Dual-cable-tray reactor head structure

Abstract

A dual-cable-tray reactor head structure, comprising a hoisting assembly (30), an anti-seismic assembly (40), a first cable tray (10), and a second cable tray (20) which are arranged above a top cover (100) of a pressure vessel and located at the periphery of a control rod drive mechanism. The hoisting assembly (30) comprises a plurality of hoisting rods (31) and a support frame (32). The plurality of hoisting rods (31) are spaced part in the circumferential direction of the top cover (100) and are vertically connected to the top cover (100). The support frame (32) is connected to the tops of the plurality of hoisting rods (31). The anti-seismic assembly (40) is arranged above the top cover (100) and located below the support frame (32). The first cable tray (10) and the second cable tray (20) are symmetrically distributed on two sides of a reactor core, and are pivotably connected to the anti-seismic assembly (40). The dual-cable-tray reactor head structure can reduce the difficulty and time of center-of-gravity leveling in a hoisting stage during nuclear power plant installation and refueling outage, thereby improving hoisting efficiency and safety; said structure meets the segregation requirements for reactor head cables, thereby ensuring sufficient safety redundancy margin for the reactor head cables; and said structure enhances the convenience and economy of cable installation, maintenance, and replacement.

Description

Double cable tray type reactor head top structure TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear power reactors, in particular to a double cable tray type reactor head top structure. BACKGROUND

[0002] In a nuclear power plant, the reactor head assembly is one of the important components of the reactor system, which is installed above the reactor pressure vessel (RPV) top cover, fixed on the RPV top cover during normal operation, and hoisted and played back together with the RPV top cover and the control rod drive mechanism (CRDM) during shutdown and refueling. The main functions of the reactor head assembly include: (a) during reactor refueling maintenance, hoist the pressure vessel top cover as a whole, simple and fast disassembly and assembly operation; (b) provide seismic support for the CRDM to limit the excessive deformation of the CRDM under seismic conditions to maintain its normal function and ensure its functional integrity under accident conditions; (c) provide a cooling and ventilation passage for the control rod drive mechanism yoke coil to ensure the normal operation of the control rod drive mechanism; (d) guide all rod control and rod position system (RGL) cables, reactor core measurement system (RIC) cables, release components and vibration monitoring system (KIR) cables in the reactor head region to the specified civil interface.

[0003] Among the above functions, item (a) is mainly completed by the lifting assembly. The upper part of the lifting assembly is connected with the ring lifting hook, and the lower part is connected with the reactor head and top cover structure, which plays a lifting function during refueling maintenance. The cable laying function of item (d) is mainly completed by the cable tray, cable bracket and cable bridge of the reactor head.

[0004] A reactor head assembly in the prior art adopts a single-sided double-layer cable tray scheme. RIC measurement cables, RGL measurement cables and KIR cables are laid on the upper cable bracket and the upper cable bridge. The RIC cables are laid in two columns on the upper cable tray, i.e. column A (group A and group B) and column B (group C and group D). The RGL measurement cables are arranged in four columns, and a partition with a thickness not less than 10 mm is used between the columns. The RGL low-voltage cables are laid on the lower cable bracket and the lower cable bridge. The reactor head lifting assembly is a three-jack structure, and the angle spacing between the jacks is 60°. The jacks are inclined to the center hook. The upper U-shaped wedge of the jack is connected with the hook through a pin shaft, and the lower U-shaped wedge of the jack is connected with the ring guide rail connecting block on the star-shaped support through a pin shaft. The above method has the following defects:

[0005] (1) The existing unilateral cable tray scheme is relatively concentrated, and the number is relatively large (the number of RIC measurement cables in the general pressurized water reactor nuclear power plant is 10-50, the number of RGL rod position measurement cables is 60-90, the number of RGL rod control low-voltage cables is 60-90, and there are 2-10 KIR cables). The overall structure size of the tray is large, and the weight is heavy. During laying, it may be necessary to stack multiple layers due to the size of the tray, increasing the difficulty of maintenance and replacement. As the importance of nuclear power safety increases, measurement cables need to bear more measurement functions, so the size of the new measurement cable has increased compared to the previous cable size, further increasing the burden of the cable tray.

[0006] (2) The unilateral tray causes the overall center of gravity of the reactor top to be unbalanced. During hoisting, the center of gravity needs to be leveled, increasing the complexity and time of the operation.

[0007] (3) All cables need to be introduced to the same direction of the cable tray after being introduced from the reactor top or the top of the CRDM. Some cables that are far away from the tray are long and difficult to lay.

[0008] (4) The cables are relatively concentrated and not physically separated (RIC measurement cables are not separated into AB and CD groups; although RGL measurement cables are separated, they are only separated by a partition on the tray, and the distance is still relatively close). There is a risk of signal interference, and it is difficult to fully meet the single fault criterion requirement in the event of a fire or other emergency (i.e., when a fire or other emergency occurs on one side of the plant, half of the cables can still be used).

