共查询到19条相似文献,搜索用时 194 毫秒
1.
冷态超压是指核电厂冷停堆期间一回路系统水密实状态下如果发生能量或质量注入,会造成一回路系统压力升高,为保证压力容器的完整性,RHR系统设置了3组安全阀,在压力超过其整定值时开启阀门。同时事故规程要求操纵员采取措施降低一回路系统的压力,稳定正常冷停堆状态。未预期温度变化是指RCS和RHR连接后,RHR系统及其支持系统(WCC系统、WES系统)的故障可能会造成一回路温度的异常变化。当温度变化率超过规定限值时,要求操纵员采取措施稳定一回路的温度。使用RELAP软件建立了停堆模型,对冷态超压事故及未预期温度变化事故后操纵员的主要操作进行了研究计算,提出了这两类事故后的操作指导,并提出了一个停堆工况下推荐运行范围。 相似文献
2.
针对船用核动力装置的特点,建立了船用堆一、二回路及控制系统的RELAP5模型,用RELAP5/MOD3.2程序对典型船用堆经济巡航工况下发生全部电源丧失事故进行模拟,分析了4种耗汽工况对事故进程的缓解效果。分析表明:事故后合理的耗汽运行方案能明显延缓事故进程,延缓时间为小时级别;耗汽量越小,二回路设备运行时间越长,二回路热阱持续时间也越长,一回路事故进程越缓慢。但太小的耗汽量会引起事故过程中蒸汽发生器(SG)二次侧水位过高甚至满水,进而威胁二回路设备的正常运行。同时,二回路设备数量众多,不同设备的最低运行汽量也不尽相同,应选择最有用和最低耗汽量的设备耗汽运行。本研究能对实际船用堆事故下的应急处理提供参考。 相似文献
3.
4.
5.
6.
7.
二级概率安全分析(PSA)可用来定量评估严重事故风险,是评价严重事故管理的良好工具。通过研究二级PSA应用于严重事故管理的一般方法与流程,以某二代改进型核电厂二级PSA模型为例,对严重事故管理导则中“一回路卸压”和“一回路应急注水”两个关键操作进行了定量评价。评价表明进入严重事故管理导则后立即执行“一回路卸压操作”可大幅度降低大量放射性释放风险,执行“一回路应急注水操作”对于降低进程较慢的事故序列大量放射性释放风险贡献较大。研究表明国内核电厂针对严重事故的管理还有进一步提升空间。 相似文献
8.
9.
《中国原子能科学研究院年报》2019,(0)
<正>在正常运行工况下,计算了堆芯放射性积存量、反射层组件放射性、钢屏蔽组件放射性、一回路源项、覆盖气腔源项、二回路源项、废气源项、废液源项和废固源项。计算结果表明,在正常运行工况下,气态和液态排放源项及公众最大个人有效剂量均满足相应国家标准要求。在事故工况下,分析了反应堆堆本体覆盖气体 相似文献
10.
11.
浮动式核电站长期在海洋环境中运行,各系统都会受到海洋运动条件的影响。非能动余热排出系统(PRHRS)可在核电站发生全厂断电事故的情况下带出堆芯衰变余热,防止堆芯熔化,是重要的反应堆辅助系统。本文以一种采用海水作为最终热阱的浮动式核电站作为研究对象,分别设计了一回路和二回路PRHRS,开展了静止和摇摆条件下反应堆系统发生全厂断电事故的计算,对两种PRHRS在静止和摇摆条件下的运行特性进行了分析。研究表明,静止条件二回路PRHRS具有更强的带热能力,摇摆条件下一回路PRHRS的带热能力更加稳定。 相似文献
12.
Level 2 Probabilistic Safety Analysis (PSA) can be used to quantitatively assess the risk of severe accident and is a good tool to evaluate the severe accident management. By studying the general method and procedure for the application of level 2 PSA in severe accident management, taking an improved generation-Ⅱnuclear power plant as an example, the “primary loop depressurization operation ” and the “ primary loop emergency water injection” in severe accident management guideline are quantitatively evaluated. Analysis shows that performing the “primary loop depressurization operation” immediately after entering the severe accident management guideline can greatly reduce the risk of large radioactive release, and performing “primary loop emergency water injection operation” contributes greatly to reducing the risk of large radioactive release in the slower accident sequence. The study shows that there still has further improvement room in severe accidents management for nuclear power plants in China. 相似文献
13.
