The idea of accident tolerant fuel- cladding combinations is proposed to enhance the safety of light water reactors (LWRs). In this work, niobium as an innovative cladding material instead of zirconium is introduced to uranium oxide (UO2), uranium carbide (UC) and uranium nitride (UN) fuels. MCNPX 2.7 code was used to simulate (UO2- Nb), (UC-Nb) and (UN-Nb) and (UO2-Zr) in an established 17 × 17 PWR lattice. Some important reactor safety aspects such as the effective multiplication factor, reactivity coefficients, control rod worth, soluble boron worth, fission rate, fissile inventory ratio (FIR), axial power profile and radial peaking factor were investigated. The simulation demonstrated that the longest and shortest cycle lengths are delivered by (UO2-Zr) and (UN-Nb) combinations. (UN-Nb) offers the most negativity of FTCs and MTCs (Fuel Temperature Coefficients and Moderator Temperature Coefficients) from 0 to 20 GWd/ton, whereas (UC-Nb) delivers the most negativity of FTCs at the high stages of burnup. The initial control rod worth of (UO2-Zr) is close to that of (UO2-Nb), and greater than that of (UC-Nb) and (UN-Nb) by 16 % and 22 %, respectively. At the end of life (EOL), the axial peak power of (UN-Nb) fuel is found to be greater than that of (UC-Nb) fuel owing to the higher consumption of U-235 in the case of (UN-Nb) fuel. The control of radial power distribution is easier for (UO2-Zr) and (UO2-Nb) fuels owing to the softening of neutron spectrum in these fuels.