Metastable He deexcitation at semiconductor interfaces

A review is given of the application of metastable deexcitation spectroscopy (MDS) to the study of the interface formation between semiconductors and different materials. In particular we present an overview of the results obtained on nanostructured interfaces, where strain and reaction between the substrate and the overlayer atoms drive the growth mode and the morphology of the system. As prototypical examples we discuss the growth of CaF₂ on silicon and rare earths (Yb, Er) on silicon and gallium arsenide. The mechanisms and chemical reactions which bring to interface formation are examined on the basis of MDS results and their comparison with photoemission.     

AP1000型核电厂主控室内漏示踪气体试验方法简析

本文针对AP1000型核电厂主控室内漏示踪气体试验,在调查了美国相关标准及从事内漏示踪气体试验的公司的技术水平基础上,对浓度衰减法和恒量注入法在AP1000型核电厂应用时各自的优缺点进行了分析,并提出了相应的改进建议。     

上海光源BL15U1束线的SRXRF定量分析

本文介绍了用于同步辐射X射线荧光(XRF)定量分析的基本参数法(FP)和MC模拟法。上海光源(SSRF)硬X射线微聚焦光束线(BL15U1)应用上述两种方法对样品进行定量分析,验证了方法的有效性并用定量分析结果计算了BL15U1光束线部分元素的荧光探测限。实验结果表明,对样品中μg/g量级元素含量的定量分析结果相对误差都在10%以内,而使用MC模拟法可以直观地比较不同参数下的模拟谱与实验谱,辅助实验参数的确定,从而减小参数引起的误差,得到更为准确的结果。此外,对BL15U1探测限的计算表明该光束线具备开展高性能荧光实验的能力。     

实时风险监测系统在田湾核电站的研发与应用

风险监测系统是概率安全分析最重要的应用工具之一,在全球各核电站风险决策领域中得到了广泛应用。本文详细介绍了田湾核电站风险监测模型的研发与管理,系统网络架构与多用户应用、实时监测研发与应用、计划自动导入和计算时效性提升等重要特征,以及在电站的针对性应用方案研究,最后讨论了风险监测系统存在的问题与挑战。     

21世纪环境科学中核分析技术的机会

讨论了21世纪环境研究的若干前沿领域,包括：（1）经济性分析和危险性评估;（2）环境监测和生态学;（3）化学品和环境;（4）能源体系和环境;（5）工业生态;（6）人口和健康。随后探讨了该分析技术在在这些前沿环境研究中的重大机会和挑战,提出应当做好以下工作：（1）充分利用和开发核分析技术的固有特点;（2）加强核分析技术在环境污染物的定量和科学的危险性评估方面的作用;（3）发挥核分析技术在环境分析质量保证体系中的作用;（4）开拓核分析技术在环境污染化学种态及其效应研究中的能力;（5）建立可用于研究新型生物分子标志物及其环境毒理的核分析技术;（6）重视核分析技术在新型污染物的鉴别及其溯源中的应用。     

Application of element correction and personal dose equivalent response to extremity dosimeters used at Korean nuclear power plants

Radiation workers who inspect and repair steam generators during maintenance periods in nuclear power plants (NPPs) have a likelihood of high radiation exposure to their extremities, especially the hands, because of contact with radioactive materials. To estimate the personal dose equivalent, H_p(0.07) to an extremity, it is necessary for workers to wear extremity dosimeters, thermoluminescent dosimeters (TLD), on their fingers. In this article, the element correction and the personal dose equivalent response for two types of extremity dosimeters, Harshaw EXTRAD dosimeters and Panasonic UD‐807 dosimeters, which are currently available at Korean NPPs, were calculated by calibration and irradiation tests. To provide the characteristics of the incident radiation field for contact tasks, the results of a radiation field test for inhomogeneous radiation fields in Korean NPPs were also introduced. Finally, on the basis of the results of calibration, irradiation, and radiation field tests, the application of element correction and personal dose equivalent response to extremity dosimeters for radiation workers at Korean NPPs was evaluated in terms of practical use.     

中国原子能科学研究院回旋加速器创新与发展60年

中国原子能科学研究院（CIAE）自1958年首台回旋加速器成功出束以来,已经历了60余年的回旋加速器创新与发展,并由此带动了我国核科学技术基础研究和应用技术的发展。本文在简要回顾回旋加速器前30年发展历程的基础上,重点阐述后30年围绕紧凑型回旋加速器的科技创新和应用,主要包括100 MeV强流质子回旋加速器、医用小型回旋加速器、质子治疗超导回旋加速器及高功率等时性圆型加速器等多种先进的质子加速器研发。     

