JPS599596A - Cask handling method and double vessel used for it - 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 method for handling IJ, , and L yasks, that is, spent fuel transport containers, in contaminated water, and a double container used therein. This article relates to a method in which the cask is wrapped in an outer container, and when the cask is excavated into the air, the outer container is left in the water and the cask is wrapped in an inner container that does not come into contact with contaminated water, and the container used for this purpose. be.

The work of storing spent fuel in a cask and removing spent fuel from a cask is normally performed in a pool by remote control. The water in the pool is radioactively contaminated by these operations, so if the cask is placed directly into the pool, the surface of the cask will be contaminated. This cask is equipped with a large number of heat dissipation fins on its surface to increase its heat dissipation ability, so cleaning it when it is pulled out of the pool and decontaminating it after it is lifted is extremely difficult and requires a large amount of man-hours. If you need it, please contact us.

Therefore, conventionally, methods that can solve these problems to some extent include bagging v1, in which the cask is wrapped in vinyl, rubber, canvas, etc., and submerged in the pool, or the cask is stored in a steel container and placed in the pool. There are storage methods such as submersion, but in all of these methods, bags or containers whose surfaces are contaminated due to contact with contaminated water are aerated into the work space when the cask lid is lifted, causing air pollution! Problems such as I-stiffness and floor contamination caused by falling contaminated water droplets have not yet been solved.

The purpose of the present invention is to eliminate the problems inherent in the above-mentioned conventional techniques, and to provide a GiX/Suffel plate that has extremely excellent contamination prevention performance when handling casks in water contaminated with water. The object of the present invention is to provide a new method and a container for each.

The present invention, which was devised to achieve this object, wraps the Kitosk in a double container consisting of an inner container and an outer container, and when lifting the Kitsuf in the air, the outer container is left in the water. It is recommended that the treatment be carried out in an inner container that will not come into contact with contaminated water.

Hereinafter, the present invention will be explained in more detail based on the drawings. The cask lid filling method according to the present invention includes the following steps. In other words, as shown in Figure 1,
Outside the pool, there are a step of storing the cask 10 in the open content a12 with its body portion 11 exposed, a step of sealing and covering the gap between the outer wall of the cask 10 and the inner container 12, and The inner container 12 is stored in a lidless outer container 15 that is arranged in a shallow area 13 so that the upper opening edge protrudes above the pool water surface 14, with the cask lid 11 kept exposed, and A step of sealing the outer container 15 and the inner container 12, and a double container of the former inner container 12 containing the cask 10 and the outer container 15,
The cask 10 is transported to the deep area 16 of the pool where it is completely submerged under water, and the lid 11 of the cask 10 is opened and closed.
The process of loading and unloading articles into and out of the eel pool, and then transferring the double container with a built-in cask to the shallow area 13 of the eel pool, where the upper opening edge of the outer container 15 is located above the water surface 9-. The process includes the steps of leaving the guest container 15 in the shallow area 13, carrying out the inner container 12 containing the cask 10 outside the pool, and taking out the cask 10 from the inner container 12 outside the pool.

In addition, in the present invention, each T culm does not necessarily need to strictly follow the order of the passage of time.

For example, -1: The gap between the yask 10 and the inner container 12 is normally sealed outside the pool, but it may also be done after the yask 10 and the inner container 12 are housed in the outer container 15 in the shallow area 13 of the pool. If a J: Eel inflate gasket, which will be described later, is used for this sealing, install the infrastructure 1 ~ gas shoes 1 ~ outside the pool and store them in the outer container 15 in the shallow area 13 of the pool. After that, it is possible to finally achieve a completely sealed state.

In the embodiment shown in FIG. 1, the gap between the cask 10 and the inner container 12 is sealed by tightening the annular restraining plate 19-1 r) through the gasket 17 at the open end L. - I can do what I want to do.

The gap between the inner container 12 and the outer container 15 is sealed by connecting the inner container's joint 7 between the flange 12a and 15a to the gasket 1 that holds the flexible tube 1:1-V screen 10. and compressed by the load m of the inner container 12 etc. J: is n4
- Therefore, in this case, there is no need for tightening and eye-pupping operations. In addition, compressed air, pure water, etc. are supplied to each person in the gap between these doubles as necessary.

After loading and unloading articles into and out of the cask 10 in the deep area 16 of the pool, when pulling the items into the shallow area 13 of the pool, or after pulling them up, the body part 11 and the upper part of the gear suffix are placed in the cask by J for washing etc. Priority decontamination work will be carried out.

