JPH0439611B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a device for taking a liquid sample from a UF ₆ (uranium hexafluoride) cylinder, and in particular:
This invention relates to a UF ₆ liquid sampling device that is equipped with a measuring cylinder of a predetermined volume in the middle of a pipe connecting a cylinder and a sampler to collect a certain amount.

[Conventional technology]

Conventional techniques for collecting liquid UF ₆ (uranium hexafluoride) include, for example, dropping liquid UF ₆ from piping by gravity;
There is no method for extracting a fixed amount of UF ₆ .

[Problem to be solved by the invention]

An object of the present invention is to provide a UF ₆ liquid sampling device that can easily take out a fixed amount of sample while handling radioactive materials and various handling restrictions.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a cylinder having a sampled object UF ₆ inside, a nozzle attached to the cylinder and used to take in and out the contents of the cylinder, a sampler that stores the UF ₆ in the cylinder as a small sample, and In the UF ₆ liquid sampling device, which consists of a pipe connected to connect the nozzle and the sampler to collect the UF ₆ in the cylinder into the sampler, and a valve installed between the pipe and the sampler for operation, a specified amount of sample is transferred to the sampler. a metering cylinder provided in a part of the piping for sampling and whose total volume with the piping is smaller than the volume of the sampler; a first position where the inlet of the nozzle is above the level of the UF ₆ liquid in the cylinder; and an inlet of the nozzle. and a drive means for moving the cylinder between a second position where the cylinder is below the level of the UF ₆ liquid in the cylinder.

[Effect]

UF ₆ (uranium hexafluoride) handled by the device of the present invention
is a radioactive substance, and in order to extract UF ₆ as a liquid, it is important to do so at temperatures above normal temperature and pressure, and to extract a certain amount safely.

First, UF ₆ is in a solid state when handled at room temperature, but the density of a solid is about 5 g/cc, while the density of a liquid is about 3 to 4 g/cc.
In the case of liquids, the density decreases as the temperature increases. Due to this physical property, it is necessary to avoid overfilling the container containing the sample. For example, if the sample is filled with liquid and solidifies in the sampler, the density will decrease when the sampler is heated and liquefied. This is a dangerous situation. Furthermore, if the sampler is filled to the brim with liquid, the same situation will occur if the sampler is heated next time, or if the temperature becomes higher than that at the time of sampling, which is dangerous. For this reason, it is necessary to control and sample the amount of liquid in the sampler that is smaller than the volume of the sampler.

If you want to limit the amount of sample to be collected, for example, you can make a sampler in a transparent container and take it little by little visually, but the material being handled is radioactive, and it needs to be heated to make it into a liquid, and the pressure is high. Samplers are generally made of metal for safety reasons, and it is difficult to adjust the sample amount visually.

In view of the above-mentioned background, the present invention makes it possible to collect a quantitative sample at a temperature higher than normal temperature and a pressure higher than normal pressure, and under a condition that is invisible to the naked eye.

In addition, as a method for collecting liquid from a cylinder, there are also methods such as operating a compressor to suck out air and sucking up a fixed amount of liquid, or attaching a valve to the nozzle of the cylinder and collecting a fixed amount by opening and closing the valve. . However, in the former method, when the air is sucked out, the radioactive substance UF ₆ is vaporized and sucked out, which is a problem from a safety standpoint, and there is also the problem of loss of UF ₆ .
In the latter method, the sample is collected by opening and closing the valve, so the nozzle must be installed so that the inlet of the nozzle is always below the UF ₆ liquid level in the cylinder, and the liquid UF ₆ is always filled up to the nozzle and valve positions. If cracks occur at the nozzle and valve mounting points, liquid UF ₆ may leak from there, which is extremely dangerous. That is, from a safety point of view it is necessary that the inlet of the nozzle is normally located above the liquid UF ₆ .

The present invention makes it possible to safely remove a certain amount of liquid UF ₆ at or above normal temperature and pressure.

The operation of the apparatus of the present invention that achieves the above will be explained with reference to FIG. FIG. 1 shows an example in which a means for rotating the cylinder 2 is provided as a means for moving the cylinder 2. In other words, when filling a standard cylinder 2 with the specified amount, if the cylinder 2 is placed horizontally, UF ₆
The liquid level is generally only below the nozzle 6, so while the UF ₆ is heated and liquefied in the cylinder, rotate the cylinder 2 so that the inlet of the nozzle 6 is above the UF ₆ liquid level inside the cylinder 2. the first position and the nozzle 6
and a second position where the inlet of is below the UF ₆ liquid level in cylinder 2. Hereinafter, steps S1 (step 1) in FIG. 1 to S4 (step 4) in FIG. 1 will be explained in order.

[Step 1] A state in which UF ₆ 11 is liquefied by heating the cylinder 2 is shown. A pipe 7 having a measuring cylinder 8 is attached to the nozzle 6 of the cylinder, and a sampler 10 is attached via a remote control valve 9. The total volume of the piping 7 and the measuring cylinder 8 is smaller than that of the sampler 10. At this time,
The inlet of the nozzle 6 is above the liquid level of the UF ₆ 11 (first position).

