JPH0220670Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a radioactive liquid collection and dilution device.

(Prior art) Collection and extraction of the primary coolant (light water, i.e., H ₂ O) currently used in light water reactor nuclear power plants
To explain the dilution device with reference to Fig. 1, 1 is a sample liquid cooler, 2 is a sample liquid pressure reducer, 3 is a sample liquid collection tube, 4 is a sink, 10 is a desorption section, and 11 is a sample liquid inlet pipe. 12 and 13 are outlet pipes for the sample liquid, 14 is the drain pipe of the sink 4, 15 and 16 are the refrigerant conduits of the cooler 1, and 21 to 29 are on-off valves, which allow the sample liquid (primary coolant = radioactive liquid) to flow. It is led from the inlet pipe 11 through the valve 21 to the cooler 1, where it is cooled to about room temperature, and then led to the pressure reducer 2, where the pressure is reduced. When the sample liquid that has been cooled to room temperature and pressure and is depressurized is sampled from the outlet pipe 13 via the valves 22, 27, and 29, the valves 23, 2
6 and 29 are closed, valves 22, 27, and 28 are opened, and the sample liquid, which has been cooled and depressurized to about room temperature and pressure in the pressure reducer 2, is passed for a while in the direction of the outlet pipe 12.
Next, the valve 29 is opened, and the sample liquid from the drain pipe 13 is received in the sink 4, and then flows through the drain pipe 14 to the processing equipment (not shown).After this process has been carried out for a while, the sample liquid is discharged from the outlet pipe 13. Collect liquid. In the above, a sample liquid is collected from the outlet pipe 13. The above is a case where a sample liquid is collected from the outlet pipe 13. However, when a sample liquid is collected from the sample liquid collection pipe 3, the valves 27, 29 are closed, the valves 22, 23,
24, 25, and 26 are opened, and the sample liquid that has been cooled and depressurized to room temperature and normal pressure in the pressure reducer 2 is sufficiently passed through the sample liquid collection tube 3, and then the valves 23, 2 are opened.
4, 25, and 26 were closed, and the sample liquid collection tube 3 was removed from the detachable parts 10, 10.

(Problem to be solved by the invention) In nuclear power plants, during normal operation, the radioactivity concentration per unit volume of the liquid to be collected, such as primary cooling water, is low, so the conventional collection and collection of radioactive liquid shown in Figure 1 above is not possible. Even if a dilution device is used, there is not much risk of exposure, but in the event of an accident (this accident is a design accident and rarely occurs in reality) and the radioactivity concentration is high, the sample liquid collection tube 3 should be removed and removed. Part 10,1
There was a problem in that there was a great risk of exposure to radiation when removing it from zero. Furthermore, in the event of an accident, the concentration of trapped substances (for example, boron in a pressurized water reactor) and nuclides in the liquid to be collected should increase considerably compared to during normal operation, so it is necessary to dilute the liquid to be collected. With the conventional radioactive liquid collection and dilution equipment shown in Figure 1, this work had to be carried out by the operator himself, and there was a risk of radiation exposure.

The present invention has been proposed in view of the above-mentioned problems, and its purpose is to promote mixing and dilution of a sample liquid and dilution pure water, thereby improving the accuracy of dilution. Sample liquid collection and dilution work can be performed safely and efficiently without the risk of exposure to radiation. Another object of the present invention is to provide a radioactive liquid collection and dilution device that can shorten the cleaning time of the diluter.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a sample liquid introduction pipe and a sample liquid measuring pipe whose inlet end is connected to the sample liquid introduction pipe via a first on-off valve. , a dilution pure water supply pipe connected to the inlet end of the sample liquid measuring tube via a second on-off valve and a dilution pure water meter, and a third on-off valve at the outlet end of the sample liquid measuring tube. In a radioactive liquid collection and dilution apparatus having a diluter that is connected at the bottom via a diluter and is installed in an upright position at a higher position than the sample liquid measuring tube, an inert gas is supplied to the inlet end of the sample liquid measuring tube. The pipes are selectively connected, and an exhaust pipe is connected to the diluter.

