RU2785999C1 - Method for a comprehensive survey of the mine of an in-vessel nuclear reactor and a device for its implementation. - Google Patents

Abstract

FIELD: nuclear reactors.

SUBSTANCE: inventions group relates to a method and devices for monitoring the internals of a VVER-type reactor from the outside. The method consists in taking readings when the inner vessel shaft is removed from the reactor vessel and installed in the inner vessel shaft inspection shaft using a bar device made in the form of a rectangular frame with a semi-elliptical cutout on the narrow long side with at least two compartments with chamber modules in the form of metal boxes where the camera and illuminator are located. The bar is placed between the inspection shaft of the internal vessel shaft and the reactor vessel, and readings are taken from the lower surface of the internal shaft during the movement of the internal shaft from the reactor vessel to the inspection shaft and using a ring device made in the form of an annular frame.

EFFECT: reduction of terms and simplification of the process of control of the internal devices of the VVER type reactor from the outside.

3 cl, 5 dwg, 2 ex

Description

SUBSTANCE: group of inventions relates to measuring equipment in the field of nuclear energy, in particular to a method and devices for monitoring internal devices of a VVER type reactor from the outside. This group of inventions is intended for carrying out automated remote control of the base metal and welded joints of the reactor core shaft (SHVK) by the method of visual and measuring control using television means in the period preceding operation and during the period of scheduled preventive maintenance.

The objects of control of ShVK are:

landing and contact surfaces;

the surfaces of the segment plates at the points of contact between the shaft and the flow separator;

longitudinal welded joints of shell parts;

circular welded joints of the shells between themselves and the shell with the bottom;

surfaces of the keyways in contact with the keys of the reactor vessel;

elliptical surface of the bottom and welded joints of supports with the surface of the bottom.

The control of the base metal and welded joints of the ShVK must be carried out in order to obtain data on the state of the metal of the controlled sections during the commissioning of the reactor plant and during periodic monitoring during the operation of the NPP. ShVK ensures the design placement and orientation of the tails of fuel assemblies in the fixed cells of the bottom, the distribution of the coolant at the inlet to the core and at the outlet of the reactor.

The prior art is known Device for scanning the outer surface of the reactor vessel according to the patent CN108257693 (A). The device contains a fixed frame, a circular guide equipped with an electric motor, a linear guide fixed perpendicular to the circular guide, and sets of scanning elements installed along the linear guide. The way to scan the outer surface of the reactor vessel is that the linear guide moves along the circular guide along the surface of the reactor vessel. The linear guide is equipped with a rotary cylinder, which rotates it around its axis and thus allows you to select the required scanning elements. As a result, control the outer surface of the reactor vessel. The disadvantage of the device and method are the complexity of assembly and preparation for work, large size, the need to stop technological operations for the duration of the control, which makes this control inefficient in terms of time costs.

The closest to the claimed group of inventions in terms of the problem to be solved is the device for monitoring the internal devices of the reactor from the outside according to patent RU157811, containing a vertically oriented support frame and a trolley, as well as a pan-tilt television camera, characterized in that a rotary console is introduced, fixed in the upper part of the trolley, made with the possibility of movement along the vertical guides of the support frame, and the pan-tilt television camera is fixed at the end of the rotary console. The control method consists in installing a support frame with a winch over the reactor inspection shaft, moving a trolley with a tilt-and-turn television camera along the inspection shaft guides along a predetermined path, which ensures inspection of large-sized products, for example, an internal reactor shaft. The disadvantages of the device and method of control are the complexity of assembly and preparation for work, large size, the need to stop the main technological operations for the period of control, the need to use a polar crane for control, which makes this control inefficient in terms of time. Also, large time and labor costs are required for the dismantling and decontamination of equipment after the inspection.

The proposed group of inventions solves the technical problem of eliminating these shortcomings, namely, it carries out a comprehensive examination of the technical condition of the elements of the internal nuclear reactor shaft from the outside without stopping the main technological operations for the duration of the control, which simplifies and speeds up the control process.

The technical result of the group of inventions is to reduce the time of the control procedure by carrying it out simultaneously with the movement of the in-vessel shaft (SHVK) from the reactor vessel to the revision shaft, as well as to simplify the assembly, installation and dismantling of equipment for monitoring, the availability of all objects during decontamination, in the operational reliability of the equipment.

The technical result is realized due to the following methods and design features of the group of inventions.

