Method for remotely modifying high neutron fluence rate alarm constant value during shutdown period of nuclear power plant

Abstract

The invention belongs to the technical field of pressurized water reactor nuclear power plant nuclear power measurement, and particularly relates to a method for remotely modifying a high neutron fluence rate alarm constant value during shutdown of a nuclear power plant. The DCS logic processing part obtains the neutron counting rate from the nuclear power measurement cabinet in real time; generating a high neutron counting rate alarm and activating a sound alarm through threshold comparison, and generating a pre-high / low neutron counting rate alarm through threshold comparison; after the neutron counting rate pre-alarm is triggered, a new recommended value of a neutron counting rate high alarm threshold value is automatically calculated, and after the recommended value is audited or modified by an operator, the recommended value can be remotely downloaded to a DCS logic processing cabinet through monitoring of the operator and a manual control terminal. The burden of continuously monitoring the source range counting rate by an operator is relieved, the consumption of human resources is reduced, and meanwhile, the possibility that other important work is restricted due to the fact that constant value modification is not timely is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power measurement in a pressurized water reactor nuclear power plant, and in particular relates to a method for remotely modifying a high neutron injection rate alarm setting value during a shutdown period of a nuclear power plant. Background Art

[0002] During the shutdown of a pressurized water reactor nuclear power plant unit, especially during loading and unloading, the high neutron injection rate alarm setting needs to be frequently modified. The technical operating specifications require that the current nuclear measurement system source range count rate be between 1 / 3 and 1 / 2 of the alarm setting. When modifying the alarm setting of the current nuclear power measurement system used in domestic nuclear power plants, a dedicated laptop computer for modifying the setting must be connected to the cabinet, and then the setting must be manually modified according to the current count rate.

[0003] This modification method has the following disadvantages: It increases the burden on the operator. Usually the alarm setting needs to be modified before the count rate leaves the required range, and the main control operator needs to constantly monitor the changes in the count rate; it increases the consumption of human resources and may cause the setting to be modified untimely. The number of setting modifications for a material replacement overhaul exceeds 20 times. In many cases, the need for setting modification occurs at night, and it takes a certain amount of time for maintenance personnel to go from the standby location to the work site and prepare for work, which may cause the setting to be modified untimely and thus restrict other overhaul work (such as loading and unloading). Summary of the invention

[0004] The purpose of the present invention is to provide a method for remotely modifying the high neutron injection rate alarm setting during the shutdown period of a nuclear power plant. Based on the existing DCS system hardware of the nuclear power plant, an appropriate control program is designed to transfer the high neutron injection rate alarm logic during the shutdown period of the nuclear measurement system and the alarm setting modification function to the power plant DCS system. The control logic includes functions for assisting operators in determining parameter modification target values ​​and pre-alarm functions. Operators can easily complete the modification of alarm settings through monitoring information and control components on the monitoring screen of the main control room. This improvement reduces the burden of operators continuously monitoring the source range count rate, reduces human resource consumption, and reduces the possibility that untimely setting modification will restrict other important work.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for remotely modifying the high neutron injection rate alarm setting value during the shutdown period of a nuclear power plant.

[0007] Step 1: The nuclear power measurement cabinet transmits the measured source range neutron count rate data to the DCS logic processing cabinet in real time;

[0008] Step 2: The DCS logic processing cabinet first transmits the neutron count rate in real time to the operator monitoring and manual control terminal for display, and then takes the average value n of the neutron count rate in the most recent period. The DCS logic processing cabinet also completes the following actions, including:

[0009] (1) receiving a neutron fluence rate high alarm threshold generation mode and parameters corresponding to each mode from an operator monitoring and manual control terminal, and receiving a neutron fluence rate pre-alarm threshold generation mode and parameters corresponding to each mode from an operator monitoring and manual control terminal;

[0010] (2) receiving a neutron fluence rate high alarm threshold from the operator monitoring and manual control terminal, and transmitting a new value to each of the neutron fluence rate pre-high / low alarm threshold setting input boxes on the operator monitoring and manual control terminal at the same time as receiving the threshold;

