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Nodal expansion method based reduced-order model for control rod movement
Annals of Nuclear EnergyYahui Wang, Honghang Chi, Yu Ma
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A nodal expansion method for fast reactor calculations in hexagonal geometry
Annals of Nuclear Energy, 1987Abstract A hexagonal geometry extension of the nodal expansion diffusion theory method is presented together with solution and acceleration techniques which have proved effective for 2-D and 3-D fast reactor calculations. The method is based on a radial nodal flux expansion which reflects the inherent symmetry of a hexagon. A 1-D rectangular geometry
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A Three-Dimensional Flux Expansion Nodal Method for Hexagonal Geometry Application
Volume 1: Operations and Maintenance, Aging Management and Plant Upgrades; Nuclear Fuel, Fuel Cycle, Reactor Physics and Transport Theory; Plant Systems, Structures, Components and Materials; I&C, Digital Controls, and Influence of Human Factors, 2016In this paper, a new flux expansion nodal method for hexagonal-z geometry is presented to solve multi-group neutron diffusion equations. In each three dimensional node and each group, the intra-nodal flux is approximated by the linear combination of exponential functions and orthogonal polynomials up to the second order.
Yun Cai +5 more
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Solution of Mathematical Adjoint Equation for a Higher Order Nodal Expansion Method
Nuclear Science and Engineering, 1996A method for determining the mathematical adjoint solution of a higher order nodal expansion method (NEM) based on the simultaneous solution of multigroup equations for each node in the rectangular geometry is presented. In the higher order NEM, the forward NEM equations in a given node include not only the nodal balance and interface-current equations
Taek Kyum Kim, Chang Hyo Kim
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A lattice homogenization procedure using the nodal expansion method and equivalence theory
Annals of Nuclear Energy, 1986Abstract In this paper we give the generalization of the nodal expansion method to incorporate the flux discontinuity factors arising in the equivalence theory formulation of lattice homogenization. The application of equivalence theory to a 2-D uniform lattice in the multigroup diffusion theory approach is shown to yield (in the lowest-order ...
R. Srivenkatesan, S.V.G. Menon
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Annals of Nuclear Energy, 1986
Abstract Convergence of the iteration scheme in the nodal expansion method for the solution of the diffusion equation has been established. The proof is applicable to 1-D, 2-D and 3-D problems with commonly occurring boundary conditions. It is restricted to square and cubic nodes and parabolic expansion of the flux over a node.
R.S. Modak, S.B. Degweker
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Abstract Convergence of the iteration scheme in the nodal expansion method for the solution of the diffusion equation has been established. The proof is applicable to 1-D, 2-D and 3-D problems with commonly occurring boundary conditions. It is restricted to square and cubic nodes and parabolic expansion of the flux over a node.
R.S. Modak, S.B. Degweker
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Error Analysis of the Nodal Expansion Method for Solving the Neutron Diffusion Equation
Nuclear Science and Engineering, 1997Modern nodal methods allow the solution of the few-group neutron diffusion equation in multidimensions to be computed efficiently with high fidelity. This has made possible the routine utilization of three-dimensional analysis for the eigenvalue calculations associated with reload core analysis of light water reactors.
R. Christian Penland +2 more
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A hexagonal geometry nodal expansion method for fast reactor calculations
Progress in Nuclear Energy, 1986Abstract A hexagonal geometry extension of the nodal expansion diffusion theory method is presented together with solution and acceleration techniques which have proved effective for two-dimensional (2D) and three-dimensional (3D) fast reactor calculations. The method uses a radial nodal flux expansion which has hexagonal symmetry. A one-dimensional (
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Higher order polynomial expansion nodal method for hexagonal core neutronics analysis
Annals of Nuclear Energy, 1998Abstract A higher-order polynomial expansion nodal(PEN) method is newly formulated as a means to improve the accuracy of the conventional PEN method solutions to multi-group diffusion equations in hexagonal core geometry. The new method is applied to solving various hexagonal core neutronics benchmark problems.
Jin Young Cho, Chang Hyo Kim
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Improved nodal expansion method for solving neutron diffusion equation in cylindrical geometry
Nuclear Engineering and Design, 2010Abstract The challenges encountered in the development of nodal expansion method (NEM) in cylindrical geometry and the method to circumvent these difficulties are introduced and discussed in this paper. Due to the fact that the azimuthal term contains a factor 1/r2, the traditional transverse integration fails to produce a 1D transverse integrated ...
Dengying Wang +5 more
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