A method for a comprehensive inspection of a mine of an in-vessel nuclear reactor, including:

- transfer of the transport ShVK device (UTSH) from the ShVK revision shaft to the reactor pressure vessel and fastening it to the ShVK;

- installation of an inspection ring on the top of the shaft to control the outer cylindrical surface of the ShVK;

- installation of a bar to control the bottom of the ShVK along the way of its movement into the revision shaft;

- extraction of UTSh coupled with ShVK from the reactor vessel;

- moving UTSh in coupling with ShVK to the revision shaft;

- taking readings from the lower surface of the ShVK using a bar while moving the ShVK from the reactor vessel to the inspection shaft;

- taking readings from the side surface of the ShVK using a ring during the installation of the ShVK into the revision shaft, while, after lowering the ShVK, the UTSh is installed on the ring.

The ring for checking the outer cylindrical surface of the ShVK contains:

- a metal frame in the form of a ring with at least two compartments, each compartment containing a camera module;

- at least two camera modules, while the module contains a metal box with one wall made of transparent protective glass, inside which a television camera and a lighting system are located, and on one of the walls of the box there is a sealed connector for connecting a cable through which the camera module is connected to the control equipment through the switch.

The bar for the bottom control of the ShVK contains:

- a metal frame in the form of a bar with a semi-ellipse cutout on the narrow long side, inside which there are at least two compartments, each compartment containing a camera module;

- at least two camera modules, while the module contains a metal box with one wall in the form of a transparent protective glass, inside which a television camera and a system of illuminators are located, and on one of the walls of the box there is a sealed connector for connecting a cable through which the camera module is connected to the equipment control via a switch.

The group of inventions is illustrated by drawings.

Figure 1 shows a schematic representation of a comprehensive survey of the inside-case mine (SHVK) from the outside, where:

1 - transport device ShVK (UTSH);

2 - revision shaft ShVK;

3 - control bar;

4 - control ring.

The arrow shows the direction of installation of the ring.

Figure 2 shows the lowering of the ShVK in the revision shaft through the ring. The arrows show the direction of movement of the SVK, where

5 - mine inside the hull (SHVK);

6 - side surface of the ShVK;

7 - the lower surface of the ShVK.

Figure 3 shows a view of the control ring, where:

8 - ring-shaped metal frame;

9 - compartment;

10 – chamber module;

11 - switch.

Figure 4 shows a view of the control bar, where:

12 - metal frame with a semi-ellipse cut;

13 - compartment;

10 – chamber module;

11 - switch.

Figure 5 is a view of the camera module with a camera and illuminators:

14 - metal box;

15 - transparent wall;

16 - sealed connector;

17 - TV camera;

18 - illuminator.

Figure 5 shows the front wall of the chamber module on the left, the chamber module in section and its rear wall on the right.

Preparation for the inspection of the ShVK (5) consists in installing a ring (4) in the form of an annular metal frame (8) with compartments (9) for chamber modules (10) on the upper edge of the revision shaft (2). The camera modules are sealed metal boxes (14), on one wall (15) of which there is a transparent protective glass, on the other - a sealed connector (16) for connecting the cable, and inside there is a camera (17) and illuminators (18) in the form of an LED ribbons. The frame (8) consists of segments and is quickly assembled manually by employees into a ring (4) on the upper edge of the inspection shaft (2), and chamber modules (10) are installed in compartments (13) by the same employees. In this case, the ring (4) is installed in such a way that the UTSh (1) is installed on it in the standard position. After installation, the ring (4) remains at the top of the SVK inspection shaft (2) for the entire life of the NPP. A bar (3) in the form of a metal frame (12) with a semi-ellipse cutout, inside which compartments (13) for chamber modules (10) are located, is manually assembled by employees from segments and installed up to the revision shaft of the ShVK (2), for example, on the canyon floor near the reactor vessel, so that the edges of the bar are directed to the walls of the canyon. In the compartments (13) of the frame (12), camera modules (10) are manually installed by employees. The camera modules installed in compartments (9) and (13) of the corresponding frames (8) and (12) are connected to the control equipment through switches (11), which serve to reduce the number of cables going to the control equipment. At least two camera modules (10) must be installed on each frame (8) and (12) in order to survey all surfaces of the ShVK (5). Accordingly, the number of compartments (9) and (13) for camera modules must be at least two. Thus, the process of assembling and preparing equipment for examination is simplified in comparison with analogues. The equipment itself in the form of a ring and a bar is reliable in use, since there are no moving elements in their design.

