Stopcock assembly for a reactor

Abstract

Embodiments of the present application relate to the technical field of nuclear reactors, and particularly relate to a plug assembly for a reactor. The reactor includes a reactor vessel, a core assembly disposed in the reactor vessel, the reactor vessel including a vessel opening, and a refueling machine. The plug assembly includes a first plug, a second plug, and a third plug. The first plug is rotatably disposed in the vessel opening of the reactor vessel, and the first plug is provided with an eccentric first through hole, the size of the first through hole being greater than the radius of the first plug. The second plug is disposed in the first through hole of the first plug and is rotatable relative to the first plug, and the second plug is provided with an eccentric second through hole. The third plug is disposed in the second through hole of the second plug and is rotatable relative to the second plug, and the third plug is provided with an eccentric third through hole. The refueling machine is disposed in the third through hole of the third plug. The plug assembly of the embodiments of the present application is beneficial to increase the moving range of the refueling machine and reduce the size of the first plug.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear reactors, in particular to a plug assembly for a reactor. BACKGROUND

[0002] This part only provides background information of the present application, and does not necessarily constitute the prior art.

[0003] In a fast reactor, the plug assembly is a main refueling equipment arranged on the reactor vessel, which can realize the positioning of the refueling machine and the core assembly, and cooperate with the refueling machine to complete the transfer of the internal components of the reactor vessel. At the same time, the plug assembly is installed on the reactor vessel as part of the pressure boundary of the reactor vessel, which plays a role in sealing the reactor vessel and preventing the leakage of radioactive argon gas and sodium aerosol.

[0004] At present, there are still many problems in the design of the plug assembly, which affects the economy of the reactor. SUMMARY

[0005] In the following, a brief summary of the present application is given to provide a basic understanding of some aspects of the present application. It should be understood that this summary is not an exhaustive overview of the present application. It is not intended to identify key or important parts of the present application, nor is it intended to limit the scope of the present application. Its purpose is only to give some concepts in a simplified form as a prelude to the more detailed description discussed later.

[0006] In view of the above technical problems, the embodiments of the present application provide a plug assembly for a reactor. The reactor can include a reactor vessel, a core assembly arranged in the reactor vessel, and the reactor vessel can include a vessel opening coaxial with the core assembly. The reactor can also include a refueling machine. The plug assembly can include a first plug, a second plug and a third plug. The first plug is rotatably arranged in the vessel opening of the reactor vessel, and the first plug is provided with an eccentric first through hole, and the size of the first through hole is greater than the radius of the first plug. The second plug is arranged in the first through hole of the first plug and can rotate relative to the first plug, and the second plug is provided with an eccentric second through hole. The third plug is arranged in the second through hole of the second plug and can rotate relative to the second plug, and the third plug is provided with an eccentric third through hole. The refueling machine is arranged in the third through hole of the third plug.

[0007] The plug assembly provided by the embodiments of the present application has the advantages that by arranging three plugs and making the size of the first through hole greater than the radius of the first plug, the movement range of the refueling machine is increased, and the size of the first plug is reduced by the rotation cooperation of the three plugs.

[0008] These and other advantages of the present application will become more apparent from the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0009] To further illustrate and describe the above and other advantages and features of the application, a particular implementation of the application will be described in further detail below by reference to the drawings. The drawings described are intended to be illustrative, and not restrictive, of the application, and are included to provide a description of exemplary embodiments of the application. Like reference numerals used in the figures refer to like elements throughout the figures and specification.

[0010] Figure 1 is a cross-sectional view of a plug assembly according to an embodiment of the application;

[0011] Figure 2 is a distribution view of three plugs;

[0012] Figure 3 is Figure 1 is a top view of a plug assembly of a control rod drive mechanism mounting nozzle shown in

[0013] Figure 4 is Figure 1 is a cross-sectional view of a first plug shown in

[0014] Figure 5 is Figure 4 is a top view of a first plug shown in

[0015] Figure 6 is Figure 1 is a cross-sectional view of a second plug shown in

[0016] Figure 7 is Figure 6 is a top view of a second plug shown in

[0017] Figure 8 is Figure 1 is a cross-sectional view of a third plug shown in

[0018] Figure 9 is Figure 8 is a top view of a third plug shown in

[0019] Figure 10 is Figure 1 is a partial enlarged view shown in

[0020] Figure 11 is Figure 1 is a partial enlarged view shown in

[0021] Figure 12 is Figure 10 is a partial enlarged view shown in, in which arrows indicate air flow direction;

[0022] Figure 13 isFigure 12 the arrow shows the direction of air flow;

[0023] Figure 14 is Figure 8 the third plug is shown in a partial enlarged view;

[0024] Figure 15 is Figure 6 the second plug is shown in a partial enlarged view.

[0025] It should be noted that the drawings are not necessarily drawn to scale, but are only shown in a schematic manner without affecting the understanding of the reader.

