Technical modifications & management innovations in exporting nuclear reactor projects

As a main channel for the foreign economic cooperation of China nuclear industry, China Zhongyuan Engineering Corporation （CZEC） has been constantly engaged in technical modifications and management innovations in its exporting nuclear reactor projects. In the implementation of heavy water research reactor contract in Algeria, CZEC had established a complete and adequate design standards system in compliance with the international standards, and made significant modifications to the reference reactor in the aspects of reactor power and reactor safety, solved quite some technical issues which＇affected the reactor technical performance. The modifications and improvements enabled the tech- nical parameters, safety features, reactor multipurpose application to attain to the advanced level in the world. In the 300 MWe PWR NPPs in Pakistan, safety features had been updated in line with upgrading regulatory requisites. The design philosophy and technology application demonstrated CZEC＇ s creation and innovation on basis of constant safety enhancement of nuclear power projects. Efforts had also been made by CZEC in promoting China made equipment items and components exportation.     

Seismic design and analysis of nuclear power plant structures

The seismic design and analysis of nuclear power plant (NPP) begin with the seismic hazard assessment and design ground motion development for the site. The following steps are needed for the seismic hazard assessment and design ground motion development： a. the development of regional seismo-tectonic model with seismic source areas within 500 km radius centered to the site; b. the development of strong motion prediction equations; c. logic three development for taking into account uncertainties and seismic hazard quantification; d. the development of uniform hazard response spectra for ground motion at the site; e. simulation of acceleration time histories compatible with uniform hazard response spectra. The following phase two in seismic design of NPP structures is the analysis of structural response for the design ground motion. This second phase of the process consists of the following steps： a. development of structural models of the plant buildings; b. development of the soil model underneath the plant buildings for soil-structure interaction response analysis; c. determination of in-structure response spectra for the plant buildings for the equipment response analysis. In the third phase of the seismic design and analysis the equipment is analyzed on the basis of in-structure response spectra. For this purpose the structural models of the mechanical components and piping in the plant are set up. In large 3D-structural models used today the heaviest equipment of the primary coolant circuit is included in the structural model of the reactor building. In the fourth phase the electrical equipment and automation and control equipment are seismically qualified with the aid of the in-structure spectra developed in the phase two using large three-axial shaking tables. For this purpose the smoothed envelope spectra for calculated in-structure spectra are constructed and acceleration time is fitted to these smoothed envelope spectra.     

Project Construction and Important Technical Innovation for Qinshan Phase Ⅲ (PHWR) Nuclear Power Plant

Qinshan Phase Ⅲ (PHWR) Nuclear Power Plant, the first commercial heavy water reactor nuclear power plant in China, was the biggest trade project performed between the governments of China and Canada. As the owner, the Third Qinshan Nuclear Power Company (TQNPC) persisted in independent innovation management during the project construction, commissioning and selfdependent operation, efficiently realizing the three controls of the project, i.e. quality control, schedule control and investment control, and persisted in technical improvement on the basis of digestion and absorption of CANDU6 technology to improve the unit safety and reliability. The project construction practice has helped China’s nuclear power project management to becomeprogrammed, computerized, standardized and internationalized management from the existing basis. After completion of the project, with unit safe and steady operation as the prerequisite, TQNPC performed several technical modifications and innovations to continuously improve the unit performance. In the area of staff development, TQNPC paid much attention to cultivation of corporate culture, strengthed staff training and built up a good circulating mechanism with staff training and project construction promoting each other. Further to “Zero Breakthrough” and a new step forward of locolization successfully realized in Qinshan Nuclear Power Plant and Nuclear Power Qinshan Joint Venture Company, the improvement and developemnt of nuclear power project management level in Qinshan Phase Ⅲ (PHWR) Nuclear Power Plant provided reference for promotion of nuclear power development in China and standardized management of introducing large imported project.     

SCWR for Future LargeScale Nuclear Power Generation

The ambitious nuclear power program motivates the Chinese nuclear community to develop advanced reactor concepts of generation IV, in order to ensure the longterm, stable and sustainable development of nuclear power. The supercritical watercooled reactor (SCWR) has favorable features in economics, sustainability and technology availability. It is the logical extension of the existing PWR technology and has very promising perspectives in largescale power generation in China. This paper describes the main features of SCWR. New designs of SCWR core structure and fuel assemblies are proposed. Preliminary analysis using a coupled neutronphysics/thermalhydraulics method is carried out and shows a good feasibility of the new design proposal.     

