In-service nuclear power station simulation reactor core device and method

Abstract

The invention specifically provides an in-service nuclear power station simulation reactor core device and method, the simulation device comprises a bottom plate and an assembly, the upper surface of the bottom plate is provided with a lower positioning pin used for positioning and installing the assembly; a guide hole is formed in the bottom of the assembly and can be matched with the lower positioning pin, and a positioning hole and a guide hole are formed in the top of the assembly and are matched with a positioning pin and a guide pin of a gripper of the loading and unloading machine respectively. The method comprises the following steps: step 1, testing accuracy; step 2, setting coordinate values; step 3, testing grabbing; step 4, measuring and calculating matching degree; under the water-free working condition of the reactor pool, the device is located in a low-collapse lower reactor internal storage rack area of the reactor pool, and on the premise that the radiation dose level is permitted, the purpose that personnel directly observe a loading and unloading machine positioning precision test can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of a simulation test of a loader and unloader for core positioning, and in particular to a device and method for simulating the core of a pressure vessel of an in-service nuclear power plant. Background Art

[0002] During a pressurized water reactor nuclear power plant overhaul, the loading and unloading machine required modification. After the modification, to verify the accuracy and reliability of the equipment's operation, the loading and unloading machine was operated to grasp and release nuclear fuel assemblies, and to conduct positioning accuracy tests within the reactor core. During the construction of the nuclear power plant units, equipment commissioning personnel were able to directly assess the operation of the loading and unloading machine at the core. However, after the reactor was operational, the radiation dose level no longer permitted personnel to enter, making it impossible for personnel to directly assess the accuracy and reliability of the equipment after the on-site modification.

[0003] For reactors currently in operation, the core assembly can only be simulated within the reactor pool of an active nuclear power plant due to equipment size limitations. Under these conditions, underwater video cameras can be used to conduct positioning accuracy tests of the modified loader and unloader operating dummy components within the reactor core. However, this method has limited observation angles, making it difficult to effectively measure test data and subject to test errors. Furthermore, if the loader and unloader fails a test, the unit must be decommissioned and drained before adjustments can be made, impacting the unit's overhaul window. Summary of the Invention

[0004] The purpose of the present invention is to provide a device and method for simulating the core of an in-service nuclear power plant, which can solve the problems of easy deviation in the observation process and complex operation of the existing core device in actual application.

[0005] The technical solution of the invention is as follows: A device and method for simulating the core of an in-service nuclear power plant, the simulated core device comprising: a base plate and an assembly, the upper surface of the base plate being provided with a lower positioning pin for positioning and installing the assembly; a guide hole being provided at the bottom of the assembly, which can be matched with the lower positioning pin, and a positioning hole and a guide hole being provided at the top of the assembly, which are respectively matched with the positioning pin and guide pin of the loader and unloader gripper.

[0006] Furthermore, the bottom plate is designed in a "cross-shaped" shape, and its surface is provided with penetrating weight-reducing holes for reducing the overall weight of the device; and reinforcing ribs are welded on its bottom for strengthening the strength of the device.

[0007] Furthermore, the position arrangement of the lower locating pin on the simulated core device is consistent with the nuclear reactor core design, meeting the positioning accuracy test requirements of the loader and unloader; and the top of the lower locating pin has a certain taper to ensure the guiding and protective effect when the component enters the simulated core device.

[0008] Furthermore, a foot cup is installed at the lower part of the base plate, and the horizontality and elevation of the device can be adjusted by telescoping.

[0009] Furthermore, positioning bolts are installed on the sides of the base plate for direction identification.

[0010] Furthermore, the device is made entirely of stainless steel, which is not easily corroded and can be used in humid and harsh environments.

[0011] A method for simulating a core of an in-service nuclear power plant comprises the following steps:

[0012] The first step is the accuracy test: operate the loader and unloader trolley to the determined coordinates, lower the main lifting mechanism, and confirm the alignment of the gripper and the component;

[0013] The second step is to set the coordinate values: set the coordinate values of the loading and unloading machine program to be consistent with the coordinate values of the simulated core device;

[0014] The third step is the gripping test: operate the loader to grab and release the component to confirm the engagement and disengagement of the gripper with the component;

[0015] The fourth step is to measure the matching degree: operate the loader to grab the component, lift it to the upper load limit, run the loader to the specified coordinate position, lower the main lifting mechanism, and confirm the alignment and position of the component with the positioning pins under the simulated core device;

[0016] The fifth step is the manual offset method test: operate the loader and unloader grabbing assembly to perform a manual offset method test to confirm that the test indicators meet the requirements.

[0017] Compared with the existing technology, the advantages of the present invention are:

[0018] 1. The simulated core device can be placed in the lower reactor internal component storage rack area of the reactor pool when the reactor pool is dry. Under the premise of reaching the radiation dose level, personnel can directly observe the positioning accuracy test of the loading and unloading machine.

[0019] 2. The structural design of the positioning bolts and foot cups makes the device directional and benchmark, and can also adjust the level and elevation of the device, thereby improving the practicality of the device.

