Simplified economical ventilated metal storage system

Abstract

Disclosed are various embodiments of a simplified economical ventilated metal storage system (SEVMSS) that can load and store hazardous radioactive spent nuclear fuel in a contaminated pool in a metal can and then place it in a passively ventilated metal package on a dry storage mat without the need to use a transfer barrel. The embodiment uses an insertion ring and a basin cup at the top and bottom of the package, respectively, to seal the annular space of the package when the package is located in the pool. After the package cools and is removed from the pool, the insert ring is replaced with the vent cover and the basin cup is removed. The package with the can is then placed on a dry storage mat with a shock-resistant stabilizing ring attached to the bottom thereof, or in an embedded opening of a ventilated storage mat.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of co-pending U.S. Provisional Patent Application No. 63 / 647,737, filed May 15, 2024, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] Embodiments of this disclosure generally involve loading hazardous spent radioactive nuclear fuel from a contaminated pool into a container and placing the container in a ventilated package on a dry storage pad, without using a transfer drum. Background Technology

[0004] In commercial nuclear power plants, spent nuclear fuel is typically stored in deep-water reservoirs (often called spent fuel pools) within the plant. When these spent fuel pools reach their spent fuel capacity limits, or when the nuclear power plant completely removes spent fuel from the pools at the end of its facility life, the fuel is transferred to metal containers with final sealing caps. After being loaded with spent fuel or radioactive waste, these metal containers are welded or otherwise sealed and sealed within the plant.

[0005] U.S. Patent No. 8,630,384 illustrates and describes an example design of a canister, which is incorporated herein by reference. This design comprises a basket having multiple internal parallel, elongated rectangular tubes for receiving spent nuclear fuel.

[0006] Transfer containers are individual containers typically used to remove tanks from contaminated pools. Examples of transfer containers are illustrated and described in commonly allocated U.S. Patent Nos. 11,728,058 and 10,032,533, which are incorporated herein by reference. Transfer containers are generally costly and require significant time and manpower to operate and ensure the safe transfer of fuel.

[0007] The sealed container is removed from the transfer container and placed into a ventilated storage package (typically composed of steel and concrete layers), which serves as an outer shell providing mechanical protection, passive heat dissipation, and additional radiation shielding for the internal metal container containing the radioactive material. Commonly allocated U.S. Patent No. 11,676,736 illustrates and describes an example of a ventilated storage package made entirely of steel, which is incorporated herein by reference. The ventilated storage package containing the welded metal container storing the radioactive material is then placed in a designated safe location outside the nuclear power plant structure, but within owner-controlled property to ensure proper control and monitoring of the ventilated storage package containing the metal container. Summary of the Invention

[0008] Disclosed are various embodiments of a simplified economical ventilated metal storage system (SEVMSS) capable of loading and storing hazardous spent radioactive nuclear fuel from a contaminated pool in metal canisters, which are then placed in a passively ventilated metal package on a dry storage pad, eliminating the need for transfer drums and saving significant time, cost, and human resources. This embodiment uses metal insert rings at the top and bottom of the package, and a metal basin cup at the bottom, to seal the annular space of the package while it is in the pool. After the package is removed from the pool, the insert rings are replaced with ventilated caps, and the basin cup is removed. The package with the canisters is then placed on a dry storage pad with shock-absorbing stabilizing rings attached to its bottom, or in an embedded opening in the ventilated storage pad.

[0009] One embodiment is a method. The method can be broadly summarized as follows: providing a metal package having an elongated cylindrical body extending between a top and a bottom, the body defining an internal annular space, the bottom having at least one air inlet vent for allowing airflow into the annular space; providing a metal can having an elongated cylindrical body extending between a top and a bottom, the body defining an internal space designed to receive hazardous spent radioactive nuclear fuel; placing the can in the annular space of the package; attaching a basin to the bottom of the package to seal at least one air inlet vent and the bottom of the annular space of the package; installing an insert ring between the top of the package and the top of the can to seal the top of the annular space of the package; placing the package in a pool contaminated with hazardous spent radioactive nuclear fuel; filling the can with fuel; attaching a sealing cap to the can to seal the fuel inside the can; removing the package from the pool; removing the insert ring; installing a vented cover having at least one exhaust vent to allow airflow from the annular space; and removing the package from the basin to provide passively ventilated packaging for dry storage of the can.