[0009] (5) According to the latest core control mode requirements of the nuclear power plant, the RIC measurement reactor top cables need to be laid in four redundant protection sequences on the reactor top cable tray. The existing scheme cannot fully meet the requirements due to the size limitation of the tray.

[0010] (6) The existing upper lifting fixture structure occupies a large space due to the radial arrangement of the lifting rods between the hook and the star-shaped support ring-shaped guide rail connecting block. If the size of the cable tray is increased (the width is increased), it is easy to interfere with the cable tray when it is erected. This results in a small operable space on the reactor top, which is not conducive to installation and maintenance operations.

[0011] (7) Under the existing three-lifting rod assembly structure, the tray can only be arranged between the two lifting rods. Due to the non-axially symmetric structure of the three-lifting rod, the selection of the tray arrangement position is small. If the size or number of the tray is increased, it may be difficult to find a suitable position.

[0012] (8) The original cable tray is simply placed on the reactor pool without displacement limiting measures. During an earthquake or other transient conditions, the cable tray may displace, even causing the entire reactor top and reactor to vibrate, resulting in a safety risk. SUMMARY

[0013] The technical problem solved by the present application is to provide a double cable tray type reactor head structure sharing cable laying through two cable trays.

[0014] The technical solution adopted by the present application to solve its technical problem is to provide a double cable tray type reactor head structure, comprising a hanging assembly arranged above a top cover of a pressure vessel and at a periphery of a control rod drive mechanism, an anti-seismic assembly, a first cable tray and a second cable tray for cable laying;

[0015] The hanging assembly comprises a plurality of hangers and a support frame, the plurality of hangers are arranged in a circumferential direction of the top cover and vertically connected to the top cover, and the support frame is connected to the top of the plurality of hangers; the anti-seismic assembly is arranged above the top cover and below the support frame; the first cable tray and the second cable tray are symmetrically distributed on both sides of the reactor center and reversibly connected to the anti-seismic assembly;

[0016] During reactor operation, the first cable tray and the second cable tray are in a flat state and are lapped on a top platform of a reactor pool; during reactor shutdown and refueling, the first cable tray and the second cable tray are in a vertical state.

[0017] In some embodiments, when the first cable tray and the second cable tray are in the flat state, the included angle with the horizontal plane is -20°-40°;

[0018] When the first cable tray and the second cable tray are in the vertical state, the included angle with the vertical plane is -20°-40°.

[0019] In some embodiments, the horizontal distance between the center line of the first cable tray and the center line of the second cable tray is 0-1000mm.

[0020] In some embodiments, the hanging assembly comprises four hangers; and the support frame is a cross-shaped support frame or an I-shaped support frame.

[0021] In some embodiments, the double cable tray type reactor head structure further comprises at least one set of first anti-seismic supporting assemblies and at least one set of second anti-seismic supporting assemblies.

[0022] The first anti-seismic supporting assembly is arranged between the first cable tray and the top platform of the reactor pool and connects the first cable tray in the flat state to the top platform of the reactor pool.

[0023] The second anti-vibration support assembly is arranged between the second cable bridge and the reactor pool top platform, and connects the second cable bridge in a flat state to the reactor pool top platform.

[0024] In some embodiments, the first anti-vibration support assembly comprises a perforated plate arranged on a side of the first cable bridge facing the reactor pool top platform, a connecting seat fixed on the reactor pool top platform, and a connecting bolt;

[0025] When the first cable bridge is flat, the perforated plate is fitted to the connecting seat, and the connecting bolt is arranged through the connecting seat and the perforated plate to connect the perforated plate to the connecting seat.

[0026] In some embodiments, the first cable bridge has a length of 2000mm-8000mm and a width of 500mm-2000mm.

[0027] The second cable bridge has a length of 2000mm-8000mm and a width of 500mm-2000mm.

[0028] In some embodiments, the first cable bridge comprises at least one first bridge layer; the first bridge layer comprises a first bridge and at least one first partition plate; one end of the first bridge is connected to the anti-vibration assembly through a first support assembly, and the opposite end of the first bridge is provided with a first arc-shaped plate; the first partition plate is arranged on the first bridge and extends along the length direction of the first bridge to divide the space on the first bridge into at least two columns of channels for laying cables.

[0029] The second cable bridge comprises at least one second bridge layer; the second bridge layer comprises a second bridge and at least one second partition plate; one end of the second bridge is connected to the anti-vibration assembly through a second support assembly, and the opposite end of the second bridge is provided with a second arc-shaped plate; the second partition plate is arranged on the second bridge and extends along the length direction of the second bridge to divide the space on the second bridge into at least two columns of channels for laying cables.

[0030] In some embodiments, the first cable bridge further comprises first protective railings arranged on at least two sides of the first bridge.

