CU纳米线的高温原位加热XRD研究

采用电化学沉积方法,在孔径约50 nm的阳极氧化铝模板中生长Cu纳米线,经过高温原位加热XRD实验,证实了其热膨胀系数约2.6×10-5 K-1,稍大于块体Cu,与文献中Cu纳米线近似为零的热膨胀系数有明显的区别.对这一现象进行了简要的讨论后得出结论认为:基于模板生长的Cu纳米线,其晶格完整程度是决定热膨胀的重要因素.     

BEPCII电子日志系统

由于北京正负电子对撞机重大改造工程(BEPCII)建设和未来运行的要求,需要提供一个开放的电子日志平台,供BEPCII开发和运行人员进行日志录入并通过网页访问电子日志系统,摆脱传统的书面形式的日志,给大家提供一个公开透明的日志平台.本电子日志系统以德国DESY的电子日志系统为模板研制而成.用了目前比较成熟的JSP技术来生成动态Web应用.本文将介绍BEPCII电子日志系统的研发背景和过程.     

Theoretical research on the transport and ionization rate coefficients in glow discharge dusty plasma

The electron kinetic model for investigating the transport and ionization rate coefficients of argon glow discharge dusty plasma is developed from the Boltzmann equation.Both of the electron-neutral and electron-dust collisions are considered as collision terms in the kinetic equation.The kinetic equation is simplified by employing the local approximation and nonlocal approach under the same discharge conditions,and the corresponding simplified kinetic equations are known as local and nonlocal kinetic equations respectively.Then the electron energy distribution function(EEDF)is obtained by numerically solving the local and nonlocal kinetic equations and the dust charging equations simultaneously.Based on the obtained EEDFs,the effective electron temperature,electron mobility,electron diffusion coefficient and ionization rate coefficient are calculated for different discharge conditions.It is shown that the EEDFs calculated from the local kinetic model clearly differ from the nonlocal EEDFs and both the local and nonlocal EEDFs are also clearly different with Maxwellian distributions.The appearance of dust particles results in an obvious decrease of high energy electrons and increase of low energy electrons when axial electric field is low.With the increase of axial electric field,the influence of dust particles on the EEDFs becomes smaller.The electron mobility and diffusion coefficients calculated on the basis of local and nonlocal EEDFs do not differ greatly to the dust-free ones.While,when dust density nd=10^6 cm^?3,the electron mobility increases obviously compared with the dust-free results at low axial electric field and decreases with the increasing axial electric field until they are close to the dust-free ones.Meanwhile,electron diffusion coefficients for dusty case become smaller and decrease with the increasing axial electric field.The ionization rate coefficients decrease when dust particles are introduced and they approach the dust-free results gradually with the increasing axial electric field.     

“第一届中国(国际)核电仪控技术大会”征文通知

各有关单位:随着我国核电的快速发展,对满足核电需求的仪控技术与装置的研究、设计、制造、选型、应用、维护以及国产化水平都提出了越来越高的要求。为了更好地推动我国核电仪控技术的发展,促进产学研用的紧密结合,同时促进我国核电学术界的国际交流,中国核学会与中国仪器仪表学会共同研究决定联合举办第一届中国(国际)核电仪控技术大会。     

Analysis of the characteristics of the plasma of an RF driven ion source for a neutral beam injector

A radio frequency(RF)driven ion source is a very important component of a neutral beam injector for large magnetic confinement fusion devices.In order to study the key technology and physics of an RF driven ion source for a neutral beam injector in China,an RF ion source test facility was developed at the Institute of Plasma Physics,Chinese Academy of Sciences.In this paper,a two-dimensional fluid model is used to simulate the fundamental physical characteristics of RF plasma discharge.Simulation results show the relationship of the characteristics of plasma(such as electron density and electron temperature)and RF power and gas pressure.In order to verify the effectiveness of the model,the characteristics of the plasma are investigated using a Langmuir probe.In this paper,experimental and simulation results are presented,and the possible reasons for the discrepancies between them are given.This paper can help us understand the characteristics of RF plasma discharge,and give a basis for further R&D for an RF ion source.     