[0011] (3) receiving the neutron fluence rate pre-high alarm threshold and neutron fluence rate pre-low alarm threshold from the operator monitoring and manual control terminal;

[0012] (4) When the mean neutron count rate is higher than the neutron flux rate high alarm threshold during shutdown, a neutron flux rate high alarm is generated and the sound alarm device in the island is activated through the control cable;

[0013] (5) When the average neutron fluence rate is higher than the neutron fluence rate pre-alarm threshold value during shutdown, a neutron fluence rate high pre-alarm is generated, and a new value is transmitted to the neutron fluence rate high alarm threshold setting input box on the operator monitoring and manual control terminal;

[0014] (6) When the average neutron fluence rate is lower than the neutron fluence rate pre-low alarm threshold during shutdown, a neutron fluence rate low alarm is generated, and a new value is transmitted to the neutron fluence rate high alarm threshold setting input box on the operator monitoring and manual control terminal;

[0015] (7) Receive the alarm lock signal from the operator monitoring and manual control terminal. After receiving the signal, all the above alarms cannot be triggered.

[0016] Step 2: Take the average of the neutron count rate over the most recent period: take one number per second, take 10 numbers in total, and then take the average.

[0017] Step 2: (2) The calculation rule of the new value is related to the neutron fluence rate pre-high / low alarm threshold generation mode, and the specific generation rule is shown in Table 1;

[0018]

[0019] Step 2: (5) The calculation rule of the new value is related to the neutron fluence rate high alarm threshold generation mode, and the specific generation rule is shown in Table 2;

[0020]

[0021] Step 2: (6) The calculation rule of the new value is related to the neutron fluence rate high alarm threshold generation mode, and the specific generation rules are shown in Table 2;

[0022]

[0023]

[0024] Operator monitoring and manual control terminal: There is a neutron fluence rate high alarm threshold setting input box. The value in the input box can be generated by step 2, or can be manually entered or modified by the operator. The input box is used with a confirmation button. When the operator presses the confirmation button, the neutron fluence rate high alarm threshold in the input box is transmitted to the DCS logic processing cabinet.

[0025] Operator monitoring and manual control terminal: There are one input box for setting the neutron injection rate pre-high / low alarm threshold. The value in the input box can be generated by step 2, or can be manually entered or modified by the operator. The input box is used with a confirmation button. When the operator presses the confirmation button, the neutron injection rate pre-high / low alarm threshold in the input box is transmitted to the DCS logic processing cabinet.

[0026] Operator monitoring and manual control terminal: Receive and display the neutron injection rate high alarm, neutron injection rate pre-high alarm, and neutron injection rate pre-low alarm from the DCS logic processing cabinet.

[0027] Operator monitoring and manual control terminals, DCS logic processing cabinets, nuclear power measurement cabinets, and island sound alarm devices have been deployed after the normal construction and commissioning of nuclear power units.

[0028] The beneficial effects achieved by the present invention are:

[0029] With the help of auxiliary programs, operators can conveniently modify the alarm threshold and pre-alarm threshold directly in the main control room without going to the local cabinet to modify it, reducing the consumption of human resources during overhaul and the possibility of untimely modifications restricting other important work; the pre-alarm function reduces the burden of operators to constantly monitor the counting rate. DETAILED DESCRIPTION

[0030] The present invention is described in detail below with reference to specific embodiments.

