健康效应模型在核电站事故后果分析中的应用

健康效应模型是核电站事故后果分析中使用的重要模型之一。健康效应模型的有效性，直接影响到后果评价的可信性，从而影响到为缓解事故后果、保护公众健康而采取的应急措施的有效性。本研究在ＮＵＲＥＧ／ＣＲ４２１４模型的基础上，建立了适合于我国核电站事故后果分析的健康效应模型参数，并将该模型应用于广东大亚湾核电站的事故后果分析中，研究中选择香港居民为对象，计算和分析了大亚湾核电站的严重事故对香港居民带来的健康风险的增加。计算结果表明，该电站对香港地区带来的健康风险很低。     

EDXRF中吸收增强效应实验的指数刻度方法初探

针对EDXRF技术分析矿石中铁元素含量问题,提出了一种新的刻度方法。利用EDXRF分析技术得到了钛、钒、镍、铜、锌对铁元素的吸收增强效应。结果表明,Fe元素Kα系X射线的归一计数率（RFe）与含量（WFe）之间的关系表现为双曲线形式。根据前期研究结果,建立了一种基于最小二乘回归算法的指数拟合工作曲线刻度方法,同时实现了对基体效应的有效校正。通过对3种铁矿石中铁元素含量计算结果表明,与传统的多元回归刻度方法相比,指数刻度方法有较好的计算结果。     

体源HPGeγ全能峰效率刻度的研究

本工作研究不同基体、不同几何体源的HPGeγ全能峰探测效率刻度方法。考虑了圆柱形体源的自吸收及级联符合相加效应对探测效率的影响,探索性提出了解决级联符合效应校正的新方法。     

核电建设的学习效应和标准化效应

介绍了学习效应和标准化效应，分析了其对核电经济性的影响程度，并提出了发挥学习效应和标准化效应，提高核电经济性的思路。还实际分析得到我国核电建设中的学习率高于国际平均水平。     

γ级联衰变符合相加效应解析修正

利用符合相加修正解析计算方法,以¹⁵²Eu为例,研究了符合相加效应对探测器效率刻度与活度测量的影响。结果表明:近距离测量放射性样品时,级联符合相加效应非常明显;本课题探讨的解析修正方法能有效地对该效应进行修正。     

固体核径迹氡探测器刻度系数及其受大气压强影响的蒙特卡罗模拟计算

利用氡及其子体在测量容器中的位置分布和衰变时α粒子出射方向的随机性，编制了固体核径迹氡探测器刻度系数的蒙特卡罗模拟计算程序。对不同尺寸的圆柱形容器和不同类型探测片(CR-39、LR-115)氡探测器的刻度系数进行了计算，模拟计算结果与已有的实验数据符合较好。计算了大气压强(假定温度不变)对刻度系数的影响。当大气压强下降至标准压强的0．65时，LR-115型探测器的刻度系数增大约31％，CR-39型探测器的刻度系数增大约17％。     

三双符合比-切伦科夫方法中β核素壁效应的影响

为分析三双符合比-切伦科夫(TDCR (Triple-to-double Coincidence Ratio)-切伦科夫)方法中壁效应对效率计算的影响。首先，对β粒子在溶液到瓶壁过程的输运进行分段分析，得到不同能量的粒子在不同材料中的沉积能谱与所产生的切伦科夫光子数的关系式，并对其进行了计算上的简化，进一步完善TDCR-切伦科夫效率的计算模型；之后利用Geant4计算了β在介质和瓶壁中的沉积谱，得到考虑了壁效应的切伦科夫光子数与β能量的关系曲线以用于对核素的效率计算；最后开展了多种纯β核素的实验测量以验证考虑壁效应后的计算模型的准确性。结果显示：考虑壁效应后的TDCR-切伦科夫方法与液闪方法的结果在不确定度范围内一致，且对高能β核素，其结果与液闪之间的相对偏差由原方法的0.47%降低至0.02%(⁹⁰Y),0.64%降低至-0.16%(32P)，表明考虑壁效应后的TDCR-切伦科夫方法对高能β核素的测量结果更准确。     

基于Bamboo-C软件的压水堆10B丰度计算方法研究

在压水堆功率运行过程中，由于燃耗效应和硼化效应的原因，一回路硼酸溶液中10B的丰度会随时间不断地发生变化，而核电厂又无法提供10B丰度的实时测量值，从而导致核设计程序对临界硼浓度的计算值在循环中期低于实测值。因此，为了降低堆芯一回路临界硼浓度计算值与实测值之间的偏差，本文基于西安交通大学核工程计算物理实验室（NECP）自主研发的Bamboo-C软件给出了10B丰度的计算方法，该方法能够同时考虑燃耗效应和硼化效应对临界硼浓度的影响。采用本文10B丰度计算方法，对福清核电厂M310机组功率运行历史进行跟踪模拟，并且将一回路临界硼浓度和10B丰度的计算值与实测值进行对比验证。验证结果表明，本文10B丰度计算方法能够改善堆芯临界硼浓度的数值计算结果，具备工业应用的条件。      

