我国放射事故概况与原因分析

本文概述了新中国成立以来发生的放射事故概况，事故分类、分级，比较详细地分析了事故原因，指出我国放射事故发生率近十年虽然有所下降，但仍然高达平均每年约30起之多。事故的性质主要是责任事故。分析造成事故的直接原因，其中主要是管理不善，占事故总数的47.3%；其次是领导失职，占事故总数的20.2%；有10.2%的事故属技术性的设备意外故障。     

某厂可能发生的辐射事故与应急措施

本文探讨了某厂可能发生的辐射事故，介绍了事故应急措施。分析结果表明，某厂发生的最大可信事故是六氟化铀泄漏事故；在发生最大可信事故的情况下，对周围环境和公众的影响是很低的。     

放射性物质运输事故分析及后果评价方法

主要介绍国内外近年来在放射性物质运输事故后果评价方法方面的研究成果，描述了铁路运输和公路运输的事故景象、放射性物质运输事故的严重程度和类别，列出了运输事故情况下不同照射途径的剂量计算方法，并介绍了事故可能引起的健康效应和经济影响。     

典型事故工况下压水堆核电厂内工作人员辐射风险分析方法研究

基于概率论和确定论分析方法建立了事故工况下场内工作人员辐射剂量控制的体系。针对典型三代压水堆核电厂，建立了事故工况下场内工作人员辐射风险分析的方法论，并采用典型事故进行验证。验证结果表明，对于选取的堆外放射性系统相关典型事故，建立的辐射风险控制体系和分析方法可很好地评估并控制事故工况下场内工作人员的辐射风险。该方法可进一步扩展至堆芯相关事故以及其他堆外放射性系统相关事故，从而提升压水堆核电厂辐射防护最优化水平。     

中国先进研究堆事故源项分析

研究建立了中国先进研究堆（CARR）在事故工况下放射性核素从燃料芯块向环境释放的数学模型。根据CARR初步事故分析结果，对可能导致放射性向外界释放的5种事故工况（小破口失水事故、换热器传热板破裂事故、重水回路管道破裂事故、燃料操作事故、冷却剂流道堵塞事故）以及假想的3盒组件燃料板熔化超设计基准事故进行了源项分析，分别给出了不同事故和释放途径下释放到环境的放射性核素的量，以防止事故情况下公众和环境遭受过量放射性损伤。     

737原地浸出采铀工业性试验基地事故放射性废物释放及对地下水环境的影响

本文介绍原地浸出采铀方法的工艺流程及特点，讨论了我国原地浸出采铀工业性试验基地运行期间可能发生的几种事故及事故工况下放射性废物向环境的释放机制。通过对各类事故的分析，得出本工程的最大可信事故为地震造成的蒸发池废水泄漏事故。利用核素在包气带和饱水带中的迁移模式计算了各核素的峰值浓度分布，估算了事故剂量。最后分析了本采铀方法的推广应用前景     

船用核动力SGTR事故安全分析

本文论述了船用核动力装置蒸汽发生器传热管断裂事故（SGTR）安全分析的重要性。并以陆奥号核动力商船为例，运用事件树分析技术，对SGTR事故进行了安全分析。得出了事故后可能导致堆芯熔化的事故序列，确定了堆芯熔化数学模型，并进行了定量化分析。最后根据对支配性事故序列和各题头事件重要度的分析，提出了降低SGTR事故导致堆芯熔化发生概率应采取的相应措施。     

秦山核电厂SGTR事故及其处置研究

用ＲＥＬＡＰＳ／ＭＯＤ２程序和ＭＡＲＣＨ３程序对秦山核电厂多种假想ＳＧＴＲ事故及其所致严重事故进行了计算，分析了主要事故序列的事故进程，估算了严重事故下的熔堆时序，探讨了一些有效的事故处置措施及其干预效果。     

环境风险评价的探讨

本文在概述了环境风险评价的意义和方法的基础上，针以地其中关于事故序列的选取，事故发生概率的确定，气象观测数据的统计抽样，后果的表述及非事故风险与事故风险的叠加展开讨论，并提出了作者的见解。     

钠冷快堆的失流事故分析

钠冷快堆的失流事故分析王平，朱继洲（西安交通大学）关键词钠冷快堆，事故分析，失流１引言在钠冷快堆中，最典型的堆芯冷却系统故障或破坏事故是失流事故。作为设计基准事故之一，失流事故一旦发生，就要求事故保护停堆系统立即动作，实现事故保护停堆。但是，如果反应...     

