JPH0464039B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to high-pressure and low-pressure turbines directly driven by radioactive steam generated in a nuclear reactor, cross-around pipes provided between these turbines, and moisture separation. The present invention relates to a shielding structure for a nuclear power turbine suitable for preventing the diffusion of radioactivity from a reactor, a combination intermediate valve, a steam introduction pipe, etc.

[Background of the invention]

Compared to thermal power plants, nuclear power plants use steam with a large specific volume at low temperature and low pressure.
The equipment itself has a large capacity, and a protective wall is required to effectively prevent the spread of radioactivity, resulting in a huge construction cost. Therefore, it is extremely necessary to rationally arrange the above-mentioned equipment and to effectively structure and arrange the protective walls.

In the models shown in Figures 1 to 3, auxiliary equipment installed between the high-pressure turbine and the low-pressure turbine placed on the floor is mainly located in a room surrounded by a thick concrete protective wall below the floor. The structure shown in FIGS. 4 and 5 has the above-mentioned auxiliary equipment arranged more rationally. That is,
In FIGS. 4 and 5, a high-pressure turbine 3 and a low-pressure turbine 4 are arranged on the same floor as the building floor 2.
G frame). In addition, a moisture separator 9 for separating moisture in steam, a combination intermediate valve 5 (hereinafter referred to as CIV), a cross-around pipe 8 connecting these, and a steam inlet connecting the CIV and the low-pressure turbine 4. A pipe 20 is also provided on the building floor 2. Among the above-mentioned devices, the steam in the low-pressure turbine 4 is low-temperature and vacuum exhaust steam, so the influence of radioactivity diffusion is small, but the other devices require prevention of radioactivity diffusion. The moisture separator 9, cross-around pipe 8, CIV, etc. are covered by a box-shaped shielding wall 14 that stands up from the building floor 2, but as shown in the figure, there is a steam inlet pipe on the low-pressure turbine 4 side of the shielding wall 14. An opening 21 is formed through which 20 passes. Therefore, a problem arises in that radioactivity is diffused from this opening 21. In order to prevent this, a skyshear inshield method is adopted in which the high-pressure and low-pressure turbines 3 and 4, the moisture separator 9, etc. are covered in a large area as a whole, but this method results in an extremely heavy structure, resulting in high costs. This results in the disadvantage that the ease of maintenance and inspection of each piece of equipment becomes poor.

That is, in FIGS. 1 and 2, the building 22 is partitioned by a building floor 2 placed in the middle, and the lower floor surface of the building floor 2 is surrounded by a thick concrete wall to prevent radiation diffusion. A valid room is formed. Since the height of the building needs to be increased above the building floor 2, it is difficult to increase the thickness of the side walls and ceiling due to the architectural structure. Therefore, a structure is adopted in which the auxiliary equipment, which is likely to spread radioactivity, is placed in a room below the floor. That is, high pressure turbine 3, low pressure turbine 4, generator 6 and exciter 7
are arranged in series on the T-G frame 1 which is on the same level as the building floor 2.

As shown in FIG. 2, the exhaust steam from the high-pressure turbine 3 passes through the cross-around pipe 8 placed under the T-G frame 1, enters the moisture separator 9, dehumidifies it, and then penetrates the building floor 2. A second cross-around tube 8 passing through the drilled opening 10 (also shown in FIG. 3)
and enters CIV5, which is located on floor 2 of the building. Furthermore, the steam is introduced into the low pressure turbine 4 from the CIV 5 through the steam introduction pipe 20 connecting it. In addition, CIV
5 is supported by a support 23 attached to the T-G frame 1.

Also, the reactor feed water pump and drive turbine 11
Although the degree of radioactivity diffusion is large, two units will be installed on the building floor 2 due to the arrangement of equipment. The reactor feed water pump and drive turbine 11 are surrounded by a thick concrete shielding wall 13 to prevent radioactivity from spreading. Furthermore, the high-pressure turbine 3, CIV, and steam introduction pipe 20 are covered with shield plates 12 and 19, respectively, to prevent radioactivity from spreading.