[0020] 3. The positioning holes and guide holes of the components are designed to meet the gripping function of the loading and unloading machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A top view of a simulated core device of an in-service nuclear power plant provided by the present invention;

[0022] Figure 2This is a front view of a simulated core device of an in-service nuclear power plant provided by the present invention;

[0023] Figure 3 A schematic diagram of the top structure of the assembly provided by the present invention;

[0024] Figure 4 A schematic diagram of the bottom structure of the assembly provided by the present invention;

[0025] Figure 5 This is a schematic structural diagram of a simulated core device for an in-service nuclear power plant provided by the present invention;

[0026] Figure 6 This is a top view of a simulated core device of an in-service nuclear power plant provided by the present invention after moving components;

[0027] In the figure: 1. Positioning bolt; 2. Lower positioning pin; 3. Base plate; 4. Reinforcement rib; 5. Foot cup; 6. Assembly. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] like Figures 1-6 As shown, a simulated core device for an in-service nuclear power plant comprises a base plate 3 and an assembly 6. The base plate 3 has a "cross-shaped" design and is provided with weight-reducing holes extending through its surface to reduce the overall weight of the device. A reinforcing rib 4 is welded to its bottom to strengthen the device. A lower locating pin 2 is mounted on its upper surface for positioning and mounting the assembly 6. The position of the lower locating pin 2 on the simulated core device is consistent with the design of the nuclear reactor core, meeting the positioning accuracy test requirements of the loading and unloading machine. The top of the lower locating pin 2 has a certain taper to ensure that the assembly 6 provides guidance and protection when entering the simulated core device. A foot cup 5 is mounted on the lower portion of the base plate 3, which can adjust the level and elevation of the device by telescoping. A positioning bolt 1 is mounted on the side of the base plate 3 for direction identification. A guide hole is provided at the bottom of the assembly 6 to mate with the lower locating pin 2. A positioning hole and a guide hole are provided at the top of the assembly 6 to mate with the positioning pin and guide pin of the loading and unloading machine gripper, respectively. Furthermore, the simulated core device is made entirely of stainless steel, which is corrosion-resistant and suitable for use in humid and harsh environments.

[0030] A method for simulating a core of an in-service nuclear power plant, the method comprising the following steps:

[0031] The first step is the accuracy test: After operating the loader and unloader trolley to the determined coordinates, lower the main lifting mechanism, control the gripper to approach the component, confirm the alignment accuracy of the gripper guide pins and locating pins with the component guide holes and locating holes, and make fine adjustments according to the position.

[0032] The second step is to set the coordinate values: after confirming that the first step is correct, set the coordinate values of the loading and unloading machine program to be consistent with the coordinate values of the simulated core device after it is in place.

[0033] The third step is the gripping test: operate the loader to grab and release the components to confirm that the engagement and release of the gripper and the components are normal.

[0034] The fourth step is to measure the matching degree: grab and lift the component to the upper load limit, run the loader to the next specified coordinate position, lower the main lifting mechanism, and confirm that the guide hole under the component and the positioning pin of the device are accurately aligned, indicating that the positioning accuracy test of the loader has passed.

[0035] The fifth step is the manual offset test: Place the component on the device and present Figure 6 Position situation. Operate the loading and unloading machine to grab the component and perform the manual offset method test. Confirm that there is no interference between the component and the adjacent components during the offset process. This indicates that the manual offset method test of the loading and unloading machine meets the requirements.

[0036] In the description of the present invention, it should be noted that the terms "left end", "right end", "above", "below", "outside", "inside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0037] Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0038] The above-described embodiment merely represents one embodiment of the present invention. While the description is relatively specific and detailed, it should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A device and method for simulating a core of an in-service nuclear power plant, characterized in that: The device comprises: a base plate (3) and a component (6); a lower positioning pin (2) is installed on the upper surface of the base plate (3) for positioning and installing the component (6); a guide hole is opened at the bottom of the component (6) and can be matched with the lower positioning pin (2); a positioning hole and a guide hole are opened at the top of the component (6) and are respectively matched with the positioning pin and the guide pin of the loader and unloader gripper.

2. The device and method for simulating a core of an in-service nuclear power plant according to claim 1, characterized in that: The bottom plate (3) is designed in a "cross-shaped" shape, and a through-hole for reducing weight is opened on its surface to reduce the overall weight of the device; A reinforcing rib (4) is welded on the bottom thereof to enhance the strength of the device.

3. The device and method for simulating a core of an in-service nuclear power plant according to claim 1, characterized in that: The position arrangement of the lower positioning pin (2) on the simulated core device is consistent with the design of the nuclear reactor core, meeting the positioning accuracy test requirements of the loader and unloader; and the top of the lower positioning pin (2) has a certain taper to ensure the guiding and protective function of the component when entering the simulated core device.

4. The device and method for simulating a core of an in-service nuclear power plant according to claim 1, characterized in that: A foot cup (5) is installed at the lower part of the base plate (3), and the horizontality and elevation of the device can be adjusted by telescoping.

5. The device and method for simulating a core of an in-service nuclear power plant according to claim 1, characterized in that: Positioning bolts (1) are installed on the sides of the base plate (3) for direction identification.

6. The device and method for simulating a core of an in-service nuclear power plant according to claim 1, characterized in that: The device is made entirely of stainless steel, is not prone to corrosion, and can be used in humid and harsh environments.

7. The device and method for simulating a core of an in-service nuclear power plant according to any one of claims 1 to 6, characterized in that: The following steps are involved: The first step is the accuracy test: operate the loading and unloading machine's trolley and carriage to the determined coordinates, lower the main lifting mechanism, and confirm the alignment of the gripper and the assembly (6); The second step is to set the coordinate values: set the coordinate values of the loading and unloading machine program to be consistent with the coordinate values of the simulated core device; The third step is the gripping test: operate the loader to grip and release the assembly (6) to confirm the engagement and disengagement of the gripper with the assembly (6); The fourth step is to measure the matching degree: operate the loading and unloading machine to grab the component (6), lift it to the upper limit of the load, run the loading and unloading machine to the specified coordinate position, lower the main lifting mechanism, and confirm the alignment and positioning of the component (6) and the lower positioning pin (2) of the simulated core device; The fifth step is a manual offset method test: operate the loader grab assembly (6) to perform a manual offset method test to confirm that the test indicators meet the requirements.

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