JPS58102200A - Sedimentation seperating tank - 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] The present invention relates to a sedimentation tank.

Generally, in facilities that handle radioactive materials such as nuclear power plants, settling tanks are used to treat radioactive waste.

This sedimentation separation tank contains sludge (crud slurry, waste ion exchange resin, etc.) containing radioactive substances.

) is stored in a container for a long period of time in an attempt to attenuate the radioactive material's destructive potential.

That is, regardless of whether it is a continuous type or a batch type, this sedimentation separation tank is generally formed in the lower part of the container 1 as shown in FIG.
A storage section 2 that stores a sedative substance, a clarification section 3 that is formed in the upper part of the container 1 and that stores clarified water called decant water, and a clarification section 3 that is formed between the clarification section 3 and the storage section 2. It consists of a buffer zone 4.

In the sedimentation separation tank constructed in this manner, as shown in Fig. 2, when the object to be sedimented and separated is a substance that is relatively difficult to settle, such as general sludge, the buffer zone 4 is
By pouring these substances into the supply pipe 5 which opens into the supply pipe 5, they settle almost uniformly into the reservoir 2 of the container 1.

However, if the target to be sedimented and separated is a substance with an extremely fast sedimentation rate, such as waste ion exchange resin,
As shown in FIG. 3, the substance supplied from the supply pipe 5 to the buffer zone 4 has a so-called angle of repose JF! Storage part 2
will be deposited on the surface.

In this case, a space 6 is formed in the storage section 2 of the container 1 in which the waste ion exchange resin is not stored, which is undesirable from the standpoint of effective use of the sedimentation tank.

For example, as shown in FIG.
, 7d are inserted supply pipes 8a, 8b, Qc,
8d is opened, and the waste liquid supplied to the sedimentation separation tank by the pump 9 is caused to sequentially flow into the container 1 from all sides by opening and closing the on-off valves 7a17b, 7c, and 7d.

That is, for example, when the on-off valve 7a in the figure is open, the on-off valves 7b17c and 7d are closed, and the on-off valve 7a is closed.
When the fluid supply from the supply pipe 8a inserted reaches a certain value, the on-off valve 7a is closed, the on-off valve 7b is opened, and the waste liquid is supplied into the container 1 from the supply pipe 8b.

However, when using such a method, it is necessary to arrange a plurality of nozzles in the container 1, and a large number of supply pipes 8a, 8b, 8c, 8d are also required outside the container 1, and the on-off valves 7a, Switching work between 7b, 7c, and 7d is required.

As a result, the manufacturing cost of the settling tank increases and the operation becomes complicated.

Furthermore, the number of supply pipes 8a, 8b, 8c, and 8d increases, and it is necessary to arrange nozzles around the container 1, which causes various problems in the arrangement of the settling tank.

In order to solve such problems, conventionally, Figs.
Various methods have been taken as shown in the figure.

That is, FIG. 5 shows an example in which the stirrer 10 is inserted into the buffer zone 4. When such a method is used, the radioactive waste is stirred in the buffer zone 4 and then uniformly distributed in the container 1, but manufacturing costs and operating costs increase. Furthermore, stirring causes separation of the radioactive substance from, for example, a waste ion exchange resin, which reduces the sedimentation property of the radioactive substance, improves the treatment FRWR, and causes deterioration of the quality of the decanted water.

FIG. 6 shows an example in which the nozzle 11 formed at the tip of the supply pipe 5 is oscillated within the buffer zone 4.

When such a method is used, the radioactive waste is stored uniformly in the container 1 to some extent, but there is a drawback that the swinging device lacks reliability.

Figure 7 shows a spout arrangement that spews out water or air at the bottom of the container 1! ! 12 is shown.

In such a case, the radioactive waste will be agitated by water or air spouted from the spouting pipe 12 and stored almost uniformly in the container 1, but if air is used, this A filter system is required to collect and treat air, and when water is used, there is a problem in that the time required for waste liquid treatment increases by the amount of water used. In addition, since the entire radioactive waste is fluidized and stirred, the sedimentation density of the radioactive waste becomes smaller, and the effective storage capacity of the container 1 decreases, and due to stirring, components that are difficult to sediment gather in the upper part of the container 1, reducing the sedimentation performance. There is a drawback.

FIG. 8 shows an example in which the inlet of the supply pipe 5 is located at the clarifying section 3 and radioactive waste is stored in the buffer zone 4. In this case, it is possible to store approximately the same amount of radioactive waste as in the case of storing radioactive waste in the storage section 2, but there is a problem that the quality of the decant water deteriorates.

The present invention has been made in response to such conventional circumstances, and includes a container for separating sludge from h0 radioactive waste by sedimentation and storing the sludge up to a predetermined sludge storage position, and a container for storing the sludge in a predetermined sludge storage position. An object of the present invention is to provide a sedimentation separation tank characterized by comprising a plurality of nozzles that open to a storage position, and a branch pipe that connects these nozzles to a supply pipe that transfers the radioactive waste to the container. It is.

The details of the present invention will be described below with reference to the drawings.

