This research focuses on the utilization of thorium-plutonium fuel in pressurized water reactors (PWRs). The reference PWR selected in this research was the Westinghouse AP1000. Thorium-plutonium mixed-oxide (MOX) fuel assemblies partially replaced the uranium oxide fuel assemblies to reduce uranium demand. The cases studied contained 36, 48, 60, 72, and 84 thorium-plutonium MOX fuel assemblies, with the rest of the 193 fuel assemblies loaded with UO2 fuel. The core cycle length, the amount of plutonium incinerated, the amount of generated 233U in the spent fuel, and the conversion ratios were determined using MCNP6. For the different cases, safety parameters such as the power peaking factor and delayed neutron fraction (βeff) were evaluated. The study showed that using thorium-plutonium MOX can achieve good peaking power factors with delayed neutron fractions within the safety limits. Also a conversion factor of about 10% was achieved.