JPH0122160Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field to which the invention pertains) This invention is a new seal plug that is carried into the reactor through a fuel transfer route that spans the inside and outside of the reactor for a pressure tube nuclear reactor, or a new seal plug that is carried out of the reactor. The present invention relates to a seal plug transfer and handling device for protecting and smoothly transferring used seal plugs.

(Prior Art and its Problems) As is well known, in the pressure tube type nuclear reactor described above, a seal plug that forms a pressure boundary for the primary coolant is attached to the open end of the pressure tube constituting the reactor core. Such a seal plug has a structure that includes a bore latch mechanism that connects to the pressure pipe, and a sealing element that is pressed from the outer periphery of the plug body toward the wall of the pressure pipe. Attaches and detaches by operating the fuel exchanger's grab.
Insertion and removal are performed. In addition, the spent seal plugs pulled out from the pressure pipes are temporarily stored in the magazine of the fuel exchanger, and then transferred from the fuel exchanger to the end of the fuel transfer route that spans the inside and outside of the reactor, and then transported out of the reactor through this transfer route. be done. On the other hand, a new seal plug brought in from outside the furnace is carried through the same transfer route to the end inside the furnace, where it is delivered to a fuel exchanger and then loaded into the pressure pipe. In this case, the conventional transfer method handles the seal plug alone and transfers it naked during transfer.

On the other hand, to explain the mechanism of the seal plug in more detail, the seal element, for example, a metal seal ring attached to the outer periphery of the seal plug,
The sealing element is constantly urged outward via a spring-loaded seal dome provided in the plug body, so that the sealing element protrudes radially from the outer periphery of the plug body and comes into pressure contact with the pressure pipe, so that both We are doing a seal between the two. On the other hand, when inserting a seal plug into or pulling it out from a pressure pipe, first connect the fuel exchanger's glug to the seal plug, then operate the grab to release the restraint of the seal element and move the seal element to the plug body. Insertion and withdrawal are performed with the rod retracted back into the outer diameter.
This prevents the sealing element from sliding unnecessarily against the wall surface of the pressure pipe and causing damage, and allows smooth insertion and withdrawal of the seal plug. By the way, as is clear from the above, when the seal plug is connected to the grab of the fuel exchanger, the sealing element can be retracted into the diameter of the plug body, but when it is in a free state separated from the fuel exchanger, the spring Under bias, the sealing element projects outwardly from the outer periphery of the plug body. For this reason, if the seal plug is transferred alone along the fuel transfer route, the seal element protruding from the outer periphery of the plug body may be damaged by rubbing against the wall surface of the transfer port etc. that makes up the transfer route during transfer. In addition, there are cases where the paper gets caught in the middle of the transfer route and causes problems such as stuck, so some kind of countermeasure is desired.

(Purpose of the invention) This invention was made in consideration of the above points, and it solves the problems such as damage to the sealing element caused by the conventional transfer method, and makes it possible to safely protect the seal plug and transfer it smoothly. The object of the present invention is to provide a seal plug transfer and handling device.

(Main points of the invention) In order to achieve the above object, this invention provides a protective seal plug housing tube that is combined with the latch mechanism of the seal plug to house and hold the seal plug, and the seal plug is housed in this. At the same time, a holding mechanism for holding the seal plug accommodating cylinder in that position is installed at the end of the transfer route inside the furnace, and the holding mechanism holds the seal plug accommodating cylinder. In this system, the seal plug can be transferred by grabbing the fuel exchanger.

(Embodiments of the invention) This invention will be described in detail below based on illustrated embodiments.

Figure 1 shows the overall configuration of a pressure tube nuclear reactor including the fuel transfer route, Figure 2 shows how the seal plug is attached to the pressure tube, and Figure 3 shows the detailed structure of an embodiment of this invention. . First, in FIG. 1, 1 is a reactor containment vessel, 2 is a fuel storage pool of a fuel handling auxiliary building, 3 is a reactor core, 4 is a fuel exchanger running below the core 3, and 5 is a fuel exchange pool. In addition, the fuel transfer route spanning the inside and outside of the reactor includes a transfer port 6 that is piped to penetrate the bottom wall of the fuel exchange pool 5 and face the fuel exchange chamber, and a transfer port 6 that connects the fuel exchange pool 5 to the fuel storage pool 2 outside the reactor. It is composed of a diagonal type transfer chute 7, etc., which are piped across the space. In addition, 8 is the fuel inlet/outlet machine,
9 is a fuel transfer machine. On the other hand, the pressure pipes 10 constituting the reactor core 3 are loaded with fuel assemblies, shield plugs, and seal plugs, and the loading state of the seal plugs in particular is shown in FIG. 2. In FIG. 2, reference numeral 11 denotes a seal plug, which is connected to the pressure pipe 10 via a latch mechanism whose details will be described later, and a seal element 12 attached to the outer periphery of the plug body is in pressure contact with the wall of the pressure pipe 10. The pressure boundary of the primary coolant inside the pipe is formed by sealing.