The principle of minimization of the equivalent load for design of launching vertical shiplift

Launching vertical shiplift is a type of shiplifts which have the advantages in characteristics of dynamics and statics, safety and simplicity in operation. But their applications are limited as the scales of mechanical equipments are too large. This paper puts forward the principle of minimization of the equivalent load for the general layout design of launching vertical shiplifts, based on the analysis of the load probability of the main hoists and their key mechanical equipments. The principle aims at determining the optimal weight of counterweight so that the equivalent loads of the main hoists of shiplifls are minimized, and larger ships are permitted to pass through. The theory and method presented in this paper have been applied in the design of the first step and third step shiplifts of the Goupitan Hydro Power Station. This has resulted in the breakthrough of the design and manufacture of launching vertical shiplifts so that the ships with tonnage of 500 t can pass through hydro dams for this type of shiplifts, comparing with the largest launching shiplift in Yantan Hydro Power Station with the 250 t shiplift.     

User Driven Innovation in the Building Process

During the late years there has been an ever-increasing focus on the possibilities to change the building process to raise quality on the final building products as well as the activities of actors involved in the building process. One reason for this interest is the new opportunities evolving due to introduction of advanced information and communication technology (ICT). The paper focuses on creative changes of the building process powered by user driven innovation activities. An overview of existing user driven innovation methodologies is given as well experiences from the ongoing Virtual Innovation in Construction (VIC) project. One important driving force for change is the opportunity for users to develop and articulate real needs concerning for example different functionalities of a building and its parts, but also on artifacts supporting the actual needs capture and requirements formulation during building design. A general methodological framework and meta ontology for Virtual Innovation in Construction is presented as well as findings from implementation of the method.     

Development of Finite Element Limiting Analysis Method and Its Applications in Geotechnical Engineering

The Finite Element Limiting Analysis Method (LELAM) has the advantage of combining a numerical analysis method with traditional limiting equilibrium methods. It is particularly applicable to the analysis and design of geotechnical engineering. In the early 20th century,FELAM has been developed vigorously in domestic geotechnical engineering over international common finite element procedures. It has made great achievements in basic theory research and computational precision, thus broadening the application fields in practical projects. In order to gradually make innovations in geotechnical design methods, some of our research results are presented, mainly including geotechnical safety factor definitions, the principles for use of the method concerned, the overall failure criterion, the deduction and selection of the yield criterion, and the measurement to improve the computational precision, etc..The application field has been broadened from twodimensional to threedimensional, from soil slope to jointed rock slope and foundation, from stable seepage to nonstable seepage, from slope and foundation to tunnel. This method has also been used in search of many hidden sliding surfaces of complex landslides, conducting the structural support design considering the interaction between the soil and the structure, and computing simulation foundation bearing plates load tests, etc..     

Severe accident risks from external events

This paper reviews the early development of design requirements for seismic events in US early developing US nuclear electric generating fleet. Notable safety studies, including WASH-1400, Sandia Siting Study, and the NUREG-1150 probabilistic risk study are briefly reviewed in terms of their relevance to extreme accidents arising from seismic and other severe accident initiators. Specific characteristic about the nature of severe accidents in nuclear power plants are reviewed along with present day state of art analysis methodologies (MELCOR and MACCS) that are used to evaluate severe accidents and to optimize mitigative and protective actions against such accidents. I is the aim of this paper to make nuclear operating nations aware of the risks that accompany a much needed energy resource and to identify some of the tools, techniques and landmark safety studies that serve to make the technology more safe and to maintain vigilance and adequate safety culture for the responsible management of this valuable but unforgiving technology.     

The Module HTGR Development in China

High Temperature Gas-cooled Reactors are recognized as a representative advanced nuclear system for the future owing to the excellent safety performance, high efficiency, multipurpose uses and hydrogen production. These type reactors are characterized by ceramic coated particle fuel, inert helium as coolant, and graphite used as moderator and reflector in core, which makes the outlet temperature of coolant reaching 950℃ even more. Under the National High Technology Program, the HTR10 project has been successfully implemented and achieved full power operation in connection with the grid in January of 2003. HTR10, which is the first module HTR with inherent safety feature around world, has carried out safety demonstration tests simulating the severe accident conditions in 2004.Based on the proven technologies and experience feedback during HTR10 design, manufacture, construction and operation, a HTRPM demonstration power plant with 200MWe power capacity sited at Rongcheng of Shandong province has been initiated.     

