JPS58158588A - Shielding structure of atomic power turbine building - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radiation shielding structure for a nuclear power turbine building.

Nuclear power plants have lower temperatures than thermal power plants.

Since steam with low pressure and large specific volume is used, the steam motor becomes large and, in addition, protective walls must be installed to prevent the spread of radioactivity, resulting in a large building structure and a huge amount of building construction. Requires cost.

In boiling water nuclear power plants, reactor-generated steam is directly used as driving steam for the steam turbine.
Steam equipment and its auxiliary equipment must be shielded.

Conventionally, auxiliary equipment was generally placed below the operating floor, and the ceiling, floor, and walls of the auxiliary equipment room were made of thick concrete to prevent radiation sources. On the other hand, since it is difficult to shield the main equipment installed on the operating floor from radiation with the walls and ceiling of the building, it is common to surround the main equipment by installing a shielding structure indoors. It is.

The power generation steam turbine, which is the main equipment, is large and heavy, so it is installed on a special frame. In consideration of one change in inspection and maintenance, the high-pressure turbine with high radiation source concentration, the combination intermediate valve, and the steam introduction pipe to the low-pressure turbine are surrounded by a box-shaped shielding structure made of split thick steel plates that can be disassembled and reassembled. .

Fig. 1 shows a plan view of the shielding structure of the conventional nuclear power turbine building mentioned above, and Fig. 2 shows the A-A cross section in Fig. 1, and Fig. 3 shows the B-B cross section in Fig. 3. . The operating floor consists of a turbine generator mount l and a building floor 2. A high-pressure turbine 3 is placed on the above-mentioned turbine generator mount 1,
A low pressure turbine 4°4.4, a generator 6 and an exciter 7 are installed, and the combination intermediate valve 5 is arranged near the turbine generator mount l as shown in FIG. Supported by Kirel.

The exhaust steam of the high-pressure turbine 3 is transferred to a cross-around pipe 8 (Fig. 2) installed under the operating floor and a combination intermediate valve 5.
(Fig. 3) and is supplied to the low pressure turbine 4. 10 is the frontage of the floor surface.

(See FIG. 2) A moisture separator 9 is provided in the middle of the cross-around tube 8. (See FIG. 1) Since the turbine 11 for driving the water supply pump is small and lightweight, it is installed on the building floor 2 and surrounded by a shielding wall 13 made of concrete. 1
2 is a steel plate shielding plate for the high-pressure turbine, and 19 is a steel plate shielding plate for the low-pressure turbine steam introduction pipe 20.

FIG. 4 is a plan view of a known nuclear power turbine building shielding structure that streamlines the above-mentioned nuclear power turbine building shielding structure;
The figure is a sectional view taken along the line CC. In this 3@shield structure, the vi moisture separators 9, 9 are installed on the building floor 2, and the water supply pump driving turbine (not shown) is installed below the building floor 2. Due to this rearrangement, the cross-around tube 8, which is a relatively high concentration radiation source, is also placed on the building floor 2. A shielding wall 14 and a shielding ceiling 16 are installed to cover the cross-around pipe 8, moisture separator 9, combination intermediate valve 5, etc., which are high concentration radiation sources. 15
is a boat.

In the known shielding structure of a nuclear power turbine building shown in FIGS. 4 and 5, the combination intermediate valve 5 is supported by a turbine generator mount l, while the shielding wall 14 is integrated with the building floor 2 by a concrete IJ. - S-shield wall 1
4 alone, it is difficult to completely surround the combination intermediate valve 5, and therefore an auxiliary shielding structure (not shown) is required to shield the combination intermediate valve 5. Adding such auxiliary shielding structures complicates the structure,
Handling, maintenance and maintenance are troublesome.

In order to solve the above problems and obtain a complete shielding effect with a simple shielding structure, a shielding structure for an atomic turtle pin building as shown in FIG. 6 has been invented. Figure 7 shows the D shown in Figure 6.
-D sectional view. As shown in FIG. 7, this shielding structure includes a shielding ceiling 16.
As well as passing a ceiling shield 17 shaped between 16 and 16,
As shown in FIG. 6, a shield 18 in the form of a screen is provided, and although the structure is simple and the laydown space can be reduced, which is an excellent practical effect, it has the following disadvantages.

Components indicated by dotted lines in FIG. 6 mean that they are shielded. As shown in FIGS. 6 and 7, the low pressure turbine 4 is housed in a shielded chamber. Therefore, when performing periodic inspection and maintenance of the low-pressure turbine 4 or daily patrol, inspection and maintenance technicians must enter the high radiation source room. Therefore, the time spent indoors is limited. Also, even for simple disassembly, the shield plate must be removed. In particular, the overhead crane cannot be used unless the ceiling shield 17 is removed.

The present invention has been made in view of the above circumstances, and can completely shield high-concentration radiation sources such as a moisture separator and a combination intermediate valve with a simple configuration. The purpose of the present invention is to provide a shielding structure for a nuclear power turbine building that does not cover the building.

In order to achieve the above object, the present invention provides for a combination intermediate valve to be separated from a turbine generator mount and supported by a building floor, and a combination intermediate valve and a moisture separator to be mounted on the turbine generator mount. It is characterized by being stored in a sleeping room isolated from the public.

