Simulation of reactor antineutrino signatures is vital to verify the experimental measurements of antineutrinos emitted from a reactor. It also provides an insight into detector configurations required to monitor different reactor types and potential fuel diversion scenarios. In this study, we perform simulations of antineutrino signatures for light water reactors (LWRs) using the industry standard reactor simulation tools, CASMO-4 and SIMULATE-3. Three different LWR reactors have been modeled, and several diversion scenarios involving uranium dioxide and mixed-oxide fuel have been simulated. The simulation results are also benchmarked with the antineutrino counts measured by the SONGS1 antineutrino detector that was used to monitor the operation of San Onofre Nuclear Generating Station (SONGS), unit 2, cycle 13, during the period 2004-2005. Three-dimensional simulations of the reactor cores have been performed for improved accuracy of the detector response. The dependence of the antineutrino rate on the reactor type, fuel loading pattern, and amount of fresh fuel have also been analyzed.