Parallel Solution of the Multigroup Neutron Diffusion Equations

This project has involved the implementation of parallel solution methods, in particular parallel Multigrid and Krylov-subspace methods, for the efficient solution of the three-dimensional transient multigroup neutron diffusion equations, which are used to model the distribution of the neutrons in a nuclear reactor core. This project was supported in part by the Siemens AG, Munich, and a Leonardo da Vinci scholarship from the European Union. Mathematically those equations form a non-symmetric system of 2nd-order parabolic partial differential equations, which is discretised using a non-standard mixed finite volume discretisation technique. The calculation of the initial condition for this system involves the solution of a generalised eigenvalue problem. The task to construct an efficient parallel iterative solution method for the resulting large non-symmetric linear equation systems was therefore very challenging. We were able to report a competitive sequential performance of our methods, and the parallel efficiency of the methods is optimal for up to 10 processors.


The code, which implements the developed methods, has been included (by Dr. M. Paffrath) into the nuclear power plant simulation code RELAP5/PANBOX of the Siemens AG Operating Division KWU, which is used for the safety analysis and control of nuclear power plants. The performance of the methods within this package and further strategies to enhance the efficiency have also been presented (by Dr. H. Finnemann) on the Annual Meeting of the American Nuclear Society 1999 in Boston:
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Last updated 03/04/2002