TWI572854B - Device for Detecting Integrity of Sealed Border of Dry Storage Container of Used Nuclear Fuel during Operation Period - Google Patents

Description

Device for detecting seal boundary integrity of used nuclear fuel dry storage container during operation

The present invention relates to a device for detecting the boundary integrity of a used nuclear fuel dry storage container during operation, and more particularly to a detection device using an external convection blocking device, a gas sampling and analysis device, in particular, by external convection The equipment will use the nuclear fuel dry storage system or its internal clearance area, temporarily isolate from the natural environment to define an isolation space, and extract or sample the gas in the isolated space to confirm the sealed boundary of the used nuclear fuel dry storage container. Integrity, which in turn enhances storage safety.

The used nuclear fuel dry storage container is placed in the outer package of the used nuclear fuel dry storage container, and the stored large amount of radiation emitted by the used nuclear fuel causes the non-destructive detection method commonly used in the industry to be It is applied to the inspection of the surface of the used nuclear fuel dry storage container for damage caused by corrosion, so the integrity of the sealing boundary cannot be confirmed. At present, the monitoring or inspection techniques proposed by the industry, such as temperature monitoring, humidity monitoring, pressure monitoring, and environmental salt spray monitoring, can only provide reference information on the degree of deterioration of the sealing boundary material. In addition, industrial endoscopes have been used. The exhaust port of the outer package of the nuclear fuel dry storage container is inserted to visually check whether the surface of the used nuclear fuel dry storage container has corrosion marks, and it can only be determined whether the sealed boundary of the used nuclear fuel dry storage container has occurred. Corrosion, and it is impossible to check whether the seal boundary is damaged and whether a leak has occurred. The designed service life of the used nuclear fuel dry storage system is generally more than 40 years, so it is difficult to avoid the deterioration of the material used in the nuclear fuel dry storage container or the corrosion of the surface. However, if only the material is found to have a tendency to deteriorate or the surface is corroded, that is, the sealing boundary is damaged, the storage cost will be greatly increased, and the unnecessary use of the nuclear fuel dry storage container replacement operation may be performed; or, if the sealing boundary is found If damage occurs but it is determined that only corrosion occurs on the surface, it may cause the escape of radioactive materials, which in turn affects the storage safety of used nuclear fuel. Therefore, the user can not meet the requirements of the user to effectively meet the seal boundary integrity of the used nuclear fuel dry storage container during the actual confirmation operation.

The main object of the present invention is to overcome the above problems encountered in the prior art and to provide a dry storage container for use in spent nuclear fuel without destroying or affecting the safe storage of the used nuclear fuel dry storage system. The detection of the concentration or leak rate of helium or possibly radioactive gas outside the container serves as a means of determining the integrity of the sealed boundary of the used nuclear fuel dry storage container. For the purpose of the above, the present invention is a device for detecting the boundary integrity of a spent nuclear fuel dry storage container during operation, comprising: an outer package of a used nuclear