In this 4T cask handling method, the outer container that comes into contact with contaminated pool water is always kept in the pool and is not transferred through the work area, reducing contamination of the work area and transferring it to the inner container. Storage of the cask is carried out in the work area outside the pool, making it safe and reliable.In addition, the inner cask can be hung from the pool as a cask, making draining easier. It has an excellent effect such as being able to shorten the period between '1' and the like.

Next, we will discuss suitable equipment for carrying out the method of the present invention.
1 This will be explained with reference to FIGS. 2 and 3.

The apparatus used here is similar to the one shown in FIG. 1, and consists of a double container, one inside and one outside. 7
1-'+*That is, it is cylindrical with a lidless bottom, has an outward joint flange 12a at the upper part, and has an inner container 12 that can accommodate the =l: ty disk 10, and a cylindrical shape with a lidless bottom. The outer container 15, which can accommodate the inner container 12, and the inner container 1, with the upper end opening facing outward joining flange 15a on the right side.
infrastructure 1 attached to the periphery of the upper end opening of cask 10 and intervening between it and the upper part of the cask 10 to seal the gap therebetween;
The gasket 20 includes an annular gasket 18 interposed between the joining flanges 12a and 15a of the inner container 12 and outer container 15.

As shown in detail in FIG. 3, each of the infrastructure 1 to gasket 20 has an inner groove-shaped inflate duplex 22 connected to one peripheral edge of an annular rubber plate 21. None, 1 step with a gap on the circumference of the upper part of the cask [)
two inflated duplex support plates 23a,
The inflate-11-b 22 is held between U1 and PM clothes of the inflate duplex 22, and
Tightening is performed when the band 24 brings the lower end of the annular rubber plate 21 into close contact with the outer peripheral surface of the inner container 12, thereby sealing the gap between the first yask 10 and the inner container 12. By the way, there are many IMs on the outer peripheral surface of the cask 10 in order to improve the heat dissipation effect.
Since the thermal rough-in 25 is attached (pushed), the top two of the heat radiation fins 25 can be used as the two inflate/dupe support plates, and the existing cask can be used as is, which is advantageous.

The inflated duplex 22 expands by forcing water into its interior, and comes into close contact with the upper part of the disk 17. For this reason, the inflate duplex 22 is provided with a pressurizing quick connector 27 and a venting quick connector 28. In addition, the cask 10 and the inner container 12
13- In order to fill the gap with fresh water, a quick connector 29 for supplying fresh water is provided on the annular rubber plate 21.

This work of fixing the gap is carried out as follows. First, the inflate dupe 22 is inserted between the inflate tube support plates 23a and 2311 of the cask 10, and the lower end edge of the annular rubber plate 21 is tightened (fixed 11 with the band 24) to the upper end opening edge of the inner container 12. next,
Fresh water is injected into this gap from the fresh water supply quick connector 29, and when the gap becomes full, the water injection is stopped. Then, open the automatic closing quick connector 28 for inflate, dupe, and vent, inject fresh water from the pressurizing quick connector 27, and connect the vent quick connector 2.
8, the quick connector is closed, and then water is forced in from the pressurizing quick connector 27 to expand the inflate dupe 22 and complete the seal. In addition, if a vent valve (not shown) is provided separately on the annular rubber plate 21, the sealing can be completed by first inflating the inflator 14-lard-bucove 22! ,
It is possible to simultaneously or subsequently inject fresh water into the gap between the cask and the inner container.

The density J1 of the gap between the inner container 12 and the outer container 15 is the same as that described in connection with FIG. 1, and water is filled inside. In that case, the annular gasket]・18 is preliminarily attached to the outer container 1.
It is preferable to attach it to the upper surface of the joint 7 flange 15a of No. 5 because the work becomes easier.
2 is made of stainless steel with a smooth surface, making it easy to clean afterwards.

The outer container 15 is designed with a &! (not shown in the figure) is desirable. Also, when lifting the inner container 12 while leaving the outer container 15 in the shallow area of the pool, the inner and outer containers should be It is preferable to install a pressurized fluid supply port (not shown) so that pressurized fluid can be supplied between the two.

