CN-119884533-B - Calculation method and calculation device for measuring control rod value by nuclear power plant rod dropping method

CN119884533BCN 119884533 BCN119884533 BCN 119884533BCN-119884533-B

Abstract

The invention relates to the technical field of nuclear power station safety test, in particular to a method and a device for calculating the value of a control rod measured by a rod falling method of a nuclear power plant, wherein the method comprises the following steps of obtaining neutron flux density n 0 corresponding to initial time T 0 and initial time T 0 before rod falling of a control rod to be measured, neutron flux density n 1 corresponding to time T 1 and time T 1 when rod falling is finished, and neutron flux density n 2 corresponding to any time T 2 and any time T 2 after rod falling is finished; calculating a period T 1 of the moment after the rod falls, acquiring the average generation time lambda of prompt neutrons and the total effective share beta eff of the delayed neutrons in all fission neutrons, and calculating the value of the control rod to be detected. Compared with the traditional method, the method considers the influence of the prompt neutrons, does not need to manually judge the starting point of a progressive value, and introduces the influence factors of the prompt neutrons Then, without waiting for the neutron flux to approach the progressive value, a more comfortable data point selection range can be provided.

Inventors

CAI GUANGMING
ZUO LUO
PENG XIAOPING
ZHANG SHENGBIN
MENG FANFENG
HE ZISHUAI

Assignees

福建福清核电有限公司

Dates

Publication Date: 20260512
Application Date: 20231023

Claims (6)

1. A calculation method for measuring the value of a control rod by a rod dropping method of a nuclear power plant is characterized by comprising the following steps: Acquiring neutron flux density n 0 of a control rod to be detected at an initial time t 0 before rod falling starts and corresponding to the initial time t 0 , neutron flux density n 1 of a control rod to be detected at a rod falling end time t 1 and corresponding to a rod falling end time t 1 , and neutron flux density n 2 of any time t 2 after rod falling ends and corresponding to any time t 2 ; According to the neutron flux density n 1 corresponding to the moment T 1 when the rod falling ends, the moment T 1 when the rod falling ends, the neutron flux density n 2 corresponding to the arbitrary moment T 2 and the arbitrary moment T 2 , and the period T 1 of the moment after the rod falling is calculated by combining the formula (1), Acquiring the average generation time lambda of the prompt neutrons and the total effective share beta eff of the prompt neutrons in all fission neutrons; Calculating the value |rho 1 | of the control rod to be detected according to the neutron flux density n 0 corresponding to the initial time T 0 , the average generation time Λ of the prompt neutrons, the total effective share beta eff of the delayed neutrons in all fission neutrons and the period T 1 of the time after rod falling by combining a formula (2),
2. The method according to claim 1, wherein the obtaining the neutron flux density n 0 corresponding to the initial time t 0 and the initial time t 0 before the rod dropping starts, the neutron flux density n 1 corresponding to the time t 1 when the rod dropping ends and the time t 1 when the rod dropping ends, and the neutron flux density n 2 corresponding to the arbitrary time t 2 and the arbitrary time t 2 after the rod dropping ends, includes: Before the rod dropping test starts, confirming that the reactor core is in a critical state; Recording an initial time t 0 of a control rod to be detected before the start of rod falling and neutron flux density n 0 corresponding to the initial time t 0 measured by an off-stack nuclear instrument; when a rod falling test starts, the control rod to be tested is downwards inserted to the bottom of the pile; After the rod dropping test is finished, recording neutron flux density n 1 corresponding to the moment t 1 when the rod dropping of the control rod to be tested is finished and the moment t 1 when the rod dropping is finished, which is measured by the off-stack nuclear instrument, and neutron flux density n 2 corresponding to any moment t 2 after the rod dropping is finished and the any moment t 2 , which is measured by the off-stack nuclear instrument.
3. The calculation method according to claim 1, wherein a difference between a time t 1 at which the rod drop ends and an initial time t 0 is 1s or less.
4. A computing device for measuring the value of a control rod by a rod dropping method of a nuclear power plant, which is characterized by comprising the following components: The acquisition module is used for acquiring neutron flux density n 0 of the control rod to be detected, which corresponds to an initial time t 0 before rod falling starts and the initial time t 0 , neutron flux density n 1 of the control rod to be detected, which corresponds to a time t 1 of rod falling ends and the time t 1 of rod falling ends, neutron flux density n 2 of any time t 2 after rod falling ends and the neutron flux density n 2 of any time t 2 , average generation time Λ of prompt neutrons and total effective share beta eff of the prompt neutrons in all fission neutrons; A calculating module, configured to calculate a period T 1 of a post-rod drop time according to the time T 1 when the rod drop is ended, the neutron flux density n 1 corresponding to the time T 1 when the rod drop is ended, the neutron flux density n 2 corresponding to the arbitrary time T 2 and the arbitrary time T 2 , and the formula (1), And calculating the value |rho 1 | of the control rod to be detected according to the neutron flux density n 0 corresponding to the initial time T 0 , the average generation time Λ of the prompt neutrons, the total effective share beta eff of the delayed neutrons in all fission neutrons and the period T 1 of the time after rod falling by combining a formula (2),
5. A computer readable storage medium having stored thereon computer executable instructions, which when executed by a processor, implement a method of calculating a rod value for a nuclear power plant rod drop method according to any one of claims 1 to 3.
6. An electronic device, comprising: A processor for executing the method for calculating the value of the control rod measured by the rod dropping method of the nuclear power plant according to any one of claims 1 to 3, and a memory for storing executable instructions of the processor.

