广东省核电站核事故场外后果预测评价系统

广东省核电站核事故场外后果预测评价系统（GNARD2．0）是一个核电站事故场外辅助决策计算机软件系统,该系统具有在线和实时评价和预测事故后果的能力,能够计算风场,放射性物质浓度和剂量,进而给出超过干预水平的区域及区域内的人口,应急设施等信息,并能对应急防护行动实施进程进行模拟和计算,得出可防止剂量以评价行动的有效程度,本文简要介绍了该系统的软硬件组成和后果评价模式,总结了系统开发经验,并对系统的未来发展方向进行了讨论。     

一种针对多机组事故的操作干预水平应急决策辅助系统

操作干预水平(OIL)是指对应于某一特定公众防护行动通用干预水平的易于测量的辐射量,用于在核事故期间直接与监测结果比较给出应急防护行动建议。福岛核事故后,我国核应急准备和响应向着多机组方向发展,本研究提出了一种针对多机组事故优化的OIL应急决策辅助系统,将每个机组发生的事故后果进行单独计算和评价,最后将它们对环境辐射后果的贡献进行迭加并代入原先计算公式中,即得到多机组事故下的OIL值。在优化方法的基础上,系统实现了单机组和多机组事故情景下的OIL查询、计算、修正以及后续的应急辅助决策功能。目前,该系统已应用于秦山、田湾、宁德、阳江等核电基地,其模式和功能在实际应用中得到了不断验证和完善,为核事故应急提供了重要的辅助决策手段和工具。     

事故状态评价在核事故应急决策中的应用

事故评价是核电厂应急状态下进行防护行动决策的重要技术基础.事故评价包括事故状态评价和事故后果评价两个方面.本文主要介绍事故状态评价技术在核事故应急决策中的应用情况.     

江苏省核应急管理与指挥决策支持系统的研究

在核应急响应期间,为确定公众防护的正确决策,需对大量场内、外的数据和信息进行科学分析和统一管理,并从大量的核应急原始数据和加工、处理后得到的信息中挖掘对决策有用的信息,以便捷直观的方式提供给决策者。本文设计了一个基于网络的、指挥及响应信息通畅的计算机管理信息系统--江苏省核应急管理与指挥决策支持系统,能解决数据形式和结构复杂、信息形式缺乏规范、外部接口多、用户需求多样、信息处理时间短、输出直观性要求高等难题。该系统综合了后果评价和预测子系统、应急信息子系统、文件处理子系统、地理信息子系统和操作干预水平计算子系统,能在事故期间处理来自核电厂场内、外的各种信息,为应急管理及指挥决策及提供技术支持,提高应急管理和指挥决策的科学性及技术含量。     

集成化核电厂核应急指挥与决策支持系统开发

集成化核电厂核应急指挥与决策支持系统用于核电厂的应急指挥、工况评价、环境影响预测评估、决策支持和应急数据管理等。该系统实时采集机组工艺运行、气象、环境监测等基础监测数据,通过画面组态显示机组主要核安全参数,并基于实时数据和手动输入,开展应急状态等级辅助判断、堆芯损伤评估、源项计算、环境影响预测分析、操作干预水平计算等。系统针对事故不同阶段,如:启动应急时刻、放射性释放前、放射性释放后,分别建立单独的防护行动分析模型,开展不同阶段的决策支持。系统通过Web GIS的方式,对主要的应急资源设施、应急评价结果(等剂量曲线、防护行动区域等)在地图上进行直观显示。本文主要介绍了该系统的业务流程、功能模块设计、开发方案设计,以及主要应急评价模型等。     

乏燃料事故源项估算方法研究

福岛事故之后乏燃料的安全问题受到广泛关注。本文介绍一自主开发的应急辅助决策软件STEM中的乏燃料事故源项估算模块。利用美国核管理委员会(NRC)开发的核电事故后果分析软件RASCAL 4.2与STEM分别对假定事故情景进行计算,结果验证了STEM的正确性。STEM乏燃料事故源项估算模块可为核电厂的乏燃料事故后果评价提供参考。     

随机游走大气扩散模型在核事故应急中的开发和应用

烟羽浓度预测是核事故早期应急响应放射性后果评价系统的主要内容之一.描述了大气扩散本身随机的特点,介绍了自行开发随机游走大气扩散模型Random Walk,并与现有欧共体开发的核应急决策支持系统RODOS中的拉格朗日烟团模型RIMPUFF进行比较验证.结果表明,两者计算结果相当吻合,但Random Walk计算出的烟羽范围比RIMPUFF计算出的稍小.随机游走大气扩散模型Ran-dom Walk能够较好的模拟核事故发生条件下的大气扩散过程,可以作为核事故应急决策系统的一个大气扩散模块,为早期应急和后果评价提供更接近实际的信息.     