[0031] The hardware part includes the operator monitoring and manual control terminal, DCS logic processing cabinet, nuclear power measurement cabinet, and island sound alarm device. The above hardware has been deployed after the normal construction and commissioning of the nuclear power unit, and no additional addition is required, but it is necessary to lay the control cable from the DCS logic processing part to the sound alarm device in order to issue an alarm. The nuclear measurement system cabinet sends the measured source range count rate signal to the DCS logic processing part. The operation technical specification requires that the current count rate is between 1 / 3 and 1 / 2 of the current alarm setting. Therefore, two pre-alarm values ​​can be set, one for pre-high alarm and one for pre-low alarm. When the neutron count rate changes and triggers the pre-high alarm, the operator can set a new larger alarm setting and a larger pre-high alarm setting through the operator monitoring and manual control terminal, or choose not to update the alarm setting according to the actual situation. If it is not updated and the count rate continues to rise and exceeds the alarm setting, the alarm is triggered and an audible alarm is issued. When the count rate gradually decreases and triggers the pre-low alarm, the operator can decide whether to update the alarm value through the display terminal according to the actual situation.

[0032] The DCS logic processing part obtains the neutron count rate from the nuclear power measurement cabinet in real time; generates a high neutron count rate alarm and activates the sound alarm through threshold comparison, and generates a neutron count rate pre-high / low alarm through threshold comparison; automatically calculates the recommended value of the new neutron count rate high alarm threshold after the neutron count rate pre-alarm is triggered, and can be remotely downloaded to the DCS logic processing cabinet through the operator monitoring and manual control terminal after the operator reviews or modifies it; automatically calculates the recommended value of the new neutron count rate pre-high / low alarm threshold when the new neutron count rate high alarm threshold is downloaded and takes effect, and can be remotely downloaded to the DCS logic processing cabinet through the operator monitoring and manual control terminal after the operator reviews or modifies it; the automatic generation method and parameters of the neutron count rate high alarm threshold and pre-alarm threshold can be remotely set through the operator monitoring and manual control terminal to correct the calculation formula of the recommended value of the new alarm threshold and pre-alarm threshold; the neutron count rate high alarm and pre-high / low alarm can be locked through the operator monitoring and manual control terminal.

[0033] The hardware includes: operator monitoring and manual control terminal, DCS logic processing cabinet, out-of-core measurement cabinet, alarm speaker and its auxiliary units. The DCS cabinet can control the action of the speaker through hardware line logic signals.

[0034] The steps for remotely modifying the high neutron injection rate alarm setting during a nuclear power plant shutdown are as follows:

[0035] Step 1: The nuclear power measurement cabinet transmits the measured source range neutron count rate data to the DCS logic processing cabinet in real time.

[0036] Step 2: The DCS logic processing cabinet first transmits the neutron count rate in real time to the operator monitoring and manual control terminal for display, and then takes the average of the neutron count rate in the recent period (for example, one number is taken per second, a total of 10 numbers are taken, and then the average is taken, represented by the letter n). The DCS logic processing cabinet also completes the following actions, including:

[0037] (1) Receive the neutron fluence rate high alarm threshold generation mode and the parameters corresponding to each mode from the operator monitoring and manual control terminal (the role of the mode and parameters is explained in step 3), and receive the neutron fluence rate pre-alarm threshold generation mode and the parameters corresponding to each mode from the operator monitoring and manual control terminal (the role of the mode and parameters is explained in step 3).

[0038] (2) Receive the neutron fluence rate high alarm threshold from the operator monitoring and manual control terminal, and at the same time as receiving the threshold, transmit a new value to the neutron fluence rate pre-high / low alarm threshold setting input box on the operator monitoring and manual control terminal. The calculation rule of this value is related to the neutron fluence rate pre-high / low alarm threshold generation mode. The specific generation rule is shown in Table 1.

[0039] (3) Receive the neutron flux rate high alarm threshold and neutron flux rate low alarm threshold from the operator monitoring and manual control terminal.

[0040] (4) When the average neutron count rate is higher than the neutron flux rate high alarm threshold during shutdown, a neutron flux rate high alarm is generated and the sound alarm device in the island is activated through the control cable.

[0041] (5) When the average neutron fluence rate is higher than the neutron fluence rate high alarm threshold during shutdown, a neutron fluence rate high alarm is generated, and a new value is transmitted to the neutron fluence rate high alarm threshold setting input box on the operator monitoring and manual control terminal. The calculation rule of this value is related to the neutron fluence rate high alarm threshold generation mode. The specific generation rule is shown in Table 2.