(Function) The radioactive liquid collection and dilution device of the present invention is configured as described above, and by opening and closing each on-off valve, pure water for dilution is metered from the pure water supply pipe for dilution. The water is supplied and sprayed into the diluter through the diluter, and this is washed.Then, the pure water for dilution is supplied from the pure water supply pipe for dilution, through the pure water meter for dilution, and into the sample liquid measuring tube. After cleaning, a certain amount of the sample liquid is confined in the sample liquid measuring tube, and the gas inside the diluter is exhausted from the diluter through the exhaust pipe.
Furthermore, while pushing out the cleaning water (pure water for cleaning) in the diluter with the pure water from the pure water supply pipe for dilution, the pure water for dilution is introduced into the diluter, and then the inert gas is diluted from the bottom of the diluter. The sample liquid and the dilution pure water are stirred by inert gas bubbles, and the sample liquid uniformly diluted with the dilution pure water is stored in the diluter. Send the sample liquid to an analyzer, etc. for analysis.

(Embodiment) Next, the radioactive liquid collection and dilution apparatus of the present invention will be explained using an embodiment shown in FIG. 2. 101 is a sample liquid cooler, 102 is a sample liquid pressure reducer,
104 is a sink, 105 is a sample liquid measuring tube, 10
6 is a diluter, 107 is a pure water measuring device for dilution, 108
is the pure water supply pipe for cleaning, and 108a is the diluter 10
The water nozzle installed in the upper part of 6, the same water nozzle 1
08a is connected to the cleaning pure water supply pipe 108. Note that this water nozzle 108a is connected to the valve 13.
Washing water supplied through 8,147 is diluted with diluter 1.
It is provided in order to uniformly spray the liquid toward the inner wall surface of the 06. In addition, 111 is a sample liquid introduction tube.
112 is a drain pipe, 114 is a pure water supply pipe for dilution,
115 and 116 are refrigerant conduits of the cooler 101;
117 is a nitrogen gas supply pipe, 118 is an exhaust pipe, 12
0 is the diluted sample liquid discharge pipe, 124 is the sink 1
04 drain pipe, 131, 132, 133, 13
4,135,136,137,138,139,
143, 144, 146, 147 are valves, 151 is a sample liquid pressure gauge provided downstream of the sample liquid cooler 101, and 152 is a sample liquid temperature also provided downstream of the sample liquid cooler 101. Total, 1
53 is a level meter for the diluter installed in the diluter 106, the inlet end of the sample liquid measuring tube 105 is connected to the sample liquid introducing tube 111 via the first on-off valve 133, and the inlet end of the sample liquid measuring tube 105 is connected to The inlet end is the second
It is connected to the dilution pure water supply pipe 114 via an on-off valve 134 and a dilution pure water meter 107, and the outlet end of the sample liquid measuring pipe 105 is connected to the bottom of the diluter 106 via a third on-off valve 135. The diluter 106 is installed in an upright position higher than the sample liquid measuring tube 105. In the radioactive liquid collection and dilution device of the present invention, the inert gas supply pipe 117
is selectively connected to the inlet end of the sample liquid metering tube 105 by a valve 138, and the exhaust tube 11 is connected to the diluter 106.
8 is provided.

Next, the operation of the radioactive liquid collection and dilution apparatus shown in FIG. 2 will be explained in detail. In this description, it is assumed that all valves unless otherwise specified are closed. () Valve 137, 138, 139, 147, 135, 13
6, 142, 144 are opened, pure water for dilution is supplied from the pure water supply pipe 114 into the diluter 106, and is sprayed onto the inner wall surface of the diluter 106 by the water spray nozzle 108a. Wash. At this time, if the valve 146 is opened and nitrogen gas (inert gas) is supplied at the same time, the cleaning effect can be increased. The cleaning water remaining in the diluter 106 is
Valve 146, 147, 135, 136, 142, 1
44 may be opened and extrusion may be performed using nitrogen gas. Next, the valves 134, 136, 142, and 144 are opened to wash the sample liquid measuring tube 105 with pure water for dilution. Note that in order to perform the above-mentioned cleaning reliably, this series of cleaning steps is repeated multiple times. ()
After opening the valves 131, 132, 133, 136, and 144 to allow the sample liquid to flow through this system for a certain period of time, each valve is closed to confine a certain amount of the sample liquid in the sample liquid measuring tube 105. () valve 137,
139, 134, 135, and 145 are opened to drain the gas in the diluter 106 from the exhaust pipe 110 to the diluter 1.
06 While exhausting the water to the outside and pushing out the cleaning water (pure water for cleaning) in the diluter 106 with the deionized water from the deionized water supply pipe 114, the deionized water for dilution is transferred to the diluter 10.
6. () When a predetermined amount of pure water for dilution is introduced into the diluter 106, valves 138, 134, 135, 146,
145 is opened, nitrogen gas is introduced into the diluter 106 from the bottom of the diluter 106, and the sample liquid and the pure water for dilution are stirred by the nitrogen bubbles. () Thus, the sample liquid uniformly diluted with the dilution pure water is stored in the diluter 106. () valve 137,
139, 134, 136, 142, and 144 are opened, and the sample liquid transfer system is washed with dilution pure water. () Valve 135, 136, 142, 143,
146 is opened, and the diluted sample liquid in the diluter 106 is sent to the analyzer or the diluted sample liquid container (see sample liquid collection tube 3 in FIG. 1) via the diluted sample liquid discharge pipe 120. () Once the analysis of the diluted sample liquid is completed, proceed as described in () above.
Clean the inside of the diluter 106 and the piping.