The Progress of Researches on ADS in China

he conceptual study of the accelerator driven system (ADS) that lasted for about five years ended in 1999 in China. As one project of the National Basic Research Program of China (973 Program) in the energy domain, which is sponsored by the China Ministry of Science and Technology (MOST), a fiveyearprogram of fundamental research of ADS physics and related technology was launched in 2000 and passed national review at the end of 2005. The China Institute of Atomic Energy (CIAE), the Institute of High Energy Physics (IHEP), the Institute of Heavy Ion Physics in Peking University (PKUIHIP) and other institutions jointly carried out the research. The research activities were focused on HPPA physics and technology, reactor physics of external source driven subcritical assembly, nuclear data base and material study. For HPPA, a high current injector consisting of an ECR ion source, LEBT and an RFQ accelerating structure of 3.5 MeV was built. In reactor physics study, a series of neutron multiplication experimental study has been carried out and still being done. The VENUS facility has been constructed as the basic experimental platform for neutronics study in ADS blanket. It’s a zero power subcritical neutron multiplying assembly driven by external neutron produced by a pulsed neutron generator. The theoretical, experimental and simulation study on nuclear data, material properties and nuclear fuel circulation related to ADS is carrying on to provide the database for ADS system analysis. The main results on ADS related researches will be reported.     

A self-adaptive synchronization controller for Liu chaotic systems

A kind of synchronization controller for Liu chaotic systems whose nonlinear components are subject to Lipschitz condition was proposed. By using Lyapunov function and linear matrix inequality technique, a selfadaptive synchronization controller was constructed for Liu chaotic systems. There are two components of our derived synchronization controller: linear and nonlinear component. Linear component is composed of errors of the state variables between drivingsystems and respondingstems, and nonlinear component is a selfadaptive synchronization controller. a proof was given for proving the feasibility of this method, and numerical simulations of Liu chaotic systems show its effectiveness. Furthermore, this method can be applied to other chaotic systems, such as Chen systems, Lorenz systems, Chua systems and Rssler systems,etc.     

Construction Process Simulation and Safety Analysis Based on Building Information Model and 4D Technology

Time-dependent structure analysis theory has been proved to be more accurate and reliable compared to commonly used methods during construction. However, so far applications are limited to partial period and part of the structure because of immeasurable artificial intervention. Based on the building informa-tion model (BIM) and four-dimensional (4D) technology, this paper proposes an improves structure analysis method, which can generate structural geometry, resistance model, and loading conditions automatically by a close interlink of the schedule information, architectural model, and material properties. The method was applied to a safety analysis during a continuous and dynamic simulation of the entire construction process. The results show that the organic combination of the BIM, 4D technology, construction simulation, and safety analysis of time-dependent structures is feasible and practical. This research also lays a foundation for further researches on building lifecycle management by combining architectural design, structure analysis, and construction management.     

Research on plastic fender development and key technologies

Automotive lightweight and safety performance come into play as key technologies to promote competiveness, and average applied amount of automotive plastics has become a significant sign for automotive industrial development level of a country.Various performances of a vehicle with plastic automotive fenders are analyzed in the paper.The research is emphasized on sinking-resistance and pedestrian protection performance of the plastic fenders by studying plastics characteristics and simulation analysis.It offers references for engineering design in which both automotive lightweight and safety performance are achieved and well balanced.     

Development and Application of Maintenance Template in Pressurized Water Reactor Nuclear Power Plant

Good practices of maintenance optimization in nuclear power field need to be effectively consolidated and inherited,and maintenance optimization can provide technology support to create a long-term reliable and economic operation for nuclear power plants( NPPs) especially for a large number of nuclear powers under construction. Based on the development and application of maintenance template in developed countries,and combining with reliability-centered maintenance( RCM) analysis results and maintenance experience data over the past ten years in domestic NPPs, the development process of maintenance template was presented for Chinese pressurized water reactor( PWR) NPP,and the application of maintenance template to maintenance program development and maintenance optimization combined with cases were demonstrated. A shortcut was provided for improving the efficiency of maintenance optimization in domestic PWR NPP,and help to realize a safe,reliable,and economic operation for domestic NPPs.     