[0031] The second cable bridge further comprises second protective railings arranged on at least two sides of the second bridge.

[0032] In some embodiments, the hanging assembly further comprises a hook unit connected to the center position of the support frame, and a working platform arranged on the support frame and located at the periphery of the hook unit.

[0033] In some embodiments, the anti-seismic assembly comprises an anti-seismic ring; each of the suspending rods of the suspending assembly is connected to the top cover vertically through the anti-seismic ring.

[0034] In some embodiments, the anti-seismic assembly further comprises at least one anti-seismic tie rod; one end of the anti-seismic tie rod is connected to the anti-seismic ring, and the other end is connected to a wall surface of the reactor pool.

[0035] In some embodiments, the double-cable tray type reactor head structure further comprises a cable bracket unit connected to the anti-seismic assembly and located at the top of the control rod drive mechanism.

[0036] The first cable tray is provided with a first connecting frame, and the second cable tray is provided with a second connecting frame.

[0037] In the vertical state of the first cable tray, the end of the first connecting frame is connected to the cable bracket unit; in the vertical state of the second cable tray, the end of the second connecting frame is connected to the cable bracket unit.

[0038] In some embodiments, the double-cable tray type reactor head structure further comprises a cable grid; the cable grid is arranged on the top cover and below the anti-seismic assembly.

[0039] The beneficial effects of the present application are as follows: through the symmetrical arrangement of the two cable trays on both sides of the reactor head, the overall gravity center of the reactor head is relatively balanced, the difficulty and time of gravity center leveling during the hoisting stage of the installation and refueling overhaul of the nuclear power plant are reduced, and the hoisting efficiency and safety are improved; the arrangement of the two cable trays on the reactor head can separate the reactor head cables on the two cable trays, realize the columnar requirement of the reactor head cables, reduce the number, weight, number of layers and part of the cable length of the cables laid on one side of the cable tray, and ensure the safety redundancy of the reactor head cables; the staff can work on both sides at the same time, thereby improving the convenience and economy of cable laying, maintenance and replacement. BRIEF DESCRIPTION OF DRAWINGS

[0040] The present application will be further described below in conjunction with the drawings and embodiments, and the drawings are as follows:

[0041] Fig. 1 is a structural schematic diagram of the double-cable tray type reactor head structure of an embodiment of the present application in a flat state of the cable tray;

[0042] Fig. 2 is a schematic diagram of the symmetrical arrangement of the two cable trays in Fig. 1;

[0043] Fig. 3 is a structural schematic diagram of the support frame in Fig. 1;

[0044] Fig. 4 is a structural schematic diagram of the cable tray in Fig. 1 overlapped on the top platform of the reactor pool;

[0045] Figure 5 is a structural schematic diagram of the first anti-seismic support assembly (the second anti-seismic support assembly) in Figure 4;

[0046] Figure 6 is a structural schematic diagram of a double-cable-tray type reactor head structure in an embodiment of the present application in a vertical state of the cable tray;

[0047] Figure 7 is a structural schematic diagram of a double-cable-tray type reactor head structure in another embodiment of the present application in a horizontal state of the cable tray;

[0048] Figure 8 is a structural schematic diagram of a support frame in Figure 7. DETAILED DESCRIPTION

[0049] In order to have a clearer understanding of the technical features, objects and effects of the present application, the specific embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0050] The double-cable-tray type reactor head structure of the present application is arranged on the top of the reactor as a whole and specifically on the top cover of the pressure vessel.

[0051] As shown in Figure 1, the double-cable-tray type reactor head structure in an embodiment of the present application can include a hoisting assembly 30, an anti-seismic assembly 40, a first cable tray 10 and a second cable tray 20. The hoisting assembly 30, the anti-seismic assembly 40, the first cable tray 10 and the second cable tray 20 are all arranged above the top cover 100 of the pressure vessel and simultaneously at the periphery of the control rod drive mechanism.

[0052] The hoisting assembly 30 is connected to the top cover 100 and can form an integral part with the top cover 100. During reactor shutdown and refueling, the hoisting assembly 30, the top cover 100 and the control rod drive mechanism on the top cover 100 can be hoisted away from the pressure vessel or hoisted back to the pressure vessel by connecting the hoisting assembly 30 to hoisting equipment. The anti-seismic assembly 40 can be connected to and elevated above the top cover 100 by the hoisting assembly 30, thereby playing a role of strengthening structure and anti-seismic for the whole reactor head structure. The first cable tray 10 and the second cable tray 20 are symmetrically distributed on both sides of the reactor center (also on both sides of the top cover center). The first cable tray 10 and the second cable tray 20 are both used for cable laying, so that various cables led out of the reactor head can be laid on the two cable trays, thereby reducing the number, weight and number of layers of cables laid on a single cable tray.

