JPS60151586A - Treater for suppression pool water - 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 [Technical Field of the Invention] The present invention relates to a suppression pool water treatment device for cleaning and removing impurities from suppression pool water in a boiling water nuclear reactor.

[Technical background of the invention]

Generally, a pressure suppression type reactor containment vessel is employed in a boiling water reactor.

Figure 1 shows an example of this reactor containment vessel.
It is formed by a dry well 1, an annular suppression pool 3, and a number of radially arranged vent pipes 2 connecting the two.

A predetermined amount of suppression pool water 3a is always stored in the suppression pool 3.

In the event of an emergency, the primary system steam released in the dry well 1 due to a reactor-primary system rupture is guided into the suppression pool 3 through the vent pipe 2, and the steam is condensed in the suppression pool water 3a. The system is designed to condense water and suppress the pressure rise inside the reactor containment vessel.

[Problems with background technology]

In addition to the above-mentioned uses, the suppression pool water 3a is used as emergency cooling water in the event of a loss of coolant accident, or for removing residual heat when a nuclear reactor is shut down.

In addition, the suppression pool 3 is made of carbon steel, and its inner surface is coated with anti-rust coating.
Furthermore, a rust preventive material may be added to the suppression pool water 3a.

However, due to long-term use, insoluble corrosion products, rust preventive materials, etc. tend to accumulate in the suppression pool water 3a, and furthermore, the accumulated substances contain radioactive substances.

Therefore, there is a risk that workers will be exposed to radiation during periodic inspections in the suppression pool 3, and there is also a risk that radioactive materials will be diffused into the atomic couplant if the suppression pool water 3a is sent to other uses.

Therefore, conventionally, the suppression pool water 3a is washed,
It was desired to remove impurities and the like.

[Purpose of the invention]

The present invention has been made in view of these points, and provides a suppression pool water treatment device that can reliably remove impurities in suppression pool water, has a large processing valley lid, and is stable in operability. The purpose is to provide.

[Summary of the invention]

The first invention of the suppression pool water treatment device of the present invention includes a hollow filter mechanism for removing insoluble corrosion products from the suppression pool water, and a rust preventive material from the fluid flowing out of the hollow filter mechanism. It is formed by providing a reverse osmosis membrane mechanism for removing ionic substances and a desalination tower mechanism for removing ionic substances from the fluid flowing out of the reverse osmosis membrane mechanism to produce clean water.

The second invention is formed by further providing a crystallization coprecipitation mechanism for precipitating the rust preventive material removed by the reverse osmosis membrane mechanism.

A third invention further provides the second invention, in which the precipitate precipitated by the crystallization coprecipitation mechanism is transferred to a hollow fiber filter mechanism and removed, and the precipitate is concentrated together with the insoluble corrosion products. It is formed by providing a sediment transfer mechanism to allow the precipitation to be carried out.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 2 and 3.

FIG. 2 is a block diagram showing an outline of the present invention, and simultaneously shows the first to third inventions. In the same figure, the suppression pool water 3a in the suppression pool 3 is Therefore, it is sucked into the hollow filter mechanism B. This hollow fiber filter mechanism B removes insoluble corrosion products from the suppression pool water 3a.

Thereafter, the rust preventive material in the suppression pool water 3a is removed by the reverse osmosis membrane mechanism C. After that, ionic substances are removed by the desalination tower a, and the suppression pool water 3
a is subjected to cleaning treatment. The clean water is then collected by a suitable collection mechanism E and returned to the suppression pool 3.

The first invention is formed by the hollow system filter mechanism B1 reverse osmosis membrane mechanism C1 demineralization tower machine.

In the second invention, a crystallization coprecipitation mechanism F for precipitating the rust preventive material removed from the suppression pool water 3a by the reverse osmosis membrane mechanism C is further provided.

The rust preventive material precipitated in this crystallization coprecipitator mF may be discharged by an appropriate means. The third invention is a crystallization coprecipitator 4
A precipitate transfer device 4#G is further provided to guide the rust preventive material precipitated by the filter 14F to the hollow filter mechanism B. Then, in the hollow filter machine 111B, the precipitated rust preventive material is filtered and removed together with insoluble corrosion products, and is led to the solid Y6 vehicle treatment equipment 37.