超临界水通道内压降特性分析

超临界水冷堆是以超临界水作为冷却剂和慢化剂的第4代核能系统之一，超临界水在拟临界区附近剧烈的物性变化会给通道内的压降特性带来影响。本文分析了超临界条件下重力压降、加速压降和摩擦压降的特点，并对具体的计算方式提供了一些建议和参考：重力压降需考虑沿程的积分效应；基于隐式PKN公式得到了显式PKN公式，用于求解等温流动摩擦系数；采用CFD数值分析工具比较了超临界条件下不同摩擦关系式的异同，发现Kirillov公式与CFD计算结果较为接近。     

典型光电子器件辐射效应数值分析与试验模拟方法研究

选取Si太阳电池与线阵CCD器件，进行了光电器件辐射效应的数值分析与模拟试验方法研究。分析了光电器件电离效应和位移损伤机理，利用二维器件模拟软件MEDICI，模拟了1MeV电子对n／p型硅太阳电池主要输出参数的影响，包括开路电压Voe、短路电流Isc和最大输出功率Pmax.在一定范围内，计算结果与文献实验数据符合较好。建立了线阵CCD器件辐照效应离线测量系统。利用^60Coγ源，进行了商用器件的总剂量效应试验，给出了暗电流信号和饱和电压信号的变化曲线。     

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.     

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。     

Investigations on landmine detection by BF3 detector

Experiments were carried out to investigate the possible use of neutron backscattering for the detection of polyethylene (PE) sample buried in the soil. In detection of landmine by neutrons, the neutron detector and its shield play an important role. In this paper, the effects of graphite, heavy water, polyethylene and boric acid moderators on the flux of back scattered neutrons were investigated. We have also experimentally verified the effect of BF3 detector shield and obtained good agreement with theory.     

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.     

Assessment of radioactivity levels in some oil samples from the western desert, Egypt

Distributions of natural gamma-emitting radionuclides were determined in 93 oil samples collected from some petroleum fields in the western desert of Egypt. The radioisotope activities in the area under investigation lay in the range of (21 ± 4) to (38 ± 13) Bq?L-1 for 226Ra, (9 ± 2) to (15 ± 5) Bq?L-1 for 232Th, and (154 ± 28) to (303 ± 54) Bq?L-1 for 40K. The mean values were 27, 12, and 201 Bq?L-1, respectively. Among oils, variations in radionuclide ac- tivities could be on account of differences in TDS, HCO3, and Ba, with high or low pH. In this environment, oil prop- erties differently affected the mobilization of natural radionuclides. The range of 226Ra variation had been compared with available data from other countries. The calculated absorbed dose rate ranged from 22.33 to 32.66 nGy?h-1 in lo- cation (B) and (E) respectively, which was less than the accepted value.     

Preparation and properties of 117m Sn(IV)-TTHMP in in-vitro and in small animals

In this work,TTHMP was synthesized and labelled with 117m Sn.The preparation conditions,stability and lipophilicity of 117m Sn(IV)-TTHMP were investigated.Biodistribution of the complex in rabbits and mice was studied.It was found that the quantity of TTHMP and pH value of the prepararion solution had vital effects on the labeling yield of 117m Sn(IV)-TTHMP.It was also found that 117m Sn(IV)-TTHMP was hydrophilic and stable at room temperature and 37℃ in open air 117m Sn(IV)-TTHMP showed unexpectedly high bone uptake and bone-to-blood ratio in the animals.This made it potentially useful as an reagent for skeletal scintigraphy and radiotherapy of bone tumors.     

The role of AGFA high-energy CR in the calibration and quality control of multileaf collimators （MLC）

Linear accelerators equipped with multileaf collimators （MLC） are becoming more common and are widely used in the intensity-modulated radiotherapy （IMRT）. There is an imperative need to ensure the commissioning specification of the linear accelerators for the sake of quality assurance （QA） and quality control （QC）. This paper is aimed to investigate the role of AGFA high-energy CR （Computed Radiography） in calibrating dynamic multileaf collimators and evaluating the accuracy of the leaf position. The result shows that AGFA high-energy CR can easily and conveniently be used to calibrate MLC and verify its position. Hence, the application of AGFA high-energy CR is proved to be an accurate and time-saving method for routine MLC QC, especially when MLC calibration adjustments are required.     

Gamma radiation levels in the ambient environment of the QNPP Base

Monitoring results of gamma dose rate level in 1992～2004 in the ambient environment of the Qinshan Nuclear Power Plants(QNPP)Base,the northeast of Zhejiang Province,are reported in this paper.It is shown that the gamma dose rate of five monitoring sites of 2.5 km to QNPP Base is 84～113 nGy/h,with an average of 96 nGy/h in the 13 years.The average value is close to the background level of 93 nGy/h prior to operation of the QNPP Base,and is lower than the monitoring result of 101 nGy/h at the reference site in Hangzhou City.Within 50 km from the QNPP Base,the cumulative dose rate of the thermoluminescent dosimeter(TLD)is 90 nGy/h,which is lower than the back- ground level of 111 nGy/h.