T. Kukkola 《Nuclear Engineering and Design》1976,37(3):407-412
In the WWER-440 reactor the primary piping consists of six horizontal loops going rapidally from the pressure vessel, each loop having a horizontal steam generator. In this reactor type the relatively long primary piping with many curved sections requires special attention in order to successfully eliminate the consequences of the design basis accident. Emergency supports are located in appropriate places to restrict the movements of the pipe. Under normal conditions there is a gap of some centimeters between the pipe and a support so that in the pipe can be deformed freely under changing loads. This paper deals with those energy-absorbing structures used at the Loviisa Nuclear Power Plant for protection against impact loading. Places and circumstances where energy-absorbing structures are employed are specified. Development and design of impact absorber elements are discussed and impact tests are described. 相似文献
14.
15.
为研究海洋条件对海上浮动堆全厂断电事故后的事故进程及非能动安全系统运行特性的影响,通过建立海洋条件加速度场模型,基于RELAP5程序开发获得了适用于海上浮动堆的系统分析程序,并对程序进行了实验验证。利用所开发的程序通过建立双环路海上浮动堆及二次侧非能动余热排出系统的计算模型,开展了不同摇摆运动参数下海上浮动堆全厂断电事故的计算分析。计算结果表明,船体的横摇运动可加快全厂断电事故后浮动堆系统压力和温度的下降速度,堆芯余热能够被二次侧非能动余热排出系统有效导出;但横摇运动会造成事故后堆芯自然循环流量的显著降低,引起一回路系统和非能动余热排出系统中自然循环流量的大幅度振荡及周期性倒流。本文计算结果可为海上浮动堆非能动安全系统的设计提供参考。 相似文献
16.
In the designs of the new-generation reactor facilities, including floating nuclear heat and electricity plants, new passive
containment safety systems are used to increase operational safety. The objective of the present work is to validate experimentally
the effectiveness of heat removal by a system which lowers damaging pressure levels in the protective shell under conditions
of the maximum anticipated accident with loss of coolant in the first loop. The results of the experimental studies on a full-scale
model of a secondary loop of the first cooling loop for lowering damaging pressure confirm the validity of the technical decisions
made; all prescribed design characteristics of the cooling loop are upheld. 相似文献
17.
The design philosophy and requirements of the HTR-10 reactor building and the primary loop confinement are introduced in this paper. Also introduced are the design, fabrication and the installation of the HTR-10 primary loop pressure boundary system. The primary loop confinement comprises the sealed cavities of the reinforced concrete structure. The main components and the connected gas systems of the primary loop pressure boundary system are contained in the confinement. Under normal operating condition, the inside pressure of the confinement is kept at negative pressure to ensure the sealing function of the confinement. There is a rupture disk of overpressure protection in the confinement wall. After a depressurization accident the pressure of the confinement increases and the rupture disk will break. The air of the confinement is discharged directly to the atmosphere through the accident discharge chimney which is connected to the rupture disk without filter. The main components of the primary loop pressure boundary system consist of the reactor pressure vessel, the steam generator pressure vessel and the hot gas duct vessel. All the above main components are installed in the reactor cavity and the steam generator cavity. They are all nuclear safety class 1 components, whose materials production, design, fabrication, and tests are carried out according to ASME Section III and relevant Chinese nuclear codes. 相似文献
18.
Finite element models of a loop of the coolant system of a PWR (primary side and parts of secondary side) have been developed. The structural response of the models relating to an accident management (AM) load case involving secondary side bleed and feed as well as the fictitious extreme case of a blocked steam generator movement were analyzed. 相似文献
19.
针对钠冷快堆二回路系统的具体结构和运行特点,对中间热交换器、直流蒸汽发生器、钠缓冲罐以及泵、管道等设备和部件建立模型,采用FORTRAN语言自主编制了二回路系统热工水力瞬态分析程序SELTAC。利用中国实验快堆的停堆试验数据对所编制程序进行了初步验证。结果表明,程序计算值与试验值趋势一致,最大相对偏差不超过4.34%,吻合程度较好。将验证后的程序与一回路系统程序耦合,分析了某600 MW钠冷快堆在主热传输系统保持排热能力时的紧急停堆工况,得到了二回路系统的瞬态特性,为大型商用快堆电站的设计提供了参考。 相似文献