CN113782237A - Maintenance method for reactor core measurement system sealing section - Google Patents
Maintenance method for reactor core measurement system sealing section Download PDFInfo
- Publication number
- CN113782237A CN113782237A CN202110888843.XA CN202110888843A CN113782237A CN 113782237 A CN113782237 A CN 113782237A CN 202110888843 A CN202110888843 A CN 202110888843A CN 113782237 A CN113782237 A CN 113782237A
- Authority
- CN
- China
- Prior art keywords
- section
- seal
- sub
- passage
- pressure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000007789 sealing Methods 0.000 title claims abstract description 137
- 238000012423 maintenance Methods 0.000 title claims abstract description 43
- 238000005259 measurement Methods 0.000 title claims abstract description 35
- 238000000034 method Methods 0.000 title claims abstract description 34
- 230000000903 blocking effect Effects 0.000 claims abstract description 22
- 238000012360 testing method Methods 0.000 claims description 18
- 238000002955 isolation Methods 0.000 claims description 15
- 230000035515 penetration Effects 0.000 claims description 13
- 239000000446 fuel Substances 0.000 claims description 6
- 230000000149 penetrating effect Effects 0.000 claims description 5
- 238000004891 communication Methods 0.000 claims description 3
- 238000010276 construction Methods 0.000 abstract description 8
- 230000007547 defect Effects 0.000 abstract description 5
- 238000011144 upstream manufacturing Methods 0.000 description 8
- 239000007788 liquid Substances 0.000 description 6
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- 230000000712 assembly Effects 0.000 description 3
- 238000000429 assembly Methods 0.000 description 3
- 239000003758 nuclear fuel Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 235000011089 carbon dioxide Nutrition 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000002950 deficient Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012856 packing Methods 0.000 description 2
- 230000001174 ascending effect Effects 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 210000004907 gland Anatomy 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C17/00—Monitoring; Testing ; Maintaining
- G21C17/017—Inspection or maintenance of pipe-lines or tubes in nuclear installations
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Abstract
The application relates to a maintenance method for a reactor core measurement system seal section, which comprises the following steps: reducing the pressure in the main passage and partially drawing out the finger sleeve; ice blocking a main passage located between the reactor pressure vessel and the seal section to separate a sub-passage at a side of the main passage adjacent to the seal section; releasing the residual pressure within the sub-passage; disassembling the sealing section; and taking out the first sealing element in the sealing section and carrying out maintenance. According to the maintenance method for the reactor core measurement system seal section, after the pressure in the main channel of the system is partially reduced, ice blocking is carried out on the main channel, the sub-channel is separated from one side, close to the seal section, in the main channel, and independent pressure relief can be carried out on the sub-channel under the working condition that the system keeps under pressure, so that the seal section is maintained. The maintenance of the reactor core measuring system sealing section is realized under the working condition of pressure, the withdrawal depth of the time group state during maintenance is reduced, the operation steps during maintenance are reduced, and the construction period of defect treatment of the sealing section is shortened.
Description
Technical Field
The application relates to the technical field of maintenance of a seal section, in particular to a maintenance method for the seal section of a reactor core measuring system.
Background
In a nuclear power plant unit, a plurality of neutron fluence rate measurement channels in a reactor core measurement system (RIC) are distributed in a plurality of fuel assemblies respectively. In the measuring channel of the fuel assembly, a thimble tube is inserted from the bottom of the core, and a detector is moved inside the thimble tube, thereby measuring the neutron fluence rate point by point over the entire height of the core. Wherein, a loop pressure boundary is formed by the sealing section, static and dynamic sealing is established between the guide tube and the finger sleeve, and leakage is not allowed.
In the related technology, when the seal section of the reactor core measurement system leaks, the unit needs to be cooled by the RRA in a normal shutdown mode and then is withdrawn to an MCS maintenance shutdown mode or an RCD complete unloading mode, namely, the pressure of a primary loop of the unit is reduced to the atmospheric pressure, and all nuclear fuel assemblies are unloaded and then are overhauled, so that the operation is complex and the construction period is long.
Disclosure of Invention
On the basis, the core measurement system sealing section overhauling method is needed to be provided aiming at the problems that the core measurement system sealing section overhauling operation is complex and the construction period is long.
