JPS6124000A - Method of treating leaking liquid - 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 <Industrial Application Field> The present invention relates to a method for treating leaked liquid, and particularly to a method effective for treating radioactive wastewater, oil, and the like.

<Prior art and its problems> In order to remove liquid leaked from a given container or piping system, the liquid is usually absorbed using fiber material such as cloth or porous material such as sponge. Methods such as pouring into drainage (liquid) channels such as side gutters using a mop etc. have been adopted. All of these methods involve directly handling the liquid spilled by humans, so if the liquid is toxic or contains radioactive materials, such as circulating water at a nuclear power plant, the work becomes extremely difficult. It becomes dangerous.

In this regard, water contaminated with radioactive materials (hereinafter simply "
An example of handling contaminated water (referred to as "contaminated water") will be explained below.

At nuclear power plants, accidents within the system have an extremely large impact on the surrounding environment, so multiple safety measures are taken, but it is impossible to completely eliminate contaminated water leakage accidents. Close to. Naturally, leakage accidents that occur under such conditions are unexpected, and it is not possible to take concrete measures in advance.

Therefore, when an accident occurs, it is necessary to deal with the situation accordingly, which requires manual processing.

If contaminated water leaks, it is most important to minimize the leakage of contaminated water and to prevent the progress of contamination due to contaminated water. That is, the leakage of contaminated water should be stopped as soon as possible, and the leaked water should be recovered. Previously, workers wearing protective clothing sealed the area where contaminated water was generated using plastic sheets, etc., to prevent radioactive materials from escaping elsewhere.
Methods are in place to recover leakage water. In the case of a small amount of leakage, use a rag (2) to collect it, but since the contaminated water will directly adhere to the protective clothing, there is a risk of exposure when removing the protective clothing, making the work quite dangerous. . Since the contaminated water itself remains in a liquid state, there is a risk of re-contamination due to spillage during transportation. Furthermore, there is a risk that pollutants will be dissipated into the atmosphere due to evaporation or the like.

As mentioned above, once a leakage accident occurs, the work that follows involves handling the leaked water directly by hand, which is extremely dangerous and requires a long time, which may lead to the spread of contamination.

In addition to contaminated water due to radioactive substances, leakage of chemicals from various chemical plants, oil leakage from petroleum plants, thermal power plants, etc. also have the same problems as described above, although there are differences in degree.

<Means to Solve the Problems> The present invention was constructed in view of the problems of the conventional method described above, and is designed to prevent the spread of contamination sources by making leaked liquid non-fluid, and to facilitate recovery. This is the way to do it.

<Summary of Means> In short, the present invention sprays a substance that makes the liquid immobilized on the leaked liquid, and if necessary, at the same time or prior to this, a drug having a surfactant effect is supplied to the leaked liquid to remove the substance. This method improves the affinity between the leaked liquid and the leaked liquid.

<Examples> Examples of the present invention will be described below. The leaked liquid will be explained using contaminated water as an example.

- If contaminated water leaks, immediately work to minimize the leakage, and once the leakage has stopped, spray a superabsorbent agent on the leaked water. A common feature of super-absorbent agents is that when they come into contact with water, they instantly absorb water, swell, and gel the water-metal body, and their water absorption is approximately 800%.
~1000 times, 800 to 100 with super water absorbent of 17
It can absorb 0 t of water. Another feature is that once water is absorbed, it will not release water even if some pressure is applied. Furthermore, superabsorbent agents are classified into three types: starch, cellulose, and synthetic polymer. Cellulose agents are fibers, and the others are powders. However, in this case, the sprayed superabsorbent agent and leaked water may not be partially miscible.

Therefore, at the same time as or before spraying the superabsorbent agent, a drug (particularly preferably a liquid one) having a surfactant effect on leaked contaminated water is added.

The sprayed superabsorbent agent mixes with the contaminated water in a very short time and turns the contaminated water into a gel.

In this case, for example, if contaminated water is attached to an irregular surface that is not smooth, such as a wall surface, gelling it in this area may actually make later removal work difficult or incomplete. In this case, only the decontamination agent is first sprayed to drain the contaminated water onto an area that is easy to treat, such as the floor, and then gelled.

Citric acid is an effective method for removing cationic contamination.
A complexing, chelating, or sequestering agent such as ethylenediaminetetraacetic acid, (EDTA) is used. Using a complexing agent as an example, a dilute solution of the complexing agent forms a stable complex with the metal, and this complex is very stable even in solution. Therefore, in the case of cationic contamination, complexing agents, chelating agents, sequestering agents, etc. are supplied to the contaminated water simultaneously or separately from the above-mentioned agents with surfactant effects, and simultaneously or separately from the superabsorbent agent spraying. It's good to do that.

In this case, in addition to the above chemicals, if you spray an electrical insulating material (liquid or powder) on the glass, the leaked water or its gel will become an insulator or at least a poor conductor, so you can prevent electrical leakage caused by the leaked liquid. It can be prevented.

It is not necessary to limit the collection of contaminated water to one time; once the gel-like material has been collected, it is further washed, and the washing solution is roughly heated to gel and then collected. By repeating this process several times, the contaminated water is completely removed.

