A reactor coolant loop and its installation method

Abstract

The present invention provides a reactor coolant loop and its installation method, including: a reactor pressure vessel, an attached main pump steam generator, a hot section main pipeline, and a cold section main pipeline; since the perpendicular line of the docking surface between the hot section main pipeline and the reactor pressure vessel is parallel to the perpendicular line of the docking surface between the cold section main pipeline and the reactor pressure vessel, and the perpendicular line of the docking surface between the steam generator and the cold section main pipeline is perpendicular to the perpendicular line of the docking surface between the reactor pressure vessel and the cold section main pipeline, the loop from the coolant outlet nozzle of the reactor pressure vessel to the coolant inlet nozzle of the reactor pressure vessel after improvement is in a portal structure, with simple groove alignment. Each component of the loop can freely contract during alignment welding, thereby reducing the welding restraint and welding stress of the loop structure. At the same time, the number of installation welds and welding positions of the loop are reduced, which is beneficial to cost reduction and efficiency improvement, and improves the safety and economy of nuclear power plant construction and operation.

Description

Technical Field

[0001] The present invention belongs to the field of pressurized water reactor nuclear power plant construction, and particularly relates to a reactor coolant loop and an installation method thereof. Background Art

[0002] At present, the design of the reactor coolant loop of domestic pressurized water reactor nuclear power plants mainly has the "1 hot leg - 1 transition section - 1 cold leg" mode of the M310 type and the "1 hot leg - 2 cold legs" mode of the AP1000 type. As Figure 1 shown, the structure of the reactor coolant loop of the AP1000 type is relatively compact because the main pump is attached to the steam generator and the transition section is omitted. However, the disadvantage is that since 3 welding grooves need to be butt-welded simultaneously between the bottom head nozzle and the pump casing nozzle of the steam generator and the main pipeline during installation, the butt-welding groove alignment of the main pipeline is complex, difficult, and has a high risk. The circumferential welding restraint of the loop is large, resulting in a high risk of welding stress and welding deformation; and there are a total of 6 installation welds in one loop, 12 installation welds in 2 loops of a million-kilowatt unit, and 2 welding positions of 5GT and 6GT, resulting in a large amount of work in welding preparation, welding process qualification, welding, and non-destructive inspection of the main pipeline, and a long installation and welding period. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a reactor coolant loop that reduces the difficulty of groove alignment, the number of welds and welding positions, and reduces the circumferential welding restraint and welding stress of the loop structure in view of the above deficiencies in the prior art.

[0004] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0005] The present invention provides a reactor coolant loop, including: a reactor pressure vessel, a steam generator with an attached main pump, a hot leg main pipeline, and a cold leg main pipeline;

[0006] The hot leg main pipeline is welded horizontally and fixedly between the reactor pressure vessel and the steam generator by butt-welding of pipes;

[0007] The cold leg main pipeline is welded horizontally and fixedly between the reactor pressure vessel and the steam generator by butt-welding of pipes;

[0008] The perpendicular line of the butt-joint surface between the hot leg main pipeline and the reactor pressure vessel is parallel to the perpendicular line of the butt-joint surface between the cold leg main pipeline and the reactor pressure vessel;

[0009] The perpendicular line of the butt-joint surface between the cold leg main pipeline and the steam generator is perpendicular to the perpendicular line of the butt-joint surface between the cold leg main pipeline and the reactor pressure vessel.

[0010] Optionally, the bottom head of the steam generator is provided with a hot-end pump casing and a cold-end pump casing;

[0011] The nozzle of the hot-end pump housing is connected to the main hot-section pipeline, and the lower end of the hot-end pump housing is connected to the main hot-end pump motor;

[0012] The nozzle of the cold-end pump housing is connected to the main cold-section pipeline, and the lower end of the cold-end pump housing is connected to the main cold-end pump motor; or,

[0013] The bottom head of the steam generator is provided with a hot-end elbow and a cold-end pump housing;

[0014] The nozzle of the hot-end elbow is connected to the main hot-section pipeline;

[0015] The nozzle of the cold-end pump housing is connected to the main cold-section pipeline, and the lower end of the cold-end pump housing is connected to the main cold-end pump motor.