[0010] Another embodiment is a fuel loading device that enables the loading of hazardous radioactive spent nuclear fuel into a container, with the container and packaging assembly located within a pool. The device includes a metal package having an elongated cylindrical body extending between a top and a bottom. This body defines an internal annular space. The bottom end has at least one air inlet vent for allowing airflow into the annular space.

[0011] The device also includes a metal can with an elongated cylindrical body extending between its top and bottom. The can is located within a packaging annular space. The can defines the internal space containing hazardous radioactive spent nuclear fuel.

[0012] The sealing cap is located at the top of the tank to seal the fuel inside.

[0013] A removable basin is attached to the bottom of the packaging. The basin seals at least one air inlet vent and the bottom of the packaging's annular space.

[0014] There is a removable insert ring between the top of the packaging and the top of the can. The insert ring seals the top of the annular space of the packaging.

[0015] Other embodiments, apparatuses, systems, methods, features, and advantages of the present invention will become apparent to those skilled in the art upon studying the following drawings and detailed description. All such additional embodiments, apparatuses, methods, features, and advantages are included in this disclosure, fall within the scope of the invention, and are protected by the appended claims. Attached Figure Description

[0016] Many aspects of this disclosure can be better understood with reference to the accompanying drawings. The components in the drawings are not necessarily drawn to scale, but the focus is on clearly illustrating the principles of this disclosure.

[0017] Figure 1A and Figure 1B A first embodiment of a passively ventilated metal package is shown, which contains a metal canister containing hazardous radioactive spent nuclear fuel and is designed with shock-resistant stabilizing rings to allow the package to be placed on a flat, dry storage mat.

[0018] Figure 2 The shock-absorbing stabilizing ring that can be attached to the bottom of the packaging shown in Figure 1 is illustrated.

[0019] Figure 3 A second embodiment of a passively ventilated metal package is shown, which contains a metal canister containing hazardous radioactive spent nuclear fuel and is designed to be placed in an embedded opening in a ventilated dry storage pad.

[0020] Figure 4 Figure 1 and Figure 2 The packaging does not include a can or a vent cap.

[0021] Figure 5 The jar shown in Figure 1 is illustrated.

[0022] Figure 6 The diagram shows an in-pool configuration with an installed basin and an installed insert ring, both of which seal the elongated annular area between the package and the can, and isolate the elongated annular area from the contaminated pool water.

[0023] Figure 7 Figure 1 and Figure 2 The ventilation cover in the middle.

[0024] Figures 8A to 8D The basin cup and the internal seal associated with the basin cup are shown.

[0025] Figures 9A to 9D The insert ring, along with the internal and external seals associated with it, is shown.

[0026] Figure 10 These are embodiments of the methods according to this disclosure.

[0027] Figure 11 SEVMSS is shown in a facility with a nuclear reactor (e.g., but not limited to, a small modular reactor (SMR)). Detailed Implementation

[0028] What is disclosed are various embodiments of a simplified economical ventilated metal storage system (SEVMSS) that can load and store hazardous radioactive spent nuclear fuel in contaminated pools in metal containers, which are then placed in passively ventilated metal packs on dry storage pads, without the need for transfer drums, thus saving significant time, cost, and human resources.

