中国实验包层模块材料研发进展

聚变堆包层技术是聚变能实现应用的关键技术之一,而材料问题是包层技术的核心问题之一.本文在介绍了目前国际热核聚变实验堆ITER实验包层模块材料选择和中国实验包层模块概念设计中所选材料的性能特点的基础上,重点介绍了国内开展的相关材料研究进展,并阐述了下一步研究中应重点解决的问题.     

Treatment and geological disposal of waste from NET pre-design

Within the European Fusion Technology programs Studsvik RadWaste AB has performed studies on fusion waste treatment and disposal for several years. This paper deals with the treatment and geological disposal of radioactive waste from NET operation and decommissioning. Results from calculations on radioactive waste fluxes for the operation and decommissioning of NET are reported. The calculations are based on the NET predesign report published 1993 and include results for the exchangeable in-vessel and external parts of the machine as well as permanent reactor components. Different aspects of treatment, packaging, transportation, and interim storage of the waste are discussed. The volumes of waste conditioned for final disposal are preliminarily quantified, according to German and Swedish scenarios for radioactive waste disposal. A total repository volume of approximately 45,000 m³ is required in the German Scenario and 35,000 m³ is required in the Swedish Scenario. Results from dose rate calculations for NET waste in final repositories are presented for the Swedish Scenario. This work was financially supported by the Swedish Natural Science Research Council (NFR) and the European Atomic Energy Community, under an association contract between Euratom and Sweden.     

Rating criteria for activated waste from fusion reactors

In the past, Shallow Land Burial (SLB) was considered one suitable solution for the management of fusion activated waste, the other being Recycling. These concepts have influenced the development of low activation materials for fusion (LAMs), having reduced long-term radioactivity. Present European studies, however, do not consider SLB a viable option and concentrate more on Geological Disposal (GD). A classification of activated materials into High-, Medium-, and Low-Level Waste is proposed, taking into account contact dose rates and decay heat levels, in compliance with the GD and Recycling alternatives. This proposal is also consistent with integral criteria to classify LAMs, based on both the short- and long-term radioactive behavior. Applications of these rating criteria to activated components from various fusion designs are shown.     

聚变堆低活化马氏体钢的发展

介绍了国际聚变堆低活化结构材料发展概况及趋势,以及国内发展自己特有的低活化马氏体钢的必要性。介绍了聚变堆结构材料——低活化铁素体/马氏体钢发展的必要性及迫切性,以及目前国际上包括欧洲、日本、美国等在此方面研究的进展概况及发展趋势,最后提出了国内发展自己特有的低活化马氏体钢——CLAM钢的必要性,并对目前的研究进展情况做了介绍。     

法国COGEMA核废物处理中心的环境保护

主要介绍了法国COGEMA集团核废物处理技术,即放射性环境影响、废物控制、空气中放射性含量的监测、水质的监测和保护、土地的恢复和开发等,以及对每一项工作所采取的措施;评价了该集团核废物处理中心的环境保护工作及其经验,以此借鉴国外有关核废物处理和环境保护的先进技术。     

Removal of radioactive isotopes from sewage

Data are cited on the purification of sewage from radioactive isotopes by methods of coagulation and ion exchange.It is shown that by the successive use of the indicated rnethods, low-activity sewage may be purified to the maximum perrnissible concentration (MPC) for all radioactive isotopes. The removal of radioactive isotopes from waste solutions by ion exchange resins is directly dependent on the salt composition of the solutions.Translated from Atomnaya Énergiya, Vol. 18, No. 6, pp. 623–626, June, 1965     

An ensemble approach to sensor fault detection and signal reconstruction for nuclear system control

To efficiently control a process, accurate sensor measurements must be provided of the signals used by the controller to decide which actions to actuate in order to maintain the system in the desired conditions. Noisy or faulty sensors must, then, be promptly detected and their signals corrected in order to avoid wrong control decisions. In this work, sensor diagnostics is tackled within an ensemble of Principal Component Analysis (PCA) models whose outcomes are aggregated by means of a local fusion (LF) strategy. The aggregated model thereby obtained is used for both the early detection and identification of faulty sensors, and for correcting their measured values. The fault detection decision logic is based on the Sequential Probability Ratio Test (SPRT). The proposed approach is demonstrated on a simulated case study concerning the pressure and level control in the pressurizer of a Pressurized Water Reactor (PWR). The obtained results show the possibility to achieve an adequate control of the process even when a sensor failure occurs.     

