What is presented is a high power igniter that releasably secures to a cutting apparatus that is used for radially projecting a flow of heated gas to cut from an internal surface through an external surface of a conduit used for oil, gas, mining, and underwater pressure sealed tool applications. The high power igniter comprises an igniter housing adapted to be positioned in the conduit. The igniter housing comprises a containment sub and a nozzle sub that releasably secure to each other. The nozzle sub for directing the flow of the heated gas toward the cutting apparatus and releasably securing to the cutting apparatus. A high wattage heater in the igniter housing comprises a metal magnalium thermite pellet insertable into the igniter housing for creating the flow of heated gas when the high power igniter is in use and a pellet igniting device.