Patent Publication Number: US-7712189-B2

Title: High torque small handling pole

Description:
BACKGROUND OF INVENTION 
   1. Field of the Invention 
   This invention relates generally to a tool for handling high torque in a nuclear reactor pressure vessel. 
   2. Description of Related Art 
   Repairs and inspections performed within a reactor pressure vessel (RPV) such as a boiling water reactor (BWR) are generally performed with ropes and poles for manual manipulation of tools and/or delivery of dedicated automated tools. The RPV is generally a cylindrical shaped vessel and is closed at both ends (e.g., a bottom head and a removable top head). During a reactor shut down, the top head of the RPV is removed so as to inspect or repair a selected component within. Other components in the RPV located between a top guide and a core plate or below the core plate may also be removed. To perform the inspections and/or repairs, an operator stands on a bridge positioned over the RPV and lowers the tool using ropes and poles, which may extend about eighty (80) feet below. The ability to perform such inspections and/or repairs depends on the dexterity of the operator. 
   Due to the difficulty in accessing certain locations within the RPV, performing the repairs and/or inspections at such locations can be time consuming and burdensome. It is desirable to limit the time required to perform the repairs and/or inspections in a RPV, due to the enormous daily cost of the reactor being shut down (up to almost a million dollars a day in lost revenue). Reducing the amount of time required to perform such inspections and/or repairs also would facilitate reducing radiation exposure to operators, technicians and maintenance personnel, for example. 
   An approach to repairing and/or inspecting equipments in the RPV has been to use handling poles to attach tools for repairing and servicing. The handling poles are light-weight and thus easy to maneuver within the RPV. Further, handling poles may be designed specifically to handle high-torque. The handling poles may be generally constructed in 10-foot sections and assembled to work in depths of over 80 feet. 
   However, conventional handling poles typically fail at connection joints at approximately 50 ft lbs of torque. Hence, a way to produce higher torque has been to use heavier poles in excess of 130 lbs to deliver the torque. But heavier poles require the use of a overhead crane to assemble the poles and lift the assembled pole to its location. In addition, it may be desirable to keep the weight of the poles as low as possible in order to allow extended use by an operator. Thus, heavier poles are less desirable than the smaller, lighter handling poles. 
   Another approach to generate the high-torque for handling poles has been to use a torque multiplier. However, a torque multiplier is generally larger in size than the smaller handling pole and requires additional readings and calibrations. 
   SUMMARY OF THE INVENTION 
   Exemplary embodiments of the present invention are directed to a handling pole for use in a nuclear reactor. The handling pole may include a pole section, a pole adapter connected to one end of the pole section, and a spade member connected to the other end of the pole section. The pole adapter may include an upper sleeve, and the spade member may include a lower sleeve. 
   Another exemplary embodiment of the present invention is directed to a method for manufacturing a handling pole. The method may include providing a pole section, attaching an adapter pole to one end of the pole section, attaching a spade member to the other end of the pole section, surrounding the adapter pole with an upper sleeve, and surrounding the spade member with a lower sleeve. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Exemplary embodiments of the present invention will become more apparent by describing, in detail, exemplary embodiments thereof with reference to the attached drawings, wherein like procedures are represented by like reference numerals, which are given by way of illustration only and thus do not limit the present invention. 
       FIG. 1A  is a side view of a handling pole in accordance with an exemplary embodiment of the present invention. 
       FIG. 1B  is a cross-section B-B of the handling pole of  FIG. 1A  in accordance with an exemplary embodiment of the present invention. 
       FIG. 1C  is a cross-section C-C of the handling pole of  FIG. 1A  in accordance with an exemplary embodiment of the present invention. 
       FIG. 2  is a cross-section A-A of the handling pole of  FIG. 1A  in accordance with an exemplary embodiment of the present invention. 
       FIG. 3  is a side view of the handling pole rotated in accordance with an exemplary embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
   It should be noted that these Figures are intended to illustrate the general characteristics of method and apparatus of exemplary embodiments of this invention, for the purpose of the description of such exemplary embodiments herein. These drawings are not, however, to scale and may not precisely reflect the characteristics of any given embodiment, and should not be interpreted as defining or limiting the range of values or properties of exemplary embodiments within the scope of this invention. The relative dimensions and size of High Torque Small Handling Pole may be reduced or exaggerated for clarity. Like numerals are used for liked and corresponding parts of the various drawings. 