Estimation of the Dose Rate of Spent Fuel-Related Components of Lingao Nuclear Power Plant Using ORIGEN2 and MCNP5

The components from spent fuel are discharged from the core and then stored in the framework of the spent fuel pool for cooling. However, it is of great significance to save the storage space of the spent fuel pool by shrinkage and shearing work to increase the spare fuel lattice number. In order to solve the problem of shrinkage and shearing work of spent fuel involving the problem of radioactive safety, the radioactive source item is calculated by ORIGEN2 program base on Unit 1 Ⅱ of Lingao Nuclear Power Plant(NPP), and the radiation dose rate of the related component shrinkage operation scene is simulated by the MCNP5 program. In addition, the effectiveness of shielding measures is discussed, and the maximum dose rate is within 0.35 μSv/h at the distance of 2.5 m from component center, and the maximum dose rate is almost 0 at the distance of 3.2 m from the component center. The intensity of the radiation dose produced by the related components is very low and can be neglected, which belong to the green area of NPP. The program calculation system from source term calculation to shielding calculation is established, and an engineering example is referenced, and its application and analysis are carried out. It provides a basis for radioactive safety analysis and evaluation for the shrinkage operation of spent fuel and makes the shrinkage technology of fuel-related components safer and more reliable.     

Load compensation research on twicetension for loop anchor cable of inner lining in Yellow River-crossing tunnel

The load compensation equipment for anchor cable named low retraction prestressed anchorage system with twice-tension （referred to as twice-tension anchorage system） is proposed in the paper. Calculation results of loop anchorage prestressing loss （PL） values of inner lining （IL）in Yellow River-crossing tunnel under two anchorage systems, including twice-tension anchorage system and HM （Chinese transliteration is huanmao） anchorage system, are introduced. The software ANSYS is selected to realize the three-dimensional （3D） finite element modeling to accomplish simulation and calculation works under the two anchorage systems, respectively. Stress processes of IL under the two working conditions, of which one is completed cable tensioning （CCT） and the other is water in the tunnel with the designed water pressure （DWP）, are contrasted and analyzed. Impacts of prestressing forces of anchor cables on structural safety under the two anchorage systems are contrasted. The calculation results show that the twice-tension anchorage system can reduce PL effectively and then increase prestresses of wall concrete （WC）. Meanwhile, the anchorage system has the advantages of improving security and stability of tunnel structure, reducing project costs and saving steel consumption. The research work is available to related design and construction of anchor cable, and is worthy of promotion and application.     

Trade-offs in Specific CMOS RF Communication Circuits

The design trade-off in the front-end of the transceiver,such as LNA,mixer,local oscillator and PA,is concerned. The advantages and limitations of the circuit topologies and key parameters of the state-of-the-art CMOS transceiver building blocks are discussed in order to gain more insight about a specific block design. A normalized formula of the figures of merit for each building block is also proposed to evaluate the overall performance of various circuits for fair comparison.     

Application of the strength reduction FEM to diversion tunnel plug stability

<正>Firstly,the common design principles for diversion tunnel plug are generalized,and two kinds of numerical analysis methods are discussed.Then the strength reduction FEM is introduced in numerical model analysis and the design steps of the plug's length are illustrated.During the progress to determine the plug's length,the equivalent plastic strain on the potential slip surface is assumed as the flag to tell the failure against sliding,and the plug stability is overall estimated from the plastic zone range and connectivity.     

Fast Reactor Technology Development in China Status and Prospects

China has decided to speedup the nuclear power development. It is programmed that the nuclear power capacity will reach 40 GWe in 2020 and envisaged 60 GWe and 240 GWe in 2030 and 2050 respectively. The basic strategy of PWRFBR matched development with Fast reactor metal fuel closed cycle for a sustainable and quick increasing nuclear energy supply is adopted. Another strategy also decided is that the partitioning and transmutation of MA will be realized using fast burner and ADS.The fast reactor engineering development will be divided into three steps: China Experimental Fast Reactor (CEFR 65 MWt/20 MWe), China Prototype/Demonstration Fast Reactor (CPFR/CDFR ≥ 1 500 MWt/600 MWe) and China Demonstration Fast Breeder Reactor (CDFBR 1 000～1 500 MWe). The CEFR is under installation and preoperation testing with it’s first criticality planned in 2009. The design study of CPFR is just started in 2006. Recently a discussion for the second step is under way to faster the fast reactor development by a larger than 600 MWe CPFR and as a role of CDFR.