JPH0862391A - Activated carbon type rare gas hold up device - Google Patents

Abstract

PURPOSE: To improve the working environment by the improvement in filling work efficiency of activated carbon and the prevention of dust generation. CONSTITUTION: Activated carbon packages 21 are stached and filled in a body drum 13 having an upper mirror 14 and a lower mirror 15. To fill it with the packages, the manhole cover 20 of an upper manhole 19 and an exhaust gas outlet nozzle 16 are removed, the hanging ring 22 of the activated carbon package 21 is retained on a hanging hook to successively stack and fill with the activated carbon packages 21 in the body drum 13 through the upper manhole 19. In the activated carbon package 21, activated carbon is held in an activated carbon sheet, the upper surface of the activated carbon sheet is radially sewed by a reinforcing sewing thread, and the hanging ring 22 is mounted on the center part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radioactive waste waste treatment apparatus installed in a nuclear power plant or the like, and provides sufficient time decay of gaseous fission products (krypton, xenon, etc.) due to damage to fuel rods, etc. The present invention relates to an activated carbon type rare gas holdup device installed for the purpose of achieving the above.

[0002]

2. Description of the Related Art Radioactive gas waste generated in a nuclear power plant is a radioactive activated gas from a nuclear reactor and a gaseous fission product, which is hydrogen generated by radioactive decomposition of air and water flowing into a main condenser. And oxygen, gases activated in the furnace, fission product gas, etc. The radioactivity of these is sufficiently attenuated by a gas waste treatment device having an activated carbon adsorption tower and then diffused into the atmosphere.

A conventional gas waste treatment device will be described with reference to FIG. That is, as shown in FIG. 5, the radiant gas waste is extracted from the main condenser 1 by the steam type air extractor 2 and then heated by the exhaust gas preheater 3 to limit the radiant gas waste to the flammability limit. For the following reasons, hydrogen and oxygen in the radioactive gas waste are recombined by catalytic reaction in the exhaust gas recombiner 4 into steam.

Further, upstream of the exhaust gas recombiner 4, an exhaust gas preheater 3 for heating the radioactive gas waste to a superheated state is installed in order to maintain the reactivity of the catalyst. On the other hand, the steam used for extracting the radioactive gas waste and the steam generated by the recombination are returned to the main condenser 1 as condensate in the exhaust gas condenser 5.

Further, from the exhaust gas condenser 5 and thereafter, there is an activated carbon type rare gas hold-up (tower) device 9 for achieving sufficient time attenuation of the radioactive gas waste that has become the gas to be condensed, and the activated carbon There are an exhaust gas precooler 6, an exhaust gas dryer 7, etc. for maintaining hold-up performance.

The radioactive waste is reduced to a permissible limit or less by the equipment, the pre-filter 8 and the exhaust gas particle filter 10, and is discharged from the stack 12 to the atmosphere by the exhaust gas vacuum pump 11.

In this gas waste treatment device, the activated carbon type rare gas hold-up device 9 is, as shown in FIG. 6, a main body cylinder 13 and an upper mirror 14 connected to the upper and lower ends of the main body cylinder 13.
And the lower mirror 15, the exhaust gas inlet nozzle 16 for the radioactive gaseous waste containing the gaseous fission products (krypton, xenon, etc.) to flow into the main body 13, and the gaseous fission products (krypton, xenon, etc.) It is composed of an activated carbon packed layer 18 having adsorption and desorption performance, and an exhaust gas outlet nozzle 17 for flowing out radioactive gas waste to the outside of the main body cylinder 13.

The exhaust gas inlet / outlet nozzles 16 and 17 are the body cylinders.
It is detachable inside 13, and an upper manhole 19 is connected to the upper mirror 14, and the upper manhole 19 is closed by a manhole cover 20.

[0009]

Conventionally, in filling the activated carbon filling layer 18, an operator successively carries the small-divided bag-filled activated carbon from the manhole cover 20 into the main body cylinder 13,
It was filled up to the required filling amount.

For this reason, low work efficiency due to both the large amount of filling and the large amount of loading and filling work by small division packing, on the other hand, the necessity of the filling work in the body of the worker and the activated carbon There was a problem in the working environment due to dust generated during filling.

The present invention has been made to solve the above problems, and when the activated carbon, which is the filling material of the activated carbon type rare gas holdup device, is filled into the main body cylinder, the working efficiency of the activated carbon is improved and the filling is performed. It is an object of the present invention to provide an activated carbon type rare gas hold-up device capable of improving the working environment by preventing dust from being generated.

[0012]

The present invention is installed in a radiant gas waste treatment apparatus for treating radiant gas waste generated in a nuclear power plant or the like, and produces a gaseous fission product ( In an activated carbon type rare gas hold-up device in which activated carbon is filled in the body barrel for the purpose of achieving sufficient time decay of krypton, xenon, etc., activated carbon packages in which activated carbon is packaged are sequentially laminated in the body barrel. It is characterized by being filled with.