[0053] The arrangement of the first cable tray 10 and the second cable tray 20 on the reactor head not only can share the cable laying, but also can be smaller in size and weight than the single cable tray arrangement, thereby reducing the requirement for the strength of the cable tray and ensuring the safety of the reactor head equipment. The staff can carry out work in parallel on the two cable trays, thereby saving time for cable laying.

[0054] Referring to FIG. 2, the first cable tray 10 and the second cable tray 20 are symmetrically distributed on both sides of the reactor center, and the gravity center is as close to the reactor center as possible, so as to reduce the complexity and time of gravity center leveling operation during operation and maintenance. The horizontal distance h between the center line of the first cable tray 10 and the center line of the second cable tray 20 is 0-1000 mm; when the horizontal distance h between the center line of the first cable tray 10 and the center line of the second cable tray 20 is 0, the two are completely symmetrical.

[0055] Specifically, in combination with FIG. 1 and FIG. 3, the hoisting assembly 30 can include a plurality of hangers 31 and a support frame 32. The plurality of hangers 31 are arranged along the circumference of the top cover 100 and vertically connected to the top cover 100, and the top cover 100 is provided with a lifting eye for connecting with the hangers 31. For the circular top cover 100, the plurality of hangers 31 are uniformly arranged along the circumference of the top cover 100. The support frame 32 can be connected to the top of the plurality of hangers 31 away from the top cover 100 by a pin shaft or welding, etc., to connect the plurality of hangers 31 together. The support frame 32 is supported and connected to the top cover 100 by the hangers 31, and is also above the control rod drive mechanism.

[0056] According to actual needs, the hangers 31 can be two, three, four or more.

[0057] The hangers 31 are preferably circular rods, and the diameter can be 50-300 mm.

[0058] In the embodiment shown in FIG. 1 and FIG. 3, the hoisting assembly 30 includes four hangers 31, which are uniformly arranged along the circumference of the top cover 100, and the included angle between every two adjacent hangers 31 is 90°. The support frame 32 is a cross-shaped support frame, and four ends of the cross-shaped support frame are respectively connected to the top of the four hangers 31. The cross-shaped support frame can be specifically formed by two cross beams 321 being perpendicularly and crossly connected, and each cross beam 321 can be made of an I-beam or a flat steel plate. Alternatively, the cross-shaped support frame can be formed by four cross beams 321 being reflectively connected to a center column, and each cross beam 321 can be made of an I-beam or a flat steel plate.

[0059] It can be understood that in other embodiments, the hoisting assembly 30 includes three hangers 31, and the support frame 32 is a triangular support frame connected to the top of the three hangers 31. The triangular support frame can be specifically formed by three cross beams 321 being perpendicularly and crossly connected.

[0060] In some embodiments, the hoisting assembly 30 further comprises a hook unit 33 and a working platform 34. The hook unit 33 is connected to the center of the support frame 32 as a hoisting point for connecting with hoisting equipment. The working platform 34 is arranged on the support frame 32 and at the periphery of the hook unit 33, and operators can perform relevant operations such as installing and dismounting hooks, equipment maintenance, etc. on the working platform 34.

[0061] The anti-seismic assembly 40 is arranged above the top cover 100 and below the support frame 32. The anti-seismic assembly 40 further comprises an anti-seismic ring 41 which is elevated by the hoisting rods 31 of the hoisting assembly 30 and connected above the top cover 100. In the embodiment shown in FIG. 1, each hoisting rod 31 of the hoisting assembly 30 vertically penetrates the anti-seismic ring 41 and is fixed opposite to the anti-seismic ring 41, so that the anti-seismic ring 41 is connected to the four hoisting rods 31. The anti-seismic ring 41 is axially close to the support frame 32 and below the support frame 32.

[0062] In some embodiments, the anti-seismic assembly 40 further comprises at least one anti-seismic tie rod (not shown). One end of the anti-seismic tie rod is connected to the anti-seismic ring 41, and the other end is connected to the wall surface of the reactor pool. Preferably, there are 4-5 anti-seismic tie rods which are arranged at intervals along the circumference of the anti-seismic ring 41 to generate radial tension on the anti-seismic ring 41, thereby tightening the anti-seismic ring 41 to the wall surface of the reactor pool, improving stability and seismic effect.

[0063] The first cable bridge 10 and the second cable bridge 20 are symmetrically distributed on both sides of the reactor center and reversibly connected to the anti-seismic assembly 40, specifically to the anti-seismic ring 41 of the anti-seismic assembly 40. The arrangement of the four hoisting rods 31 of the hoisting assembly 30 defines four uniform spaces on the top of the reactor, which also serve as accommodation spaces for the first cable bridge 10 and the second cable bridge 20. In combination with the symmetric distribution of the first cable bridge 10 and the second cable bridge 20, the first cable bridge 10 and the second cable bridge 20 are located in diagonally opposite two spaces, which is conducive to the balance of the overall center of gravity of the reactor top.