[Step 2] By rotating the cylinder 2 with the remote control valve 9 closed in Step 1, the nozzle 6 is heated to UF ₆
11 is below the liquid level (second position), so the UF ₆ in the cylinder is important to the measuring cylinder 8 and piping 7.
Fill up to.

[Step 3] Next, return cylinder 2 to its original position (nozzle 6 is UF ₆ 1
The liquid UF ₆ is separated from the UF ₆ in the cylinder 2 while being retained in the pipe 7 and the metering cylinder 8.

[Step 4] Next, by opening the remote control valve 9, only the amount retained in the pipe 7 and the measuring cylinder 8 separated from the UF ₆ 11 in the cylinder falls into the sampler 10 by gravity. At this time, the nozzle 6 is inside the cylinder.
Since it is above the liquid level of UF ₆ 11 (first position), no liquid UF ₆ flows from the cylinder to the sampler.

As a result of the above, the sampler is not overfilled under normal temperature and pressure conditions that are impossible to see.
A sample of a fixed amount of liquid UF ₆ can be safely taken.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, the cylinder tank 1 is the cylinder tank 2.
a drive sorter 3 for rotating the drive sorter 3, a drive force transmission shaft 4 connected to the drive sorter 3, a mechanism 5 connected to the drive shaft 4 and transmitting the drive force to the cylinder 2, and a heat exchanger for heating the inside of the cylinder tank 1. It is equipped with a container 12. The cylinder 2 is housed in the cylinder tank 1 and has a nozzle 6 for taking out the liquid UF _6. A pipe 7 having a metering cylinder 8 is attached to the nozzle 6, and a sampler 10 is attached below the pipe 7. The total volume of the piping 7 and the measuring cylinder 8 is smaller than that of the sampler 10 as described above. In this state, the inside of the cylinder is heated by the heat exchanger 12.
The UF ₆ is heated and soaked, and the UF ₆ liquid is sampled in the sampler using the four steps described above. After sampling in the cylinder tank 1 in this manner, the cylinder tank 1 is cooled, the door of the cylinder tank 1 is opened, and the sampler 10 is separated from the measuring cylinder 8, thereby completing the sample collection.

According to this embodiment, the piping 7 and the measuring cylinder 8 are
A fixed amount of liquid UF ₆ , determined by the volume of the sampler, can be safely collected without overfilling the sampler.

In the above embodiment, a case has been described in which the pipe 7 is equipped with the measuring cylinder 8. However, if the volume of the pipe 7 is the same as the sampling volume of the sampler, the measuring cylinder 8 is unnecessary. In this case, the pipe 7 plays the role of a measuring cylinder, and therefore the term "measuring cylinder" is used in the claims including this case.

Furthermore, in the above embodiment, there is a first position where the inlet of the nozzle 6 is above the UF ₆ liquid level in the cylinder, and a second position where the inlet of the nozzle 6 is below the UF ₆ liquid level in the cylinder. Although a mechanism for rotating the cylinder 2 is used as a driving means for moving the cylinder 2 between The inlet of UF 6 is placed below the liquid level of UF ₆ in the cylinder, allowing liquid UF ₆ to fall from cylinder 2 into metering cylinder 8 by gravity.

〔Effect of the invention〕

According to the present invention, it is possible to safely collect a certain amount of liquid UF ₆ without overfilling the sampler under conditions that are above normal temperature and above normal pressure and cannot be visually observed.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the principle of sample collection according to the present invention, and FIG. 2 is a diagram illustrating the principle of sample collection according to the present invention _.
FIG. 2 is a schematic diagram of a liquid sampling device. Explanation of symbols: 1...Cylinder tank, 2...Cylinder, 3...Drive sort, 4...Drive shaft, 5...;
Driving force transmission mechanism, 6... Nozzle, 7... Piping, 8
...Measuring cylinder, 9...Remote control valve, 10...
Sampler, 11...UF ₆ , 12... Heat exchanger.

Claims (1)

[Scope of Claims] 1. A cylinder 2 having an object to be sampled UF ₆ therein, a nozzle 6 attached to the cylinder and used to take out and take out the contents of the cylinder, a sampler 10 for storing the UF ₆ in the cylinder as a small sample, and the cylinder. In the UF ₆ liquid sampling device, which consists of a pipe 7 connected to connect the nozzle 6 and the sampler 10 to collect the UF 6 in the sampler, and a valve 9 provided for operation between the pipe 7 and the sampler 10, a specified amount of UF ₆ is collected. A metering cylinder 8 is provided in a part of the piping 7 to collect a sample of the UF ₆ into the sampler, and the total volume with the piping 7 is smaller than the volume of the sampler; and drive means 3, 4, 5 for moving the cylinder between a first position where the nozzle 6 is located and a second position where the inlet of the nozzle 6 is below the UF ₆ liquid level in the cylinder 2. UF ₆ liquid sampling device.