The method of comprehensive examination of the SVK (5) is carried out as follows. ShVK is removed from the reactor vessel using the transport ShVK device (UTSH) (1) and moves to the shVK revision shaft (2). During the movement of the ShVK (5) above the bar (3) with chamber modules (10), the bottom surface of the ShVK (7) is being filmed. When lowering the SVK (5) into the inspection shaft (2), it passes inside the ring (4) with chamber modules (10), and the side surface of the SVK (6) is filmed. Compartments (9) and (13) for camera modules (10), respectively, in the bar (3) and the ring (4) are located in such a way as to ensure the survey of all surfaces of the ShVK (5). In this case, the operations of moving the ShVK (5) from the reactor vessel to the revision shaft of the ShVK (2) are carried out in any case, regardless of the need to perform control. Thus, a comprehensive examination of the SVK does not take additional time and does not require the performance of separate operations specifically for control. The survey results are stored as digital images in the non-volatile memory of the control equipment. At the end of the shooting, the analysis of the obtained images is performed, and a conclusion is issued on the results of the control.

After the inspection, the equipment is dismantled and decontaminated. First, the chamber modules (10) are disconnected from the control equipment, then they are removed from the ring (4) and the bar (3), the bar (3) is removed from the canyon floor and disassembled manually. The ring (4) is located at the top of the revision shaft of the ShVK (2) for the entire period of operation of the power unit and does not need to be dismantled, decontaminated. Next, the chamber modules (10) and bar segments (3) are decontaminated. For decontamination, standard equipment of the central hall of the NPP is used - an ultrasonic bath. Chamber modules (10) and bar segments (3) are alternately placed in it for a certain time. The dismantling of the equipment is easy to perform, carried out manually by two or three employees, and does not require the use of a polar crane. Decontamination of equipment with access to all parts does not take much time.

As a result, the procedure for a comprehensive examination of the ShVK does not take additional time, and preparation for the examination procedure for the installation of equipment and upon completion of the examination during its dismantling takes much less time than in analogues. The equipment used for testing in the form of a ring and a bar is reliable in use, since there are no moving elements in their design, which increases their performance.

Thus, the technical result is achieved - reducing the time of the control procedure, simplifying the process of assembly, installation and dismantling of equipment, the availability of all equipment objects during decontamination, and the operational reliability of the equipment.

Example 1

The assembly and testing of the device for a comprehensive examination of the ShVK was carried out on a full-scale simulator of the canyon of a VVER type reactor. A mounted ring of six segments with compartments for camera modules was installed on the upper edge of the revision shaft of the ShVK. Two people installed 84 camera modules into the compartments for the camera modules of the ring, and connected them to the control equipment through switches. At that time, a plank in the form of a metal frame with a semi-ellipse cutout of three segments with compartments for chamber modules was installed on the floor of the canyon so that the edges of the plank were directed towards the walls of the canyon. The same two people installed 26 camera modules into the compartments for camera modules of the strip, and connected them to the control equipment through switches. The canyon simulator was filled with water. The ShVK simulator was removed from the reactor vessel simulator, carried over the bar with chamber modules and lowered through the ring with chamber modules into the ShVK revision shaft simulator, and after lowering, the UTSh stood on the ShVK control ring. During the movement of the SVK over the bar with chamber modules, the lower surface of the SVK was surveyed, and when the SVK was lowered into the revision shaft inside the ring with chamber modules, the side surfaces of the SVK were surveyed. The survey results were stored as digital images in the non-volatile memory of the control equipment. After the shooting was completed, the analysis of the obtained images was performed, and a conclusion was issued on the results of the control. Thus, a comprehensive survey of the ShVK was carried out simultaneously with its movement from the reactor vessel to the revision shaft without additional time spent on the survey, which reduced the control time, and hence the downtime of the power unit, by 16 hours.

After the survey, the canyon is drained and the procedure for dismantling and decontaminating the equipment begins. First, the chamber modules are disconnected from the control equipment, then they are removed from the ring and the bar, the bar is removed from the canyon floor and disassembled manually within 10 minutes. The ring is located at the top of the inspection shaft for the entire period of operation of the power unit and does not need to be dismantled and decontaminated. Next, the chamber modules and bar segments are decontaminated.