   Exemplary embodiments of the present invention may provide an apparatus tool for handling and delivering high-torque. The tool can deliver over 100 ft lbs of torque. The tool may be lightweight so as to be assembled by hand and easily manipulated by an operator. The tool may be manipulated without the need of a overhead crane or hoist. The tool may be the same size as an existing tool, and thus interchangeable with existing tool. The tool may be used as a replacement for heavy-weight high torque tool. 
     FIG. 1A  a side view of a handling pole in accordance with an exemplary embodiment of the present invention.  FIG. 1B  is a cross-section B-B of the handling pole of  FIG. 1A  in accordance with an exemplary embodiment of the present invention.  FIG. 1C  is a cross-section C-C of the handling pole of  FIG. 1A  in accordance with an exemplary embodiment of the present invention. 
   Referring to  FIG. 1A , the handling pole  10  includes a pole section  15 , a pole adapter  20  connected at one end and a spade member  40  connected at the other end. As an example, the pole adapter  20  and the spade member  40  may be welded to the pole section  15 . However, it should be appreciated that other attachments may be employed to connect the pole adapter  20  and spade member  40  to the pole section  15 . The entire or section of the handling pole  10  may be composed of a light-weight metal, such as, but not limited to, aluminum. 
   The handling pole  10  is adaptable to produce torque over 100 ft-lb. Each section of the handling pole  10  may be 10 feet in length, and designed to work up to 100 feet depth in the reactor. However, it should be appreciated that each handling pole  10  may be designed as 3 feet, 5 feet or other lengths, depending on the application of the pole. The handling pole  10  may also be the same size as an existing pole, and thus interchangeable with the existing pole (e.g., used for general purpose or non-high torque applications). As a result, the handling pole  10  may reduce the overall job time and may save the cost of developing, building and shipping alternate tooling, such as jet pump breaker poles. 
   It should be appreciated that the handling pole  10  may also be used as a replacement for heavy-weight high torque poles used, for example, in jet pump beam tensioning. The heavy-weight high torque pole is described in co-pending U.S. application entitled “Apparatus and Method for Measuring Rotation During Jet Pump Tensioning”, assigned to General Electric Co., which is hereby incorporated by reference in its entirety. 
     FIG. 2  is a cross-section A-A of the handling pole of  FIG. 1A  in accordance with an exemplary embodiment of the present invention. The pole adapter  20  has a pair of J-shaped slots  25  (only one of which is shown in  FIG. 2 ) which may receive and interlock with a corresponding pin  45  on spade member  40  (adjacent handling pole). The J-shaped slots  25  provide a slot for pin  45  to slide into so as to provide an engagement between adjacent handling poles  10 . The J-shaped slots  25  may be machined into the pole adapter  20 . The pole adapter  20  may be made of, for example, aluminum or any other light-weight metal. 
   An upper sleeve  21  may surround the pole adapter  20  as shown in  FIG. 2  for reinforcement. The upper sleeve  21  may be made from stainless steel so as to prevent the J-shaped slots  25  from spreading (deforming) when torque greater than, for example, 50 ft lbs is applied. It should be appreciated that the upper sleeve  21  may be made from other materials, such as steel, aluminum, engineered plastic materials and/or any combination thereof. 
   The pole adapter  20  includes a pair of dowel pins  27  welded to the upper sleeve at both sides (shown in  FIG. 1B ) to provide attachment to the pole section  15  and to transmit the torque. In other words, the dowel pins  27  penetrate the upper sleeve  21 , the adapter pole  20  and the pole section  15 , and penetrate through the other side (e.g., the pole section  15 , the adapter pole  20  and the upper sleeve  21 ). The dowel pins  27  may be welded to the upper sleeve  21  on both sides to transmit the torque from the J-slot  25  to the pole section  15 . The pins  27  may be made from, for example, but not limited to, stainless steel. The pins  27  may be ¼ inch in diameter. It should be appreciated that other diameter sizes may be employed. 
     FIG. 3  is a side view of the handling pole rotated in accordance with an exemplary embodiment of the present invention. As shown in  FIG. 3 , the upper sleeve  21  and pole adapter  20  includes a drain hole  28 . The drain hole  28  is provided to flush out any fluid trapped in the pole adapter  20 . The drain hole  28  may have a diameter of ¼ inch. It should be appreciated that there may be more than one drain hole  28  in the adapter  20 . It should further be understood by one of ordinary skilled in the art that the size of the drain hole  28  and pins  27  may vary according to the application of the handling pole. 
