共查询到18条相似文献,搜索用时 109 毫秒
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EPR与CPR1000严重事故缓解措施比较 总被引:1,自引:0,他引:1
简述了EPR的严重事故缓解措施,包括严重事故专用卸压阀,安全壳内换料水箱(IRWST),可燃气体控制系统,堆芯熔融物捕集、稳定和冷却系统,严重事故下安全壳内热量导出系统,双层安全壳,严重事故专用仪表和控制系统,严重事故下不间断供电系统,严重事故运行策略等,并与CPR1000严重事故缓解措施比较,提出CPR1000严重事故缓解措施改进方向。 相似文献
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介绍了堆芯损伤评价的指导方法,并将西屋公司的CDAG方法论应用于EPR机组进行严重事故堆芯损伤研究。CDAG堆芯损伤程度的评价主要由2个参数判断:安全壳辐射监测值(CRM)和堆芯出口热电偶读数(CET)。本文讨论了CRM与CET的堆芯损伤估算结果存在差异的原因,分析结果表明:①CDAG是一种适用于EPR机组严重事故下堆芯损伤评价的方法;②CDAG方法能反映实时的堆内裂变产物释放的份额,能够快速地为应急组织决策提供支持;③基于EPR设计的CRM和CET整定值的保守计算结果显示出一个较为合理的趋势和范围;④释放方式、燃耗、RCS裂变产物滞留等因素对堆芯损伤估算结果有较大的影响。 相似文献
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PWR堆芯不同状况下安全壳内辐射水平的计算 总被引:2,自引:0,他引:2
介绍一个用于计算压水堆在正常冷却剂释放、间隙释放和堆芯溶化时安全壳内辐射监测仪表读数值的计算机程序CCRLCC。利用国际原子能机构技术文件中给出的参数输入该程序计算得到的结果和该文件中所给数据进行了比较,从而验证了程序的正确性。应用CCRLCC可以计算在停堆24 h内任意时刻不同堆芯损伤状况下的安全壳辐射监测仪表读数。该程序可以应用于基于安全壳内辐射水平提高的应急行动水平的制定,为事故期间根据安全壳内辐射监测仪表读数确定堆芯损伤状况提供依据。 相似文献
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为了确保有效的缓解严重事故,需要对用于缓解和监测严重事故进程的重要设备、仪表在严重事故环境下的可用性进行评估.而温度、压力、湿度、辐射等参数是可用性评估的重要输入条件.本文针对百万千瓦级压水堆核电机组,参考美国核管会发布的《轻水堆核电厂事故源项》(NUREG-1465)关于严重事故后放射性物质的释放阶段和释放份额的假设,计算出事故后由堆芯释放到安全壳内的放射性源项.对于放射性物质在安全壳内的分布,不考虑喷淋和泄漏的影响,计算并分析了严重事故后安全壳内的γ和β辐射环境条件,并与APl000的设备鉴定源项进行了对比分析.本文的计算对于设备和仪表在严重事故后的可用性分析以及其所需耐受的辐射条件具有重要的参考意义. 相似文献
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事故期间安全壳内的辐射水平是堆芯损伤评价和进行防护决策的重要依据,计算不同堆芯状况下安全壳内辐射监测仪表示值是应用该方法的前提条件.文章比较了正常冷却剂释放、间隙释放和堆芯熔化状况下不同核素对安全壳内辐射监测仪表示值的相对贡献.在安全壳内无喷淋情况下,安全壳内辐射监测仪表示值主要来自碘和惰性气体;安全壳内有喷淋情况下的辐射监测仪表示值主要来自于惰性气体. 相似文献
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压水堆核电厂发生严重事故期间,从主系统释放的蒸汽、氢气以及下封头失效后进入安全壳的堆芯熔融物均对安全壳的完整性构成威胁。以国内典型二代加压水堆为研究对象,采用MAAP程序进行安全壳响应分析。选取了两种典型的严重事故序列:热管段中破口叠加设备冷却水失效和再循环高压安注失效,堆芯因冷却不足升温熔化导致压力容器失效,熔融物与混凝土发生反应(MCCI),安全壳超压失效;冷管段大破口叠加再循环失效,安全壳内蒸汽不断聚集,发生超压失效。通过对两种事故工况的分析,证实了再循环高压安注、安全壳喷淋这两种缓解措施对保证安全壳完整性的重要作用。 相似文献
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采用MELCOR程序模拟非能动先进压水堆DVI管小破口始发严重事故下裂变产物释放行为。结果表明:当堆芯开始熔化后,Cs I从堆芯中释放到一回路系统,通过破口喷放到安全壳,惰性气体迅速释放到安全壳。安全壳失效前,安全壳内的Cs I和惰性气体份额最高分别约为70%、83%,环境中的Cs I和惰性气体份额为10-5数量级。安全壳失效后,安全壳内的Cs I和惰性气体份额分别降到了45%、0.38%,环境中的Cs I和惰性气体份额约为28%、90%。 相似文献
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For a nuclear fission system, we calculated Δkeff, which arise from system material composition changes, by two different approaches, the MCNP perturbation technique and the MCNP difference method. For every material composition change, we made four different runs, each run with different cycles or each cycle generating different neutrons, then we compared the two Δkeff that are obtained by two different approaches. As a material composition change in any particular cell of the nuclear fission system is small compared to the material compositions in the whole nuclear fission system, in other words, this composition change can be treated as a small perturbation, the Δkeff results obtained from the MCNP perturbation technique are much quicker, much more efficient and reliable than the results from the MCNP difference method.When a material composition change in any particular cell of the nuclear fission system is significant compared to the material compositions in the whole nuclear fission system, both the MCNP perturbation technique and the MCNP difference method can give satisfactory results. But for the run with the same cycles and each cycle generating the same neutrons, the results obtained from the MCNP perturbation technique are systemically less than the results obtained from the