[0026] Explanation of reference signs:

[0027] 11, stack vessel; 111, vessel opening; 12, core assembly; 13, tie rod; 14, movable guide tube; 15, in-core shield;

[0028] 101, annular negative pressure air duct;

[0029] 20, first plug; 21, first dynamic sealing structure; 22, first body section; 221, upper shell; 2211, upper top plate; 2212, upper bottom plate; 2213, upper radial outer side plate; 2214, first through-hole upper surrounding plate; 222, lower shell; 2221, support plate; 2222, steel column; 223, screw rod; 23, first gamma shield section; 24, first connecting section; 241, reinforcing rib; 25, manhole plug; 251, plug body shield section; 253, plug body gamma shield layer; 254, connecting rod; 26, manhole passage; 27, first through-hole;

[0030] 201, first air duct; 2011, first air inlet;

[0031] 202, first bearing; 203, first gear ring; 204, first drive mechanism;

[0032] 30, second plug; 31, second dynamic sealing structure; 32, second body section; 321, second shell; 3211, second top plate; 3212, second bottom plate; 3213, second radial outer side plate; 3214, second through-hole surrounding plate; 33, second gamma shield section; 34, second connecting section; 35, control rod drive mechanism mounting pipe seat; 350, predetermined circumference; 351, first mounting plate; 360, second mounting plate; 36, control rod protection piece; 361, cylinder; 362, bottom head; 37, thermocouple mounting pipe seat; 38, lifting mechanism pipe seat; 39, second through-hole;

[0033] 301, second air duct; 3011, second air inlet;

[0034] 302, second bearing; 303, second ring gear; 304, second driving mechanism;

[0035] 40, third plug; 41, third dynamic sealing structure; 42, third body section; 421, third housing; 4211, third top plate; 4212, third bottom plate; 4213, third radial outer plate; 4214, third through-hole surrounding plate; 4215, fourth through-hole surrounding plate; 43, third gamma shielding section; 44, third connecting section; 45, third through-hole; 46, fourth through-hole; 47, fuel handling machine nozzle;

[0036] 401, third air duct; 4011, third air inlet;

[0037] 402, third bearing; 403, third ring gear; 404, third driving mechanism;

[0038] 51, thermal shielding layer; 52, neutron shielding layer;

[0039] 61, first sealing plate; 62, first support cylinder; 621, first support cylinder ventilation hole; 63, first air-cooling surrounding cylinder; 631, first air-cooling ventilation hole; 64, first annular plate; 65, first ventilation plate; 66, first sealing connecting part;

[0040] 71, second sealing plate; 72, second support cylinder; 721, second support cylinder ventilation hole; 73, second air-cooling surrounding cylinder; 731, second air-cooling ventilation hole; 74, second annular plate; 76, second sealing connecting part;

[0041] 81, third sealing plate; 82, third support cylinder; 83, third air-cooling surrounding cylinder; 831, third air-cooling ventilation hole; 84, third annular plate;

[0042] 91, first communication air duct; 92, second communication air duct; 93, third communication air duct; 94, sealing body; 95, fitting part; 96, heating assembly; 97, containing groove; 971, first groove; 972, second groove; 98, liquid metal. DETAILED DESCRIPTION

[0043] Exemplary embodiments of the present application will be described herein below with reference to the accompanying drawings. In the description, all features that are not described in detail of the actual embodiments have not been described in the specification for the sake of clarity and conciseness. It should be appreciated, however, that many implementation-specific decisions can have to be made in order to develop any such actual embodiments, to implement developer-specific goals, such as compliance with system- and business-related constraints, which will vary from one implementation to another. It should also be appreciated that, while the development work can be very complex and time-consuming, it would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

[0044] It should be noted that, in order not to obscure the application with unnecessary details, only the structures of the devices and / or the processing steps closely related to the scheme according to the application are shown in the drawings, and other details not closely related to the application are omitted.

[0045] It should be noted that, unless otherwise defined, technical or scientific terms used in the present application should be understood as their common meanings to those skilled in the art to which the present application pertains.

[0046] In the description of the embodiments of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly and specifically limited.

[0047] In the related art, the plug assembly includes a large plug and a small plug, the small plug is rotatably arranged on the large plug, the refueling machine is arranged on the small plug, and the refueling machine has a certain refueling range through the rotation of the large plug and the small plug. The inventors of the present application found that the plug assembly with the above structure usually has a large size of the large plug, which leads to a large size of the plug assembly as a whole, which is not conducive to improving the economy of the reactor.

[0048] Therefore, in order to solve the above technical problems, the embodiments of the present application provide a plug assembly for a reactor. Referring to Figures 1 to 3 , Figure 1 is a cross-sectional view of a plug assembly according to an embodiment of the present application, Figure 2 is a distribution diagram of three plugs, Figure 3 is a top view of a plug assembly omitting a control rod drive mechanism mounting nozzle, the reactor can include a reactor vessel 11, a core assembly 12 arranged in the reactor vessel 11, the reactor vessel 11 can include a vessel opening 111 coaxial with the core assembly 12, the reactor can further include a refueling machine, and the plug assembly can include a first plug 20, a second plug 30, and a third plug 40. The first plug 20 is rotatably arranged on the vessel opening 111 of the reactor vessel 11 of the reactor, the first plug 20 is provided with an eccentric first through hole 27, and the size of the first through hole 27 is greater than the radius of the first plug 20. The second plug 30 is arranged in the first through hole 27 of the first plug 20 and can rotate relative to the first plug 20, and the second plug 30 is provided with an eccentric second through hole 39. The third plug 40 is arranged in the second through hole 39 of the second plug 30 and can rotate relative to the second plug 30, and the third plug 40 is provided with an eccentric third through hole 45. The refueling machine is arranged in the third through hole 45 of the third plug 40.

[0049] The cock assembly provided by the embodiment of the present application is provided with three cocks, the size of the first through hole 27 is greater than the radius of the first cock 20, and the rotation of the three cocks is conducive to increasing the moving range of the refueling machine, reducing the size of the first cock 20, optimizing the arrangement space of the cock assembly, and improving the economy and refueling efficiency of the reactor.

