JPS6136638B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a vacuum suction purification device for a nuclear power plant that removes dust, garbage, solid waste, etc. existing in a reactor containment vessel and a reactor building.

[Technical background of the invention and its problems]

How nuclear power plants have been conventionally cleaned will be explained with reference to the attached drawings. Figure 1 is a sectional view showing the entire reactor building, Figure 2
The figure is a sectional view showing details of the equipment arrangement within the reactor containment vessel.

A shielding wall 3, usually made of concrete, is provided on the outside of the reactor containment vessel 2 to house the nuclear reactor 1. A floor, a ceiling, and a wall made of concrete are connected to the shielding wall 3 and partitioned into a large number of spaces to form a room 4. Cooling equipment 5 during reactor operation is arranged in this room 4, and piping 6 connecting this cooling equipment 5, supports 7 supporting the piping 6, etc., trays 8, cables 9, air conditioning ducts 10, etc. are installed. ing.

On the other hand, inside the reactor containment vessel 2, piping 11 connected to the reactor 1, equipment 12, a floor structure 13 for supporting these, an air conditioning duct 10, etc. are arranged.

In a nuclear power plant with this kind of configuration, the ability to completely remove dust, garbage, and solid waste materials from inside the building and equipment during plant construction, and to load nuclear fuel materials, determines the operating rate and the ability to load nuclear fuel materials after plant operation. It is an extremely important factor that influences the amount of radioactive waste and radiation sources generated. In other words, dust, garbage, and solid matter scattered inside nuclear plant buildings and equipment can cause contamination of reactor cooling water after plant operation, the bottom of equipment, curved pipes, complex shapes of valves, and recesses. sedimentation of filth, radiation source, clogging of filters in reactor cooling water purification equipment, reduction in the lifespan of ion exchange resins,
Increase in waste generation, occurrence of internal exposure contamination of the respiratory system of periodic inspection personnel due to airborne dust in buildings during periodic inspections, and occurrence of radiation exposure contamination of periodic inspection personnel due to radioactivity of garbage and solid matter on the floor. I don't like it because it connects. In this way, in order to remove dust, garbage, and solid matter that are undesirable for plant operation, a dedicated worker first cleans the upper part of the room using cleaning tools such as a commercial vacuum cleaner, broom, motsup, and chemical rag. air conditioning duct 1
0, clean the piping 6, tray 8, cable 9 and support 7, then clean these air conditioning ducts 10,
The top and side surfaces of the equipment below the pipes 6, trays 8, and cables 9 are cleaned, and finally the floor of the building is cleaned and mopped to complete the work.
These cleaning tasks often involve equipment with complex shapes, cable trays with small gaps between stages, recesses and connections in cables and piping supports, and other locations that cannot be directly reached with cleaning tools, and all of these tasks are done manually. It's waddling. In particular, inside the reactor containment vessel 2, equipment is arranged in a complicated manner, and the equipment,
Because the piping supports are attached using shaped steel, the work space is small and it takes a lot of man-hours to complete a thorough cleaning.

In addition, dust, especially fine dust, rises up and spreads inside the building during cleaning, and over time, dust and fine dust accumulate again, causing the vacuum cleaner to exhaust the air. Because it is released directly into a closed room, the dust particles are diffused through exhaust air rather than being collected, making it difficult to clean them thoroughly.

Especially after a nuclear reactor is loaded with nuclear fuel material and starts operation, minute dust becomes a radiation source over time, so if you use a vacuum cleaner to clean it under these conditions, it will cause the same problem as mentioned above. As a result of the action, dust and fine dust that have become a source of radiation are suspended and diffused in the room, causing radiation exposure and contamination to the human body and respiratory system of workers. This is extremely undesirable from the standpoint of operation and worker entry control, as it spreads to areas with low radiation levels. Further, when a vacuum cleaner is used, dirt and dust are concentrated inside the vacuum cleaner, and the radiation dose also increases, which also causes radiation exposure contamination to workers.

For this reason, plant cleaning work after the reactor has started operating must be done completely manually, which requires a large amount of man-hours and costs. The increase in the amount of waste generated has inhibited the capacity of radioactive waste treatment facilities, which has also contributed to the lengthening of periodic inspection periods, leading to a decline in the operating rate of nuclear plants.

[Purpose of the invention]

The present invention has been developed in view of the above points, and is capable of cleaning nuclear power plants with high cleanliness in a short work time, suppressing the generation of unnecessary radioactive materials, and improving plant safety and operation rate. It is an object of the present invention to provide a vacuum suction purification device for a nuclear power plant, which can reduce radiation exposure of workers and reduce the amount of radioactive waste.

[Summary of the invention]