[0064] The first cable bridge 10 and the second cable bridge 20 are reversibly arranged on the top of the reactor and can be switched between a flat state and an upright state. When the reactor is in operation, the first cable bridge 10 and the second cable bridge 20 are in the flat state and are lapped on the top platform 200 of the reactor pool, as shown in FIG. 1 and FIG. 4. When the reactor is shut down for refueling, the first cable bridge 10 and the second cable bridge 20 are in the upright state, as shown in FIG. 6.

[0065] In the flat state, the first cable bridge 10 and the second cable bridge 20 can form an angle of -20°-40° with the horizontal plane, for example, -10°, -5°, 0°, 10°, etc. In the vertical state, the first cable bridge 10 and the second cable bridge 20 can form an angle of -20°-40° with the vertical plane, for example, -10°, -5°, 0°, 10°, etc.

[0066] In the vertical state, the first cable bridge 10 and the second cable bridge 20 are accommodated in the space between the cross beams 321 of the support frame 32 and do not interfere with the support frame 32. In the flat state, the first cable bridge 10 and the second cable bridge 20 extend away from the top of the reactor pool and are lapped on the top platform 200 of the reactor pool.

[0067] In order to avoid displacement of the first cable bridge 10 and the second cable bridge 20 when lapped on the top platform 200 of the reactor pool in the flat state under the action of earthquake or other transient conditions, in some embodiments, the double-cable bridge type reactor top structure further comprises at least one set of first anti-seismic support assemblies 50 and at least one set of second anti-seismic support assemblies 60.

[0068] The first anti-seismic support assembly 50 is arranged between the first cable bridge 10 and the top platform 200 of the reactor pool, and connects the first cable bridge 10 in the flat state to the top platform 200 of the reactor pool, so that the first cable bridge 10 and the top platform 200 of the reactor pool are relatively fixed, supporting the first cable bridge 10 while limiting displacement of the first cable bridge 10 in the vertical and horizontal directions. The second anti-seismic support assembly 60 is arranged between the second cable bridge 20 and the top platform 200 of the reactor pool, and connects the second cable bridge 20 in the flat state to the top platform 200 of the reactor pool, so that the second cable bridge 20 and the top platform 200 of the reactor pool are relatively fixed, supporting the second cable bridge 20 while limiting displacement of the second cable bridge 20 in the vertical and horizontal directions.

[0069] The first anti-seismic support assembly 50 and the second anti-seismic support assembly 60 have the same effect, and both can be implemented by the same structure. Taking the first anti-seismic support assembly 50 as an example, referring to FIGS. 4 and 5, the first anti-seismic support assembly 50 can specifically include a perforated plate 51, a connecting seat 52, and a connecting bolt 53. The perforated plate 51 is arranged on the side of the first cable bridge 10 facing the top platform 200 of the reactor pool, the connecting seat 52 is fixed on the top platform 200 of the reactor pool, and the connecting bolt 53 is adapted to the holes of the perforated plate 51 and the connecting holes on the connecting seat 52. When the first cable bridge 10 is flat, the perforated plate 51 is fitted onto the connecting seat 52, and the connecting bolt 53 is arranged through the connecting seat 52 and the perforated plate 51 to connect the perforated plate 51 to the connecting seat 52.

[0070] The connecting bolt 53 leaves a gap between the hole of the hole plate 51 and the connecting hole on the connecting seat 52, and the gap is preferably 0.2mm-5mm. The gap ensures that the cable bridge (the first cable bridge 10 and the second cable bridge 20) and the pool can be effectively installed when thermal expansion or shrinkage occurs under different environmental temperature conditions.

[0071] In a preferred embodiment, the connecting seat 52 further comprises a bottom plate 521 and two vertical plates 522. The bottom plate 521 is fixed on the reactor pool top platform 200 by expansion bolts, and the two vertical plates 522 are parallel and vertically connected to the bottom plate 521. Each vertical plate 522 is provided with a connecting hole. When the hole plate 51 is fitted between the two vertical plates 522, the hole on the hole plate 51 is in communication with the connecting hole on the vertical plate 522. The connecting bolt 53 can be transversely inserted from the outside of a vertical plate 522 to connect the vertical plate 522 and the hole plate 51. The connecting bolt 53 is detachably connected to the connecting seat 52 and the hole plate 51.

[0072] The second anti-seismic support assembly 60 is the same as the first anti-seismic support assembly 50, and will not be described here.

[0073] The first cable bridge 10 is preferably connected to the reactor pool top platform 200 by two or more first anti-seismic support assemblies 50, and the second cable bridge 20 is preferably connected to the reactor pool top platform 200 by two or more second anti-seismic support assemblies 60.

[0074] Alternatively, the length of the first cable bridge 10 can be, but is not limited to, 2000mm-8000mm, and the width can be, but is not limited to, 500mm-2000mm. The length of the second cable bridge 20 can be, but is not limited to, 2000mm-8000mm, and the width can be, but is not limited to, 500mm-2000mm.