[0050] Referring to Figure 2 In some embodiments, the sum of the distance between the center of the second through hole 39 and the center of the second cock 30 is equal to one half of the radius of the core assembly 12. It is easy to understand that the refueling machine rotates the third through hole 45 of the third cock 40 relative to the second cock 30, the second cock 30 rotates relative to the first cock 20, and the first cock 20 rotates relative to the container opening 111 of the container 11, so that the moving track of the refueling machine is affected by the eccentric through hole position of each cock. By such an arrangement, the refueling machine can move in a circular range with the center of the core assembly 12 as the center and the radius of the core assembly 12 as the radius, ensuring that the moving track of the refueling machine can completely cover the core assembly 12 under the premise that the size of the cock is as small as possible, thereby improving the space utilization and refueling efficiency of the cock assembly.

[0051] In some embodiments, the third cock 40 can also be provided with an eccentric fourth through hole 46 for placing a spare refueling machine or flow meter, thereby improving the maintenance efficiency and flexibility of the reactor.

[0052] In some embodiments, the fourth through hole 46 and the third through hole 45 are symmetrically distributed relative to the center of the third cock 40, the center of the fourth through hole 46, the center of the third through hole 45 and the center of the third cock 40 are collinear, so that the third cock 40 is compactly arranged.

[0053] In some embodiments, the reactor can also include a plurality of control rods and a plurality of control rod drive mechanisms connected with the control rods. Referring to Figure 2 and Figure 7 , Figure 7The top view of the second plug is shown. The second plug 30 can include a plurality of control rod drive mechanism mounting seats 35 for mounting a plurality of control rod drive mechanisms. The plurality of control rod drive mechanism mounting seats 35 are arranged in a predetermined circle 350, which can be in a position concentric with the first plug 20 by rotating the second plug 30 relative to the first plug 20. Since the second plug 30 can be rotated relative to the first plug 20, the first plug 20 can be rotated relative to the container opening 111, and the predetermined circle 350 where the control rod drive mechanism mounting seats 35 are located can be adjusted in position. When the second plug 30 is in the working position and is not rotated, the predetermined circle 350 is concentric with the first plug 20, and at this time, each control rod drive mechanism mounting seat 35 can be located directly above the core assembly 12. When refueling is required, after all the control rods are dropped, the second plug 30 is rotated to move the control rod drive mechanism mounting seats 35 out of the core assembly 12 to provide space for the refueling machine, thereby ensuring accurate positioning and effective control of the control rods and control rod drive mechanisms during normal operation of the reactor, and achieving flexible avoidance during the refueling process, improving the overall operation efficiency and safety of the reactor.

[0054] In some embodiments, referring to Figure 2 , the center of the second through hole 39 is collinear with the center of the first through hole 27 and the center of the first plug 20, which can ensure compact layout, reduce space waste and additional material requirements due to eccentric arrangement, thereby facilitating reduction of the size of the first plug 20 while ensuring the function of the plug, and improving space utilization.

[0055] In some embodiments, referring to Figure 1 , the plug assembly can further include a first dynamic sealing structure 21, a second dynamic sealing structure 31, and a third dynamic sealing structure 41. The first dynamic sealing structure 21 is used to seal the first plug 20 and the container opening 111 of the reactor vessel 11. The second dynamic sealing structure 31 is used to seal the second plug 30 and the first through hole 27 of the first plug 20. The third dynamic sealing structure 41 is used to seal the third plug 40 and the second through hole 39 of the second plug 30. The difference between the diameter of the first plug 20 and the diameter of the core assembly 12 is equal to the sum of the ring width of the first dynamic sealing structure 21, the ring width of the second dynamic sealing structure 31, and the ring width of the third dynamic sealing structure 41, thereby facilitating the movement trajectory of the refueling machine to completely cover the core assembly 12, while also ensuring the sealing performance of the opening of the reactor vessel 11, effectively preventing the leakage of radioactive substances.

[0056] In some embodiments, Figure 13is a partial enlarged view of the plug assembly, the first dynamic sealing structure 21 can include a sealing body 94, a matching piece 95 and a heating assembly 96. The sealing body 94 is connected with the periphery of the container opening 111 of the reactor vessel 11 at the radial outside of the sealing body 94, the sealing body 94 is arranged to form a containing groove 97, the containing groove 97 contains liquid metal 98 (for example, lead-bismuth alloy). The matching piece 95 is connected with the first plug 20, the matching piece 95 divides the containing groove 97 into a first groove 971 at the radial inside and a second groove 972 at the radial outside, the bottoms of the first groove 971 and the second groove 972 are communicated; the heating assembly 96 is arranged at the radial outside of the containing groove 97, and is used for heating the liquid metal 98 in the containing groove 97. When the first plug 20 does not rotate, the first plug 20 and the reactor vessel 11 are sealed by the solidified liquid metal; when the first plug 20 needs to rotate, the heating assembly 96 heats the liquid metal 98 in the containing groove 97, so that the liquid metal 98 is melted in liquid state, and the plug and the reactor vessel are dynamically sealed by the liquid metal.

[0057] In some embodiments, the second dynamic sealing structure 31 and the third dynamic sealing structure 41 can have the same structure as the first dynamic sealing structure 21.

[0058] Referring to Figure 2 In some embodiments, the distance between the center of the third through hole 45 of the third plug 40 and the center of the first plug 20 is equal to twice the distance between the center of the second plug 30 and the center of the first plug 20, so that when the refueling machine in the third through hole 45 rotates 180 degrees with the second plug 30, the refueling machine can cover the position of the center of the core assembly 12, thereby achieving effective refueling in the whole range of the core assembly 12.

