Criticality calculations for the TRIGA Mark-II reactor of ITU by the finite element and finite difference methods

In this study, TRIGA Mark-II reactor of the Istanbul Technical University is treated in cylindrical geometry. Using two-region and ten-region models C23 of this reactor, both FDM and FEM have been utilized to solve multiplication eigenvalue problems. Polynomial approximations up to degree ten have been used in the FEM solutions. Such high degree polynomial approximations are not reported in the literature, perhaps due to the difficulty of assembling the coefficient matrix. By the use of the computer also in the formulation of the problem, such high degree approximations are made possible. The relative computer execution times of FDM and various degree FEM solutions are compared and their relative merits in TRIGA calculations are assessed. Both consistent and lumped source variety FEM solutions are obtained