Nuclear Power Institute of China
Nuclear Power Institute of China
Wang Y.,Nuclear Power Institute of China
Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams | Year: 2017
By the linearization method, the mathematic model of point reactor can be simplified. The simplified point reactor model could be further converted to the transfer function with the Laplace transfer tool. Until now, the point reactor transfer function is still used as the basic means for researching the nuclear reactor control system and the relative engineering items. However, through the analysis, it is found that the linearizd point reactor model based on the hypothesis that reactivity is zero when reactor is at the stable state has its own problems. This paper gives the concise analysis of the problems. The analysis method is the combination of theory and experiment. Theoretically, the focus is to compare the time domain results and the frequency domain results by means of the system dynamics principles. Experimentally, based on the engineering parameters, the focus is to compare the time domain computer simulation results and the frequency domain computer simulation results. Through the comparison analysis, the problems are exposed clearly. The paper gives the model modification access for the problems accordingly. © 2017, Editorial Office of High Power Laser and Particle Beams. All right reserved.
Nuclear Power Institute of China and China General Nuclear Power Group | Date: 2014-01-13
A nuclear power plant containment cooling system and a spray flow control method therefor. The system comprises a cooling system liquid tank (2) for storing cooling liquid, wherein the cooling system liquid tank (2) is provided at the top of a containment (1) and the cooling liquid is used for cooling the containment (1) through the gravity of the cooling liquid itself in the situation of an accident, and the cooling liquid is partially evaporated. The nuclear power plant containment cooling system further comprises an adjustment mechanism; wherein the adjustment mechanism is provided at a liquid outlet of the cooling system liquid tank (2), and the adjustment mechanism is used for controlling the flow at the liquid outlet according to buoyancy generated by a liquid level of the collected cooling liquid which is not evaporated.
News Article | January 18, 2016
The big news is that two Chinese state owned nuclear firms have announced plans to build floating nuclear power plants in the 100-300 MW range. (WNA) A demonstration floating nuclear power plant based on China National Nuclear Corporation’s (CNNC’s) ACP100S small reactor will be built by 2019. The move comes just days after China General Nuclear (CGN) said it will build a prototype offshore plant by 2020. CGN announced (next story) on 12 January that development of its ACPR50S reactor design had recently been approved by China’s National Development and Reform Commission (NDRC) as part of the 13th Five-Year Plan for innovative energy technologies. CNNC said that its ACP100S reactor – a marine version of its ACP100 small modular reactor (SMR) design – had also been approved by the NDRC as part of the same plan. CNNC said its Nuclear Power Institute of China subsidiary had completed a preliminary design for a floating nuclear power plant featuring the ACP100S reactor as well as “all the scientific research work.” Construction of a demonstration unit is to start by the end of this year, with completion set for 2019. (WNA) China General Nuclear (CGN) expects to complete construction of a demonstration small modular offshore multi-purpose reactor by 2020. CGN said development of its ACPR50S reactor design had recently been approved by China’s National Development and Reform Commission as part of the 13th Five-Year Plan for innovative energy technologies. The company said it is currently carrying out preliminary design work for a demonstration ACPR50S project. Construction of the first floating reactor is expected to start next year with electricity generation to begin in 2020. The 60 MWe reactor has been developed for the supply of electricity, heat and desalination and could be used on islands or in coastal areas, or for offshore oil and gas exploration, according to CGN. The Chinese company said it is also working on the ACPR100 small reactor for use on land. This reactor will have an output of some 450 MWt (140 MWe) and would be suitable for providing power to large-scale industrial parks or to remote mountainous areas. CGN said the development of small-scale offshore and onshore nuclear power reactors will complement its large-scale plants and provide more diverse energy options. (WNA) A US House of Representatives committee has approved a bipartisan bill to support federal research and development (R&D) and stimulate private investment in advanced nuclear reactor technologies. The Committee on Science, Space, and Technology approved the Nuclear Energy Innovation Capabilities Act. The bill was introduced by energy subcommittee chairman Randy Weber (R-Texas), along with full committee ranking member Eddie Bernice Johnson (D-Texas) and chairman Lamar Smith (R-Texas). The legislation directs the Department of Energy (DOE) to set priorities for federal R&D infrastructure that will enable the private sector to invest in advanced reactor technologies and provide a clear path forward to