The European pressurized water reactor Result of the French–German cooperation of experienced NPP suppliers and operators

In 1989 Framatome and Siemens, the two most experienced European nuclear power plant suppliers, decided to join the efforts for the development of a new reactor type for the next generation in their equally owned subsidiary Nuclear Power International (NPI). In 1992 Electricité de France and the major German utilities operating nuclear power plants merged their own development programs with that of Nuclear Power International and initiated the European Pressurized Water Reactor (EPR) project. In order to reach the two major targets of the project, the licensability in both countries, France and Germany, and the competitiveness of nuclear energy with other alternative energy sources, the design basis which had differently developed in the two countries needed to be harmonized. In parallel, the licensing authorities of both countries extended their existing cooperation in the field of a safety survey of existing nuclear power plants to the definition of safety criteria for the next generation of nuclear power plants. Through this cooperation the licensability of EPR in France and Germany will be assured. Continuously performed cost analysis show in addition that also the second target of the project, the competitiveness with alternative primary energy sources, can be achieved. Thanks to the fruitful cooperation between all parties involved, satisfactory results have been achieved not by a simple superposition of existing design features but through a careful evaluation and combination of the best available alternatives. At the end of 1997 the basic design results were compiled in a final report. Subsequently an optimization phase was launched that further improves the competitiveness of the power generation costs.     

Department of energy’s annealing prototype demonstration projects

One of the challenges utilities face in addressing technical issues associated with the aging of nuclear power plants is the long-term effect of plant operation on reactor pressure vessels. These vessels are exposed to neutrons during the operation of a reactor. For certain plants, this exposure can cause embrittlement of some of the vessel welds, which can shorten the useful life of the vessel. This reactor pressure vessel embrittlement issue has the potential to affect the continued operation of a number of US pressurized water reactor plants. However, the properties that are degraded by long-term irradiation can be recovered through a thermal annealing treatment of the vessel steel. Although a dozen Russian-designed and several US military vessels have been successfully annealed, US utilities concluded that an annealing demonstration using a US reactor pressure vessel was a prerequisite before annealing a licensed US nuclear power plant. In May 1995, the Department of Energy and Sandia National Laboratories initiated a program to evaluate the feasibility of annealing US licensed plants using two different heating technologies. One team completed its annealing prototype demonstration in July 1996, using an indirect gas-fired furnace at the uncompleted Public Service of Indiana’s Marble Hill nuclear power plant in southern Indiana. The second team’s annealing prototype demonstration using a direct heat electrical furnace at the uncompleted Consumers Power Company’s nuclear power plant at Midland, Michigan, was scheduled to be completed in early 1997, but has now been delayed indefinitely. This paper describes the Department of Energy’s annealing prototype demonstration program and the results to date for each project.     

压水堆核电厂气液态放射性流出物源项计算程序CPGale的开发北大核心CSCD

分析了压水堆核电厂运行状态下气液态放射性流出物的产生和排放途径,建立了压水堆核电厂运行状态下气液态放射性流出物源项的计算模型,开发了具有良好人机界面的计算程序CPGale,并采用国内在役压水堆核电厂的流出物源项实测值对程序进行了验证。结果表明,基于CPGale程序计算所得流出物源项相比实测值具有适度的保守性,可满足工程设计的需求。     

European passive plant program: A design for the 21st century

In 1994, a group of European utilities initiated, together with Westinghouse and its industrial partner GENESI (an Italian consortium including ANSALDO and FIAT), a program designated EPP (European Passive Plant) to evaluate Westinghouse passive nuclear plant technology for application in Europe. The following major tasks were accomplished: (1) the impacts of the European utility requirements (EUR) on the Westinghouse nuclear island design were evaluated; and (2) a 1000 MWe passive plant reference design (EP1000) was established which conforms to the EUR and is expected to be licensable in Europe. With respect to safety systems and containment, the reference plant design closely follows that of the Westinghouse simplified pressurized water reactor (SPWR) design, while the AP600 plant design has been taken as the basis for the EP1000 reference design in the auxiliary system design areas. However, the EP1000 design also includes features required to meet the EUR, as well as key European licensing requirements.     

Experience with piping in German NPPs with respect to ageing-related aspects

Thirteen nuclear power plants (NPPs) with pressurized water reactors (PWRs) and six plants with boiling water reactors (BWRs) are currently in operation in Germany. For almost 25 years, GRS has been systematically evaluating the operating experience of these plants. In this paper, the operating experience relating to piping damage in safety-relevant systems of German plants with light water reactors (LWRs) is evaluated with respect to ageing-related effects. The experience with actions taken against piping degradation is illustrated by examples. The results of the evaluation confirm the conservativeness of the safety concept chosen for the design of German NPPs with LWRs, as well as the effectiveness of ageing management.     