[0059] Referring to Figure 4 , Figure 4 is a cross-sectional view of the first plug 20, in some embodiments, the first plug 20 can include a first body section 22, a first gamma shielding section 23 and a first connecting section 24, the first gamma shielding section 23 is connected with the first body section 22 through the first connecting section 24. The first body section 22 faces the container opening 111 of the reactor vessel 11, and the first connecting section 24 and the first gamma shielding section 23 enter the inside of the reactor vessel 11. It is easy to understand that part of the structure of the first plug 20 is located inside the reactor vessel 11 and is affected by the high temperature in the reactor, while the part of the structure located outside the reactor is in a normal temperature state, which causes a significant temperature difference of the first plug 20, thereby easily causing deformation. The embodiment divides the first plug 20 into multiple sections, which can effectively reduce the deformation of the first plug 20 caused by the temperature difference.

[0060] The first gamma shielding section 23 of the first plug 20 can enter the radial inside of the top of the in-core shield 15.

[0061] In some embodiments, the first body segment 22 can include a thermal shielding layer 51 and a neutron shielding layer 52 for reducing heat transfer and shielding in-core neutrons, respectively.

[0062] In some embodiments, the thermal shielding layer 51 can be a calcium silicate layer. In some embodiments, the neutron shielding layer 52 can be a graphite layer.

[0063] In some embodiments, the first body segment 22 can include an upper segment portion and a lower segment portion connected by a plurality of screws 223. The upper segment portion of the first body segment 22 can include an upper housing 221 and a plurality of layers of the neutron shielding layer 52 disposed in the upper housing 221. The upper housing 221 forms a sealed structure, and the upper housing 221 can include an upper top plate 2211, an upper bottom plate 2212, an upper radial outer side plate 2213, and a first through-hole upper surrounding plate 2214, which collectively enclose a sealed space in which the plurality of layers of the neutron shielding layer 52 are disposed.

[0064] The lower segment portion of the first body segment 22 can include a lower housing 222, a plurality of layers of the neutron shielding layer 52 disposed in the lower housing 222, and a plurality of layers of the thermal shielding layer 51. The lower housing 222 can include a lower top plate, a lower bottom plate, a lower radial outer side plate, and a first through-hole lower surrounding plate, which collectively enclose a sealed space in which the neutron shielding layer 52 and the thermal shielding layer 51 are alternately disposed, with the thermal shielding layer 51 being at the lowermost position. This embodiment divides the first body segment 22 into an upper segment portion and a lower segment portion. The upper segment portion is mainly used to ensure structural stability and shield neutrons. The lower segment portion is close to the reactor, has a high temperature, and has the neutron shielding layer 52 and the thermal shielding layer 51 alternately disposed with the thermal shielding layer 51 being at the lowermost position, which can effectively prevent thermal deformation and shield neutrons, and enhance the stability of the overall structure and each shielding material.

[0065] In addition, the upper housing 221 and the lower housing 222 are arranged as a sealed structure, which can also prevent radioactive substances from leaking.

[0066] In some embodiments, the lower segment portion can further include a plurality of layers of support plates 2221 (e.g., thin steel plates) for supporting the neutron shielding layer 52 and the thermal shielding layer 51. To enhance the support effect, the lower segment portion can further include a plurality of steel columns 2222 disposed between two adjacent layers of the support plates 2221. The bottom of the steel column 2222 can be fixed to the lower support plate 2221 by screwing, and the top of the steel column 2222 can abut against the upper support plate 2221 to support the upper support plate 2221, which facilitates installation and is also conducive to avoiding structural deformation caused by thermal expansion.

[0067] In some embodiments, the first connecting section 24 can be a steel cylinder structure, and the first gamma shielding section 23 is connected to the bottom end of the steel cylinder. The steel cylinder can effectively reduce the temperature of the first gamma shielding section 23, reduce the deformation of the first plug 20 due to temperature difference, and also play a heat shielding role.

[0068] In some embodiments, the first gamma shielding section 23 can be a multi-layer steel plate structure arranged at intervals, which can enhance the shielding effect of gamma rays and improve the safety of the reactor operation.

[0069] In some embodiments, the inner wall of the steel cylinder can be provided with a plurality of inclined reinforcing ribs 241, which can enhance the structural strength of the steel cylinder and prevent the steel cylinder from deforming due to high temperature.

[0070] Referring to Figure 4 and Figure 5 , Figure 5 is a top view of the first plug 20. In some embodiments, the first plug 20 can also form a manhole passage 26 for operators to pass through and a manhole plug 25 for closing the manhole passage 26. The manhole passage 26 extends downward through the first body section 22 and the first gamma shielding section 23. The manhole passage 26 is located radially inside the first connecting section 24.

[0071] The manhole plug 25 can include a plug body shielding section 251, a connecting rod 254, and a plug body gamma shielding layer 253 connected to the plug body shielding section 251 through the connecting rod 254. The plug body shielding section 251, the connecting rod 254, and the plug body gamma shielding layer 253 respectively face the first body section 22, the first connecting section 24, and the first gamma shielding section 23. In this embodiment, the manhole passage 26 is formed in the first plug 20, which can facilitate the operators to enter the inside of the reactor vessel 11 for maintenance and repair. After the operators complete the maintenance or repair work, the manhole plug 25 can be used to close the manhole passage 26, ensuring the overall sealing of the first plug 20. At the same time, the manhole plug 25 is also provided with multiple layers of shielding, ensuring the safety of the reactor operation.

