Spent fuel storage grillwork pitch measuring method

Abstract

The invention belongs to a measuring method, and particularly relates to a spent fuel storage grillwork pitch measuring method. The method comprises the following steps: mounting; performing measurement; and calculating. The method has the remarkable effects that (1) the pitch measurement of spent fuel storage grillwork of Zhangzhou units 1 and 2 (areas I and II), units 3 and 4 in Xiangjiang River and small reactor in Xiangjiang River is completed; and (2) the pitch measurement method is suitable for pitch measurement of two storage cells of the spent fuel grillwork in the I area, and is also suitable for pitch measurement of two storage cells of the grillwork in the II area. And (3) the measurement data are only on the storage cells with the measured pitch, the number of the measurement data is reduced to the greatest extent through the measurement means taking the measurement data as the reference, the accumulative error caused by multiple times of measurement is avoided, and the accumulative error of the pitch measurement of the two storage cells is minimized. And (4) the measurement method is convenient to operate, high in detection efficiency and high in detection value accuracy.

Description

Technical Field

[0001] The present invention belongs to the field of measurement methods, and particularly relates to a method for measuring the grid pitch of a spent fuel storage rack. Background Art

[0002] The spent fuel storage rack is a core device in the nuclear fuel cycle and is widely used in in-reactor storage, intermediate off-reactor storage, and reprocessing plant storage.

[0003] For a brand-new structure high-density spent fuel storage rack, in order to further improve the critical safety and mechanical indexes and increase the spent fuel loading density, it is required to measure the grid pitch dimensions between the storage compartments and their adjacent / non-adjacent storage compartments in the horizontal and vertical directions after the spent fuel storage rack is manufactured. The tolerance of the grid pitch positioning dimension between every two storage compartments in the spent fuel storage rack is ±1.5 mm, and the dimensional accuracy requirement is very high. Since the center of the storage compartment is a virtual center and it is impossible to directly measure and read the data, it is difficult to collect data and the measurement difficulty is extremely high.

[0004] In order to ensure that the grid pitch dimension tolerances of more than two storage compartments do not accumulate, avoid the drawbacks brought by the measurement method, affect the actual measured dimensions of the product, and further ensure the measurement accuracy of the grid pitch between adjacent / non-adjacent storage compartments, it is necessary to adopt a measurement method with high detection numerical accuracy to ensure the measurement requirements of the grid pitch of the storage compartment. Therefore, this measurement method is specifically invented. Summary of the Invention

[0005] Aiming at the defects of the prior art, the present invention provides a method for measuring the grid pitch of a spent fuel storage rack.

[0006] The present invention is implemented as follows: A method for measuring the grid pitch of a spent fuel storage rack, which includes the following steps

[0007] Step 1: Installation;

[0008] Step 2: Measurement;

[0009] Step 3: Calculation.

[0010] For a method for measuring the grid pitch of a spent fuel storage rack as described above, the step 1 includes the following content

[0011] Lift the spent fuel storage rack onto the detection platform.

[0012] For a method for measuring the grid pitch of a spent fuel storage rack as described above, the step 2 includes the following content

[0013] Measure respectively according to the situation of adjacent or non-adjacent storage compartments.

[0014] For a method for measuring the grid pitch of a spent fuel storage rack as described above, the step 2 includes the following content

[0015] Step 2.1: Measurement of adjacent storage compartments

[0016] Use an auxiliary straight ruler to lead out the measurement reference on the inner side of the storage compartment. After leading out, use a vernier caliper or a tape measure to measure the dimensions of L1 and L2;

[0017] Measurement method for the grid pitch between two adjacent storage compartments

[0018] - Dimension A is the inner cavity dimension of storage compartment A, and this dimension is not measured;

[0019] - Dimension B is the inner cavity dimension of storage compartment B, and this dimension is not measured;

[0020] - Dimension L1 is the dimension between the left side of the inner cavity of storage compartment A and the left side of the inner cavity of storage compartment B, and L1 needs to be measured;

[0021] - Dimension L2 is the dimension between the right side of the inner cavity of storage compartment A and the right side of the inner cavity of storage compartment B, and L2 needs to be measured;

[0022] - Dimension C is the dimension between the right side of the inner cavity of storage compartment A and the left side of the inner cavity of storage compartment B, and this dimension is not measured.

[0023] A method for measuring the grid pitch of a spent fuel storage rack as described above, wherein the second step includes the following content,

[0024] Step 2.2: Measurement of non - adjacent storage compartments

[0025] Lead out the measured dimension of the inner side reference of the storage compartment. After leading out, use a vernier caliper or a tape measure to measure the values of L1 and L2.

[0026] A method for measuring the grid pitch of a spent fuel storage rack as described above, wherein the third step includes the following content,

[0027] The calculation formula for the grid pitch dimension L between storage compartment A and storage compartment B is as follows:

[0028]

[0029] The remarkable effects of the present invention are: (1) According to this measurement method, the grid pitch dimensions of the storage compartments of the spent fuel racks in Units 1 and 2 (Zone I and Zone II) of Zhangzhou Nuclear Power Plant have been measured. The same measurement method is also used for the grid pitch measurement of the storage compartments of the spent fuel racks in Units 3 and 4 of Changjiang Nuclear Power Plant and the Changjiang small modular reactor.

