JPH09211169A - Reactor shielding wall structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shielding structure which can construct a reactor shielding wall easily and in short a time and has high shielding effect. SOLUTION: A reactor shielding wall 10 is constituted by arranging a cylindrical inner wall member 11 around a reactor pressure vessel 20, arranging a cylindrical outer wall member 12 outside the inner wall member 11 with a specific gap, and filling spherical lead compound balls 30 of specific size which are formed with surface layer of lead with a specific thickness and containing inside boron or boron compound, as shielding member 14 in the containing space 13 formed in between the inner wall member 11 and the outer wall member 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield wall structure which is disposed outside a reactor pressure vessel and shields radiation emitted from the reactor pressure vessel.

[0002]

2. Description of the Related Art As shown in the conceptual configuration of a nuclear reactor in a nuclear power generation facility, a reactor containment vessel 2 for accommodating major reactor equipment is provided in a reactor building 1, and the reactor containment vessel 2 is provided therein. The pressure vessel 3 is arranged and configured.

Around the reactor pressure vessel 3, when an operator works in the reactor containment vessel 2, the reactor pressure vessel 3
A cylindrical reactor shield wall 4 is provided to prevent exposure to radiation emitted from the reactor.

The reactor shielding wall 4 is constructed by forming a cylindrical frame body having a predetermined thickness as a whole from a steel plate, and filling the space in the thick portion of the frame body with concrete. That is, the concrete surface is covered with a steel plate. The frame body made of a steel plate is formed discontinuously by partitioning the internal space into a predetermined size in the circumferential direction and the vertical direction, and the construction is performed by sequentially pouring concrete from the lower space.

[0005]

However, in the conventional reactor shield wall structure as described above, concrete is poured into each of the discontinuous spaces which are partitioned into a predetermined size and are constructed. However, there is a problem that it is difficult to completely fill the space with concrete without a gap, a long construction period is required, and as a result, the cost also increases.

The present invention has been made in view of the above problem, and provides a reactor shield wall structure capable of constructing a reactor shield wall easily and in a short period of time and having a high shielding effect. The purpose is to

[0007]

A reactor shield wall structure according to the present invention that achieves the above object is a cylindrical reactor shield wall that covers the outside of a reactor pressure vessel. A cylindrical inner wall member is disposed around the inner wall member, and a cylindrical outer wall member is disposed outside the inner wall member at a predetermined distance, and is disposed in a housing space formed between the inner wall member and the outer wall member. The surface layer is constituted by containing boron or a boron compound therein with lead having a predetermined thickness, or being filled with a spherical shielding member formed of a radiation absorbing material such as iron or lead. To do.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a vertical cross-sectional view of the periphery of a reactor pressure vessel to which an example of a reactor shield wall structure according to the present invention is applied.

The reactor shield wall 10 includes an inner wall member 11 made of a steel plate having a predetermined thickness and an outer wall member 1 made of a steel plate having the same thickness.
2, the entire shape is formed into a cylindrical shape, and the reactor pressure vessel 20 is arranged so as to cover the outer periphery around the center thereof.

The inner wall member 11 has a cylindrical shape having an inner diameter capable of accommodating the reactor pressure vessel 20, the outer wall member 12 has a larger diameter than the inner wall member 11, and the inner peripheral surface 12A thereof has the inner wall member 11.
It has a cylindrical shape with a predetermined distance from the outer peripheral surface 11A. The outer peripheral surface 11A of the inner wall member 11 and the outer wall member 1
The interval between the two inner peripheral surfaces 12 is set based on the shielding ability of the shielding member 14 described later.

By the outer peripheral surface 11A of the inner wall member 11 and the inner peripheral surface 12A of the outer wall member 12, a cylindrical accommodation space 1 is formed.
3, the housing space 13 is filled with a shielding member 14 as shown in FIG. 2, which is an enlarged view of a portion A of FIG.

As the shielding member 14, for example, as shown in an enlarged sectional view of FIG. 3, a surface layer 31 is formed of lead having a predetermined thickness, and a boron or a boron compound 32 is contained therein (in other words, For example, a lead composite sphere 30 in which a lead surface layer 31 is formed on the surface of the core of boron or a boron compound 32) is used. The shape does not have to be so-called round (a set of points equidistant from the center) spherical, and may be indefinite. Also,
Its size is set sufficiently small with respect to the space 13.

A reactor shield wall 10 constructed as described above.
According to this, the surface layer 31 of the lead composite sphere 0 which is the shielding member 14
Lead absorbs γ-rays, and the internal boron or boron compound 32 absorbs neutrons, thereby efficiently absorbing and shielding γ-rays and neutrons having strong penetrating power emitted from the reactor pressure vessel 20. it can. Further, since the lead composite sphere 30 as the shielding member 14 in the above example contains the boron or the boron compound 32 having a small specific gravity inside the lead surface layer 31, a sphere formed entirely of lead is used. Compared with the case, the overall weight can be made lighter, and the inner wall member 11 and the outer wall member 12 do not require large strength.

The construction can be carried out by installing the inner wall member 11 and the outer wall member 12 and then filling the housing space 13 with the shielding member 14 (lead composite sphere 30) from the upper opening thereof. It is easier and the construction period can be shortened compared to the shielding wall.

As the inner wall member 11 and the outer wall member 12,
It is also possible to use the conventional frame body used for the reactor shield wall made of concrete as it is and fill the shield member 14 in this example in place of concrete. By doing so, the shielding member 14 according to this configuration has a higher shielding ability than concrete, so that a higher shielding effect can be obtained.

As another example of the shielding member 14, as shown in FIG. 4 which is a partially enlarged view, an iron ball 40 entirely made of iron and a lead ball 50 entirely made of lead at a predetermined ratio. You may mix and use it. Like this, iron ball 40
By mixing and using the lead ball 50 and the lead ball 50, it is possible to reduce the lead ball 50 having a larger specific gravity and contribute to the reduction of the overall weight.

[0017]

As described above, according to the reactor shield wall structure of the present invention, the space between the inner wall member disposed around the reactor pressure vessel and the outer wall member on the outer side thereof is provided. Since the spherical shielding member formed of the radiation absorbing material is filled and configured, the reactor shielding wall can be easily and quickly constructed, the construction cost can be reduced, and lead and A high shielding effect can be obtained by using iron.

Further, as the shielding member, a surface layer formed of lead having a predetermined thickness and containing boron or a boron compound therein is used, whereby the lead of the surface layer absorbs γ-rays and The above boron or boron compound absorbs neutrons, and can effectively shield and shield neutrons and neutrons with strong penetrating power emitted from the reactor pressure vessel.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of the periphery of a reactor pressure vessel to which an example of a reactor shield wall structure according to the present invention is applied.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is an enlarged cross-sectional view of a lead composite sphere that is a shielding member.

FIG. 4 is a partially enlarged view of a reactor shield wall showing a filling state of another example of the shield member.

FIG. 5 is a conceptual diagram illustrating a nuclear reactor configuration of a nuclear power generation facility.

[Explanation of symbols]

 10 Reactor Shielding Wall 11 Inner Wall Member 12 Outer Wall Member 13 Housing Space 14 Shielding Member 20 Reactor Pressure Vessel 30 Lead Compound Sphere (Shielding Member) 31 Surface Layer 32 Boron or Boron Compound 40 Iron Ball (Shielding Member) 50 Lead Ball (Shielding Member) )

Claims (3)

[Claims] 1. A cylindrical reactor shielding wall that covers the outside of a reactor pressure vessel, wherein a cylindrical inner wall member is provided around the reactor pressure vessel, and the cylindrical inner wall member is provided outside the inner wall member. Cylindrical outer wall members are arranged at predetermined intervals, and a spherical shielding member made of a radiation absorbing material is filled in the accommodation space formed between the inner wall member and the outer wall member. Reactor shielding wall structure characterized by the above. 2. The reactor shield wall structure according to claim 1, wherein the shielding member is formed such that a surface layer of lead has a predetermined thickness and contains boron or a boron compound therein. . 3. The shielding member is an iron ball and a lead ball having a predetermined size, both of which are mixed at a predetermined ratio and are filled in the accommodation space between the inner wall member and the outer wall member. The nuclear reactor shield wall structure according to claim 1.