FIG. 3 shows a specific embodiment of the invention, and similarly to FIG. 2, it simultaneously shows the first invention to the third invention.

The suppression pool water 3a contains the following substances. In other words, the main radioactive substances are C〇-60 and Mn-54, which are mainly radioactive substances of structural materials.
and fission products Cs-134 and Cs-137. Insoluble corrosion products mainly include iron and zinc hydroxides and oxides, and rust preventives include chromate, hydrazine,
Contains hydroxybenzotriazole, etc.

Next, the structure and operation of this embodiment will be explained at the same time.

Suppression pool water 3 in suppression pool 3
a is sucked from the suppression pool water suction device 4 by the suction force of the transfer pump 6, and flows into the hollow filter mechanism 8 through the transfer pipe 58 and the hollow filter inlet pipe 7.

This hollow system filter mechanism 8 is used to suppress the suppression pool water 3.
It functions as a first stage mechanism to separate and remove impurities from a. That is, among the insoluble corrosion products contained in the suppression pool water 3a, those with a particle size of 0.1μ or more are removed by the hollow filter mechanism 8, and colloidal insoluble corrosion products with small particle sizes and Water-soluble radioactive materials (such as Cs-137) and rust preventive materials flow through the hollow filter mechanism 8, pass through the hollow filter outlet pipe 10, and flow into the receiving tank 11, where they are stored.

The liquid stored in this receiving tank 11 is transferred to the high pressure pump 13
The transport force causes the water to flow into the reverse osmosis membrane mechanism 15 through the reverse osmosis membrane transfer pipes 12 and 14.

This reverse osmosis membrane machine @15 performs the second stage separation and removal function. That is, colloidal insoluble corrosion products and rust preventive material contained in the three liquids in the receiving tank 11 are removed. Then, the water-soluble ions containing the water-based radioactive substance Cs-137 and the solution containing the organic rust preventive material that are not removed by the reverse osmosis membrane mechanism 15 flow out through the reverse osmosis membrane outlet pipe 16 and into the receiving tank 17. stored.

The solution containing bathing ions and the like stored in the receiving tank 17 is caused to flow into the desalting tower #421 through the desalting tower transfer pipes 18 and 20 by the transporting force of the pump 19.

This demineralization tower mechanism 21 performs a third stage separation and removal function. That is, while flowing through the desalination tower machine #421, the bath liquid comes into contact with the desalination agent, and the water bath ions and organic rust preventive material are separated and removed, resulting in clean water.

This clean water flows into the surge tank through the demineralization tower outlet pipe n, is stored, and is provided for reuse.

Note that this desalination tower mechanism 21 is preferably of a disposable type, since there is a possibility that the amount of the regenerating agent will increase if the desalting tower mechanism 21 is regenerated using the regenerating agent.

On the other hand, the colloidal insoluble corrosion products and rust preventive material separated and removed in the reverse osmosis membrane mechanism 15 are recovered in the receiving tank 11 through the recovery tank.

When this recovery is completed, the colloidal insoluble corrosion products and rust preventive material are crystallized by the transporting force of the pressure pump station.
vI transporters 6 and 27 lead to the crystallizer which forms the crystallization coprecipitation mechanism.

Into this crystallization tank (capital) are a large number of precipitant tanks 29, 2.
Each apple precipitant is injected through the precipitant injection pipe from 9 to precipitate the colloidal insoluble corrosion products and rust preventive material. The order of addition of the precipitant may be appropriately selected depending on the properties of the solution in the crystallization tank 30. For example, when containing chromate as a rust preventive material, add nickel salt, then add Huecocyanide potassium salt, Cs-1
34, Mn-54 is precipitated as a berlinate precipitate, then a ferric salt is added followed by alkali to precipitate Co-60, Mn-54 as a hydroxide precipitate.

This precipitate is discharged by appropriate means, but in this embodiment, a transfer pump 32, a precipitate transfer pipe 31,
The sediment is transferred to the hollow filter mechanism 8 by a sediment transfer mechanism consisting of 33.

In this way, the hollow filter 41! H) While the solution containing precipitates such as crystallized substances transferred to 18 flows through the hollow filter mechanism 8, the precipitates are removed therefrom. The liquid that has passed through the hollow filter mechanism 88 is then subjected to the above-described treatment again.

