[3F11-13] Core Design 2 (Breeder Reactor)

[3F11] Preliminary Study of Super FBR with Multi-Axial Fuel Shuffling

*Shogo Noda¹, Takayuki Someya², Akifumi Yamaji¹ (1. Department of Applied Physics, School of Advanced Science and Engineering, Waseda University, 2. Cooperative Major in Nuclear Energy Graduate School of Advanced Science and Engineering, Waseda University)

Keywords:Multi-Axial Fuel Shuffling, Supercritical Light Water Reactor, Fast Breeder Reactor, CSDT

Because the water density in a supercritical light water reactor (SCWR) changes largely, it is possible to design the fast breeder reactor of SCWR (Super FBR) which utilizes the upper region of the core, in which there are fast neutrons. In this study, we investigate the core concept of Super FBR which has some blanket layers in the axial position of MOX fuel assembly (FA) and the multi-axial fuel shuffling concept, in which the upper core (blanket FA) and the lower core (MOX main FA) are shuffled independently, and evaluate the influence on Compound System Doubling Time (CSDT). The core characteristics are evaluated by the calculation coupled with neutronics and thermal-hydraulics core calculations. A neutronics calculation consists of SRAC2006, ASMBURN, COREBN codes, which base on a collision probability method, a macroscopic cross section interpolation method and a neutronic diffusion approximation. A thermal-hydraulics calculation consists of the single channel analysis of a hot channel and an average power channel. As a result, the characteristic that to design the batch number of the upper blanket core appropriately makes RDT and CSDT short becomes obvious.