[0042] (6) When the average neutron fluence rate is lower than the neutron fluence rate pre-low alarm threshold during shutdown, a neutron fluence rate low alarm is generated, and a new value is transmitted to the neutron fluence rate high alarm threshold setting input box on the operator monitoring and manual control terminal. The calculation rule of this value is related to the neutron fluence rate high alarm threshold generation mode. The specific generation rules are shown in Table 2.

[0043] (7) Receive the alarm lock signal from the operator monitoring and manual control terminal. After receiving the signal, all the above alarms cannot be triggered.

[0044] Step 3: The operator monitoring and manual control terminal has the following functions:

[0045] (1) Real-time display of the source range neutron count rate transmitted from the DCS logic processing cabinet;

[0046] (2) A neutron fluence rate high alarm threshold generation mode selection button is provided, which provides two optional modes, namely, difference mode and percentage mode. Corresponding parameters need to be set in each mode. After setting, the alarm threshold generation formula transmitted from the DCS logic processing cabinet to the neutron fluence rate high alarm threshold setting input box on the operator monitoring and manual control terminal is shown in Table 1.

[0047]

[0048] (3) A neutron fluence rate pre-high / low alarm threshold generation mode selection button is provided, which provides two optional modes, namely, difference mode and percentage mode. Corresponding parameters need to be set in each mode. After setting, the alarm threshold generation formula transmitted from the DCS logic processing cabinet to the neutron fluence rate pre-high / low alarm threshold setting input box on the operator monitoring and manual control terminal is shown in Table 2.

[0049]

[0050] (4) An alarm lock button is provided. When the operator presses the button, the DCS logic processing cabinet receives the lock signal and prevents all alarms described in step 2 from being triggered.

[0051] (5) An input box for setting a high neutron fluence rate alarm threshold value is provided. The value in the input box can be generated by step 2 or can be manually input or modified by the operator. The input box is used in conjunction with a confirmation button. When the operator presses the confirmation button, the high neutron fluence rate alarm threshold value in the input box is transmitted to the DCS logic processing cabinet.

[0052] (6) An input box for setting the neutron fluence rate pre-high / low alarm threshold is provided. The value in the input box can be generated by step 2 or can be manually input or modified by the operator. The input box is used in conjunction with a confirmation button. When the operator presses the confirmation button, the neutron fluence rate pre-high / low alarm threshold in the input box is transmitted to the DCS logic processing cabinet.

[0053] (7) Receive and display the neutron injection rate high alarm, neutron injection rate pre-high alarm, and neutron injection rate pre-low alarm from the DCS logic processing cabinet.

[0054] Based on the existing DCS system hardware of the nuclear power plant, an appropriate control program is designed to transfer the high neutron injection rate alarm logic and alarm setting modification function of the nuclear measurement system during shutdown to the power plant DCS system. The control logic includes functions for assisting operators to determine the target value of parameter modification and pre-alarm functions. Operators can easily modify the alarm setting through the monitoring information and control components on the monitoring screen of the main control room. This improvement reduces the burden on operators, reduces human resource consumption, and reduces the possibility of untimely setting modification.