Conventionally, the combination intermediate valve was generally installed on the turbine generator mount by shortening the steam introduction pipe (drawing reference number 20 in Figs. 3 to 7) that connects the combination intermediate valve and the low-pressure turbine. This was done in order to reduce the internal volume and prevent acceleration of the turbine due to residual steam when the combination intermediate valve was suddenly closed.According to the inventor's experimental research, the above steam introduction It was found that even if the pipe was slightly lengthened, the turbine acceleration when the intermediate combination valve suddenly closed was small and did not cause any practical problems.
Based on the results of this experimental study, the present invention is improved by separating the intermediate combination valve from the turbine generator mount and shielding it as described above, so that the low pressure turbine is not enclosed in the shielding chamber.

Next, an embodiment of the present invention will be described with reference to FIGS. 8 and 9. Components drawn with dotted lines in FIG. 8 mean that they are housed in a shielded room.

FIG. 9 is a sectional view taken along the line EE shown in FIG. 8.

As can be easily understood by comparing FIG. 7 according to the prior art and FIG. 9 according to the present invention, in the present invention, the combination intermediate valve 5 is slightly spaced apart from the low pressure turbine 4 and is placed on the upper surface of the building floor 2. Support. Along with this, the steam introduction pipe 20 becomes slightly longer, but the combined intermediate valve 5 and low pressure turbine 4
It can be completely partitioned off with a '51 shielding wall 14. The steam introduction pipe 20 is surrounded by a shielding plate 21 . Steam introduction pipe 2, which is one of the relatively high concentration radiation sources, by applying the present invention
0 becomes a little longer, but by covering it with a shield with a simple structure, complete radiation source countermeasures can be easily achieved in practice.

The low-pressure turbine 4 is located outside the above-mentioned shielded room, but the steam inside the low-pressure turbine 4 is exhaust steam with a high degree of vacuum, and the low-pressure turbine itself has a double structure, so as a radiation source countermeasure for the low-pressure turbine. No separate shielding is required.

As shown in FIG. 8, the high pressure turbine 3 is a conventional device (first
4 and 6), the S bottom plate 12
cover with

The shielding structure for a nuclear power turbine according to the present invention has the above configuration, and includes a combination intermediate valve 5 which is a high concentration radiation source,
The moisture separator 9 and the cross-around tube 8 connecting the two are completely enclosed in one shielded room to prevent the spread of radioactivity. In addition, inspection and maintenance of the low-pressure turbine can be performed without entering the shielded room, so there is no severe time constraint. Moreover, when disassembling a low-pressure turbine, an overhead crane can be used without removing the shield. Further, the steam introduction pipe 20, which is one of the high-concentration radiation sources, passes through the shield 14 to the outside of the shielding room, but it can be easily shielded by providing a shield plate 21f exclusively for the steam introduction pipe.

As explained above, the present invention provides a shielding structure for a nuclear power turbine building in which a combined intermediate valve is connected to a turbine generator 11.
Moisture separation can be achieved with a simple configuration by separating the L machine from the mount and supporting it on the building floor, and installing the above combination intermediate valve and moisture separator in a shielded room isolated from the turbine generator. High-concentration radiation sources such as the chamber and the combination intermediate valve can be completely shielded, and since the low-pressure turbine is not covered in the high-radiation source room, there is no risk of impeding its maintainability.

[Brief explanation of drawings]

Figure 1 is a plan view of the shielding structure of a conventional nuclear turbine building, Figure 2 is a cross-sectional view taken along the A-A plane shown in Figure 1, Figure 3 is a cross-sectional view taken along the same <B-8 plane, and Figure 3 is a cross-sectional view taken along the same <B-8 plane. Figure 4 is a plan view of the shielding structure of a conventional nuclear turbine building, which is different from the above.
FIG. 5 is a sectional view taken along the plane C-C shown in FIG. 4, FIG. 6 is a plan view of a shielding structure of a nuclear turbine building according to a prior art different from the above, and FIG. 8 is a plan view of the shielding structure of a nuclear turbine building according to an embodiment of the present invention, and FIG. 9 is a sectional view taken along the E-E plane shown in FIG. 8. . ■... Turbine generator mount, 2... Building floor, 3...
- High pressure turbine, 4... Low pressure turbine, 5... Combination intermediate valve, 6... Generator, 8... Cross-around pipe, 9... Moisture separator, 12... Shielding plate, 13
．． 14...a-shielding wall, 16...shielding ceiling, 17...
Ceiling shield, 18... Screen-like shield, 19.21
... Shielding plate, 2o... Steam introduction pipe. Agent Patent Attorney Masami Akimoto 12 figures ￥3 figures

Claims (1)

[Claims] 1. In a nuclear power turbine that uses radioactive steam generated in a nuclear reactor directly as a driving source, the combination intermediate valve is separated from the turbine generator mount and supported by the building floor, and the above-mentioned A shielding structure for a nuclear power turbine building, characterized in that a combination intermediate valve and a moisture separator are installed in a shielding chamber isolated from a turbine generator. 2. Claim 1, characterized in that the above-mentioned combined intermediate valve is provided with a shield that extends over the steam introduction pipe connecting the combined intermediate valve and the low-pressure turbine.
Shielding structure of nuclear turbine building as described in Section 1.