JPS63284495A - Transient storage equipment for radioactive drain water of nuclear power plant - Google Patents

Abstract

PURPOSE:To reduce and rationalize a nuclear reactor building by setting the floor level of the lowest floor of an adjacent building lower than the floor level of one story above the lowermost floor of the nuclear reactor building and providing a transient storage sump for radioactive drain water to the floor of the lowermost story of the adjacent building. CONSTITUTION:The sump 7 for transient storage of the radioactive drain water is provided on the floor 5 of the lowermost story of the adjacent building 3 and drain pipings 4 for guiding the radioactive drain water are disposed from the upper floors except the lowermost story of the reactor building 1 down to the sump 7. The normal system radioactive drain water generated in a secondary stowage facility 2 on the floor above >=1 stories above the lowermost floor of the building 1 is gathered in the pipings 4 and falls by gravity through the pipings 4 so as to be stored in the above-mentioned sump 7. Traps 11 where the radioactive drain water stagnates transiently are provided to the mid-points of the pipings 4 to prevent intrusion of the air in the building 3 into the facility 2. The reactor building is thus reduced and rationalized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to equipment for temporarily storing radioactive drain water generated on the upper floor of a reactor building of a nuclear power plant.

[Conventional technology]

(refers to a containment facility that forms a space in the operating center of the facility that is controlled so that the internal pressure is negative relative to the outside air).
and a secondary containment facility area provided around the secondary containment facility on the same foundation mat. The secondary containment facility houses the reactor containment vessel, fuel handling equipment, reactor auxiliary system, etc., and also houses the emergency core cooling facility (hereinafter referred to as ECC8) on the lowest floor. The secondary containment facility area houses waste treatment equipment, electrical equipment, a central control room, etc.

Radioactive drain water generated on the upper floors (excluding the bottom floor) of the secondary containment facility has traditionally been stored in a radioactive drain water temporary storage sump installed on the lowest floor of the secondary containment facility area of the reactor building. I try to do that. This means that if the radioactive condensate temporary storage sump is installed on the bottom floor of the secondary containment facility in the reactor building, in the unlikely event that it overflows, the sump will be stored on the bottom floor of the secondary containment facility. This is because there is a risk of damaging the integrity of ECC8.

Although there is Japanese Patent Application Laid-open No. 55-69100 as a prior art regarding a radioactive drain water transfer facility, it does not describe the secondary containment facility or ensuring the integrity of the ECC8.

[Problem that the invention seeks to solve]

The above conventional technology installs a temporary storage sump for radioactive drain water generated on the upper floor of the secondary containment facility of the reactor building on the lowest floor of the secondary containment facility area of the reactor building. It is fully viable if it consists of a containment facility and a secondary containment facility area around it.

By the way, in recent years, in order to reduce the size and volume of the reactor building and reduce plant construction costs, the secondary containment facility area has been removed from the reactor building, and the bottom floor of the reactor building where ECC8 is installed has been A rationalized reactor building consisting only of secondary containment facilities is being considered. However, in the case of such a rationalized reactor building, the radioactive drain water temporary storage facility according to the prior art is installed on the upper floor of the secondary containment facility of the reactor building. The location was an issue, and it was not suitable for plant rationalization design that would reduce the size and volume of the reactor building.

The purpose of the present invention is to transfer radioactive drain water generated on the upper floor of the secondary containment facility to the ECC 8 in a reactor building where the lowest floor of the reactor building where the ECC 8 is installed is composed only of the secondary containment facility. The objective is to provide equipment for temporary storage without the impact of nuclear power, thereby contributing to the rationalization and downsizing of nuclear reactor buildings.

[Means for solving problems]

The present invention provides a nuclear power plant having a reactor building whose lowest floor, which houses emergency core cooling equipment, consists only of secondary containment facilities, and an adjacent building adjacent to the reactor building.
The floor level of the lowest floor of the adjacent building is the same as the lowest floor of the reactor building9.
A temporary storage sump for radioactive condensate water is installed on the floor of the lowest floor of the adjacent building, lower than the floor level of the first floor above, and radioactive condensate water generated on the floors above the lowest floor of the reactor building is collected as above. A drain pipe leading to a temporary storage sump is provided, and a trap in which radioactive drain water temporarily accumulates is provided in the middle of the drain pipe.