FIG. 1 shows an apparatus for carrying out the method according to the invention. Reference numeral 1 in the figure is a moving trolley, which is self-propelled by a motor 3 operated by a power source 2, and is configured to be steerable by remote control. Reference numeral 4 is a storage tank in which a superabsorbent agent 5 is stored, and a perforated plate 6 is arranged at the bottom of the storage tank. Reference numeral 7 denotes a cylinder having an injection medium, and in the illustrated case, it is configured to supply 002 as the injection medium. Reference numeral 8 denotes a CO2 supply pipe, the tip of which opens near the nozzle 9 in the storage tank 4. The nozzle 9 base 7i1 is normally closed by a thin film (rupture disk) 10 made of gold maple or the like, and is broken by the injection force during Co2 injection. Reference numeral 24 denotes a tank that stores the aforementioned complexing agent, quinlating agent, sequestering agent, and other agents capable of retaining radioactive substances (hereinafter referred to as "retention agent"), and 25 denotes this tank. and a retention agent supply pipe connecting the CO2 supply pipe, and 26 is a venturi for mixing retention agent provided in the pipe.

Next, reference numeral 11 is a tank in which a decontamination agent is stored, 12 is a decontamination agent supply pipe that connects this decontamination agent tank and the Co2 supply pipe 8, and 14 is a venturi.

The above describes a method for treating leaked liquid using this device.

Note that the leaked liquid is contaminated water containing radioactive materials. If contaminated water leaks, immediately stop the leak and collect the leaked contaminated water. In this case, the entire device is self-propelled to the leakage site by a remote-controlled trolley 1. The operator controls this device from a safe location, but in this case, the operator checks the surroundings using the television camera 1γ and drives from the beginning. All of the work described below will be performed remotely to ensure the safety of the operators. When the main body of the apparatus arrives at the leakage site, the leakage state is confirmed with a television camera 17. Operators determine whether to spray the decontamination agent (cleaning agent) and retention agent at the same time as the superabsorbent agent or before spraying the superabsorbent agent, depending on the type of leaked water and the location of the leakage.

First, an example will be explained in which the superabsorbent agent is injected and supplied simultaneously with the superabsorbent agent. While the valves 18 and 27 are opened to enable the supply of decontamination agent and retention agent, the valves 19 and 29 are opened to inject Co2 as a dispersion medium.

A portion of the Co2 is supplied to another Co2 supply branch pipe 20. Pressure reducing valve 2
8 into the air chamber 21 at the bottom of the perforated plate 6, and flows into the superabsorbent layer through the small holes of the perforated plate 6, fluidizing the layer. On the other hand, the CO2, retention agent, and decontamination agent supplied from the Co2 supply pipe 8 are injected from the nozzle 8a toward the thin plate 10, crushing the thin plate 10, and fluidizing the superabsorbent agent 5.
is injected toward the leaked water through the nozzle 9. In this case, the operator monitors the jetting state with a television camera, and adjusts the jetting direction of the nozzle 9 using the nozzle drive device 23 to evenly spray the superabsorbent over the leaked water.

Next, when spraying the retention agent and decontamination agent before spraying the super absorbent agent, leave valves i8 and 27 open, valve 19.30 open, and valve 29 open.
When closed, the retention agent and decontamination agent are injected and dispersed by Co2 from the nozzle 31 toward the leaked water.

By performing the above measures, the leaked water and the superabsorbent agent layer are mixed in a very short time, and the leaked water is solidified into a gel-like state. Afterwards, collect the gelled leaked water. By forming a gel in this manner, it is possible to prevent contaminated water from flowing away, and to minimize the release of radioactive substances into the environment. Furthermore, there is no risk of leaking water spilling during transportation, and handling is easy and safe.

The above description has been made using the case of treating contaminated water as an example, but the present invention is not limited to this, and can also be effectively used to treat chemicals leaked from chemical plants, oil leaked from petroleum plants, and the like. In addition, even if a fire occurs, it can be used to recover the remaining liquid after extinguishing the fire.

Effects> By carrying out the present invention, it is possible to minimize the diffusion of leaked liquids such as contaminated water, various chemicals, and oil, and also to easily and safely recover them.

[Brief explanation of the drawing]

FIG. 1 is a detailed view of a superabsorbent dispersing device for carrying out the method according to the invention. 5...Super water absorption agent, 7...Co2 gas cylinder, 11
...decontamination agent tank, 24...retention agent tank.

Claims (1)

[Claims] 1. A leaked liquid treatment method, which comprises spraying a superabsorbent agent on the leaked liquid to turn the leaked liquid into a gel. 2. The leaked liquid treatment method according to claim 1, characterized in that, in addition to the superabsorbent agent, a retention agent that retains a drug having a surfactant effect and/or a radioactive substance is sprayed. 3. The leaked liquid treatment method according to claim 20, characterized in that, prior to spraying the superabsorbent agent, a drug having a surfactant effect and/or a retention agent is sprayed on the leaked liquid. 4. The method for treating leaked liquid according to any one of claims 1 to 3, characterized in that in addition to each of the chemicals, an electrical insulating material is sprayed to prevent electrical leakage caused by the leaked liquid.