Reducing separated weapon grade (WG) plutonium is very crucial since this plutonium may be misused and/or released accidentally into the environment. Burning WG plutonium in nuclear reactors can help to solve this serious problem effectively. In this study, the incineration of WG plutonium mixed with thorium in a (DT) fusion driven high power density hybrid reactor was investigated for an operation period of 24 months. Furthermore, the effect of using different coolants on the burning of WG plutonium in the hybrid blanket was examined. Numerical calculations showed that WG plutonium can be denatured to reactor grade level within a very short time by using a high power density hybrid reactor. Moreover, addition of WG plutonium to thorium improved the neutronic performance of the reactor significantly.