fuel dry storage container, comprising at least one air inlet, An air outlet, a structural body and a top cover, and the structure body has an accommodating space, the accommodating space is connected with the air inlet and the air outlet; and a nuclear fuel dry storage container is used. The system is disposed in the outer package of the used nuclear fuel dry storage container to form a used nuclear fuel dry storage system, and the spent nuclear fuel dry storage container outer package and the used nuclear fuel dry storage container have a gap region; an external convection blocking device is coupled to the outer package of the used nuclear fuel dry storage container, the external convection blocking device comprising at least a body unit and a sampling unit for using the used nuclear fuel The dry storage system or its interstitial area is isolated from the natural environment to define an isolated space and to conduct gas in the isolated space Taking or sampling; and a gas sampling and analysis device coupled to the external convection blocking device, the gas sampling and analysis device comprising at least one extraction or sampling unit and an analysis unit for detecting the isolated space The helium leak rate, the helium gas concentration, or the radioactive gas concentration are used as the basis for judging the seal boundary integrity of the used nuclear fuel dry storage container. In the above embodiment of the present invention, the external convection blocking device is a gas collecting cover, the body unit is a gas collecting cover body, and the sampling unit is a sampling pipe, and the gas collecting cover is installed on the used nuclear core. The fuel dry storage container is outside the outer package and is spaced apart from the outer package of the used nuclear fuel dry storage container, and the insulating space is formed between the gas collecting cover, the structural body and the top cover. In the above embodiment of the present invention, the lower end of the hood body is in contact with the storage floor substrate. In the above embodiment of the present invention, the gas collecting hood is represented by a completely coated nuclear fuel dry storage system and capable of isolating the contact between the used nuclear fuel dry storage system and the natural environment. In the above embodiment of the present invention, the gas collecting hood is capable of completely covering the spent nuclear fuel dry storage system and is capable of isolating the used nuclear fuel dry storage system, in addition to the bottom of the used nuclear fuel dry storage system. A manifestation of the form of contact between natural environments. In the above embodiment of the invention, the sampling line is in the form of an open and closed function. In the above embodiment of the present invention, the external convection blocking device is a cover plate, the body unit is a cover body, and the sampling unit is a sampling joint, and the cover plate is installed and covered in the used nuclear fuel dry type. The air inlet and the air outlet of the outer package of the storage container are disposed, and the insulating space is formed between the cover, the air inlet and the air outlet. In the above embodiment of the invention, the cover is represented by a partially coated spent nuclear fuel dry storage system and is capable of isolating the contact between the gap region of the used nuclear fuel dry storage system and the natural environment. In the above embodiment of the invention, the sampling joint is in the form of an open and closed function. In the above embodiment of the present invention, the used nuclear fuel dry storage container is placed in the accommodating space of the structure body of the outer package of the used nuclear fuel dry storage container.

