JPH0498197A - Nuclear reactor building for nuclear power plant - Google Patents

Abstract

PURPOSE:To improve the soundness and reliability of equipment, pipings, etc., installed inside a building by providing shock absorbing materials capable of receiving flying matters at outer walls covering a nuclear reactor containment. CONSTITUTION:A number of shock absorbing materials 13 capable of receiving flying matters are installed to protrude at outer parts of roof parts 19, 21 and building outer wall parts 20, 22 of a nuclear reactor building 11 above the ground. The shock absorbing material 18 consists of a pair of steel plates 18a, 18b disposed facing each other, and a honeycomb 18c inserted between them, and the steel plate 18b on the side to be applied to the outer wall 20 is tightened and fixed at predetermined positions by a plurality of stud bolts 23 and nuts 24. When broken pieces or the like come flying toward the nuclear reactor building 11, the flying matters first collide with the steel plate 18a on the surface side of the shock absorbing material 18 to be received. An intact by the flying matters is thus received to damp by the shock absorbing material 18, and an impact transmitted to the reactor outer wall can be at a very low level, so direct effects to the reactor building 11, that is occurrence of accidents by damage or vibration of the outer walls can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a reactor building of a nuclear power plant in which a reactor containment vessel is installed.

(Prior Art) An example of a reactor building of a nuclear power plant is shown in FIG. This reactor building 1 is a reactor building of a boiling water nuclear power plant, and inside this reactor building 1, a reactor containment vessel 3 containing a reactor pressure vessel 2 is housed. The reactor containment vessel 3 serves as a pressure barrier in the event of a hypothetical accident such as a rupture of a main steam pipe.

The reactor building 1 is built directly on solid bedrock 4, and the building blocks that make up the structurally important floors and walls, such as the foundation mat 5, outer box wall 6, and inner box wall 7, of the reactor building 1 are built directly on solid rock 4. The thickness is determined based on the expected excitation force to the reactor building 1 based on the scale of an earthquake expected in the area where the power plant is installed, the distance from the epicenter, etc.

When locating the reactor building 1 in such a nuclear power plant, a location that can sufficiently maintain the safety of the nuclear power plant is considered and selected. The presence or absence of facilities to protect against the possibility of accidents will be considered.

Specifically, Japan's nuclear power plants are located in locations where there are no airfields in the vicinity, and if there is an air route over the nuclear power plant, it is difficult for aircraft to fly over the plant. Aircraft are considered to be in cruising mode even if they are regulated or are flying in an airway over a nuclear power plant.

Since the probability of an aircraft falling into a nuclear power plant is set to almost zero, there is generally no need to consider the impact of falling aircraft on nuclear power plants, and nuclear power plants, which are important for safety, do not need to consider the effects of falling aircraft. The design mainly focuses on the earthquake force mentioned above.

(Problem to be solved by the invention) However, as the demand for electricity has expanded in recent years, many nuclear power plants have been installed, and the number of locations with suitable location conditions for the installation of nuclear power plants has decreased relatively. It's coming. For this reason, it is becoming increasingly difficult to select locations for installing nuclear power plants. Under these circumstances, is the location of a new nuclear power plant considered to be offshore or on flexible ground, and if so, is it necessary to deal with accidents at transportation facilities or where there is a possibility of accidents such as explosions? It is necessary to take safety measures for the facility.

In addition, the future development of the aircraft business is expected to result in the construction of new airports and an increase in the number of air routes, and depending on the location where new nuclear power plants are installed, they may be difficult to protect against the possibility of an aircraft falling. It is becoming more likely that design considerations will have to be taken into account.

The present invention was made in consideration of the above-mentioned circumstances, and assumes a collision between various flying objects such as debris from an aircraft accident or an explosion at a facility and a nuclear reactor building, and damages the reactor building in the event of a collision. and can reduce vibration,
The purpose of the present invention is to provide a reactor building for a nuclear power plant that can improve the soundness and reliability of equipment, piping, etc. installed in the reactor building.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a reactor building of a nuclear power plant comprising an outer wall of a predetermined structure covering a reactor containment vessel, in which the outer wall is provided with a structure that protects the outer wall from flying objects. It is equipped with a shock absorbing device that can absorb the impact.

(Function) In a means having such a configuration, in the event that an aircraft crashes or explodes and debris flies toward the reactor building, those flying debris are attenuated by the shock absorber. The system is now shut down, reducing the direct impact force on the reactor building.

(Example) Hereinafter, an example of a nuclear reactor building of a nuclear power plant according to the present invention will be described with reference to the accompanying drawings.

The reactor building 11 of the embodiment shown in FIG. 1 is a reactor building of a boiling water nuclear power plant, and a reactor pressure vessel is installed approximately in the center inside the reactor building 11. The reactor containment vessel containing the reactor is also housed (see numbers 2 and 3 in Figure 6).

