先进核电厂概率安全分析探讨

随着核电技术的不断发展与应用,概率安全分析技术已广泛应用于核电厂工程实践中.轻水堆核电厂的概率安全分析技术已发展得相当成熟,而先进核电厂的概率安全分析工作正在不断展开.本文试图对传统PSA技术应用于先进核电厂过程中可能遇到的问题进行探讨,首先从传统的轻水堆核电厂概率安全分析框架谈起,追溯其成因,然后基于先进核电厂的安全特性提出现有概率安全分析技术应用过程中遇到的问题,最后以高温气冷堆的概率安全分析为例提出先进核电厂概率安全分析的建议.     

Experimental Simulation on Transit Process of the 5MW Nuclear Heating Reactor

实验在５ＭＷ核供热堆全尺寸，全参数模拟回路ＨＲＴＬ－５上进行，指出供热堆从常温，常压条件向沸水运行工况的过渡要经过三个步骤：１）通过加不凝气体Ｎ２来增加初始压力，这一措施能有效地消除低压下的ｇｅｙｓｅｒｉｎｇ和闪蒸不稳定；２）在此压力下用小于极限功率密度的功率密度值０．１５ＭＷｍ－２加热反应堆至单相压水运行工况１．５ＭＰａ，此举可控制加热段出口温度低于产生汽泡的起始温度，进而避免了低干度密度波的发生；３）从压水向沸水工况的过渡。研究了三种从压水向沸水过渡方法，在此基础上提出用小功率，低欠热度向沸水过渡的方案，此方案可保证过渡过程中的流动稳定性。通过仔细地选择热工参数，可以得到５ＭＷ供热堆从冷态到沸水工况的稳定启动过程。此结果对研究两相流稳定性，对供热堆的设计和安全有重大意义。     

1，1′─［四甲基二硅撑］双（环戊二烯基三羰基钨配合物）的合成及反应

１，２－二环戊二烯基四甲基二硅烷与丁基锂作用生成［四甲基二硅撑］双（环戊二烯基负离子盐），后者随即与六羰基钨反应形成１，１－［四甲基二硅撑］双［环戊二烯基三羰基钨负离子盐］，（Ｍｅ２ＳｉＳｉＭｅ２）·［Ｃｐ′（ＣＯ）３Ｗ－］２·２Ｌｉ＋（Ｉ）．（Ｉ）分别与六种卤化物反应，生成在钨原子上引入取代基的产物：（Ｍｅ２ＳｉＳｉＭｅ２）．［Ｃｐ′Ｗ（ＣＯ）３Ｒ］２，（Ｒ：Ｍｅ，Ｃ２Ｈ５，２；ＰｈＣＨ２，３；ＣＨ２ＣＯＯＣ２Ｈ５，４；ＣＨ３ＣＯ，５；Ｐ３ｈＳｎ，６）．（Ｉ）用醋酸处理后，随即分别与ＣＣｌ４，ＮＢＳ及Ｉ２作用，生成相应的钨卤化物，（Ｍｅ２ＳｉＳｉＭｅ２）［Ｃｐ′Ｗ（ＣＯ）３Ｘ］２，（Ｘ：Ｃ１，８；Ｂｒ，９；Ｉ，１０），（Ｉ）与Ｆｅ３＋／Ｈ３Ｏ＋作用发生氧化偶联，生成双核Ｗ－Ｗ键产物（Ｍｅ２ＳｉＳｉＭｅ２）［Ｃｐ′Ｗ（ＣＯ）３］２，１１．（Ｃｐ′＝Ｃ５Ｈ４）     

在清华大学屏蔽试验堆上实现硼中子俘获治疗

硼中子俘获治疗（ＢＮＣＴ）是中子治癌研究中的一个重要课题。将清华大学屏蔽试验堆（９０１堆）的１＃孔道改建成ＢＮＣＴ的治疗孔道实现硼中子俘获治疗。为估价孔道改建的可行性，利用ＭｏｎｔｅＣａｒｌｏ程序进行了计算，并同实验和ＳＮ计算方法的结果进行了对比。其结论是功率为１ＭＷ的９０１反应堆１＃孔完全可以满足ＢＮＣＴ的要求，超热中子通量达１０９ｃｍ－２ｓ－１。     

