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.

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.

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.

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.

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

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

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.

Shanghai Power Station Auxiliary Equipment Works Forges Ahead

Shanghai Power Station Auxiliary Equipment Works (referred to as SDF) was established in April, 1980 on the base of the urban area previously owned by Shanghai Boiler Works so as to facilitate

抽水蓄能电站厂用电系统备自投设计及实现

大中型水电站厂用电系统接线复杂,备自投动作逻辑也不简单,同时还需考虑两级备自投之间的动作配合。针对某抽水蓄能电站10 kV及0.4 kV厂用电系统备自投的设计原则、动作逻辑等方面开展了研究,提出两级厂用电系统备自投间的定值及动作时间配合方案,可以保证电站厂用电系统的安全可靠运行。

Changes of Water Temperature and Harmful Algal Bloom in the Daya Bay in the Northern South China Sea

Economic development around the Daya Bay, China has profoundly affected the marine environment in the bay area in recent years, particularly since the operation of Daya Bay Nuclear Power Station （DNPS） in 1994. This study analyzed the changes of water temperature and harmful algal blooms （HABs） for two periods： 1983-1993 and 1994-2004, using in situ and satellite data. Results showed that yearly mean surface water temperature （SWT） and Chl-a concentration （Chl-a） increased by 1.1 ℃ and 1.9 mg/m^3, respectively, after 1994. The monthly occurrence of HAB was found to have increased also. HABs appeared only in spring and autumn before 1994, but occurred all the year round after 1994. SWT, Chl-a and HABs all increased significantly in May. Those changes were associated with environmental changes in this area, such as thermal discharge from the DNPS and enhancement of eutrophication from human activities around the Daya Bay.

汽轮机高位布置辅机冷却水系统优化

汽轮发电机组高位布置是燃煤发电机组的新型布置方案,与现有燃煤机组的空间结构存在较大的差异。为保障和提升高位布置辅机冷却水系统性能,按照功能与布置结构将辅机冷却水系统分为4个耦合的子系统,采用APROS软件建立了辅机冷却水系统模型,对高位布置辅机冷却水系统进行了优化设计,并将原系统与改进系统进行了定量对比和动态特性分析。结果表明:改进系统可降低辅机工作温度,节点温度峰值保持在65℃以下,冷却可靠性大幅提升。

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。

基于LabVIEW和Simulink的蒸汽发生器水位控制分布式仿真

蒸汽发生器作为压水堆的核心部件,研究不同工况下它的水位动态特性对核电站的安全评估和水位控制系统设计具有重要意义。提出了一种基于LabVIEW和Simulink的蒸汽发生器水位控制仿真方法。用Matlab/Simulink搭建蒸汽发生器水位控制系统仿真模型,用LabVIEW开发具有交互功能的水位控制人机界面,仿真模型与人机界面之间采用基于OPC中间件实现客户机\服务器模式的连接。仿真结果表明,本方法在保证计算精度的同时还具有人机交互性好、可扩展性强等特点,也可应用于核反应堆其他控制系统的分布式仿真。

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。

骨干调峰调频水电站厂用电系统立体防护策略研究

大型骨干调峰调频水电站通常地处偏远,环境较为恶劣,出现故障的概率高,防护难度大,严重影响发电机组和电网的安全稳定运行。水布垭电站通过探索提出了厂用电系统立体防护三大策略,即厂用电电源点选择及运行方式优化、不同电压等级下的分级防护与异常状态下厂用电故障的在线消除。经过多年实际运维检验,证明了防护策略的有效性,并提出了在制定和执行策略的过程中还应注意的事项,可供大中型调峰调频水电站厂用电安全运行维护管理参考。

水电站10 kV厂用电系统供电可靠性提升方法研究

以水布垭电厂为例,针对其10 kV厂用电系统供电可靠性提升方法进行了研究,从备自投闭锁控制逻辑优化和厂高变断路器控制优化两个方面提出了具体优化方案。一是增加了断路器保护跳闸闭锁备自投启动的保护控制逻辑,防止备自投合闸于故障母线导致事故扩大;二是对机组停机流程中分厂高变断路器顺序进行了优化,使发电机组在解列后能够继续通过厂高变断路器对厂用电系统进行供电。实际应用表明了有效性,确保了在紧急情况下厂用电系统的供电可靠性,降低了发生大面积失电的风险。

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。