The reactor containment vessel acts as a pressure barrier in the event of a hypothetical accident such as a main steam pipe rupture.

The reactor building 11 is constructed directly on a solid bedrock 14, and the reactor building 11 has a foundation mat 15, an outer box wall 16, an inner box wall soil 7, and other structurally important floors and walls. The thickness of the reactor building 11 is determined based on the expected excitation force to the reactor building 11 based on the scale of an earthquake expected in the area where the nuclear power plant is installed, the distance from the epicenter, etc. Specifically, the thickness of the base mat 1-5 is set to, for example, about several meters, and the thickness of the bases of the outer box wall 16 and the inner box wall 17 is set to, for example, about 2 meters.

In addition, each roof section 19 in the above-ground part of the reactor building 1,000
．． A large number of shock absorbing devices 18 capable of receiving flying objects are installed on the outside of the building wall 21 and the building outer wall 20, 22, respectively, in a protruding manner.

As shown in FIG. 2(A), each of these shock absorbers 18 includes a pair of steel plates 18a facing each other,
A honeycomb 18C is inserted between the outer wall 2 and the outer wall 18b, as shown in FIG. 2(B).
The steel plate on the side that comes into contact with the 0 side], 8b is tightened and fixed in a predetermined position by a plurality of stud bolts 23 and nuts 24.

In such an embodiment, if there is an aircraft fall or an explosion accident and debris or the like flies toward the reactor building 11, those flying objects first collide with the steel plate 18a on the front side of the shock absorber 18. The reception will be stopped. The honeycomb 18c is deformed by this impact force on the steel plate 18a, and the impact force is absorbed.

Does the deformation at this time occur in a direction perpendicular to the collision direction?If multiple shock absorbers 18 are arranged in parallel as in this embodiment, the amount of deformation due to shock absorption will be large. At the same time, the shock absorber T8 after the collision
It is possible to improve the efficiency of work such as replacement or maintenance/inspection during normal operation.

In this way, the impact force from flying objects is attenuated by the impact buffer 18, and the impact force transmitted to the reactor outer wall is kept at an extremely low level. For example, damage to external walls and accidents caused by vibrations can be avoided.

Next, a modification of the shock absorbing device will be described with reference to FIG. 3. Components corresponding to those of the embodiment shown in FIG. 2 will be described with the same reference numerals. In the case shown in FIG. 3, the steel plates 18a and 18b of the shock absorber 28 are
A plurality of coil springs 18d are attached between the two. Similarly, in the embodiment shown in FIG. 4, a foamed body 18e made of urethane or the like is inserted between the shock absorbing device 38 and the steel plates 18a and ↑8b.

In this embodiment as well, it is possible to obtain the same functions and effects as in the first embodiment.

Furthermore, in the embodiment shown in FIG.
．． A plurality of shock absorbers 18 against flying objects are installed on the outside of the reactor building 1.
Notch-shaped inclined surfaces 30 and 31 are formed at each ridge edge of each roof section 19.21 and building outer wall section 20.

In such an embodiment, the reactor building 11 is formed into a polygonal shape, thus reducing the probability of a flying object colliding with the reactor building ↑1. Furthermore, similar actions and effects can be obtained by forming each edge of the reactor building 11 into a curved shape.

〔Effect of the invention〕

As described above, in the reactor building of a nuclear power plant according to the present invention, it is assumed that there is a collision between the reactor building and various flying objects such as debris from an aircraft accident or a facility explosion.
Even if these flying objects collide with the reactor building, the shock absorber will attenuate them and absorb the impact force, so the direct impact force on the reactor building will be weakened, and when a collision occurs, Damage and vibration to the reactor building can be reduced, and the health and reliability of equipment, piping, etc. installed in the reactor building can be improved.

[Brief explanation of drawings]

FIG. 1 is an external perspective view showing one embodiment of a reactor building of a nuclear power plant according to the present invention, and FIGS. 2(A) and (B)
Figure 1 is an external perspective view showing the structure of the shock absorber used in the reactor building, and a diagram showing its installation state. Figures 3 (A) and (B) are other views of the shock absorber used in the reactor building. FIGS. 4(A) and 4(B) are external perspective views showing still another embodiment of the shock absorbing device and views showing its installed state. 5 is an external perspective view showing another embodiment of the reactor building of a nuclear power plant according to the present invention, and FIG. 6 is a vertical cross-sectional view showing an outline of the arrangement inside the reactor building. 11... Reactor building, 18.28.38... Shock absorber, 18a, 18b... Steel plate, 18c... Honeycomb, 18d... Coil spring, ↑8e ・Foam, 19, 20, 21.22... Building exterior wall. (A) k゛(B) (A) Fig. zu (A) (B) Part ■

Claims (1)

[Claims] A nuclear power plant reactor building comprising an outer wall having a predetermined structure covering a reactor containment vessel, wherein the outer wall is provided with a shock absorbing device capable of receiving flying objects. nuclear reactor building.