In this study,the severe accident progression analysis of generic Canadian deuterium uranium reactor 6 was preliminarily provided using an integrated severe accident analysis code.The selected accident sequences were ...In this study,the severe accident progression analysis of generic Canadian deuterium uranium reactor 6 was preliminarily provided using an integrated severe accident analysis code.The selected accident sequences were multiple steam generator tube rupture and large break loss-of-coolant accidents because these led to severe core damage with an assumed unavailability for several critical safety systems.The progressions of severe accident included a set of failed safety systems normally operated at full power,and initiative events led to primary heat transport system inventory blow-down or boil off.The core heat-up and melting,steam generator response,fuel channel and calandria vessel failure were analyzed.The results showed that the progression of a severe core damage accident induced by steam generator tube rupture or large break loss-of-coolant accidents in a CANDU reactor was slow due to heat sinks in the calandria vessel and vault.展开更多
The hydrogen deflagration is one of the major risk contributors to threaten the integrity of the containment in a nuclear power plant, and hydrogen control in the case of severe accidents is required by nuclear regula...The hydrogen deflagration is one of the major risk contributors to threaten the integrity of the containment in a nuclear power plant, and hydrogen control in the case of severe accidents is required by nuclear regulations. Based on the large dry containment model developed with the integral severe-accident analysis tool, a small-break loss-of-coolant-accident (LOCA) without HPI, LPI, AFW and containment sprays, leading to the core degradation and large hydrogen generation, is calculated. Hydrogen and steam distribution in containment compartments is investi- gated. The analysis results show that significant hydrogen deflagration risk exits in the reactor coolant pump (RCP) compartment and the cavity during the early period, if no actions are taken to mitigate the effects of hydrogen accu- mulation.展开更多
The traumatic break of the ascending aorta is rare. We bring report the case of a 40-year-old man, a victim of accident of the public highway having caused a break of the posterior face of the ascending aorta. The exp...The traumatic break of the ascending aorta is rare. We bring report the case of a 40-year-old man, a victim of accident of the public highway having caused a break of the posterior face of the ascending aorta. The explorations scanno graphique and per operating highlighted this break. The treatment consisted of an edge-to-edge direct suture of the ascending aorta.展开更多
皮带运输机在煤矿生产中一直承担着煤炭运输的重要任务,其安全稳定运行是保障煤矿安全生产的前提。但是,皮带运输机在实际使用过程中会发生各种各样的故障,严重时会造成皮带断裂进而导致设备停转,给煤矿生产带来很大损失。因此,对发生...皮带运输机在煤矿生产中一直承担着煤炭运输的重要任务,其安全稳定运行是保障煤矿安全生产的前提。但是,皮带运输机在实际使用过程中会发生各种各样的故障,严重时会造成皮带断裂进而导致设备停转,给煤矿生产带来很大损失。因此,对发生断带事故的原因进行分析,探讨断带保护技术应用及安防装置设计。根据分析结论和实际情况,设计了皮带运输机断带安防装置,提出了一种基于ARM的PLC+DCS+GSM (Programmable Logic Controller+Distributed Control System+Global System for Mobile Communications,可编程逻辑控制器+分散控制系统+全球移动通信系统)综合安防系统设计方案,并对该系统进行了可行性分析。展开更多
