Abstract:
The present invention relates to a machining, examination, and welding integral device for a nozzle, and more particularly, to a machining, examination, and welding integral device for a nozzle in which machining, examination, and welding can be made in the nozzle by one device. To this end, there is provided a machining, examination, and welding integral device for a nozzle including: a pair of caps provided to be separated from each other; a welding unit provided between the pair of caps to weld a junction part of the nozzle and a pipe; a examination unit coupled to one side of the welding unit to check whether the junction part is defective; and a machining unit coupled to the top of the welding unit to remove the surface of a welded portion of the junction part and/or process the welded portion of the junction part.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of Korean Patent Application No. 10-2012-0137777 filed in the Korean Intellectual Property Office on Nov. 30, 2012, the entire contents of which are incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to a machining, examination, and welding integral device for a nozzle, and more particularly, to a machining, examination, and welding integral device for a nozzle in which machining, examination, and welding can be made in the nozzle by one device. 
       BACKGROUND OF THE INVENTION 
       [0003]      FIG. 1  is a perspective view illustrating a reactor vessel in a nuclear power plant in the related art. 
         [0004]    In general, a primary-side main facility of a westinghouse type nuclear power plant includes a reactor vessel  100 , and a total of six nozzles  110  of three inlet nozzles and three outlet nozzles on an outer periphery of the top of the reactor vessel  100 . 
         [0005]    Further, the six nozzles  110  mounted on the reactor vessel  100  and a pipe  130  are connected with each other by a dissimilar metal weld part  120 . 
         [0006]    Herein, the reactor vessel  100 , the pressurizer, the steam generator, the coolant pump, and the like are made of low carbon steel and a main pipe is made of stainless steel. 
         [0007]    Further, the dissimilar metal weld parts  120  connecting the nozzle  110  and the pipe  130  are welded to each other by an alloy 82/182 material that can buffer different mechanical properties of materials. 
         [0008]    However, according to an apparatus having a configuration in the related art, with an increase in operating years of the nuclear power plant, primary water stress corrosion cracking in the dissimilar metal weld parts  120  gradually increases. 
         [0009]    Since an operator needs to approach an inner part of the reactor vessel to replace each of machining, examination, and welding devices which are independently configured according to a required process in order to remove the aforementioned defect, there was a problem in that an error may occur in an operating position according to the device. 
         [0010]    Since a safety of the operator is significantly influenced by the vicinity of a nozzle part of the reactor vessel as a zone which is polluted by radioactivity, there was a problem in that it is difficult to perform repairing by hand. 
       SUMMARY OF THE INVENTION 
       [0011]    The present invention is contrived to solve the problem in the related art, and the present invention has been made in an effort to provide a machining, examination, and welding integral device for a nozzle in which a machining device, a examination device, and a welding device are integrally provided in one housing, and as a result, an appropriate device can be used at the same operating position according to a process. 
         [0012]    Further, the present invention has been made in an effort to provide a machining, examination, and welding integral device for a nozzle in which an operation is performed by moving the machining, examination, and welding integral device for a nozzle into the nozzle in a reactor vessel with a conveyance positioner to perform a safe operation. 
         [0013]    In order to achieve the object, an exemplary embodiment of the present invention provides a machining, examination, and welding integral device for a nozzle including: a pair of caps provided to be separated from each other; a welding unit provided between the pair of caps to weld a junction part of the nozzle and a pipe; a examination unit coupled to one side of the welding unit to examine whether the junction part is defective; and a machining unit coupled to the top of the welding unit to remove the surface of a welded portion of the junction part and/or process the welded portion of the junction part. 
         [0014]    Foreign substance preventing layers may be provided on surfaces of the pair of caps facing each other. 
         [0015]    A support member may be provided between the welding unit and the foreign substance preventing layer. 
         [0016]    The machining, examination, and welding integral device for a nozzle may further include a control unit controlling the welding unit, the machining unit, and the examination unit. 
         [0017]    The control unit may include a first control unit connected to the outside to control a machining condition, a welding route, and a welding condition through an embedded program; and a second control unit connected with the first control unit and provided in the cap, and transmitting signals to the examination unit, the welding unit, and the machining unit. 
         [0018]    The welding unit, the machining unit, and the examination unit may be rotatable along an inner wall of the nozzle at 360°. 
         [0019]    The machining, examination, and welding integral device for a nozzle may be inserted into the nozzle by a conveyance positioner installed in a reactor vessel. 
         [0020]    The conveyance positioner may include a seating part on which the machining, examination, and welding integral device for a nozzle is seat for conveyance; a vertical guide unit installed on the bottom of the seating part to vertically drive the seating part; and a rotating plate rotating the seating part. 
         [0021]    The junction part may be welded by using alloy 52/152 in order to prevent PWSCC. 
         [0022]    According to the machining, examination, and welding integral device for a nozzle of the present invention, there is provided a machining, examination, and welding integral device for a nozzle in which the machining device, the examination device, and the welding device are integrally provided in the housing and the operator performs an operation by controlling the machining device, the examination device, and the welding device through the control unit according to the required process, and as a result, since the operator does not replace the required devices according to the process, the devices required according the processes can perform the operation at the same operating position. 