The erection and commissioning of the Mülheim-Kärlich Nuclear Power Plant

The contract for the Mülheim-Kärlich Nuclear Power Plant, equipped with a 1300 MWe pressurized water reactor, was awarded in 1973. The erection phase of the plant had been characterized in the mid-seventies by an aggravation of circumstances in connection with the nuclear energy controversy in the Federal Republic of Germany, the tightening of stipulations regarding safety philosophy, regulations and documentation, and by the consequences of the TMI accident in 1979. These led to considerable additional difficulties and delays. The commissioning phase on the other hand proceeded smoothly and speedily without major disturbances. The Mülheim-Kärlich Nuclear Power Plant has some major technical features distinguishing it from other pressurized water reactor plants built in the Federal Republic of Germany. Its nuclear steam system is based on a license from the Babcock & Wilcox Company, USA, but it was adapted to German rules and regulations. The Mülheim-Kärlich power plant is the first of this type and size built and put into operation. Its main technical features are described and, after a brief survey of the erection phase, the results of the start-up operations are discussed.     

浅谈我国核电厂重要厂用水系统换热器隔离阀门与放射性监测仪表配置优化

对于运行核电厂来说,重要厂用水系统与质量和安全密切相关.核电厂重要厂用水系统用于导出设备冷却水系统所传输的热量,将其输送到海水中,因此是核岛的最终热阱.本文描述了当前我国大部分核电厂重要厂用水系统换热器隔离阀门与放射性监测仪表的配置现状,分析了包括美国、法国以及国际原子能机构对于重要厂用水系统设计要求的相同点与不同点,...     

Safety of future reactors in France

This document describes current thinking within the Institute for Protection and Nuclear Safety (IPSN) regarding developments desirable from the viewpoint of safety in a new generation of nuclear power plants, the construction of which could begin in France at the end of the nineties. Significant improvements must be sought, particularly as regards the containment, including the core meltdown case. The operating organization, Electricité de France (EDF), is now considering establishing the basis of a project of European dimension (European Pressurized water Reactor - EPR), in connection with German utilities and the Franco-German vendor Nuclear Power International (NPI); the first options important for safety are to be presented and discussed from September-1993.     

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.     

浮动核电站设计中的安全准则研究

浮动核电站作为船海工程与核电工程的结合,属于核能工程的新领域,国内尚缺少相应的安全设计准则。结合海洋核动力平台示范工程实际设计需求,基于对陆上压水堆核电厂、海上移动式平台、核动力舰船规范的分析,从浮动核电站总体设计、平台设计以及核安全3个层面分别提出了相应的安全设计准则。研究表明,浮动核电站的安全设计应围绕3项基本安全功能进行;平台设计应考虑布置、结构、辅助系统、电力、通信、消防6个因素;核安全设计应充分考虑其孤岛运行和海洋应用场景对核动力装置系统设备设计、运行的制约影响。      

Operating experience with an on-line vibration control system for PWR main coolant pumps

The main circulation pumps are key components of nuclear power plants with pressurized water reactors (PWRs), because the availability of the main circulation pumps has a direct influence on the availability and electrical output of the entire plant. The on-line automatic vibration control system ASMAS was developed for early failure detection during the normal operation of the main circulation pumps in order to avoid unexpected outages and to establish the possibility of preventive maintenance of the pumps. This system is permanently and successfully operating in three German 1300 MW_el NPP's with PWR and has been successfully tested in a 350 MW_el NPP with a PWR.     

核电厂二级PSA释放类划分及代表性事故序列选取研究

国内AP1000、EPR、华龙一号等核电工程项目已将二级概率安全分析（PSA）源项用于应急输入,但二级PSA释放类的划分以及各释放类代表性事故序列的选取尚无明确可操作的方法,需要进一步开展研究。对比研究国内先进核电厂二级PSA释放类划分和代表性事故序列选取情况,以国内某三代先进压水堆核电厂为例,在同一释放类中根据频率和后果选取4个不同的严重事故序列开展源项计算。结果表明,同一释放类4个不同事故序列的源项结果差别较大,建议释放类划分以应用为导向,根据分析目的进行迭代,对同一释放类应选取多个事故序列进行对比分析,以论证释放类划分的合理性和事故序列的代表性。      

Evaluation of piping damage in German nuclear power plants

Information relating to piping damage in safety-relevant systems in German nuclear power plants with light water reactors (both pressurized water reactors (PWRs) and boiling water reactors (BWRs)) were analyzed with respect to the modes and the causes of damages. In general, the total range of observed piping damage is low. The incidents (82) in plants with PWRs affected mainly pipes with small diameters. Almost all damaged piping showed wall-penetrating cracks combined with leakages, which revealed the damage. Initial cracks at piping with larger diameters were discovered in isolated cases during in-service inspections. With regard to the incidents (71) in plants with BWRs, piping with small as well as large diameters was affected to different degrees. Wall-penetrating cracks combined with leakages were detected at piping with small diameters. For large-diameters pipes, cracks were indicated during in-service inspections and supplementary examinations. The results of the incident evaluations confirm the conservativeness of the safety concept chosen for the design of German nuclear power plants with light water reactors.     