[0016] Optionally, the main cold-section pipeline is an L-shaped pipe, which includes a short section and a long section after continuous bending. The end of the short section is connected to the nozzle end of the cold-end pump housing, and the end of the long section is connected to the coolant inlet nozzle end of the reactor pressure vessel. The plane of the pump housing end of the main cold-section pipeline is perpendicular to the plane of the reactor pressure vessel end.

[0017] Optionally, both the long section of the main cold-section pipeline and the main hot-section pipeline are straight pipes, and the long section of the main cold-section pipeline is parallel to the main hot-section pipeline.

[0018] Optionally, the reactor pressure vessel is provided with a coolant inlet nozzle and a coolant outlet nozzle, and the nozzle end planes of the coolant inlet nozzle and the coolant outlet nozzle are parallel.

[0019] Optionally, one end of the main hot-section pipeline and both ends of the main cold-section pipeline are provided with adjustment sections.

[0020] Optionally, both the nozzle end of the hot-end pump housing of the steam generator and the nozzle end of the cold-end pump housing are provided with adjustment sections, or,

[0021] Both the nozzle end of the hot-end elbow of the steam generator and the nozzle end of the cold-end pump housing are provided with adjustment sections.

[0022] An installation method for a reactor coolant loop with an adjustment section on the main cold-section pipeline as described above. Let the welds between the steam generator and the main hot-section pipeline, between the steam generator and the main cold-section pipeline, between the reactor pressure vessel and the main hot-section pipeline, and between the reactor pressure vessel and the main cold-section pipeline be the first weld, the second weld, the third weld, and the fourth weld respectively;

[0023] The installation method includes:

[0024] Pair and weld the nozzle plane of the hot-end pump housing of the steam generator or the nozzle plane of the hot-end elbow and the pump housing end plane of the main hot-section pipeline to form the first weld;

[0025] The end plane of the hot section main pipe is assembled and fixed with the nozzle plane of the coolant outlet nozzle of the reactor pressure vessel;

[0026] Taking the end of the coolant inlet nozzle of the reactor pressure vessel and the end of the cold end pump housing nozzle of the steam generator as the reference, measure and machine the adjustment sections at both ends of the cold section main pipe, and after the pipe ends of the cold section main pipe are assembled with the cold end pump housing nozzle end of the steam generator, the pipe ends of the cold section main pipe are staggered from the end of the coolant inlet nozzle of the reactor pressure vessel by the shrinkage amount of a second weld;

[0027] The pipe end of the cold section main pipe is welded to the cold end pump housing nozzle end of the steam generator to form a second weld. The shrinkage of the second weld drives the other end of the cold section main pipe to move and align with the end of the coolant inlet nozzle of the reactor pressure vessel;

[0028] The pipe end of the hot section main pipe and the pipe end of the cold section main pipe are respectively welded to the coolant outlet nozzle end and the coolant inlet nozzle end of the reactor pressure vessel to form a third weld and a fourth weld, completing the installation of a reactor coolant loop.

[0029] Another installation method of a reactor coolant loop with an adjustment section at the nozzle end of the steam generator pump housing as described above. Let the welds between the steam generator and the hot section main pipe, between the steam generator and the cold section main pipe, between the reactor pressure vessel and the hot section main pipe, and between the reactor pressure vessel and the cold section main pipe be the first weld, the second weld, the third weld, and the fourth weld respectively;

[0030] The installation method includes:

[0031] The hot section main pipe and the cold section main pipe are respectively assembled and fixed with the coolant outlet nozzle end and the coolant inlet nozzle end of the reactor pressure vessel, and the pipe end of the cold section main pipe is staggered from the end of the coolant inlet nozzle of the reactor pressure vessel by the shrinkage amount of a second weld;

[0032] Taking the steam generator end of the hot section main pipe and the steam generator end of the cold section main pipe as the reference, measure and machine the adjustment section of the hot end pump housing or the hot end elbow nozzle end of the steam generator and the adjustment section of the cold end pump housing nozzle end of the steam generator, and after the steam generator is assembled with the hot section main pipe, the cold end pump housing nozzle end of the steam generator is staggered from the pipe end of the cold section main pipe by the shrinkage amount of a first weld;

[0033] Release the assembly and fixation of the hot section main pipe and the coolant outlet nozzle end of the reactor pressure vessel;

[0034] The nozzle end of the hot end pump housing or the hot end elbow of the steam generator is welded to the pipe end of the hot section main pipe to form a first weld;