         [0023]    Further, there is provided a machining, examination, and welding integral device for a nozzle in which since the operator does not perform the operation in a zone polluted by radioactivity while an operation is performed by moving the machining, examination, and welding integral device for a nozzle with the conveyance positioner, a safe operation is performed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1  is a perspective view illustrating a reactor vessel in a nuclear power plant in the related art; 
           [0025]      FIG. 2  is a front view illustrating a machining, examination, welding integral device for a nozzle according to the present invention; 
           [0026]      FIG. 3  is a plan view illustrating the machining, examination, welding integral device for a nozzle according to  FIG. 2 ; 
           [0027]      FIG. 4  is a perspective view illustrating a conveyance positioner to which the machining, examination, and welding integral device for a nozzle of  FIG. 2  are conveyed; and 
           [0028]      FIG. 5  is a perspective view illustrating a state in which the conveyance positioner and the machining, examination, and welding integral device for a nozzle are mounted, which are installed in a reactor vessel. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0029]    Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings and contents to be described below. However, the present invention is not limited to the exemplary embodiment described herein but embodied as another form. Still, the exemplary embodiment introduced herein is provided to make the disclosed contents to be fully complete and the spirit of the present invention is sufficiently conveyed to those skilled in the art. Throughout the specification, like reference numerals refer to like elements. 
         [0030]      FIG. 2  is a front view illustrating a machining, examination, welding integral device  200  for a nozzle according to the present invention.  FIG. 3  is a plan view illustrating the machining, examination, welding integral device  200  for a nozzle according to  FIG. 2 . 
         [0031]    As illustrated in  FIG. 2 , the machining, examination, and welding integral device  200  for a nozzle includes a pair of caps  210  separated from each other to form a receiving part  212 , a pair of foreign substance prevention layers  220  formed on surfaces of the pair of caps  210  that face each other, a pair of supporting members  230  fixing the machining, examination, and welding integral device  200  for a nozzle onto an inner wall of a nozzle  110  on the pair of foreign substance preventing layers facing each other, and a tool stand  240  received in the receiving part  212 . 
         [0032]    The tool stand  240  includes a welding unit  242  welding a junction part  120 , which is formed on the bottom, a examination unit  244  examination whether the welding of the junction part  120  is defective, which is formed on the top, a machining unit  246  removing an existing welding portion and newly machining the corresponding portion, which is formed on one side, and a chip collector  248  vacuum-suctioning a by-product generated by the machining unit  246 . 
         [0033]    A second control unit  214  controlling the welding unit  242 , the machining unit  246 , and the examination unit  244  is provided in the pair of caps  210 . 
         [0034]    Herein, the welding unit  242 , the machining unit  246 , and the examination unit  244  weld, process, and examine the inner wall of the junction part  120  between the nozzle  110  and a pipe  130  and thus may move along the inner wall of the junction part  120  at 360°. 
         [0035]    Further, the welding unit  242 , the machining unit  246 , and the examination unit  244  are controlled by a first control unit (not illustrated), and the first control unit is connected with the second control unit  214  outside a reactor vessel  100 , and as a result, an operator controls examination driving, a machining condition, a welding route, and a welding condition through a control program embedded in the first control unit outside the reactor vessel  100 . 
         [0036]    A signal controlled by the first control unit is received by the second control unit  214  provided in the cap  210  directly connected with the welding unit  242 , the machining unit  246 , and the examination unit  244 , and the second control unit  214  transfers the received signal to any one device of devices that perform corresponding operations, that is, the welding unit  242 , the machining unit  246 , and the examination unit  244 . 
         [0037]    While the pair of foreign substance preventing layers  220  are contracted, the pair of foreign substance preventing layers  220  are expanded to separate into a service space and a service-out space, foreign substances generated in machining and welding are prevented from flowing out to the outside of the service space, and external compressed air is supplied to the inside of the service space. 
         [0038]    A plurality of support stands  232  formed to protrude radially at the center is provided in the pair of support members  230 , the support stands  232  are configured in two layers to be fixed onto the inner wall of the nozzle  110 , and at least the three support stands  232  are preferably provided radially at the center so as for the support members  230  to safely support the machining, examination, and welding integral device  200  for a nozzle. 
         [0039]    The machining, examination, and welding integral device  200  for nozzle which is configured as described above is moved by a conveyance positioner  300  device to move to the inside of the nozzle  110  of the reactor vessel  100 . 
         [0040]    A detailed configuration of the conveyance positioner  300  will be described below with reference to  FIG. 4 . 
         [0041]      FIG. 4  is a perspective view illustrating the conveyance positioner  300  to which the machining, examination, and welding integral device  200  for a nozzle is conveyed. 
         [0042]    As illustrated in  FIG. 4 , the conveyance positioner  300  is a device which is coupled to the inside of the reactor vessel  100  to move the machining, examination, and welding integral device  200  for a nozzle to the inside of the nozzle  110 . 
