浮动核电站跨界转运的安全和法律问题初步研究

浮动核电站具有模块化、多用途、可移动、运行灵活、适应性强等优势,受到了国际社会的广泛关注,具有广阔的应用前景和发展空间。然而,浮动核电站由于特殊的海外部署场景和可移动特性,不可避免地面临着跨越主权边界转运的安全和法律问题。结合浮动核电站不同的海外部署场景,重点对浮动核电站在不同部署场景下跨界转运可能面临的安全和法律问题进行梳理总结和讨论分析,并从法律、安保和应急层面提出可能的解决方案建议,对浮动核电站跨界转运相关的国际公约和规则制定具有一定参考意义。     

核电站保护屏障的监护神——核电站辐射监测系统(RMS)概述

为确保核电站运行安全,防止核电站正常运行或事故状态下放射性物质泄漏外逸,在核电站的设计和建造中,就考虑到对核电站进行四重保护屏障的设计,而核电站辐射监测系统则是确保四重屏障核安全的重要措施之一。通过对核电站辐射监测系统(RMS)的介绍,使人们对核电站保护屏障的完整性和有效性有一定的了解,对核电安全性的认识进一步提高。     

Seismic re-evaluation of nuclear facilities worldwide: overview and status

Existing nuclear facilities throughout the world are being subjected to severe scrutiny of their safety in the event of an earthquake. In the United States, there have been several licensing and safety review issues for which industry and regulatory agencies have cooperated to develop rational and economically feasible criteria for resolving the issues. Currently, all operating nuclear power plants in the United States are conducting an Individual Plant Examination of External Events, including earthquakes beyond the design basis. About two-thirds of the operating plants are conducting parallel programs for verifying the seismic adequacy of equipment for the design basis earthquake. The U.S. Department of Energy is also beginning to perform detailed evaluations of their facilities, many of which had little or no seismic design. Western European countries also have been re-evaluating their older nuclear power plants for seismic events often adapting the criteria developed in the United States. With the change in the political systems in Eastern Europe, there is a strong emphasis from their Western European neighbors to evaluate and upgrade the safety of their operating nuclear power plants. Finally, nuclear facilities in Asia are also being evaluated for seismic vulnerabilities. This paper focuses on the methodologies that have been developed for re-evaluation of existing nuclear power plants and presents examples of the application of these methodologies to nuclear facilities worldwide.     

Low-capacity nuclear power: questions and answers

Low- and medium-capacity nuclear power plants for distributed power generation will play a large role at the present stage. The need for such plants in our country solely for supplying electricity to the northern regions will be at least 20 GW(e). One of the most promising developments of nuclear energy sources for autonomous heat and power generation is the Uniterm low-capacity plant with a water-cooled and -moderated reactor facility, where the rich experience in developing and operating domestic propulsion nuclear power facilities is used. It possesses unique user properties and meets the present-day requirements for safety, reliability, and ecological cleanliness.     

Operational experience and safety experiments with the AVR power station

The AVR 15 MWe experimental nuclear power station in Jülich, which has been in operation since 1967, is the first power station with a pebble-bed high-temperature reactor. Succeeding HTR plants, in particular the smaller HTR-Module and HTR-100 facilities, have been developed on the basis of the AVR concept and experience gained during many years' operation.Operating results to date have confirmed the pebble-bed concept. Despite utilization of the plant for experimental purposes, mean time availability since 1967 has amounted to 67.5%. The inherent safety properties have been demonstrated in overall plant tests. In the current experimental programme, further experiments with the power plant will realistically demonstrate that the loss of coolant accident neither endangers the environment nor the plant itself.     

Consequence analysis for nuclear reactors,Yongbyon

Since the Fukushima nuclear power plant accidents in 2011, there have been an increased public anxiety about the safety of nuclear power plants in Korea. The lack of safeguards and facility aging issues at the Yongbyon nuclear facilities have increased doubts. In this study, the consequence analysis for the 5-MWe graphite-moderated reactor in North Korea was performed. Various accident scenarios including accidents at the interim spent fuel pool in the 5-MWe reactor have been developed and evaluated quantitatively. Since data on the design and safety system of nuclear facilities are currently insufficient, the release fractions were set by applying the alternative source terms made for utilization in the analysis of a severe accident by integrating the results of studies of severe accidents occurred before. The calculation results show the early fatality zero deaths and latent cancer fatality about only 13 deaths in Seoul. Thus, actual impacts of a radiological release will be psychological in terms of downwind perceptions and anxiety on the part of potentially exposed populations. Even considering the simultaneous accident occurrence in both 5-MWe graphite-moderated reactor and 100-MWt light water reactor, the consequence analysis using the MACCS2 code shows no significant damage to people in South Korea.     