In the present invention, a vacuum suction pipe that has an opening that can be freely opened and closed and is deployed and connected to each divided room of the reactor containment vessel and the reactor building that surrounds the reactor containment vessel. an extension pipe which is removably connected to the opening and has a cleaning nozzle attached to its tip and a hand valve that can be opened and closed; a dust removal filter equipment connected to the end of the vacuum suction piping; Provided is a vacuum suction purification device for a nuclear power plant, which is provided with a vacuum suction device that is cascade-connected to a dust filter device, and connects the exhaust piping of the vacuum suction device to the intake port of an air purification device installed in the nuclear power plant. Then, while operating the vacuum suction equipment, open the opening of the required cleaning area, connect the extension pipe, attach the appropriately selected nozzle, open the hand valve, vacuum and clean the dirt and dust, and remove the suction exhaust. Furthermore, the above object is achieved by passing the air through an air purification device of a nuclear power plant and discharging it into an exhaust stack.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows an embodiment of the present invention, in which a vacuum suction pipe 17 is buried in the wall 15 and floor 16 of the reactor building 14 so as not to interfere with the reinforcement. The vacuum suction pipe 17 has an opening 1 for each divided room 4.
8 are placed in several places. This opening 18
Attach a blind cap (not shown) when not in use. On the other hand, a dust removal filter equipment 19 and a vacuum suction equipment 20 connected thereto are provided at appropriate locations within the building 14, and the dust removal filter equipment 19 is connected to a vacuum suction pipe 17 buried in the building. Furthermore, in the suction side duct part 22 of the air purification device 21 of the ventilation air conditioning equipment installed in the nuclear power plant,
The exhaust pipe 23 of the vacuum suction equipment 20 is connected. The exhaust pipe 23 may not be connected to the suction side duct portion 22 of the air purification device 21 at the plant construction stage, but may be provided so as to penetrate outside the building as the atmosphere discharge pipe 24. After the construction of the plant is completed and before loading nuclear fuel into the reactor and starting operation, the exhaust pipe 23 is connected to the suction side duct part 22 of the air purification device 21, and the vacuum suction equipment 20
The radiation-contaminated air emitted from the air purifier 21 is processed and then released into the atmosphere.

On the other hand, inside the reactor containment vessel 2, as shown in FIG. Let's set it up. The vacuum suction pipe 17 penetrates the reactor containment vessel 2 using a pipe penetration 25 and is connected to the vacuum suction pipe 17 on the building 14 side.

Next, as shown in FIG. 5, a flexible hose 26 of the required length made of flexible material such as rubber or synthetic resin is prepared, and one end of the flexible hose 26 is connected to the vacuum suction pipe 1.
A coupling ring 27 that can be easily connected to the opening 18 of the cleaning nozzle 29 is attached to the other end, and an insertion cap 28 of the cleaning nozzle 29 is attached to the other end. The cleaning nozzle 29 is designed to facilitate cleaning depending on the area to be cleaned, for example, one with a beak-shaped tip as shown in FIG. 5, or one with a cup-shaped tip as shown in FIG. Items of various shapes are prepared.

The insertion cap 28 has a tapered inner diameter,
It can be easily inserted into the connecting end of the cleaning nozzle 29 having a tapered outer diameter and can be fixed and removed. Furthermore, the insertion cap 28 is provided with a hand valve 30 that controls opening and closing of ventilation.

The dust removal filter equipment 19 is configured so that a deteriorated filter can be replaced with a new filter using a filter replacement device. Replacement filters after plant operation may contain radioactive materials, so they will be disposed of using radioactive waste treatment equipment.

Next, the operation of this embodiment will be described.

When using this device, please use the vacuum suction equipment 2.
0, select an appropriate opening 18 of the area to be cleaned, remove the blind cap, select an appropriate cleaning nozzle 29, and connect the attached flexible hose 26. Therefore, the hand valve 30 is opened and the cleaning work is performed while operating the flexible hose 26.

After the dirt, dust, etc. are sucked by the cleaning nozzle 29, the flexible hose 26, vacuum suction piping 17, dust removal filter equipment 19, vacuum suction equipment 20, exhaust piping 23, suction side duct section 22,
The air passes through the air purification device 21 in this order and is subjected to suction treatment.

In the construction stage of the plant, the suction material passes through the vacuum suction equipment 20 described above and is then discharged into the atmosphere through the atmosphere discharge pipe 24.

〔Effect of the invention〕

As is clear from the above description, the reactor cooling water of the present invention can be kept clean during operation, and the life of the consumable parts of the cooling water purification device can be extended. In addition, it is possible to collect garbage, dust, etc. in the reactor containment vessel and reactor building without dispersing it, thereby preventing workers from being exposed to radiation through inhalation, and preventing waste from being contaminated with radiation. The generation of cleaning tools can be reduced. Furthermore, since the collected garbage, dust, etc. are concentrated in one specific location, it is possible to prevent exposure to radiation due to an increase in radiation intensity due to concentration of garbage, dust, etc. in the vicinity of the worker.

As a result of the above-mentioned effects, the safety of the plant during operation is improved, the regular inspection period is shortened, and as a result, the operating rate of the nuclear power plant is improved, and other remarkable effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the entire reactor building, FIG. 2 is a sectional view showing the equipment arrangement inside the reactor containment vessel, and FIG. 3 is a sectional view showing the reactor building portion of an embodiment of the present invention. FIG. 4 is a cross-sectional view showing the reactor containment vessel portion, FIG. 5 is a cross-sectional view showing details of the extension pipe portion, and FIG. 6 is a cross-sectional view showing an example of the cleaning nozzle. 2... Reactor containment vessel, 4... Room, 8... Opening, 14... Reactor building, 17... Vacuum suction piping, 19... Dust removal filter equipment, 20... Vacuum suction equipment, 21... ... Air purification device, 22 ... Suction side duct section, 23 ... Exhaust piping, 26 ... Flexible hose, 29 ... Cleaning nozzle, 30 ...
Hand valve.

Claims (1)

[Claims] 1. A reactor containment vessel and a vacuum suction pipe that is deployed and connected to each divided room of the reactor building surrounding the reactor containment vessel and has an opening that can be freely opened and closed, and the opening an extension pipe that is detachably connected to the vacuum suction pipe, has a cleaning nozzle attached to its tip, and has a hand valve that can be opened and closed; a dust removal filter equipment that is connected to the end of the vacuum suction pipe; Vacuum suction purification of a nuclear power plant, characterized in that a vacuum suction equipment is cascade-connected to the equipment, and the exhaust piping of the vacuum suction equipment is connected to the intake port of an air purification device installed in the nuclear power plant. Device.