为了评估安全壳完整时发生一回路破口事故后,放射性核素在封闭空间中扩散时的个人受照剂量,对放射性核素扩散迁移过程开展模拟计算。采用隔室模型对密闭空间进行物理建模,使用多参数一阶动力学微分方程描述放射性核素在密闭空间内的迁...为了评估安全壳完整时发生一回路破口事故后,放射性核素在封闭空间中扩散时的个人受照剂量,对放射性核素扩散迁移过程开展模拟计算。采用隔室模型对密闭空间进行物理建模,使用多参数一阶动力学微分方程描述放射性核素在密闭空间内的迁移过程,自主开发了放射性核素扩散计算程序DMRC(Diffusion and Migration of Radi-onuclide Code)。采用DMRC程序计算了TACT(Transport of ACTivity)基准题中的放射性核素活度和假想个人剂量,计算结果与基准解结果符合良好。最后,对某真实核电厂一回路破口事故进行模拟,计算了事故发生后30天内安全壳和外部环境的放射性活度以及假想个人剂量。结果显示:该事故发生后公众接受的最大有效剂量及最大甲状腺当量剂量均小于国家规定限值。结果表明:本文工作可以用于事故工况下的环境安全分析和人员健康评估。展开更多
文摘In this study,the severe accident progression analysis of generic Canadian deuterium uranium reactor 6 was preliminarily provided using an integrated severe accident analysis code.The selected accident sequences were multiple steam generator tube rupture and large break loss-of-coolant accidents because these led to severe core damage with an assumed unavailability for several critical safety systems.The progressions of severe accident included a set of failed safety systems normally operated at full power,and initiative events led to primary heat transport system inventory blow-down or boil off.The core heat-up and melting,steam generator response,fuel channel and calandria vessel failure were analyzed.The results showed that the progression of a severe core damage accident induced by steam generator tube rupture or large break loss-of-coolant accidents in a CANDU reactor was slow due to heat sinks in the calandria vessel and vault.
文摘The hydrogen deflagration is one of the major risk contributors to threaten the integrity of the containment in a nuclear power plant, and hydrogen control in the case of severe accidents is required by nuclear regulations. Based on the large dry containment model developed with the integral severe-accident analysis tool, a small-break loss-of-coolant-accident (LOCA) without HPI, LPI, AFW and containment sprays, leading to the core degradation and large hydrogen generation, is calculated. Hydrogen and steam distribution in containment compartments is investi- gated. The analysis results show that significant hydrogen deflagration risk exits in the reactor coolant pump (RCP) compartment and the cavity during the early period, if no actions are taken to mitigate the effects of hydrogen accu- mulation.
文摘The traumatic break of the ascending aorta is rare. We bring report the case of a 40-year-old man, a victim of accident of the public highway having caused a break of the posterior face of the ascending aorta. The explorations scanno graphique and per operating highlighted this break. The treatment consisted of an edge-to-edge direct suture of the ascending aorta.
文摘皮带运输机在煤矿生产中一直承担着煤炭运输的重要任务,其安全稳定运行是保障煤矿安全生产的前提。但是,皮带运输机在实际使用过程中会发生各种各样的故障,严重时会造成皮带断裂进而导致设备停转,给煤矿生产带来很大损失。因此,对发生断带事故的原因进行分析,探讨断带保护技术应用及安防装置设计。根据分析结论和实际情况,设计了皮带运输机断带安防装置,提出了一种基于ARM的PLC+DCS+GSM (Programmable Logic Controller+Distributed Control System+Global System for Mobile Communications,可编程逻辑控制器+分散控制系统+全球移动通信系统)综合安防系统设计方案,并对该系统进行了可行性分析。
文摘为了评估安全壳完整时发生一回路破口事故后,放射性核素在封闭空间中扩散时的个人受照剂量,对放射性核素扩散迁移过程开展模拟计算。采用隔室模型对密闭空间进行物理建模,使用多参数一阶动力学微分方程描述放射性核素在密闭空间内的迁移过程,自主开发了放射性核素扩散计算程序DMRC(Diffusion and Migration of Radi-onuclide Code)。采用DMRC程序计算了TACT(Transport of ACTivity)基准题中的放射性核素活度和假想个人剂量,计算结果与基准解结果符合良好。最后,对某真实核电厂一回路破口事故进行模拟,计算了事故发生后30天内安全壳和外部环境的放射性活度以及假想个人剂量。结果显示:该事故发生后公众接受的最大有效剂量及最大甲状腺当量剂量均小于国家规定限值。结果表明:本文工作可以用于事故工况下的环境安全分析和人员健康评估。