Recent Development of Data Acquisition System on HL-2A

This paper introduced recent development of data acquisition system(DAS) on the HL-2A tokamak. The existing DAS has to be remodeled because of the evident improvement on HL-2A itself and the increasing amount of corresponding experimental data. First, the experimental network on HL-2A Tokamak as a communication center is described in detail. Secondly, "The File's Format & Criterion of Experimental Data on HL-2A Tokamak" as the core of the new software is also presented. Thirdly, not only a multi-screen image display system on HL-2A is discussed, but also the build-up of a new display wall system is dealt with. Finally, on the graphical WINDOWS platform and on the basis of the new Data File's Format & Criterion, the new software on HL-2A is described, including a new multi-layer database management program, a real-time processing program, a common interactive analytic processing program and a data post-processing program, which is now under development.     

反应堆保护系统可靠性指标的评价方法研究

反应堆保护系统的性能水平对核电厂安全、经济、可靠运行有很大影响。而实践中如何正确评价反应堆保护系统的可靠性指标,业界并未形成一致方法。本文选取简化的典型反应堆保护系统为研究对象,主要讨论拒动概率故障树分析和误动率马尔科夫方法的适用性,分析拒动概率、误动率两个指标分别适用的评价方法,并对示例系统的可靠性指标进行定量计算。本研究对进一步澄清国内反应堆保护系统可靠性评价中的方法问题,具有重要的参考价值。     

Combining disparate sources of information in the safety assessment of software-based systems

The main topic of the paper is a discussion on how to combine disparate sources of information in the safety assessment of software-based systems. This is based on experience gained through the licensing process of a programmable system in the Swedish nuclear power plant Ringhals, where a guideline for reviewing software in safety-related systems was applied. One lesson learned from this activity is that the approval of a programmable safety critical system, in particular one which is based on Commercial-Off-The-Shelf software, is based on a combination of disparate sources of information. This combination of information is made in a diagrammatic framework. An emerging methodology to combine information about disparate evidences in a systematic way is based on Bayesian Belief Networks. The objective is to show the link between basic information and the confidence one can have in a system.     

SHERNAN Computer Code for Simulating Burnup in a Three-Dimensional Reactor

The SHERHAN computer code was developed as an improved method of the heterogeneous theory, based on a new few-group formulation of the heterogeneous equations and the transformation of these equations from a matrix into a difference form and on the theory of heterogeneous parameters of reactor cells. The program simulates a temporal process during reloading of the reactor-core elements with movement of the control rods, giving rise to a critical state and smoothing the radial power distribution. The results contain data on the three-dimensional power distribution, burnup, isotope accumulation, and reactivity of the core elements. The typical simulation time for a 1500-channel reactor run is about 1 h on a 1000 MHz Pentium-4 PC.     

Influence of the Phase of the Antenna Current Standing Wave on the Power Flux in Ion Cyclotron Heating

For ion cyclotron resonance heating, the current on the antenna surface exists in a form of standing wave, and the phase of the poloidal current standing wave affects significantly on the performance of the coupling. In this paper, a coupling calculation is carried out based on a practical model for the loop antenna. The ion cyclotron wave coupling performance depends greatly on the antenna current propagation constant and the phase of standing wave. For a small antenna-current-propagation constant, the antenna coupling performance is more sensitive to a ?/2 change in the phase of standing wave.     

用自射线照相技术研究放射性核素在岩石和矿物上的吸附

应用自射线照相和岩相照相技术联合图象法研究了锕系元素和长寿命裂变产物在岩石和矿物上的吸附行为，直接观察到不同矿物和化学成份对核素的吸附。应用这个方法，研究了＾２３９Ｐｕ、＾２４１Ａｍ在花岗岩上的吸附，＾９０Ｔｃ在辉锑矿、锑赭石和脆硫锑铅矿上的吸附以及＾１２５Ｉ在灰硒汞矿上的吸附，得到了一些有价值的结果。     

核电厂中流固耦合现象数值模拟研究综述

流固耦合现象在核电厂中广泛存在，该现象引起的结构动力学问题对核电厂结构完整性和安全性有重要影响。目前，国内外对核电厂中流固耦合现象的研究给予越来越多的关注。本文介绍华北电力大学在该方面的一些研究进展，例如，快堆燃料组件抗震分析新的流体附加质量计算方法研究；蒸汽发生器换热管双管漩涡脱落的数值模拟；一个先进堆燃料组件平行板上流动引起的漩涡脱落数值模拟；由地震引起的自由表面对快堆主容器冲击现象的研究；移动粒子法求解液面晃动及晃动引起离散现象的研究等。     

A theoretical study of cyclon-effect in PWR downcomer during a LOCA blowdown

The current strategy based on the use of so-called cross-junction, allows partial modeling during blowdown episodes driven by larger-scale (flow features such as helical profile) in downcomers nuclear reactors. However a subtle but significant effect may appear by the combined action of two factors: on the one hand high azimuthal flow, on the other hand the intrinsic curvature of downcomer, and additionally in presence of a two-phases (vapor–liquid) a cyclon-effect can manifest. The present paper is a theoretical analysis of a possible cyclon-effect during blowdown episodes that allows a qualitative estimate of the impact on the calculations.