Devices position inspection and operation tools in a nuclear reactor without use of a bridge or other maintenance structure well above the reactor core. Devices can selectively join to in-reactor structures like steam dams through clamping that permits limited movement. Positioning assemblies may be supported by the devices. The positioning assembly includes a mast that moves relative to the positioning assembly. Rollers of the positioning assembly may so move the mast. The positioning assembly may be rotated with a sun gear having an exterior surface about which the mast and rollers can revolve. A local motor or external drive may provide power for this rotation and/or revolving as well as rotation of the rollers to move the mast and assembly. Devices are useable underwater or submerged in fluid and may include instruments with powering lines or mechanical extensions that permit powering or direct interfacing from operators outside the reactor.

A method of locating a remotely operated vehicle within a workspace includes the steps of: receiving a video feed of the workspace from a video camera; processing the video feed to identify landmarks and features of known physical structures in or near the workspace; determining a correlation between the features and landmarks and known physical structures; calibrating the video feed from the camera to the known physical structures using the correlation; determining the location in the calibrated video feed of a number of fiducial markers on the remotely operated vehicle; and determining the position of the remotely operated vehicle within the workspace using the location of the number of fiducial markers in the calibrated video feed.

An improved tool for delivery of a testing element to a limited access location within a nuclear containment includes a rotation apparatus having a connection element that is configured to have an aperture that is formed generally centrally therein. The aperture is structured to receive therein a cable that extends from a testing element, which that avoids the need to use slip rings or similar devices to permit the testing element to carried on a pivotable and rotatable structure. Moreover, an improved submersible machine is structured to carry the tool to a limited access location within a nuclear containment.

An improved tool for delivery of a testing element to a limited access location within a nuclear containment includes a rotation apparatus having a connection element that is configured to have an aperture that is formed generally centrally therein. The aperture is structured to receive therein a cable that extends from a testing element, which that avoids the need to use slip rings or similar devices to permit the testing element to carried on a pivotable and rotatable structure. Moreover, an improved submersible machine is structured to carry the tool to a limited access location within a nuclear containment.

According to one embodiment disclosed in the present inventive concept, a method for diagnosing the lifespan of a pressure vessel is disclosed. The method for diagnosing the lifespan of the pressure vessel includes the steps of extracting a calorimetric sample from the pressure vessel or a surveillance test specimen, measuring the enthalpy amount, changes in the enthalpy amount, the specific heat capacity, or changes in the specific heat capacity of the extracted calorimetric sample; determining the amount of entropy change in the calorimetric sample based on the measured enthalpy amount, the measured changes in the enthalpy amount, the measured specific heat capacity, or the measured changes in the specific heat capacity; and determining the remaining lifespan of the pressure vessel based on the amount of entropy change in the calorimetric sample. In addition, various embodiments discernible through the specification are possible.

According to one embodiment disclosed in the present inventive concept, a method for diagnosing the lifespan of a pressure vessel is disclosed. The method for diagnosing the lifespan of the pressure vessel includes the steps of extracting a calorimetric sample from the pressure vessel or a surveillance test specimen, measuring the enthalpy amount, changes in the enthalpy amount, the specific heat capacity, or changes in the specific heat capacity of the extracted calorimetric sample; determining the amount of entropy change in the calorimetric sample based on the measured enthalpy amount, the measured changes in the enthalpy amount, the measured specific heat capacity, or the measured changes in the specific heat capacity; and determining the remaining lifespan of the pressure vessel based on the amount of entropy change in the calorimetric sample. In addition, various embodiments discernible through the specification are possible.

The invention relates to an apparatus and methods for operation in relatively high radiation fields to remotely switch signal devices through a shared single main umbilical signal cable. The invention is particularly suitable for use in a nuclear reactor, such as a boiling water reactor, and in difficult to access areas in the reactor pressure vessel. One or more main umbilical cables connect a control station to an enclosure housing a signal switching device. The signal switching device allows several signal generating/receiving devices, such as cameras and ultrasonic probes, to be controlled by the one or more main umbilical cables.

The invention relates to an apparatus and methods for operation in relatively high radiation fields to remotely switch signal devices through a shared single main umbilical signal cable. The invention is particularly suitable for use in a nuclear reactor, such as a boiling water reactor, and in difficult to access areas in the reactor pressure vessel. One or more main umbilical cables connect a control station to an enclosure housing a signal switching device. The signal switching device allows several signal generating/receiving devices, such as cameras and ultrasonic probes, to be controlled by the one or more main umbilical cables.

The invention relates particularly to a device (3) for controlling and measuring welding defects on a cylindrical wall (140) such as a vessel bottom penetration (14) wall) (140) of a nuclear reactor, said device comprising a control head (4) forming a probe which has a proximal end (EP) and a distal end (ED), along the longitudinal axis (X-X) thereof, and includes a first side (42), a so-called inner side, provided with at least one ultrasonic wave translator, characterized in that: said control head (4) comprises a second side (43), a so-called outer side, opposing the first side (42), which has a curved surface in the form of a cylinder fraction, with a longitudinal axis parallel to the longitudinal axis (X-X) of the head (4) and an outwardly facing convexity; said wave translator consists of a series (5) of adjacent elements (50), each element (50) being both an emitter and a receiver, said series (5) having a curved surface in the form of a cylinder fraction in the same direction as said longitudinal axis (X-X) and an outwardly facing concavity; and the plane (P1) containing the two end generatrices of the cylinder fraction of the second side (43) forms a non-null acute angle with the plane (P2) containing the two end generatrices of said cylinder fraction of the wave translator (5).

The invention relates particularly to a device (3) for controlling and measuring welding defects on a cylindrical wall (140) such as a vessel bottom penetration (14) wall) (140) of a nuclear reactor, said device comprising a control head (4) forming a probe which has a proximal end (EP) and a distal end (ED), along the longitudinal axis (X-X) thereof, and includes a first side (42), a so-called inner side, provided with at least one ultrasonic wave translator, characterized in that: said control head (4) comprises a second side (43), a so-called outer side, opposing the first side (42), which has a curved surface in the form of a cylinder fraction, with a longitudinal axis parallel to the longitudinal axis (X-X) of the head (4) and an outwardly facing convexity; said wave translator consists of a series (5) of adjacent elements (50), each element (50) being both an emitter and a receiver, said series (5) having a curved surface in the form of a cylinder fraction in the same direction as said longitudinal axis (X-X) and an outwardly facing concavity; and the plane (P1) containing the two end generatrices of the cylinder fraction of the second side (43) forms a non-null acute angle with the plane (P2) containing the two end generatrices of said cylinder fraction of the wave translator (5).