[0075] As shown in FIG. 1, above the top cover 100, the first cable bridge 10 has opposite two ends in the length direction, one end can be connected to the anti-seismic ring 41 through the first support assembly 15, and the opposite end can extend away from the reactor center. Moreover, the first cable bridge 10 can rotate relative to the anti-seismic ring 41 through the first support assembly 15, from the vertical state to the flat state, or from the flat state to the vertical state.

[0076] The first cable bridge 10 comprises at least one first bridge layer. The first bridge layer further comprises a first bridge 11 and at least one first partition plate 12. One end of the first bridge 11 is connected to the anti-seismic assembly 40 through the first support assembly 15. The first partition plate 12 is arranged on the first bridge 11 and extends along the length direction of the first bridge 11, dividing the space on the first bridge 11 into at least two columns of channels for laying cables.

[0077] The first partition plate 12 is in a number of 1-8, so that the cables are arranged in columns or are convenient to lay on the first bridge 11, and the interval between the first partition plates 12 is 10-200 mm.

[0078] The first bridge 11 is provided with a first arc-shaped plate 13 at the opposite end, so that the cables are led out from the end of the first bridge 11, and the cables are prevented from being in a state of vertically falling at right angles after leaving the first bridge 11, which affects the usability of the cables. The first arc-shaped plate 13 is preferably a circular arc plate with a radius of 50-350 mm.

[0079] In order to prevent the cables from falling off from the side of the first bridge 11, the first cable bridge 10 further comprises a first protective rail 14, which is arranged on at least two sides of the first bridge 11, for example, the two sides in the length direction of the first bridge 11. The first protective rail 14 can be formed by arranging a plurality of rod members on the first bridge 11.

[0080] As shown in FIG. 1, above the top cover 100, the second cable bridge 20 has opposite ends in the length direction, one end of which is connected to the anti-seismic ring 41 through the second support assembly 25, and the opposite end extends away from the center of the reactor. Moreover, the second cable bridge 20 can rotate relative to the anti-seismic ring 41 through the second support assembly 25, from the vertical state to the flat state, or from the flat state to the vertical state.

[0081] The second cable bridge 20 comprises at least one second bridge layer. The second bridge layer further comprises a second bridge 21 and at least one second partition plate 22. One end of the second bridge 21 is connected to the anti-seismic assembly 40 through the second support assembly 25. The second partition plate 22 is arranged on the second bridge 21 and extends along the length direction of the second bridge 21, so as to divide the space on the second bridge 21 into at least two channels for laying cables.

[0082] The second partition plate 22 is in a number of 1-8, so that the cables are arranged in columns or are convenient to lay on the second bridge 21, and the interval between the second partition plates 22 is 10-200 mm.

[0083] The second bridge 21 is provided with a second arc-shaped plate 23 at the opposite end, so that the cables are led out from the end of the second bridge 21, and the cables are prevented from being in a state of vertically falling at right angles after leaving the second bridge 21, which affects the usability of the cables. The second arc-shaped plate 23 is preferably a circular arc plate with a radius of 50-350 mm.

[0084] In order to prevent the cables from falling off from the side of the second bridge 21, the second cable bridge 20 further comprises a second protective rail 24, which is arranged on at least two sides of the second bridge 21, for example, the two sides in the length direction of the second bridge 21. The second protective rail 24 can be formed by arranging a plurality of rod members on the second bridge 21.

[0085] In the embodiment shown in FIG. 1, the double-cable tray type reactor head structure can further include a cable tray unit 70 and a cable rack 80. The cable tray unit 70 is connected to the seismic assembly 40 and is located at the top of the control rod drive mechanism; the cable rack 80 is arranged on the top cover 100 and is below the seismic assembly 40.

[0086] Specifically, the cable tray unit 70 can include at least one layer of cable trays, which are arranged transversely below the support frame 32 and at the top of the control rod drive mechanism. Different layers of cable trays can be used to support different types of cables. The cable rack 80 is vertically connected below the seismic ring 41 and is used to support cables.

[0087] In order to keep the first cable tray 10 and the second cable tray 20 stable in the erected state, the first cable tray 10 is provided with a first connecting frame 16, and the second cable tray 20 is provided with a second connecting frame 26. In the erected state, the end of the first connecting frame 16 is connected to the cable tray unit 70, and in the erected state, the end of the second connecting frame 26 is connected to the cable tray unit 70.

[0088] The first connecting frame 16 can be connected to the first bridge 11 or the first partition 12 of the first cable tray 10, and the second connecting frame 26 can be connected to the second bridge 21 or the second partition 22 of the second cable tray 20, according to the cable laying without interference.

[0089] Alternatively, the first connecting frame 16 and the second connecting frame 26 can each be a rectangular or triangular frame, and a U-shaped connector or the like is arranged at the end to connect the cable tray unit.

