the pressurized water reactor nuclear power plant.According to the product characteristics and design requirements of the thick nickel-based alloy plate,multidimensional sampling and testing were conducted to investigate its microstructure and mechanical properties.The results show that all the property indexes of the thick hot-rolled nickel-based alloy plate meet the design requirements,and there is good uniformity in the microstructure and mechanical properties in different dimensions.These findings indicate that China has mastered the core manufacturing technology of thick nickel-based alloy plates for their use as divider plates in nuclear power steam generators.

铅基反应堆海洋核动力发展研究

铅基反应堆(铅基堆)核动力具有固有安全、小型轻量、长寿高效等突出优点,在先进海洋装备、无人潜航器、深海空间站的能源动力上应用前景广阔;在加快建设海洋强国的背景下,保障海洋能源供给成为重要的基础条件,开展铅基堆海洋核动力发展研究是推动我国海洋装备能源动力技术革新的关键内容。本文总结了海洋核动力的应用场景与发展需求,从技术特征、代表性应用、研制现状等方面系统梳理了铅基堆核动力的发展概况,凝练和剖析了包括核燃料与包壳材料、一回路关键设备、冷却剂工艺与氧测控、先进发电技术在内的铅基堆海洋核动力关键技术。立足国情研判了铅基堆海洋核动力面临的发展挑战,提出了低温铅基堆海洋核动力、高温高效铅基堆海洋核动力、一体化全自然循环铅基堆海洋核动力等可行技术路线。研究建议,强化前瞻性配套专项技术研发、加快部署装备示范工程,将铅基堆纳入重大能源战略、加快建设标准体系,设置国家级联合研发机构、构建科技创新和产业发展新模式,更好服务国家海洋战略并推动海洋核动力跨越式发展。

核电厂核安全设备运行状态监测技术研究

核电厂安全相关设备的状态可靠是电厂安全保障的核心要素,然而绝大部分核安全设备都是设计在发生基准事故期间或之后用来确保反应堆安全的,日常生产中并不运行,只能通过定期试验验证设备可用性。本文提出一种基于多元状态估计技术的核安全设备状态智能监测方法,该方法通过建立状态监测模型,可以在设备启停试验过程中实时预测参数并判断设备运行状态,预警设备的早期异常。该方法首先采集设备历史试验过程中的状态优良数据,训练监测模型来挖掘数据的关联特征;然后,在新的定期试验过程中实时采集设备运行数据,并基于训练好的模型推断各参数的实时预测值,当实测值与预测值产生过大偏差时发出预警信息。本文以某电厂某型号核安全水泵为例进行建模并验证,结果表明本文提出的监测模型可以模拟核安全设备在定期试验过程中的数据变化特性,并且可以有效监测和预警核安全设备在定期试验过程中的早期异常。

秦山核电站海域有害盐在带温核级材料表面沉积实验设计

含Cl有害盐在服役构件表面的沉积量,是影响服役构件腐蚀进程的重要因素。秦山核电站临海而建,面临含Cl有害盐沉积引起的腐蚀问题。该文通过实地环境调研,并根据调研结果开展实验室盐雾沉积实验设计,结果表明:以ASTM D1141-98(2021版)标准中的人工海水Cl元素含量为基准,将秦山核电站海域海水各化合物含量乘以4.075 26进行放大,可得到符合ASTM标准设计的盐雾沉积用有害盐模拟溶液成分。之后,该文进一步开展90℃带温核级材料表面有害盐沉积实验,探究临海服役环境下,有害盐在秦山核电站乏燃料贮罐材料(带温核级材料)表面的沉积规律,为开展实际服役环境下的核电站材料服役寿命评估、服役性能评价提供一种实验室设计思路与借鉴。

某核电工程SBO柴油发电机组设备鉴定方案研究

全厂断电(Station Block Out,SBO)柴油发电机组在全厂断电事故工况下,除作为水压试验泵的电源外,还为主控室和重要机柜间通风系统、安全壳环形空间通风系统、主泵相关电动阀门及非能动专用电源系统供电,保证控制室某些指示仪正常工作,并使单元机组运行必需的控制器可用,是核电厂的最后一道安全电源防线,其重要性不言而喻。为了确保设备的可靠性,某核电工程SBO柴油发电机组的安全分级为F-SC3(安全重要的非安全设备),且电气设备需要满足K3类鉴定要求。基于此,对某核电工程SBO柴油发电机组的鉴定要求和项目实施方案进行研究。

三维激光投影技术在核电厂施工放样中的应用

施工放样作为核电厂建造的关键基础工作,是其他施工活动的依据,其对工程质量及进度有着直接影响。目前核电建安领域主要采用全站仪进行逐点式放样的施工放样方法,该方法具有放样精度差、施工效率低和人工成本投入大等弊端。本文主要提出了应用三维激光投影技术实现核电厂快速施工放样,该方法具有批量放样和投影精度高的特点,通过核电厂施工放样可行性分析和某核电项目现场应用,并使用全站仪进行对比分析,验证了三维激光投影技术在核电厂施工放样中具有一定的应用前景。

压水堆核电厂“死管段效应”腐蚀研究及氧含量控制

国际上采用M310堆型的压水堆核电厂均存在“死管段”现象,此现象会导致管道内壁和阀门部件严重腐蚀,威胁机组的安全稳定运行。文章对压水堆核电厂“死管段效应”产生严重腐蚀的成因进行分析,并对其腐蚀现象进行研究,针对其内部氧含量导致的严重腐蚀制订超声检测方案,确保“死管段”内不含氧,避免发生严重的设备腐蚀现象。

田湾核电站生产计划项目运行风险分析研究

通过对田湾核电站生产计划项目特点和运行风险进行分析,建立一套全面的风险管控框架,包括风险分级、风险缓解和监控等方面,并提出以工单为核心的“全过程”运行风险管控方法,将有助于提高核电厂生产计划项目运行风险管控的安全性和可靠性,降低潜在风险,促进核能的可持续发展。

华龙一号主管道电渣锭成分偏析控制

华龙一号核电主管道采用X2CrNiMo 18.12(控氮)超低碳奥氏体不锈钢制造,该钢种碳含量低,铬、镍含量高且范围窄,尤其是N含量控制难度大,对质量要求苛刻;同时主管道锭型达到百吨级,易产生成分偏析,通过对大型主管道电渣锭成分偏析的分析与研究,阐述了大型单相电渣锭成分均匀性的控制方法,并取得了良好的效果。

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。

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。