[0072] In some embodiments, the plug body gamma shielding layer 253 can be a cylindrical steel block for shielding gamma rays and cooling high-temperature gas escaping from the reactor. The structure of the plug body shielding section 251 can be the same as that of the first body section 22.

[0073] Referring to Figure 6 and Figure 7 and Figure 15 , Figure 6 is a cross-sectional view of the second plug 30, Figure 7 is Figure 6 a top view of the second plug 30 shown in FIG. 8; Figure 15 is Figure 6A partial enlarged view of the second plug 30 is shown. In some embodiments, the second plug 30 can further include a second body segment 32, a second gamma shielding segment 33, and a second connecting segment 34. The second gamma shielding segment 33 is connected to the second body segment 32 through the second connecting segment 34. The embodiment divides the second plug 30 into multiple segments, which can effectively reduce deformation of the second plug 30 due to temperature difference.

[0074] In some embodiments, the plurality of control rod drive mechanism mounting nozzles 35 can be arranged on the second body segment 32. The second plug 30 can further include a control rod protection member 36. The control rod protection member 36 is connected to the second connecting segment 34 at the lower end of the second connecting segment 34. The control rods extend downward from the radially inner side of the control rod protection member 36. The control rod protection member 36 can effectively prevent the control rods from being impacted by the in-core coolant, thereby ensuring stability of the control rods during operation of the reactor.

[0075] In some embodiments, the control rod protection member 36 can include a cylinder 361 and a bottom head 362, and the bottom head 362 is provided with a through hole for each control rod, so that the control rods can be protected in the cylinder 361 and avoid being impacted by liquid metal, and the control rods can also fall through the through hole of the bottom head 362 during operation of the reactor, ensuring safety of the reactor.

[0076] In some embodiments, there is a minimum distance between the third through hole 45 and the control rod protection member 36. During rotation of the refueling machine, the refueling machine always maintains a certain distance from the control rod protection member 36, thereby avoiding affecting operation of the refueling machine due to interference of the control rod protection member 36. The minimum distance can be determined according to the size of the refueling machine and the outer dimensions of the control rod protection member 36, to ensure that the two do not interfere with each other and do not affect operation of the refueling machine. The minimum distance increases, and the overall size of the plug assembly also increases, which is not conducive to economy and plug arrangement. In some embodiments, the minimum distance can be greater than 127 mm, for example.

[0077] In some embodiments, the reactor can further include a plurality of thermocouples, and the second plug 30 can further include a plurality of thermocouple mounting nozzles 37 for mounting the plurality of thermocouples. The plurality of thermocouple mounting nozzles 37 can be arranged on the second body segment 32. The embodiment can achieve stable mounting of the thermocouples by arranging the plurality of thermocouple mounting nozzles 37 on the body segment of the second plug 30, which facilitates monitoring of the temperature in the reactor, thereby improving safety of operation of the reactor.

[0078] In some embodiments, the reactor can further comprise a plurality of movable guide tube lifting mechanisms, the second plug 30 can comprise a plurality of lifting mechanism sockets 38, the reactor can comprise a plurality of pull rods 13 and a plurality of movable guide tubes 14, and the lifting mechanism sockets 38 are used to install the plurality of movable guide tube lifting mechanisms. The plurality of lifting mechanism sockets 38 can be arranged on the second body section 32. The movable guide tube lifting mechanisms are used to drive the pull rods 13 and the movable guide tubes 14 to perform lifting movement, thereby driving the control rods to lift.

[0079] In some embodiments, referring to Figure 6 , the second body section 32 can comprise a thermal shielding layer 51 and a neutron shielding layer 52, which are respectively used to reduce heat transfer and shield in-core neutrons.

[0080] In some embodiments, the second body section 32 can comprise a second shell 321, a plurality of layers of neutron shielding layers 52 and a plurality of layers of thermal shielding layers 51 arranged in the second shell 321. The second shell 321 can comprise a second top plate 3211, a second bottom plate 3212, a second radial outer plate 3213, and a second through-hole surrounding plate 3214, which collectively enclose a sealed space in which the neutron shielding layers 52 and the thermal shielding layers 51 are arranged.

[0081] The upper part of the sealed space can be provided with a plurality of layers of neutron shielding layers 52, and the lower part of the sealed space can be alternately provided with neutron shielding layers 52 and thermal shielding layers 51, with the lowermost being a thermal shielding layer 51. This embodiment reduces heat transfer and shields in-core neutrons by arranging a plurality of layers of shielding layers in the second body section 32.

[0082] In some embodiments, the second connecting section 34 can be in the form of a steel cylinder, and the second gamma shielding section 33 is connected to the bottom end of the steel cylinder. The steel cylinder can effectively reduce the temperature of the second gamma shielding section 33, thereby playing a thermal shielding role.

[0083] In some embodiments, the second body section 32 can comprise a first mounting plate 351, and the second connecting section 34 is connected to the first mounting plate 351. A plurality of holes are formed in the first mounting plate 351, which are used to suspend the guide tubes of the control rod drive mechanism, the guide tubes of the thermocouples, and the guide tubes of the control rod drive mechanism.

[0084] In some embodiments, the second gamma shielding section 33 can comprise a plurality of layers of steel plates, which can enhance the shielding effect of gamma rays and improve the safety of the reactor operation.

[0085] In some embodiments, the second plug 30 can comprise a second mounting plate 360, and the control rod protection member 36 is connected to the second mounting plate 360.