[0090] In a preferred embodiment, the first cable tray 10 has a first tray layer, which can be understood as a single-layer structure; and the second cable tray 20 has upper and lower second tray layers, which can be understood as a double-layer structure. The cable support unit 70 includes upper and lower cable supports. At the top of the reactor core, the RIC measuring cables and the KIR cables are supported along the cable grid 80, and after being branched from the cable support unit 70, the RGL rod position measuring cables are supported on the upper cable support of the cable support unit 70 and are branched, and are laid on the first tray layer of the first cable tray 10 and the upper second tray layer of the second cable tray 20, so as to realize physical separation and meet the single failure criterion requirement in the case of a fire or other emergency (i.e., when a fire or other emergency occurs on one side of the plant, half of the cables can still be used), and finally are drawn out from the ends of the first cable tray 10 and the second cable tray 20 and connected to the cable cabinet. After the RGL rod control low-voltage cables are supported on the lower cable support of the cable support unit 70 and are branched, they are laid on the lower second tray layer of the second cable tray 20, and finally are drawn out from the end of the second cable tray 20 and connected to the cable cabinet.

[0091] As shown in FIGS. 7 and 8, the double-cable tray type reactor core top structure of another embodiment of the present application includes a hoisting assembly 30, a seismic assembly 40, a first cable tray 10, and a second cable tray 20. The hoisting assembly 30, the seismic assembly 40, the first cable tray 10, and the second cable tray 20 are all arranged above the top cover 100 of the pressure vessel and are located in the periphery of the control rod drive mechanism.

[0092] The hoisting assembly 30 is connected to the top cover 100 and can be integrated with the top cover 100. During reactor shutdown and refueling, the hoisting assembly 30, the top cover 100, and the control rod drive mechanism on the top cover 100 can be lifted off the pressure vessel or lifted back onto the pressure vessel by connecting the hoisting assembly 30 to hoisting equipment. The seismic assembly 40 can be connected to and elevated above the top cover 100 by the hoisting assembly 30, and plays a role in strengthening the structure and resisting earthquakes for the entire reactor core top structure. The first cable tray 10 and the second cable tray 20 are symmetrically arranged on both sides of the reactor core (also on both sides of the center of the top cover), and are used for cable laying, so that the various cables drawn out from the reactor core top can be laid on the two cable trays, thereby reducing the number, weight, and number of layers of the cables laid on a single cable tray.

[0093] The specific arrangements of the hoisting assembly 30, the seismic assembly 40, the first cable tray 10, and the second cable tray 20 can be referred to the above-described embodiments shown in FIGS. 1 to 6, and will not be described here again.

[0094] Different from the embodiments shown in Figs. 1-6, in the present embodiment, the hanger assembly 30 comprises four hanger rods 31, and the support frame 32 of the hanger assembly 30 is an I-shaped support frame. The four ends of the I-shaped support frame are respectively connected to the top of the four hanger rods 31. The I-shaped support frame can be formed by three cross beams 322 arranged in an I shape, and each cross beam 322 can be made of an I-shaped steel or a flat steel plate.

[0095] In the I-shaped support frame, two parallel cross beams 322 are connected by a cross beam 322 perpendicular thereto, and the space between the two parallel cross beams 322 can be used as a containing space for the first cable bridge 10 and the second cable bridge 20. When the first cable bridge 10 and the second cable bridge 20 are in the erected state, they are accommodated in the space between the two cross beams 322 and do not interfere with the support frame 32.

[0096] For the cross-shaped support frame and the I-shaped support frame, the cross beams 321, 322 can be made of steel with a width of 20-500 mm and a height of 300-1000 mm.

[0097] In addition, with reference to Figs. 1 and 7, the double-cable bridge type reactor head structure of the present application further comprises a cover (not shown) and a ventilation cover assembly 90. The cover is arranged above the top cover 100 and surrounds the outside of the control rod drive mechanism, and the ventilation cover assembly 90 is arranged above the top cover 100 and surrounds the outside of the cover, and is connected to the cover, thereby communicating with the space inside the cover where the control rod drive mechanism is located.

[0098] When the ventilation cover assembly 90 is working, it can extract the gas in the space where the control rod drive mechanism is located, thereby achieving heat dissipation and reducing the temperature of the space where the control rod drive mechanism is located.

[0099] The above description is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation based on the content of the specification and drawings, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A dual-cable bridge-type reactor head structure, characterized by, The hanging assembly is arranged above the top cover of the pressure vessel and at the periphery of the control rod drive mechanism, the anti-seismic assembly is arranged above the top cover and below the support frame, the first cable bridge is arranged on one side of the reactor pool top platform, and the second cable bridge is arranged on the other side of the reactor pool top platform. The hanging assembly comprises a plurality of hangers and a support frame, the plurality of hangers are arranged in a circumferential direction of the top cover and vertically connected to the top cover, and the support frame is connected to the top of the plurality of hangers. The anti-seismic assembly is arranged above the top cover and below the support frame. The first cable bridge and the second cable bridge are symmetrically arranged on both sides of the reactor center and reversibly connected to the anti-seismic assembly. When the reactor is in operation, the first cable bridge and the second cable bridge are in a flat state and are arranged on the top platform of the reactor pool.