The embodiment of the application provides a maintenance method for a reactor core measurement system sealing section, which comprises the following steps:
reducing the pressure in the main passage and partially drawing out the finger sleeve; the main passage is positioned between the finger sleeve and the guide tube sleeved outside the finger sleeve and is communicated with the reactor pressure vessel;
ice blocking a main passage located between the reactor pressure vessel and the seal section to separate a sub-passage at a side of the main passage adjacent to the seal section; the thimble tube is arranged in a fuel assembly in the reactor pressure vessel in a penetrating way, and the sealing section is positioned at one end of the guide tube, which deviates from the reactor pressure vessel;
releasing the residual pressure within the sub-passage;
disassembling the sealing section;
and taking out the first sealing element in the sealing section and carrying out maintenance.
In one embodiment, the step of ice plugging the primary passageway at a location between the reactor pressure vessel and the seal segment comprises:
ice blocking is carried out on a main passage between a penetrating piece sleeved outside the guide pipe and the isolation valve; the penetration piece is positioned between the reactor pressure vessel and the sealing section, and the isolation valve is positioned between the penetration piece and the sealing section.
In one embodiment, the step of releasing the residual pressure within the sub-passage comprises:
removing a second seal on a back pressure fitting in communication with the sub-passage to relieve residual pressure within the sub-passage; the back pressure joint is located between the isolation valve and the sealing section.
In one embodiment, the step of disassembling the seal segment comprises:
cutting off the thrust section and the extension section connected with the finger sleeve, and removing the sleeve in the sealing section to enable the sub-passage to be communicated with the outside; one end of the finger sleeve pipe, which is away from the reactor pressure vessel, penetrates through the sealing section and is connected with the thrust section and the extension section, and one end of the sleeve pipe is sleeved on the end part of the guide pipe.
In one embodiment, the step of removing and servicing the first seal in the seal section comprises:
the sub-passage is pressurized at the back pressure joint to flush the first seal from the seal section.
In one embodiment, the step of pressurizing the sub-passage by the back pressure joint comprises:
one end of the pressure pipeline is connected with the backpressure connector, the other end of the pressure pipeline is connected with the pressure pump, and the pressure pump is used for pressurizing the inside of the sub-passage.
In one embodiment, after the step of removing the first seal in the seal segment and performing service, the method further comprises the following steps:
and reinstalling the first sealing element and the sleeve, and carrying out a first sealing test on the sealing section.
In one embodiment, after the steps of reinstalling the first seal and the sleeve, performing the first tightness test on the seal segment, and testing the seal segment to be qualified, the method further comprises the following steps:
and (4) reconnecting the thrust section and the extension section with the finger sleeve, removing the ice blockage to reconnect the main passage, restoring the finger sleeve to the original position, then performing the ice blockage again, and performing the second tightness test on the sealing section.
In one embodiment, the step of performing a seal test on the seal segment comprises:
and pressurizing the inner part of the sub-passage at the back pressure joint, and checking whether leakage occurs at the sealing section.
In one embodiment, after the step of performing the second tightness test on the sealing section and passing the test, the method further comprises the following steps:
reinstalling a second seal on the back pressure fitting.
According to the maintenance method for the reactor core measuring system sealing section, after the pressure in the main channel of the system is partially reduced, ice blocking is carried out on the main channel, the sub-channel is separated from one side, close to the sealing section, in the main channel, and independent pressure relief can be carried out on the sub-channel under the working condition that the system keeps under pressure so as to maintain the sealing section. The maintenance of the reactor core measuring system sealing section is realized under the working condition of pressure, the withdrawal depth of the time group state during maintenance is reduced, the operation steps during maintenance are reduced, and the construction period of defect treatment of the sealing section is shortened.
Drawings
FIG. 1 is a sectional view of a core measurement system in a core measurement system seal segment maintenance method according to an embodiment of the present application;
FIG. 2 is an enlarged schematic view at A in FIG. 1;
FIG. 3 is a schematic flow chart of a core measurement system seal segment maintenance method provided by an embodiment of the present application;
FIG. 4 is a schematic flow chart of a core measurement system seal segment maintenance method according to another embodiment of the present application.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and that modifications may be made by one skilled in the art without departing from the spirit and scope of the application and it is therefore not intended to be limited to the specific embodiments disclosed below.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.
Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Fig. 1 is a sectional view of a core measurement system in a core measurement system seal segment maintenance method according to an embodiment of the present application, and fig. 2 is an enlarged schematic view at a in fig. 1.
Referring to fig. 1 to 2, the core measurement system in the maintenance method according to the embodiment of the present invention includes a thimble tube 110, a thrust segment 310, an extension segment 320, and a guide tube 120 and a sealing segment 200 penetrating through the thimble tube 110, wherein one end of the thimble tube 110 penetrates through a lower head 180 of the reactor and penetrates into a fuel assembly 170 of the reactor, the guide tube 120 is sleeved outside a portion of the thimble tube 110 located outside the reactor, and a certain gap is not left between the guide tube 120 and the thimble tube 110. It should be noted that guide tube 120 is not sleeved over the entire thimble tube 110, and the end of thimble tube 110 remote from fuel assembly 170 extends through guide tube 120 and connects with thrust segment 310 and extension segment 320. A sealing section 200 is provided at the interface of the finger sleeve 110 and the guide tube 120 to effect a seal between the finger sleeve 110 and the guide tube 120. Wherein, the sealing section 200 is located at the end of the guide tube 120, and a first sealing element 210 is arranged in a sleeve 220 in the sealing section 200 to realize the sealing function of the sealing section 200. Thus, a complete annular channel, i.e., a main passage 130, is formed in the gap between the guide tube 120 and the finger sleeve 110, the main passage 130 is communicated with the reactor pressure vessel, and a liquid medium is filled in the main passage 130 to realize pressure conduction. Between the reactor lower head 180 and the seal segment 200, the guide tube 120 first passes through a penetration member 140, such as a shield wall, etc., and then the guide tube 120 is sequentially provided with an isolation valve 150 and a back pressure joint 160. A channel communicating with the main passage 130 is provided in the back pressure joint 160, and a second sealing member capable of sealing the channel is further provided on the back pressure joint 160. It should be noted that the first sealing element 210 is a generic term for the components that perform the sealing function in the sealing section 200, and the second sealing element is a generic term for the components that perform the sealing function in the back pressure joint 160, that is, each of the first sealing element 210 and the second sealing element may include one or more sealing components, the types of the sealing components are not limited, and when they include a plurality of sealing components, the sealing components may be the same type or different types, and are not limited herein.
In the related technology, when the seal section of the reactor core measurement system leaks, the unit needs to be cooled by the RRA in a normal shutdown mode and then is withdrawn to an MCS maintenance shutdown mode or an RCD complete unloading mode, namely, the pressure of a primary loop of the unit is reduced to the atmospheric pressure, and all nuclear fuel assemblies are unloaded and then are overhauled, so that the operation is complex and the construction period is long.
FIG. 3 is a schematic flow chart of a core measurement system seal segment maintenance method according to an embodiment of the present application.
In order to at least partially solve the above problem, please refer to fig. 3 in combination with fig. 1 to 2, an embodiment of the present application provides a core measurement system seal segment maintenance method, which includes the following steps:
s102, reducing the pressure in the main passage 130, and partially withdrawing the thimble tube 110 together with the thrust section 310 and the extension section 320. The main passage 130 is located between the thimble tube 110 and the guide tube 120 sleeved outside the thimble tube 110, and the main passage 130 is communicated with the reactor pressure vessel.
When the reactor is in the RRA cooling normal shutdown mode, the loop pressure is 25 bar. For subsequent operations, the pressure in the main passage 130 may be reduced to not higher than 10bar, such as 9bar, 8.5bar, 7bar, etc., by reducing the pressure in the primary circuit appropriately. After loosening the upstream and downstream compression nuts of the seal segment 200, the thimble tube 110, along with the thrust segment 310 and extension segment 320, is withdrawn approximately 50cm for subsequent service operations.
And S104, performing ice blocking on the main passage 130 at a position between the reactor pressure vessel and the seal section 200 to separate a sub-passage 131 at one side close to the seal section 200 in the main passage 130.
