共查询到17条相似文献,搜索用时 125 毫秒
1.
采用Risk Spectrum 1.3版软件建立事件树模型,对小LOCA始发事件下的堆芯损伤事故序列进行校核计算研究,分析得出了地坑滤网堵塞对于我国大型先进压水堆安全的影响。结果表明,虽然我国大型先进压水堆对于地坑滤网在设计上进行了优化改进,但在小LOCA始发事件下发生地坑滤网堵塞对于电站安全的影响仍然很高,地坑滤网堵塞问题仍然不能忽视。 相似文献
2.
3.
4.
5.
6.
7.
8.
《核科学与工程》2010,(Z1)
安全壳地坑滤网承担了重要的安全功能,其性能直接决定了应急堆芯冷却系统(ECCS)的可靠性和核电站的安全性。在早期设计中,假设安全壳地坑滤网堵塞率小于50%,这一假设不是保守的,存在现实的重大核安全风险,应该予以改进。地坑滤网上游分析用于确定地坑滤网设计条件,是地坑滤网改进的关键步骤。本文介绍了CPR1000安全壳地坑滤网上游分析的相关技术过程、研究经验及主要技术结论。通过精细分析方法在碎片产生及碎片传输分析环节中的应用,有效地减少了地坑滤网碎片负载估算量,避免了因过度保守引起的设备设计和布置困难。上游分析成果不仅用于岭澳二期地坑滤网改进项目,还可为优化后续CPR1000地坑滤网设计方案提供指导。 相似文献
9.
10.
11.
12.
为建立基于现场可编程门阵列(FPGA)的反应堆保护系统的可靠性模型,以对系统安全提供有效的分析与验证手段。本研究采用故障树、随机Petri网模型,对CANDU堆1号停堆系统(SDS1)单通道进行可靠性建模与分析。对故障树模型分析得到最小割集,以顶事件发生概率作为系统故障概率,在考虑故障检测、维修与定期试验情况下对随机Petri网模型进行仿真得到系统的拒动概率。研究结果表明,故障树和状态空间方法存在一定局限性,随机Petri网能够反映故障检测与定期试验对反应堆保护系统的影响,可以动态地反映系统可靠性,并且避免了状态空间爆炸问题。因此,本研究建立的随机Petri网模型适用于反应堆保护系统的可靠性建模。 相似文献
13.
在分析M310堆型核电站辐射屏蔽设计中由于工具限制存在的问题以及“华龙一号”堆型核电站辐射屏蔽设计提出的要求的基础上,从程序界面、输入接口、计算功能和辐射场应用扩展4个方面提出先进压水堆核电站辐射屏蔽优化设计对于蒙特卡罗(MC)方法的要求。MC方法在“华龙一号”辐射屏蔽优化设计的应用实践表明,基于MC方法的计算程序在程序界面、输入接口和辐射场应用扩展方面进一步提升之后,可在先进压水堆核电站辐射屏蔽优化设计方面发挥巨大的作用,显著提升核电站辐射屏蔽优化设计的水平。 相似文献
14.
The present study conducts a critical review of relevant research that pertains to Generic Safety Issue 191 (GSI-191) and the chemistry and corrosion behavior of the various materials present in the containment sump of a pressurized water reactor (PWR). Thermodynamic simulations, integrated tests, and benchtop tests have determined the structure of the potential precipitates that may clog the sump strainer and cause a failure of the emergency core cooling system (ECCS). Based on this research, it was determined that the available research has been insufficient in terms of simulating the transient temperature behavior in the containment sump in the post loss-of-coolant environment. Research gaps are identified, and recommendations for future research are presented. 相似文献
15.
核电厂失水事故工况下,化学效应可能引起地坑过滤器过度堵塞,影响应急堆芯冷却系统或安全壳喷淋系统的再循环功能,导致堆芯、安全壳丧失冷却,威胁核电厂的安全。本文以秦山核电厂二期扩建工程为研究对象,开展失水事故工况下潜在化学产物对地坑过滤器压头损失的影响研究。结果表明,秦山核电厂二期扩建工程安全壳内含Al材料和保温材料在地坑环境中会析出Al、Si,Al、Si元素在地坑介质降温过程中形成了化学沉淀物,化学沉淀物会在地坑过滤器碎片床上沉积,堵塞碎片床流道,缩小碎片床孔隙率,导致地坑过滤器压头损失增加。因此,秦山核电厂二期扩建工程失水事故后存在化学效应,在地坑过滤器性能评估、下游效应分析中应予以考虑。 相似文献
16.
17.
Jeong-Ik Lee Jin Yong Lee Soon Joon Hong Ju Yeop Park Yong-Ho Ryu Manwoong Kim 《Annals of Nuclear Energy》2011,38(2-3):681-693
After TMI-2 accident, long-term core cooling management takes more importance rather than short-term management since probabilistic safety assessment performed revealed that long-term management had higher risk than the risk from short-term management. Regarding to this, since 1992, blockage of sump suction strainer was taken a place in Barseback Unit 2 (Sweden, BWR) and the United States Nuclear Regulatory Commission (USNRC) took into consideration as a General Safety Issue 191 (GSI-191), “PWR Sump Blockage,” in 1998 and opening an investigation.As a response to GSI-191 the Nuclear Energy Institute (NEI) submitted a recirculation sump evaluation methodology called NEI 04–07. In this methodology 0.75 was recommended for blow-down transport to lower containment based on the study on a boiling water reactor sump clogging issue and engineering judgment. USNRC quantitatively evaluated the blow-down transport in the safety evaluation report to NEI 04–07, and concluded the recommended blow-down transport fraction in NEI 04–07 was sufficiently conservative. However, the safety evaluation report to NEI 04–07 includes many values in evaluation steps which depend much on the containment configuration and engineering judgment. In particular the dependency on the plant type limits the generality of the USNRC’s conclusion on blow-down transport, when the considered plant is different from the volunteer plant.This study provides a modified evaluation method and results of debris blow-down transport for an Optimized Power Reactor 1000 MWe (OPR1000) in Korea. The modified method includes more realistic physical background with less uncertainty while providing consistent result with NEI and USNRC methods. 相似文献