压水堆核电站废液处理系统的比较

本文从源项、系统主要处理流程及装置和处理结果三方面对AP1000、EPR和CPR1000三种压水堆核电机组的废液处理系统进行比较,分析了废液处理系统工艺流程及装置的改进和发展趋势。     

Unitized concept for earthquake-resistant nuclear power plants

This paper discusses a unitized concept for an earthquake-resistant nuclear power plant which can withstand major earthquake shaking and fault slips without releasing radioactive material into the atmosphere. A 1000 MWe pressurized water reactor power plant of recent design is adapted to a unitized concept, and cost studies are made for the incremental cost.     

Water chemistry technology – one of the key technologies for safe and reliable nuclear power plant operation

Water chemistry control is one of the key technologies to establish safe and reliable operation of nuclear power plants. Continuous and collaborative efforts of plant manufacturers and plant operator utilities have been focused on optimal water chemistry control, for which, a trio of requirements for water chemistry should be simultaneously satisfied: (1) better reliability of reactor structures and fuel rods; (2) lower occupational exposure and (3) fewer radwaste sources. Various groups in academia have carried out basic research to support the technical bases of water chemistry in plants. The Research Committee on Water Chemistry of the Atomic Energy Society of Japan (AESJ), which has now been reorganized as the Division of Water Chemistry (DWC) of AESJ, has played important roles to promote improvements in water chemistry control, to share knowledge about and experiences with water chemistry control among plant operators and manufacturers and to establish common technological bases for plant water chemistry and then to transfer them to the next generation of plant workers engaged in water chemistry. Furthermore, the DWC has tried and succeeded arranging R&D proposals for further improvement in water chemistry control through roadmap planning. In the paper, major achievements in plant technologies and in basic research studies of water chemistry in Japan are reviewed. The contributions of the DWC to the long-term safe management of the damaged reactors at the Fukushima Daiichi Nuclear Power Plant until their decommissioning are introduced.     

“华龙一号”反应堆堆芯与安全设计研究

“华龙一号”是我国自主设计研发的具有完整知识产权的第三代百万千瓦级压水堆核电技术。本文介绍了“华龙一号”的产生历程，系统论述了“华龙一号”反应堆堆芯与安全设计特点，包括“华龙一号”研发过程中开展的堆芯核设计、热工水力设计、安全设计、设计验证及“华龙一号”持续开展的设计改进与优化等内容，通过采用新的设计理念和设计技术，全面提高了“华龙一号”作为三代核电技术的经济性、灵活性和安全性。      

压水堆核电厂换料物理启动试验优化研究和应用实践

核电厂设计和运行相关核安全法规、导则要求核电厂换料后必须进行物理启动试验。随着堆芯换料设计日趋成熟,试验程序和试验方法得到充分检验。为提升运行经济性,各核电厂设计和运行人员不同程度地开展了换料后物理启动试验优化的研究与实施。本文基于压水堆核电厂监管要求和核电厂运行要求分析,针对物理启动试验优化提出了定性评价、物理分析和试验验证的系统性论证方法,并以秦山核电厂320 MWe机组为例,进行了完善的研究与可行性论证。实施物理启动试验优化后,核电厂换料大修时间大幅缩短,相比以往可提前约2天进入满功率运行,显著提高了核电厂运行负荷因子,提升了运行经济性。     

How the European Pressurised Water Reactor fulfils the utility requirements

The European Pressurised Water Reactor (EPR) is a project pursued by Electricité de France and the major German utilities (RWEE, PreussenElektra, BAG et al.) on the utility side and SIEMENS, Framatome and their common subsidiary NPI on the designer side. In this project, the experience gained through the design, the erection, the commissioning and the operation of the existing PWR in France and Germany are combined and the existing technical solutions were carefully compared and checked before integration into the EPR. The deep involvement of the future operators since the beginning of the project has the objective of optimising the operational behaviour and making maintenance as easy as possible.     

Status of the construction of the THTR-300 MW and the design of a 500 MW follow-on plant

The further completion of the THTR-300 MW_c prototype nuclear power plant will be performed by a consortium of the companies BBC/HRB/Nukem within the planned time schedule: The start of the nuclear commissioning began at the end of August 1983 by loading the first spherical fuel elements into the core. First critically was reached in September 1983. Handover of the plant is scheduled for October 1985 after a 10 months period of test power operation.For the HTR-500 MW_c, which is under discussion as the THTR-follow-on plant, a conceptual design analysis was performed by BBC/HRB on the basis of a private business contract placed by the Arbeitsgemeinschaft Hochtemperaturreaktor (AHR) uniting 16 power industry companies. The HTR-500 is the consequent continuation of the THTR concept. The use of HTR-specific safety characteristics as well as a further optimization of component structures and circuits result in almost the same electricity generation costs with substantially lower absolute capital costs as compared to large pressurized power reactors.