attract private investment for prototype development at DOE laboratories. It enables the private sector to partner with national laboratories for the purpose of developing novel reactor concepts, leverages DOE’s supercomputing infrastructure to accelerate nuclear energy R&D, and provides statutory direction for a DOE reactor-based fast neutron source that will operate as an open-access user facility. It also authorizes DOE to enable the private sector to construct and operate privately-funded reactor prototypes at DOE sites. In addition, the bill requires DOE to present a transparent, strategic, ten-year plan for prioritizing nuclear R&D programs. (NucNet) The global nuclear security system still has “major gaps” that prevent it from being truly comprehensive and effective, the Washington-based Nuclear Threat Initiative says in its 2016 Index. The index, which assesses nuclear materials security conditions in 24 countries with one kilogramme or more of weapons-usable nuclear materials, says there is no common set of international standards and best practices, there is no mechanism for holding states with lax security accountable, and the legal foundation for securing nuclear materials is neither complete nor universally observed. In addition to assessing the risks posed by vulnerable nuclear materials and insufficient security policies in states that don’t have materials, the index assesses for the first time the potential risks to nuclear facilities posed by sabotage and cyberattack. It says cyberattacks are increasing and a growing number of states are exploring nuclear energy even though they lack the legal, regulatory, and security frameworks to ensure that their facilities are secure as well as safe. (NucNet) Westinghouse Electric Company’s Springfields facility in the UK has reached the requirements necessary to manufacture Westinghouse small modular reactor (SMR) fuel, Westinghouse said. This milestone is “a key first” for the UK’s SMR programme and an important part of Westinghouse’s proposed partnership with the UK government to deploy SMR technology. Westinghouse Springfields achieved the milestone following a readiness assessment based upon fabrication data for two proprietary SMR fuel assemblies manufactured at the company’s Columbia fuel fabrication facility in the US state of South Carolina. Mick Gornall, managing director of Westinghouse Springfields, said manufacturing Westinghouse SMR fuel at Springfields will “secure the future of a strategic national asset” of nuclear fuel manufacturing capability. (WNA) The first of four reactor coolant pumps for the initial AP1000 unit at the Haiyang site in China’s Shandong province has been transported by road from Curtiss-Wright’s manufacturing facility in Cheswick, Pennsylvania, to the port of Philadelphia ahead of shipment to China, State Nuclear Power Technology Corporation announced yesterday. The first two such pumps for Sanmen 1 in Zhejiang province – expected in September to be the first AP1000 to start up – arrived on the site on 30 December. (NucNet) Testing of the instrumentation and control (I&C) systems has begun at Teollisuuden Voima’s (TVO) Olkiluoto-3 nuclear plant with an application for an operating licence likely to be submitted in April, TVO said. The I&C systems will be used for operating, monitoring and controlling the 1,600-MW EPR unit. In December 2015 TVO said system commissioning of the plant is expected to begin in the spring of 2016 with regular electricity generation beginning in “more than three years. TVO said the estimated schedule came from plant supplier Areva-Siemens. Commissioning of the plant is about nine years behind schedule and costs are almost three times over budget. Market Reform Essential For Nuclear In US, Says NEI (NucNet) Market reform is essential to ensure that the reliability, environmental and economic benefits of nuclear power are not taken for granted, and that reactor operators are compensated for these attributes in the same way as other low-carbon sources, Alex Flint, the Washington-based Nuclear Energy Institute’s senior vice-president for governmental affairs, said in an interview published on the NEI’s website. Mr Flint said there has been “movement to address the issue”. He said at the national level, the NEI is working with the Edison Electric Institute and the Electric Power Supply Association to make officials at the Federal Energy Regulatory Commission (FERC), the US Department of Energy and the US Environmental Protection Agency aware of the potential challenges to grid reliability and the administration’s clean air goals. In 2015, FERC and a number of regional transmission organizations took significant steps to address flaws in electricity markets that fail to provide the price signals needed to support investment in new or existing nuclear power plants. Mr Flint said, “Urged on by the NEI and a number of energy associations, FERC has begun a rulemaking to address price suppression and promises to address other issues in future. In an encouraging sign, Exelon Corporation cited positive regional reforms in deferring decisions on the potential closing of its Clinton nuclear station in Illinois and the Ginna nuclear station in New York.” Late last year Entergy Corporation said it would close its Pilgrim-1 and Fitzpatrick reactors because of poor economic conditions for nuclear.
