RU2739575C1 - Reactor body monitoring system - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: invention relates to measurement equipment in the field of nuclear power engineering, in particular to devices for monitoring inside WWER reactor housing. Control system of the reactor housing comprises a frame that can move along the perimeter of the upper flange of the reactor housing, diagnostic equipment, electric motors with encoders. Distinctive feature of control system is that it comprises metal road arranged on upper flange of reactor housing, at least one upper circular motion module arranged on a metal road and having an electric motor with an encoder. At that, on upper module of circular movement frame is fixed, made in form of truss, on which there are at least one lower module of circular movement and at least one universal carriage for installation of diagnostic equipment. Universal carriage is equipped with an electric motor with an encoder and is placed on the truss with possibility of movement along it in vertical direction. Protective guard for safety of personnel is fixed on the upper flange of the reactor housing.

EFFECT: technical result of the invention consists in reducing the time of the reactor body monitoring procedure from the inside, the measurements accuracy, simplification of processes of preparation of the system for operation and decontamination after control, improvement of fail-safety, measures for safety of work performed by service personnel.

3 cl, 2 dwg

Description

The invention relates to measuring equipment in the field of nuclear power, in particular to devices for monitoring inside a VVER-type reactor vessel. The reactor vessel is monitored by various methods depending on the purpose of the control. This invention is intended for a comprehensive inspection of the technical condition of the reactor vessel from the inside and includes tools for conducting television-visual inspection (TVC) of the vessel and surfacing of the cylindrical part of the vessel, ultrasonic testing (UST) of the vessel's welded joints and surfacing of welded joints, as well as tools for delivering tools to the place of control.

Known is a manipulating device for monitoring a VVER reactor vessel of a nuclear power plant according to patent HRP20180310. The device contains a three-legged support installed on the reactor vessel, a rotary table with a drive located in the central part of the support, a telescopic mast connected to the rotary table. The lower part of the telescopic mast is equipped with a transverse guide with at least one retractable trolley, where the measuring probes are fixed, for movement in the radial direction from the center of the support. The disadvantages of the manipulator are the complexity of assembly and preparation for work, large dimensions, and low fault tolerance. Low fault tolerance is due to the fact that the failure of any element of the device or the exhaustion of its resource leads to stopping the control and removing the device from the reactor vessel using a polar crane, which significantly increases the control time and requires crane time.

A device for transferring equipment for monitoring the inner surface of a nuclear reactor vessel is known according to US patent 2015332796. The device comprises a transverse beam fixed to the nuclear reactor vessel, a rod fixed to the beam and located in the longitudinal direction inside the housing, with a bracket for fixing the control equipment, a lever for displacement control equipment to the inner peripheral surface of the nuclear reactor vessel. The disadvantage of the device is the restrictions on the movement of equipment and, as a result, control measurements.

A device for monitoring a VVER reactor vessel of a nuclear power plant is known according to GB2533735. The device contains a mounting unit and platforms for moving diagnostic equipment for monitoring the reactor vessel of a nuclear power plant. Each platform for moving the diagnostic equipment can make an up and down lifting movement and a flat rotary movement around the mounting assembly. Several platforms equipped with different equipment can be simultaneously attached to the mounting unit, which allows simultaneous monitoring of different parts of the reactor vessel. The disadvantages of this device are the complexity of assembly and preparation for work, large dimensions, large time and labor costs for decontamination of the installation after the control.

The closest to the claimed device in technical essence is an installation for non-destructive testing of nuclear reactors according to patent RU 2040052. The installation contains a movable frame and a scanning device mounted on the frame with the possibility of vertical movement and equipped with measuring elements. The frame is made in the form of an L-shaped tubular spatial structure, and the scanning device is in the form of a shell with positive buoyancy, containing a vertical turret, a gear wheel with power cylinders with measuring elements attached to them, and a laser device oriented vertically upward. The movement mechanisms of the L-shaped tubular structure are equipped with electric motors with encoders. The disadvantages of the installation are the complexity of the assembly, the presence of a large number of mechanisms and sensors, which negatively affects the reliability, maintainability and fault tolerance, as well as the absence of a protective barrier on the flange of the reactor vessel, which ensures the safety of personnel when they are near the open reactor vessel.