A Metropolis algorithm combined with Nelder–Mead Simplex applied to nuclear reactor core design

A hybridization of the recently introduced Particle Collision Algorithm (PCA) and the Nelder–Mead Simplex algorithm is introduced and applied to a core design optimization problem which was previously attacked by other metaheuristics. The optimization problem consists in adjusting several reactor cell parameters, such as dimensions, enrichment and materials, in order to minimize the average peak-factor in a three-enrichment-zone reactor, considering restrictions on the average thermal flux, criticality and sub-moderation. The new metaheuristic performs better than the genetic algorithm, particle swarm optimization, and the Metropolis algorithms PCA and the Great Deluge Algorithm, thus demonstrating its potential for other applications.     

高放废物地质处置中的工程材料

凡人类从事于与核材料有关的许多生产、生活活动均可能产生不同活度的放射性废物.高放废物由于具有放射性水平高、发热量大、核素寿命长等特点,其安全处置倍受全球科学家和广大公众所重视.目前深地质处置被国际上公认为处置高放废物的最有效可行的方法.借鉴已有研究成果,我国采用多重工程屏障系统(包括废物固化体、废物罐及其外包装和缓冲/回填材料)和适宜的地质围岩地质体共同作用来确保高放废物与生物圈的安全隔离.参照国际上该领域的研究成果,结合我国处置概念,本文就高放废物地质处置中的工程材料(废物固化体、废物罐、外包装、缓冲材料、回填材料),以及其材料选择、设计要求和研究重点等进行了总结.     

Application of Kelvin Probe to Studies of Fusion Reactor Materials under Irradiation

Recently, the work function （WF） changes in metallic and ceramic materials to be potentially used in future fusion reactors have been examined by means of Kelvin probe （KP）, under He ion irradiation in high energy （MeV） and / or low energy （500 eV） ranges. The results of polycrystalline Ni samples indicate that the 1 MeV beam only induces decrease in the WF within the experimental fluence range; whereas the irradiation of 500 eV beam results in decrease in the WF firstly, then increase till saturation. A dual layer surface model is employed to explain the observed phenomena, together with computer simulation results by SRIM code. Charges buildup on the surface of lithium ceramics has been found to greatly influence the probe output, which can be explained qualitatively using a model concerning an induction electric field due to external field and free charges on the ceramic surface.     

ICF靶中的纳米金属功能材料研究进展

本文介绍了中国工程物理研究院激光聚变研究中心在激光惯性约束聚变（ICF）和强辐射源材料研究中涉及到的一些纳米金属功能材料的最新研究进展。主要包括自悬浮定向流金属纳米粉末材料制备与性能研究,介质阻挡放电金属纳米粉末表面包覆研究,真空热压成型的纳米晶体材料研究,以及低密度高孔隙率的泡沫镍金属材料、纳米多孔Cu材料和Au泡沫材料研究;在团簇材料、纳米成型材料研究方面,涉及到了过渡金属、贵金属小团簇材料的几何构型和静电极化率特性的理论模拟研究,以及三角形、六边形、棒状、立方体等特殊纳米结构和形状的Ag、Au金属纳米激光X光转换材料研究。     

Activation characteristics of candidate structural materials for a near-term Indian fusion reactor and the impact of their impurities on design considerations

Activation analyses play a vital role in nuclear reactor design.Activation analyses,along with nuclear analyses,provide important information for nuclear safety and maintenance strategies.Activation analyses also help in the selection of materials for a nuclear reactor,by providing the radioactivity and dose rate levels after irradiation.This information is important to help define maintenance activity for different parts of the reactor,and to plan decommissioning and radioactive waste disposal strategies.The study of activation analyses of candidate structural materials for near-term fusion reactors or ITER is equally essential,due to the presence of a highenergy neutron environment which makes decisive demands on material selection.This study comprises two parts; in the first part the activation characteristics,in a fusion radiation environment,of several elements which are widely present in structural materials,are studied.It reveals that the presence of a few specific elements in a material can diminish its feasibility for use in the nuclear environment.The second part of the study concentrates on activation analyses of candidate structural materials for near-term fusion reactors and their comparison in fusion radiation conditions.The structural materials selected for this study,i.e.India-specific Reduced Activation Ferritic-Martensitic steel(IN-RAFMS),P91-grade steel,stainless steel 316 LN ITER-grade(SS-316 LN-IG),stainless steel 316 L and stainless steel 304,are candidates for use in ITER either in vessel components or test blanket systems.Tungsten is also included in this study because of its use for ITER plasma-facing components.The study is carried out using the reference parameters of the ITER fusion reactor.The activation characteristics of the materials are assessed considering the irradiation at an ITER equatorial port.The presence of elements like Nb,Mo,Co and Ta in a structural material enhance the activity level as well as the dose level,which has an impact on design considerations.IN-RAFMS was shown to be a more effective low-activation material than SS-316 LN-IG.     