[0035] After the first weld seam shrinks, the pipe end of the hot section main pipe is fixed in alignment with the coolant outlet nozzle end of the reactor pressure vessel, while the nozzle end of the cold end pump housing of the steam generator is aligned and paired with the pipe end of the cold section main pipe;

[0036] Release the pairing and fixation of the pipe end of the cold section main pipe and the coolant inlet nozzle end of the reactor pressure vessel;

[0037] The pipe end of the cold section main pipe is welded to the nozzle end of the cold end pump housing of the steam generator to form a second weld seam. The shrinkage of the second weld seam drives the movement of the pipe end of the cold section main pipe to align and pair with the coolant inlet nozzle end of the reactor pressure vessel;

[0038] The pipe end of the hot section main pipe and the pipe end of the cold section main pipe are respectively welded to the coolant outlet nozzle end and the coolant inlet nozzle end of the reactor pressure vessel to form a third weld seam and a fourth weld seam, completing the installation of a reactor coolant loop.

[0039] In the present invention, by redesigning the AP1000 reactor coolant loop, compared with the original AP1000 design, since the perpendicular line of the docking surface between the hot section main pipe and the reactor pressure vessel is parallel to the perpendicular line of the docking surface between the cold section main pipe and the reactor pressure vessel, and the perpendicular line of the docking surface between the cold section main pipe and the steam generator is perpendicular to the perpendicular line of the docking surface between the cold section main pipe and the reactor pressure vessel, the loop from the coolant outlet nozzle of the reactor pressure vessel to the coolant inlet nozzle of the reactor pressure vessel after improvement has a portal structure, the groove alignment is simple, and each component of the loop can freely contract during alignment and welding, reducing the restraint degree and welding stress during the alignment and welding of the loop structure. In addition, the "1 hot section - 2 cold sections" structure of the original AP1000 design is simplified to a "1 hot section - 1 cold section" structure. The number of main pipe installation weld seams in one loop is reduced from 6 to 4, and the number of main pipe installation weld seams in two loops can be reduced from 12 to 8. The two welding positions of 5GT and 6GT in the original AP1000 design are reduced to one welding position of 5GT, correspondingly greatly reducing the construction workload, which is beneficial to reducing costs, shortening the construction period, and improving the safety and economy of nuclear power plant construction and operation. Brief Description of the Drawings

[0040] Figure 1 It is a schematic structural diagram of the original AP1000 reactor coolant loop;

[0041] Figure 2 It is a schematic structural diagram of the reactor coolant loop provided by the present invention;

[0042] Figure 3 It is a bottom view schematic diagram of the reactor pressure vessel in the present invention;

[0043] Figure 4 It is a bottom view schematic diagram of the steam generator in Embodiment 1;

[0044] Figure 5 It is a schematic side view of the steam generator in Embodiment 1;

[0045] Figure 6 It is a schematic bottom view of the steam generator in Embodiment 2;

[0046] Figure 7 It is a schematic side view of the steam generator in Embodiment 2;

[0047] Figure 8 It is a schematic bottom view of the hot end pump housing or the hot end elbow in the present invention;

[0048] Figure 9 It is a schematic bottom view of the cold end pump housing in the present invention.

[0049] In the figure: 1 - steam generator (only the tube sheet and the lower head are shown, and the rest are omitted); 2 - hot end main pump motor; 3 - hot end pump housing; 3a - hot end elbow; 4 - hot end pump housing nozzle plane or hot end elbow nozzle plane; 5 - hot section main pipeline pump housing end plane; 6 - hot section main pipeline; 7 - hot section main pipeline reactor pressure vessel end plane; 8 - reactor pressure vessel outlet nozzle end plane; 9 - reactor pressure vessel outlet nozzle; 10 - reactor pressure vessel; 11 - cold end main pump motor; 12 - cold end pump housing nozzle end plane; 13 - cold section main pipeline pump housing end plane; 14 - cold end pump housing; 15 - cold section main pipeline; 16 - cold section main pipeline reactor pressure vessel end plane; 17 - reactor pressure vessel inlet nozzle end plane; 18 - reactor pressure vessel inlet nozzle; 19 - cold end pump housing nozzle axis. Detailed implementation manners

[0050] Next, the technical solutions in the present invention will be clearly and completely described in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the scope of the present invention.