MCNP difference method. To further confirm our calculation results from the MCNP4C, we run the exact same MCNP4C input file in MCNP5, the calculation results from MCNP5 are the same as the calculation results from MCNP4C.We need caution when using the MCNP perturbation technique to calculate the Δkeff as the material composition change is large compared to the material compositions in the whole nuclear fission system, even though the material composition changes of any particular cell of the fission system still meet the criteria of MCNP perturbation technique. 相似文献
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Leonhard Meyer Giancarlo Albrecht Cataldo Caroli Ivan Ivanov 《Nuclear Engineering and Design》2009,239(10):2070-2084
The DISCO test facility at Forschungszentrum Karlsruhe (FZK) has been used to perform experiments to investigate direct containment heating (DCH) effects during a severe accident in European nuclear power plants, comprising the EPR, the French 1300 MWe plant P’4, the VVER-1000 and the German Konvoi plant. A high-temperature iron–alumina melt is ejected by steam into scaled models of the respective reactor cavities and the containment vessel. Both heat transfer from dispersed melt and combustion of hydrogen lead to containment pressurization. The main experimental findings are presented and critical parameters are identified.The consequences of DCH are limited in reactors with no direct pathway between the cavity and the containment dome (closed pit). The situation is more severe for reactors which do have a direct pathway between the cavity and the containment (open pit). The experiments showed that substantial fractions of corium may be dispersed into the containment in such cases, if the pressure in the reactor coolant system is elevated at the time of RPV failure. Primary system pressures of 1 or 2 MPa are sufficient to lead to full scale DCH effects. Combustion of the hydrogen produced by oxidation as well as the hydrogen initially present appears to be the crucial phenomenon for containment pressurization. 相似文献
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在广泛调研和分析现有几何建模方法特点的基础上研发了具有可视化用户界面的自动建模程序系统MCAM.它可以实现多种商用软件CAD模型与MCNP模型之间的相互转换,且提供了模型建立、预处理、属性分析等基本功能和计算结果可视化及基于医学映像建模接口等扩展功能.全面系统地介绍了MCAM的设计思想与原理、总体结构、主要功能和国际合作协议框架下的应用测试等情况.实践表明,它是一个实用的MCNP计算辅助工具和核设计与核分析质量保证工具. 相似文献
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Daniel Quniart 《Nuclear Engineering and Design》1993,144(2)
This document describes current thinking within the Institute for Protection and Nuclear Safety (IPSN) regarding developments desirable from the viewpoint of safety in a new generation of nuclear power plants, the construction of which could begin in France at the end of the nineties. Significant improvements must be sought, particularly as regards the containment, including the core meltdown case. The operating organization, Electricité de France (EDF), is now considering establishing the basis of a project of European dimension (European Pressurized water Reactor - EPR), in connection with German utilities and the Franco-German vendor Nuclear Power International (NPI); the first options important for safety are to be presented and discussed from September-1993. 相似文献
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对MCNP程序的二次开发 总被引:4,自引:1,他引:3
高彦锋 《核电子学与探测技术》1998,18(3):192-195,241
MCNP是一个超大型,先进的多功能蒙特卡罗中子-光子耦合便运程序,在世界范围内得到了广泛的应用,在国内,MCNP主要用于核保障技术,核临界,核聚变,变温汽冷堆,微堆,新堆等方面的计算,本文着重介绍几年来应用MCNP的开发经验和交互绘图功能的配制,总结了一些应用体会,最后探讨了国内所用MCNP的版本应用中表现出的一些不足。 相似文献