[0029] More specifically, Figure 1 illustrates a first embodiment of SEVMSS, which has a package 10 ( Figure 4 Package 10 contains a variable-capacity metal container 11 containing hazardous radioactive spent nuclear fuel. Figure 5 ), and was designed with Figure 2 The shock-absorbing stabilizing ring 12 shown allows the package 10 to be placed on a flat, dry storage pad (not shown). The diameter and height of the variable-capacity tank 11 can be varied to accommodate nuclear materials specific to nuclear reactor facilities. Furthermore, the dimensions of the package 10 can be adjusted based on the dimensions of the tank 11.

[0030] The shock-absorbing stabilizing ring 12 has multiple upright threaded studs 14, enabling the ring 12 to be attached to the bottom of the package 10. A removable vent cap 16 is secured to the top of the package 10. Figure 1 and Figure 2 The arrows in the diagram illustrate passive cooling, where airflow enters through the bottom air inlet 13, passes through the annular space 15 of the package 10, and then flows out from the top air outlet 17 of the package 10.

[0031] Figure 3 A second embodiment of the SEVMSS is shown, which has a package 10 capable of containing a metal canister 11 containing hazardous radioactive spent nuclear fuel and is designed to be placed (without a stabilizing ring 12) in an embedded opening in a ventilated dry storage pad. An example of a usable ventilated dry storage pad is described in commonly allocated U.S. Application 18 / 429,907, filed February 1, 2024, which is incorporated herein by reference. The dry storage pad described in U.S. Application 18 / 429,907 features a triangular storage array to increase the density of nuclear material, thereby configuring the storage of nuclear material with maximum space efficiency, which is useful in situations where storage space is limited.

[0032] In a preferred embodiment, the sidewalls of the package 10 have at least three layers: a first forged steel inner layer, a second steel layer serving as a neutron shield, and a third rolled steel outer layer for absorbing gamma rays. Examples of this sidewall configuration and suitable canisters 11 are described in commonly assigned U.S. Patent No. 11,676,736, which is incorporated herein by reference.

[0033] like Figure 6 As shown, in the preferred embodiment, insert rings 22 and basins 24 (preferably made of steel) are used at the top and bottom of the packaging 10, respectively, thereby sealing the annular space of the packaging 10 when it is in the pool, i.e., isolating the annular space 15 from the contaminated pool water. In practice, Figure 6 The soaking and treatment configuration, or in-pool device 43, is shown.

[0034] In addition, such as Figures 8A to 8D Specifically, the basin cup 24 has a flat bottom 36 and upright cylindrical sidewalls 38, the flat bottom 36 having a circular outer edge. The basin cup 24 also has at least one inflatable seal 42 applicable to the inner side of the sidewalls 38. The basin cup 24 is attached to the package 10 by a plurality of upwardly extending tabs 37, each upwardly extending tab 37 having a hole through which fasteners such as bolts can pass. The aforementioned seal 42 helps prevent contaminants from entering the annular space of the package.

[0035] like Figures 9A to 9D Specifically, the insert ring 22 has a body 25, which is shaped as a ring or an upright cylindrical sidewall, as shown. The body 25 has a plurality of outwardly and radially extending tabs 26, each tab 26 having a hole 28. Suitable fasteners (such as bolts) can pass through the holes 28. The insert ring 22 also has a plurality of inflatable seals 32, 34, preferably at least one circular seal 32 on the inner side and at least one circular seal 34 on the outer side. The tabs 26 allow the insert ring 22 to be moved with suitable tools and ensure effective restraint of the package 10. The aforementioned seals 32, 34 help prevent contaminants from entering the annular space of the package.

[0036] After removing package 10 from the pool, remove insert ring 22 and install it on top of the package. Figure 7 The ventilated cover 16 is shown, and the basin cup 24 is removed. In a preferred embodiment, the ventilated cover 16 includes a centrally located single instrument mounting position 46 for thermal performance monitoring. The package 10 with the can is then placed on the dry storage pad, with a shock-absorbing stabilizing ring 12 attached to the bottom of the package 10, or the package 10 is placed in an embedded opening in the ventilated storage pad. As previously described, a suitable example of a ventilated dry storage pad is described in U.S. Patent Application No. 18 / 429,907, filed February 1, 2024, which is incorporated herein by reference.

