JP7395757B2 - Turbine equipment and turbine equipment inspection methods - Google Patents

Description

The present invention relates to turbine equipment used in a boiling water nuclear power plant (hereinafter referred to as BWR) and a method for inspecting the turbine equipment.

Patent Document 1 discloses a method for disassembling and reassembling only the central shielding plate and the middle shielding plate, leaving the outer shielding plate in the installed state, and eliminating disassembly and reassembly to shorten the periodic inspection period. In the low-voltage shielding plate, the joint structure between the middle shielding plate and the outer shielding plate is changed, and the disassembly is performed in the order of the central shielding plate and the middle shielding plate, while the outer shielding plate remains installed. It is stated that.

Patent Document 2 discloses that, for the purpose of improving the workability and reliability of joining a pair of split casings, a through hole is bored in the split casing, and a through hole is formed on the joint surface side of the split casing of the through hole. A large-diameter counterbore is formed, and a bulge portion is provided on both bolts that are inserted into the through-hole, and the diameter is larger than the through-hole and smaller than the counterbore. Nuts with almost the same strength can be fixed, and the bulging parts of both tightening bolts are locked to the counterbore of one of the split casings, and the bolts are inserted from the outside of one of the split casings to one end of both tightening bolts. After screwing the nut and fixing it non-rotatably to this bolt, insert the other end of this double-tightened gel into the other through hole of the split casing, and insert a nut different from the nut from the outside of the other split casing. It is stated that they screw together.

Japanese Patent Application Publication No. 01-216003 Japanese Unexamined Patent Publication No. 59-203811

In a boiling water nuclear power plant (BWR), primary steam heated in a nuclear reactor directly rotates a turbine to drive a generator and generate electricity.

Due to this structure, the turbine equipment needs to have a shielding function in order to reduce the influence of direct radiation on peripheral equipment and the outside of the building. Regarding the shielding function of turbine equipment, in addition to a structure in which the steel casing of the turbine itself has a sufficient plate thickness, a structure in which a concrete shield is installed around the turbine has been put into practical use.For example, Patent Documents 1 and 2 There is a technique described in .

Turbine equipment at nuclear power plants receives high-pressure steam and rotates at high speed to drive the generator. Therefore, in order to maintain the specified performance of the turbine equipment, the turbines must be inspected during periodic inspections at nuclear power plants. It is necessary to open the concrete shield and inspect and repair the rotor, rotor, etc.

At this time, space will be required within the building to temporarily place a concrete shield around the turbine. However, if a space is provided for this temporary storage, the turbine building needs to be built wider to accommodate the temporary storage space, which increases the time and cost required for construction. was there.

The present invention provides turbine equipment and a method for inspecting turbine equipment that allow the building to be made smaller than conventional ones.

The present invention includes a plurality of means for solving the above problems, and one example thereof is a turbine equipment for a boiling water nuclear reactor, which includes a turbine and a plurality of shielding bodies covering the turbine. Each of the plurality of shielding bodies has a laminated structure with respect to the other shielding bodies.

According to the present invention, it is possible to downsize the building compared to the conventional structure. Problems, configurations, and effects other than those described above will be made clear by the description of the following examples.

It is a figure showing an outline of turbine equipment of a reference example. FIG. 2 is a diagram showing an outline of the turbine equipment of the reference example before inspection. It is a figure showing the outline at the time of inspection of turbine equipment of a reference example. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the outline of the turbine equipment of this invention. FIG. 2 is a diagram showing an overview of the turbine equipment of the present invention before inspection. FIG. 2 is a diagram showing an overview of the turbine equipment of the present invention during inspection. It is a figure showing an outline of a concrete shield among turbine facilities of the present invention. FIG. 3 is a diagram showing details of a concrete shield in the turbine equipment of the present invention. It is a figure showing the state where concrete shielding bodies of turbine equipment of the present invention were laminated. It is a figure showing the outline of other forms of concrete shielding among turbine facilities of the present invention. FIG. 3 is a diagram showing details of a concrete shield in the turbine equipment of the present invention. It is a figure showing the state where concrete shielding bodies of turbine equipment of the present invention were laminated.

Embodiments of the turbine equipment and turbine equipment inspection method of the present invention will be described with reference to FIGS. 1 to 12.

First, differences in outline between a reference example of turbine equipment in a BWR and the present invention will be explained using FIGS. 1 to 6. FIG. 1 is a diagram showing an outline of the turbine equipment of the reference example, FIG. 2 is a diagram showing the outline of the turbine equipment of the reference example before inspection, and FIG. 3 is a diagram showing an outline of the turbine equipment of the reference example at the time of inspection. FIG. 4 is a diagram showing an outline of the turbine equipment of the present invention, FIG. 5 is a diagram showing an outline of the turbine equipment of the invention before inspection, and FIG. 6 is a diagram showing an outline of the turbine equipment of the invention at the time of inspection.

The turbine equipment of the present invention is suitably applied to a newly installed BWR, an ABWR (Advanced Boiling Water Reactor), or a derivative type of BWR.