For decontamination, an ultrasonic bath was used - this is the standard equipment of the central halls of the nuclear power plant. Chamber modules and bar segments were alternately placed in it for 10 minutes each. At the same time, 20 chamber modules or one bar segment were in the ultrasonic bath. The control equipment was treated with alcohol for 20 minutes. The decontamination of all equipment was carried out by three people within 1 hour and 30 minutes.

Example 2

The assembly and testing of the device for a comprehensive examination of the ShVK was carried out on a full-scale simulator of the canyon of a VVER type reactor. A mounted ring of two segments with compartments for chamber modules was installed on the upper edge of the revision shaft of the ShVK. Two camera modules were installed into the compartments for the chamber modules of the ring by one person, and they were connected to the control equipment through switches. At that time, a plank in the form of a metal frame with a semi-ellipse cutout of three segments with compartments for chamber modules was installed on the floor of the canyon so that the edges of the plank were directed towards the walls of the canyon. The same person installed 2 camera modules into the compartments for camera modules of the strip by the same person, and connected them to the control equipment through switches. The canyon simulator was filled with water. The ShVK simulator was removed from the reactor vessel simulator, carried over the bar with chamber modules and lowered through the ring with chamber modules into the ShVK revision shaft simulator, and after lowering, the UTSh stood on the ShVK control ring. During the movement of the SVK over the bar with chamber modules, the lower surface of the SVK was surveyed, and when the SVK was lowered into the revision shaft inside the ring with chamber modules, the side surfaces of the SVK were surveyed. The survey results were stored as digital images in the non-volatile memory of the control equipment. After the shooting was completed, the analysis of the obtained images was performed, and a conclusion was issued on the results of the control. Thus, a comprehensive survey of the ShVK was carried out simultaneously with its movement from the reactor vessel to the revision shaft without additional time spent on the survey, which reduced the control time, and hence the downtime of the power unit, by 10 hours.

After the survey, the canyon is drained and the procedure for dismantling and decontaminating the equipment begins. First, the chamber modules are disconnected from the control equipment, then they are removed from the ring and the bar, the bar is removed from the canyon floor and disassembled manually within 10 minutes. The ring is located at the top of the inspection shaft for the entire period of operation of the power unit and does not need to be dismantled and decontaminated. Next, the chamber modules and bar segments are decontaminated.

For decontamination, an ultrasonic bath was used - this is the standard equipment of the central halls of the nuclear power plant. Chamber modules and bar segments were alternately placed in it for 10 minutes each. At the same time, there were 4 chamber modules or one bar segment in the ultrasonic bath. The control equipment was treated with alcohol for 20 minutes. Decontamination of all equipment was carried out by three people within 40 minutes.

Claims (10)

1. A method for a comprehensive examination of the shaft of an in-vessel nuclear reactor of the VVER type from the outside, which consists in extracting the inside-vessel shaft from the reactor vessel, installing it in the revision shaft of the inside-vessel shaft, taking readings using a television camera and an illuminator, characterized in that - the inner vessel shaft is removed from the reactor vessel using a transport device; - a ring with at least two compartments is installed on the top of the revision shaft, - a TV camera and an illuminator are placed in the compartment, - a bar with at least two compartments is installed between the inspection shaft of the inside-vessel shaft and the reactor pressure vessel, - a TV camera and an illuminator are placed in the compartment, - take readings from the lower surface of the inner vessel shaft with the help of a bar during the movement of the inner vessel shaft from the reactor vessel to the inspection shaft, - then readings are taken from the side surface of the internal shaft with the help of a ring during the installation of the internal shaft into the revision shaft. 2. A bar for implementing the method according to claim 1, including the placement of a television camera and an illuminator, characterized in that it is made in the form of a rectangular frame with a semi-ellipse cutout on the narrow long side, inside which at least two compartments are located, the compartment contains a camera module, which made in the form of a metal box with one wall of transparent protective glass, a sealed connector is placed on the other wall of the box, and a television camera and an illuminator are placed inside the box. 3. A ring for implementing the method according to claim 1, including the placement of a television camera and an illuminator, characterized in that it is made in the form of an annular frame with at least two compartments, a camera module is placed in the compartment, while the module contains a metal box with one wall of transparent protective glass, a sealed connector is placed on the other wall of the box, and a television camera and an illuminator are placed inside the box.

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