[0051] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "upper" is based on the orientation or positional relationship shown in the accompanying drawings. It is only for convenience and simplification of description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0052] In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0053] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connection", "installation", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] Embodiment 1:

[0055] As Figure 2 shown, this embodiment provides a reactor coolant loop, including: a reactor pressure vessel 10, a steam generator 1, a hot leg main pipe 6, and a cold leg main pipe 15;

[0056] The hot leg main pipe 6 adopts the 5GT welding position, that is, the pipe butt joint is horizontally fixed and welded between the reactor pressure vessel 10 and the steam generator 1;

[0057] The cold leg main pipe 15 adopts the 5GT welding position, that is, the pipe butt joint is horizontally fixed and welded between the reactor pressure vessel 10 and the steam generator 1;

[0058] When the hot leg main pipe 6 is butted with the nozzle end plane 8 of the coolant outlet nozzle 9 of the reactor pressure vessel 10, the perpendicular line of the pipe end face 7 is parallel to the perpendicular line of the pipe end face 16 when the cold leg main pipe 15 is butted with the nozzle end plane 17 of the coolant inlet nozzle 18 of the reactor pressure vessel 10;

[0059] As Figure 2 、 Figure 9 shown, the perpendicular line 19 of the cold end pump casing nozzle end plane 12 where the steam generator 1 is butted with the pipe end face 13 of the cold leg main pipe 15 is perpendicular to the perpendicular line of the nozzle end plane 17 of the coolant inlet nozzle 18 where the reactor pressure vessel 10 is butted with the pipe end face 16 of the cold leg main pipe 15.

[0060] In this embodiment, as Figure 2 、 Figure 4 、 Figure 5 、 Figure 8 and Figure 9 shown, the bottom head of the steam generator 1 is provided with a hot end pump casing 3 and a cold end pump casing 14;

[0061] The nozzle 4 of the hot end pump casing 3 is connected to the pump casing end 5 of the hot leg main pipe 6, and the lower end of the hot end pump casing 3 is connected to the hot end main pump motor 2;

[0062] The nozzle end 12 of the cold end pump casing 14 is connected to the pump casing end 13 of the cold leg main pipe 15, and the lower end of the cold end pump casing 14 is connected to the cold end main pump motor 11.

[0063] In this embodiment, asFigure 2 As shown, the cold leg main pipe 15 is an L-shaped pipe, which includes a short section and a long section after continuous bending. The pipe end 13 of the short section is connected to the nozzle end 12 of the cold end pump casing 14, and the pipe end 16 of the long section is connected to the coolant inlet nozzle end 17 of the reactor pressure vessel 10. The pump casing end plane 13 of the cold leg main pipe 15 is perpendicular to the reactor pressure vessel end plane 16.

[0064] In this embodiment, as Figure 3 shown, the reactor pressure vessel 10 is provided with a coolant outlet nozzle 9 and a coolant inlet nozzle 18. The nozzle end plane 8 of the coolant outlet nozzle 9 and the nozzle end plane 17 of the coolant inlet nozzle 18 are parallel.

[0065] In this embodiment, as Figure 2 shown, when the distance between the coolant outlet nozzle 9 and the coolant inlet nozzle 18 of the reactor pressure vessel 10 matches the distance between the hot end pump casing nozzle or the hot end elbow nozzle of the steam generator 1 and the cold end pump casing nozzle, the hot leg main pipe 6 can adopt a straight pipe, and the long straight section of the cold leg main pipe 15 can be parallel to the hot leg main pipe 6. The beneficial effect is that the elbow pipe cost can be saved; conversely, if the distance between the coolant outlet nozzle 9 and the coolant inlet nozzle 18 of the reactor pressure vessel 10 does not match the distance between the hot end pump casing nozzle or the hot end elbow nozzle of the steam generator 1 and the cold end pump casing nozzle, the hot leg main pipe 6 and the long section of the cold leg main pipe 15 can adopt elbow pipes.

[0066] In this embodiment, as Figure 2 shown, one end 5 or 7 of the hot leg main pipe 6 and both ends 13 and 16 of the cold leg main pipe 15 are provided with adjustment sections.

