Silicon carbide (SiC) is a possible structural material for application with accident-tolerant fuel for light water reactors, which is expected to decrease heat and hydrogen generation resulting from oxidation reaction with high-temperature steam. In addition to the accident tolerance, SiC is also advantageous for fuel economy because of its small neutron absorption cross-section. We had already reported critical experiments to validate nuclear data libraries. In the present work, we performed sensitivity analyses about the critical experiments for cross-sections related to SiC with a continuous-energy Monte Carlo transportation code. Reactivity worth is defined as the difference of reactivity between a test case with SiC sample rods or aluminum sample rods and a reference case with air rods. Three core configuration experiments, each with a different neutron energy spectrum in sample rod position, were conducted. In the soft spectrum configuration, calculation value of reactivity worth shows good agreement with experimental result. In hard spectrum configurations, however, there are some discrepancies between experimental and calculation results for the reactivity worth of SiC when using air as reference. It was suggested that the discrepancy is mainly affected by thermal neutron absorption cross-section 28Si(n,γ). In the hard spectrum configuration, fast neutron elastic scattering cross-section of SiC is also sensitive to the reactivity worth to the same extent as absorption cross-section.
