Patent Number: 055047882
Section: description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is described with reference to the enclosed Figures wherein the same reference numbers are utilized where applicable. Referring to FIG. 2, the support plate inspection device 10 of the present invention is illustrated. It is to be appreciated by those skilled in the art that the present invention will be utilized to facilitate the easy and rapid inspection of the support plates and tubes of a nuclear steam generator. Typically, the tubes form rows of tube members 24, 24a which are separated by lanes 21, and are retained in position by a plurality of support plates 26. The bottom of each lane typically includes one or more access ports 18 through the which the quenching water exits the generator. This water may have impurities which may corrode or pierce the pipes of the tube sheets, thus resulting in leaks of radioactive superheated water. Such leaks may not be visible to the human eye. Because of the limited access ports, it is difficult for direct human inspection of the pipes to take place. The support plate inspection device 10 of the present invention, in a preferred embodiment, comprises boom means 12 for extending into an access port 18 of a steam generator and into a lane 21 separating two tube sheet members 24, 24a. The boom means is uprightable within the lane 21. A video camera means 30 is attached to the boom means for inspecting the tube members 24, 24a and support plates 26 within the lane 21 when said boom means is uprighted. In a more preferred embodiment, the boom means 22 is multi-sectioned and includes first boom means 14 rotatably coupled to second boom means 16. Boom means 14, 16 are joined by a rotatable joint or connector means 20 such as an elbow joint. The rotatable connector 20 may be activated mechanically via a hand crank, or by means of a pneumatic or hydraulic activator. As shown in FIG. 2, rotatable connector means 20 facilitates the selective vertical rotation of the second boom means 16 with respect to the first boom means 14 within the lane 21. While the present invention has been illustrated in the context of a rotatable elbow joint, it is to be appreciated that the present invention may be utilized with any means for rotating maneuvering the second boom means upwardly relative to first boom means. The first and second boom means 14, 16 are, in one embodiment cylindrical booms members, which enter the steam generator through access port 18 in the wall 23 of the steam generator, and extended within the lane 21 separating two rows of tube members 24, 24a. Wall 23 is typically constructed from steel. The access port may be 1", 2", 4", or 6" in diameter. By enabling access of the inspection device of the present invention through the 1" or 2" access ports, the present invention provides for the inspection of the complete secondary side of the tube sheet and the support plates. As shown in FIGS. 3, 4 and 5, second boom means 16 preferably comprises a plurality of telescoping members 22 which are extendable pneumatically or hydraulically. The multiple telescoping members 22 facilitate the selective vertical or longitudinal adjustment of the second boom means 16 within the tube lane 21. Telescoping members 22 facilitate a full visual inspection of the reactor support plates 26 and tube members 24, 24a. In a preferred embodiment, the second boom means 16 should have telescoping members 22 of sufficient quantity and length to permit the vertical extension of the second boom means 16 of up to approximately 32 feet. This is the typical height of the tubes and will facilitate inspection of the entire tube sheet and all of the support plates. The support plate inspection device 10 further includes a video camera 30 which is attached at or near the distal end of the second telescoping boom means 16, and which transmits video images to a TV monitor located outside of the steam generator. In a preferred embodiment, the video camera will incorporate CCD (charge-coupled device) technology. The advent of CCD (charge-coupled devices) image transducers has permitted television cameras to be fabricated in very small sizes. The CCD detector assembly is positioned to receive optical images from the camera lens so that it can convert the components of the received image to corresponding electrical signals. Electrical circuitry associated with the detectors converts the image component signals to standard video signals for use by television receiver/monitors. In the present invention, the CCD circuitry may, for example, comprise Sony Model A-7560-026A, which functions to convert optical images received from a lens assembly into electrical video signals. The lens assembly of the preferred embodiment, may, for example, comprise Sony Model VCL08SBYA. The distal end of the second boom means 14 supporting the CCD camera further incorporates a pan and tilt means 32, to which video camera 30 is attached. As shown in FIGS. 6 and 7, pan and tilt means 32 facilitates the horizontal 32a and vertical rotation 32b of the video camera 30. In a preferred embodiment, the video camera should be able to pan 359.degree. and tilt approximately 180.degree.. In this manner, the video camera 30 can completely inspect the tube members 24, 24a and support plates 26. In a preferred embodiment, the video camera 30 will also preferably incorporate an auto focus mechanism 34 which, along with the pan and tilt means 32, will be controlled by an operator with a joy stick (not shown) on the outside of the steam generator. FIGS. 6 and 7 further illustrate connecting cables 36 which facilitate the remote operation of the auto focus and pan and tilt mechanism from the joy stock. The cables 36 from the video camera 30 lead to the closed circuit TV monitor located on the outside of the steam generator. Finally, as shown in FIG. 7A, the present invention further includes means 38 for cleaning the tubes 24, 24a and support plates 26. Means 38 will be affixed to the pan and tilt means 32. In a preferred embodiment, means 38 will comprise a nozzle 40 with attached hose 42 which will jet hot water, steam or a chemical cleaner to clean the tube members 24, 24a and support plates 26. The operation of the present invention is now described with reference to the enclosed Figures. As noted above, the present invention is utilized to inspect the support plates 26 and tube members 24, 24a of a nuclear steam generator. Initially, as shown in FIG. 2, the support plate inspection device 10 is inserted through an access port 18 in the wall 23 of the steam generator and through a lane 21 dividing two rows of tube members 24a, 24b. The second telescoping member 16 having the CCD video camera 30 attached thereto is uprighted using rotational connector joint means 20. The rotational joint means 20 may be uprighted using a mechanical crank, or alternatively, with a hydraulic or pneumatic power source. The telescoping second boom means 16 extends upwardly in the lane 21 so as to facilitate the inspection of the support plates and the tube sheet members. The telescoping second boom means 16 can be longitudinally adjusted such that the CCD camera 30 can obtain a full and complete visual inspection of the support plates 26 and complete tubes. The telescoping members 22 should enable the CCD camera to extend vertically approximately 32 feet in order facilitate the full examination of the tubes and support plates. By adjusting the auto focus and pan and tilt means using a joystick situated outside the generator, the CCD camera can fully inspect the tubes 24, 24a sheet and support plates 26. The operator, safely outside the generator, can monitor the inspection on a closed circuit TV camera used in association with the CCD camera 30. By selectively extending the telescoping second boom 16 up to a length approximately 32 feet, the CCD camera 30 can fully inspect each of the four to six support plates which retain the tube sheet members. Means 38 can be utilized to get hot water, steam or chemical cleaner to remove corrosion and dirt from the tube members 24, 24a and support plates 26. When the inspection is completed, the telescoping members 22 are retracted and the second boom means is rotated downward as shown in FIG. 2. The support plate inspection device 10 is withdrawn through access port 18 in wall 23. The procedure may then be repeated by extending the device into another access port 16. The present invention has been described with reference to the enclosed figures and the above-detailed description. It is to be appreciated that numerous modifications and embodiments fall within the spirit of the present invention and that the true nature and scope of the present invention should be determined with reference to the claims appended hereto.