核电厂一回路源项和排放源项框架体系研究

我国核电机组堆型众多,来源广泛,这些引进堆型的源项在我国应用中还存在一些问题。源项设计是否合理,直接影响到排放源项的准确性和环境影响评价源项的合理性。本文通过分析不同堆型源项在我国应用中存在的问题,研究如何构建我国核电厂通用的一回路源项和排放源项框架体系,为解决国内核电厂源项计算中长期存在的问题,也为我国华龙一号和CAP1400堆型的源项计算提供技术基础。     

大亚湾核电厂辐射防护最优化工作管理经验

结合大亚湾核电厂当前的运行经验,从责任和组织、理念推广、技术应用、全过程管理等方面介绍了辐射防护最优化的运作体系和经验。大亚湾核电厂对ALARA运作体系的持续改进和完善,使得6台机组降低的集体剂量超过145人·mSv(2013年1月至2015年9月可直接量化统计值),并呈现出下降趋势。     

Auger electron yields induced by channeled ions at grazing incidence

The spectroscopy of Auger electrons induced by channeled ions is discussed by experiments and computer simulations as regards its applicability in surface structure studies. A Ni(110) surface bombarded with 150 keV protons under axial surface channeling and planar channeling conditions is used as an example. It is shown that axial surface channeling provides an excellent surface sensitivity for the application to surface structure analysis and location of adsorbed atoms, whereas planar channeling due to larger grazing angles of incidence to the surface does not. The influence of the impact parameter dependence of the ionization probability on the channeling dips is investigated by means of two different Auger lines: nickel M₂₃VV and L₃VV. The results yield a criterium for the selection of the most suitable Auger transition for the application of this technique. The influence of the mean free path of the induced Auger electrons is examined and the effect of thermal vibrations and surface steps is discussed.     

移动式超声波去污装置在核电站的应用实践

介绍移动式超声波去污装置在核电站的应用实践。根据实例,分析总结了超声波去污装置在核电站去污工作中的工艺条件,并对此类装置的适用性和局限性进行了讨论。     

Simultaneous and multi-criteria optimization of TS requirements and maintenance at NPPs

One of the main concerns of the nuclear industry is to improve the availability of safety-related systems at nuclear power plants (NPPs) to achieve high safety levels. The development of efficient testing and maintenance has been traditionally one of the different ways to guarantee high levels of systems availability, which are implemented at NPP through technical specification and maintenance requirements (TS&M). On the other hand, there is a widely recognized interest in using the probabilistic risk analysis (PRA) for risk-informed applications aimed to emphasize both effective risk control and effective resource expenditures at NPPs. TS&M-related parameters in a plant are associated with controlling risk or with satisfying requirements, and are candidate to be evaluated for their resource effectiveness in risk-informed applications. The resource versus risk-control effectiveness principles formally enter in optimization problems where the cost or the burden for the plant staff is to be minimized while the risk or the availability of the safety equipment is constrained to be at a given level, and vice versa. Optimization of TS&M has been found interesting from the very beginning. However, the resolution of such a kind of optimization problem has been limited to focus on only individual TS&M-related parameters (STI, AOT, PM frequency, etc.) and/or adopting an individual optimization criterion (availability, costs, plant risks, etc.). Nevertheless, a number of reasons exist (e.g. interaction, similar scope, etc.) that justify the growing interest in the last years to focus on the simultaneous and multi-criteria optimization of TS&M. In the simultaneous optimization of TS&M-related parameters based on risk (or unavailability) and cost, like in many other engineering optimization problems, one normally faces multi-modal and non-linear objective functions and a variety of both linear and non-linear constraints. Genetic algorithms (GAs) have proved their capability to solve these kinds of problems, although GAs are essentially unconstrained optimization techniques that require adaptation for the intended constrained optimization, where TS&M-related parameters act as the decision variables. This paper encompasses, in Section 2, the problem formulation where the objective function is derived and constraints that apply in the simultaneous and multi-criteria optimization of TS&M activities based on risk and cost functions at system level. Fundamentals of a steady-state GA (SSGA) as an optimization method is given in Section 3, which satisfies the above requirements, paying special attention to its use in constrained optimization problems. A simple case of application is provided in Section 4, focussing on TS&M-related parameters optimization for a stand-by safety-related system, which demonstrates how the SSGA-based optimization approach works at the system level, providing practical and complete alternatives beyond only mathematical solutions to a particular parameter. Finally, Section 5 presents our conclusions.     

FARO and KROTOS code simulation and analysis at JRC Ispra

The paper summarizes relevant results from the pre- and post-test calculations of fuel coolant interaction and quenching tests performed in the FARO and KROTOS test facilities. The main analytical tools adopted at JRC Ispra are the COMETA and the TEXAS codes. COMETA pre and post-test calculations of FARO Test L-20 as well as an application of the code to KROTOS test facility are presented. The analysis provides the need to account for H₂ generation models into the pre-mixing calculations. In addition salient results from the application of TEXAS to FARO and KROTOS tests are shown.     