2. The dual-cable bridge reactor head structure of claim 1, wherein, When the reactor is in shutdown and refueling, the first cable bridge and the second cable bridge are in a vertical state. When the first cable bridge and the second cable bridge are in the flat state, the included angle with the horizontal plane is -20°-40°.

3. The dual-cable bridge reactor head structure of claim 1, wherein, When the first cable bridge and the second cable bridge are in the vertical state, the included angle with the vertical plane is -20°-40°.

4. The dual-cable bridge reactor head structure of claim 1, wherein, The horizontal distance between the center line of the first cable bridge and the center line of the second cable bridge is 0-1000mm.

5. The dual-cable bridge reactor head structure of claim 1, wherein, The hanging assembly comprises four hangers, and the support frame is a cross-shaped support frame or an I-shaped support frame. The double-cable bridge type reactor top structure further comprises at least one first anti-seismic supporting assembly and at least one second anti-seismic supporting assembly. The first anti-seismic supporting assembly is arranged between the first cable bridge and the top platform of the reactor pool and connects the first cable bridge in the flat state to the top platform of the reactor pool.

6. The dual-cable bridge reactor head structure of claim 5, wherein, The second anti-seismic supporting assembly is arranged between the second cable bridge and the top platform of the reactor pool and connects the second cable bridge in the flat state to the top platform of the reactor pool. The first anti-seismic supporting assembly comprises a perforated plate arranged on one side of the first cable bridge facing the top platform of the reactor pool, a connecting seat fixed on the top platform of the reactor pool, and connecting bolts.

7. The dual-cable bridge reactor head structure of claim 1, wherein, When the first cable bridge is flat, the perforated plate is fitted to the connecting seat, and the connecting bolts are arranged on the connecting seat and the perforated plate to connect the perforated plate to the connecting seat. The length of the first cable bridge is 2000mm-8000mm, and the width is 500mm-2000mm.

8. The dual-cable bridge reactor head structure of claim 1, wherein, The length of the second cable bridge is 2000mm-8000mm, and the width is 500mm-2000mm. The first cable bridge comprises at least one first bridge layer, the first bridge layer comprises a first bridge and at least one first partition plate, one end of the first bridge is connected to the anti-seismic assembly through a first supporting assembly, the opposite end of the first bridge is provided with a first arc-shaped plate, and the first partition plate is arranged on the first bridge and extends along the length direction of the first bridge to divide the space on the first bridge into at least two columns of channels for laying cables. The second cable bridge includes at least one second bridge layer; the second bridge layer includes a second bridge and at least one second partition plate; one end of the second bridge is connected to the anti-seismic assembly through a second support assembly, and the other end of the second bridge is provided with a second arc-shaped plate; the second partition plate is arranged on the second bridge and extends along the length direction of the second bridge, so as to divide the space on the second bridge into at least two columns of channels for laying cables.

9. The dual-cable bridge reactor head structure of claim 8, wherein, The first cable bridge further includes first protective railings arranged on at least two sides of the first bridge. The second cable bridge further includes second protective railings arranged on at least two sides of the second bridge.

10. The dual-cable bridge reactor head structure of claim 1, wherein, The hanging assembly further includes a hook unit connected to the center of the support frame and a working platform arranged on the support frame and located outside the hook unit.

11. The dual-cable bridge reactor head structure of claim 1, wherein, The anti-seismic assembly includes an anti-seismic ring; each of the hanging rods of the hanging assembly vertically passes through the anti-seismic ring and is connected to the top cover.

12. The dual-cable bridge reactor head structure of claim 11, wherein, The anti-seismic assembly further includes at least one anti-seismic pull rod; one end of the anti-seismic pull rod is connected to the anti-seismic ring, and the other end is connected to the wall surface of the reactor pool.

13. The dual-cable bridge reactor head structure of any of claims 1-12, wherein, The double-cable-bridge type reactor head structure further includes a cable bracket unit connected to the anti-seismic assembly and located at the top of the control rod drive mechanism. The first cable bridge is provided with a first connecting frame, and the second cable bridge is provided with a second connecting frame. In the vertical state of the first cable bridge, the end of the first connecting frame is connected to the cable bracket unit. In the vertical state of the second cable bridge, the end of the second connecting frame is connected to the cable bracket unit.

14. The dual-cable bridge reactor head structure of claim 13, wherein, The double-cable-bridge type reactor head structure further includes a cable grid; the cable grid is arranged on the top cover and below the anti-seismic assembly.

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