More specifically, with the main passage 130 at a location between the penetration 140 and the isolation valve 150 being ice blocked, due to the liquid medium contained within the main passage 130, ice blocking of the main passage 130 at a location between the penetration 140 and the isolation valve 150 may form one pressure boundary of the main passage 130 at that location and another pressure boundary of the main passage 130 at the location of the seal segment 200. The main passageway 130 is divided at the ice blocking location forming a sub-passageway 131 between the blocking location and the seal segment 200. The ice blocking operation can be implemented by using an ice blocking device, and the ice blocking device can comprise a dry ice generator (such as a liquid carbon dioxide bottle), and the dry ice is used for cooling the liquid medium in the annular channel inside the finger sleeve 110 and the guide tube 120 so as to solidify and block the liquid medium. After the ice blockage is finished, the liquid medium is dissolved, and the normal use of the thimble tube 110 is not influenced.
S106, the residual pressure in the sub-passage 131 is released.
After step 104, a pressure boundary of the main passage 130 is formed at the ice blocking location and another pressure boundary of the main passage 130 is formed at the seal segment 200 location, the main passage 130 being partitioned at the ice blocking location forming a sub-passage 131 between the blocking location and the seal segment 200. In this way, it will be possible to depressurize the sub-passage 131 individually for servicing of the seal segment 200 without affecting the system pressure within the reactor. The maintenance of the reactor core measuring system sealing section 200 under the working condition of pressure is realized, the withdrawal depth of the time group state during maintenance is reduced, the operation steps during maintenance are reduced, and the construction period of defect treatment of the sealing section 200 is shortened.
And S108, disassembling the sealing section 200.
In step S106, the residual pressure in the sub-passage 131 is released, i.e., the sub-passage 131 between the ice blocking position and the seal segment 200 has been depressurized, at which point the upstream gland nut may be completely loosened and the seal segment 200 disassembled at normal pressure for service.
And S110, taking out the first sealing element 210 in the sealing section 200 and performing maintenance.
After the sealing section 200 is disassembled, the first sealing element 210 in the sealing section 200 can be taken out, the upstream and downstream sealing surfaces in the sealing section 200, the surface of the finger sleeve 110 and the first sealing element 210 can be inspected, and after the failure point is confirmed, the defective part or component can be repaired or replaced.
According to the maintenance method for the reactor core measurement system sealing section, after the pressure in the main passage 130 of the system is partially reduced, the main passage 130 is blocked by ice, the sub-passage 131 is separated from one side, close to the sealing section 200, in the main passage 130, and the sub-passage 131 can be independently decompressed under the working condition that the system keeps under pressure, so that the sealing section 200 can be maintained. The maintenance of the reactor core measuring system sealing section 200 under the working condition of pressure is realized, the withdrawal depth of the time group state during maintenance is reduced, the operation steps during maintenance are reduced, and the construction period of defect treatment of the sealing section 200 is shortened.
Since the guide tube 120 is sequentially provided with the isolation valve 150 and the back pressure joint 160 after passing through the penetration member 140 between the lower head 180 and the seal segment 200 of the reactor, it is necessary to select a proper position for subsequent operations when ice blocking is performed on the main passage 130. Thus, in some embodiments, step S104 comprises: ice blocks the main passage 130 at a location between the penetration 140 and the isolation valve 150. Wherein the penetration 140 is located between the reactor pressure vessel and the seal segment 200 and the isolation valve 150 is located between the penetration 140 and the back pressure joint 160. As shown in fig. 1 and 2, after ice blocking at a location between the penetration 140 and the isolation valve 150, a sub-passage 131 is formed between the blocked location and the seal segment 200 to facilitate subsequent servicing operations.
As described above, since the back pressure joint 160 is provided with a channel communicating with the main passage 130 therein, and the back pressure joint 160 is further provided with a second sealing member capable of sealing the channel, in some embodiments, the step S106 includes: the second seal on the back pressure fitting 160 in communication with the sub-passage 131 is removed to relieve the residual pressure within the sub-passage 131. Wherein the back pressure joint 160 is located between the isolation valve 150 and the seal segment 200. After the second sealing member of the back pressure joint 160 is removed, the sub-passage 131 is communicated with the outside through the channel of the back pressure joint 160, and the residual pressure in the sub-passage 131 can be released.