Xiao F.,Nuclear Power Institute of China
Yuanzineng Kexue Jishu/Atomic Energy Science and Technology | Year: 2017
With the first order neutron multi-group transport equation discretized using the discrete ordinates solution (SN), a calculation model was established by using finite element method (FEM) based on single element and sweep method based on unstructured meshes. In a preset triangular element, the flux was discretized using Galerkin variation, and a linear system of equations was obtained. The angular flux of the nodes in the triangle element can be got by solving the linear system of equations, with offering some conditions. With the sweep method, all triangular elements will be swept and the differential equation can be solved. Based on the above theoretical model, the program FEGT was encoded. In order to validate this program, a series of examples were calculated. The results show that FEGT code meets the precision requirement. © 2017, Editorial Board of Atomic Energy Science and Technology. All right reserved.
Wen Q.L.,Shanghai JiaoTong University |
Wen Q.L.,Nuclear Power Institute of China |
Gu H.Y.,Shanghai JiaoTong University
Annals of Nuclear Energy | Year: 2010
In this study, a numerical investigation of heat transfer deterioration (HTD) in supercritical water flowing through vertical tube is performed by using six low-Reynolds number turbulence models. All low-Reynolds models can be extended to reproduce the effect of buoyancy force on heat transfer and show the occurrence of localized HTD. However, most k- models seriously over-predict the deterioration and do not reproduce the subsequent recovery of heat transfer. The V2F and SST models perform better than other models in predicting the onset of deterioration due to strong buoyancy force. The SST model is able to quantitatively reproduce the two heat transfer deterioration phenomena with low mass flux which have been found in the present study. © 2010 Elsevier Ltd. All rights reserved.
Yu D.,Tianjin University |
Chen G.,Tianjin University |
Yu W.,Nuclear Power Institute of China |
Li D.,Guangdong University of Petrochemical Technology |
Chen X.,Tianjin University
International Journal of Plasticity | Year: 2012
Experimental results of monotonic uniaxial tensile tests at different strain rates and the reversed strain cycling test showed the characteristics of rate-dependence and cyclic hardening of Z2CND18.12N austenitic stainless steel at room temperature, respectively. Based on the Ohno-Wang kinematic hardening rule, a visco-plastic constitutive model incorporated with isotropic hardening was developed to describe the uniaxial ratcheting behavior of Z2CND18.12N steel under various stress-controlled loading conditions. Predicted results of the developed model agreed better with experimental results when the ratcheting strain level became higher, but the developed model overestimated the ratcheting deformation in other cases. A modified model was proposed to improve the prediction accuracy. In the modified model, the parameter mi of the Ohno-Wang kinematic hardening rule was developed to evolve with the accumulated plastic strain. Simulation results of the modified model proved much better agreement with experiments. © 2011 Elsevier Ltd. All rights reserved.
Wang H.,Nuclear Power Institute of China |
Yin C.,Nuclear Power Institute of China |
Liu J.,Nuclear Power Institute of China
Journal of Alloys and Compounds | Year: 2013
This paper discusses the preparation of titanium-doped UO2 microsphere by the method of sol-gel, its microstructure, pore distribution, grain sizes, and the titanium element distribution through metallographic microscope, scanning electron microscope (SEM) and energy diffraction spectrum (EDS) as well as its density with water immersion method. The experimental results show that at a certain sintering temperature, the adding of a small amount of titanium can obviously improve the sintering performance. In the experimental conditions, the optimum amount of doped titanium is under 0.3% (mass fraction) and the sintering temperature is 1250-1350 C. After the study on the activated sintering mechanism, it is proved that the material transfer mechanism may be the joint action of strengthening cation diffusion and residual oxygen. With regard to the titanium element distribution, in addition to the solid solution of some on the outside of UO2 microspheres, the other titanium oxides gather in the grain boundary in the form of free phase particles. © 2013 Elsevier B.V. All rights reserved.