         [0043]    The conveyance positioner  300  includes a seating part  310  on which the machining, examination, and welding integral device  200  for a nozzle is seat, a vertical guide unit  320  installed on the bottom of the seating part  310  to vertically drive the seating part  310 , and a rotating plate  330  rotating the seating part  310 . 
         [0044]    Further, a shaft driver  340  is coupled in a vertical direction at a terminal of the seating part  310 , the shaft driver  340  is connected with a terminal of the cap  210  of the machining, examination, and welding integral device  200  for a nozzle, and the machining, examination, and welding integral device  200  for a nozzle is inserted into the nozzle  110  by pressurizing the machining, examination, and welding integral device  200  for a nozzle by using the shaft driver  340 . 
         [0045]      FIG. 5  is a perspective view illustrating a state in which the conveyance positioner  300  and the machining, examination, and welding integral device  200  for a nozzle mounted are mounted, which are installed in a reactor vessel. 
         [0046]    As illustrated in  FIG. 5 , cooling water is filled in a nuclear fuel refilling water tank, the conveyance positioner  300  is inserted into the reactor vessel  100  and thereafter, the conveyance positioned is fixed by using a flange surface of a reactor vessel so as to move the machining, examination, and welding integral device  200  for a nozzle from an inlet/outlet of the reactor vessel  100  to the inside of the nozzle  110  while nuclear fuel in the reactor vessel  100  and internals in the reactor vessel  100  which is drawn out. 
         [0047]    Thereafter, the machining, examination, and welding integral device  200  for a nozzle is seated on the seating part  310  of the conveyance positioner  300 , the machining, examination, and welding integral device  200  for a nozzle moves down to an inlet of the nozzle  110  by using the vertical guide unit  320  provided on the bottom of the seating part  310 , and the machining, examination, and welding integral device  200  for a nozzle is positioned in front of the inlet of the nozzle  110  to be serviced by using the rotating plate  330 . 
         [0048]    Further, the machining, examination, and welding integral device  200  for a nozzle is inserted into the nozzle  110  to be serviced by using the shaft driver  340  coupled to the seating part  310 . 
         [0049]    Hereinafter, a driving method of the machining, examination, and welding integral device  200  for a nozzle which is disposed in the nozzle  110  will be described. 
         [0050]    As illustrated in  FIGS. 5 and 6 , the machining, examination, and welding integral device  200  for a nozzle which is inserted into the nozzle  110  is positioned in a service part in the nozzle  110  and the support stand  232  of the support member  230  provided in the machining, examination, and welding integral device  200  for a nozzle is attached and strongly supported onto the inner wall of the nozzle  110 . 
         [0051]    An operator checks a defective part of the junction part  120  in the nozzle  110  by driving the examination unit  244  with the first control unit (not illustrated) and when the examination is completed, the service space is isolated from the service-out space by expanding the foreign substance preventing layer  220  so as to prevent the foreign substances generated in machining and welding from flowing out to the outside of the service space. 
         [0052]    By isolating the service space by expanding the foreign substance preventing layer  220 , the service space is maintained in a completely dry state by supplying compressed air to the inside of the service space outside while making water to flow into the service space and from the service space. 
         [0053]    Thereafter, a part of an existing welding part which was welded to the junction part  120  is removed by actuating the machining unit  246  and the foreign substances generated in this case are vacuum-suctioned through the chip collector  248  to be removed. 
         [0054]    Welding is performed in the processed junction part with alloy 52 filler metal by using the welding unit  242  and finishing machining is performed while the part of the junction part  120  welded by using the machining unit  246  is checkable. 
         [0055]    When the machining is completed, water is filled in the service space by contracting the foreign substance preventing layer  220  and a state of the serviced junction part  120  is verified by using the examination unit  244 . When the serviced junction part  120  is not defective, the conveyance positioner  300  and the machining, examination, and welding integral device  200  for a nozzle are removed from the inside of the reactor vessel  110  after the machining, examination, and welding integral device  200  for a nozzle is drawn out from the inside of the nozzle  110  by using the conveyance positioner  300 . 
         [0056]    As described above, in the machining, examination, and welding integral device  200  for a nozzle according to the exemplary embodiment of the present invention, the machining device, the examination device, and the welding device are integrally provided in the housing and the operator controls the machining device, the examination device, and the welding device to perform operations through the control unit according to a required process, and as a result, since the operator does not replace the devices required according to the processes by hand, the devices required according to the processes are operable at the same operating position. 
         [0057]    Further, since the operator does not perform the operation in a zone polluted by radioactivity by performing the operation by moving the machining, examination, and welding integral device for a nozzle into the nozzle in the reactor vessel with the conveyance positioner, a safe operation is performed. 
         [0058]    As described above, although the machining, examination, and welding integral device for a nozzle according to the exemplary embodiment of the present invention has been described, it is obvious to the person skilled in the art that modification, changes, and various modified exemplary embodiments can be made within the scope without departing from the spirit of the present invention.