What is shown in FIGS. 4 and 5 shows the configuration of the prior art in which the arrangement of the above-mentioned devices is made more rational, and the reduction in construction cost and the prevention of radiation diffusion are more effectively considered. In this case, the moisture separator 9,
The CIV 5, the cross-around pipe 8 that connects the CIV with the moisture separator 9, and the steam introduction pipe 20 are arranged on the upper surface of the building floor 2, and conversely, although not shown, the reactor feed water pump and the drive turbine 11 are installed on the floor. It is placed under the surface. A box-shaped shielding wall 14 with a ceiling 16 is integrally formed on the building floor 2 and is erected, and includes a moisture separator 9, a cross-around pipe 8, and a CIV.
5 is covered by a shielding wall 14. However, since the steam introduction pipe 20 is installed across the CIV 5 and the low pressure turbine 4, an opening 21 through which the steam introduction pipe 20 can pass is formed on the low pressure turbine 4 side of the shielding wall 14. Therefore, a problem arises in that radioactivity is diffused from this opening 21. Therefore, as a means to prevent this, the skyshear inshield method, which covers all the equipment on the building floor 2 as described above, is adopted, but this method has the drawbacks of high cost and poor maintenance and inspection performance. arise.

[Purpose of the invention]

The present invention was devised to eliminate the above-mentioned drawbacks, etc., and its purpose is to reliably prevent the spread of radioactivity, facilitate maintenance and inspection of each equipment, and provide a simple and inexpensive nuclear power source. The object of the present invention is to provide a shielding structure for a turbine.

[Summary of the invention]

That is, the present invention provides high-pressure and low-pressure turbines that are directly driven by radioactive steam generated in a nuclear reactor, and a cross that is disposed on the same floor as these turbines and that guides the steam from the high-pressure turbine to the low-pressure turbine. The around pipe and the moisture separator interposed therebetween are also arranged on the same floor surface, and one end thereof is combined with the above-mentioned cross-around pipe and connected via an intermediate valve, and the other end is a steam introduction pipe that connects to the low-pressure turbine; and a steam introduction pipe that is erected on the floor surface and covers the moisture separator, cross-around pipe, and combination intermediate valve, and is connected to the low-pressure turbine side. a box-shaped shielding wall forming a penetrating opening; and a box-shaped shielding wall that is removably engaged with the box-shaped shielding wall to close the opening and the steam introduction pipe. a shield plate formed to have a contact portion in close contact with the low-pressure turbine; and a shield plate disposed so as to cover the steam introduction pipe between the shield plate and the low-pressure turbine, and the end contact portion thereof In order to achieve the desired purpose, the low pressure turbine is provided with a shielding plate which is formed to be in close contact with the shield plate and the low pressure turbine, and which is detachably formed.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings.

First, an overview of this embodiment will be explained.

As shown in FIG. 7, a shield plate 17 is provided at an opening 21 of a box-shaped shielding wall 14 that encloses a moisture separator 9 and the like disposed on the building floor 2. . This shield plate 17 prevents the diffusion of radioactivity from the CIV5 etc. housed within the shield wall 14. Furthermore, since the steam introduction pipe 20 remains exposed, it is covered with the shielding plate 18.

The above prevents the spread of radioactivity.

Next, this embodiment will be explained in more detail.

In FIGS. 6 and 7, the high pressure turbine 3
The low-pressure turbine 4, generator 6, and exciter 7 are placed on the T-G mount 1, and the moisture separator 9, cross-around pipe 8, CIV 5, and steam introduction pipe 20 are placed on the same surface as the TG mount 1. It is placed on floor 2 of a certain building.
The shielding wall 14 is formed integrally with the building floor 2 and is erected from this, is formed in a box shape, and has a ceiling 1 on the upper side.
6 is integrally formed. This box-shaped shielding wall 14
Inside, there is a moisture separator 9, a cross-around pipe 8,
CIV5 is stored and radioactivity is prevented from spreading. Note that the moisture separator 9 is suspended by a support 15 hanging from the ceiling 16.

