Abstract: In one general aspect, various embodiments of the present invention can include a motorized surgical cutting and fastening instrument having a drive shaft, a motor selectively engageable with the drive shaft, and a manual return mechanism configured to operably disengage the motor from the drive shaft and retract the drive shaft. In at least one embodiment, a surgeon, or other operator of the surgical instrument, can utilize the manual return mechanism to retract the drive shaft after it has been advanced, especially when the motor, or a power source supplying the motor, has failed or is otherwise unable to provide a force sufficient to retract the drive shaft.

Abstract: A laser inertial-confinement fusion-fission energy power plant is described. The fusion-fission hybrid system uses inertial confinement fusion to produce neutrons from a fusion reaction of deuterium and tritium. The fusion neutrons drive a sub-critical blanket of fissile or fertile fuel. A coolant circulated through the fuel extracts heat from the fuel that is used to generate electricity. The inertial confinement fusion reaction can be implemented using central hot spot or fast ignition fusion, and direct or indirect drive. The fusion neutrons result in ultra-deep burn-up of the fuel in the fission blanket, thus enabling the burning of nuclear waste. Fuels include depleted uranium, natural uranium, enriched uranium, spent nuclear fuel, thorium, and weapons grade plutonium. LIFE engines can meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the highly undesirable stockpiles of depleted uranium, spent nuclear fuel and excess weapons materials.

Abstract: A fuel pebble for use in a fusion-fission engine includes a buffer material and a fertile or fissile fuel shell surrounding the buffer material. The fuel pebble also includes a containment shell surrounding the fertile or fissile fuel shell. The containment shell includes silicon carbide. The fuel pebble further includes a composite material layer surrounding the containment shell and a cladding layer surrounding the composite material layer.

Abstract: A fuel particle for use in a fusion-fission nuclear engine includes a fuel kernel and a buffer layer surrounding the fuel kernel. The fuel particle also includes a pyrolytic carbon layer surrounding the buffer layer and a silicon carbide layer surrounding the buffer layer. The silicon carbide is characterized by a stress less than 450 MPa at 95% burn-up. The fuel particle further includes a second pyrolytic carbon layer surrounding the silicon carbide layer.