The insoluble corrosion products and precipitates separated and removed in the hollow filter mechanism 8 are removed by pumping air from the opposite direction to the filter from the backwashing air supply pipe 9 provided in the hollow filter mechanism 81. As a result, it is forcibly peeled off from the filter, and is compressed at the bottom of the tank of the hollow filter mechanism 8 to form a slurry. This concentrated slurry is sent to a waste treatment facility 37 through a concentrated waste liquid transfer pipe 36 by a slurry pump A, and is solidified.

In this way, in this embodiment, the hollow filter mechanism 8
This makes it possible to efficiently remove insoluble corrosion products with a particle size of 0.1μ or more.
It is possible to sufficiently reduce the radioactive load on the In addition, if there are many insoluble corrosion products in the reverse osmosis membrane mechanism 15, problems such as a decrease in the amount of permeated water and an increase in the frequency of backwashing may occur, but this embodiment prevents such problems. .

In addition, since insoluble corrosion products and precipitates can be concentrated using a medium nitrogen thread filter machine S8, these materials can be
There is no need to provide concentration equipment such as a sedimentation separation finger that shrinks, and since the demineralization tower mechanism 21 is disposable, there is no need to provide regeneration equipment for the demineralization tower mechanism, and the overall structure of the device is simplified and operability is improved. is also excellent. Furthermore, since the radioactivity of the suppression pool water 3a can be reduced, the radiation exposure of workers when repairing the suppression pool 3, etc. can be reduced. In addition, it is economical because the suppression pool water 3a can be reused, and if the processing capacity of the middle-nit thread filter mechanism 8 is approximately 10 to 20 times that of a normal filter, the amount of secondary waste generated will be reduced. will also decrease.

Note that water may be used instead of air for backwashing the hollow filter machine +1 #8, and the reverse osmosis membrane mechanism 15 and the desalination tower mechanism 21 may be formed in multiple stages as necessary. Good too.

〔Effect of the invention〕

Since the suppression pool water treatment device of the present invention is constructed and operates in this way, it can reliably remove all impurities from the suppression pool water and provide it for reuse, and it has a large processing capacity and is easy to operate. It has effects such as being stable.

[Brief explanation of drawings]

FIG. 1 is a longitudinal side view showing an example of a suppression pool, FIG. 2 is a block diagram showing an outline of the suppression pool water treatment apparatus of the present invention, and FIG. 3 is a configuration diagram showing a specific embodiment. 3... Suppression pool, 3a... Suppression pool water, B, 8... Hollow system filter mechanism, C2
15... Reverse osmosis membrane mechanism, D, 21. Desalination tower mechanism, F,
(28゜29,30)--crystallization coprecipitation mechanism, G (
31, 32, 33) - Sediment transfer mechanism. Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] 1. A hollow filter mechanism that removes insoluble corrosion products from the suppression pool water, and a reverse osmosis membrane that removes rust preventive materials from the fluid that flows out of the hollow filter mechanism! and a desalination tower mechanism that removes ionic substances from the fluid flowing out of the reverse osmosis membrane mechanism to produce clean water. 2. A hollow filter mechanism that removes insoluble corrosion products from the suppression pool water, a reverse osmosis membrane mechanism that removes rust preventive material from the fluid that flows out of the hollow filter mechanism, and this reverse osmosis membrane mechanism. A suppression pool water comprising a demineralization tower mechanism that removes ionic substances from the fluid flowing out to produce clean water, and a crystallization coprecipitation mechanism that precipitates the rust preventive material removed by the reverse osmosis membrane mechanism. processing equipment. 3. A hollow filter mechanism that removes insoluble corrosion products from the suppression pool water, a reverse osmosis membrane mechanism that removes rust preventive material from the fluid that flows out of the hollow filter mechanism, and this reverse osmosis membrane mechanism. a desalination tower mechanism that removes ionic substances from the fluid that flows out to produce clean water; a crystallization co-precipitation mechanism that precipitates the rust preventive material removed by the reverse osmosis membrane mechanism; A suppression pool water treatment device comprising a sediment transfer mechanism that transfers and removes the sediment precipitated by the sedimentation mechanism to the hollow filter mechanism and condenses the sediment together with the insoluble corrosion products.