[en] 3D-coarse mesh expansion method is used to solve neutron diffusion equation for nuclear reactor core which is composed of hexagonal lattice assembly, and to obtain a nine point high order finite differential equation similar in form to low order finite differential equation. The nine point high order finite differential equation can be solved by using of solving technology problem of low order finite differential equation. The founded method may be applied to 2D or 3D-neutron diffusion calculations for nuclear core design and depletion analysis

[en] A coarse mesh expansion mehtod of reactor fuel management code, CFM3D, including the method, making skill, main specialities and the functions of the code is described. Computing results of some reactor cores by CFM3D are analyzed and are compaired with other codes. The code has been used for designing some reactor cores and analyzing fuel burn-up

[en] FITLINK is one of main programs of NDFMPS, a program system for core nuclear design and fuel management program system, and is a treatment program of cross section parameter of fuel assembly. In this program, effects of burnup level, soluble boron concentration, power density, moderator density and control rods for cross section parameters are considered

[en] Vibrating loading is an important process in the production of nuclear fuel elements, and the automation of loading process has a great influence on the quality of nuclear fuel elements. According to the process characteristics and control requirements of vibrating loading in CJNF Co., Ltd, a vibrating loading process control system based on field bus AS-i has built. The system takes Schneider PLC as the core, and combines the control network of AS-i field bus with Ethernet to form a vibrating loading process control system, which realizes the control of vibrating loading process. The operation results show that the application of AS-i bus technology in fuel rod vibrating loading process improves the level of automation of loading process, solves the disadvantages of complex and uneconomical wiring and time-consuming debugging of traditional PLC control system, highlights the advantages of AS-i bus. It has a typical application and demonstration role. (authors)

[en] Kurganov and Tadmor have developed a numerical scheme for solving the initial value problem for hyperbolic systems of conservation laws. They showed that in the scalar case their scheme satisfies a local maximum-minimum principle i.e., the solution at future is bounded above and below by the solution at current locally. In this paper we show that this scheme is positive in the sense of Friedrichs for systems as well. We present the scheme of Kurganov and Tadmor as a convex combination of composites of positive schemes. Since each component of a composite scheme is bounded in the l² norm, so is the convex combination of the composites. To achieve second order accuracy in time, we use a Runge-Kutta type scheme due to Shu and Osher. We present two numerical experiments to add to the ones carried out by Kurganov and Tadmor

[en] The project feasibility demonstration of the nuclear design for the long cycle reactor core of Qinshan phase II is briefly introduced. The high performance fuel assembly is assumed to be loaded in the core. 1/3 hybrid reload mode and the bearing-Gd burnable poison is adopted in the project recommended. The equilibrium cycle batch discharge burnup and cycle length shall reach 42 GW·d/t(U) and 410EFPD, respectively. The study shows that all the limit criteria are satisfied

[en] The relationship between the content of the burnable poison (Gd) and the main results of the in-core fuel management for the Mega-kW PWR nuclear power plant long cycle core (18 month reload) is analyzed using the advanced fuel management design code package. The fuel assemblies of the various contents of the burnable poison and the various number of the burnable poison rod are calculated, and the infinite multiplication factor versus burnup for different assemblies is given out. Accordingly this, the results of four fuel management schemes are calculated. The results show that the scheme which uses lower content of burnable poison and more poison rods is better than that uses higher content of burnable poison and fewer poison rods

[en] Reactor core nuclear design of Qinshan-II NPP adopts the advanced PWR design ideas that appeared recently. The low linear power density is used in the core design to increase the core safety margin; it gives the reasonable arrangement of different enriched fuel assemblies and burnable poison rods to improve the core physical characteristics; and the core also uses one fourth OUT-IN reload manner to make full use of the fuel. The discharged burnup will reach 35 GW·d/t(U) and satisfy the requirement of annual reload mode. The calculating method and the design codes are advanced and were verified by many strict calculations. From the results of Daya-Bay NPP and Qinshan-II NPP calculated by use of these codes, one can believe that the codes are reliable in Qinshan-II design. The design shows that the core is advanced, safe and economical

[en] Behavior and process of oxidisation of ultra-fine tungsten wire prepared by electrochemical corrosion technology were studied using SEM photography, energy spectrum, XRD and mechanical property test. It was shown that black-brown oxidized products in the air were complex oxidate where oxygen quantivalence was between + 4 and + 6. Mass percent of oxygen in the surface of ultra-fine tungsten wire after electrochemical corrosion had already exceeded 1%. While the tungsten wire was oxidating in air, oxygen content in the surface of tungsten wire first increased and then decreased. Regular strips formed on the surface of W wire after electrochemical corrosion, while 10 months after oxidation, irregular striation appeared, and 85 months after fluctuation of both regular strips and irregular striation tended to be weak. Break-down strength of tungsten wire decreased but ductility changed little after oxidation. Such properties may relate with both protective and un-protective properties of oxidate of W. (authors)

[en] In order to detect the edge of solid motor' CT image much better, a new edge detection operator base on gravitation model was put forward. The edge of CT image is got by the new operator. The superiority turned out by comparing the edge got by ordinary operator. The comparison among operators with different size shows that higher quality CT images need smaller size operator while the lower need the larger. (authors)