Nuclear Science and Engineering / Volume 155 / Number 2 / February 2007 / Pages 236-249
Technical Paper / Mathematics and Computation, Supercomputing, Reactor Physics and Nuclear and Biological Applications
The design of new generations of nuclear reactors will involve fine representations of the theoretical models. Advanced computational methods capable of solving large-scale problems dealing with large and complex systems are required. Therefore, the solution to challenging large-scale neutron transport problems is becoming more and more pressing in nuclear engineering applications. The increase in high-performance computing resources have made possible direct application of transport methods to large-scale computational models. However, many numerical acceleration techniques common to lattice transport codes are not applicable to three-dimensional geometries with heterogeneous material zones, especially for the eigenvalue problems with high-dominance scattering ratio. Consequently, large heterogeneous reactor problems have remained computationally intensive and impractical for routine engineering applications. One of the alternatives is to use high-performance computing methods to solve such problems in reasonable time.
In this context, we propose an approach based on high-performance computing techniques to solve large-scale neutron transport problems using a three-dimensional characteristics method. A performance model is then introduced to analyze the three-dimensional characteristics solvers in the context of hybrid shared/distributed memory modern architectures. Several numerical results and discussions are presented including a scalability analysis done to predict the performance on a large number of processors.