真丝绸的低压汞灯光引发接枝共聚研究

本工作用低压汞灯作为光源,以丙烯酸羟丙酯(2-Hydroxypropyl acrylate,HPA)为单体,对真丝绸的紫外光光化学接技改性进行了系统研究,反应体系中无任何引发剂或者光敏剂.用衰减全反射红外光谱(Attenuated total reflectance infrared spectroscopy,ATR-IR)、差示扫描量热法(Differential scanning calo-danetry,DSC)和热重分析(Thermal gravity analysis,TGA)等对光接枝产物进行了表征.探索了光照反应时间、单体浓度、pH值、多官能团单体的存在对接枝率的影响规律.研究表明,此方法可获得较高的接枝率,且低压汞灯具有无污染、设备简便价格低廉、寿命长,易于操作等优点,是一种有效的真丝绸改性方法.     

纪念王淦昌先生诞辰100周年

2007年5月28日,是我国杰出的核物理学家、中国核学会第一任理事长王淦昌先生诞辰100周年纪念日.中国核学会与相关单位一起举办了一系列活动,缅怀先辈,激励后人. 王淦昌先生是我国杰出的核物理学家、中国科学院资深院士、"两弹一星"功勋奖章获得者、中国实验原子核物理和宇宙射线及粒子物理研究的奠基人.     

Optimization of the Water-Cooled Structure for the Divertor Plates in EAST Based on an Orthogonal Theory

An orthogonal experimental scheme was designed for optimizing a water-cooled structure of the divertor plate.There were three influencing factors:the radius R of the watercooled pipe,and the pipe spacing L₁ and L₃.The influence rule of different factors on the cooling effect and thermal stress of the plate were studied,for which the influence rank was respectively R>L₁>L₃ and L₃>R>L₁.The highest temperature value decreased when R and L₁increased,and the maximum thermal stress value dropped when R,L₁ and L₃ increased.The final optimized results can be summarized as:R equals 6 mm or 7 mm,L₁ equals 19 mm,and L₃ equals 20 mm.Compared with the initial design,the highest temperature value had a small decline,and the maximum thermal stress value dropped by 19%to 24%.So it was not ideal to improve the cooling effect by optimizing the geometry sizes of the water-cooled structure,even worse than increasing the flow speed,but it was very effective for dropping the maximum thermal stress value.The orthogonal experimental method reduces the number of experiments by 80%,and thus it is feasible and effective to optimize the water-cooled structure of the divertor plate with the orthogonal theory.     

Recent Progress of the HL-2A Multi-Channel HCOOH Laser Interferometer/Polarimeter

A multichannel methanoic acid（HCOOH,λ= 432.5μm） laser interferometer/polarimeter is being developed from the previous eight-channel hydrogen cyanide（HCN,λ=337 μm） laser interferometer in the HL-2A tokamak.A conventional Michelson-type interometer is used for the electron density measurement,and a Dodel-Kunz-type polarimeter is used for the Faraday rotation effect measurement,respectively.Each HCOOH laser can produce a linearly polarized radiation at a power lever of ³0 mW,and a power stability <10%in 50 min.A beam waist（diameter d₀≈12.0 mm,about 200 mm away from the outlet） is finally determined through a chopping modulation technique.The latest optical layout of the interferometer/polarimeter has been finished,and the hardware data processing system based on the fast Fourier transform phasecomparator technique is being explored.In order to demonstrate the feasibility of the diagnostic scheme,two associated bench simulation experiments were carried out in the laboratory,in which the plasma was simulated by a piece of polytetrafluoroethene plate,and the Faraday rotation effect was simulated by a rotating half-wave plate.Simulation results agreed well with the initial experimental conditions.At present,the HCOOH laser interferometer/polarimeter system is being assembled on HL-2A,and is planned to be applied in the 2014-2015 experimental campaign.     

Instructions for Manuscript Preparation

<正>Plasma Science and Technology(PST)is a journal reporting novel experimental and theoretical results and progress of interdisciplinary and application sciences in the fields related to Plasma Physics.Specific interested areas include:basic plasma phenomena;magnetically confined plasma;inertially confined plasma;astrophysics and space plasma;low temperature plasma;plasma     

AP1000核电厂丧失正常给水稳压器防满水措施研究

在某AP1000核电厂丧失正常给水事件中，由于一系列的误操作导致稳压器满水，而稳压器安全阀在多次打开后可能无法重新关闭，不满足核电厂Ⅱ类工况验收准则。文章分析了该事件中稳压器满水的原因，即在非能动余热排出热交换器（PRHR HX）冷却能力充足的情况下，系统不适当的降压导致环路中冷却剂闪蒸，进而导致稳压器满水，此时通过开启堆顶放气阀启动应急下泄的方式无法有效降低稳压器液位。最后给出了AP1000核电厂丧失正常给水事故中防止稳压器满水的建议措施，即在RCS降压过程中，应确保RCS压力始终高于热管段温度对应的饱和压力，进而确保冷却剂不发生闪蒸。      