In a typical BWR turbine equipment 110 as shown in FIGS. 1 and 2, the floor 122 includes, from the upstream side where steam flows, a high-pressure turbine 40, a plurality of (three in FIG. 1) low-pressure turbines 30, They are arranged in the order of generators 50.

During regular inspections of the high-pressure turbine 40, low-pressure turbine 30, and generator 50, as shown in FIGS. 34, the upper casing in the upper casing mounting space 35, the lower casing in the lower casing mounting space 36, and the concrete shielding body 111 in the concrete shielding space 37.

Note that FIG. 1 describes the case of a low-pressure turbine 30. Moreover, FIG. 1, FIG. 2, and FIG. 3 show the case where the position of the concrete shield mounting space 37 is different.

In such a typical BWR turbine facility 110, the casings of the high-pressure turbine 40 and low-pressure turbine 30 themselves have shielding performance as radiation shielding structures, or the casings of the high-pressure turbine 40 and low-pressure turbine 30 are surrounded by concrete. Structures such as surrounding it with a shielding body are used.

In the boiling water reactor turbine equipment 100 of the present invention shown in FIGS. 4 and 5, a high-pressure turbine 40 and a plurality of (three in FIG. 1) low-pressure turbines 30 are arranged on the floor 22 from the upstream side where steam flows. , generator 50 are arranged in the same order. Further, the low pressure turbine 30 is covered with a concrete shield 1A on the floor 22.

In the turbine equipment 100 of the present invention, for the low pressure turbine 30, the concrete shield 1A of the low pressure turbine 30 having a radiation shielding function is used as a shield. This concrete shielding body 1A has a structure that covers the low pressure turbine 30 in a plurality of pieces in the axial direction of the low pressure turbine 30.

Further, each of the concrete shielding bodies 1A in the turbine equipment 100 of this embodiment has a laminated structure with respect to the other concrete shielding bodies 1A.

During the operation of the nuclear power plant, the concrete shield 1A is installed on a predetermined low pressure turbine 30. On the other hand, during regular inspections of nuclear power plants (for example, once every 18 months in North America), the multiple low-pressure turbines 30 are sequentially disassembled and inspected. need to be temporarily removed.

Therefore, the concrete shielding body 1A of the target low-pressure turbine 30 is not placed in the temporary storage space 4, but as shown in FIG. Layer on top of 1A. After the inspection of the target low-pressure turbine 30 is completed, the concrete shield 1A is returned onto the original low-pressure turbine 30.

By sequentially performing this work at the time of inspection, the concrete shield mounting space 37 becomes unnecessary and it becomes possible to reduce the laydown space of the turbine building. That is, in the turbine equipment 100 of this embodiment, the parts to be placed in the temporary storage space 4 during periodic inspection are mainly the rotor, upper casing, lower casing, and diaphragm of the target low-pressure turbine 30. becomes.

Next, details of the structure of the concrete shielding body 1A will be explained using FIGS. 7 to 9. FIG. 7 is a diagram showing an outline of a shielding structure of the turbine equipment of the present invention, FIG. 8 is a diagram showing details of a concrete shielding body having a laminated structure, and FIG. 9 is a diagram showing a laminated state. .

As shown in FIG. 7, a plurality of concrete shielding bodies 1A cover the low-pressure turbine 30 from above the casing in the axial direction of the low-pressure turbine 30. As shown in FIGS. 7 and 8, a key structure 10 is provided at the contact portion with the shield 1A as a measure against radiation leakage. This key structure 10 does not prevent the leakage of radioactive substances, but rather the leakage of radiation that follows a substantially linear trajectory. good.

Moreover, as shown in FIG. 8, each of the concrete shielding bodies 1A has a thickness in the radial direction of the low-pressure turbine 30, in which the thickness of the base portion 7A is smaller than that of the arch portion 6 covering the upper part of the low-pressure turbine 30. It has a thick structure.

Furthermore, a key structure convex portion 8A is provided on the upper side of the foundation portion 7A of the concrete shielding body 1A, and a key structure recess portion 8B is provided on the lower side of the foundation portion 7B, so that external events such as earthquakes can occur during stacking during periodic inspections. It has a structure that prevents lateral displacement in the event of occurrence. The key structure convex portion 8A and key structure concave portion 8B for preventing lateral displacement can also be used for positioning when attaching the concrete shield 1A.

When such concrete shielding bodies 1A are stacked, as shown in FIG. 9, the concrete shielding body 1A removed from the low-pressure turbine 30 to be inspected is placed on top of the concrete shielding body 1A of the low-pressure turbine 30 not to be inspected. Laminate. At this time, the keys are stacked so that the key structure concave portion 8B of the concrete shield 1A of the removed low-pressure turbine 30 fits into the key structure convex portion 8A of the base portion 7A of the concrete shield 1A of the low-pressure turbine 30 that is not subject to inspection.

Note that there is only one high-pressure turbine 40 in the turbine equipment 100, and there is no particular stacking destination. Furthermore, since it is structurally difficult to laminate them, there is no need to forcibly adopt a laminate structure.