By the way, with this invention, a seal plug accommodating cylinder is prepared which is transferred by the fuel inlet/output machine 8 on the fuel transfer route shown in FIG. At the lower end of the transfer port 6, which is opened at the same time, there is installed a seal plug container holding mechanism indicated by reference numeral 13 for transferring the seal plug to and from the fuel exchange machine. Next, the detailed structure of these is shown in FIG. First, in the seal plug 11, a seal element 12 serving as the metal seal ring described above is attached to the outer peripheral edge of the tip of a plug body 14, and the plug body 11 is placed opposite to this seal element 12.
4 is provided with a shield dome 16 biased by a compression spring. Further, the lower part of the plug body 14 is equipped with a ball 17 for fixing the pressure pipe, a ball latch mechanism consisting of an actuator 18, and a stem 19 facing the connecting shaft of the shield dome 16. On the other hand, the glove 20 of the fuel exchanger that handles the seal plug 11 includes a dome push-up stem 21 for pushing up the stem 19 of the seal plug to release the seal element, a ball 22 for fixing the seal plug, and a ball for connecting the latch mechanism. 23, and a latch attachment/detachment actuator 24 holding these balls. Next, the structure of the seal plug accommodating cylinder 25 will be described. The seal plug accommodating cylinder 25 has a handling head 27 at the top of a cylindrical body 26 with an open bottom, and a latch ball 1 of the seal plug 11 on the inner peripheral wall surface of the cylindrical body 26.
A stepped portion 30 is formed which engages with the ball groove 28 that connects with the outer peripheral stepped portion 29 of the seal plug 11 and serves as a stopper. Furthermore, the holding mechanism 13 for the seal plug housing cylinder described above includes a fixed support base 31 that protrudes from the inner circumferential wall of the transfer port 6, a movable support plate 32 that moves in and out from the side of the transfer port toward the top surface of the housing cylinder 11, and It is composed of a hydraulic cylinder 33 for driving the movable support plate.

Next, the transfer and handling operation of the seal plug with the above configuration will be described. First, when carrying a new seal plug into the furnace, the seal plug 11 is previously housed and held in the seal plug housing tube 25 outside the furnace, and the housing tube 25 is transferred along the fuel transfer route. Then, when the storage cylinder 25 is suspended through the transfer port 6 by the fuel inlet/output machine and lands on the support stand 31, the hydraulic cylinder 33 is operated to push out the movable support plate 32, and the storage cylinder 25 is lifted from above and below. Hold it in that position.
Next, the fuel exchanger 4 is moved directly below the transfer port 6, the grab 20 is raised to connect it with the seal plug 11, and in this state, the dome push-up stem 21 is driven to move the seal dome 16 to the seal element 1.
2 to release the restraint of the sealing element, and return the sealing element 12 to the inner side of the outer diameter of the plug body 26. In this case, the operating force applied from the glove 20 is carried by the movable support plate 32 via the stepped portion 30 of the housing cylinder 25. Next, the latch actuator 24 of the grab 20 is operated to raise the seal plug actuator 18,
The ball 17 of the latch mechanism is dropped into the ball groove of the actuator 18, and the connection with the housing cylinder 25 is released. Next, the glove 20 is lowered into the fuel exchanger while maintaining the state of connection with the seal plug 11, and the seal plug 11 is pulled out from the housing tube 25 and stored in the magazine of the fuel exchanger. Thereafter, the refueling machine is moved to the core position shown in FIG. 1, and the seal plug 11 is loaded into the pressure pipe 8 of the core. On the other hand, when carrying out the used seal plug pulled out from the furnace, the procedure is reversed to the above, and the seal is placed in advance in the storage cylinder 25, which is supported by the holding mechanism on the transfer port 6 side and is waiting. Plug 1
1 is accommodated and held, and then transferred and carried out of the furnace together with the storage cylinder 25 through a transfer route.

(Effect of the invention) As is clear from the above explanation, according to this invention, the seal plug is not moved naked on the transfer route, but is stored in a protective seal plug storage tube prepared in advance and transferred. Therefore, the sealing element protruding from the plug body of the seal plug to the outer periphery will not be damaged by sliding, massaging, etc.
Furthermore, there is no fear that the sealing element will get caught on structures on the transport route and become stuck, allowing for smooth transport.
Moreover, by providing a holding mechanism for the seal plug housing cylinder at the end of the inside of the furnace on the transfer route, it is possible to securely transfer the seal plug between the fuel exchanger and the seal plug housing cylinder by using a grab operation. Effects can be obtained.

[Brief explanation of the drawing]

Figure 1 shows the configuration of the entire pressure tube nuclear reactor facility, Figure 2 shows how seal plugs are loaded into the pressure tubes of the reactor core in Figure 1, and Figure 3 shows the detailed structure of an embodiment of this invention. It is a configuration sectional view. DESCRIPTION OF SYMBOLS 1... Reactor containment vessel, 2... Ex-core fuel storage pool, 3... Reactor core, 4... Fuel exchange machine, 6... Transfer port constituting a transfer route, 10... Pressure pipe, 11... Seal plug, 12... Seal element, 13... Seal plug housing cylinder holding mechanism, 2
0... Glove of fuel exchanger, 25... Seal plug housing tube, 26... Cylindrical body, 27... Handling head, 28... Ball groove as a latch connection part.

Claims (1)

[Scope of utility model registration request] This is a transfer and handling device for new seal plugs carried into a nuclear reactor from outside the reactor or used seal plugs carried out from inside the reactor. a seal plug housing cylinder having a connecting portion formed on the peripheral wall surface to engage with a latch mechanism of the seal plug;
and a holding mechanism for the seal plug accommodating cylinder installed at the inner end of the fuel transfer route extending between the inside and outside of the furnace; The pressure tube type atom is characterized in that the seal plug is transferred between the fuel exchanger and the seal plug housing tube while the seal plug housing tube is held at the terminal end of the transfer route by the holding mechanism. Furnace seal plug transfer handling device.