AP1000核电厂应对全厂断电事故的稳压器防满溢对策研究

AP1000核电厂若在全厂断电事故下丧失正常给水,会引起稳压器满溢,将通过稳压器安全阀排放液体冷却剂,引起反应堆冷却剂水装量流失,增大反应堆堆芯裸露的风险。与此同时,安全壳内的放射性水平因稳压器满溢可能会增大,增大向环境排放大量放射物质的可能。为防止稳压器满溢,本工作进行了解决或缓解稳压器满溢的对策研究。结果表明,增大非能动余热排出系统（PRHRS）热交换器的传热面积,可防止稳压器满溢;合理降低安全壳内置换料水箱（IRWST）的背压,可增大达到稳压器满溢的裕度,有效地缓解稳压器满溢;增大稳压器的自由容积,可防止稳压器满溢。此结论对AP1000核电厂的设计和事故分析有一定的参考作用。     

全厂断电事故下AP1000非能动余热排出系统分析

利用RELAP5/MOD3.3程序对AP1000反应堆一回路及非能动系统进行建模计算,给出了AP1000非能动余热排出系统（PRHRS）在全厂断电事故下的瞬态响应特性。计算结果表明：情况1,PHRH系统由蒸汽发生器低水位与低启动给水流量符合信号启动,稳压器安全阀的开启导致PRHRS发生倒流现象,并会引起堆芯冷却剂过热沸腾、压力容器进出口温差过大等后果;情况2,由断电信号直接触发PRHRS,触发前安全阀不开启,此时PRHRS正常运行。     

压水堆一回路卸压措施影响因素研究

研究压水堆一回路管道小小破口失水事故叠加辅助给水失效导致的高压堆芯熔化严重事故进程，对比验证不同严重事故缓解措施入口温度条件下一回路卸压缓解途径的充分性和有效性，并确认较佳的一回路冷却系统（RCS）降压途径。结果显示，以低于650℃的温度作为降压缓解措施入口条件，可及时恢复可能的堆芯冷却能力。一、二回路卸压效果分析表明，考虑了长期衰变热移出注水流量和堆芯过冷度要求，较佳的卸压配置为初期打开一列稳压器卸压阀，同时迅速恢复辅助给水并开启蒸汽发生器卸压阀。      

Detailed evaluation of coolant injection into the reactor vessel with RCS depressurization for high pressure sequences

A coolant injection into the reactor vessel with depressurization of the reactor coolant system (RCS) has been evaluated as part of the evaluation for a strategy of the severe accident management guidance (SAMG). Two high pressure sequences of a small break loss of coolant accident (LOCA) without safety injection (SI) and a total loss of feedwater (LOFW) accident in Optimized Power Reactor (OPR)1000 have been analyzed by using the SCDAP/RELAP5 computer code. The SCDAP/RELAP5 results have shown that only one train operation of a high pressure safety injection at 30,000 s with indirect RCS depressurization by using one condenser dump valve (CDV) at 6  min after implementation of the SAMG prevents reactor vessel failure for the small break LOCA without SI. In this case, only one train operation of the low pressure safety injection (LPSI) without the high pressure safety injection (HPSI) does not prevent reactor vessel failure. Only one train operation of the HPSI at 20,208 s with direct RCS depressurization by using two SDS valves at 40 min after an initial opening of the safety relief valve (SRV) prevents reactor vessel failure for the total LOFW.     

Evaluation of intentional depressurization strategy in Chinese 600 MWe PWR NPP

Intentional depressurization is one of the effective strategies in preventing high-pressure melt ejection (HPME) and direct containment heating (DCH), which is most feasible for the operating nuclear power plants (NPPs) in China. In order to evaluate this strategy of a Chinese 600 MWe PWR NPP, the plant model is built using SCDAP/RELAP5 code. ATWS, SBO, SGTR and SLOCA are selected as the base cases for analysis of intentional depressurization. The results show that opening safety valves of pressurizer manually when the core exit temperature exceeds 922 K can reduce the RCS pressure effectively and prevent the occurrence of HPME and DCH. Several uncertainties such as the operability of safety valves, ex-vessel failure and the transitory rise of RCS pressure are also analyzed subsequently. The results show that the opening of the safety valves can be initiated normally and that opening three safety valves is a more favorable strategy in the event of possible failure of one or more of the safety valves; the probability of ex-vessel failure is reduced after intentional depressurization is implemented; the transitory rising of reactor coolant system (RCS) pressure when the molten core materials relocate to the lower head of reactor pressure vessel (RPV) will not influence the effect of depressurization.     