[0037] like Figure 10 As shown, this disclosure provides an embodiment of method 50, which includes the following operations.

[0038] The metal package 10 has an elongated cylindrical body extending between its top and bottom ends. This body defines an annular space 15 within the elongated cylinder. The bottom end has at least one air inlet vent 13 for allowing airflow into the annular space 15.

[0039] Metal container 11 has an elongated cylindrical body extending between its top and bottom. At this point, the bottom of container 11 is closed, but its top is open. This body defines an internal space designed to receive hazardous spent radioactive nuclear fuel.

[0040] The can 11 is placed in the packaging annular space 15 associated with the packaging 10.

[0041] As shown in frame 51, the basin cup 24 is attached to the bottom of the package 10 to seal at least one air inlet vent 13 and the bottom of the package annular space 15.

[0042] As shown in box 52, an insert ring 22 is installed between the top of the package 10 and the top of the can 11 to seal the top of the package annular space 15 while leaving the top of the can 11 open.

[0043] As described in box 53, package 10 is placed in a pool contaminated with hazardous spent radioactive nuclear fuel. Preferably, package 10 has multiple lifting trunnions 44 to allow a lifting frame to lift, move, and lower package 10 as needed.

[0044] As shown in box 54, spent fuel is loaded into open tank 11.

[0045] According to frame 55, a circular, generally flat metal closure 19 is attached to tank 11 to seal fuel within tank 11. The circular metal closure 19 is attached to tank 11 in the pool. More specifically, after satisfactory verification of the contents of the tank (fuel and non-fuel hardware serial numbers), the closure 19 is lowered into position. The closure 19 can be installed via slings and associated rigging hardware, or it can be suspended from a lifting yoke.

[0046] Next, as shown in box 56, remove package 10 from the pool.

[0047] After removing package 10 from the pool, and before removing insert ring 22, weld cap 19 to tank 11 to seal tank 11. Water is drained from tank 11, which is then filled with an inert gas, such as helium. The tank cap includes two openings 44 and 46: one serves as a vent, and the other contains a threaded drain pipe to facilitate drainage, drying, and inert gas backfilling. After the inert gas backfilling is complete, these openings 44 and 46 are sealed again with a welded cap.

[0048] As shown in box 57, then remove the insertion ring 22.

[0049] A vent 16 is mounted on the top of the package 10, which has at least one air outlet 17, but preferably four, so that airflow can exit from the annular space 15, as shown in box 58.

[0050] Finally, at frame 59, the package 10 is removed from the basin cup 24 to provide passively ventilated package 10 for dry storage in can 11.

[0051] In this embodiment, after removing the basin cup 24, a shock-absorbing stabilizing ring 12 can be attached to the bottom of the package 10. Figure 2 Then the ventilated pack 10 can be placed and secured to the storage pad together with the shock-absorbing stabilizing ring 12. In another embodiment, after removing the basin cup 24, the ventilated pack 10 is placed on the recessed opening of the ventilated storage pad.

[0052] The above method can be used Figure 6 The pool-in-the-pool device 43 is implemented, which has a package 10 including a can 11, a basin 24 and an insertion ring 22.

[0053] Furthermore, due to the small size of package 10, SEVMSS and the aforementioned methods can be implemented in facility 60 with small modular reactors (SMRs), such as... Figure 11 As shown.

[0054] Finally, it should be emphasized that the above embodiments of the present invention are merely examples of possible, non-limiting implementations, and are only proposed to clearly understand the principles of the present invention. Many variations and modifications can be made to the above embodiments without departing from the spirit and principles of the present invention. All such modifications and variations are intended to be included within the scope of this disclosure and the present invention.