To remove the first seal 210 in the seal segment 200, the seal segment 200 needs to be disassembled, specifically, in some embodiments, step S108 includes: the thrust segment 310 and the extension segment 320 connected to the finger cuff 110 are cut off, and the sleeve 220 in the sealing segment 200 is removed to communicate the sub-passage 131 with the outside. Wherein, one end of the finger sleeve 110 facing away from the reactor pressure vessel passes through the sealing section 200 and is connected with the thrust section 310 and the extension section 320, and one end of the sleeve 220 is sleeved on the end of the guide tube 120. As shown in fig. 1, after the thrust section 310 and the extension section 320 connected to the thimble tube 110 are removed, the sleeve 220 of the sealing section 200, which has one end sleeved on the thimble tube 110, is removed, and at this time, the sub-passage 131 is communicated with the outside. The first seal 210 in the seal segment 200 may then be removed from the sleeve 220 for servicing.
In the related art, in order to remove the first sealing member 210 in the sealing section 200, a picking tool is usually used to dig out the first sealing member 210 from the sealing section 200, which is liable to damage the sealing surface of the sealing sleeve 220 and the surface of the thimble tube 110 upstream of the sealing section 200, resulting in irreversible damage to the sealing section 200 and the thimble tube 110, and affecting the service life of the system. To solve the above problem, in some embodiments, step S110 includes: the back pressure fitting 160 pressurizes the sub-passage 131 to flush the first seal 210 out of the seal section 200. Since the sub-passage 131 is connected to the outside through the passage in the back pressure joint 160 after the second seal member on the back pressure joint 160 is removed, the sub-passage 131 can be pressurized by the passage in the back pressure joint 160, and the first seal member 210 in the sealing section 200 is punched out by the pressure. The method adopts a pressurization mode to take out the first sealing element 210, does not need to deeply insert a tool into the sealing section 200, does not damage the sealing surface of the sealing sleeve 220 and the surface of the finger sleeve 110 at the upstream of the sealing section 200, and improves the service life of the sealing section 200 to a certain extent.
On the basis of the above embodiment, the step of pressurizing the sub-passage 131 by the back pressure joint 160 includes: one end of the pressure line 410 is connected to the back pressure joint 160, the other end of the pressure line 410 is connected to the pressure pump 420, and the sub-passage 131 is pressurized by the pressure pump 420. As shown in fig. 1, the pressurizing device 400 is connected to the back pressure joint 160, the pressurizing device 400 includes a pressure pump 420, the pressure pump 420 includes an outlet end and an inlet end, the outlet end is connected to the back pressure joint 160 through a pressure pipeline 410, the inlet end is connected to a water source through an inlet pipe, so that water is input to the inner annular channels of the finger sleeve 110 and the guide tube 120 through the pressure pump 420, the water applies pressure to the tube walls of the finger sleeve 110 and the guide tube 120 in the inner annular channel between the finger sleeve 110 and the guide tube 120, and the magnitude of the applied pressure can be set according to the pressure when the crew set operates. The pressure line 410 is further provided with a pressure gauge for indicating the magnitude of the pressure applied to the inner annular passage, a discharge valve for discharging air, a safety valve, and the like. In addition, the pressure pump 420 may be a hand pump.
FIG. 4 is a schematic flow chart of a core measurement system seal segment maintenance method according to another embodiment of the present application.
Referring to fig. 4 in combination with fig. 1 to 2, in other embodiments, the present application provides a core measurement system seal segment maintenance method, which includes the following steps:
s202, the pressure in the main passage 130 is reduced, and the thimble tube 110, along with the thrust section 310 and the extension section 320, is partially withdrawn.
S204, ice blocking the main passage 130 at a position between the penetration 140 and the isolation valve 150 to separate the sub-passage 131 at a side near the seal segment 200 within the main passage 130.
S206, the residual pressure in the sub-passage 131 is released.
S208, disassembling the sealing section 200.
And S210, taking out the first sealing element 210 in the sealing section 200 and performing maintenance.
S212, the first sealing element 210 and the sleeve 220 are reinstalled, and a first sealing performance test is conducted on the sealing section 200.
After the maintenance of the seal section 200 of the core measurement system is completed and the defective component or assembly is repaired or replaced, the disassembled component needs to be reassembled for subsequent normal operation. Therefore, first, the first seal 210 and the sleeve 220 are reinstalled, and the seal segment 200 is subjected to a first tightness test to ensure that the tightness of the seal segment 200 meets the system operation requirements.