Xiao H.,Nuclear Power Institute of China
Progress in Nuclear Energy | Year: 2016
An understanding of the behavior of fission gas in uranium dioxide (UO2) fuel is necessary for the prediction of the performance of fuel rods under irradiation. A mechanistic model for matrix swelling by the fission gas in LWR UO2 fuel is presented. The model takes into account intragranular and intergranular fission gas bubbles behavior as a function of irradiation time, temperature, fission rate and burn-up. The intragranular bubbles are assumed to be nucleated along the track of fission fragments, which play the dual role of creator and destroyer of intragranular bubbles. The intergranular bubble nuclei is produced until such time that a gas atom is more likely to be captured by an existing nucleus than to meet another gas atom and form a new nucleus. The capability of this model was validated by a comparison with the measured data of fission gas behavior such as intragranular bubble size, bubble density and total fuel swelling. It was found that the calculated intragranular bubble size and density are in reasonable agreement with the measured results in a broad range of average fuel burn-ups 6-83 GW d/tU. Especially, the model correctly predicts the fuel swelling up to a burn-up of about 70 GW d/tU. © 2016 Elsevier Ltd. All Rights Reserved.. All Rights Reserved.
Zong P.,Nuclear Power Institute of China |
Gou J.,Nuclear Power Institute of China
Journal of Molecular Liquids | Year: 2014
Magnetic multiwalled carbon nanotube/iron oxide composite (Fe 3O4/MWCNT) was synthesized as an adsorbent for the preconcentration of U(VI) from aqueous solutions. The surface properties of Fe3O4/MWCNT were characterized via adopting FTIR, SEM and potentiometric acid-base titration. The sorption behaviors of U(VI) on the surface of Fe3O4/MWCNT were investigated under environmental conditions by using batch technique, such as pH, ionic strength and contact time. The pH-dependent U(VI) sorption behavior on Fe 3O4/MWCNT illustrated that sorption mechanism of U(VI) was achieved by outer-sphere surface complexation at low pH values, while the sorption of U(VI) was achieved by inner-sphere surface complexation and simultaneous precipitation at high pH values. Besides, the pH-dependent sorption also demonstrated an optimal and feasible pH value of 7.0 by adopting Fe 3O4/MWCNT in the preconcentration of U(VI) from aqueous solutions. The sorption kinetic experimental data could be well simulated by using the pseudo-second-order pattern. The Langmuir and Freundlich patterns were employed to simulate sorption isotherms of U(VI) at three different temperatures, the experimental results demonstrated that sorption process was favorable at higher environmental temperature. The maximum sorption capacity of U(VI) on Fe3O4/MWCNT was higher than that of major materials reported. Related experimental data further indicated that Fe 3O4/MWCNT had satisfactory treatment performance for the simulated wastewater. The Fe3O4/MWCNT particles having strong magnetism could be favorably and easily separated from aqueous solution under an external magnetic field. The correlative experimental results further demonstrated that the Fe3O4/MWCNT composite could be a promising adsorbent for the preconcentration of radionuclides from large volumes of aqueous solution. © 2014 Elsevier B.V.
Yu D.,Tianjin University |
Chen X.,Tianjin University |
Yu W.,Nuclear Power Institute of China |
Chen G.,Tianjin University
International Journal of Plasticity | Year: 2012
Monotonic tension, isothermal/anisothermal fully reversed strain cycling and zero-to-tension cyclic tests were conducted within the temperature domain from room temperature to 823 Kto investigate the mechanical behavior of Z2CND18.12N austenitic stainless steel under various uniaxial loading conditions. Interesting results were observed from these tests, including obvious rate-dependence at room temperature but lack of rate-dependence at elevated temperatures with the occurrence of serrated flow stress in tensile tests, more cyclic hardening at higher temperature in strain cycling tests, and tendency to reach shakedown condition at elevated temperatures in zero-to-tension cyclic tests. Dynamic strain aging (DSA) effect was presumably believed to contribute to these characteristics of the material. A thermo-viscoplastic constitutive model was proposed to describe the mechanical behavior of the material under uniaxial loading conditions at small strains. Kinematic hardening rule with two components of back stress and isotropic hardening rule incorporating DSA effect are the novel features of the proposed model. The simulated and predicted results show reasonable agreement with the experimental data. © 2012 Elsevier Ltd. All rights reserved.