[0030] (2) The grid pitch measurement method is applicable to the grid pitch measurement between two storage compartments of the spent fuel rack in Zone I, and is also applicable to the grid pitch measurement between two storage compartments of the rack in Zone II. According to the principle of this measurement method, this measurement method can be used for the grid pitch or spacing dimension measurement of parts of similar equipment.

[0031] (3) The measured data is only on the storage compartments of the measured pitch. Through the measurement means based on each other, the quantity of the measured data between the storage compartments is minimized to the greatest extent, avoiding the cumulative error of multiple measurements and minimizing the cumulative error of the pitch measurement of the two storage compartments.

[0032] (4) The measurement method is convenient to operate, has high detection efficiency and high accuracy of the detected values. Description of the Drawings

[0033] Figure 1 Schematic diagram of the pitch measurement of adjacent storage compartments;

[0034] Figure 2 Schematic diagram of the pitch measurement of non - adjacent storage compartments;

[0035] Figure 3 Process flow chart.

[0036] In the figure: 1. Storage compartment A; 2. Storage compartment B; 3. Water outlet plate; 4. Enclosure plate; 5. Auxiliary ruler. Detailed Implementation Manner

[0037] A method for measuring the pitch of a spent fuel storage rack includes the following steps

[0038] Step 1: Installation

[0039] Lift the spent fuel storage rack onto the detection platform.

[0040] Step 2: Measurement

[0041] Measure according to the situation of adjacent or non - adjacent storage compartments

[0042] Step 2.1: Measurement of adjacent storage compartments

[0043] Use an auxiliary straight ruler to lead out the measurement reference inside the storage compartment. After leading out, use a vernier caliper or a tape measure to measure the dimensions L1 and L2.

[0044] Method for measuring the pitch of two adjacent storage compartments,

[0045] —— Dimension A is the inner cavity dimension of storage compartment A, and this dimension is not measured;

[0046] —— Dimension B is the inner cavity dimension of storage compartment B, and this dimension is not measured;

[0047] —— Dimension L1 is the dimension between the left side of the inner cavity of storage compartment A and the left side of the inner cavity of storage compartment B, and L1 needs to be measured;

[0048] —— Dimension L2 is the dimension between the right side of the inner cavity of storage compartment A and the right side of the inner cavity of storage compartment B, and L2 needs to be measured;

[0049] —— Dimension C is the dimension between the right inner cavity of storage chamber A and the left inner cavity of storage chamber B, and this dimension is not measured;

[0050] Step 2.2: Measurement of non - adjacent storage chambers

[0051] Lead out the inner - side measurement reference of the storage chamber with an auxiliary ruler. After leading out, measure the values of L1 and L2 with a vernier caliper or a tape measure.

[0052] Step Three: Calculation

[0053] The calculation formula for the grid - pitch dimension L between storage chamber A and storage chamber B is as follows:

[0054]

Claims

1. A method for measuring the grid pitch of a spent fuel storage rack, characterized in that, Including the following steps Step 1: Installation; Step 2: Measurement; Step 3: Calculation.

2. The method for measuring the grid pitch of a spent fuel storage rack according to claim 1, characterized in that: The said Step 1 includes the following content, Lifting the spent fuel storage rack to the detection platform.

3. The method for measuring the grid pitch of a spent fuel storage rack according to claim 2, wherein: The said Step 2 includes the following content, Performing measurements separately according to the situations of adjacent or non - adjacent storage compartments.

4. The method for measuring the grid pitch of a spent fuel storage rack according to claim 3, wherein: The said Step 2 includes the following content, Step 2.1: Measurement of adjacent storage compartments Using an auxiliary straight ruler to lead out the inner - side measurement reference of the storage compartment, and after leading out, using a vernier caliper or a tape measure to measure the dimensions L1 and L2; Measurement method for the grid pitch between two adjacent storage compartments - Dimension A is the inner - cavity dimension of storage compartment A, and this dimension is not measured; - Dimension B is the inner - cavity dimension of storage compartment B, and this dimension is not measured; - Dimension L1 is the dimension between the left side of the inner cavity of storage compartment A and the left side of the inner cavity of storage compartment B, and L1 needs to be measured; - Dimension L2 is the dimension between the right side of the inner cavity of storage compartment A and the right side of the inner cavity of storage compartment B, and L2 needs to be measured; - Dimension C is the dimension between the right side of the inner cavity of storage compartment A and the left side of the inner cavity of storage compartment B, and this dimension is not measured.

5. The method for measuring the grid pitch of a spent fuel storage rack according to claim 3, characterized in that: The said Step 2 includes the following content, Step 2.2: Measurement of non - adjacent storage compartments Using an auxiliary ruler to lead out the inner - side measurement reference of the storage compartment, and after leading out, directly measuring the values of L1 and L2 with a vernier caliper or a tape measure.

6. A method for measuring the grid pitch of a spent fuel storage rack according to claim 4 or 5, characterized in that: The said Step 3 includes the following content, The calculation formula for the grid pitch dimension L between storage compartment A and storage compartment B is as follows:

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