Application of artificial intelligence techniques in modeling and control of a nuclear power plant pressurizer system

In pressurized water reactor (PWR) nuclear power plants (NPPs) pressure control in the primary loops is fundamental for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral-derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study is two-fold: first, to develop a pressurizer model based on artificial neural networks (ANNs); secondly, to develop fuzzy controllers for the PWR pressurizer modeled by the ANN and compare their performance with conventional ones. Data from a 2785 MWth Westinghouse 3-loop PWR simulator was used to test both the pressurizer ANN model and the fuzzy controllers. The simulation results show that the pressurizer ANN model responses agree reasonably well with those of the simulated power plant pressurizer, and that the fuzzy controllers have better performance compared with conventional ones.     

Effect analysis of the intentional depressurization on fission product behavior during TMLB' severe accident

It has been found that the pressure in the reactor coolant system (RCS) remains high in some severe accident sequences at the time of reactor vessel failure, with the risk of causing direct containment heating (DCH).Intentional depressurization is an effective accident management strategy to prevent DCH or to mitigate its consequences. Fission product behavior is affected by intentional depressurization, especially for inert gas and volatile fission product. Because the pressurizer power-operated relief valves (PORVs) are latched open, fission product will transport into the containment directly. This may cause larger radiological consequences in containment before reactor vessel failure. Four cases are selected, including the TMLB' base case and the opening one, two and three pressurizer PORVs. The results show that inert gas transports into containment more quickly when opening one and two PORVs,but more slowly when opening three PORVs; more volatile fission product deposit in containment and less in reactor coolant system (RCS) for intentional depressurization cases. When opening one PORV, the phenomenon of revaporization is strong in the RCS.     

Functional tests of French safety valves, type SEBIM, for their fitness for use in the primary system of German pressurized water reactors

Several safety requirements are made to the operativeness of the relief and safety valves of the pressurizer of German pressurized water reactors. Reliable pressure limitation and - if necessary - reduction to the required pressure must be warranted by them under any transient plant conditions, in case of operational transients and accidents. In addition, the valves must reliably close again if there are requirements for opening and in the event of malfunction in order to avoid loss of coolant accidents. These different requirements result in the fact that the valves must be able to discharge different media such as hydrogen, steam and water. To enable the valves of the pressurizer to meet all specific requirements made to them, retrofittings and modifications to a different extent are required for German pressurized water reactors. In doing so it must be warranted that the valves used will neither show any instable behaviour due to the different discharge media nor cause any relevant strain produced by pressure waves on the adjacent conduits. For retrofitting of the safety valves of the pressurizer, the French company SEBIM, too, proposes a concept for the protection of the primary circuit against exceeding pressure. To prove the functional reliability of safety valves, type SEBIM, under the thermohydraulic conditions prevailing in German pressurized water reactors, an extensive test programme was carried out on the CUMULUS test facility (true scale [1:1] of the real plant) of Eléctricité de France. Due to the positive results obtained in these tests it is to be stated that the safety valves, type SEBIM, stand for an interesting solution for the protection devices of the primary system of German pressurized water reactors (DWR) against exceeding pressure.     

ACME台架全厂断电事故试验研究

为研究AP型非能动核电厂全厂断电事故下的运行特性，利用大型非能动堆芯冷却系统整体试验（ACME）台架开展了试验研究，分析了主要的试验进程和关键参数的变化特点。研究结果表明：ACME台架全厂断电试验的事故序列及试验现象与已有分析一致，符合预期，试验再现了AP型非能动核电厂全厂断电的事故进程；在整个事故过程中，稳压器水位升高，但未发生满溢，非能动余热排出（PRHR）系统换热功率可与衰变功率达到平衡，堆芯余热可有效载出；堆芯补水箱（CMT）和安全壳内置换料水箱（IRWST）初始条件对非能动余热排出阶段的事故进程具有重要影响，在1列CMT投入失效或IRWST异常等不利初始条件下，模化后的非能动堆芯冷却系统(PXS)仍可满足事故验收准则。