The proposed invention solves the technical problem of eliminating these shortcomings, namely, it carries out a comprehensive examination of the technical condition of the reactor vessel from the inside, increases the efficiency of the control process by reducing the time of the control procedure, measuring accuracy, simplifying the processes of preparing the system for operation and deactivation after the control, increasing the fault tolerance, measures are provided for the safety of the work carried out by the service personnel.

The technical result of the invention is to reduce the time of the procedure for monitoring the reactor vessel from the inside by means of TVC (television-visual control) and ultrasonic testing (ultrasonic testing), the accuracy of measurements and the safety of their performance by personnel by simplifying the assembly, installation and dismantling, the possibility of simultaneous monitoring of the reactor vessel with different equipment , delivery of equipment to all measured surfaces, accessibility of all objects during decontamination, increase of fail-safety, placement of a protective fence on the flange of the reactor vessel.

The technical result is realized due to the following design features of the control system of the reactor vessel from the inside, containing a frame that can move along the perimeter of the upper flange of the reactor vessel, diagnostic equipment, electric motors with encoders. A distinctive feature of the control system is that it contains a metal road located on the upper flange of the reactor vessel, upper circular movement modules located on the metal road and having electric motors with an encoder, a frame made in the form of a truss and fixed on the upper circular movement module, independent control modules for various purposes as diagnostic equipment. The control module for ultrasonic testing is located on the farm in a universal carriage, the control module for TV-visual control is located on the same or another farm in another universal carriage. The system also contains the lower revolving modules located on the farm. On the upper flange of the reactor vessel there is a safety fence for personnel safety.

The inspection system of the reactor vessel from the inside includes two types of inspection, physically divided into television-visual inspection of the vessel and the surfacing of the cylindrical part of the vessel, and also for ultrasonic testing of the vessel welded joints and surfacing on the vessel welded joints.

So, the control system includes:

- one or more truss for placing diagnostic equipment in universal carriages for ultrasonic testing (UZK) and for television and visual inspection (TVC) of the reactor vessel from the inside, which, using an electric motor with an encoder, can move along the truss vertically during measurements, the truss has a straight contour ;

- metal railroad for moving a farm or trusses in a horizontal plane around the circumference of the rector body, located on the upper flange of the reactor;

- the upper modules of circular movement are placed on a metal road and fastened to the upper ends of the trusses; they have electric motors with an encoder for moving the trusses around the circumference of the rector's body;

- the lower modules of circular movement are located at the ends of the vertical parts of the trusses, support the trusses in a vertical position when they move around the circumference of the rector's body;

- control modules in the form of sensors designed for conducting TVC and ultrasonic testing of the reactor vessel from the inside;

- protective fence.

The invention is illustrated by drawings.

FIG. 1 shows a schematic representation of the reactor pressure vessel internal control system, where:

1 - reactor vessel;

2 - reactor branch pipe;

3 - flange of the reactor vessel;

4 - metal railroad;

5 - upper module of circular movement;

6 - lower module of circular movement;

7 - farm;

8 - universal carriage for placing control modules;

9 - TCE control module;

10 - ultrasonic inspection module;

11 - electric motor with encoder;

12 - protective fence.

FIG. 2 shows a top view in a variant when two trusses are used to control the hull.

The control system of the reactor vessel from the inside is assembled and operates as follows. A metal railroad (4) with a protective fence (12) is mounted on the flange (3) of the reactor vessel (1). The upper modules of circular movement (5) will be moved along the metal road using electric motors with an encoder (11) installed on them. In parallel, the trusses are being assembled (7). The trusses are made up of parts about 2 meters long and are assembled by hand. Each truss assembly kit contains a part with a lower rotary module (6). Each part of the truss is equipped with a quick connector for connecting to each other. Further, trusses (7) with circular movement modules (5) are installed on the assembled road. Universal carriages (8) are installed on each truss. Modules for monitoring TVK (9) or UZK (10) are installed on universal carriages. In the process of control, the horizontal movement of the control module is carried out using the upper circular movement module and, as a result, the truss. Vertical movement is carried out using a universal carriage equipped with an electric motor, which moves up and down the truss. Then control begins. In the process of monitoring, the failure of any element of the system or the exhaustion of its resource does not lead to a stop of monitoring, because the system element is easy to dismantle and replace manually without stopping the inspection process. Dismantling of the control system of the reactor vessel is carried out in the reverse order, namely: first, the ultrasonic inspection (9) and TVK (10) modules are removed, then universal carriages (8) are removed from the trusses (7), the trusses (7) with circular displacement modules (5 ), after which the metal railroad (4) is removed together with the protective fence (12). The trusses and the metal rail with safety fencing are dismantled by hand.