Description

Calculation method and calculation device for measuring control rod value by nuclear power plant rod dropping method Technical Field The invention relates to the technical field of safety test of nuclear power plants, in particular to a calculation method and a calculation device for measuring control rod value by a rod dropping method of a nuclear power plant. Background The total value of the reactor control rods is directly related to the shutdown margin of the reactor. The rod dropping method for measuring the control rod value is to obtain the rod dropping and shutdown actual measurement data through a real-time data acquisition system of a power station computer, and then calculate the rod dropping value through an offline digital reactivity meter program. The assumption of the traditional rod dropping method is that the density of the delayed neutron precursor core is basically unchanged in the extremely short time before and after rod dropping, and the power level is rapidly changed to the progressive value after rod dropping, namelyThe conventional bar dropping method has the advantage of simplicity, and is shown in the following formula (1). However, the second assumption does not take into account the effect of prompt neutrons, and requires a human judgment of the starting point of a progressive value, which introduces measurement errors. Disclosure of Invention The invention aims to provide a calculation method and a calculation device for measuring the value of a control rod by a rod falling method of a nuclear power plant, which are used for solving the technical problem that the influence of prompt neutrons is not considered in the assumption of the traditional method, and a starting point of a progressive value is required to be judged manually. The technical scheme of the invention is as follows: the invention provides a method for calculating the value of a control rod measured by a rod dropping method of a nuclear power plant, which comprises the following steps: And obtaining neutron flux density n 0 of the control rod to be detected, which corresponds to an initial time t 0 and an initial time t 0 before rod falling starts, neutron flux density n 1 which corresponds to a time t 1 when rod falling ends and a time t 1 when rod falling ends, and neutron flux density n 2 which corresponds to any time t 2 and any time t 2 after rod falling ends. According to the neutron flux density n 1 corresponding to the moment T 1 of the end of the rod falling, the moment T 1 of the end of the rod falling, the neutron flux density n 2 corresponding to any moment T 2 and any moment T 2, and the period T 1 of the moment after the rod falling is calculated by combining the formula (2), The average generation time lambda of the prompt neutrons and the total effective share beta eff of the delayed neutrons in all fission neutrons are obtained. Calculating the value |rho 1 | of the control rod to be detected according to the neutron flux density n 0 corresponding to the initial time T 0, the average generation time lambda of prompt neutrons, the total effective share beta eff of delayed neutrons in all fission neutrons and the period T 1 of the moment after rod falling by combining a formula (3), Obtaining neutron flux density n 0 corresponding to initial time t 0 and initial time t 0 before the beginning of rod dropping of a control rod to be detected, neutron flux density n 1 corresponding to time t 1 when rod dropping is finished and time t 1 when rod dropping is finished, The neutron flux density n 2 corresponding to any time t 2 and any time t 2 after the rod drop is finished comprises the steps of confirming that a reactor core is in a critical state before the rod drop test is started, recording the initial time t 0 of a control rod to be tested before the rod drop is started and the neutron flux density n 0 corresponding to the initial time t 0 measured by an off-stack nuclear instrument, inserting the control rod to be tested to the bottom of a reactor at the beginning of the rod drop test, recording the neutron flux density n 1 corresponding to the time t 1 when the rod drop is finished and the time t 1 when the rod drop is finished measured by the off-stack nuclear instrument after the rod drop test is finished, And neutron flux density n 2 corresponding to any time t 2 after rod drop is finished and any time t 2 measured by an off-stack nuclear instrument. The difference between the time t 1 when the falling rod ends and the initial time t 0 is less than or equal to 1s. The invention provides a computing device for measuring the value of a control rod by a rod falling method of a nuclear power plant, which comprises an acquisition module and a computing module. The acquisition module is used for acquiring neutron flux density n 0 of the control rod to be detected, which corresponds to an initial time t 0 and an initial time t 0 before rod falling starts, neutron flux density n 1 which correspon