In-situ high-energy-resolution X-ray absorption spectroscopy for UO2 oxidation at SSRF

Based on the high-energy-resolution fluorescence spectrometer on the BL14W1 beamline at Shanghai Synchrotron Radiation Facility,an in-situ high-energyresolution X-ray absorption spectroscopy technique,with an in-situ heating cell,was developed.The high-energyresolution fluorescence detection for X-ray absorption near-edge spectroscopy (HERFD-XANES) was tested in a UO2 oxidation experiment to measure the U L3-edge,with higher signal-to-noise ratio and higher-energy-resolution than conventional XANES.The technique has potential application for in-situ study of uranium-based materials.     

Cumulative damage fatigue tests on nuclear reactor Zircaloy-2 fuel tubes at room temperature and 300°C

Cumulative damage fatigue tests were conducted on the Zircaloy-2 fuel tubes at room temperature and 300°C on the modified Moore type, four-point-loaded, deflection-controlled, rotating bending fatigue testing machine. The cumulative cycle ratio at fracture for the Zircaloy-2 fuel tubes was found to depend on the sequence of loading, stress history, number of cycles of application of the pre-stress and the test temperature. A Hi-Lo type fatigue loading was found to be very much damaging at room temperature and this feature was not observed in the tests at 300°C. Results indicate significant differences in damage interaction and damage propagation under cumulative damage tests at room temperature and at 300°C. Block-loading fatigue tests are suggested as the best method to determine the life-time of Zircaloy-2 fuel tubes under random fatigue loading during their service in the reactor.     

Using a data-centric event-driven architecture approach in the integration of real-time systems at DTP2

Integration of heterogeneous and distributed systems is a challenging task, because they might be running on different platforms and written with different implementation languages by multiple organizations. Data-centricity and event-driven architecture (EDA) are concepts that help to implement versatile and well-scaling distributed systems.This paper focuses on the implementation of inter-subsystem communication in a prototype distributed remote handling control system developed at Divertor Test Platform 2 (DTP2). The control system consists of a variety of heterogeneous subsystems, including a client–server web application and hard real-time controllers. A standardized middleware solution (Data Distribution Services (DDS)) that supports a data-centric EDA approach is used to integrate the system.One of the greatest challenges in integrating a system with a data-centric EDA approach is in defining the global data space model. The selected middleware is currently only used for non-deterministic communication. For future application, we evaluated the performance of point-to-point communication with and without the presence of additional network load to ensure applicability to real-time systems. We found that, under certain limitations, the middleware can be used for soft real-time communication. Hard real-time use will require more validation with a more suitable environment.     

The nuclear microprobe at the University of Arizona

A nuclear microprobe has been operational at the University of Arizona since early 1994. It utilizes a magnetic quadrupole doublet (model QL-300 from Microscope Associates, Inc.) with an 11 mm diameter aperture and lens lengths of 6 cm each. The magnetic pole tips are electrically insulated to enable electric rotational alignment and beam rastering by application of varying voltages to the pole tips. Ion beams are obtained from a 5.5 MV model CN, High Voltage Engineering Corp. Van de Graaff accelerator with a Penning type ion source. Present mininum beam spot size is about 2 μm obtained with a 4 MeV H₂⁺ beam with a current of about 40 pA. To date, the instrument has been successfully used to map concentrations of Hg, Cr, and As in rabbit renal slices using PIXE.     

GaN基MOSFET低温特性的实验表征及分析

深空探测活动需要电子元器件在极端低温环境（T<40 K）中能正常使用。基于低温环境下的应用需求,本文研究了GaN基MOSFET在15～300 K温区的低温环境效应。实验结果显示,随着温度逐渐从300 K降低到15 K,饱和漏极电流和阈值电压均增大。低温下,转移特性和输出特性均变好。分析发现,较高的电子迁移率是GaN基MOSFET低温下电特性变化的主要原因。     

Antiproton-nucleus reactions at intermediate energies

Antiproton-induced reactions on nuclei at the beam energies from hundreds Me V up to several Ge V provide an excellent opportunity to study interactions between the antiproton and secondary particles(mesons, baryons and antibaryons) with nucleons. The antiproton projectile is unique in the sense that most of the annihilation particles are relatively slow in the target nucleus frame. Hence, the prehadronic effects do not much influence their interactions with the nucleons of the nuclear residue. Moreover, the particles with momenta less than about 1 Ge V/c are sensitive to nuclear mean field potentials. This paper discusses the microscopic transport calculations of the antiproton-nucleus reactions and is focused on three related problems:(i) antiproton potential determination,(ii) possible formation of strongly bound antiproton-nucleus systems, and(iii) strangeness production.     

核电厂在役检查无损检查资质在我国的实践和探索

本文介绍了核电厂在役检查无损检查资质要求在我国核电厂的实践以及遇到的一些问题,并提出探索性的建议.