秦山核电厂全厂断电事故厂外后果分析

采用MELCOR和MACCS程序对秦山核电厂全厂断电事故的源项和厂外后果进行了计算。该事故会引起厂外群体受到较大剂量的放射性照射，但剂量不足以引发早期确定性健康效应。并对可能采取的应急防护行动进行评估，确定最佳防护措施为：安全壳泄漏阶段实施隐蔽；若安全壳超压失效无法避免，应急计划区内应立即实施撤离。     

核事故后果的计算机评价模式现状与新动向

近 2 0年来 ,核事故后果评价技术有了很大的发展。本文简要综述了 IRPA-1 0会议“核事故及其辐射”专题的内容。因为切尔诺贝利核事故对环境和人的影响深远 ,所以首先介绍了事故后较长时期内环境污染和健康效应的调查及数据收集工作。重点介绍了世界上具有代表性的 3个事故应急评价与决策支持系统 :RODOS、WSPEEDI、ARAC的基本功能和新动向 ,强调了先进计算机技术在后果评价中的作用。     

基于严重事故剂量后果的堆芯重要核素选择

用于事故放射性后果评价的事故源项与堆芯源项密切相关,而通用的堆芯源项程序,如ORIGEN的计算结果包含几百个甚至更多的核素,如何在大量核素中筛选出重要核素,对于简便、准确地进行放射性后果评估具有重要意义。通过对事故后核素迁移至环境的跟踪,评价每个核素对最终放射性后果的贡献。结果显示30～50个核素的剂量贡献即可包络95%以上的剂量后果,这些核素可作为计算的基准,也是堆芯源项核素选择的依据。计算方法对剂量后果评价具有重要的参考价值。     

Identification of radiation treatment of wheat （Triticum aestivum. L）and rice （Oryza sativa. L） samples using thermoluminescence of contaminating minerals

Food irradiation is gaining popularity worldwide and this technology is important to improve quality and reduce the post harvest losses of food. Because of the rapid commercialization of irradiated foods throughout the world, compliance of different regulations relating to use of technology in different countries and demand of consumers for clear labelling of irradiated foods, there is need for the development of analytical methods to detect radiation treatment of food. Among several methods studied so far, thermoluminescence （TL） is an important method that can be used to find out the irradiation history of food that contain even a very minute amount of dust particles. In this study, the irradiated and unirradiated wheat and rice samples were analyzed using the TL method. The samples were purchased from the local market of Peshawar and irradiated to radiation doses of 0.5 and 1.0 kGy using Co-60 gamma irradiator at the Nuclear Institute for Food and Agriculture （NIFA）, Peshawar. The mineral contaminants were isolated by jet water, ultrasonic treatment, and density gradient. TL glow curves of the isolated minerals from irradiated and unirradiated samples were recorded between the temperature ranges of 50-500℃ using a TL reader. Generally, the glow curves for irradiated samples showed much higher TL intensities （TL1） than the unirradiated samples. The results were normalized by rerradiation of mineral samples to gamma-ray dose of 1.0 kGy followed by determination of the second glow curves （TL2）. The ratio of the area of first glow curve to that of second glow curve （TL1/TL2） was calculated for selected temperature intervals and compared with the recommended values for unirradiated and irradiated samples. Finally, the shapes of the glow curves for irradiated and unirradiated samples were also analyzed. On the basis of these results （comparison of TL-intensities, TL1/TL2 ratios and shapes of the glow curves）, all the irradiated and unirradiated samples of wheat and rice were unequivocally identified.     

有效探测面积大于1000 cm2的正比计数器测量系统性能测试

为对自制的活性面积高达1 000 cm²的大面积源进行表面发射率定值,同时作为现有2πα、2πβ表面发射率标准装置能力的扩充,研制了一套内置式大面积2π多丝正比计数器测量系统,并利用活性区直径为8 mm的²⁴¹Am点源及活性区面积为10 cm×15 cm的大面积²⁴¹Am和⁹⁰Sr-⁹⁰Y源对其进行计量学性能测试。结果表明：计数器内计数响应均匀性优于±0.4%,有效探测面积达1 400 cm²;所得²⁴¹Am源高压坪曲线的坪长为1 400 V,坪斜为0.27%/100 V,坪区内计数变化为0.87%;⁹⁰Sr-⁹⁰Y源高压坪曲线的坪长为300 V,坪斜为0.75%/100 V,坪区内计数变化为0.80%;10次测量重复性好于0.4%,8 h内短期稳定性好于0.3%,1 a内长期稳定性好于0.8%。     

Preparation of Zn/TiO2 powder and its photocatalytic performance for oxidation of P-nitrophenol

Zn-doped TiO2 catalysts were prepared using a sol-gel method and characterized by XPS,UV-Vis, BET, XRD in this study. Under the irradiation of simulant sunlight, the photocatalytic activity for the degradation of p-nitrophenol was studied too. After irradiation for 2.5 h, the degradation percentage of p-nitrophenol could rise to more than 80 %. The results showed that the spectrum absorption band edge of Zn/TiO2 powder does not broaden obviously comparing with pure TiO2 powder. Zinc exists as Zn （11）. When calcined at 973 K, there is a new phase as ZnTiO3 in Zn/TiO2 catalyst. The order of photocatalytic activity of Zn/TiO2 catalysts calcined at different temperatures for p-nitrophenol is 773 K 〉 673 K 〉 873 K 〉 573 K 〉 973 K and the photocatalytic activity of Zn/TiO2 catalyst calcined at 773 K is better than TiO2 catalysts heated at the same temperature, and outclasses that of commercial TiO2 catalyst. It also showed that the photocatalytic degradation of p-nitrophenol follows first-order kinetics under the irradiation of simulant sunlight.     