[0086] Referring to Figure 8 and Figure 9 and Figure 14 , Figure 8is a cross-sectional view of the third plug 40, Figure 9 is a top view of the third plug 40, Figure 14 is Figure 8 is a partial enlarged view of the third plug 40. In some embodiments, the third plug 40 can include a third body segment 42, a third gamma shielding segment 43, and a third connecting segment 44, the third gamma shielding segment 43 being connected to the third body segment 42 through the third connecting segment 44. The embodiment divides the third plug 40 into multiple segments, which can effectively reduce the deformation of the third plug 40 caused by temperature difference.

[0087] In some embodiments, the third body segment 42 can include a thermal shielding layer 51 and a neutron shielding layer 52, respectively used for reducing heat transfer and shielding in-core neutrons.

[0088] In some embodiments, the third body segment 42 can include a third shell 421, a multilayer neutron shielding layer 52, and a multilayer thermal shielding layer 51 arranged in the third shell 421. The third shell 421 can include a third top plate 4211, a third bottom plate 4212, a third radial outer plate 4213, a third through-hole surrounding plate 4214, and a fourth through-hole surrounding plate 4215, which collectively enclose a sealed space in which the neutron shielding layer 52 and the thermal shielding layer 51 are arranged.

[0089] The upper part of the sealed space of the third body segment 42 can be provided with a multilayer neutron shielding layer 52, and the lower part can be alternately provided with a neutron shielding layer 52 and a thermal shielding layer 51, with the lowermost being a thermal shielding layer 51, thereby effectively insulating and shielding neutrons.

[0090] In some embodiments, the third plug 40 further includes a refueling machine pipe seat 47 arranged in the third body segment 42 for mounting a refueling machine.

[0091] In some embodiments, the third connecting segment 44 can be a steel cylinder structure, and the third gamma shielding segment 43 is connected to the bottom end of the steel cylinder, which can effectively reduce the temperature of the third gamma shielding segment 43 and play a thermal shielding role.

[0092] In some embodiments, the third gamma shielding segment 43 can be a multilayer steel plate structure, which can enhance the shielding effect of gamma rays and improve the safety of reactor operation.

[0093] In some embodiments, the upper top plate 2211 of the first plug 20, the second top plate 3211 of the second plug 30, and the third top plate 4211 of the third plug 40 can all be low-alloy steel plates with certain thickness and rigidity, which can play a supporting role for each plug.

[0094] Referring to Figure 3 , Figures 10 to 13 , Figures 10 to 13 shows a cross-sectional partial enlarged view of the plug assembly,Figure 12 and Figure 13 The arrows in the above drawings show the air flow direction. In some embodiments, the reactor can further comprise an annular negative pressure air duct 101 located radially outside the container opening 111. The first, second and third plugs 20, 30 and 40 are respectively provided with first, second and third air ducts 201, 301 and 401. The first, second and third air ducts 201, 301 and 401 are respectively provided with first, second and third air inlets 2011, 3011 and 4011 for air to enter. The air entering the third air duct 401 can enter the second air duct 301. The air entering the second air duct 301 can enter the first air duct 201. The air entering the first air duct 201 can enter the annular negative pressure air duct 101. In this embodiment, the air ducts of the three plugs are connected, and cooperate with the annular negative pressure air duct 101 to achieve cooling and ventilation of the plug assembly, reduce the influence of high temperature in the reactor on the plug assembly, and thus ensure the stability of the plug assembly operation.

[0095] Referring to Figure 12 In some embodiments, the first air duct 201 and the annular negative pressure air duct 101 form a first communication air duct 91, the second air duct 301 and the first air duct 201 form a second communication air duct 92, and the third air duct 401 and the second air duct 301 form a third communication air duct 93. The first dynamic sealing structure 21 is arranged in the first communication air duct 91, the second dynamic sealing structure 31 is arranged in the second communication air duct 92, and the third dynamic sealing structure 41 is arranged in the third communication air duct. In this way, the cooling and ventilation of the plug assembly can be ensured while the sealing between the plugs is achieved.

[0096] Referring to Figures 11 to 13 The first plug 20 further comprises a first sealing plate 61 arranged above the upper top plate 2211, a first support cylinder 62 connecting the first sealing plate 61 and the upper top plate 2211, a first air-cooled surrounding cylinder 63 arranged radially outside the first support cylinder 62, and a first annular plate 64 connecting the first air-cooled surrounding cylinder 63 and the first support cylinder 62.

[0097] The second plug 30 further comprises a second sealing plate 71 arranged above the second top plate 3211, a second support cylinder 72 connecting the second sealing plate 71 and the second top plate 3211, a second air-cooled surrounding cylinder 73 arranged radially outside the second support cylinder 72, and a second annular plate 74 connecting the second air-cooled surrounding cylinder 73 and the second support cylinder 72.

[0098] The third plug 40 further comprises a third sealing plate 81 arranged above the third top plate 4211, a third support cylinder 82 connecting the third sealing plate 81 and the third top plate 4211, a third air-cooled surrounding cylinder 83 arranged radially outside the third support cylinder 82, and a third annular plate 84 connecting the third air-cooled surrounding cylinder 83 and the third support cylinder 82.

[0099] The first sealing plate 61, the upper top plate 2211, the first support cylinder 62, and the second air-cooling surrounding cylinder 73 form a first air duct 201, and the first air inlet 2011 is arranged on the upper top plate 2211, so as to cool the top of the first plug 20 and facilitate stable operation of the first plug 20.

[0100] The second sealing plate 71, the second top plate 3211, the second support cylinder 72, and the third air-cooling surrounding cylinder 83 form a second air duct 301, and the second air inlet 3011 is arranged on the second top plate 3211, so as to cool the top of the second plug 30 and facilitate stable operation of the second plug 30.