Please refer to FIG. 1 for a schematic cross-sectional view showing the structure of the first embodiment of the present invention. As shown in the figure: the present invention is a device 100 for detecting the boundary integrity of a spent nuclear fuel dry storage container during operation, comprising a used nuclear fuel dry storage container outer package 1, and a used nuclear fuel dry storage container. 2. A gas collecting hood 3 and a gas sampling and analysis device 4. In the present embodiment, the gas collecting hood 3 is used as an external convection blocking device. The above-mentioned nuclear fuel dry storage container outer package 1 comprises at least one air inlet 11, an air outlet 12, a structural body 13 and a top cover 14, and the structure body 13 has an accommodation therein. The space 131 is connected to the air inlet 11 and the air outlet 12 . The used nuclear fuel dry storage container outer package 1 is used for placing the used nuclear fuel dry storage container 2 to shield the radiated radiation thereof, and the outer surface of the outer package 1 of the used nuclear fuel dry storage container is provided The air inlet 11 and the air outlet 12 are provided to generate natural convection, and the decaying tropical water generated by the used nuclear fuel stored in the used nuclear fuel dry storage container 1 is discharged into the natural environment, thereby avoiding the use. The nuclear fuel dry storage container 2 is damaged by overheating, causing leakage of radioactive materials. The used nuclear fuel dry storage container 2 is placed in the outer package 1 of the used nuclear fuel dry storage container to form a used nuclear fuel dry storage system, and the used nuclear fuel dry storage container outer package 1 and The used nuclear fuel dry storage container 2 has a gap region 5 therebetween. The used nuclear fuel dry storage container 2 is used for storing used nuclear fuel to avoid leakage of radioactive materials. During storage, the inside of the used nuclear fuel dry storage container 2 is an inert atmosphere filled with helium gas to avoid deterioration of the used nuclear fuel jacket and the interior of the storage container. The gas collecting cover 3 is installed outside the outer package 1 of the used nuclear fuel dry storage container, and is spaced apart from the outer package 1 of the used nuclear fuel dry storage container, and the gas collecting cover 3 contains at least one set. The hood body 31 is formed with a sampling line 32, and an insulating space is formed between the gas collecting hood 3, the structural body 13 and the top cover 14. The gas sampling and analysis device 4 is coupled to a sampling line 32 of the plenum 3, the gas sampling and analysis device 4 comprising at least one extraction or sampling unit 41 and an analysis unit 42. Thus, by the above disclosed structure, a completely new apparatus for detecting the boundary integrity of a used nuclear fuel dry storage container during operation is constructed. The gas collecting hood 3 is expressed in any form that can completely coat the spent nuclear fuel dry storage system and can isolate the use of the spent nuclear fuel dry storage system from the natural environment. The gas collecting hood 3 is in addition to the bottom of the used nuclear fuel dry storage system, and is capable of completely covering the used nuclear fuel dry storage system and is capable of isolating the use of the used nuclear fuel dry storage system from the natural environment. Formal expression. The sampling line 32 of the above-mentioned gas collecting hood 3 can be expressed in any form having an opening and closing function. When in use, the present invention places the used nuclear fuel dry storage container 2 in the accommodating space 131 in the structural body 13 of the outer package 1 of the used nuclear fuel dry storage container, the hood 3 Installed on the outer side of the outer package 1 of the used nuclear fuel dry storage container, the lower end of the gas collecting cover body 31 is in contact with the storage ground substrate 6, and the used nuclear fuel dry storage system is isolated from the natural environment to define an isolation. The space ensures that the helium or radioactive gas leaking from the sealed boundary of the used nuclear fuel dry storage container 2 does not escape into the natural environment, and accumulates in the isolated space inside the collecting hood 3. Since the density of the helium gas is lower than the normal air density, the helium gas leaking from the sealed boundary of the used nuclear fuel dry storage container 2 accumulates on the top of the gas collecting hood 3, and a very small amount of radioactive gas can be The gas sampling and analysis device 4 detects that the sampling line 32 is disposed at the top of the gas collecting hood 3 for extracting or sampling the gas in the isolated space at the top of the gas collecting hood 3, and detecting the space in the isolated space. The helium leak rate, the helium gas concentration, or the radioactive gas concentration are used as the basis for judging the seal boundary integrity of the used nuclear fuel dry storage container 2. The sampling line 32 can block the contact between the interior of the gas collecting hood 3 and the natural environment during non-extraction or sampling; during the extraction or sampling, the extraction or sampling unit 41 can extract or sample the gas collection. The gas in the space in the top of the cover 3 is used by the analysis unit 42. Please refer to FIG. 2, which is a cross-sectional view showing the structure of a second embodiment of the present invention. As shown in the figure, the device 100a for detecting the boundary integrity of the used nuclear fuel dry storage container during the operation of the present invention may be