Furthermore, in the present invention, the first head tank 30 provided at a high place
By connecting infrastructure 1 to Jiko 122 through distribution @ 32, a constant pressure higher than the external pressure is applied regardless of the water depth. 10 and the inner container 12 and the second head tank 33, which is placed at a high place, are communicated with the piping 34, so that the water depth can be maintained at a constant value or from external pressure. In this case, the water pressure J in the gap is made higher than the internal pressure in the tubes 22. Therefore, the first head tank 30 is Either the second head tank 33 is installed at a higher location, or the water surface in the first head tank 30 is pressurized using compressed air. Regardless of the situation, since a pressure that is always a certain value higher than the external pressure is applied, it is possible to completely prevent pool water from penetrating.

Hereinafter, the present invention has been described in detail, but in order to make it easier to understand, the explanation will be given over time, taking the case of spent nuclear fuel removal as an example. <-g oh,
This is just an example, and the work order does not necessarily have to be as shown, and the points that are similar to the description of the previous embodiment mean that the work order may be changed.

The main 11 tank 10 that was transported to the reprocessing site for reprocessing and pumping had its upper and lower buffers removed, as shown in Figure 4A:
'rj'/screen is placed in the inner container 12 in the decontamination chamber 40. Inside the cask decontamination chamber 40, the cask internal pressure is opened from the vent valve, and the cask internal cooling water is replaced with pure water. Next, as shown in FIG. 8, 4: After filling the space between the yask and the inner container 12 with pure water, the inflate gasket 20 is attached. Then, after removing the cask lid bolt and installing the lid adapter 41, the inner container hanging tool 49 is
Then, it is lifted up by the crane 42 and transferred to the fuel removal pool (see C in the same figure).

As shown in the figure 1-, shallow area 13 in the fuel removal pool.
The inner container 12 with the built-in key 17-A/Suph was lowered into the outer container 15 located at rear,
Supply pressurized pure water to the inflated gaskets 1 to 20 and seal them. Next, as shown in FIG. 13, (1) the suspension arm '1.3 is used to transport it to the deep area 16 of the pool. Now, as shown in the same figure, take out the swallow (4i11) with the cask lid hanger 44, take out the fuel 46 from the -1:yask with the fuel gripping tool of the fuel removal pool crane 45, and remove the fuel storage tank 1. 48. Then, the fuel storage basket 48 is placed on the underwater truck and transferred to the fuel storage pool.

The empty cask, inner container, and outer container from which the fuel has been taken out are roughly decontaminated in a pure water shower 47 and placed in the shallow area of the pool 1.
3. (See G in the same figure) 3. The cask body was also decontaminated with a shower of pure water, and the lid was placed on the cask. and,
Disconnect the pure water supply hose and attach the inner container hanger/I9 (see Figure 11). Next, as shown in FIG.
5 in the pool, and the inner container 12 with a built-in cask =
18= After hanging, I-ge, and draining thoroughly, Kitosk decontamination room/4
Return to 0.

After that, inside the cask decontamination chamber 40, remove the inner container hanger 49 and the lid adapter, tighten the lid bolts, and after decontaminating the top of the E-Ro 11 cask, remove the inflate gasket. Drain the water inside the inner container and the cask, pull out the cask from the inner container, and decontaminate the surface of Ki17. After Wf confirms that there are no leaks in the cask seal, permission for removal is obtained through a survey by radiation control personnel, and the material is transported outside.

In this way, spent fuel can be removed. It would be nice to do the same thing when putting in spent fuel.

The present invention uses a double container consisting of an inner container and an outer container as described above, and removes the cask and the inner container while leaving the outer container, which occupies most of the surface that came into contact with radioactively contaminated water, in the water. This structure significantly reduces air and floor contamination, and also prevents water droplets from the lid that come into contact with contaminated water from adhering to the surface of the cask cooling fins, eliminating the need for decontamination. 1 - The area of the space can be significantly reduced by 1↓.

Furthermore, since the cask is stored in the inner container outside the pool, the work is safe and reliable.Also, since the cask with the inner container is lifted from the pool, water can be drained easily and the operating time can be shortened.