Current status of radiation therapy for prostate cancer

Radiotherapy for the treatment of prostate cancer has been extensively explored in the past. Along with the comprehensive understanding of the biology of prostate cancer and rapid advances in terms of technology, the out- come of treatment for the patients with prostate cancer has improved. The authors review radiotherapy as the primary treatment for the disease, with particular emphasis on the technological advances from both the radiobiological and radiophysics aspects. Nonconventional fractionated irradiation like hyper- or hypo-fractionation has been imple- mented in the clinic, the final results still need to be confirmed in the future. Technological advances like IMRT, IGRT, in the last two decades have significantly improved the delivery of external radiotherapy to the prostate. This has re- sulted in an overall increase in the total dose that can be safely delivered to the prostate, which has led to modest im- provements in the biochemical outcome. However, establishing the standard therapy for prostate cancer remains con- troversial. It is hoped that the next decades will bring continued advances in the development of biologicals that will further improve current clinical outcomes.     

The control system for SSRF injection and extraction

This paper introduces the injection and extraction control system design for SSRF,which is a distributed control system aimed at stability and reliability of the pulse power supplies,PPS(Personnel Protection System)and MPS(Machine Protection System).The hardware environment is mainly based on PLC(Programmable Logic Con- troller),and ARM(Advanced RISC Machine)is also applied for studying stability of the power supplies.WinCC and EPICS(Experimental Physics and Industrial Control System)have been selected as the platforms of SCADA(Super- visory Control and Data Acquisition).For unifying the interfacing to the control computer,all front-end equipments are connected via Industrial Ethemet.     

Interaction between uranium and humic acid (Ⅰ): Adsorption behaviors of U(Ⅵ) in soil humic acids

The adsorption behaviors of uranium on three soil humic acids (HAs), which were extracted from soils of different depths at the same site, were investigated under various experimental conditions. The adsorption results showed that U(Ⅵ) in solutions can be adsorbed by the three soil HAs, with the order of FHA (HA from 5 m depth of soil) ＞SHA (HA from the surface) ＞THA (HA from 10 m depth of soil) for adsorption efficiency in each desirable condition, and the adsorption reached equilibrium in about 240 min. Although the maximum adsorption efficiency was adsorption could be described with Langmiur isotherm or Freundlich isotherm equation. The L/S (liquid/solid, mL/g)ratio and pH were important factors influencing the adsorption in our adsorption system besides uranium concentration. The adsorption efficiency decreased with the increase of the L/S ratio and pH at the pH range of 2.0-3.0 for SHA and THA or 2.5 - 6.0 for FHA. However, no significant difference in adsorption of U(Ⅵ) was observed at the experimental temperature. All the results implied that humic substances have different characteristics in samples even collected at the same site.     

水平管内含空气蒸汽强制对流冷凝换热模型研究

为研究含空气蒸汽在水平管内强制对流冷凝换热特性,基于对传热传质过程的分析,建立了管内为环状流与波状流条件下的流动冷凝换热模型。从潜热、显热和液膜3个环节对整个换热过程进行建模,最终得到计算局部冷凝换热系数的理论关系式。模型预测结果与实验数据的对比表明,二者相对偏差在±20%以内,验证了该换热模型的准确性与适用性。通过进一步的研究发现：从换热管入口至出口,随着冷凝的进行,管内换热主要热阻由液膜热阻向气液界面的凝结热阻转变;主流气体对流换热过程基本可忽略。     

Information for authors

<正>1.NUCLEAR SCIENCE AND TECHNIQUES(NST),a bimonthly journal,is devoted to all aspects of nuclear science and technology,theoretical or experimental.Its special interest lies in the subjects of synchrotron radiation science and technology;low energy accelerators,radiation technology and applications;radiochemistry,radiopharmaceuticals and nuclear medicine;nuclear electronics and instrumen-     

PLASMA SCIENCE AND TECHNOLOGY AUTHOR INDEX TO VOLUME 16(2014)

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Web Services interface of SSRF archive data analysis system

Accelerator database stores various static parameters and real-time data of accelerator. SSRF (Shanghai Synchrotron Radiation Facility) adopts relational database to save the data. We developed a data retrieval system based on XML Web Services for accessing the archive data. It includes a bottom layer interface and an interface applicable for accelerator physics. Client samples exemplifying how to consume the interface are given. The users can browse, retrieve and plot data by the client samples. Also, we give a method to test its stability. The test result and performance are described.