S214, the anti-thrust section 310 and the extension section 320 are reconnected with the finger sleeve 110, the ice blockage is removed to enable the main channel 130 to be communicated again, after the finger sleeve 110, the anti-thrust section 310 and the extension section 320 are restored to the original positions, the upstream nut and the downstream nut are tightened with torque, the ice blockage is carried out again, and the sealing section 200 is subjected to a second sealing test.
After the first tightness test of the sealing section 200 is completed and the sealing performance of the sealing section 200 is ensured to meet the requirements, the anti-thrust section 310 and the extension section 320 removed in step S208 are welded to the thimble tube 110 again, the ice blockage is removed, and the thimble tube 110 is returned, that is, the thimble tube 110 is returned to the position where it should be in the normal working state. Subsequently, ice blocking is performed again at the original ice blocking position, at this time, the sealing section 200 is communicated with the sub-passage 131, and a second sealing test is performed on the sealing section 200, that is, whether the sealing performance in the whole sub-passage 131 meets the operation requirement is tested.
In steps S212 and S214, the sealing section 200 needs to be tested for the first sealing performance and the second sealing performance, respectively, and in some embodiments, the following steps may be adopted to pressurize the sub-passage 131 at the back pressure joint 160 and check whether leakage occurs at the sealing section 200. After the second sealing element on the back pressure joint 160 is removed, the sub-passage 131 is communicated with the outside through the channel in the back pressure joint 160, at this time, the channel in the back pressure joint 160 can be used for pressurizing the sub-passage 131, and under the action of the pressure, whether the sealing section 200 leaks or not is detected, so that the verification of the sealing performance of the sealing section 200 can be realized.
And S216, after the sealing performance of the sealing section 200 is confirmed to meet the requirement, reinstalling the second sealing element.
When the second tightness test of the sealing section 200 is completed and the sealing performance of the sealing section 200 is confirmed to meet the requirements, the second sealing element at the backpressure joint 160 can be reinstalled, and the whole system returns to a normal working state after the locking plates and the screws of the upstream and downstream nuts of the sealing section 200 are reinstalled.
To sum up, the core measurement system seal segment maintenance method of the embodiment of the application can independently relieve the pressure of the sub-passage 131 under the working condition that the system keeps under pressure so as to maintain the seal segment 200. The maintenance of the reactor core measuring system sealing section 200 is realized under the working condition of pressure, the withdrawal depth of the unit state during maintenance is reduced, the nuclear fuel is prevented from being removed again and the old finger sleeve 110 is prevented from being pulled out, the operation steps during maintenance are reduced, the construction period of defect treatment of the sealing section 200 is shortened, and the available power generation time of a nuclear power unit is prolonged. Meanwhile, the overhauling method avoids using a hard packing picking tool to take out the packing, and can effectively protect the sealing surface of the upstream sealing sleeve 220 and the surface of the thimble tube 110. Under the condition that a primary loop has pressure, the seal segment 200 is disassembled, checked and processed without complete pressure relief of the primary loop. Under the condition that a primary loop has pressure, the sealing performance of the sealing section 200 is verified in advance, and the situation that leakage is repeatedly processed after ascending is avoided.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A maintenance method for a reactor core measurement system seal section is characterized by comprising the following steps:
reducing the pressure in the main passage and partially drawing out the finger sleeve; the main passage is positioned between the finger sleeve and the guide tube sleeved outside the finger sleeve and is communicated with the reactor pressure vessel;
ice plugging the main passageway at a location between the reactor pressure vessel and the seal section to separate a sub-passageway in the main passageway on a side adjacent the seal section; the finger sleeve is arranged in a fuel assembly in the reactor pressure vessel in a penetrating way, and the sealing section is positioned at one end, deviating from the reactor pressure vessel, of the guide pipe;
releasing residual pressure within the sub-passage;
disassembling the seal section;
and taking out the first sealing element in the sealing section and carrying out maintenance.
2. The core measurement system seal segment servicing method of claim 1, wherein the step of ice plugging the primary passageway at a location between a reactor pressure vessel and a seal segment comprises:
performing ice blocking on the main passage at a position between a penetrating piece sleeved outside the guide pipe and the isolation valve; the penetration is located between the reactor pressure vessel and the seal section, and the isolation valve is located between the penetration and the seal section.
3. The core measurement system seal segment servicing method of claim 2, wherein the step of relieving residual pressure within the sub-passageway comprises:
removing a second seal on a back pressure fitting in communication with the sub-passage to relieve residual pressure within the sub-passage; the back pressure joint is located between the isolation valve and the sealing section.