Claims

1. A method for remotely modifying a high neutron fluence rate alarm setting value during a nuclear power plant shutdown, characterized in that: Step 1: The nuclear power measurement cabinet transmits the measured source range neutron count rate data to the DCS logic processing cabinet in real time; Step 2: The DCS logic processing cabinet first transmits the neutron count rate in real time to the operator monitoring and manual control terminal for display, and then takes the average value n of the neutron count rate in the most recent period. The DCS logic processing cabinet also completes the following actions, including: (1) receiving a neutron fluence rate high alarm threshold generation mode and parameters corresponding to each mode from an operator monitoring and manual control terminal, and receiving a neutron fluence rate pre-alarm threshold generation mode and parameters corresponding to each mode from an operator monitoring and manual control terminal; (2) receiving a neutron fluence rate high alarm threshold from the operator monitoring and manual control terminal, and transmitting a new value to each of the neutron fluence rate pre-high / low alarm threshold setting input boxes on the operator monitoring and manual control terminal at the same time as receiving the threshold; (3) receiving the neutron fluence rate pre-high alarm threshold and neutron fluence rate pre-low alarm threshold from the operator monitoring and manual control terminal; (4) When the mean neutron count rate is higher than the neutron flux rate high alarm threshold during shutdown, a neutron flux rate high alarm is generated and the sound alarm device in the island is activated through the control cable; (5) When the average neutron fluence rate is higher than the neutron fluence rate pre-alarm threshold value during shutdown, a neutron fluence rate high pre-alarm is generated, and a new value is transmitted to the neutron fluence rate high alarm threshold setting input box on the operator monitoring and manual control terminal; (6) When the average neutron fluence rate is lower than the neutron fluence rate pre-low alarm threshold during shutdown, a neutron fluence rate low alarm is generated, and a new value is transmitted to the neutron fluence rate high alarm threshold setting input box on the operator monitoring and manual control terminal; (7) Receive the alarm lock signal from the operator monitoring and manual control terminal. After receiving the signal, all the above alarms cannot be triggered.

2. The method for remotely modifying the high neutron fluence rate alarm setting value during shutdown of a nuclear power plant according to claim 1, characterized in that: Step 2: Take the average of the neutron count rate over the most recent period: take one number per second, take 10 numbers in total, and then take the average.

3. The method for remotely modifying the high neutron fluence rate alarm setting value during shutdown of a nuclear power plant according to claim 1, characterized in that: Step 2: (2) The calculation rule of the new value is related to the neutron fluence rate pre-high / low alarm threshold generation mode, and the specific generation rule is shown in Table 1; 4. The method for remotely modifying the high neutron fluence rate alarm setting value during shutdown of a nuclear power plant according to claim 3, characterized in that: Step 2: (5) The calculation rule of the new value is related to the neutron fluence rate high alarm threshold generation mode, and the specific generation rule is shown in Table 2; 5. The method for remotely modifying the high neutron fluence rate alarm setting value during shutdown of a nuclear power plant according to claim 3, characterized in that: Step 2: (6) The calculation rule of the new value is related to the neutron fluence rate high alarm threshold generation mode, and the specific generation rules are shown in Table 2; 6. The method for remotely modifying the high neutron fluence rate alarm setting value during shutdown of a nuclear power plant according to claim 1, characterized in that: Operator monitoring and manual control terminal: There is a neutron fluence rate high alarm threshold setting input box. The value in the input box can be generated by step 2, or can be manually entered or modified by the operator. The input box is used with a confirmation button. When the operator presses the confirmation button, the neutron fluence rate high alarm threshold in the input box is transmitted to the DCS logic processing cabinet.

7. The method for remotely modifying the high neutron fluence rate alarm setting value during shutdown of a nuclear power plant according to claim 1, characterized in that: Operator monitoring and manual control terminal: There are one input box for setting the neutron injection rate pre-high / low alarm threshold. The value in the input box can be generated by step 2, or can be manually entered or modified by the operator. The input box is used with a confirmation button. When the operator presses the confirmation button, the neutron injection rate pre-high / low alarm threshold in the input box is transmitted to the DCS logic processing cabinet.

8. The method for remotely modifying the high neutron fluence rate alarm setting value during shutdown of a nuclear power plant according to claim 1, characterized in that: Operator monitoring and manual control terminal: Receive and display the neutron injection rate high alarm, neutron injection rate pre-high alarm, and neutron injection rate pre-low alarm from the DCS logic processing cabinet.

9. The method for remotely modifying the high neutron fluence rate alarm setting value during shutdown of a nuclear power plant according to claim 1, characterized in that: Operator monitoring and manual control terminals, DCS logic processing cabinets, nuclear power measurement cabinets, and island sound alarm devices have been deployed after the normal construction and commissioning of nuclear power units.

Images