   Referring again to  FIG. 2 , the pole section  15  is also attached to a spade member  40 . The spade member  40  slidably fits within a thinned section  35  of the pole section  15 . In other words, the spade member  40  may act as a male connector for engaging with the pole adapter  20 . The thinned section  35  of the pole section  15  may be embodied as having a larger bore diameter than the bore diameter of the adapter pole  20 . As an example, the pole section  15  attached to the spade member  40  may have a bore diameter of approximately 0.905 inches and the pole section  15  attached to the adapter pole  20  may have a bore diameter of approximately 0.860 inches. The spade member  40  may be made from, for example, but not limited to, Stainless steel. 
   The spade member  40  includes a spade pin  45  to slidably engage into the J-shaped slots  25 . The spade pin  45  has a dimension to engage with the J-shaped slots  25  and withstand the produced torque without failure. The spade member  40  may be bored with a hole approximately 6 mm through and machined on both sides of the spade member  40  so that the spade pin  45  can be inserted. The spade pin  45  is welded to the spade member  40  at both sides in the machined slot (shown in  FIG. 1C ) so as to prevent buckling. In other words, the spade member  40  is machined with holes and shallow slots on both side of the spade member  40  for spade pin  45  to be inserted and welded within the slot. The spade pin  45  is then centered in the spade member  40  and welded at least in four areas (e.g., on both sides of the spade pin  45  and on both sides of the spade member  40 ). The spade pin  45  may extend approximately 0.178 inches out from the surface of the space member  40 . The spade pin  45  may be made from, for example, but not limited to, stainless steel. It should be appreciated by one skilled in the art that the dimensions of the spade pin  45  may be employed with different sizes. 
   The spade member  40  is attached to the pole section  15  via a pair of lower pins  37 . The lower pins  37  may be similar and may function the same as the dowel pins  27  found in the pole adapter  20 . The area engaging the spade member  40  and the pole section  15  is surrounded with a lower sleeve  30  for reinforcing the connection. The lower sleeve  30  is also attached to the spade member  40  through the pair of lower pins  37 . The pins  37  are welded to the sleeve  30  at both sides to provide attachment to the pole section and to transmit the high torque. In other words, the lower pins  37  may penetrate the lower sleeve  30 , the pole section  15  and then the spade member  40 , and penetrate out the other side (e.g., the spade member  40 , the pole section  15  and then the lower sleeve  30 ). The lower pins  37  are welded to the lower sleeve  30  on both sides to prevent buckling of the thinned area of the section pole  15  and transmit torque through the spade pins  45 . 
   The lower sleeve  30  may be made of, for example, but not limited to, stainless steel, aluminum, steel, engineered plastic materials and/or any combination thereof. In an example, the lower sleeve  30  may be made from the same material as the upper sleeve  21  for ease in manufacturing. The pins  37  may be made from, for example, but not limited to, stainless steel. The lower pins  37  may be ¼ inch in diameter. It should be appreciated that other diameter sizes may be employed. 
   Referring again to  FIG. 1A , the handling pole  10  includes an upper nut  51  and a bottom nut  52 . The upper nut  51  and bottom nut  52  are threaded around the spade member  40 . As a result, the upper nut  51  and bottom nut  52  are used to connect and lock together adjacent handling poles  10 . The bottom nut  52  threads on the handling pole  10  and the upper nut  51  threads on to the bottom nut  52 . The upper and bottom nut is described in detail in co-pending U.S. application entitled “Nut Assembly for Handling Poles and Method Thereof”, assigned to General Electric Co., which is hereby incorporated by reference in its entirety. 
   Exemplary embodiment of the present invention provides the pole adapter having a J-shaped slot which receive and interlock with a corresponding pin on an adjacent handling pole. The J-shaped slot prevents and/or reduces the pole adapter from dis-engaging with the spade member. 
   Exemplary embodiment of the present invention provides a pair of upper pins welded to the upper sleeve at both sides to prevent the pole section from buckling around the upper pins. 
   Exemplary embodiment of the present invention provides a pair of lower pins welded to the lower sleeve at both sides to prevent the pole section from buckling around the lower pins. 
   Exemplary embodiment of the present invention provides the spade member having a spade pin to slidably engage into J-shaped slots. The spade pin welded to the spade member at both sides of the spade member prevents buckling. 
   Exemplary embodiment of the present invention provides machining at least one hole in both sides of the upper sleeve, adapter pole and the pole section, inserting at least one upper pin into the hole, and welding at least one upper pin on the upper sleeve. 
   Exemplary embodiments of the present invention may provide an apparatus tool for handling high-torque over 100 ft lbs. The handling tool may be lightweight so as to be assembled by hand and easily manipulated by the operator without the need of a overhead crane or hoist. 
   The exemplary embodiments of the present invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as departure from the spirit and scope of the exemplary embodiments of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.