JPH0433400B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) This invention relates to a nuclear reactor building structure for housing a nuclear reactor.

(Prior art) Conventionally, in a nuclear reactor building, the reactor core is supported by a strong pedestal, and a containment vessel and a shield wall are placed outside the pedestal through an internal space. Safety in the center of the building is ensured.

The containment vessel is a steel vessel-like structure with a plate thickness of approximately 40 mm, and is fixed to the pine slab via anchor bolts. In addition, the shield wall and pedestal are reinforced concrete structures, and many reinforcing bars are densely arranged.

Furthermore, in the case of nuclear reactor buildings, the inside of the building, which is a radiation controlled area, is isolated from the outside through a reinforced concrete outer wall, and the airtightness and watertightness of the outer wall is used to create a negative pressure inside, increasing the isolation effect. ing.

(Problems to be solved by this invention) As described above, the pedestal and the containment vessel are strong structures, and when the reactor fulfills its designated role and is dismantled, the following points should be taken into consideration to ensure that the demolition work is carried out safely. This poses a problem in terms of economic implementation.

(1) The containment vessel is radioactive throughout its entire thickness, and the shield wall and upper pedestal are radioactive to a considerable depth below the surface.

(2) It is difficult to dismantle because it is strong, and because the containment vessel and shield wall are close to each other but are made of different structural materials, the dismantling methods must be different, requiring a long construction period.

Therefore, it is desired that the structure be strong and fully functional during normal operation, and that it can be removed efficiently using the same construction method when dismantled.

The following points are also problematic regarding the exterior walls:

(1) Due to technological advances in the reactor core system, the barrier function required of the outer wall will now last for more than 40 years, and long-term planned maintenance is required to maintain this function.

(2) Furthermore, when a nuclear reactor has completed its role and is to be dismantled, the outer wall becomes an important point in carrying out the demolition work safely and economically.

Therefore, it is desirable to have an exterior wall that has good watertightness and airtightness during normal operation, maintains excellent insulation properties, requires no maintenance, and can be efficiently removed during demolition.

(Means for Solving the Problems) The present invention was developed in view of the above-mentioned problems, and this reactor building structure includes a pedestal that supports the reactor core, and an internal space connected to the outside of the pedestal. In the reactor building structure, which consists of a containment vessel, a shield wall, and an outer wall, all of which are made of concrete, unbonded high-tensile steel wires are arranged in a net shape in the concrete of the pedestal, containment vessel, and outer wall, and the ends are tightened. Reinforcing unbonded steel wires are anchored at or near the surface of the concrete and are placed under tension within the pedestal and containment concrete to interlock with the high tensile strength steel wires.

Example 1 A description will be given below based on the illustrated example. 1st
In the figure, a containment vessel 3 and a shield wall 4 are provided on the outside of a pedestal 1 that supports the reactor core via an internal space 2, and an outer wall 5 is provided on the outside, and each of these parts is made of concrete. ing.

Unbonded high-tensile steel wires 6 are buried under tension in the concrete walls of the pedestal 1, the containment vessel 3, and the outer wall 5, where activation is predicted, so as not to cause any adhesion. As shown in Fig. 2, the high-tensile steel wires 6 are arranged in a net shape in the vertical direction or diagonally, and the high-tensile steel wires 6 are divided into required lengths in consideration of the division division at the time of disassembly. and its ends are anchored at or near the concrete surface.

FIG. 7 shows an example of this anchoring part 12, in which a recess is provided on the surface of the concrete, a high-tensile steel wire 6 is made to protrude into this recess, and the end of the high-tensile steel wire 6 is tightened with an anchoring hardware 13. The recessed portion is filled with filling mortar 14. In this case, the positions of pillars and beams are utilized in areas of the outer wall 5 where the wall thickness is small, and the ends of the high-tensile steel wires 6 are fixed from those areas.

In the concrete of the pedestal 1 and the containment vessel 3, reinforcing unbonded steel wires 7 interlocking with the high-tensile steel wires 6 are buried under tension. This reinforcing unbonded steel wire 7 is bent in a wave-like manner and is arranged horizontally or vertically as required (FIG. 3).

The lower part of the building is made of reinforced concrete and is anchored by high-tensile steel wires 9 from the pine slab 8 in the lower layer. Note that no waterproof layer is provided on the five portions of the outer wall that are buried underground.

Embodiment 2 FIG. 4 shows a second embodiment. In this embodiment, in addition to high-tensile steel wires 6 and reinforcing unbonded steel wires 7, large-diameter reinforcing bars 10 are arranged in the concrete walls of the pedestal 1 and the containment vessel 3 to form a center core. As shown in FIG. 5, this large-diameter reinforcing bar 10 is
Placed upward, downward, or diagonally,
The large-diameter reinforcing bars 10 are connected by tie bars 11 as shown in FIG. 6, and braces may be provided depending on the situation.

As described above, in both the first and second embodiments, after the concrete reaches the required strength during construction, the unbonded high-tensile steel wire 6 is tensioned and then fixed.
Or, during demolition, according to the demolition classification, if necessary, release the tightening force or tension of the high-tensile steel wires 6 of the concrete part to be demolished, and further utilize the unbonded state to remove these high-tensile steel wires 6. It can be pulled out and the concrete can then be easily demolished.

(Effects of the Invention) As described above, according to the present invention, since the unbonded high-tensile steel wire is tightened under tension, cracks can be prevented and the structure can be provided with sufficient strength and rigidity, so that it can be stored as before. The container and shield wall can be designed as an integrated concrete structure rather than separate, and an expensive steel containment vessel can be omitted.

In addition, cracking and water intrusion of the exterior wall concrete are prevented, and there is no peeling of the concrete due to rusting of the reinforcing bars, so a large amount of maintenance can be omitted, and a waterproof layer can also be omitted for underground exterior walls.

Furthermore, since the high-tensile steel wire is not attached to the concrete, it can be easily pulled out. The removed parts will be made of unreinforced concrete, making it extremely easy to dismantle, and the other parts will have sufficient strength and rigidity to ensure the structural safety of the building during demolition.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view, Fig. 2 is a front view showing the arrangement of high-tensile steel wires, Fig. 3 is a front view showing the arrangement of reinforcing unbonded steel wires, and Fig. 4 is a front view of the second embodiment. 5 is a front view showing the arrangement of the large-diameter reinforcing bars, FIG. 6 is a longitudinal sectional view showing the arrangement of the large-diameter reinforcing bars, and FIG. 7 is the anchoring part of the high-tensile steel wire. FIG. 1... Pedestal, 2... Internal space, 3... Containment vessel, 4... Shield wall, 5... Outer wall, 6... High tensile strength steel wire, 7... Unbonded steel wire for reinforcement, 8... Pine slab, 9... High tensile strength steel wire, 10 ...Thick diameter reinforcing bar, 11
... Stirrup, 12... High-tensile steel wire fixing section, 13... Fixing hardware, 14... Filling mortar.

Claims (1)

[Claims] 1. In a reactor building structure where a pedestal supporting the reactor core and a containment vessel, a shield wall, and an outer wall are provided outside the pedestal through an internal space, and all of the reactor building structures are made of concrete, A network of unbonded high-tensile steel wires is placed and tensioned, the ends of which are anchored at or near the surface of the concrete, and reinforcing wires interlocked with the high-tensile steel wires are placed within the concrete of the pedestal and containment vessel. A nuclear reactor building structure characterized by unbonded steel wires arranged under tension.