JPH0228600A - Wall surface cleaning device - Google Patents

Abstract

PURPOSE:To prevent the radiation exposure of an operator and the amount of radioactive waste from increasing and to clean a nuclear reactor well and a tank by spouting the reservoired liquid in a storage tank to a wall surface and cleaning the wall surface. CONSTITUTION:The annular part 3a atop a flexible hose 3 and a flexible hose 8 for supplying water are put in the storage tank 4. Then a pressure pump 2 is put in operation and the water in the storage tank 4 is filtered by a filter 9 and then spouted from the outside injection nozzle 5 and inside injection nozzle 6 of the annular part 3a. At this time, the high pressure water sent out by the pressure pump 2 is spouted from the outside injection nozzle 5 and inside injection nozzle 6 at the same time and the annular part 3a stops where their force are balanced, thereby removing contaminants on the wall surface 4b with the water spouted from the outside injection nozzle 5. Then when the drain valve 4c of the storage tank 4 is opened in this state, the water in the storage tank 4 is discharged and the water level 4a decreases, so the annular part 3a also moves down gradually to clean a lower wall surface 4b in order.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a wall cleaning device, and in particular, a wall cleaning device suitable for cleaning walls such as reactor wells and tanks of nuclear power plants. Regarding.

(Prior Art) Generally, in a nuclear power plant, radioactive substances adhere and accumulate on the walls of reactor wells, tanks, etc. over time. These deposits can become a source of radiation exposure for workers, and can scatter outside, causing the spread of contamination. For this reason, nuclear power plants have traditionally carried out cleaning operations to remove such deposits.

Traditionally, when performing this type of cleaning, after draining the container,
Either a worker wipes it with a rag, or water is supplied from the outside and jet cleaning is used.

(Problem to be Solved by the Invention) As mentioned above, conventionally, when cleaning reactor wells, tanks, etc., after draining water, workers either wiped it with a rag or poured water from outside. It is carried out by a method of supplying and jet cleaning.

However, among these methods, wiping and cleaning by workers has problems such as the workers being exposed to radiation during the work, the work being time consuming and the plant inspection process being prolonged, and the used rags being disposed of as radioactive waste. This is a contributing factor to the increase in the amount of waste accumulated within the plant.

On the other hand, jet cleaning with water reduces the radiation exposure of workers, but poses problems such as secondary contamination due to splashing of the cleaning water and an increase in the load on the liquid waste treatment system due to the used water.

The present invention has been made in response to such conventional circumstances, and is a wall surface that allows cleaning of reactor wells, tanks, etc. without increasing radiation exposure of workers or increasing the amount of radioactive waste. The purpose is to provide a cleaning device.

[Structure of the Invention] (Means for Solving the Problems) That is, the wall surface cleaning device of the present invention cleans the stored liquid near the surface of the stored liquid stored in the storage tank along the wall surface in the storage tank to be cleaned. It is characterized by comprising an injection nozzle which is provided in a floating state and injects the stored liquid toward the wall surface, a pump that supplies the stored liquid to the injection nozzle, and a filter for purifying the stored liquid. shall be.

(Function) In the wall surface cleaning device of the present invention having the above configuration, the wall surface is cleaned by jetting out the stored liquid in the storage tank toward the wall surface. Reactor wells, tanks, etc. can be cleaned without increasing the amount of material.

(Example) Hereinafter, details of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a wall cleaning device according to an embodiment of the present invention, in which a flexible hose 3 is connected to the outlet side of a pressurizing pump 2 mounted on a moving cart 1. As shown in FIG.

As shown in FIG. 2, an annular portion 3a formed in an annular shape to match the shape of the storage tank 4 is connected to the tip of the flexible hose 3. A large number of outer injection nozzles 5 and inner injection nozzles 6 are arranged on the outside and inside along the line. Further, as shown in FIG. 3, this annular portion 3a is provided with a floater 7, and when the annular portion 3a is put into water, the outer injection nozzle 5 and the inner injection nozzle 6 are inserted into the storage tank 4. It is configured to be located underwater substantially parallel to the water surface 4a.

On the other hand, a flexible hose 8 is provided on the artificial side of the pressure pump 2 for supplying water in the storage tank 4 to the pressure pump 2.
is connected, and this flexible hose 8 is provided with a filtration filter 9.

In the wall cleaning device of this embodiment having the above configuration, the annular portion 3a at the tip of the flexible hose 3 and the flexible hose 8 for supplying water are placed into the storage tank 4. Then, the pressurizing pump 2 is activated, and after the water in the storage tank 4 is filtered by the filtration filter 9, it is ejected from the outer injection nozzle 5 and the inner injection nozzle 6 of the annular portion 3a.

At this time, the high-pressure water sent out by the pressure pump 2 is simultaneously injected from the outer injection nozzle 5 and the inner injection nozzle 6, and the annular portion 3a is located at a position where these forces are balanced (a position a predetermined distance from the wall surface 4b). Then, the water sprayed from the outer spray nozzle 5 removes contaminants from the wall surface 4b.

If the drain valve 4C of the storage tank 4 is opened in this state, the water in the storage tank 4 will be drained and the water level 4a will drop.
Along with this, the annular portion 3a also gradually moves downward, and the lower wall surface 4b can be sequentially cleaned.

That is, the wall surface cleaning device of this embodiment has the following effects. First, since the distance to the wall surface 4b is kept constant by the opposing outer spray nozzle 5 and inner spray nozzle 6, the wall surface 4b can be cleaned with a constant cleaning power. In addition, since the water in the storage tank 4 is used for cleaning through the filtration filter 9, no waste is generated due to cleaning, and cleaning can be done at the same time as the water in the storage WI 4 is discharged, so the plant inspection period This makes it possible to significantly shorten the time and reduce the amount of waste generated. Furthermore, since the injection from the outer injection nozzle 5 and the inner injection nozzle 6 is performed under the water surface, secondary contamination due to water scattering does not occur.

[Effects of the Invention] As explained above, according to the wall cleaning device of the present invention,
Reactor wells, tanks, etc. can be cleaned without increasing radiation exposure for workers or increasing the amount of radioactive waste.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a wall cleaning device according to an embodiment of the present invention, FIG. 2 is a top view showing the main parts of the wall cleaning device shown in FIG. 1, and FIG. 3 is a wall cleaning device shown in FIG. 1. FIG. 2 is a cross-sectional view showing the main parts of the device. 2...... Pressure pump 3... Flexible hose (population side) 3
a...Annular part 4...Storage tank 4a...Water surface 4b...Wall surface 4C...Drain valve 5... ......Outer injection nozzle 6...Inner injection nozzle 7...Floater 8...Flexible hose (outlet extension 1) ) 9...Filtration filter applicant: Japan Atomic Energy Corporation, applicant
Toshiba Corporation

Claims (1)

[Claims] (1) An injection nozzle that is installed in a floating state in the stored liquid near the surface of the stored liquid stored in the storage tank along the wall surface in the storage tank to be cleaned, and injects the stored liquid toward the wall surface; A wall cleaning device comprising: a pump for supplying the stored liquid to the injection nozzle; and a filter for purifying the stored liquid.