Claims

1. A method for removing hazardous radioactive spent nuclear fuel from a pool and then drying and storing it in a container within a ventilated package, the method comprising the following steps: A metal package is provided having an elongated cylindrical body extending between a top and a bottom, the body defining an internal annular space, the bottom having at least one air intake vent for allowing airflow into the annular space. A metal can is provided having an elongated cylindrical body extending between a top and a bottom, the body defining an internal space designed to receive hazardous radioactive spent nuclear fuel; Place the can in the annular space of the packaging; A basin cup is attached to the bottom of the packaging to seal the at least one air inlet vent and the bottom of the packaging annular space; An insert ring is installed between the top of the packaging and the top of the can to seal the top of the annular space of the packaging; The package was placed in a pool contaminated with the dangerous spent radioactive nuclear fuel. The fuel is loaded into the tank; A sealing cap is attached to the can to seal the fuel inside the can; Remove the package from the pool; Remove the insertion ring; Install a ventilation cover, which has at least one air outlet to allow airflow to exit from the annular space; as well as The packaging is removed from the basin to provide passively ventilated packaging for dry storage in the can.

2. The method according to claim 1, wherein, The basin cup has an inflatable inner circle seal, and the method further includes the following steps: inflating the basin cup seal to seal the at least one air inlet vent and the bottom of the packaging annular space.

3. The method according to claim 1, wherein, The insertion ring has an inflatable inner circle seal and an inflatable outer circle seal, and further includes the step of inflating the insertion ring seal to seal the top of the packaging annular space.

4. The method according to claim 1, further comprising the following steps: Demineralized water is introduced into the annular space of the package before it is placed into the pool.

5. The method according to claim 1, further comprising the following step: After the package is removed from the pool, and before the insert ring is removed: Weld the sealing cap of the can to seal the can; Water is drained from the canister through the port on the lid, and inert helium is introduced into the canister; and A cover is welded onto the port.

6. The method according to claim 1, further comprising the following step: After the package is removed from the pool, and before the insert ring is removed: Vent the seals of the basin cup and the insertion ring; and Drain the water from the annular space of the packaging.

7. The method according to claim 1, wherein, The packaging has at least one neutron-absorbing layer and at least one gamma-ray-absorbing layer.

8. The method according to claim 1, wherein, The package has at least one lifting trunnion, wherein the steps of placing the package in the pool and removing the package from the pool are performed by using the at least one lifting trunnion.

9. The method according to claim 1, wherein, The method is performed in a facility with a small modular reactor (SMR).

10. The method according to claim 1, wherein, The basin cup includes a flat bottom and upright cylindrical sidewalls, the flat bottom having a circular outer edge.

11. The method according to claim 1, further comprising the following step: After removing the basin / cup: An anti-vibration stabilizing ring is attached to the bottom of the packaging; and Place the ventilated package together with the shock-absorbing ring on the storage pad.

12. The method according to claim 1, further comprising the following step: After removing the basin cup, place the ventilated pack on the recessed opening of the ventilated storage pad.

13. A method for removing hazardous radioactive spent nuclear fuel from a pool and then drying and storing it in a container within a ventilated package, the method comprising the steps of: A metal package is provided having an elongated cylindrical body extending between a top and a bottom, the body defining an internal annular space, the bottom having at least one air intake vent for allowing airflow into the annular space. A metal can is provided having an elongated cylindrical body extending between a top and a bottom, the body defining an internal space designed to receive hazardous radioactive spent nuclear fuel; Place the can in the annular space of the packaging; A basin cup is attached to the bottom of the packaging, the basin cup having an inflatable inner circle seal; Inflate the basin-cup seal to seal the at least one air inlet vent and the bottom of the packaging annular space; An insert ring is installed between the top of the packaging and the top of the can, the insert ring having an inflatable inner circle seal and an inflatable outer circle seal; Inflate the insert ring seal to seal the top of the annular space of the package; Demineralized water is introduced into the annular space of the packaging; The package was placed in a pool contaminated with the dangerous spent radioactive nuclear fuel. The fuel is loaded into the tank; A sealing cap is attached to the can to seal the fuel inside the can; Remove the package from the pool; Seal the welded cap to the tank; The water in the can is drained through the port on the lid, and inert helium is introduced into the can. A cover is welded onto the port. Release the air from the seals of the basin cup and the insertion ring; Drain the water from the annular space of the packaging; Remove the insertion ring; Install a ventilation cover, which has at least one air outlet to allow airflow to exit from the annular space; as well as The packaging is removed from the basin to provide ventilated packaging for dry storage in the can.

