Investigation of Thorium Utilization in a New SMR Core Design – O.S. Çelikten, S. Ergün

Thorium is considered to be a key element in future nuclear technology because of huge amount of reserves in the world. Several investigations have been performed by many of researcher groups around the world for Th-U breeding including the ones in Turkey. In addition, Turkey has one of the biggest thorium reserves in the world, therefore it is important to work on Th utilization for Turkey’s reactors. Small modular reactors (SMRs) are standardized, easy to construct and inherently safe new innovative designs. Because of these, a new core design of an SMR is performed in this study. The aim of the study is to determine the basic cell configuration and maximum 232Th to 233U conversion with most promising SMR design parameters and to reach conversion ratio up to 1. In this study, criticality and burnup calculations were performed with MCNP6.1.1 code system which includes CINDER burnup module with newly generated cross-section sets by NJOY99. Heterogeneous core design (axial pellet type variation or pin based designs) was performed since it is important for neutronic aspects when thorium is added to the nuclear reactor fuel to increase conversion. To this respect, 3D pincell simulations were performed for different heterogeneous neutronic design cases.