200MW供热堆堆芯结构抗震试验模型设计的若干问题

为了保证 ２００ ＭＷ供热堆堆芯结构在地震时的完整性、控制棒通道在地震时畅通，和供热堆的抗震安全，有必要进行全尺寸的堆芯单元模型的抗震试验。从 ２００ ＭＷ供热堆堆芯结构的特点出发，研究了模型设计的原则和动力学相似的问题，重点对堆内支承，燃料组件和锆盒等重要部件的动力学简化原则进行了阐述，利用有限元法分析了堆芯结构的动力学特性，讨论了试验模型和计算模型的关系，以及支架的设计问题，为台架试验打下了基础。通过本研究，不仅可对供热堆设计方案的性能进行恰当的评价，而且可指出进一步改善设计使结构达到优化的方向，保证供热堆的安全运行。     

HTR-10 大破口事故下结构特性的瞬态分析

１０ＭＷ模块式高温气冷反应堆（ＨＴＲ－１０）的热气导管压力壳的双端断裂事故属假想极限事故。当热气导管断裂后,高压的一回路冷却剂气体（３ＭＰａ）通过破口向堆舱猛烈喷放,一回路迅速卸压,并形成强卸压冲击波。利用了改进后的Ｋ－ＦＩＸ（ＦＬＸ）程序,对该事故下冷却气体喷放过程中堆体内主要结构部件（压力壳左支承、堆芯壳支承、堆芯壳）的安全特性进行了瞬态分析。通过计算,给出了破口处的压力瞬变、流量瞬变和堆芯壳上下两端的压差瞬变,以及在卸压冲击波作用下堆芯壳的膜应力和弯曲应力。最后,利用计算分析定量地给出了大破口极限事故下ＨＴＲ－１０的堆体主要结构部件的安全系数。结果表明,即使在极限事故下,ＨＴＲ－１０堆体结构仍有良好的安全特性。     

深水池式低温供热堆的设计研究

介绍了深水池式供热堆（ＤＰＨＲ）的设计特点，给出了 １２０ ＭＷ供热堆的主要设计参数、投资估算和运行成本。并详细分析了 ＤＰＨＲ的优良安全性能，指出这是一种结构简单、造价低廉、具有固有安全性能的堆型。     

钨,钼羧酸合过氧配合物的合成及性质研究

引进能和钨酸钼形成稳定的五元环的羧酸类配体，制得了十种新的稳定的钨，钼羧酸赤氧配合物：（ＮＨ４）２「ＭＯ（Ｏ２）２（Ｃ２Ｏ４）」（Ｍ＝Ｗ或Ｍｏ）；（ＮＨ４）「ＭＯ９Ｏ２）２Ｌ」．２Ｈ２Ｏ和（ＮＨ４）４「Ｍ２Ｏ２（Ｏ２）４（Ｃ４Ｈ２Ｏ６）」．４Ｈ２Ｏ。测定了这些氧配合物固体的Ｒａｍａｎ和ＩＲ光谱以及水溶液的Ｒａｍａｎ光谱，并对配位结构进行了探讨，研究了这些过氧配合物的热稳定性。     

β-九钨锰杂多配合物异构体的合成及催化活性研究

报道了ＡβＭｘＨｙ［ＭＷ９Ｍｎ３（Ｈ２Ｏ）３Ｏ３７］·ｎＨ２Ｏ（Ｍ＝Ｓｉ，Ｇｅ，Ｇａ；Ｍ＝Ｂｕ４Ｎ＋，Ｋ＋）的合成方法并对ＩＲ、ＵＶ、磁化率以及催化活性等进行研究。     

核设施厂址选择的外部人为事件研究

在评价一个厂址是否适于建造核设施时,必须考虑下列外部人为事件的潜在危害：飞机坠毁、爆炸以及着火等。如果事件发生的概率等于或大于设计基准概率值,则应确定设计基准事件,保证核设施足够的安全。应用了保守和简单假设的确定论方法,分析评价了对１０ＭＷ高温气冷堆、２００ＭＷ核供热堆及２０ＭＷ军用研究堆等核设施可能有潜在影响的外部人为事件。评价结果表明：在筛选距离值范围内的外部人为事件的潜在源都不会危及厂址的安全,上述反应堆所选的推荐厂址都是适宜的。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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