[0101] The third sealing plate 81, the third top plate 4211, and the third support cylinder 82 form a third air duct 401, and the third air inlet 4011 is arranged on the third top plate 4211, so as to cool the top of the third plug 40 and facilitate stable operation of the third plug 40.

[0102] In this way, the top of each plug can form an air duct, so as to cool the plug assembly and ensure stable operation of the plug assembly.

[0103] The container opening 111 of the stack container 11 is welded with the sealing body 94 of the first dynamic sealing structure 21, and the first annular plate 64 is welded with the matching part 95.

[0104] The first plug 20 further comprises a first sealing connecting part 66 connected with the first body section 22. The first sealing connecting part 66 is arranged on the radial outer side of the second air-cooling surrounding cylinder 73. The second annular plate 74 is welded with the sealing body 94 of the second dynamic sealing structure 31, and the first sealing connecting part 66 is welded with the matching part 95 of the second dynamic sealing structure 31.

[0105] The second plug 30 further comprises a second sealing connecting part 76 connected with the second body section 32. The second sealing connecting part 76 is arranged on the radial outer side of the third air-cooling surrounding cylinder 83. The third annular plate 84 is welded with the sealing body 94 of the third dynamic sealing structure 41, and the second sealing connecting part 76 is welded with the matching part 95 of the third dynamic sealing structure 41.

[0106] Referring to Figure 12 and Figure 13In some embodiments, the first air-cooling surrounding cylinder 63, the first annular plate 64, the first supporting cylinder 62 and the stack container 11 form a first communication air duct 91. The first air-cooling surrounding cylinder 63 forms a first air-cooling ventilation hole 631, and the first communication air duct 91 communicates with the annular negative pressure air duct 101 through the first air-cooling ventilation hole 631. In this embodiment, by forming the first communication air duct 91 and communicating with the annular negative pressure air duct 101, air can flow into the first air-cooling ventilation hole 631 from the first air inlet 2011, flow through the upper top plate of the first plug 20, and then flow out of the annular negative pressure air duct 101, thereby achieving ventilation and cooling of the top of the first plug 20 and facilitating stable operation of the first plug 20.

[0107] Referring to Figure 12 In some embodiments, the second air-cooling surrounding cylinder 73, the second annular plate 74, the second supporting cylinder 72 and the upper top plate 2211 of the first plug 20 form a second communication air duct 92. The second air-cooling surrounding cylinder 73 forms a second air-cooling ventilation hole 731, and the second communication air duct 92 communicates with the first air duct 201 through the second air-cooling ventilation hole 731, thereby achieving air flow between the top of the first plug 20 and the top of the second plug 30.

[0108] Referring to Figure 11 In some embodiments, the third air-cooling surrounding cylinder 83, the third annular plate 84, the third supporting cylinder 82 and the second top plate 3211 form a third communication air duct 93. The third air-cooling surrounding cylinder 83 forms a third air-cooling ventilation hole 831, and the third communication air duct 93 communicates with the second air duct 301 through the third air-cooling ventilation hole 831, thereby achieving air flow between the top of the second plug 30 and the top of the third plug 40.

[0109] Referring to Figure 12 In some embodiments, the first plug 20 can further include a first ventilation plate 65 arranged between the upper top plate 2211 and the first sealing plate 61. The first ventilation plate 65 forms a through hole, and the area below the first ventilation plate 65 where the first supporting cylinder 62 is located forms a first supporting cylinder ventilation hole 621 distributed in the circumferential direction. The air in the first air duct 201 flows into the area below the first ventilation plate 65 through the through hole of the first ventilation plate 65 and enters the first communication air duct 91 through the first supporting cylinder ventilation hole 621.

[0110] Correspondingly, the second plug 30 can further include a second ventilation plate arranged between the second top plate 3211 and the second sealing plate 71. The second ventilation plate forms a through hole, and the area below the second ventilation plate where the second supporting cylinder 72 is located forms a second supporting cylinder ventilation hole 721 distributed in the circumferential direction. The air in the second air duct 301 flows into the area below the second ventilation plate through the through hole of the second ventilation plate and enters the second communication air duct 92 through the second supporting cylinder ventilation hole 721. The air in the second communication air duct 92 enters the first air duct 201 through the second air-cooling ventilation hole 731.

[0111] The third plug 40 can further include a third ventilation plate arranged between the third top plate 4211 and the third sealing plate 81. The third ventilation plate forms a through hole, and the area below the third ventilation plate where the third support cylinder 82 is located forms third support cylinder ventilation holes distributed in the circumferential direction. The air in the third air duct 401 flows into the area below the third ventilation plate through the through hole of the third ventilation plate, and enters the third communication air duct 93 through the third support cylinder ventilation holes. The air in the third communication air duct 93 enters the second air duct 301 through the third air cooling ventilation hole 831. In this embodiment, by arranging the ventilation plate, the air in the first air duct 201, the second air duct 301 and the third air duct 401 respectively flows through the ventilation plate, and enters the communication air duct through the support cylinder ventilation holes of each plug, thereby achieving uniform cooling of the top of each plug and improving the stability of the operation of the plug assembly.

[0112] The first plug 20 is rotatably connected to the container opening 111 through the first bearing 202. The reactor can further include a first driving mechanism 204 for driving the first plug 20 to rotate relative to the reactor vessel 11. The first driving mechanism 204 can be arranged on the reactor vessel 11.