[Effect]

Since the floor level one floor above the bottom floor of the reactor building and the floor level of the bottom floor of the adjacent building are in the above relationship, the radioactivity generated on the floor above the bottom floor of the reactor building is The drain water falls by gravity within the drain pipe and is stored in a temporary radioactive drain water storage sump provided on the lowest floor of the adjacent building.

Since the trap is provided in the middle of the drain pipe, the drain water collected there prevents air from an adjacent building from entering the secondary containment facility of the reactor building.

〔Example〕

An embodiment of the present invention will be explained below with reference to FIG. The reactor building 1 consists of a secondary containment facility (indicated by a two-dot chain line in the figure), which forms a space whose interior is always controlled to have a negative pressure with respect to the outside air, and a space 8 outside the secondary containment facility. has been done. The bottom floor of reactor building 1 consists only of secondary containment facilities, and ECC8 is installed on this bottom floor, and on floor 5 of this bottom floor, radioactive drain water from the ECC8 equipment room is temporarily stored. A reservoir sump 9 is provided.

Adjacent to the reactor building 1 described above, an adjacent building 3 (for example, a turbine 4 building, a waste treatment building, or a control building) that houses equipment and equipment necessary for a nuclear power plant is installed on a separate foundation mat. ing. The level of the lowest floor 6 of this adjacent building is set lower than the level of the floor 10 one floor above the lowest floor 5 of the reactor building 1.

A sump 7 for temporary storage of radioactive drain water is installed on the floor 6 of the lowest floor of the adjacent building 3, and the reactor building 1
A drain pipe 4 is provided to guide radioactive drain water from the upper floors other than the lowest floor. The radioactive drain water generated in the secondary containment facility 2 at one or more floors above the bottom floor of the reactor building 1 is collected in the drain pipe 4 and falls by gravity through the drain pipe 4. The radioactive drain water is then stored in the temporary storage sump 7 installed on the lowest floor 6 in the adjacent building 3.

In the middle of the drain pipe 4 is a U-shaped part (so-called trap) 11 where radioactive drain water temporarily accumulates.
The air in the adjacent building 3, which is not maintained at a negative pressure with respect to the outside air, is transferred to the secondary containment facility 2 of the reactor building 1, which is maintained at a negative or positive level due to the drain water accumulated there. Prevent entry through the drain piping.

〔Effect of the invention〕

According to the present invention, in a nuclear power plant where the lowest floor of the reactor building consists only of secondary containment facilities in order to reduce the construction cost of the reactor building, the The radioactive drain water generated on the upper floors of the reactor building can be temporarily stored without affecting the ECC8, which contributes to the downsizing and rationalization of the reactor building and ensuring its integrity. Specifically, while the volume of a conventional reactor building, which has an internal area of the secondary containment facility 2 around the lowest floor of the reactor building, is approximately 250 x 10"m, the present invention The volume of the furnace building was reduced by approximately 30 inches to approximately 170X.
10'-.

[Brief explanation of the drawing]

FIG. 1 is an elevational sectional view showing an example of the practical application of the present invention. 1... Reactor building 2... Secondary containment facility 3...
・Adjacent building 4... Drain piping 7... Radioactive drain water temporary storage sump 11... Trap.

Claims (1)

[Claims] In a nuclear power plant that has a reactor building where the lowest floor housing emergency core cooling equipment consists only of secondary containment facilities and an adjacent building adjacent to the reactor building, the lowest floor of the adjacent building is The floor level is set lower than the floor level one floor above the bottom floor of the reactor building, and a temporary radioactive drain water storage sump is installed on the bottom floor of the adjacent building. A radioactive nuclear power plant characterized in that a drain pipe is provided to guide the radioactive drain water generated on the upper floor to the temporary storage sump, and a trap in which the radioactive drain water temporarily accumulates is provided in the middle of the drain pipe. Temporary storage equipment for drain water.