No abstract available

No abstract available

[en] A engineering method was developed to estimate the pressure imposed on the wall and the cover of the main vessel of China Experiment Fast Reactor (CEFR) caused by the sloshing of the free surface excited by 3 sine waves. Results from this research have provided important loadings for the stress analysis of the main vessel as well as the internals

[en] During the past 30 years, economy of China has being grown strongly. Even in the year 2009, when the world was hit by the financial crisis, China still kept the 8.7% growth rate. GDP of China has reached 4222G USD. This figure makes China to become the third economic giant in the world. All of the world are focusing on the high-speed development of economy in China; meanwhile they also pay much attention on the energy consumption in China. In addition, as one of the policy to keep the stable supply of the energy and to cut off the drain of CO₂, China now are building more and more nuclear power stations. Many developed countries are very interested in the big market. Some have already joined in the construction of nuclear power stations in China, while some may concern about the supply of the nuclear fuel, as well as nuclear safety in China. The present paper will give a close-up view on China status of the energy, especially the nuclear power industry. It is expected that the international community could have deeper and more complete understanding on the nuclear industry in China, moreover cooperate with China to improve the peace and safe utilization of nuclear energy for the sustainable development of the world. (author)

[en] China, as a developing country with a great number of population and relatively less energy resources, reasonably emphasizes the nuclear energy utilization development. For the long term sustainable energy supply, nuclear application the basic strategy of PWR-FBR-Fusion has been settled and envisaged. Due to the economy and experience reasons the nuclear power and technology development with a moderate style are kept in China up to now. In China mainland apart from five NPPs with 7 units and the total capacity of 5.4 GWe in operation, three NPPs with 4 units are under construction and two NPPs are planned for the Tenth Five Year Plan(2001-2005). Also another one or two NPPs are still in discussion. It could be foreseen that the total nuclear power capacity will reach 8.7GWe before the year 2005 and 14-15 GWe before 2010 respectively. As the first step for the Chinese fast reactor engineering development, the 65MWt China Experimental Fast Reactor (CEFR) is under construction. The main components of primary, secondary and tertiary circuits and of fuel handling system have been ordered. The construction of reactor building with about 40,000m² floor surface has been completed. 127 components have been installed. It is planned that the first criticality of the CEFR will be in the end of 2005. The second step of the Chinese fast reactor engineering development is a 300MWe Prototype Fast Breeder Reactor which is only under consideration up to now. Some important technical selections have been settled, but its design has not yet started. (author)

[en] Highlights: • The axial spatially flux is defined as four order polynomial expansion. • A Diagonally Implicit Runge-Kutta method is adopted. • A flux weighting method is adopted to calculate homogenized cross sections. - Abstract: A nodal neutron kinetics model with a higher-accuracy algorithm for three-dimensional multi-group neutron diffusion calculation is developed for transient analysis of reactor core in hexagonal-z geometry. The spatial discretization technique is based on a high order nodal expansion method for hexagonal-z geometry. In this method, one dimensional radial and axial spatially flux of each node and energy group are defined as quadratic polynomial expansion and four order polynomial expansion respectively. The partially-integrated radial and axial leakages are both approximated by the quadratic polynomial. The time discretization technique is based on a fully implicit scheme combined with a Runge-Kutta method for solving the neutron flux and delayed neutron precursor equations. A flux weighting method is adopted to calculate homogenized multi-group cross sections for transient analysis of control rod ejection accident. The described numerical methods are implemented into the computer code HNHEXK. This code is tested with one static benchmark problem and several kinetic benchmark problems. The numerical results show that the current method has a good agreement with the reference.

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[en] Highlights: • The FSI phenomenon of a scaled elevated tank was studied in a shaking table test. • Equivalent mechanical models, finite element models and experiment were compared. • Transient sloshing and structural response of AP1000 shield building were studied. • The maximum von Mises stresses were found to occur at the corner of air inlet. - Abstract: AP1000 passive containment cooling system water storage tank (PCCWST) is set at the top of a shield building. Its function is to hold the water which will flow by gravity to help cool the containment vessel in the highly unlikely event of an emergency – one of the AP1000 plant’s innovative passive safety systems. The huge amount of water may pose a threat to the integrity of the shield building during an earthquake. In this paper, both modal characteristics and transient response of a scaled elevated water tank model were studied by a shaking table experiment. The acceleration of the supporting structure and displacement of water sloshing were recorded under transient loading. Four numerical models were built, including two-mass equivalent model, single lumped-mass model, and finite element models using Fluid30 and Fluid80 elements. The advantages and disadvantages of different numerical methods were discussed. Moreover, finite element (FE) models of AP1000 shield building were established considering the fluid–structure interaction (FSI) effect. The sloshing phenomenon in PCCWST under resonant three-cycle sine (RTCS) wave and seismic loading was studied. The response of shield building under seismic loading was also studied. The results showed that the maximum von Mises stress occurred at the corner of the air inlet. The shaking table experiment can provide a benchmark for seismic response of an elevated water tank. The FE model of shield building may help improve the design of the AP1000 and CAP1400 in the future

[en] A kinetics model should be constructed to study the hydrogen behavior in the severe accidents for the pressurized water reactor(PWR). The reaction mechanisms and the release rate of hydrogen are the bases of kinetics model. The quantum chemistry software Gaussian03 was used to study the reaction mechanism of zirconium-water based on the HF/3-21G theory model of quantum chemistry. The reaction rate constants were also calculated. The results show that the reaction of zirconium-water is an overall reaction, which is divided into four elementary reactions. The reaction rate of the overall reaction was determined by the second elementary reaction due to its slowest reaction rate constant. It is concluded that the second elementary reaction should be the key elementary reaction to reduce the hydrogen generation. The conservative results reveal that it is safety to study the hydrogen behavior in the severe accidents for PWR using the kinetics model constructed in this presented method. (authors)

[en] Presently in the mainland of China there are 9 units of reactors in five NPPs with the total capacity of 6.7 GWe in operation; 2 units in one NPP are under construction and two NPPs are planned for the Tenth Five-year Plan (2001-2005). Also another one or two NPPs are still in discussion. It could be foreseen that the total nuclear power capacity will reach 8.7GWe before the year 2005, 14-15 GWe before 2010 and nearly 36 GWe before 2020 respectively. The 65MWt China Experimental Fast Reactor (CEFR) is under construction. Presently 90% of the concrete constructions including the main building have been completed. The steel liner and the ventilation pipes are being installed. About 95% detail design and almost all the safety-related design demonstration tests have been carried out. The large-size components including rotating plugs, reactor main vessel, internal structure and diagrid plenum made in domestic factories are under fabrication. Some key components such as CRDM, in-vessel fuel handling machines and sodium valves imported from foreign companies have been delivered to the site. The pre-operation testing program, physics startup program and final safety analysis report are all under preparation. 28 operators including 4 senior operators are accepting training. Due to the delay of the delivery of the reactor main vessel, the first criticality is postponed to the end of 2007 from the end of 2005. The 600MWe China Prototype Fast Reactor (CPFR) has being considered. A relative proposal has been considered to submit to the government