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.

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

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。

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。

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。

田湾核电站配置风险管理体系

本文介绍了田湾核电站1-4号机组配置风险管理的适用范围、程序体系、组织机构和职责,说明了田湾核电站瞬时风险和累积风险阈值的设置方法以及阈值修订的管理流程,进入和退出风险管理矩阵的条件以及风险管理矩阵修订的管理流程,详细阐述了配置风险管理的实施方案,包括运行和维修配置风险管理流程、风险管理措施的制订和实施等。

海南昌江核电站温排水海域浮游植物群落特征

为探究海南昌江核电站周边海域浮游植物群落特征,于2022年4个季度在海南昌江核电站周边海域布设14个调查站位,对采集的浮游植物样品进行分类鉴定,并对其群落结构、种类组成、优势种类、生态指数等进行分析统计。结果表明:(1)调查海域全年度共监测到浮游植物4门37属118种(含变形和变种),种类组成以硅藻门占绝对优势,随后依次是甲藻门、蓝藻门和金藻门;(2)浮游植物生态类型以广温广布种和暖温暖水种为主,种类组成没有明显的季节性变化;(3)春季细胞丰度明显高于其余三季,达到31.26×10^(6) cells·m^(-3);(4)各季节浮游植物优势种类均为硅藻,主要包括角毛藻属、辐杆藻属、根管藻属和海莲藻属等属种,其中劳氏角毛藻和拟旋链角毛藻为全年度优势种类;(5)浮游植物的多样性指数(H′)范围为2.68~4.76,物种丰富度指数(D)范围为0.89~2.18,物种均匀度指数(J)范围为0.53~0.94,表明浮游植物生态群落种类丰富,群落结构复杂稳定。

核电站新增10 kV用电负荷电气系统设计

核电站厂用电系统连续可靠供电是核电站安全稳定运行的重要保障。在核电站6.6kV中压系统增加较大容量10k V用电负荷的情况较为少见。如何对新增10k V用电负荷后的电气系统进行设备选型以及安全校验是需要解决的问题。以核电站新增用电负荷为例,介绍其电气系统设计方法,为后续类似项目提供解决方案。

深海能源基站技术现状与发展趋势

深海能源基站是提高UUV续航力、扩大UUV工作范围的有效手段,将改变未来海战中UUV执行任务方式和作战规则。本文阐述深海能源基站的应用需求和工作特点,分析深海能源基站不同储能技术,重点介绍了国内外在燃料电池和核动力深海能源基站方面研究现状。从储能、部署难易、维护周期和使用方式4个方面,探讨了深海能源基站的未来发展趋势。研究表明,深海能源基站将围绕高能量密度和高功率、小型轻量模块化、长周期隐蔽免维护运行、能量信息非接触式高速同传4个方向发展。

基于不同计算方法的核电站起重机抗震分析研究

文中研究内容紧贴工程实际需求,针对目前国内外对核电起重机抗震分析采用的等效静力法、反应谱分析、考虑缺失质量模态残余刚性响应的反应谱分析、时程分析等不同分析方法,结合各类核电起重机产品研发项目进行深入研究;确定各种抗震计算方法的特点及适用条件,针对不同核电厂家提出的各种技术要求及计算条件,快速选择适宜的抗震计算方法进行分析,缩短研发周期,降低目标成本,满足新一代核电设备开发要求,适应客户及市场需求。

田湾核电站西边坡抗震稳定性研究

田湾核电站西边坡为核安全相关边坡,在进行边坡的稳定性评价时,地震作用应根据核电厂的极限安全地震动(万年一遇)确定,且边坡稳定性系数需满足核电厂抗震设计规范要求。在深入研究核电站西边坡工程地质条件的基础上,考虑多种计算工况,采用极限平衡法和有限差分法对边坡的稳定性进行了综合评价。计算结果表明,原田湾核电站西边坡整体是稳定的,但在罕见强震作用下存在局部滑移的风险;经削方治理后的田湾核电站西边坡无论处于天然状态还是罕见强震工况下,边坡都是稳定的,不会对核安全相关建筑构成威胁。

无定向闭合导线测量技术在核电中的应用

厂区负挖爆破、厂房±0.000 m以上结构、道路管网等施工,直接影响厂区测量控制点点位之间不通视、变形、破坏,甚至影响核电施工测量与质量。为了高效、高精度恢复厂区测量控制网,经过探讨、实践,利用无定向闭合导线测量技术进行核电厂区测量控制网点恢复,取得了良好的技术与经济效果。给核电施工期间的微型控制网复测、次级控制网点恢复或新增,以及其他项目通视条件较差、点位数量少、位置分散等影响因素的控制网施工测量提供良好的借鉴。