Lessons learnt from ITER safety & licensing for DEMO and future nuclear fusion facilities

One of the strong motivations for pursuing the development of fusion energy is its potentially low environmental impact and very good safety performance. But this safety and environmental potential can only be fully realized by careful design choices. For DEMO and other fusion facilities that will require nuclear licensing, S&E objectives and criteria should be set at an early stage and taken into account when choosing basic design options and throughout the design process.Studies in recent decades of the safety of fusion power plant concepts give a useful basis on which to build the S&E approach and to assess the impact of design choices. The experience of licensing ITER is of particular value, even though there are some important differences between ITER and DEMO. The ITER project has developed a safety case, produced a preliminary safety report and had it examined by the French nuclear safety authorities, leading to the licence to construct the facility. The key technical issues that arose during this process are recalled, particularly those that may also have an impact on DEMO safety. These include issues related to postulated accident scenarios, environmental releases during operation, occupational radiation exposure, and radioactive waste.     

放射性废物中等深度处置安全目标研究

随着我国核工业的发展,积累了相当数量的长寿命放射性核素浓度较高的低中放废物,IAEA建议将这些废物进行中等深度处置。为尽快开展中等深度处置的相关研究,调查分析了我国需进行中等深度处置的废物源项,在此基础上,参考国外中等深度处置设施的安全目标,结合我国相关核安全法规标准要求,给出了我国放射性废物中等深度处置设施关闭后长期安全目标为1mSv/a、安全防护时间尺度为1000a以上,其运行期间的安全目标可参考GB 13600中的相关目标值。利用OECD/NEA对核素浓度限值的推导方法,初步计算了钻探情景和钻探后情景主要核素的活度限值。     

Developing Integrated Decommissioning Information Management System (IDIMS) of Nuclear Facilities

In Taiwan, the Taiwan Research Reactor (TRR) was shut down in January 1988, and a few nuclear facilities were accompanied to stop operation within Institute of Nuclear Energy Research (INER). For public health and safety reasons, INER dismantled step by step its expired nuclear facilities. Integrated Decommissioning Information Management System (IDIMS) was developed to ensure safety of dismantling and to record all activity data during the decommissioning project. These recorded activity data range from data of planning, licensing, post-operation to those of radioactive waste management and storage. In addition, IDIMS was expected to preserve decommissioning knowledge using information technology from practical data and problem solving. It also is anticipated that IDIMS will be an important knowledge repository and design base for decommissioning projects of nuclear power plants in Taiwan.     

AP1000核电厂灵活循环燃料管理策略研究及应用

我国核电装机容量逐年稳步扩增,核电厂参与电网调峰愈加频繁,固定的换料周期逐渐难以满足核电厂经济运行的需求。本文基于AP1000核电厂18个月堆芯装载方案,设计了±1个月和±2个月的灵活周期堆芯装载方案,完成方案的安全性限值与燃料经济性评价,开展完整的安全分析。结果表明,堆芯设计满足安全相关验收准则的要求,全面论证了灵活循环燃料管理策略的安全性和可行性。本研究为AP1000核电厂灵活循环周期运行提供了技术支撑,灵活循环周期运行即将在海阳核电厂中工程应用。     

卡利纳循环在核电厂二回路系统的应用探讨

在朗肯循环的基础上,介绍了卡利纳循环的特点和优势,简述了卡利纳循环在国外的发展概况,从理论上重点分析和阐述了卡利纳循环应用于核电厂二回路系统的可行性.结论表明,应用卡利纳循环可以提高核电厂热效率10%以上,并将显著减少循环冷却水系统和回热、再热系统的投资成本.但是,核电厂二回路工质的改变将改变热力系统,将牵涉到整个热力系统设备的重新研究开发.卡利纳循环是否能够应用于核电厂二回路系统还有待进一步的研究探讨.     

A 10 MWe pressurized water reactor for safe and reliable power

A design for an innovative, passively safe 10 MWe power plant based on the proven pressurized water reactor technology has been developed. The plant incorporates an innovative design approach to achieve “walk-away” safety and includes significant simplification and elimination of systems and components when compared to the current generation commercial nuclear power plants. The plant has been designed such that the majority of the equipment will be pre-assembled as modules at off-site facilities and shipped to the site on trucks for installation. This approach will provide shorter construction schedules and improved quality control.     

