Abstract: A method and apparatus for providing an alternative remote spent fuel pool cooling system for the spent fuel pool. The cooling system is operated to cool the spent fuel pool in the event of a plant accident when normal plant electricity is not available for the conventional fuel pool cooling and cleanup system, or when the integrity of the spent fuel has been jeopardized. The cooling system is operated and controlled from a remote location, which is ideal during a plant emergency.

Abstract: A boiling water nuclear reactor (BWR) multi-stage jet pump mixer assembly according to a non-limiting embodiment of the present invention may include at least one nozzle disposed above a first throat structure which is arranged within a second throat structure. The multi-stage jet pump mixer assembly is configured such that when a drive flow is discharged from the nozzle into the first throat structure, a first suction stage occurs in that a first entrained flow is drawn into the first entrainment entrance and forms a mixed flow. The mixed flow exiting the first throat structure then induces a second entrained flow into the second entrainment entrance during a second suction stage. By employing a multi-stage approach, jet pump efficiency may be improved.

Abstract: Slip joint clamps are installed against guide ears of diffusers at jet pump slip joints. Clamps may prevent vibration and/or movement in the slip joint while not being rigidly attached to the diffuser. Clamps include a compression flipper pressing against a guide ear of the diffuser in a substantially radial direction, a biasing member between the compression member and guide ear that presses the flipper against the guide ear, and supporting structures that hold the flipper and biasing member to the inlet mixer about the guide ear. Systems of slip joint clamps are installed against several guide ears of a single diffuser. Each clamp may radially stabilize the diffuser and inlet mixer while permitting upward relative movement of the inlet mixer. Placement and tensioning of clamps in such systems may be varied so as to prevent or reduce vibrations and/or oscillations between an inlet mixer and diffuser.

Abstract: Slip joint clamps are installed against guide ears of diffusers at jet pump slip joints. Clamps may prevent vibration and/or movement in the slip joint while not being rigidly attached to the diffuser. Clamps include a compression flipper pressing against a guide ear of the diffuser in a substantially radial direction, a biasing member between the compression member and guide ear that presses the flipper against the guide ear, and supporting structures that hold the flipper and biasing member to the inlet mixer about the guide ear. Systems of slip joint clamps are installed against several guide ears of a single diffuser. Each clamp may radially stabilize the diffuser and inlet mixer while permitting upward relative movement of the inlet mixer. Placement and tensioning of clamps in such systems may be varied so as to prevent or reduce vibrations and/or oscillations between an inlet mixer and diffuser.

Abstract: A boiling water nuclear reactor (BWR) multi-stage jet pump mixer assembly according to a non-limiting embodiment of the present invention may include at least one nozzle disposed above a first throat structure which is arranged within a second throat structure. The multi-stage jet pump mixer assembly is configured such that when a drive flow is discharged from the nozzle into the first throat structure, a first suction stage occurs in that a first entrained flow is drawn into the first entrainment entrance and forms a mixed flow. The mixed flow exiting the first throat structure then induces a second entrained flow into the second entrainment entrance during a second suction stage. By employing a multi-stage approach, jet pump efficiency may be improved.

Abstract: An embodiment of the present invention takes the form of a system that may reduce the level of flow-induced vibration (FIV) experienced by a jet pump assembly or other similar object within a pressure vessel. Essentially, an embodiment of the present invention may reduce the slip-joint leakage, which may be a cause of the FIVs, by adding a flow-limiting component to an outlet of the slip joint. This component may take the form of a collar, channel, and/or other component that may be connectable to a component of the jet pump assembly. After installation, an embodiment of the present invention may lower the amplitude of, and/or change the frequency of, the FIVs experienced by the jet pump assembly.