configured in another embodiment in addition to the above-mentioned configuration. The difference is that the cover 7 is used as an external convection blocking device. The cover plate 7 is installed and covered on the air inlet 11 and the air outlet 12 of the outer package 1 of the used nuclear fuel dry storage container, and the cover 7 includes at least a cover body 71 and a sampling joint 72. The cover plate 7, the air inlet 11 and the air outlet 12 form an insulating space. The cover plate 7 is in any form that is coated with a spent nuclear fuel dry storage system and is capable of isolating the contact between the gap region of the used nuclear fuel dry storage system and the natural environment. The sampling joint 72 of the cover plate 7 described above can be expressed in any form having an opening and closing function. When in use, the present invention places the used nuclear fuel dry storage container 2 in the accommodating space 131 in the structural body 13 of the outer package 1 of the used nuclear fuel dry storage container, and the cover 7 is installed and Covering the air inlet 11 and the air outlet 12 of the outer package 1 of the used nuclear fuel dry storage container. When the air inlet 11 and the air outlet 12 are closed by the cover 7, the structural body 13 and the top cover 14 of the outer package 1 of the nuclear fuel dry storage container are matched, and the used nuclear fuel dry type can be prevented. The helium or radioactive gas leaking from the sealed boundary of the storage container 2 is dissipated into the natural environment, and the isolated space accumulated in the gap between the outer package 1 of the used nuclear fuel dry storage container and the used nuclear fuel dry storage container 2 . The cover plate 7 is provided with the sampling joint 72 for extracting or sampling the gas in the isolated space defined by the gap between the outer package 1 of the used nuclear fuel dry storage container and the used nuclear fuel dry storage container 2. The helium leak rate, the helium gas concentration, or the radioactive gas concentration in the isolated space are detected as a basis for judging the seal boundary integrity of the used nuclear fuel dry storage container 2. The cover body 71 is provided with a pipe connecting the gap region and the sampling joint 72. Wherein, the sampling joint 72 can prevent contact between the gap region and the natural environment during non-extraction or sampling; during the extraction or sampling, the extraction or sampling unit 41 can extract or sample the gas in the isolated space of the gap region. For use by the analysis unit 42. Accordingly, the present invention is directed to a device for detecting the boundary integrity of a used nuclear fuel dry storage container during operation of a spent nuclear fuel dry storage yard, wherein the used nuclear fuel dry storage container 2 is placed in a used nuclear fuel dry type. After the storage container outer package 1 constitutes a used nuclear fuel dry storage system, the used nuclear fuel dry storage system or the used nuclear core is utilized by the gas collecting cover 3 or the cover plate 7 and the gas sampling and analysis device 4. The gap between the fuel dry storage container outer package 1 and the used nuclear fuel dry storage container 2 is temporarily isolated from the natural environment to define an isolation space to ensure leakage from the sealed boundary of the used nuclear fuel dry storage container 2. The helium or radioactive gas does not escape into the natural environment. In the allowable full clogging time allowed by the dry storage system safety analysis report, the internal temperature and pressure of the used nuclear fuel dry storage container 2 are forced to rise under control in a manner that blocks natural convection cooling, if used If the sealed boundary integrity of the nuclear fuel dry storage container 2 has been caused by material degradation or corrosion, the internal gas of the used nuclear fuel dry storage container 2 will be released into the isolated space, and the gas sampling and analysis device 4 of the extraction or sampling unit 41, the sampling hood 3 on the plenum 3 or the sampling joint 72 on the cover 7, the top of the plenum 3 or the outer package of the used nuclear fuel dry storage container 1 extracting or sampling a gas in an isolated space of the gap region between the spent nuclear fuel dry storage containers 2, and the analyzing unit 42 detects whether the helium leak rate, the helium gas concentration or the radioactive gas concentration in the isolated space is abnormal. , as a basis for judging whether or not the sealed boundary of the used nuclear fuel dry storage container 2 is leaked, thereby determining the Seal integrity of the borders. In summary, the present invention is a device for detecting the boundary integrity of a spent nuclear fuel dry storage container during operation, which can effectively improve various disadvantages of the conventional use, and is a gas collecting cover capable of covering a used nuclear fuel dry storage system or The cover of the inlet and outlet ports of the outer package of the used nuclear fuel dry storage container can effectively confirm the detection of the integrity of the sealed boundary of the spent nuclear fuel dry storage container during operation, thereby enabling the production of the present invention to be more Progress, more practical, and more in line with the needs of users, it has indeed met the requirements of the invention patent application, and filed a patent application according to law. However, the above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto; therefore, the simple equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the invention are modified. All should remain within the scope of the invention patent.