[0067] As Figure 2 shown, let the welds between the steam generator 1 and the hot leg main pipe 6 at 4-5, between the steam generator 1 and the cold leg main pipe 15 at 12-13, between the reactor pressure vessel 10 and the hot leg main pipe 6 at 7-8, and between the reactor pressure vessel 10 and the cold leg main pipe 15 at 16-17 be the first weld, the second weld, the third weld, and the fourth weld respectively. The installation method of the reactor coolant loop in this embodiment includes:

[0068] Align and weld the hot end pump casing nozzle plane or the hot end elbow nozzle plane 4 of the steam generator 1 and the pump casing end plane 5 of the hot leg main pipe 6 to form the first weld;

[0069] Fix the end plane 7 of the hot leg main pipe 6 and the nozzle plane 8 of the coolant outlet nozzle 9 of the reactor pressure vessel 10 in alignment;

[0070] Taking the coolant inlet nozzle end 17 of the reactor pressure vessel 10 and the cold-end pump casing nozzle end 12 of the steam generator 1 as a reference, measure the adjustment sections at both ends 13 and 16 of the cold leg main pipe 15, and after the pipe end 13 of the cold leg main pipe 15 is paired with the cold-end pump casing nozzle end 12 of the cold-end pump casing 14 of the steam generator, the pipe end 16 of the cold leg main pipe 15 is offset from the coolant inlet nozzle end 17 of the reactor pressure vessel 10 by the shrinkage amount of a second weld;

[0071] The pipe end 13 of the cold leg main pipe 15 is welded to the cold-end pump casing nozzle end 12 of the cold-end pump casing 14 of the steam generator 1 to form a second weld. The shrinkage of the second weld along the welding direction 19 drives the other end 16 of the cold leg main pipe 15 to move and align with the coolant inlet nozzle end 17 of the reactor pressure vessel 10 for pairing;

[0072] The pipe end 7 of the hot leg main pipe 6 and the pipe end 16 of the cold leg main pipe 15 are respectively welded to the coolant outlet nozzle end 8 and the coolant inlet nozzle end 17 of the reactor pressure vessel 10 to form a third weld and a fourth weld, completing the installation of a reactor coolant loop.

[0073] Embodiment 2:

[0074] This embodiment provides a reactor coolant loop, whose structure is substantially the same as that of Embodiment 1. The difference is that the nozzle ends 4 of the hot-end pump casing 3 and 12 of the cold-end pump casing 14 of the steam generator are both provided with adjustment sections, while the hot leg main pipe 6 and the cold leg main pipe 15 are not provided with adjustment sections.

[0075] As Figure 2 shown, let the welds between the steam generator 1 and the hot leg main pipe 6 at 4-5, between the steam generator 1 and the cold leg main pipe 15 at 12-13, between the reactor pressure vessel 10 and the hot leg main pipe 6 at 7-8, and between the reactor pressure vessel 10 and the cold leg main pipe 15 at 16-17 be the first weld, the second weld, the third weld, and the fourth weld respectively. The installation method of the reactor coolant loop in this embodiment includes:

[0076] As Figure 2 shown, the hot leg main pipe 6 and the cold leg main pipe 15 are respectively paired and fixed with the coolant outlet nozzle end 8 and the coolant inlet nozzle end 17 of the reactor pressure vessel 10, and the pipe end 16 of the cold leg main pipe is offset from the coolant inlet nozzle end 17 of the reactor pressure vessel by the shrinkage amount of a second weld;

[0077] Taking the steam generator end 5 of the hot section main pipe 6 and the steam generator end 13 of the cold section main pipe 15 as references, measure the adjustment sections of the nozzle end 4 of the hot end pump casing or the hot end elbow pipe of the steam generator 1 and the adjustment section of the nozzle end 12 of the cold end pump casing of the steam generator 1. After the steam generator 1 is paired with the hot section main pipe 6, the nozzle end 12 of the cold end pump casing of the steam generator is staggered from the pipe end 13 of the cold section main pipe by the shrinkage amount of a first weld;

[0078] Release the pairing and fixing of the pipe end 7 of the hot section main pipe 6 and the coolant outlet nozzle end 8 of the reactor pressure vessel 10;

[0079] Weld the nozzle end 4 of the hot end pump casing or the hot end elbow of the steam generator 1 and the pipe end 5 of the hot section main pipe 6 to form a first weld;

[0080] After the first weld shrinks, pair and fix the pipe end 7 of the hot section main pipe 6 with the coolant outlet nozzle end 8 of the reactor pressure vessel 10, and align and pair the nozzle end 12 of the cold end pump casing of the steam generator 1 with the pipe end 13 of the cold section main pipe 15;