放射性废物处置安全全过程系统分析中的指标

以往放射性废物处置的安全评价中通常使用放射性安全指标(即剂量和危险),随着放射性废物处置安全全过程系统分析这一概念的提出,辅助指标已成为评价中的一个重要组成部分。本文介绍了安全全过程系统分析中所使用指标的发展、分类和相应标准等。依评价对象不同,辅助指标通常分为安全指标和性能指标,有些组织还提出了安全功能指标;与上述指标相对应的用于比较的标准分别为参考值、指标标准和安全功能指标标准。将处置系统划分为不同库室时,指标还可分为“包容物和浓度”相关指标、“通量”相关指标和“屏障状态”相关指标三类。建议我国尽快开展放射性废物处置的安全全过程系统分析工作,建立完善的指标体系,选取适当的评价指标,并基于我国放射性废物处置的场址特性确定相应的标准,以期实现安全和防护的最优化。     

放射性废物处置安全全过程系统分析及有关问题的探讨

本文根据IAEA第SSG-23号安全导则,对放射性废物处置安全全过程系统分析及其在英国、法国、美国、芬兰、瑞士、瑞典等国家放射性废物处置中的应用情况作了概括性的介绍。结合我国放射性废物处置管理的现状,对我国处置场的环境影响评价和安全分析中存在的主要问题进行了探讨。为促进我国安全全过程系统分析工作的全面开展,建议加快制定相关标准,将“安全全过程系统分析”作为我国放射性废物处置的许可条件,在景象开发、长期演变、坚稳性、不确定性、管理系统等方面加强研究。     

ITER氚增殖实验包层设计研究进展

国际热核实验反应堆(ITER)为人类开发聚变能提供重要的物理和工程技术实验平台,ITER氚增殖实验包层模块(TBM)技术是必须掌握的关键技术.参与ITER计划的成员国根据本国商用演示堆包层发展策略,分别提出了各自的实验包层概念,以便在ITER运行期间进行实验.本文对ITER-TBM目前已经开展和正在进行的主要设计研究工作进展进行总结,介绍了各方提出的设计方案、支撑设计的相关技术研究进展,以及合作实验窗口的分配现状.     

Need for and requirements for a neutron irradiation facility for fusion materials testing

The construction and operation of an intense 14-MeV neutron source is essential for the development and eventual qualification of structural materials for a fusion reactor demonstration plant (DEMO). Because of the time required for materials development and the scale-up of materials to commercial production, a decision to build a neutron source should precede engineering design activities for a DEMO by at least 20 years. The characteristic features of 14-MeV neutron damage are summarized including effects related to cascade structure, transmutation production, and dose rate. The importance of a 14-MeV neutron source for addressing fundamental radiation damage issues, alloy development activities, and the development of an engineering database is discussed. For these considerations, the basic requirements and machine parameters are derived.     

高放废物处置库选址中的水文地质特性评价

根据国内外研究经验,综述高放废物地质处置库选址不同研究阶段水文地质特性评价的方法和作用,并将评价方法分为区域、地区和场址3个阶段水文地质调查来讨论。同时,介绍了我国高放废物地质处置场地水文地质特性评价研究现状。     

高放废物的处理处置方法

介绍了高放废物处理处置方法，比较了其各自的优缺点，指出深地质处置是处置高放废物的合适方法。     

A high-flux accelerator-based neutron source for fusion technology and materials testing

Advances in high-current linear-accelerator technology since the design of the Fusion Materials Irradiation Test (FMIT) Facility have increased the attractiveness of a deuteriumlithium neutron source for fusion materials and technology testing. This paper discusses the conceptual design of such a source that is aimed at meeting the near-term requirements of a high-flux high-energy International Fusion Materials Irradiation Facility (IFMIF). The concept employs multiple accelerator modules providing deuteron beams to two liquid-lithium jet targets oriented at right angles. This beam/target geometry provides much larger test volumes than can be attained with a single beam and target and produces significant regions of low neutron-flux gradient. A preliminary beam-dynamics design has been obtained for a 250-mA reference accelerator module. Neutron-flux levels and irradiation volumes were calculated for a neutron source incorporating two such modules, and interaction of the beam with the lithium jet was studied using a thermal-hydraulic computer simulation. Approximate cost estimates are provided for a range of beam currents and a possible facility staging sequence is suggested.This work was supported by Los Alamos National Laboratory Program Development Funds under the auspices of the U.S. Department of Energy.Supported in part by an appointment to the U.S. DOE Fusion Energy Postdoctoral Research Program administered by Oak Ridge Associated Universities.     

西北处置场低、中放固体废物处置实践

介绍了我国西北处置场的基本情况,西北处置场低、中放固体废物接收、处置的组织机构及管理体系,工艺技术,辐射防护及环境监测,以期为我国放射性废物处置工程提供借鉴和支持。