14. The method according to claim 13, wherein, The packaging has at least one neutron-absorbing layer and at least one gamma-ray-absorbing layer.

15. The method according to claim 13, wherein, The package has at least one lifting trunnion, wherein the steps of placing the package in the pool and removing the package from the pool are performed by using the at least one lifting trunnion.

16. The method according to claim 13, wherein, The method is performed in a facility with a small modular reactor (SMR).

17. The method according to claim 13, wherein, The basin cup includes a flat bottom and upright cylindrical sidewalls, the flat bottom having a circular outer edge.

18. The method of claim 13, further comprising the step of: After removing the basin / cup: An anti-vibration stabilizing ring is attached to the bottom of the packaging; and Place the ventilated package together with the shock-absorbing ring on the storage pad.

19. The method of claim 13, further comprising the step of: After removing the basin cup, place the ventilated pack on the recessed opening of the ventilated storage pad.

20. A fuel loading device located in a pool contaminated with hazardous spent radioactive nuclear fuel, the device comprising: A metal package having an elongated cylindrical body extending between a top and a bottom, the body defining an internal annular space, the bottom having at least one air intake vent for allowing airflow into the annular space. A metal can having an elongated cylindrical body extending between a top and a closed bottom, the can being located within a packaging annular space, the can defining an internal space containing hazardous radioactive spent nuclear fuel; A sealing cap, located at the top of the can, to seal the fuel inside the can; A removable basin cup is attached to the bottom of the packaging, and the basin cup seals the bottom of the at least one air inlet vent and the annular space of the packaging. as well as A removable insert ring is located between the top of the package and the top of the can, and the insert ring seals the top of the annular space of the package.

21. The apparatus according to claim 20, wherein, The basin cup has an inflatable inner circle seal to seal the at least one air inlet vent and the bottom of the packaging annular space.

22. The apparatus according to claim 20, wherein, The insertion ring has an inflatable inner circle seal and an inflatable outer circle seal to seal the top of the packaging annular space.

23. The apparatus of claim 20, further comprising demineralized water in the annular space of the packaging.

24. The apparatus according to claim 20, wherein, The package has at least one neutron layer that absorbs fuel emissions and at least one gamma-ray layer that absorbs fuel emissions.

25. The apparatus according to claim 20, wherein, The packaging has multiple lifting trunnions capable of moving the packaging.

26. A facility having a small modular reactor (SMR) and the apparatus of claim 20 located in a pool.

27. The apparatus according to claim 20, wherein, The basin cup includes a flat bottom and upright cylindrical sidewalls, the flat bottom having a circular outer edge, and the flat bottom is placed on the bottom associated with the pool.

28. The apparatus according to claim 20, wherein, The insertion ring includes a plurality of outwardly extending tabs capable of securing the ring.

29. A method for transferring fuel to a ventilated and dry storage tank, comprising the following steps: Remove the packaging as described in claim 20 from the pool; Seal the welded cap to the tank; Water is drained from the tank through the port on the sealed cover, and inert helium is introduced into the tank. A cover is welded onto the port. Release the air from the seals of the basin cup and the insertion ring; Drain the water from the annular space of the packaging; Remove the insertion ring; Install a ventilation cover, which has at least one air outlet to allow airflow to exit from the annular space; as well as Remove the basin from the packaging to provide a ventilated, dry storage package for dry storage of the can.

Images