[0013]

In order to improve the work efficiency in filling the activated carbon, the activated carbon can be directly filled into the main body of the activated carbon type rare gas hold-up device without unpacking it so that it does not need to be unpacked.

Therefore, the activated carbon is packed in a cylindrical cloth shape corresponding to the inner diameter of the main body, that is, packaged, and a suspension ring is formed on the package, and the activated carbon sheet is used as the packaging material to reinforce the packaging material. And for packaging, the surface of the packing material is sewn with reinforcing sewing threads.

Then, the activated carbon is packaged by packing the activated carbon with a cylindrical cloth-like packaging material having a size corresponding to the inner diameter of the main body cylinder. As a result, when the main body is filled, it is deformed by its own weight during suspension. Therefore, the diameter of the filling manhole of the main body cylinder can be made sufficiently smaller than the inner diameter of the main body cylinder, and the state of being seated and filled in the main body cylinder has a predetermined cylindrical shape.

As a result, when the activated carbon package is filled in the main body, the activated carbon can be filled as it is without unpacking, so that the working efficiency of the filling work is improved and the activated carbon dust is prevented from improving the working environment. Can be achieved.

Further, between the inner surface of the main body and the activated carbon package, the inner surface of the main body and the activated carbon package are in close contact with each other due to the effect of their own weight, so that a gap between the inner surface of the main body and the activated carbon package is prevented. Can be achieved.

Therefore, the activated carbon package prevents the short bypass of the gaseous fission products (krypton, xenon, etc.), and there is no concern that the performance of the rare gas holdup will be deteriorated.

By forming the hanging ring for the hanging hook with the cloth-like packing material, the carrying-in can be carried in without providing a surrounding part or the like for newly handling the activated carbon package, thereby improving the handling property. Further, even if the activated carbon is replaced during the plant operation period, it can be handled in the same manner, so that the maintainability can be improved.

By using an activated carbon sheet as a packaging material for packaged activated carbon, the packaging material itself has an effect of retaining gaseous fission products (krypton, xenon, etc.). The load during transportation and filling of the packaged activated carbon is added to the reinforcing sewing thread.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the activated carbon type gas holdup device according to the present invention will be described with reference to FIGS.
1 shows the structure of the activated carbon type gas hold-up device of this embodiment, FIG. 2 shows the packaged activated carbon filled in the main body cylinder 13 of FIG. 1, and FIG. 3 shows the packaged activated carbon of FIG. It shows a state in which the main body barrel 13 is filled with.

That is, as shown in FIG. 1, the activated carbon type rare gas hold-up device 9a of this embodiment has a main body 13 and
The upper mirror 14 and the lower mirror 15 connected to the upper and lower ends of the main body 13
An exhaust gas outlet nozzle 16 and an exhaust gas inlet nozzle 17 provided in the vicinity of the upper mirror 14 and the lower mirror 15, and an upper manhole 19 and a manhole lid 20 provided on the upper mirror 14.
And an activated carbon package 21 filled in the body cylinder 13.

As shown in FIG. 2, the activated carbon package 21 has a cylindrical shape with a low height, and the outside is covered with an activated carbon sheet 23.
The inside is filled with activated carbon 24, the upper surface is sewn radially with a reinforcing sewing thread 25 to be reinforced, and a suspension ring 22 is provided in the central portion.

FIG. 3 is a view showing a state (working procedure) in which the main body cylinder 13 of the activated carbon type rare gas holdup device 9a is filled with the activated carbon package 21. Note that FIG. 1 shows an activated carbon type rare gas hold-up device in which filling of the activated carbon package 21 according to this embodiment is completed.

Therefore, according to the present embodiment, the activated carbon 24 having the adsorption / desorption effect of the gaseous fission products (krypton, xenon, etc.) due to the damage of the fuel rods, etc. is activated carbon sheet 23 as shown in FIG. In this case, the suspension ring 22 is formed so that it can be suspended by the suspension hook 26 shown in FIG.

Further, the activated carbon sheet 23 is sewn radially with the reinforcing sewing thread 25, the central portion thereof is bundled, and the suspension ring 22 is sewn.
To form. As a result, at the same time as forming the cylindrical packaging shape, reinforcement at the time of transportation and filling can be performed.

The activated carbon package 21 is suspended by a suspension hook 26, and is inserted and filled from the upper manhole 19 of the activated carbon type rare gas holdup device 9a. It is necessary to remove the exhaust gas outlet nozzle 16 in advance during this work.

Since the activated carbon package 21 is deformed into a rugby ball shape by its own weight as shown in FIG. 3, the inner diameter of the upper manhole 19 can be made smaller than the inner diameter of the main body cylinder 13.

The above working procedure is repeated to sequentially fill the activated carbon package 21, and after filling the required amount of activated carbon package 21 as shown in FIG. 1, the exhaust gas outlet nozzle 16 previously removed is attached to the manhole. lid
The filling work is completed by attaching 20. The state of the activated carbon type rare gas hold-up device 9a in which the filling work is completed has a structure as shown in FIG.

