RU2449390C1 - Track of process channel of nuclear uranium-graphite reactor - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: invention relates to facilities for recovery of serviceability of a temperature compensator in a nuclear uranium-graphite reactor process channel (PC) track temperature compensator and may be used to do major overhauls of the reactor. The track of the process channel of the nuclear uranium-graphite reactor is formed with a telescopic connection of the inner and outer pipe. On the outer pipe there is an extension made in the form of a band yoke protruding above its end part.

EFFECT: invention makes it possible to recover compensating ability of a unit of telescopic connection of tracks without withdrawal of a process channel to ensure the power unit operation during the extended service life.

3 cl, 6 dwg

Description

The proposed technical solution relates to the operation technique of nuclear reactors, in particular, to the means of restoring the operability of the temperature compensator of the path of the technological channel (TC) of a nuclear uranium-graphite reactor, and can be used for overhauls at the reactor.

During operation of a nuclear uranium-graphite reactor, as a result of radiation-thermal effects, volumetric radiation shrinkage occurs in graphite blocks, which leads to a significant reduction in the geometric dimensions of the reactor core. According to the results of the control conducted at the Leningrad NPP, a decrease in the linear height dimension of the columns of the graphite masonry of the reactor was established. In nuclear uranium-graphite reactors, a structural unit is provided that performs the function of a temperature compensator. The temperature compensator is made in the form of a telescopic connection of the upper pipe path and the connecting pipe. The working stroke of the temperature compensator is 220 mm. The specified parameter is one of the main criteria that determine the duration of operation of reactors. Radiation shrinkage of masonry by an amount corresponding to the working stroke of the temperature compensator or more is not permissible, because will lead to a violation of the alignment of the upper pipe path and the channel of the column graphite masonry reactor. In the prior art discovered patents of the Russian Federation relating to the means of restoring the operability of the telescopic connection of the path of the technological channel. In the patent of the Russian Federation No. 2075117, in the gap between the base plate of the column of graphite blocks and the glass formed after raising the graphite masonry with an expanding rod, support segment inserts are installed, onto which the column of graphite blocks is then lowered. In the patent of the Russian Federation No. 2117340, the design of the most segmented support insert and a device for its installation are described. The above patents solve the problem of restoring the operability of the telescopic connection of the technological channel path.

The closest analogue of the claimed invention is a patent of the Russian Federation No. 2105358. In this patent, as a means for restoring the operability of the path of the technological channel made of two telescopically connected pipes, segmented inserts with characteristic transverse dimensions smaller than the diameter of the channel of the graphite masonry are used, which are installed between the protective plate and the graphite masonry. The installation of segmented inserts is performed after the dismantling of the technological channel.

The disadvantage of the technical solution presented in the closest analogue is that for the implementation of this technical solution requires a large amount of prepared work (dismantling the technological channel), the complexity and duration of the work. To perform the work, it is necessary to manufacture expensive unique devices and equipment.

The problem solved by the claimed invention is to create a technical solution that allows you to perform work to restore the operability of the telescopic path connection (TST) without removing (replacing) the TC and in a shorter time.

The essence of this technical solution consists in the fact that in the path of the technological channel of a nuclear uranium-graphite reactor formed by telescoping the inner and outer tubes, it is proposed to fix an extension cord made in the form of a retaining collar protruding above its end part on the outer tube. In addition, it was proposed to provide the retaining clamp with a hinge and a latch, and take the height of the protruding part of the extension cord above the end outer pipe to be equal to 70 ÷ 80 mm.

The extension of the path of the technological channel is carried out without removing the technological channel. No special expensive equipment is required to perform work on the vertical movement of the protective plate in order to form a gap between the protective plate and graphite masonry. An extension cord in the form of a clamp is installed using a manipulator. The presence of a hinge and a clamp in the retaining clamp allows you to securely fix the bandage on the outer pipe. The accepted height of the protruding part of the clamp ensures reliable operation of the telescopic connection until the reactor is decommissioned.

An example of the path of the technological channel of a nuclear uranium-graphite reactor is shown in FIGS. 1, 2, 3, 4, 5, 6, where FIGS. 1 and 2 schematically show the paths of the technological channels. In Fig.1 - the pipe path enters the inside of the connecting pipe, and Fig.2 shows an option when, on the contrary, the connecting pipe enters the inside of the tubing. Figure 3 is a front view of the path extension according to the embodiment shown in figure 1. Figure 4 shows a top view of the extension of the path for the variant depicted in figure 1 (section along BB). Figure 5, 6 shows a front and top view (section BB) of the path extension for the embodiment shown in figure 2.

The path of the technological channel consists of a pipe path 1, fixed in the upper metal structure 2, a connecting pipe 3, mounted on a protective plate 4. The TST node of the uranium-graphite reactor tract has structurally two designs. In one design (Fig. 1), the pipe path 1 enters the connecting pipe 3, in another design (Fig. 2) the connecting pipe 3 enters the pipe 1. Depending on the design of the TST assembly, the extension pipe 6 is either installed on the connecting pipe 3 ( figure 1), or on the pipe path 1 (figure 2). The presented graphic material of FIGS. 1 and 2 and the description thereto illustrate essentially the same technical solution: the path of the technological channel of a nuclear reactor of a uranium-graphite reactor formed by two telescopically connected pipes, which are called a tubular path in the description text and on the graphic material 1 and a connecting pipe 3. The extension of the path 6 (Fig.3, 4) is made in the form of two half-cylinders 5 (Fig.4, 6) with flanges provided with a hinge 7 and coupling bolts 8.

The installation of the path extension is as follows. On the plateau of the reactor near the penetration, a special loading device is mounted in the reactor, onto which a delivery robot is installed (not shown in Fig. 2). A robot installer is installed on the delivery robot with a path extension attached to it. The loading device through the penetration into the reactor lowers the delivery robot into the reactor space on the heat shield metal structures. The delivery robot moves off the loading device platform and, together with the installation robot and the path extension 6, moves around the reactor to the desired operating zone. A robot installer (not shown in FIG. 2) is separated from the delivery robot with a path extension 6 and, moving along the upper metal structure of the magnetically suspended reactor, delivers a path extension to the path. Using the manipulators of the installation robot, an extension cord is mounted on path 6. The installation robot returns to the delivery robot and is fixed on it. The delivery robot with the installation robot moves to the boot device and enters its platform. The loading device is lifted by the delivery robot with the installation robot installed on it from the reactor space to the reactor plateau. A new extension of the path is fixed on the installation robot, and the installation cycle is repeated for the next path.

The proposed method allows to restore the compensating ability of the node telescopic connection of paths without removing (replacing) the technological channel to ensure the operation of the power unit during the extended period of operation.

Claims (3)

1. The path of the technological channel of a nuclear uranium-graphite reactor, formed by a telescopic connection of the inner and outer tubes, characterized in that the extension tube is fixed on the outer tube, made in the form of a retaining collar protruding above its end part. 2. The path of the technological channel of a nuclear uranium-graphite reactor according to claim 1, characterized in that the retaining clamp contains a hinge and a latch. 3. The path of the technological channel of a nuclear uranium-graphite reactor according to claim 1, characterized in that the extension cord projects 7080 mm above the end part of the outer pipe.

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