Neutronic assessment of the use of burnable absorbers for the excess reactivity control in a PWR-type SMR core with TRISO particles

Abstract

In this paper the study of burnable absorbers to control the excess reactivity in a PWR-type SMR core with TRISO particles is performed. Two main options are studied: the use of IBA rods composed by five different burnable poison materials, and IFBA rods composed by ZrB2. The alternatives were compared in terms of cycle length, reactivity swing and radial power distributions. The best alternative found is the use of 556 IFBA rods, which satisfy all the proposed objectives and meets in a better way the basic safety parameters. Furthermore, the control rods worth was evaluated with the insertion of the IFBA rods.