JPH0159555B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in light water cooled nuclear reactors.

Conventionally, in this type of nuclear reactor, the lid is supported in a space within the containment vessel and is attached to a lid that is fastened to the upper opening of the reactor vessel in which the core structure is built. A large number of vertically extending control rod drive devices are arranged in a row, and a ring-shaped duct for cooling the drive devices is provided on the lid to surround the drive devices and is manufactured separately from the lid. In addition, tie rods are disposed between seismic supports supporting each of the drive units and cavities within the containment vessel to protect the control rod drives against heat and seismic forces.

Thus, the reactor vessel lid is opened annually for fuel changes and periodic inspections. This lid release work is performed by loosening and loosening the stud bolts for fastening the lid to the reactor vessel, and by disconnecting the connecting member from the fixed bed inside the containment vessel. Since the duct is located close to the stud bolt, one must first begin by disassembling the ring-shaped duct. Furthermore, since conventionally a disassembleable cable tray is used, the cables are first wound up and then the cable tray is moved, which is dangerous overhead work, so the duct must be disassembled during this time. No,
Waiting time increases significantly. Furthermore, the removal work of the tie rods for supporting the seismic support involves dangerous work involving handling heavy objects due to poor footing, and furthermore, the work on the lid increases the amount of radiation exposure as the required time increases. It is something to do.

Furthermore, in the conventional system mentioned above, the tie rods that support the seismic support are disassembled when the lid is opened, making the seismic support unstable and making it difficult to rebuild each part when the lid is returned to its previous position in order to resume reactor operation. Adjustments must be made, and this adjustment work is also extremely difficult.

The present invention has been proposed in order to eliminate such drawbacks, and includes a reactor vessel that is supported in a space within the containment vessel and has a core structure built therein, and a reactor vessel that is fastened to the upper end opening of the vessel. a control rod drive device that extends vertically through the cover, and a double cylindrical control rod drive cooling duct that surrounds the drive device and is erected integrally with the control rod drive device on the cover. ,
The present invention relates to a light water-cooled nuclear reactor, characterized in that the light water-cooled nuclear reactor is constructed of an earthquake-resistant member disposed inside the duct and horizontally supporting the drive device.

In the present invention, as described above, the cooling duct for the control rod drive device, which surrounds the control rod drive device that is erected integrally with the lid of the reactor vessel and extends vertically on the lid, has a double cylindrical shape. Since the duct is formed as a duct, the duct has high strength and rigidity, and functions as a cooling duct for the control rod drive device as well as an earthquake-resistant support for the control rod drive device. Furthermore, an earthquake-resistant member that horizontally supports the control rod drive device is disposed inside the duct, so that the seismic horizontal force applied to the control rod drive device is supported by the duct via the earthquake-resistant member. It is something.

In addition, in the present invention, since the duct has a stable structure that is erected integrally with the reactor vessel lid, even if the lid is lifted or moved during the lid opening operation, the equipment on the lid can be easily removed. , there is no deviation in the relative position of the members, there is no need for any position adjustment work after restoration, and the tie rod is for intermediate seismic support of the control rod drive device, which is dangerous like the conventional type mentioned above, which has poor footing and handles heavy objects. This eliminates the need for separation work. Furthermore, as mentioned above, since the cooling duct of the control rod drive device and the lid of the reactor vessel have an integral structure, the connection duct to the cooling duct or the point where the power cable needs to be disconnected can be connected to the integral structure. By concentrating the cooling ducts on the upper floor of the cooling duct, it is possible to almost eliminate waiting time, shorten working time, improve work safety, and reduce the amount of radiation exposure of workers. The present invention has many advantages.

The present invention will be described below with reference to the illustrated embodiments.

Reference numeral 1 denotes a reactor vessel which is supported in a space within a reinforced concrete containment vessel 2 and has a reactor core structure 3 built therein, and a reactor vessel lid 4 is fastened to its upper opening via stud bolts 5.

A plurality of travel housings 6 are hermetically penetrated through the lid 4 so as to extend vertically, and each housing 6 is provided with a control rod 7 that controls a control rod 7 that moves up and down within the housing 6 and the reactor vessel 1. A rod drive device 8 is mounted.

9 is a cooling duct for the control rod drive device 8;
It is formed into a double cylindrical shape with an inner wall plate and an outer wall plate stretched on both the inner and outer peripheral surfaces of a support made of H-shaped steel etc. arranged at predetermined intervals on a concentric circumference, and a predetermined It is integrally connected to the lid 4 through a connecting portion 10 formed by connecting brackets protruding at intervals and brackets protruding at corresponding positions on the lid 4 with pins. , and are erected so as to surround the control drive device 8 standing on the lid 4. The duct 9 has a cooling air suction window 11 in its lower part, and its upper part is formed into a ring-shaped part 9a that bulges out to the outer periphery. , external duct 1
2 are connected to each other, and an upper seismic support tie rod 13 is detachably connected between the container 2 and the inner wall thereof. Reference numerals 14 and 15 are earthquake-resistant plates, respectively, which have passages for the travel housing 6 and the power cable 16 of the control rod drive device 8, as well as cooling air ventilation holes, and are rigidly attached to the inner plate of the duct 9. It is connected to a fixed annular frame (not shown), so that the seismic horizontal force applied to the control rod drive device 8 is supported by the duct 9 via the seismic plates 14 and 15. A hoist 17 for lifting and lowering the stud bolt tightening device for attaching and detaching the stud bolt 5 for fastening the lid 4 to the reactor vessel 1 and its annular guide rail 18 are attached to the lower surface of the ring-shaped portion 9a.

Reference numeral 19 denotes an intermediate connector panel that collectively supports the connection terminals of the power cables 16, and is arranged on the duct 9 as shown in FIG. 2 or on the work floor of the containment vessel 2 as shown in FIG. It is attached to the cable tray 20.

The cable tray 20 is rotatably supported 21 on the work floor, and when the lid 4 is opened, a wire rope 22 connected to the tip of the cable tray 20 is attached to the inner wall of the containment vessel 2 as shown in FIG. The wire rope 22 may be pulled up by a winch or an overhead crane, or the extension of the rotation pin of the cable tray pivot portion 21 may be rotated by an appropriate power. Note that since the ceiling crane is used not only for raising the cable tray but also for lifting heavy objects inside the reactor building, there is no need to provide extra equipment for the cable tray. However, if the time required to occupy the crane is a problem, a dedicated winch or the like is used.

When the intermediate connector panel 19 is placed on the duct 9 side, the connection terminals are disconnected on the duct, and when the intermediate connector panel 19 is placed on the cable tray 20 side, the disconnection work is performed from the tray side. When considering the stability of the structure and the risk of falling, it is preferable to arrange the intermediate connector panel 19 on the tray side. However, the type and arrangement of the connector,
Alternatively, depending on how the cable is handled, it is not necessarily necessary to provide it on the tray side.

Since the illustrated embodiment is constructed as described above, the external duct 12 and tie rod 7 are removed, the connector is separated from the intermediate connector panel 19, the cable tray 20 is raised, and the lid 4 is opened. The stud bolts 5 are unfastened to the reactor vessel 1, and the lid 4 is pulled up using a ceiling crane.

At this time, since the protection device for the control rod drive device 8 consisting of the duct 9 and seismic plates 14 and 15 is attached as an integral structure on the lid 4, it is necessary to disconnect the external duct or power cable as described above. By consolidating the parts on the upper floor of the duct 9, it is possible to shorten the working time and reduce the radiation dose during working.

The restoration work is carried out in the reverse order, but since the protective device is mounted as a rigid integral structure on the lid, no relative movement of the equipment occurs and readjustment work is not necessary.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various ways without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of a light water-cooled nuclear reactor according to the present invention, FIGS. 2 and 3 are side views showing respective embodiments of the mounting portion of the cable tray and the intermediate connector panel, FIG. 4 is a side view of the upright portion of the cable tray. 1...Reactor vessel, 2...Reactor containment vessel, 3
... Core structure section, 4 ... Lid, 5 ... Stud bolt, 8 ... Control rod drive device, 9 ... Control rod drive device cooling duct, 14, 15 ... Earthquake-resistant plate.

Claims (1)

[Claims] 1. A reactor vessel supported in a space within the containment vessel and containing a reactor core structure, a lid fastened to the upper opening of the vessel, a control rod drive device extending vertically through the lid, A double cylindrical control rod drive device cooling duct surrounds the drive device and is erected integrally with it on the lid, and is disposed inside the duct to support the drive device in the horizontal direction. A light water-cooled nuclear reactor characterized by being constructed from earthquake-resistant materials.