(Effect of the invention) As described above, the present invention
and a sample liquid measuring tube 105 whose inlet end communicates with the sample liquid introduction tube 111 via the first on-off valve 133.
, a dilution pure water supply pipe 114 connected to the inlet end of the sample liquid measuring tube 105 via a second on-off valve 134 and a diluting pure water meter 107 , and a third In a radioactive liquid collection/dilution apparatus having a diluter 106 connected to the bottom via an on-off valve 135 and installed in an upright position at a higher position than the sample liquid measuring tube 105, the inlet of the sample liquid measuring tube 105 An inert gas supply pipe 117 is selectively connected to the end of the diluter 10.
6 is connected to the exhaust pipe 118, and each on-off valve 13
By opening and closing 3,134,135,
Supplying pure water for dilution from the pure water supply pipe 114 to the diluter 106 via the pure water meter 107 for dilution,
This is sprayed and washed, and then the dilution pure water is supplied from the dilution pure water supply pipe 114 to the dilution pure water meter 10.
7 to the sample liquid measuring tube 105 to wash it, and then supply the sample liquid to the sample liquid measuring tube 105.
Then, while exhausting the gas in the diluter 106 to the outside of the diluter 106 from the exhaust pipe 118, the cleaning water (pure water for cleaning) in the diluter 106 is further discharged from the pure water supply pipe 114 for dilution. The pure water for dilution is introduced into the diluter 106 while being pushed out by the pure water of the sample liquid, and then the inert gas is introduced into the diluter 106 from the bottom of the diluter 106, so that the sample liquid and the pure water for dilution are mixed and diluted. can be promoted and the accuracy of dilution can be improved.

In addition, unlike the conventional radioactive liquid collection/dilution device, there is no need to remove the sample liquid collection tube 3 from the attachment/detachment parts 10, 10, and the sample liquid collection and dilution operations can be carried out safely and efficiently without the risk of exposure to radiation. can do well.

Also, the cleaning time of the diluter can be shortened. That is, the first point required when collecting a liquid sample after an accident is prompt and accurate collection and dilution. To do this, before or after collecting the sample liquid,
It is necessary to thoroughly clean the diluter with pure water for dilution, but the diameter of the piping to and from the diluter should be as large as possible to prevent liquid pooling and unnecessary exposure to radiation. Uses small piping,
It takes an extremely long time to send pure water into the diluter and discharge it from the diluter via this small-diameter piping. However, in the radioactive liquid collection and dilution device of the present invention, pure water is supplied to the dilution pure water supply pipe 11.
4 can be supplied to the diluter 106 via piping (cleaning pure water supply pipe 108) that bypasses the diluter 106, and there is no need to supply and drain pure water to the diluter through small-diameter piping. This has the effect of shortening the cleaning time.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a conventional radioactive liquid collection/dilution device, and FIG. 2 is a system diagram showing an embodiment of the radioactive liquid collection/dilution device according to the present invention. 105... Sample liquid measuring tube, 106... Diluter, 107... Pure water measuring device for dilution, 111... Sample liquid introduction tube, 114... Pure water supply pipe for diluting, 1
17...Inert gas supply pipe, 118...Exhaust pipe,
133...first on-off valve, 134...second on-off valve,
135...Third on-off valve.

Claims (1)

[Scope of utility model registration request] A sample liquid introducing tube, a sample liquid measuring tube whose inlet end is connected to the sample liquid introducing tube via a first on-off valve, and a second on-off valve and a measuring pure water for dilution at the inlet end of the sample liquid measuring tube. A third pipe is connected to the pure water supply pipe for dilution and the outlet end of the sample liquid measuring pipe.
In a radioactive liquid collection/dilution device having a diluter connected to the bottom via an on-off valve and installed in an upright position at a higher position than the sample liquid measuring tube, there is a diluter at the inlet end of the sample liquid measuring tube. 1. An apparatus for collecting and diluting radioactive liquid, characterized in that an active gas supply pipe is selectively connected and an exhaust pipe is connected to the diluter.