Abstract: An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

Abstract: A bulk hot coke cooler with a vessel for holding the coolant material and a drum rotatably supported within the vessel so that when the drum rotates, it moves through the coolant, the drum having a plurality of hollow cooling pockets going from one side of the drum to the other which directly contact the hot coke in the drum through which pockets coolant can flow as the drum rotates to enhance the cooling effect of the coolant on the hot coke inside the drum, wear sleeves provided on the edges of selected pockets to protect the lead surfaces of the pockets which come in contact with the hot coke, the wear sleeves being shaped to match the shape of the pocket surface where they are attached, and transfer bars connected to the wear sleeves which move and push the coke through the drum. The various parts of the cooler can be fabricated from hardfaced plate.