In addition, various improvements have been made to the device, so
Overall, it has far superior effects compared to conventional technology, such as improved safety and work efficiency.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the method of the present invention, FIG. 2 is an explanatory diagram of the usage state using the double container according to the present invention, and FIG. 3 is an enlarged sectional view of the part indicated by the symbol ■ in FIG. FIG. 4 is an explanatory diagram showing an example of the work procedure. 10...Ki1t disk, 11...Lid body, 12...Inner container, 13...Pool shallow area, 14...Water surface, 15...
... Outer container, 16... Pool deep area, 17.1'8...
·gasket. Figure 4A -503- Figure 4B Figure 4E Figure 4F Figure 4G Figure 4H Figure 4I

Claims (1)

[Claims] 1. Storing the cask in an open inner container outside the pool with its lid portion exposed; Sealing the gap between the outer wall of the cask and the inner container; In a shallow area of a pool, the inner container is stored in an open outer container that is arranged so that its edge protrudes below the water surface, with the cask lid body being kept exposed; and a culm that seals between the outer container and the inner container; The double container containing the cask is transferred to the deep part of the pool where the entire cask is submerged under water, where the lid of the cask is opened and closed. Step of loading and unloading items into and out of the storage space; After that, the double container with a built-in key and suction cup is
The process of transferring to a shallow part of the pool where one end edge is above the water surface; leave the outer container in the shallow part, carry the cask and inner container out of the pool, and take out the cask from the inner container outside the pool. Process: A cask handling method characterized by having the following steps. 2. Claim 1, in which the gap between the outer wall of the cask and the inner container is sealed using an inflated gasket.
The method described in section. 3. The inflate gasket has a structure in which an inflate duplex is connected to one periphery of an annular rubber plate.
2, numbers are placed at intervals on the circumference of the upper part of the cask.
The infrastructures 1 to dupes are held between two inflate dupes supporting plates, and the gap between the outer wall of the cask and the inner container is sealed by the expansion 111 of the inflate dupes and the annular rubber plate's close contact with the inner container. The method according to claim 2. 4. The method according to claim 3, wherein the two infra-1/dupe support plates are two of the R-1 portion of the cold rim 1) fin provided in the cask. 5. Infra-1-・Expansion of the tube, Infra-1
～・Special i′ performed by pressurizing water into the tube
F. The method according to claim 2, 3, or 4. 6. Water 1f in the infrastructure-1 to tube is applied by connecting the tube to the first head tank provided at a high place and the infrastructure-1 through piping.Claim 5 Method described. 7. The method according to claim 1, 2, 3, 4, 5, or 6, wherein water is poured into the gap between the inner container and the kitosuku. 8. The method according to claim 7, wherein water is not injected into the gap between the cask and the inner container into a second head tank provided at a high place. 9. The water pressure in the gap between the cask and the inner container is applied by carefully connecting the first head tank installed at a high place and the gap.
The method described in section. 10. A patent in which the gap between the inner container and the outer container is sealed by a flexible gasket interposed between the joint flange of the inner container, which is compressed by the load of the 1.1-yask and the inner container. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, or 9. 11. The method according to claim 10, wherein water is sealed in any gap between the inner container and the outer container. 12. The method according to claim 10, wherein fluid is pressurized into the gap between the two chambers when the inner container is pulled out from the outer container. 13. Claims 1, 2, 3, and 4, in which decontamination work is performed with emphasis on the cask lid portion in a step after loading and unloading articles into and out of the cask.
Section 5, Section 6, Section 7, Section 8, Section 9, Section 10,
The method according to item 11 or 12. 14. The method according to claim 13, in which the decontamination work is water washing, v1゜15. The container is cylindrical with an open bottom, has an outward joining flange at the top, and is capable of storing a cask inside. Inner container, etc.; An outer container, etc., which is cylindrical with an open bottom and has an outward joining flange at the upper end opening, and can accommodate the inner container; Attached to the periphery of the upper end opening of the inner container, and attached to the upper part of the cask. An infrastructure 1 which can seal the gap between the inner container and the outer container; Double container for cask handling. 16. The infra-1 ~ gasket has a structure in which a tube is connected to the infra-1 on one side of the circumference of the annular rubber plate, and the in-flat tube is spaced at intervals of 5--1-1 nosks in the lateral direction. 2
16. The double container according to claim 15, wherein the annular rubber plate can be attached between the two inflate/dup support plates, and the annular rubber plate can be attached to the outer periphery of the upper opening of the inner container by a tightening J-band. 17.To infrastructure-1・The tube and the annular rubber plate are
18. The double container according to claim 15 or 17, wherein each of the double containers is provided with a pressurized fluid supply port. 18. The double container according to claim 15, wherein the outer container has a 1c th trough to prevent floating. 19. The double container according to claim 15, wherein the inner container is made of stainless steel with a smooth surface. 20. The double container according to claim 15, wherein the annular gasket is mounted on the upper surface of the joining flange of the outer container. 21. The double container according to claim 15, wherein the outer container is provided with a pressurized fluid supply port for easily drawing out the inner container from the outer container. 6-