In Figures 9 and 10, the code 13 is, for example, straight (¥6m
, a container with a depth of 8- is shown, and in the buff 1 zone 4 of the container 13, there is a cross-shaped pipe 14 as shown in FIG.
Among the branch pipes 14a, 14b, 14c, and 14d having the same pipe diameter constituting the cross-shaped pipe 14, the end of the branch pipe 14a is connected to the supply pipe 1 that penetrates the container 13.
5. Nozzles) 116a, 16b, 16c, 16d are provided at the tip of the cross-shaped pipe 14, respectively.
is formed. Further, a discharge pipe 17 for discharging water from decan is connected to the clarification section 3 of the container 13, and the iJ4
A discharge pipe 18 is provided above the W1 section 3 for discharging overflowing decant water.

In the settling tank configured as below, the supply pipe 15
The radioactive waste that has flowed in mainly flows out from the nozzle with the lowest resistance, for example 16a, and is deposited in the downstream storage section 2 in a chevron shape, and the top of this chevron-shaped section is connected to the nozzle 1.
6a, the fluid resistance acting on the nozzle 16a increases, and the flow of radioactive waste from the nozzle 16a is automatically stopped. Then, the remaining three nozzles 1
6b, the nozzle with the lowest resistance among 16C116d,
For example, radioactive waste begins to flow from 16b. In this way, the nozzles 16a, 16b, 16c with low resistance
, 16d, and finally the radioactive waste is deposited in the storage section 2 as shown in FIGS. 9 and 10.
is stored on average.

FIG. 11 shows another embodiment of the present invention, in which the pipe 19 is arranged in the container 13 in an H-shape. That is, a supply pipe 23 is arranged that branches from the middle part of a branch pipe 22 that connects two branch pipes 20 and 21 arranged in parallel and penetrates the container 13.
o, 21 have nozzles 24, 25, 26, .
27 is formed.

The pipe diameters of these branch pipes 20, 21, and 22 are the same.

In addition, since the structure other than the above is similar to that of the embodiment shown in FIGS. 9 and 10, the same reference numerals are given to the same members and the explanation thereof will be omitted.

In the sedimentation separation tank configured as above, the radioactive waste that flows in from the supply pipe 23 passes through the branch pipes 22, 20, 21, and flows out almost equally into the container 13 from the respective nozzles 24, 25, 26, 27. Then, it is deposited in a chevron shape in the storage section 2 below. However, in reality, there are differences in the flow of radioactive waste flowing out from each nozzle 24.2.25.26.27, so for example, the flow rate (X
The top of the chevron-shaped part formed below the nozzle 24 first contacts the nozzle 24, and
f) The fluid resistance increases and the nozzle 2 J h
The outflow of X et al.'s radioactive waste will be automatically stopped.

In this way, the top of the chevron-shaped portion formed below the nozzle 24.2 contacts the nozzle 24.2.
The outflow of radioactive waste is stopped sequentially from 5.26.27, and finally, the radioactive waste is stored in the storage section 2 at an approximately average rate.

As described above, in the sedimentation separation tank of the present invention, the flow resistance characteristics of the radioactive waste itself are used to distribute the radioactive waste to the branch pipes, and no on-off valve or other control mechanism is used. This allows the sedimentation tank to be very inexpensive and highly reliable. In addition, the utilization efficiency of the sedimentation separation tank can be sufficiently increased, and in particular, since the sedimentation time can be lengthened, compaction can be promoted and the sediment concentration can be increased. Moreover, since the radioactive waste can be completely contained within the buffer zone, there is no risk that the quality of the decanted water will deteriorate. Further, by discharging the radioactive waste in the container, the stagnant radioactive waste in the nozzle starts flowing again, so there is no risk of the nozzle being blocked.

In the embodiments described above, only one pipe penetrates the container, so production costs can be reduced, and restrictions on the layout are reduced, making it easy to route the pipes.

Furthermore, in the embodiments described above, since the diameters of the cross-shaped pipes are made into large-diameter pipes having the same diameter, the possibility of the pipes being blocked is reduced.

In the embodiments described above, if the same piping as that for supplying radioactive waste is used to carry out nodding with water, the chevron-shaped portion can be flattened and the storage efficiency can be further increased.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram to explain the sedimentation separation tank, Figure 2 is an explanatory diagram to reduce the settling state of radioactive waste that is relatively difficult to settle, and Figure 3 is a diagram showing the settling state of radioactive waste that has a high settling rate. Figure 4 is an explanatory diagram showing an example of a conventional sedimentation tank, and Figures 5 to 8 show a method for solving the problems of the sedimentation tank shown in Figure 4. Explanatory diagram, Figure 9 and 1st
0 is a vertical sectional view and a top view showing one embodiment of the present invention, and FIG. 11 is a top view showing another embodiment of the invention. 2......Storage section 1...
・・・・・・・・・Buffer Zone 13・・・・・・
...... Containers 14a, 14b, 14s
, 14d -- Branch pipe 15.23 --- Supply piping 16a , 16b , 16C, 16 (1. / Sl 20.
21.22...Branch pipe 24.25.26.27...Nozzle agent Patent attorney Sa Suyama - Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 #+0 Figure 11 Figure 3

Claims (1)

[Scope of Claims] (1) A container that sediments and separates sludge from radioactive waste and stores the sludge up to a predetermined sludge storage position, and a plurality of nozzles that open above the sludge storage position of this container. and a branch pipe connecting these nozzles and a supply pipe for transferring the radioactive waste into the container.
(2) The sedimentation separation tank according to claim 1, wherein the nozzle opens at the sludge storage position. (3) The nozzle opens within the boundary between the buffer zone and the storage section. (4) The radioactive waste is a used ion exchange resin. C.
The sedimentation separation tank according to any one of claims 1 to 3, characterized in that: