The implicit restarted Arnoldi method, an efficient alternative to solve the neutron diffusion equation

To calculate the neutronic steady state of a nuclear power reactor core and its subcritical modes, it is necessary to solve a partial eigenvalue problem. In this paper, an implicit restarted Arnoldi method is presented as an advantageous alternative to classical methods as the Power Iteration method and the Subspace Iteration method. The eciency of these methods, has been compared calculating the dominant Lambda modes of several configurations of the Three Mile Island reactor core.