100, 100a‧‧‧ Devices for detecting the boundary integrity of used nuclear fuel dry storage containers during operation 1‧‧‧Using nuclear fuel dry storage container external package 11‧‧‧Air inlet 12‧‧‧Outlet 13 ‧‧‧Structural body 131‧‧‧ accommodating space 14‧‧‧Top cover 2‧‧‧Used nuclear fuel dry storage container 3‧‧‧Gas hood 31‧‧‧ Collector cover 32‧‧‧Sampling tube Road 4‧‧ Gas sampling and analysis equipment 41‧‧‧ Extraction or sampling unit 42‧‧‧ Analysis unit 5‧‧‧Gap area 6‧‧‧ Storage ground floor 7‧‧‧ Cover 71‧‧‧ Cover Body 72‧‧‧Sampling connector

Fig. 1 is a cross-sectional view showing the structure of a first embodiment of the present invention. Figure 2 is a cross-sectional view showing the structure of a second embodiment of the present invention

100‧‧‧Device for detecting the boundary integrity of used nuclear fuel dry storage containers during operation

1‧‧‧Using nuclear fuel dry storage container external package

11‧‧‧air inlet

12‧‧‧ air outlet

13‧‧‧Structure ontology

131‧‧‧ accommodating space

14‧‧‧Top cover

2‧‧‧Used nuclear fuel dry storage container

3‧‧‧ collecting hood

31‧‧‧ collecting hood body

32‧‧‧Sampling line

4‧‧‧Gas sampling and analysis equipment

41‧‧‧ extraction or sampling unit

42‧‧‧Analysis unit

5‧‧‧ gap area

6‧‧‧Store floor substrate

Claims (10)

The device for detecting the boundary integrity of a spent nuclear fuel dry storage container during operation comprises: a used nuclear fuel dry storage container outer package, comprising at least one air inlet, one air outlet, one structural body and one The top cover is configured, and the structure body has an accommodating space, the accommodating space is connected to the air inlet and the air outlet; a used nuclear fuel dry storage container is placed on the used nuclear fuel The dry storage container outer package constitutes a used nuclear fuel dry storage system, and the used nuclear fuel dry storage container outer package and the used nuclear fuel dry storage container have a gap region; an external convection blocking device And combining the outer package of the used nuclear fuel dry storage container, the external convection blocking device comprising at least a body unit and a sampling unit for using the used nuclear fuel dry storage system or the gap region thereof with the natural Environmental isolation defines an isolation space and extracts or samples the gas in the isolated space; The sampling and analysis device is coupled to the external convection blocking device for detecting a helium leak rate, a helium gas concentration, or a radioactive gas concentration in the isolated space as a judgment of the sealed boundary integrity of the used nuclear fuel dry storage container The basis. The apparatus for detecting boundary integrity of a used nuclear fuel dry storage container during operation during the operation of the first aspect of the patent application, wherein the external convection resistance device is a gas collection cover, and the body unit is a gas collection cover body. And the sampling unit is a sampling pipeline, and the collecting hood is installed outside the outer package of the used nuclear fuel dry storage container, and is separated from the outer package of the used nuclear fuel dry storage container by a distance, and the set The insulating space is formed between the hood, the structural body, and the top cover. The apparatus for detecting the boundary integrity of a used nuclear fuel dry storage container during operation during the operation described in claim 2, wherein the lower end of the hood body is in contact with the storage floor substrate. A device for detecting boundary integrity of a spent nuclear fuel dry storage container during operation during the operation of claim 2, wherein the gas collection cover is completely covered with a spent nuclear fuel dry storage system and can be isolated A manifestation of the form of contact between the nuclear fuel dry storage system and the natural environment. A device for detecting the boundary integrity of a used nuclear fuel dry storage container during operation during the operation described in item 2 of the patent application scope, wherein the gas collection cover is completely packageable except for the bottom of the spent nuclear fuel dry storage system The use of the nuclear fuel dry storage system and the ability to isolate the use of the spent nuclear fuel dry storage system in contact with the natural environment. The device for detecting the boundary integrity of a spent nuclear fuel dry storage container during operation during the operation described in item 2 of the patent application scope, wherein the sampling line is in the form of an opening and closing function. The device for detecting boundary integrity of a used nuclear fuel dry storage container during operation during the operation described in claim 1 wherein the external convection blocking device is a cover plate, and the body unit is a cover body, and The sampling unit is a sampling joint, and the cover is installed and covered on the air inlet and the air outlet of the outer package of the used nuclear fuel dry storage container, and between the cover, the air inlet and the air outlet Form this isolation space. A device for detecting boundary integrity of a used nuclear fuel dry storage container during operation during the operation of claim 7 wherein the cover is partially covered with a spent nuclear fuel dry storage system and can be isolated The form of contact between the gap region of the nuclear fuel dry storage system and the natural environment. The apparatus for detecting the boundary integrity of a used nuclear fuel dry storage container during operation during the operation described in claim 7 of the patent application, wherein the sampling joint is in the form of an opening and closing function. A device for detecting boundary integrity of a spent nuclear fuel dry storage container during operation during the operation of claim 1 wherein the used nuclear fuel dry storage container is disposed outside the used nuclear fuel dry storage container The structure of the package is in the housing space of the body.