[0113] The second plug 30 is rotatably connected to the first through hole 27 through the second bearing 302. The reactor can further include a second driving mechanism 304 for driving the second plug 30 to rotate relative to the first plug 20. The second driving mechanism 304 can be arranged on the first plug 20.

[0114] The third plug 40 is rotatably connected to the second through hole 39 through the third bearing 402. The reactor can further include a third driving mechanism 404 for driving the third plug 40 to rotate relative to the second plug 30. The third driving mechanism 404 can be arranged on the second plug 30.

[0115] In some embodiments, the first plug 20 can further include a first gear ring 203 arranged on the first support cylinder 62, and the first driving mechanism 204 is engaged with the first gear ring 203 through a transmission gear to drive the first plug 20 to rotate relative to the reactor vessel 11.

[0116] In some embodiments, the second plug 30 can further include a second gear ring 303 arranged on the second support cylinder 72, and the second driving mechanism 304 is engaged with the second gear ring 303 through a transmission gear to drive the second plug 30 to rotate relative to the first plug 20.

[0117] In some embodiments, the third plug 40 can further include a third gear ring 403 arranged on the third support cylinder 82, and the third driving mechanism 404 is engaged with the third gear ring 403 through a transmission gear to drive the third plug 40 to rotate relative to the second plug 30.

[0118] The plug assembly provided by the embodiment of the application has the advantages that three plugs are arranged, the size of the first through hole 27 is greater than the radius of the first plug 20, the moving range of the refueling machine is increased, the size of the first plug 20 is reduced, the arrangement space of the plug assembly is optimized, and the economy and the refueling efficiency of the reactor are improved; the safety of the reactor in operation is ensured by arranging the multiple shielding layers and the dynamic sealing structure; the stability of the plug assembly in operation is ensured by forming the multiple air ducts on the top of the plug assembly.

[0119] It should be further understood that the embodiments and the features in the embodiments of the application can be combined with each other to obtain new embodiments without conflicts.

[0120] The above is only a specific implementation of the application, but the protection scope of the application is not limited thereto, and the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A pet cock assembly for a reactor, the reactor including a reactor vessel, a core assembly disposed in the reactor vessel, the reactor vessel including a vessel opening coaxial with the core assembly, the reactor further including a refueling machine, characterized by, The plug assembly comprises: a first plug rotatably arranged at a vessel opening of a reactor vessel of the reactor, the first plug being provided with a first through hole eccentric to the first plug, the first through hole having a size greater than a radius of the first plug; a second plug arranged at the first through hole of the first plug and rotatable relative to the first plug, the second plug being provided with a second through hole eccentric to the second plug; a third plug arranged at the second through hole of the second plug and rotatable relative to the second plug, the third plug being provided with a third through hole eccentric to the third plug; the refueling machine is arranged at the third through hole of the third plug; the reactor further comprises an annular negative pressure air duct located radially outward of the vessel opening; the first plug, the second plug and the third plug are respectively provided with a first air duct, a second air duct and a third air duct, the first air duct, the second air duct and the third air duct are respectively provided with a first air inlet, a second air inlet and a third air inlet for air to enter; the air entering the third air duct can enter the second air duct; the air entering the second air duct can enter the first air duct; the air entering the first air duct can enter the annular negative pressure air duct.

2. The faucet assembly of claim 1, wherein The distance between the center of the second through hole and the center of the second plug is equal to one half of the radius of the core assembly.

3. The faucet assembly of claim 1, wherein The reactor further comprises a plurality of control rods and a plurality of control rod drive mechanisms connected with the control rods; The second plug comprises a plurality of control rod drive mechanism mounting sockets for mounting the plurality of control rod drive mechanisms; The plurality of control rod drive mechanism mounting sockets are arranged within a predetermined circumference, and the predetermined circumference can be in a position concentric to the first plug by rotating the second plug relative to the first plug.

4. The faucet assembly of claim 1, wherein The center of the second through hole is collinear with the center of the first through hole and the center of the first plug.

5. The faucet assembly of claim 1, wherein Further comprising: a first dynamic sealing structure for sealing the first plug and the vessel opening of the reactor vessel; a second dynamic sealing structure for sealing the second plug and the first through hole of the first plug; a third dynamic sealing structure for sealing the third plug and the second through hole of the second plug; The difference between the diameter of the first plug and the diameter of the core assembly is equal to the sum of the ring width of the first dynamic sealing structure, the ring width of the second dynamic sealing structure and the ring width of the third dynamic sealing structure.

6. The faucet assembly of claim 1, wherein, The distance between the center of the third through hole of the third plug and the center of the first plug is equal to twice the distance between the center of the second plug and the center of the first plug.

7. The faucet assembly of claim 1, wherein The first plug comprises a first body segment, a first gamma shielding segment and a first connecting segment, the first gamma shielding segment being connected with the first body segment through the first connecting segment; The first body segment faces the vessel opening of the reactor vessel, and the first connecting segment and the first gamma shielding segment enter the interior of the reactor vessel.

8. The faucet assembly of claim 3, wherein, The second plug further comprises a second body segment, a second gamma shielding segment, and a second connecting segment, the second gamma shielding segment being connected with the second body segment through the second connecting segment; The plurality of control rod drive mechanism mounting nozzles are arranged on the second body segment; The second plug further comprises a control rod protection member, the plurality of control rods extending downward from the radial inner side of the control rod protection member.

9. The faucet assembly of claim 1, wherein, The third plug comprises a third body segment, a third gamma shielding segment, and a third connecting segment, the third gamma shielding segment being connected with the third body segment through the third connecting segment.

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