The present disclosure relates to an L-shaped header of a steam generator including a spiral heat transfer tube, and a coupling structure between the L-shaped header and the heat transfer tube, wherein an upper end and a lower end of a heat transfer tube assembly configured with a plurality of heat transfer tubes are vertically formed, and the upper and lower ends of the heat transfer tube assembly are vertically coupled to a bottom side or a top side of the header. Therefore, the heat transfer tubes constituting the same concentric circle may use the heat transfer tubes formed with the same shape, thereby improving the manufacturability of parts and reducing the manufacturing cost.

A manipulator configured to navigate a heat exchanger including a plurality of tubes extending through a tubesheet is disclosed herein, the manipulator including a first end effector, a second end effector, and an articulation assembly. The first end effector is configured to accommodate an instrument configured to service the heat exchanger and includes a first actuator configured to extend a first gripper into a tube of the plurality of tubes. The second end effector includes a second actuator configured to extend a second gripper into a tube of the plurality of tubes. The first and second gripper are configured to secure the manipulator to the tubesheet, and, when the second gripper is securing the manipulator to the tubesheet, the articulation assembly is configured to enable the first end effector to move relative to the second end effector in a plane that is parallel to the tubesheet.

A power conversion system for converting thermal energy from a heat source to electricity is provided. The system includes a chamber including an inner shroud having an inlet and an outlet and defining an internal passageway between the inlet and the outlet through which a working fluid passes. The chamber also includes an outer shroud substantially surrounding the inner shroud. The chamber includes a source heat exchanger disposed in the internal passageway, the source heat exchanger being configured to receive a heat transmitting element associated with the heat source external to the chamber, and to transfer heat energy from the heat transmitting element to the working fluid. The system also includes a compressor disposed adjacent the inlet of the inner shroud and configured to transfer energy from the compressor to the working fluid, and an expander disposed adjacent the outlet of the inner shroud.

A power conversion system for converting thermal energy from a heat source to electricity is provided. The system includes a chamber including an inner shroud having an inlet and an outlet and defining an internal passageway between the inlet and the outlet through which a working fluid passes. The chamber also includes an outer shroud substantially surrounding the inner shroud. The chamber includes a source heat exchanger disposed in the internal passageway, the source heat exchanger being configured to receive a heat transmitting element associated with the heat source external to the chamber, and to transfer heat energy from the heat transmitting element to the working fluid. The system also includes a compressor disposed adjacent the inlet of the inner shroud and configured to transfer energy from the compressor to the working fluid, and an expander disposed adjacent the outlet of the inner shroud.

Apparatus for a steam generator that employs tube support plates within a shroud that is in turn disposed within a shell. The tube support plates are made of a material having a coefficient of thermal expansion lower than that of the shroud. The tube support plates are aligned during fabrication, with minimal clearances between components. Using a tube support displacement system, a controlled misalignment is then imposed on one or more tube support plates, as the steam generator heats up. The tube support plate displacement system has only one part, a push rod, which is internal to the steam generator shroud, thereby minimizing the potential of loose parts. The tube support plate displacement system can be used to provide controlled misalignments on one or more tube support plates, in the same or varying amounts and directions, and with one or more apparatus for each individual tube support plate.

A plurality of signal anomalies are identified in a number of tubes in a steam generator. Since the geometry of the steam generator is known, the location of each signal anomaly along each tube is converted into a location within the interior of the steam generator. If a plurality of signal anomalies are at locations within the steam generator that are within a predetermined proximity of one another, such a spatial confluence of signal anomalies is determined to correspond with a loose part situated within the steam generator. Additional methodologies can be employed to confirm the existence of the loose part. Historic tube sheet transition signal data can be retrieved and subtracted from present signals in order to enable the system to ignore the relatively strong eddy current sensor signal of a tube sheet which would mask the relatively weak signal from a loose part at the tube sheet transition.

A neutron absorbing insert for use in a fuel rack. In one aspect, the insert includes: a plate structure having a first wall and a second wall that is non-coplanar to the first wall; the first and second walls being formed by a single panel of a metal matrix composite having neutron absorbing particulate reinforcement that is bent into the non-coplanar arrangement along a crease; and a plurality of spaced-apart holes formed into the single panel along the crease prior to bending.

The method includes installing a system for inspecting the core shroud on the core shroud, driving the system horizontally around the core shroud, and using a sensor of the system to inspect the core shroud, where the system includes a trolley, an arm, a tether, and a remotely operated vehicle (ROV) for inspecting the core shroud. The ROV includes a body configured to be operatively connected to the tether, and the sensor is configured to be operatively connected to the body, and configured to provide inspection information of the core shroud. The arm is configured to be operatively connected to the trolley. The ROV is configured to be operatively connected to the arm via the tether, and the tether is configured to provide vertical position information for the ROV relative to the outer surface of the core shroud.

A plurality of signal anomalies are identified in a number of tubes in a steam generator. Since the geometry of the steam generator is known, the location of each signal anomaly along each tube is converted into a location within the interior of the steam generator. If a plurality of signal anomalies are at locations within the steam generator that are within a predetermined proximity of one another, such a spatial confluence of signal anomalies is determined to correspond with a loose part situated within the steam generator. Additional methodologies can be employed to confirm the existence of the loose part. Historic tube sheet transition signal data can be retrieved and subtracted from present signals in order to enable the system to ignore the relatively strong eddy current sensor signal of a tube sheet which would mask the relatively weak signal from a loose part at the tube sheet transition.

A steam generator includes a shroud and an annular stepwise helical baffle extending along at least part of a length of the shroud. There is a riser located in a central region of the steam generator. The helical baffle is made up of at least one annular sector of flat plates. The edges of the flat plates may be straight or corrugated.