TRIVAC: a model diffusion code for fuel management and design applications

A new three dimensional neutron diffusion code named TRIVAC was set up using advanced discretization algorithms and improved iteration strategies. The two variable order discretization algorithms used in TRIVAC are based respectively on the variational and nodal collocation techniques. These algorithms produce reconstructible solutions which are upper and lower limits of the exact solution. The eigenvalue matrix system is solved using an ADI preconditioning of the power method in conjunction with a symmetric variational acceleration technique. Validation results are reported for the IAEA two- and three-dimensional benchmarks and for a two-dimensional PWR