FIG. 4 (a) shows an activated carbon package 21a according to another embodiment of the present invention, and FIG. 4 (b) shows another example of the activated carbon package 21b. The other embodiment of the present invention is almost the same as the first embodiment except for the activated carbon packages 21a and 21b, and the description thereof will be omitted.

In the above embodiment, activated carbon package
Although 21 is a cylindrical cloth-like packing, it may be a semi-cylindrical shape as shown in FIG. 4 (a) or a fan shape divided into 1/4 as shown in FIG. 4 (b).

That is, FIG. 4 (a) shows an activated carbon package 21a which is formed in a semi-cylindrical shape by an activated carbon sheet 23, has a hanging ring 22 in the center, and the activated carbon sheet 23 is filled with the activated carbon 24 to form a reinforcing sewing thread. It is sewn radially by 25 and packaged. To reinforce the activated carbon sheet 23,
As a substitute for the reinforcing sewing thread 25 that is sewn radially,
The activated carbon package may be covered with a mesh bag.

Activated carbon package 21b in FIG. 4 (b)
Is a fan-shaped tubular body formed by dividing a cylindrical body into quarters, and the other parts are the same as those in FIG.

[0034]

EFFECTS OF THE INVENTION According to the present invention, activated carbon is packaged so that it can be filled as it is at the time of filling without unpacking, thereby improving work efficiency of filling work and preventing generation of activated carbon dust. The effect of environmental improvement can be obtained.

Further, since the activated carbon is packaged in the cylindrical cloth packing material having a size equivalent to the inner diameter of the main body, no void is generated between the inner surface of the main body and the activated carbon package, and as a result, the gas Fission products (krypton,
Xenon, etc.) will not short bypass.

Further, since the activated carbon sheet is used as the packing material for the activated carbon, the packing material itself has an effect of retaining the gaseous fission products, and as a result, there is no fear of deterioration of the performance in the rare gas holdup.

Further, since the upper part of the activated carbon package is formed in the shape of a hanging ring for a hanging hook by the cloth-like packing material, handling and maintenance are improved, and
The load during transportation and filling of the activated carbon package itself is added to the reinforcing sewing thread. As a result, the strength condition required for the activated carbon sheet is reduced, and it becomes easy to form an activated carbon package having a structure suitable for the inside of the main body cylinder.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of an activated carbon type rare gas holdup device according to the present invention in a partial longitudinal section.

FIG. 2 is a perspective view showing an activated carbon package filled in the main body cylinder in FIG.

FIG. 3 is a side view showing, in a partial cross section, a state in which an activated carbon package is filled in the main body cylinder in FIG.

4A is a perspective view showing an activated carbon package in another embodiment of the activated carbon rare gas holdup device according to the present invention, and FIG. 4B is a perspective view showing another example of the activated carbon package in FIG. 4A. .

FIG. 5 is a system diagram showing a basic system configuration of a radioactive gas waste treatment device.

FIG. 6 is a side view showing a part of a conventional activated carbon type rare gas holdup tower in a vertical cross section.

[Explanation of symbols]

1 ... Main condenser, 2 ... Steam type air extractor, 3 ... Exhaust gas preheater, 4 ... Exhaust gas recombiner, 5 ... Exhaust gas condenser, 6 ... Exhaust gas precooler, 7 ... Exhaust gas dryer, 8 ... Previous Static filter, 9,
9a ... Activated carbon type rare gas hold-up device, 10 ... Exhaust gas particle filter, 11 ... Exhaust gas vacuum pump, 12 ... Exhaust tube, 13
… Main body, 14… Upper mirror, 15… Lower mirror, 16… Exhaust gas outlet nozzle, 17… Exhaust gas inlet nozzle, 18… Activated carbon packed bed, 19… Upper manhole, 20… Manhole cover, 21, 21a, 21b… Activated carbon package , 22 ... Suspension ring, 23 ... Activated carbon sheet, 24 ...
Activated carbon, 25… Reinforcing sewing thread, 26… Hanging hook.

Claims (5)

[Claims] 1. A gaseous fission product (krypton, krypton, etc.) installed in a radioactive gas waste treatment device for treating radioactive gas waste generated in a nuclear power plant etc.
In the activated carbon type rare gas hold-up device with activated carbon filled in the main body for the purpose of sufficient time decay of xenon, etc., activated carbon packages in which the activated carbon is packaged are sequentially laminated in the main body. Activated carbon type rare gas hold-up device characterized by being filled. 2. The activated carbon type rare gas hold-up device according to claim 1, wherein the activated carbon package is formed by packing activated carbon in a cylindrical cloth packing material having a dimension corresponding to an inner diameter of the main body cylinder. 3. The activated carbon type rare gas hold-up device according to claim 1, wherein a suspension ring for a suspension hook is formed on the upper surface of the activated carbon package with the same material as the packaging material. 4. The activated carbon type rare gas hold-up device according to claim 1, wherein the material of the activated carbon package is an activated carbon sheet. 5. The activated carbon type rare gas hold-up device according to claim 1, wherein at least one surface of the activated carbon package is sewn and reinforced by radial sewing threads for reinforcement.