LAUSR

Abstract In this paper, the SiC reinforced with Hi-Nicalon type S fibers (SiC HNS) was used as fuel cladding, and its behavior from the neutronic viewpoint was compared with the Zircaloy. To evaluate the average temperature of the fuel, cladding, and moderator used in the neutronic studies, a simplified thermal-hydraulic simulation of the core was performed using the RELAP5 code for the two cladding materials. Then, after that, a standard PWR fuel element was simulated, considering normal conditions of operation at Beginning Of Life (BOL) and full power, and using the average temperatures coming from the RELAP5 code calculation. The effects of burnable poison rods and temperature feedback on the core neutron multiplication factor have been evaluated changing the clad material at criticality steady state condition. Finally, the fuel element is analyzed during burnup. The neutronic analysis was made using the SCALE 6.0 (Standardized Computer Analysis for Licensing Evaluation) code.