JPS5860290A - Shielding structure of atomic power turbine - 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 nuclear power turbine, and more particularly to a shielding structure for a nuclear power turbine that prevents the spread of radioactivity.

Compared to thermal power plants, nuclear power plants use low-temperature, low-pressure steam with a large specific volume, so the equipment itself has a large capacity, and there are many protective walls inside the building to prevent the spread of radioactivity. The entire building became large,
Huge construction costs are required. In order to deal with this problem, in recent years, various studies have been conducted to make buildings more compact by rationally arranging equipment installed inside the buildings. Turbine buildings are no exception; new layouts have been adopted in recent years.

In a boiling water atomic coupler plant, a shielding wall is required to prevent steam generation, so auxiliary equipment is placed below the building floor, and the ceiling, floor, and walls are made of thick concrete to prevent radiation sources. There is.

In addition, since the height of the building above the floor is high, it is difficult to thicken the walls and roof due to the building structure.
It is common for radiation source countermeasures to be taken at the equipment, not at the building.

A conventional structure will be explained with reference to FIGS. 1 to 3.

The floor surface is a turbine built as a foundation with sufficient strength to install the extremely heavy turbine and generator.
It consists of a generator mount 1 (hereinafter referred to as T-G mount) and a building floor 2. A high-pressure turbine 3, a low-pressure turbine 4, a generator 6, and an exciter 7 are arranged on the T-G mount 1, and the intermediate valve 5 is connected to the T-G by a support attached to the T-G mount 1.
It is placed beside the G frame 1.

Exhaust steam from the high-pressure turbine 3 passes through a cross-around pipe 8 located below the floor and flows into the low-pressure turbine 4 via an intermediate valve 5.

Openings 10 are provided in the floor surface for the cross-around pipe 8 and the intermediate valve 5.

A moisture separator 9 is provided in the middle of the cross-around tube 8 to separate moisture from the steam.

Furthermore, the reactor feed water pump and drive turbine 1 are installed on the floor.
Two units of 1 are installed each.

It is important to prevent the diffusion of radioactivity from an atomic couplant so that it does not affect the surrounding environment, but above the floor, it is possible to obtain a shielding effect with the walls of the building as described above. It is structurally difficult. For this reason, among the equipment installed on the floor, the high-pressure turbine 3, which has a relatively high radiation source concentration, the intermediate valve 5, and the steam introduction pipe 20 from the intermediate valve 5 to the low-pressure turbine 4 are equipped with steel plate shielding plates. 12.19 to cover the entire surface to prevent the spread.

Further, the reactor feed water pump and drive turbine 11 are surrounded by a concrete shielding wall 13 to obtain the same effect.

Recently, in order to make the turbine building itself more compact, it has been proposed to replace the conventional arrangement of turbine auxiliary machinery as shown in FIGS. 1 to 3.

The proposal is shown in Figures 4 and 5.

The turbine-generator placed on the T-G pedestal 1 is the same as the conventional arrangement, but the reactor feed water pump and drive turbine, which were placed conventionally, are placed below the operating floor, and are instead placed on the building floor 2. Above, moisture separators 9 are installed on the left and right sides of the low pressure turbine 4.

Along with this, the cross-around tube 8, which has a relatively high concentration,
The piping was also installed above the operating floor surface, and a shielding wall 14 covering all of these was installed on the building floor 2 as a moisture separator room. This moisture separator room is provided with a ceiling 16 that also serves as a support 15 for suspending the moisture separator 9 and for preventing diffusion into the sky.

However, the shielding wall 14 is formed integrally with the building floor 2, and the T-
Considering that the construction method is different from the G mount 1 and the equipment installation, maintenance and inspection, etc., completely covering the intermediate valve 5 with the shielding wall 14 will impair work efficiency. Requires cover.

The present invention has been made in view of the above circumstances, and its purpose is to obtain a shielding structure for a nuclear power turbine that is simple in structure and easy to maintain.

That is, a feature of the present invention is that, in a nuclear power turbine in which radioactive steam generated from a nuclear reactor is directly used as its driving steam and this driving steam drives high-pressure and low-pressure turbines, the high-pressure turbine is shielded using a shielding plate, and An intermediate valve and a moisture separator that separates moisture from the steam are installed on both sides of the low-pressure turbine, and these intermediate valves and moisture separators are covered with a shielding wall. A shielding structure for a nuclear power turbine is characterized in that a shield plate is passed between the ceilings and a vertical shield plate is provided in the axial direction of the low-pressure turbine, and the low-pressure turbine is covered with both of these shield plates and the shield wall. be.

An embodiment of the present invention will be described below with reference to FIGS. 6 and 7. In the drawings, explanations of parts that are the same as those in FIGS. 1 to 5 will be omitted, and only the parts that characterize the present invention will be explained. On the building floor 2, an intermediate valve 5 and a moisture separator 9 are installed on both left and right sides of the low pressure turbine 4. The intermediate valve 5 and the moisture separator 9 are covered with a shielding wall 14, and the moisture separator 9 is suspended from the ceiling 16 via a support 15. A shield plate F is passed between the ceilings 16 to cover the upper surface of the low pressure turbine 4. This ceiling shield plate 17 is a relatively thin steel plate (for example, about 16 mm thick) that satisfies the purpose of shielding, and also serves as a barrier in the unlikely event that a turbine missile occurs. It is also effective as A vertical shield plate 1 is provided between the low pressure turbine 4 and the high pressure turbine 30 and between the low pressure turbine 4 and the generator 60, that is, in the axial direction of the low pressure turbine 4.
8 is provided up to the height of the ceiling shield plate 17.

Furthermore, since there are no obstacles around the high-pressure turbine 3, diffusion is prevented by a box-shaped shielding plate 12 similar to the conventional structure.

The low-pressure turbine 4, the intermediate valve 5, and the moisture separator 9 can be shielded by the shielding wall 14 and the shield plates 17, 18.

Although not directly related to the present invention, since both the moisture separator room and the low-pressure turbine section have a sealed structure, ventilation air conditioning should be installed in these rooms to prevent the ambient temperature from rising due to radiated heat. That's fine.

According to the present invention, the shield plate that performs shielding has a simple structure, is easy to maintain, and provides an excellent shielding effect together with the shielding wall.

[Brief explanation of drawings]

Figure 1 is a plan view of the conventional turbine floor, Figure 2 is a sectional view taken along line A-A in Figure 1, and Figure 3 is taken along line B-B in Figure 1.
4 is a plan layout of a turbine operating floor recently proposed to make the turbine building itself compact; FIG. 5 is a sectional view taken along line C-C in FIG. 4; and FIG. FIG. 7 is a plan layout diagram showing one embodiment of the turbine shielding structure, and FIG. 7 is a sectional view taken along line DD in FIG. 6.

Claims (1)

[Claims] 1. In a nuclear power turbine in which radioactive steam generated from a nuclear reactor is directly used as its driving steam and this driving steam drives high-pressure and low-pressure turbines, the high-pressure turbine is shielded using a shielding plate, and both sides of the low-pressure turbine are An intermediate valve and a moisture separator to separate moisture from the steam are installed on the surface.
These intermediate valves and moisture separators are covered with a shielding wall,
A shield plate is passed between the ceilings of both shield walls, and a vertical shield plate is installed in the axial direction of the low pressure turbine.
A shielding structure for a nuclear power turbine is characterized in that a low pressure turbine is covered with these shield plates and a shielding wall.