A gas generator driven hydraulic pressure supply device for supplying hydraulic pressure to an operational device that may be associated with a well system and/or an operational device that is located subsea includes an elongated body having an internal bore extending axially from a first end to a discharge end having a discharge port, a gas generator connected at the first end and a hydraulic fluid disposed in the internal bore between a piston and the discharge end so that a portion of the hydraulic fluid is exhausted under pressure through the discharge port in response to activation of the gas generator.