Abstract: A power vent for a furnace or the like comprises an air inlet tube having axially opposed ends; one end has an air intake opening which will normally locate outdoors; the opposed end connects to the inlet of a blower, with the outlet of the blower connecting to a vent tube. The flue of the furnace connects to the air inlet tube intermediate the ends thereof. The vent tube may suitably locate coaxilly within the inlet tube. The system will normally be sized such that the ratio of fresh air to flue gas is from about 5:1 to about 50:1, and residence times between the flue entry to the air inlet tube and the blower outlet are low, of the order of 0.01 second, thereby reducing the incidence of condensation and icing in the power vent. The system may be balanced, for example by varying the area of the air intake opening, whereby negative pressures within the furnace are avoided, thereby increasing the efficiency of furnace operation.

Abstract: A nuclear reactor system in which the neutron-energy spectrum is displaced towards lower energy (enthalpy) by a control selectively operable by commands outside of the reactor. The core of the reactor contains, in addition to fuel assemblies, sealed tubes filled with helium. The selective control of the neutron energy spectrum includes a master cylinder having a master piston. The master cylinder is immersed in the coolant and admits the coolant through a check valve. The admitted coolant serves as hydraulic fluid of the cylinder. When the external command to shift the neutron-energy spectrum is entered, the master piston compresses the coolant in the master cylinder. The compressed coolant flows into slave cylinders displacing their slave pistons. The slave pistons carry piston rods which drive rupturing tools into engagement with the tubes rupturing the tubes and admitting the coolant which is a neutron moderator and enhances the moderaton of the neutron energy.

Abstract: A composite nozzle for a fuel assembly adapted for installation on the upper or lower end thereof and which is constructed from two components. The first component includes a casting weldment or forging designed to carry handling loads, support fuel assembly weight and flow loads, and interface with structural members of both the fuel assembly and reactor internal structures. The second component of the nozzle consists of a thin stamped bore machine flow plate adapted for attachment to the casting body. The plate is designed to prevent fuel rods from being ejected from the core and provide orifices for coolant flow to a predetermined value and pressure drop which is consistent with the flow at other locations in the core.

Abstract: An arrangement for controlling the moderation of a nuclear reactor which includes multiple fuel assemblies each of which includes top and bottom nozzles with fuel rods and control rod guide thimbles located therebetween. Certain ones of said assemblies include at least one tube initially filled with a gas. One end of the tube rests on the lower nozzle upper surface while the upper end terminates at a point just below the lower plate in the upper nozzle. A spike immovably fixed in the lower plate of the upper nozzle is directed downwardly toward the end of the tube. As the tube expands or grows during operation in a reactor, and at a point where the criticality factor may proceed to less than one, the expanded tube will be pierced by the spike and thus permit the escape of gas from the tube which is then replaced by water coolant circulating through the reactor.

Abstract: An arrangement for controlling the moderation of a nuclear reactor which includes multiple fuel assemblies each of which includes top and bottom nozzles with fuel rods and control rod guide thimbles located therebetween. Certain ones of said assemblies include at least one tube initially filled with a gas. One end of the tube rests on the lower nozzle upper surface while the upper end terminates at a point just below the lower plate in the upper nozzle. A spike immovably fixed in the lower plate of the upper nozzle is directed downwardly toward the end of the tube. As the tube expands or grows during operation in a reactor, and at a point where the criticality factor may proceed to less than one, the expanded tube will be pierced by the spike and thus permit the escape of gas from the tube which is then replaced by water coolant circulating through the reactor.