On the other hand, since the steam introduction pipe 20 connects the CIV 5 and the low-pressure turbine 4, an opening 21 is formed in the shielding wall 14 to penetrate the steam introduction pipe 20. A shield plate 17 is provided to close this opening 21. The shield plate 17 has a thickness of 100 mm to 200 mm.
It is formed from a steel plate of mm and is removably engaged with the shielding wall 14. Note that a cutout (not shown) is formed below the shield plate 17 to allow the steam introduction pipe 20 to pass therethrough. Shield plate 17
The contact portions between the shielding wall 14 and the steam introduction pipe 20 are formed so as to be in close contact with each other to prevent radiation diffusion.

Next, on the outer peripheral side of the steam introduction pipe 20, a shielding plate 18 that covers the steam introduction pipe 20 is removably provided.
The contact portions between the shield plate 18, the shield plate 17, and the low-pressure turbine 4 are also formed so as to be in close contact with each other, thereby preventing the diffusion of radioactivity.

Further, the high-pressure turbine 3 is covered with a shielding plate 12 as in the prior art, but the low-pressure turbine 4 is not provided with any shielding means for the above-mentioned reason.

With the above configuration, the high-pressure turbine 3, moisture separator 9, cross-around pipe 8, CIV 5, steam introduction pipe 20, etc., which have a high degree of radioactivity diffusion, are covered with a shielding plate, etc., so radioactivity diffusion can be prevented. It will definitely be implemented. Further, as described above, since the entire structure is not covered with a shielding plate, it can be implemented lightweight and inexpensively. Further, since the low pressure turbine 4 is not covered, it can be easily disassembled and inspected. or,
Since the shielding plate 18 and the shielding plate 17 are formed to be detachable, inspection and maintenance of the CIV 5, the steam introduction pipe 20, etc. are easy.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is possible to reliably prevent the spread of radioactivity, and also to facilitate the maintenance and inspection of each device, which can be carried out easily and at low cost.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a conventional nuclear turbine and the arrangement of each device, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3 is a sectional view taken in the - arrow direction in Fig. 1. , FIG. 4 is a plan view showing a conventional nuclear power turbine employing a rational plant layout and the arrangement of each device, FIG. 5 is a sectional view taken along the - line arrow in FIG. 4, and FIG. Plan view of the embodiment, seventh
The figure is a cross-sectional view taken along the - line arrow in FIG. 6. 1... Turbine and generator mount, (T-G mount), 2... Building floor, 3... High pressure turbine, 4...
...Low pressure turbine, 5...Combination intermediate valve (CIV),
6... Generator, 7... Exciter, 8... Cross-around pipe, 9... Moisture separator, 10, 21... Opening, 11... Reactor feed water pump and drive turbine, 12, 19, 18... Shielding plate, 13, 14
...Blocking wall, 15,23...Support, 16...
Ceiling, 17...shield plate, 20...steam introduction pipe, 22...building.

Claims (1)

[Claims] 1. High-pressure and low-pressure turbines that are directly driven by radioactive steam generated in a nuclear reactor, and a system that is installed on the same floor as these turbines and directs the steam from the high-pressure turbine to the low-pressure turbine. The leading cross-around pipe and the moisture separator interposed in between are also arranged on the same floor surface, and one end thereof is connected to the cross-around pipe through an intermediate valve, and the other is connected to the cross-around pipe through an intermediate valve. a steam introduction pipe whose end side is connected to the low-pressure turbine; and a steam introduction pipe erected on the floor surface, covering the moisture separator, cross-around pipe, and combination intermediate valve, and introducing the steam to the low-pressure turbine side. a box-shaped shielding wall forming an opening through which a pipe penetrates; A shield plate is formed so that a contact portion with the introduction pipe is in close contact with the steam introduction pipe, and the shield plate and the low-pressure turbine are arranged so as to enclose the steam introduction pipe, and the end portion thereof A shielding structure for a nuclear power turbine, comprising: a shielding plate whose contact portions are formed so as to be in close contact with the shielding plate and the low-pressure turbine, respectively, and which are detachably formed.