KR101961838B1 - A dust leak prevention system of nuclear fuel pellet production line - Google Patents

Abstract

The present invention relates to a dust leak prevention system for a nuclear fuel pellet production line, capable of preventing an accident of a worker caused by radiation exposure. According to the present invention, a conveying air line includes a fluid flow control means for allowing fluid to flow in one direction from the outside to the conveying air line. The fluid flow control means is a check valve and the conveying air line comprises a pipe connected to a dust collection apparatus. A protruding pipe protruding to one side is formed in the pipe and the fluid flow control means is detachably coupled to the protruding pipe through a coupling means.

Description

[0001] The present invention relates to a dust leakage prevention system for a nuclear fuel pellet production line,

The present invention relates to a system for preventing dust leakage in a nuclear fuel sintered product production line, and more particularly, to a dust leakage prevention system for a nuclear fuel sintered product production line that maintains a balance of pressure inside and outside of a dust collecting line and prevents leakage of radioactive dust from a dust collecting line .

A nuclear reactor is a device for artificially controlling the fission reaction of a fissile material and using thermal energy generated from fission as a power source.

Generally, in light water reactors, enriched uranium is used, which increases the ratio of uranium-235 to 2 to 5%. In order to process the nuclear fuel used in nuclear reactors, the uranium is processed into a cylindrical fuel sintered body (pellet) .

The sintered body thus formed is dried in a drying furnace, and then charged into a tube-shaped cladding tube made of a special alloy having good corrosion resistance, and then sealed to produce a nuclear fuel rod. The manufactured nuclear fuel rod is composed of a bundle of nuclear fuel assemblies After being loaded into the reactor core, combustion takes place through nuclear reaction.

The sintered body is manufactured in a cylindrical shape having a diameter of about 8 or more and a length of about 10, although there is a difference depending on the type of fuel. Therefore, about 400 sintered bodies are charged in a fuel rod having a length of about 4 m.

The (U, Gd) O 2 sintered body is usually pulverized together with UO 2 powder and Gd 2 O 3 powder, and the sintered body is formed from the pulverized powder by molding and sintering in the same manner as the production of the UO 2 sintered body.

Hereinafter, a method of manufacturing a (U, Gd) O 2 fuel sintered body will be briefly described.

First, UO2 powder is mixed with Gd2O3 powder or Er2O3 powder and pulverized to prepare UO2-Gd2O3 powder or UO2-Er2O3 powder.

At this time, the content of Gd2O3 is about 15% by weight or less and the content of Er2O3 is 4% by weight or less.

The pulverized powder is compression molded to produce a compact. The compact can be sintered by heating in a reducing gas atmosphere and holding the compact at a temperature of 1600 ° C to 1800 ° C for 2 to 4 hours.

On the other hand, dusts are inevitably generated in operation of each equipment for the sintered body manufacturing process, and each equipment has a dust collecting line for collecting the dust.

1, a dust collector 10 having a negative pressure of about -200 mbar is installed in a factory, and is connected to the dust collecting apparatus 10 and each apparatus 20, Is a conveying air line (30).

A powder container 20a for accommodating dust generated in a sintering process is installed in each equipment 20 for the sintered product manufacturing process and the powder container 20a includes a powder container 20a, Is connected to the dust collecting apparatus (10) through a baling air line (30).

Meanwhile, in the powder preparation line of the sintered product production line, the dust generated from each equipment 20 is collected through the negative pressure of the dust collecting apparatus 10, and due to the excessive negative pressure of the dust collecting apparatus 10 There is a problem that the powder container 20a is shrunk or damaged.

In order to solve this problem, a part of the conveying air line 30 is exposed to the outside to balance the internal and external pressures of the conveying air line 30, thereby preventing damage to the powder container 20a.

However, when the dust is continuously accumulated on a part of the conveying air line 30 exposed to the outside as described above, or if the inside of the conveying air line 30 is blocked somewhere, Due to the static pressure, dust of the conveying air line 30 could leak and scatter to the outside through the exposed portion of the conveying air line 30.

Since the dust is irradiated, the dust scattered to the outside leads to radiation exposure of the worker, which poses a problem that the safety of the worker is threatened.

1, the powder preparation line of the sintered product production line is provided with a blending equipment 21, a mill equipment 22 and a granulation equipment 23, A static pressure is generated in the course of rotation of the hammer mill when the compressor 22 is operated, and dust generated during the manufacture of the sintered body through the exposed portion of the conveying air line 30 can be leaked.

Korea Registration No. 10-0922565

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a check valve in a conveying air line so that outside air can be always supplied only inside a conveying air line, Dust leakage in the production line of nuclear fuel sintered body which prevents worker safety accidents by radiation exposure by preventing damage of manufacturing equipment by preventing excessive negative pressure of dust collecting device and preventing dust leakage from conveying air line Prevention system.

