Embodiments of the present disclosure provide an apparatus comprising: a reaction chamber positioned between a first turbine stage of a power generation system and a turbine stage of the power generation system, wherein the turbine stage comprises a turbine nozzle and a turbine blade row; a plurality of injectors positioned on a wall of the reaction chamber; and a conduit in fluid communication with the plurality of injectors, wherein the conduit delivers at least one of fuel from a fuel supply line to the reaction chamber through the plurality of injectors.