核燃料循环设施物项安全分级方法研究

简单合理的物项安全分级,不仅可以提高设施的安全性,而且还可以减少审评双方的分歧,降低营运单位和设计单位的工作量。在分析国内外核动力装置采用核安全功能进行物项安全分级和乏燃料后处理设施采用剂量准则开展物项安全分级的基础上,研究提出了采用放射性物质包容量开展核燃料循环设施的物项安全分级的方法,并采用“未缓解释放”的事故分析方法,将放化安全一级(250 mSv)和放化安全二级(5 mSv)对应的剂量准则转化为放射性物质包容量限值。     

Integrated software safety analysis method for digital I&C systems

The digitalized Instrumentation and Control (I&C) system of Nuclear power plants can provide more powerful overall operation capability, and user friendly man-machine interface. The operator can obtain more information through digital I&C system. However, while I&C system being digitalized, three issues are encountered: (1) software common-cause failure, (2) the interaction failure between operator and digital instrumentation and control system interface, and (3) the non-detectability of software failure. These failures might defeat defense echelons, and make the Diversity and Defense-in-Depth (D3) analysis be more difficult. This work developed an integrated methodology to evaluate nuclear power plant safety effect by interactions between operator and digital I&C system, and then propose improvement recommendations. This integrated methodology includes component-level software fault tree, system-level sequence-tree method and nuclear power plant computer simulation analysis. Software fault tree can clarify the software failure structure in digital I&C systems. Sequence-tree method can identify the interaction process and relationship among operator and I&C systems in each D3 echelon in a design basis event. Nuclear power plant computer simulation analysis method can further analyze the available backup facilities and allowable manual action duration for the operator when the digital I&C fail to function. Applying this methodology to evaluate the performance of digital nuclear power plant D3 design, could promote the nuclear power plant operation safety. The operator can then trust the nuclear power plant than before, when operating the highly automatic digital I&C facilities.     

Safety aspects and environmental impact of an inertial confinement fusion reactor

Releases into the environment of radioactive materials contained in heavy ion fusion (HIF) reactor plants must be prevented by similar safety design concepts as they are applied to present fission converter (e.g. LWR's) and breeder reactors (LMFBR's). This study identifies significant safety aspects of inertial confinement fusion power plant concepts and relates them to the more familiar basis of knowledge about the safety and the hazards of other advanced nuclear power reactor systems such as the LMFBR. Assessments of doses to be expected after the release of tritium from HIF reactor plants — normally and accidentally — are performed and compared with dose limits and with doses resulting from facilities of the fission fuel cycle. Needs for safety related research and development specifically for inertial confinement fusion as well as for the modelling of the various exposure pathways due to released tritium are pointed out.     

Some comments on the concept of ‘underground siting of nuclear power plants’ — A critical review of the recently elaborated numerous studies

This paper concerns the comprehensive problems of underground nuclear power plants (UNPP) with regard to increased safety considerations. This constructional concept is not new, but has not yet been realized, for commercial facilities it is again a matter for discussion. Recently numerous studies (especially in the USA and the Federal Republic of Germany) have been elaborated and they come to considerably different conclusions — already concerning partial subdivisions. It is the aim of this contribution to critically analyse these studies, especially with regard to the principal question of different basis design criteria, constructional concepts and impacts as well as problems of licensibility and operation. Due to the size of these analyses and first of all due to the lack of in situ experiences it seems too early to give at this time period final (pro or con) recommendations concerning the undergrounding of nuclear facilities.     

核电厂丧失厂外电的经验反馈

核电厂厂用电系统的功能是为核电厂设施提供安全可靠的电源,核电厂供电安全对核安全至关重要。福岛第一核电厂就是在丧失厂用电及最终热阱的情况下发生了严重的核事故。厂用电系统具备两列相互独立的厂外电源作为工作电源和辅助电源。文章通过收集国内外运行核电厂丧失厂外电事件,对运行核电厂丧失厂外电的机组状态、事件发生原因进行了分析,提出了应对厂外电失效的改进措施和建议。     

Operational analysis of nuclear research facilities in 1999–2008

The actual data on the number, type, operating state, and use of nuclear research facilities are presented. The generalized operational indices of the facilities for 1999–2008 are given; they were obtained on the basis of an analysis of the information entering the sector center for the collection and analysis of safety information concerning nuclear research facilities. Information is presented on the research being conducted at the facilities and the intensity with which the research reactors are used. Attention is focused mainly on the safety of nuclear research facilities. The results of an analysis of disruptions of the operation of the facilities are examined in detail. It is shown that the operation of nuclear research facilities is safe from the nuclear and radiological standpoints.     

核设施退役信息数据库的结构与功能设计

核设施退役工程是一项不仅需要考虑拆除（毁）设备、建筑物,还要考虑辐射影响和核废物处理的复杂工程,其拆除（毁）工作具有高危险、高污染的特点,因此建立针对核设施退役项目的信息系统辅助退役工程很有意义。本文通过收集退役活动数据(设备物资数据、源项数据、辐射剂量数据等)设计退役信息数据库,开发了基于退役数据库的信息管理系统,该系统可对数据库中各类信息数据（照片、图纸、辐射数据、时间等）进行录入、删除、修改、查询等基本操作,并根据各类数据处理流程的特点分功能模块进行相应数据信息的管理,并对不同数据信息进行分析。该系统可提升退役过程中的管理能力,优化工程安排,减少作业人员所受辐射剂量,是顺利进行退役活动的必要基础。