4. The core measurement system seal segment servicing method of claim 3, wherein the step of disassembling the seal segment comprises:
cutting off the thrust section and the extension section connected with the finger sleeve, and removing the sleeve in the sealing section to enable the sub-passage to be communicated with the outside; one end of the thimble tube, which is far away from the reactor pressure vessel, penetrates through the sealing section and is connected with the thrust section and the extension section, and one end of the sleeve is sleeved on the end part of the guide tube.
5. The core measurement system seal segment servicing method of claim 4, wherein the step of removing and servicing a first seal in the seal segment comprises:
pressurizing the sub-passage from the back pressure joint to flush the first seal from the seal section.
6. The core measurement system seal segment servicing method of claim 5, wherein the step of pressurizing the sub-passageway by the back pressure joint comprises:
and connecting one end of a pressure pipeline with the back pressure joint, connecting the other end of the pressure pipeline with a pressure pump, and pressurizing the inside of the sub-passage through the pressure pump.
7. The core measurement system seal segment servicing method of claim 5, further comprising, after the step of removing and servicing the first seal in the seal segment, the steps of:
and reinstalling the first sealing element and the sleeve, and carrying out a first sealing test on the sealing section.
8. The core measurement system seal segment servicing method of claim 7, further comprising, after the steps of reinstalling the first seal and the sleeve, performing a first leak test on the seal segment, and passing the test, the steps of:
and reconnecting the thrust section and the extension section with the finger sleeve, removing ice blockage to reconnect the main passage, restoring the finger sleeve to the original position, then performing ice blockage again, and performing a second tightness test on the sealing section.
9. The core measurement system seal segment servicing method of claim 7 or 8, wherein the step of performing a leak test on the seal segment comprises:
and pressurizing the inside of the sub-passage at the back pressure joint, and checking whether leakage occurs at the sealing section.
10. The core measurement system seal segment servicing method of claim 8, wherein the step of performing the second leak testing and qualifying the seal segment further comprises the steps of:
reinstalling the second seal on the back pressure fitting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110888843.XA CN113782237B (en) | 2021-08-03 | 2021-08-03 | Maintenance method for seal section of reactor core measurement system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110888843.XA CN113782237B (en) | 2021-08-03 | 2021-08-03 | Maintenance method for seal section of reactor core measurement system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113782237A true CN113782237A (en) | 2021-12-10 |
| CN113782237B CN113782237B (en) | 2024-03-29 |
Family
ID=78836718
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110888843.XA Active CN113782237B (en) | 2021-08-03 | 2021-08-03 | Maintenance method for seal section of reactor core measurement system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113782237B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2736193A1 (en) * | 1995-06-30 | 1997-01-03 | Framatome Sa | Device for sealing an instrument channel in a PWR |
| EP0756129A2 (en) * | 1995-07-26 | 1997-01-29 | Canadian Fracmaster Ltd | Method and apparatus for forming solid phase plugs in pipelines |
| CN203480851U (en) * | 2013-10-18 | 2014-03-12 | 中广核核电运营有限公司 | Online sealing performance detection equipment of reactor core measuring system of pressurized water reactor nuclear power plant |
| CN103680644A (en) * | 2013-11-29 | 2014-03-26 | 北京广利核系统工程有限公司 | Sealing device connected with guide pipeline opening of pressure container |
| CN103915124A (en) * | 2013-10-18 | 2014-07-09 | 中广核核电运营有限公司 | Nuclear power station conventional island desalted water distribution system full-stop overhauling method |
| CN205104243U (en) * | 2015-11-10 | 2016-03-23 | 大亚湾核电运营管理有限责任公司 | Stifled isolation structure of online ice of nuclear power station pipeline |
| CN111667931A (en) * | 2020-05-08 | 2020-09-15 | 福建福清核电有限公司 | Reactor pressure vessel neutron flux measurement channel seal assembly and replacement method thereof |
