JPS58161892A - Fire resistant radiation shielding structure - 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 radiation shielding structures such as wall holes and floor holes.

Conventionally, radiation shielding for pipes such as wall holes, floor holes, and through holes of penetrating members such as electric wire cables has been carried out by filling the gaps with lead hair, lead balls, lead blocks, etc. However, with this method, the lead shield melts and flows out under high-temperature conditions during a fire. Even after the fire has ended, the radiation shielding ability cannot be maintained without reducing the radiation shielding effect by filling only with lead. If concrete is poured in the same way as a wall, it will not be possible to handle the need to pass additional through-holes at a later date, and if a large number of pipes, core wires, and cables are passing through the through-holes. It is difficult to fill each narrow gap with barrier material.

The purpose of the present invention is to eliminate the drawbacks of the prior art described above, and to provide a radiation shielding structure that does not melt even under high temperature conditions such as a fire, and maintains sufficient radiation shielding ability even after a fire has occurred. It's true.

In other words, the gist of the present invention is to fill the wall surface area on the side where there is a high possibility of fire occurrence with a metal such as steel that does not melt even at the temperature of a fire, and to fill the central part of the wall that does not reach the melting temperature even by heat transfer during a fire. The reason is that the structure is filled with lead, which has a high ability to block radiation.

Atmospheric conditions for general fires are: J Engineering SA 1
504 (1975) ffi, it is assumed that the temperature will reach 1095°C in 4 hours after a fire occurs, and if the fire protection ability is to be maintained under this atmospheric temperature condition,
If only lead, which has a melting point of around 6215°C, is used, the lead near the wall surface will melt and it will be difficult to keep it in its current form.

Therefore, this problem can be solved by filling the portion close to the wall surface with a material having a melting point of 1100° C. or higher, such as steel.

A specific example of this invention will be explained with reference to the drawings.

A penetrating member such as a pipe or an electric wire A2 or an electric wire or a cable O is passed through the through hole 11 of the radiation shielding wall 1, and a support 6 is placed on the wall surface. Inside the through hole 11, steel powder 4 having a melting point of 1100° C. or more is used as a stiffening material in a portion close to the wall surface, and lead 5 is used as a stiffening material in a portion corresponding to the center of the wall.

It is preferable to use powdered or granular materials for iron@4 and lead5 to improve the filling level.

For example, in the case of steel, copper powder of 46 mesh or less is suitable depending on the filling method and degree. Also, in the case of lead, the diameter is 1.
Lead balls and lead grains with a size of 0 or less are good. In addition, if the number of pipes, core tubes, core wires, and cables to be penetrated into the wall hole is small and the spatial arrangement structure of the hole cross section is simple, a block-like shape for both steel and lead is easy to work with. Further, iron powder, lead particles, etc. may be placed in a convenient bag and filled into the gap. However, since the purpose of the bag in this case is to facilitate the filling operation, there is no functional problem even if the bag is charred in the event of a fire and does not leave any trace of the bag's shape.

In addition, it is desirable to determine the thickness of each of the steel materials and lead materials by calculating the melting temperature of lead and the shielding effect during lamination by heat transfer calculations, shielding calculations, etc.

The steel material 4 to be filled is the steel material 4 to be filled when passing through an electric cable or bus bar that carries a large amount of power.
It is desirable to prevent iron loss by using a non-magnetic material such as stainless steel. Depending on the type of radiation to be suppressed, it may also be desirable to use a combination of materials such as graphite and silica rock.

In addition, as shown in FIG. 2, it is desirable that the piping, electric conduit 2, electric wire, and cable 6 be offset or spirally wound to prevent streaming of radiation in the gap between them and the radiation shielding material.

In addition, the shape of the filling material is the shape of the penetrating bodies 2 and 6,
The size should be appropriate depending on the number and size of the pieces, and it is also possible to have a structure in which the gaps are filled by appropriately combining blocks, plates, balls, grains, powder, etc.

By implementing the structure of the present invention, the following effects can be obtained.

(1) A high melting point barrier material is placed on the part corresponding to the wall surface.
In addition, since lead insulation is used in the center of the wall, good radiation protection performance can be obtained even when exposed to high temperatures such as fire.

(2) Since powder or granular material is used as the radiation shielding material, filling work is easy and it is easy to add or remove penetrating members.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the fire-resistant radiation shielding structure of the present invention, and FIG. 2 is a sectional view showing another embodiment of the fire-resistant radiation shielding structure of the present invention. 1: Radiation blocking wall, 2: Piping, electric conduit, 6: Electric wire, cable, 4: High melting point blocking material, 5: Lead particles, 6: Support, 11: Through hole.

Claims (1)

[Claims] 1. In the shielding structure of the portion where the penetrating member penetrates the wall for radiation shielding, a shielding material made of lead particles is provided in a portion corresponding to the center of the wall, and at least one side of the shielding structure is provided with a shielding material made of lead particles. A fire-resistant radiation barrier structure characterized by a high melting point barrier material being provided on the portion corresponding to the wall surface. 2. The fire-resistant radiation barrier structure according to item 1, wherein the high melting point barrier material is steel powder.