Next, variations in the form of the concrete shield will be explained using FIGS. 10 to 12. FIG. 10 is a diagram showing an outline of another form of concrete shielding body in turbine equipment, FIG. 11 is a diagram showing details of a concrete shielding body having a laminated structure, and FIG. 12 is a diagram showing a laminated state. be.

The concrete shield 1B shown in FIG. 10 has a radiation shielding function like the concrete shield 1A shown in FIG. 7 etc., and covers the low pressure turbine 30 in the axial direction of the low pressure turbine 30. It is. Further, a key structure 10 is provided as a measure against radiation leakage.

The concrete shielding body 1B shown in FIGS. 10 and 11 has bolt holes 9A in the base portion 7B instead of the key structure convex portion 8A and the key structure concave portion 8B of the concrete shielding body 1A.

As shown in FIG. 12, this bolt hole 9A is formed when the concrete shielding body 1B removed from the low-pressure turbine 30 to be inspected is stacked on the concrete shielding body 1B of the low-pressure turbine 30 not to be inspected. The bolts 9B are provided to prevent the laminated concrete shielding body 1B from shifting laterally.

Next, the effects of this embodiment will be explained.

The turbine equipment 100 of the present embodiment described above is for a boiling water nuclear reactor, and includes a low-pressure turbine 30 and a plurality of concrete shielding bodies that cover the low-pressure turbine 30, and each of the plurality of concrete shielding bodies is different from the other. It has a laminated structure with a concrete shielding body. Preferably, the concrete shield is a concrete shield 1A, 1B covering the casing of the low pressure turbine 30.

As a result, the concrete shield mounting space 37 can be reduced compared to the temporary storage space 3 when a conventional shield is used, so the space required for the temporary storage space 4 can be reduced. Therefore, the laydown area of the building that houses the turbine equipment 100 is reduced, and the construction area of the building itself can be reduced compared to conventional buildings. Therefore, it is possible to contribute to reducing the construction cost of a nuclear power plant.

In addition, the shielding body has a key structure convex part 8A and a key structure concave part 8B, or the concrete shielding body has bolt holes 9A, so that when an earthquake occurs during stacking, concrete It is possible to suppress the occurrence of unexpected situations such as the shielding body slipping down.

Furthermore, the shielding body covers the low pressure turbine 30 with a plurality of concrete shielding bodies 1A, 1B in the axial direction of the low pressure turbine 30, and the key structure 10 is provided in each of the concrete shielding bodies 1A, 1B. Therefore, measures against radiation leakage other than the concrete shields 1A and 1B are not required, and the structure of the turbine equipment 100 can be further simplified.

Furthermore, the thickness of the shield in the radial direction of the low-pressure turbine 30 is such that the thickness of the base parts 7A and 7B is thicker than that of the arch part 6 that covers the upper part of the low-pressure turbine 30, thereby stabilizing the concrete shield during stacking. be able to.

<Others>
Note that the present invention is not limited to the above-described embodiments, and various modifications and applications are possible. The embodiments described above are described in detail to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to having all the configurations described.

1A, 1B... Concrete shielding body with shielding performance 3... Temporary storage space 4... Temporary storage space 6... Arch portion 7A, 7B... Foundation portion 8A... Key structure convex part (key structure for preventing lateral slippage)
8B...Key structure recess (key structure for preventing lateral slippage)
9A...Bolt hole (Bolt hole for preventing lateral slippage)
9B...Bolt 10...Key structure (radiation leakage prevention key structure)
22... Floor 30... Low pressure turbine 32... Rotor mounting space 34... Diaphragm mounting space 35... Upper casing mounting space 36... Lower casing mounting space 37... Concrete shield mounting space 40... High pressure turbine 50... Generator 100 …Turbine equipment 110…Turbine equipment 111…Concrete shielding body 122…Floor

Claims (6)

Turbine equipment for a boiling water reactor,
turbine and
a plurality of shielding bodies covering the turbine;
Each of the plurality of shielding bodies has a laminated structure with respect to the other shielding bodies ,
The thickness of the shield in the radial direction of the turbine is such that a base portion has a thickness greater than an arch portion covering an upper portion of the turbine.
Turbine equipment characterized by: The turbine installation according to claim 1,
The turbine equipment, wherein the shielding body is a concrete shielding body that covers a casing of the turbine. The turbine installation according to claim 1,
The turbine equipment, wherein the shielding body has a key structure for preventing lateral slippage. The turbine installation according to claim 1,
The turbine equipment, wherein the shielding body has bolt holes for preventing lateral slippage. The turbine installation according to claim 1,
The shielding body covers the turbine with a plurality of concrete shielding bodies in the axial direction of the turbine,
A turbine facility characterized in that each of the plurality of concrete shielding bodies is provided with a radiation leakage prevention key structure. A method for inspecting turbine equipment for a boiling water reactor comprising a turbine and a plurality of shielding bodies covering the turbine, the method comprising:
Using a plurality of shielding bodies each having a laminated structure with respect to the other shielding bodies,
A method for inspecting turbine equipment, characterized in that, when inspecting the turbine equipment, the shielding body of the turbine to be inspected is stacked on the shielding body of the turbine not to be inspected.

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