The design of the control system of the reactor vessel from the inside, which is easily assembled / disassembled and installed on the reactor vessel, and the equipment for carrying out various control is placed in universal carriages on separate trusses, while the trusses can move in the horizontal plane, and the carriages move vertically along the trusses, allows carry out two types of inspection, physically separated into television-visual inspection of the body and surfacing of the cylindrical part of the body, and ultrasonic testing of welded joints of the body and surfacing on welded joints of the body, which significantly reduces the time of the testing procedure and increases the measurement accuracy due to the proximity of equipment for control to the surface of the reactor vessel from the inside with free movement over the entire surface of the vessel. As a result, by the totality of essential features, the process of monitoring the reactor vessel from the inside is simplified, the accuracy of defect detection is improved, the detection rate is increased, the fault tolerance is increased due to the possibility of replacing modules without removing the trusses, and thus a technical result and significant economic effect are achieved. In addition, the safety of the personnel is provided due to the protective fence. The effectiveness of the control from the applied method increases by many indicators presented above.

An example of implementation of the invention.

The assembly and testing of the RPV control system from the inside was carried out on a full-scale test bench - a VVER reactor pressure vessel simulator. On the upper flange of the body, an assembled metal railroad consisting of nine segments with a safety fence was installed. With the help of two people, they assembled two trusses of six segments, each with upper and lower modules of circular movement. The assembled trusses were installed on the assembled road along the walls of the reactor vessel from the inside. A universal carriage was installed on the farm, in which a control module with equipment for ultrasonic inspection was placed. A universal carriage was installed on another farm, in which a control module with equipment for TVK was placed. After the installation of the trusses, the television-visual inspection of the hull and the surfacing of the cylindrical part of the hull, as well as ultrasonic testing of the welded joints of the hull and the surfacing on the welded joints of the hull, began simultaneously. Measurements on the trusses are made by the TVK and ultrasonic testing equipment, placed in universal carriages, which move along the trusses along the body vertically, and the trusses move horizontally. At the same time, the TVK and UZK equipment is located close to the body, which allows more accurate measurements. Thus, a high-precision inspection of the entire reactor vessel from the inside was carried out. At the same time, it was carried out simultaneously with different equipment with a small number of personnel, which significantly reduced the time in man-hours of control.

After all measurements have been made, the procedure for dismantling and decontaminating the equipment begins. First, the UZK and TVK modules are removed, then universal carriages are removed from the trusses, the trusses with circular movement modules are removed, after which the metal railroad is removed along with the protective fence. The trusses and the metal rail with safety fencing are dismantled by hand. Further, all equipment is decontaminated.

An ultrasonic bath was used for decontamination - this is the standard equipment of the central halls of the NPP. In it were placed alternately two-meter segments of trusses for about 10 minutes each segment, then railway segments also for 10 minutes each, then two universal carriages for 60 minutes each and control modules for 60 minutes each. The orbital modules were treated with alcohol for 30 minutes each. The safety cage was treated with alcohol for 60 minutes.

The assembly of the control system of the reactor pressure vessel from the inside and dismantling required the participation of 2 maintenance personnel; the decontamination of all equipment was performed by 2 people within 9 hours and 30 minutes.

Claims (4)

1. The control system of the reactor vessel, containing a frame that can move around the perimeter of the upper flange of the reactor vessel, diagnostic equipment, electric motors with encoders, characterized in that it contains a metal road located on the upper flange of the reactor vessel, at least one upper module of circular movement, placed on a metal road and having an electric motor with an encoder, at least one frame made in the form of a truss and fixed on the upper module of circular movement, at least one lower module of circular movement, located on the farm, at least one universal carriage for placing diagnostic equipment, equipped with an electric motor with an encoder and placed on the farm with the ability to move along it in the vertical direction. 2. The system according to claim 1, characterized in that it comprises a personnel safety guard located on the upper flange of the reactor vessel. 3. The system according to claim 1, characterized in that it contains diagnostic equipment in the form of at least one control module for ultrasonic testing. 4. The system according to claim 1, characterized in that it contains diagnostic equipment in the form of at least one control module for television-visual control.

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