In order to accomplish the above object, the present invention provides a method of manufacturing a nuclear fuel sintered body, which comprises manufacturing equipment for producing a nuclear fuel sintered body, dust collecting apparatus for generating negative pressure for sucking dust generated from each manufacturing equipment, And a conveying line for supplying dust generated from the manufacturing equipment to the dust collecting device, wherein the conveying air line is supplied with a fluid flow only from the outside in one direction of the conveying air line Wherein the fluid flow control means is a check valve, the conveying air line is constituted by a pipe connected to a dust collecting device, a protruding pipe protruding toward one side is formed in the pipe body , Said fluid flow control means being detachably coupled to said projecting tube via fastening means And the check valve is configured to open and close the pipe by the expansion and contraction of the spring to expand and contract the spool so that the outside air flows through the check valve in an environment where negative pressure is generated in the conveying air line, So that damage due to shrinkage of the manufacturing equipment can be prevented and dust in the conveying air line can be prevented from leaking through the check valve The present invention provides a system for preventing dust leakage in a production line of a nuclear fuel sintered body.

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The dust leakage prevention system of the fuel sintering production line according to the present invention has the following effects.

First, the pressure balance inside and outside the conveying air line can be maintained by installing a check valve on the conveying air line for collecting dust generated from each equipment in the nuclear fuel sinter production line.

Accordingly, since excessive negative pressure is prevented from being generated in the manufacturing equipment for producing the nuclear fuel sintered body, the manufacturing equipment can be prevented from damage due to shrinkage or the like.

 Second, even when dust builds up on the conveying air line and a static pressure is generated in the conveying air line, due to the nature of the check valve, the dust of the conveying air line is prevented from leaking to the outside, It is possible to prevent the safety accident of the vehicle.

1 is a drawing showing a powder preparation equipment line for producing a nuclear fuel sintered body
2 is a schematic view showing a dust leakage prevention system of a fuel sintered product production line according to a preferred embodiment of the present invention;
3 is a photograph showing the flow of the fluid in the dust leakage prevention system of the fuel sintered product production line according to the preferred embodiment of the present invention
4 is a view showing a check valve of a dust leakage prevention system of a fuel sintered product production line according to a preferred embodiment of the present invention
5 is a cross-sectional view showing a check valve of a dust leakage prevention system of a fuel sintered product production line according to a preferred embodiment of the present invention
6 is a photograph showing another example of a check valve of the dust leakage prevention system of the fuel sintered product production line according to the preferred embodiment of the present invention
7 is a sectional view showing another example of a check valve in a dust leakage prevention system of a fuel sintered product production line according to a preferred embodiment of the present invention.

It is to be understood that the words or words used in the present specification and claims are not to be construed in a conventional or dictionary sense and that the inventor can properly define the concept of a term in order to describe its invention in the best possible way And should be construed in light of the meanings and concepts consistent with the technical idea of the present invention.

Hereinafter, a dust leakage prevention system (hereinafter referred to as a dust leakage prevention system) of a fuel sintered product production line according to a preferred embodiment of the present invention will be described with reference to FIGS. 2 to 7 attached hereto.

The dust leakage prevention system is used in a production line of a nuclear fuel sintering body, in which dust generated from each equipment during the preparation of a powder for producing a nuclear fuel sintered body, Prevent leakage.

In other words, the dust leakage prevention system prevents the damage of each equipment by negative pressure by maintaining the pressure balance inside and outside of the conveying air line during the dust collecting process. In addition, even if the static pressure in the conveying air line is generated through the crushing equipment, It is possible to prevent dust from leaking from the flying air line.

To this end, the conveying air line is provided with the fluid flow control means 100 as shown in FIG.

The fluid flow control means 100 forms a flow path for introducing outside air into the conveying air line 30 and is provided such that fluid flows only from the outside to the inside of the conveying air line 30. [

That is, outside air is introduced into the conveying air line 30 through the fluid flow control means 100 so that the fluid does not flow back from the conveying air line 30 to the outside of the conveying air line 30 Thereby preventing the dust from leaking to the outside.

The fluid flow control means (100) is preferably provided as a check valve.

3, a plurality of check valves 100 are installed in the conveying air line 30, and the flow of the fluid is limited to the inside of the conveying air line 30 outside the conveying air line 30 Can be understood.

This is due to the negative pressure generated from the dust collecting apparatus 10 as described above.

The check valve 100 will be described with reference to FIGS. 4 and 5. FIG.

The check valve 100 is installed in the conveying air line 30 through the fastening means 200 and the convection tube 31 for installing the check valve 100 is formed in the conveying air line 30 .

The protruding pipe 31 is protruded from the conveying air line 30 constituted by a pipe body, and a thread is preferably formed on the outer circumferential surface thereof.

And, the check valve 100 controls the fluid flow in only one direction, and can be provided as a known check valve.

The check valve 100 is known in various types and is not limited to any particular type in the present invention.

Although not shown, the opening / closing means for opening / closing the pipeline of the check valve 100 in one direction is not shown, but it is preferable that the opening / closing means is of a ball type.

That is, a spring (not shown) is expanded and contracted by a fluid pressure to open a pipe (not shown), and the expansion and contraction force of the spring can be designed in consideration of the outside air pressure.