[0081] Release the pairing and fixing of the pipe end 16 of the cold section main pipe 15 and the coolant inlet nozzle end 17 of the reactor pressure vessel 10;

[0082] Weld the pipe end 13 of the cold section main pipe 15 and the nozzle end 12 of the cold end pump casing of the steam generator 1 to form a second weld. The shrinkage of the second weld along the direction 19 drives the pipe end 16 of the cold section main pipe 15 to move and align and pair with the coolant inlet nozzle end 17 of the reactor pressure vessel 10;

[0083] Weld the pipe end 7 of the hot section main pipe 6 and the pipe end 16 of the cold section main pipe 15 to the coolant outlet nozzle end 8 and the coolant inlet nozzle end 17 of the reactor pressure vessel 10 respectively to form a third weld and a fourth weld, completing the installation of a reactor coolant loop.

[0084] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present invention. However, the present invention is not limited thereto. For those of ordinary skill in the art, various variations and improvements can be made without departing from the spirit and essence of the present invention, and these variations and improvements are also regarded as the protection scope of the present invention.

Claims

1. A reactor coolant loop, characterized in that, Including: A reactor pressure vessel (10), a steam generator (1), a hot leg main pipe (6) and a cold leg main pipe (15); The hot leg main pipe (6) is horizontally fixed welded by butt welding between the reactor pressure vessel (10) and the steam generator (1); The cold leg main pipe (15) is horizontally fixed welded by butt welding between the reactor pressure vessel (10) and the steam generator (1); The perpendicular line of the end plane (7) where the hot leg main pipe (6) is butt - jointed with the reactor pressure vessel (10) is parallel to the perpendicular line of the end plane (16) where the cold leg main pipe (15) is butt - jointed with the reactor pressure vessel (10); The perpendicular line of the end plane (12) where the steam generator (1) is butt - jointed with the cold leg main pipe (15) is perpendicular to the perpendicular line of the end plane (17) where the reactor pressure vessel (10) is butt - jointed with the cold leg main pipe (15); The bottom head of the steam generator (1) is provided with a hot end pump casing (3) and a cold end pump casing (14); The nozzle of the hot end pump casing (3) is connected to the hot leg main pipe (6), and the lower end of the hot end pump casing (3) is connected to the hot end main pump motor (2); The nozzle of the cold end pump casing (14) is connected to the cold leg main pipe (15), and the lower end of the cold end pump casing (14) is connected to the cold end main pump motor (11); or, The bottom head of the steam generator (1) is provided with a hot end elbow (3a) and a cold end pump casing (14); The nozzle of the hot end elbow (3a) is connected to the hot leg main pipe (6), The nozzle of the cold end pump casing (14) is connected to the cold leg main pipe (15), and the lower end of the cold end pump casing (14) is connected to the cold end main pump motor (11).

2. The reactor coolant loop according to claim 1, characterized in that, The pump casing end plane (13) of the cold leg main pipe (15) is perpendicular to the reactor pressure vessel end plane (16).

3. The reactor coolant loop according to claim 1, characterized in that, The reactor pressure vessel (10) is provided with a coolant inlet nozzle (18) and a coolant outlet nozzle (9), and the nozzle end plane (17) of the coolant inlet nozzle (18) is parallel to the nozzle end plane (8) of the coolant outlet nozzle (9).

4. The reactor coolant loop according to any one of claims 1-3, characterized in that, One end of the hot leg main pipe (6) and both ends of the cold leg main pipe (15) are provided with adjustment sections.

5. The reactor coolant loop according to any one of claims 1-3, characterized in that, The nozzle ends of the hot end pump casing (3) and the cold end pump casing (14) are both provided with adjustment sections, or, The nozzle ends of the hot end elbow (3a) and the nozzle end of the cold end pump casing (14) are both provided with adjustment sections.

