The power pulse characteristics following a large loss-of-coolant accident have been analyzed for a Canada deuterium uranium (CANDU)-6 reactor core fueled with a CANDU flexible fueling recovered uranium fuel. The coupled simulations for the reactor physics and channel thermal-hydraulics phenomena are done using the RFSP and CATHENA codes. The 55% pump suction, 35% reactor inlet header, and 100% reactor outlet header breaks were selected. From the analysis results, it is known that the shutoff rods have enough reactivity for a reactor shutdown and to maintain it at a subcriticality state. Even with the highest power pulse, which occurred in a 100% reactor outlet header break, the fuel temperature was maintained below the fuel melting temperature. The summation of the initial stored energy and the transient pulse energy of the hottest fuel pin has a minimum 17% margin for the fuel breakup.