The fastening means 200 fastens the check valve 100 to the projecting pipe 31 of the conveying air line 30 and the nipple 210 and the clamp flange 220, A clamp 240, a clamp body 250, and a clamp ring 260. The clamp nut 260 includes a clamp nut 260,

The nipple 210 is connected to the end of the check valve 100 and is connected to the conveying air line 30. The nipple 210 has a hollow shape penetrating both sides thereof.

A male screw is formed on the outer peripheral surface of the nipple 210, and a female screw is formed on the inner peripheral surface of the one end of the check valve 100.

The clamp flange 220 is a hollow flange that is coupled to the protruding tube 31 and serves as an intermediate means for connecting the protruding tube 31 to the check valve 100. [ .

 The clamp nut 230 is interposed between the projecting pipe 31 and the clamp flange 220 and is an intermediate means for connecting the clamp flange 220 to the projecting pipe 31.

To this end, a male screw is formed on the outer circumferential surface of the projecting tube 31, and a female screw is formed on the inner circumferential surface of the clamp nut 230.

Accordingly, the protruding pipe 31 is screwed to one end of the clamp nut 230, and the clamp flange 220 is screwed to the other end of the clamp nut 230.

At this time, the inner circumferential surface of the one end of the clamp nut 230 and the inner circumferential surface of the other end are formed to have different diameters to form a step.

Thus, a step is formed on the inner circumferential surface of the clamp nut 230, and the spacer 240 is positioned at the end of the clamp nut 230.

The spacer 240 is formed in a ring shape having both sides penetrated, and an O-ring is disposed on the inner peripheral surface thereof.

The clamp body 250 serves to fasten the nipple 210 coupled with the check valve 100 and the clamp flange 220 coupled to the protrusion pipe 31 and is configured in the form of a hinge- do.

The other end of the clamp body 250 is coupled to the check valve 100 and the protruding pipe 220 by being fastened to the other end of the clamp body 250 by a butterfly bolt, (31).

A clamp ring 260 is further provided between the nipple 210 and the clamp flange 220 to maintain airtightness.

The check valve 100 is installed in the conveying air line 30 and the outside air is introduced into the conveying air line 30 through the check valve 100 only in one direction.

Accordingly, in the environment where negative pressure is generated in the conveying air line 30 by the dust collector 10, as the outside air is introduced through the check valve 100, the conveying air line 30, It is possible to prevent damage due to shrinkage of the manufacturing equipment 20 due to an excessive negative pressure being not generated in the sintered product manufacturing equipment 20 and the dust inside the conveying air line 30 can be prevented from being damaged by the check valve It is possible to prevent a worker's safety accident due to radiation exposure because the worker does not leak through the worker 100.

On the other hand, in the case where the check valve 100 is installed in the conveying air line 30, the conveying air line 30 (not shown) is connected through the flange 270 for welding rather than the projecting tube 31 coupling through the clamp nut 230 ).

This can be understood from FIG. 6 and FIG.

As can be seen, the clamp flange 220 is fixed to the welding flange 270 by welding, and the clamp flange 220 is connected to the check valve 100 through the above-described series of processes.

In the state where the check valve 100 is provided, a welding flange 270 is installed in a specific section of the conveying air line 30, and then the welding flange 270 is fastened to the conveying air line 30 The check valve 100 is engaged.

As described above, in the dust leakage prevention system of the fuel sintered product production line according to the present invention, the check valve 100 is installed in the conveying air line 30 so that the pressure balance inside and outside the conveying air line 30 can be maintained Dust leakage from the conveying air line 30 can be prevented, and a worker safety accident due to radiation exposure can be prevented in advance.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art.

10: Dust collector 20: Manufacturing equipment
20a: Powder container 21: mixing equipment
22: Crushing equipment 23:
30: Conveying air line 31: Projection tube
100: fluid flow control means (check valve) 200: fastening means
210: Nipple 220: Clamp flange
230: clamp nut 231: step
240: spacer 250: clamp body
260: Clamp ring 270: Flange for welding

Claims (3)

A dust collecting device for generating negative pressure for sucking dust generated from each manufacturing equipment, and a dust collecting device connected between each manufacturing equipment and the dust collecting device for collecting dust generated from the manufacturing equipment to the dust collecting device 1. A production line of a nuclear fuel sintering body including a conveying air line for providing a conduit to be conveyed,
Wherein the conveying air line is provided with a fluid flow control means for externally flowing fluid only in one direction of the conveying air line,
Wherein the fluid flow control means is a check valve,
The conveying air line is constituted by a pipe connected to a dust collecting device,
A protruding tube protruding toward one side is formed in the tubular body, the fluid flow control means is detachably coupled to the protruding tube through a fastening means,
The check valve is configured to open and close the pipe by the ball by expansion and contraction of the spring,
In the environment where negative pressure is generated in the conveying air line, as the outside air is introduced through the check valve, the internal and external pressure balances of the conveying air line are maintained and excessive negative pressure is not generated in the sintering machine manufacturing equipment, And the dust in the conveying air line is prevented from leaking through the check valve. The dust leakage prevention system of the fuel sintered product production line is characterized in that the dust is prevented from leaking through the check valve.
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