6. An installation method of a reactor coolant loop as described in claim 4, where the welds between the steam generator (1) and the hot leg main pipe (6), between the steam generator (1) and the cold leg main pipe (15), between the reactor pressure vessel (10) and the hot leg main pipe (6), and between the reactor pressure vessel (10) and the cold leg main pipe (15) are respectively the first weld, the second weld, the third weld and the fourth weld; The installation method includes: Pairing and welding the hot end pump casing nozzle plane or the hot end elbow nozzle plane (4) of the steam generator (1) and the pump casing end plane (5) of the hot leg main pipe (6) to form the first weld; The end plane (7) of the hot leg main pipe (6) is assembled and fixed with the nozzle plane (8) of the coolant outlet nozzle (9) of the reactor pressure vessel; Taking the end (17) of the coolant inlet nozzle of the reactor pressure vessel and the end (12) of the cold end pump housing nozzle of the steam generator as the reference, measure and machine the adjustment sections at both ends (13) and (16) of the cold leg main pipe (15), and after the pipe end (13) of the cold leg main pipe (15) is assembled with the cold end pump housing nozzle end (12) of the steam generator cold end pump housing (14), the pipe end (16) of the cold leg main pipe (15) is offset from the coolant inlet nozzle end (17) of the reactor pressure vessel by the shrinkage amount of a second weld; The pipe end (13) of the cold leg main pipe (15) is welded to the cold end pump housing nozzle end (12) of the steam generator cold end pump housing (14) to form a second weld. The shrinkage of the second weld drives the other end (16) of the cold leg main pipe (15) to move and align with the coolant inlet nozzle end (17) of the reactor pressure vessel; The pipe end (7) of the hot leg main pipe (6) and the pipe end (16) of the cold leg main pipe (15) are respectively welded to the coolant outlet nozzle end (8) and the coolant inlet nozzle end (17) of the reactor pressure vessel to form a third weld and a fourth weld, completing the installation of a reactor coolant loop.

7. An installation method of a reactor coolant loop as described in claim 5, where the welds between the steam generator (1) and the hot leg main pipe (6), between the steam generator (1) and the cold leg main pipe (15), between the reactor pressure vessel (10) and the hot leg main pipe (6), and between the reactor pressure vessel (10) and the cold leg main pipe (15) are respectively the first weld, the second weld, the third weld, and the fourth weld; The installation method includes: The hot leg main pipe (6) and the cold leg main pipe (15) are respectively assembled and fixed with the coolant outlet nozzle end (8) and the coolant inlet nozzle end (17) of the reactor pressure vessel (10), and the pipe end (16) of the cold leg main pipe is offset from the coolant inlet nozzle end (17) of the reactor pressure vessel by the shrinkage amount of a second weld; Taking the steam generator end (5) of the hot leg main pipe and the steam generator end (13) of the cold leg main pipe as the reference, measure and machine the adjustment sections of the hot end pump housing or the hot end elbow nozzle end (4) of the steam generator (1) and the adjustment section of the cold end pump housing nozzle end (12) of the steam generator (1), and after the steam generator (1) is assembled with the hot leg main pipe (6), the cold end pump housing nozzle end (12) of the steam generator is offset from the pipe end (13) of the cold leg main pipe by the shrinkage amount of a first weld; Release the assembly and fixation of the hot leg main pipe (6) and the coolant outlet nozzle end (8) of the reactor pressure vessel (10); The nozzle end (4) of the hot end pump housing or the hot end elbow of the steam generator (1) and the pipe end (5) of the hot leg main pipe (6) are welded to form a first weld; After the shrinkage of the first weld, the pipe end (7) of the hot section main pipe (6) is assembled and fixed with the coolant outlet nozzle end (8) of the reactor pressure vessel (10), while the cold end pump casing nozzle end (12) of the steam generator (1) is aligned and assembled with the pipe end (13) of the cold section main pipe (15); The assembly and fixation of the pipe end (16) of the cold section main pipe (15) and the coolant inlet nozzle end (17) of the reactor pressure vessel (10) are released; The pipe end (13) of the cold section main pipe (15) is welded to the nozzle end (12) of the cold end pump casing of the steam generator (1) to form a second weld. The shrinkage of the second weld drives the pipe end (16) of the cold section main pipe (15) to move and align with the coolant inlet nozzle end (17) of the reactor pressure vessel (10) for assembly; The pipe end (7) of the hot section main pipe (6) and the pipe end (16) of the cold section main pipe (15) are respectively welded to the coolant outlet nozzle end (8) and the coolant inlet nozzle end (17) of the reactor pressure vessel (10) to form a third weld and a fourth weld, completing the installation of a reactor coolant loop.

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