| CN213225266U (en) * | 2020-08-10 | 2021-05-18 | 中广核核电运营有限公司 | A dactylotheca pipe cutting separator assembly for reactor core measurement system |
| CN213746167U (en) * | 2020-09-30 | 2021-07-20 | 中核核电运行管理有限公司 | Nuclear power chemical pipeline ice plug isolation testing device |
-
2021
- 2021-08-03 CN CN202110888843.XA patent/CN113782237B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2736193A1 (en) * | 1995-06-30 | 1997-01-03 | Framatome Sa | Device for sealing an instrument channel in a PWR |
| EP0756129A2 (en) * | 1995-07-26 | 1997-01-29 | Canadian Fracmaster Ltd | Method and apparatus for forming solid phase plugs in pipelines |
| CN203480851U (en) * | 2013-10-18 | 2014-03-12 | 中广核核电运营有限公司 | Online sealing performance detection equipment of reactor core measuring system of pressurized water reactor nuclear power plant |
| CN103915124A (en) * | 2013-10-18 | 2014-07-09 | 中广核核电运营有限公司 | Nuclear power station conventional island desalted water distribution system full-stop overhauling method |
| CN103680644A (en) * | 2013-11-29 | 2014-03-26 | 北京广利核系统工程有限公司 | Sealing device connected with guide pipeline opening of pressure container |
| CN205104243U (en) * | 2015-11-10 | 2016-03-23 | 大亚湾核电运营管理有限责任公司 | Stifled isolation structure of online ice of nuclear power station pipeline |
| CN111667931A (en) * | 2020-05-08 | 2020-09-15 | 福建福清核电有限公司 | Reactor pressure vessel neutron flux measurement channel seal assembly and replacement method thereof |
| CN213225266U (en) * | 2020-08-10 | 2021-05-18 | 中广核核电运营有限公司 | A dactylotheca pipe cutting separator assembly for reactor core measurement system |
| CN213746167U (en) * | 2020-09-30 | 2021-07-20 | 中核核电运行管理有限公司 | Nuclear power chemical pipeline ice plug isolation testing device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113782237B (en) | 2024-03-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100909443B1 (en) | Test apparatus and method for safety valve | |
| KR101040809B1 (en) | Sealing Test Device for Motor Actuation Parallel Gate Valve on Reactor Coolant System | |
| KR20070036094A (en) | Safety valve test bench | |
| CN107179169B (en) | A kind of nuclear power station check valve action test set and test method | |
| KR100963047B1 (en) | Sealing test device for swing check valve on reactor coolant pressure boundary | |
| CN113782237A (en) | Maintenance method for reactor core measurement system sealing section | |
| KR100540308B1 (en) | Apparatus for a test of leakage of presser safety valve and pressure setting up | |
| KR101221631B1 (en) | Apparatus of performance testing console for the Pilot Operated Check Valve | |
| CN203480851U (en) | Online sealing performance detection equipment of reactor core measuring system of pressurized water reactor nuclear power plant | |
| CN106644289B (en) | Temporary device for in-service inspection hydrostatic test of nuclear power station and application method of temporary device | |
| CN206179528U (en) | Water gate pressure holding device during whole pressing experiment of containment | |
| KR101997405B1 (en) | Apparatus and method for preventing sealing damage of check valve on Reactor Coolant Pressure Hot Leg | |
| JP6348855B2 (en) | Emergency core cooling system for nuclear power plants | |
| CN215178413U (en) | Leakproofness verifying attachment of RIC dactylotheca pipe seal section | |
| CN108758331B (en) | Oil return overpressure detection and relief device of hydraulic piston type natural gas compressor unit | |
| CN209262265U (en) | For the pressure relief device on pressure gauge pipeline | |
| CN110207014B (en) | Protection system for preventing overpressure at inlet of condensate pump and operation method | |
| CN218480456U (en) | Nitrogen-charging pressure-reducing protection device for process gas compressor | |
| KR100916662B1 (en) | Test method of stability for natural gas facility | |
| CN106641359B (en) | Vacuum air inlet safety valve | |
| CN105890887B (en) | Harvard installation quality control method for steam turbine adjusting system of nuclear power station | |
| CN217059172U (en) | Experimental auxiliary device of containment penetration piece leakproofness | |
| CN211315249U (en) | Remedy device for leakage in ball valve of isostatic pressing machine and isostatic pressing machine system | |
| KR102076457B1 (en) | Device for testing motor pressurized leakage for central chiller compressor | |
| CN217878320U (en) | Online test device for pilot operated safety valve of nuclear power station |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |