阅读说明：本技术 一种反应堆停堆期间中子高通量报警系统及方法 (Neutron high-flux alarm system and method during reactor shutdown ) 是由 池毓凯 王岩 杨浩 许勇 季诚 吴海龙 王志强 李德银 林琰 钱双龙 于 2020-04-07 设计创作，主要内容包括：一种反应堆停堆期间中子高通量报警系统,包括探测器1,探测器1连接信号处理放大模块2,信号处理放大模块2连接计数器3,计数器3连接信号隔离分配模块4,隔离分配模块4分别连接计数率显示模块5、函数发生器6、阈值比较器7,函数发生器6连接拟更新的报警阈值显示模块8、信号选择器9、阈值比较器7,信号选择器9连接已生效的报警阈值显示模块10、阈值比较器7、确认修改报警阈值按钮11,阈值比较器7连接超阈值报警模块12。有效降低运行人员的监盘工作量,消除仪控维修人员修改报警阈值的维修工作量,有效提高工作效率,降低人因失误概率,达到降本增效的目的。(The utility model provides a neutron high flux alarm system during reactor shut-down, including detector 1, detector 1 connects signal processing and amplification module 2, signal processing and amplification module 2 connects counter 3, counter 3 connects signal isolation distribution module 4, isolation distribution module 4 connects count rate display module 5 respectively, function generator 6, threshold value comparator 7, function generator 6 connects the warning threshold value display module 8 of wanting to update, signal selector 9, threshold value comparator 7, signal selector 9 connects warning threshold value display module 10 that has taken effect, threshold value comparator 7, confirm to modify warning threshold value button 11, threshold value comparator 7 connects super threshold value alarm module 12. Effectively reduce operation personnel's supervision dish work load, eliminate the maintenance work load that instrument control maintenance personal revised the warning threshold value, effectively improve work efficiency, reduce the human error probability, reach the purpose of cost reduction increase.)

1. A neutron high flux alarm system during reactor shutdown is characterized in that: including detector (1), signal processing amplifier module (2) is connected in detector (1), counter (3) is connected in signal processing amplifier module (2), signal isolation distribution module (4) is connected in counter (3), count rate display module (5) are connected respectively in isolation distribution module (4), function generator (6), threshold value comparator (7), alarm threshold value display module (8) of plans the renewal are connected in function generator (6), signal selector (9), threshold value comparator (7), alarm threshold value display module (10) that has taken effect are connected in signal selector (9), threshold value comparator (7), confirm to modify alarm threshold value button (11), super threshold value alarm module (12) is connected in threshold value comparator (7).

2. A method of warning using the neutron high-flux warning system during a reactor trip of claim 1, wherein: the method comprises the following steps:

s1: the detector (1) outputs electric pulses under the action of detected neutrons;

s2: electric pulse signals output by the detector (1) are amplified, pulse shaped and amplitude discriminated by the signal processing and amplifying module (2), and frequency signals are output to the counter (3) for counting to obtain a counting rate n;

s3: the counting rate n signal is sent to the signal isolation and distribution module (4), and after the signal isolation and distribution module (4), the counting rate signal of (3) paths is output:

one path of counting rate signal is sent to a counting rate display module (5) for counting rate display;

one path of counting rate signal is sent to a threshold comparator (7) for threshold comparison;

one path of counting rate signal is sent to a function generator (6) for function calculation;

the function generator (6) receives two signals of a counting rate measured value n and a current alarm threshold value f (x0) of 3 phi, and judges the signals:

when in use

when in use

otherwise, the alarm threshold remains unchanged, i.e. f (x)₀)。

S4: clicking a confirmation and modification 3 phi alarm threshold button (11), and outputting a confirmation signal to a signal selector (9);

s5: after the signal selector (9) receives the confirmation signal, a new 3 phi alarm threshold value f (x) is selected and validated, and the automatic updating of the 3 phi alarm threshold value is completed;

s6: the signal selector (9) sends the effective alarm threshold value of 3 phi after confirmation to the effective alarm threshold value display module (10) and the threshold value comparator (7);

s7: the threshold comparator (7) receives the two signals of the alarm threshold of 3 phi and the counting rate and compares the two signals.

3. The method for neutron high-flux warning during reactor shutdown as claimed in claim 2, wherein in S1, the detector (1) is a boron-coated proportional counter.

4. The method for neutron high-flux alarm during reactor shutdown as claimed in claim 2, wherein in S1, an electric pulse with an amplitude of 100 μ V to 10mV is outputted.

5. The neutron high-flux alarm method during reactor shutdown as claimed in claim 2, wherein in S3, if the alarm threshold value is to be updated by 3 Φ, a prompt that the alarm threshold value is to be updated is popped up on the alarm threshold value display module (8) to be updated.

6. The neutron high-flux warning method during the reactor shutdown period according to claim 2, wherein in the step S3, the following information is provided at the same time:

the current 3 phi alarm threshold;

the current measured value meets the entrance specific condition of alarm threshold modification;

the updated 3 alarm threshold is to be modified.

7. The neutron high-flux alarm method during reactor shutdown period according to claim 2, wherein in step S5, if the counting rate measurement trend is found to be unstable and there is an exponential change, the 3 + alarm threshold button (11) is not clicked and modified, and the signal selector (9) does not receive the confirmation signal, and then the original 3 + alarm threshold f (x) is maintained₀)。

8. A reactor trip period neutron high flux as claimed in claim 2The alarm method is characterized in that in S5, if irregular large-range jumping exists, the 3 phi alarm threshold value button (11) is not clicked to confirm modification, and the signal selector (9) does not receive a confirmation signal, the original 3 phi alarm threshold value f (x) is kept₀)。

9. The method for neutron high-flux alarm during reactor shutdown according to claim 2, wherein in the step S7, when the count rate is greater than the alarm threshold value of 3 phi, the method outputs a high-flux alarm signal during reactor shutdown to the master control over-threshold alarm template (12).

Technical Field

The technology relates to the field of high neutron flux alarm threshold values of light water pressurized water reactor nuclear power units during shutdown, in particular to a high neutron flux alarm threshold value system and method during reactor shutdown.

Background

The nuclear power unit needs to continuously monitor the reactor core reactivity change under the condition of reactor shutdown, and immediately takes corrective measures (boronizing or inserting control rods and the like) to ensure the shutdown depth and prevent the reactor from being critical again when finding that the positive reactivity is introduced due to unexpected factors (such as mistaken dilution, mistaken lifting of the control rods and the like).

The PWR nuclear power unit monitors the reactor core reactivity change by monitoring the measurement count of the source range of the out-of-reactor nuclear measurement system in real time and setting an alarm threshold (generally called as a '3 phi alarm threshold') with high neutron flux during shutdown. During the shutdown and overhaul period of the unit, the source range measurement count is dynamically changed, and the set value of the alarm threshold value of 3 phi is irregularly modified correspondingly. At the initial stage of shutdown overhaul, the measurement number continuously decreases along with time and unloading progress, and the 3 phi alarm threshold value is set to be 2 times of the normal neutron flux level during the shutdown period; in the later period of overhaul, the measurement count is continuously improved along with the progress of charging, and the 3 phi alarm threshold value is set to be 3 times of the normal neutron flux level in the shutdown period.

At present, domestic power plants manually adjust the 3 phi alarm threshold value, a master control operator continuously supervises source range measurement counting, and when the source range measurement counting is smaller than 1/3 of the current 3 phi alarm threshold value or is larger than 2/3 of the current 3 phi alarm threshold value, an oncall instrument control maintenance worker modifies the 3 phi alarm threshold value.

Disclosure of Invention

The invention aims to: and automatic calculation and updating of the neutron flux high alarm threshold value during shutdown are realized, and the neutron flux high alarm threshold value takes effect after manual confirmation of a master control reactor operator. The method can effectively reduce the workload of monitoring the disk of the operator, eliminate the maintenance workload of instrument control maintenance personnel for modifying the alarm threshold, effectively improve the working efficiency, reduce the probability of human error and achieve the purposes of cost reduction and efficiency improvement.

The technical scheme of the invention is as follows: the utility model provides a neutron high flux alarm system during reactor shut-down, including the detector, the detector is connected signal processing and is enlargied the module, signal processing and enlargies the module and connect the counter, the counter is connected signal isolation distribution module, keep apart distribution module and connect count rate display module, function generator, threshold value comparator respectively, function generator connects the warning threshold value display module of wanting to update, signal selector, the threshold value comparator, signal selector connects warning threshold value display module, the threshold value comparator that has taken effect, confirm to modify warning threshold value button, the super threshold value alarm module of threshold value comparator connection.

A neutron high flux alarm method during a reactor shutdown period comprises the following steps:

s1: the detector outputs electric pulse under the action of the neutron to be detected;

s2: the electric pulse signal output by the detector is amplified, pulse shaped and amplitude discriminated by the signal processing and amplifying module, and a frequency signal is output to a counter for counting to obtain a counting rate n;

s3: the count rate n signal is sent to signal isolation distribution module, and after signal isolation distribution module, 3 count rate signals are exported:

one path of counting rate signal is sent to a counting rate display module for counting rate display;

one path of counting rate signal is sent to a threshold comparator for threshold comparison;

one path of counting rate signal is sent to a function generator for function calculation;

the function generator receives the count rate measurement n and the current 3 phi alarm threshold f (x)₀) These two signals, the signal judgment is made:

when in useUpdating the alarm threshold f (x) to 2 n;

when in use

When the alarm threshold f (x) is updated to be 2.8 n;

otherwise, the alarm threshold remains unchanged, i.e., f (x) f (x 0).

S4: clicking a 3 phi alarm threshold value button for confirming and modifying, and outputting a confirmation signal to a signal selector;

s5: after the signal selector receives the confirmation signal, the new 3 phi alarm threshold value f (x) is selected and validated, and the automatic updating of the 3 phi alarm threshold value is completed;

s6: the signal selector sends the effective alarm threshold value of 3 phi after confirmation to the effective alarm threshold value display module and the threshold value comparator;

s7: the threshold comparator receives two signals of the alarm threshold of 3 phi and the counting rate and compares the two signals.

In S1, the detector is a boron-coated proportional counter.

In S1, an electric pulse having an amplitude of 100 μ V to 10mV is output.

In the step S3, if the alarm threshold value of 3 phi needs to be updated, a reminder that the alarm threshold value needs to be updated is popped up on the alarm threshold value display module to be updated,

in S3, the following information is provided:

the current 3 phi alarm threshold;

the current measured value meets the entrance specific condition of alarm threshold modification;

the updated 3 alarm threshold is to be modified.

In S5, if the counting rate measurement trend is found to be unstable and the exponential change exists, the 3 phi alarm threshold value button is not clicked to confirm and modify, and the signal selector does not receive the confirmation signal, and the original 3 phi alarm threshold value f (x) is maintained₀)。

And in the S5, if irregular large-range jumping exists, the 3 phi alarm threshold value button is not clicked to confirm modification, and the signal selector does not receive the signalIf the signal is confirmed, the original 3 phi alarm threshold value f (x) is maintained₀)。

And in the step S7, when the counting rate is greater than the alarm threshold value of 3 phi, outputting a high-flux alarm signal in the shutdown period to the master control over-threshold alarm template.

The invention has the following remarkable effects: effectively reduce operation personnel's supervision dish work load, eliminate the maintenance work load that instrument control maintenance personal revised the warning threshold value, effectively improve work efficiency, reduce the human error probability, reach the purpose of cost reduction increase.

Drawings

FIG. 1 is a schematic diagram of a neutron high-flux alarm system during a reactor shutdown;

in the figure: the device comprises a detector 1, a signal processing and amplifying module 2, a counter 3, a signal isolation distribution module 4, a counting rate display module 5, a function generator 6, a threshold comparator 7, an alarm threshold display module 8 to be updated, a signal selector 9, an alarm threshold display module 10 which has come into effect, an alarm threshold button 11 for confirming modification 3 phi, and an alarm module 12 for exceeding the threshold

Detailed Description

A neutron high-flux alarm system during reactor shutdown comprises a detector 1, wherein the detector 1 is connected with a signal processing amplification module 2, the signal processing amplification module 2 is connected with a counter 3, the counter 3 is connected with a signal isolation distribution module 4, the isolation distribution module 4 is respectively connected with a counting rate display module 5, a function generator 6 and a threshold comparator 7, the function generator 6 is connected with an alarm threshold display module 8 to be updated, a signal selector 9 and a threshold comparator 7, the signal selector 9 is connected with an alarm threshold display module 10 which is effective, the threshold comparator 7 and an alarm threshold confirming and modifying button 11, and the threshold comparator 7 is connected with an over-threshold alarm module 12;

a neutron high flux alarm method during reactor shutdown comprises the following steps:

s1: the detector 1 (boron-coated proportional counter) outputs an electric pulse with the amplitude of 100 muV to 10mV under the action of a neutron to be detected;

s2: the electric pulse signal output by the detector 1 is amplified, pulse shaped and amplitude discriminated by the signal processing and amplifying module 2, and a frequency signal is output to the counter 3 for counting to obtain a counting rate n;

s3: the count rate n signal is sent to a DCS layer through a communication mode, and 3 paths of count rate signals are output after the signal isolation distribution module 4:

one path of counting rate signal is sent to a counting rate display module 5 for counting rate display;

one path of counting rate signal is sent to a threshold comparator 7 for threshold comparison;

one path of counting rate signal is sent to the function generator 6 for function calculation.

The function generator 6 receives the count rate measurement n and the current alarm threshold f (x) of 3 phi₀) These two signals, the signal judgment is made:

when in useUpdating the alarm threshold f (x) to 2 n;

when in use

When the alarm threshold f (x) is updated to be 2.8 n;

otherwise, the alarm threshold remains unchanged, i.e., f (x) f (x 0).

If the alarm threshold value of 3 phi needs to be updated, a prompt that the alarm threshold value needs to be updated pops up on the alarm threshold value display module 8 to be updated, and the following information is provided at the same time:

the current 3 phi alarm threshold;

the current measured value meets the entrance specific condition of alarm threshold modification;

the updated 3 alarm threshold is to be modified.

S4: clicking a confirmation modification 3 phi alarm threshold button 11, and outputting a confirmation signal to a signal selector 9;

s5: after the signal selector 9 receives the confirmation signal, a new 3 phi alarm threshold value f (x) is selected and validated, and the automatic updating of the 3 phi alarm threshold value is completed;

if the counting rate measurement trend is found to be unstable, the exponential change or irregular large-range jumping exists, the 3 phi alarm threshold value button 11 is not clicked to confirm and modify, the signal selector 9 does not receive the confirmation signal, and the original 3 phi alarm threshold value f (x) is kept₀)。

S6: the signal selector 9 sends the effective alarm threshold value of 3 phi after confirmation to the effective alarm threshold value display module 10 and the threshold value comparator 7;

s7: the threshold comparator 7 receives the two signals of the alarm threshold value of 3 phi and the counting rate, compares the two signals, and outputs a high-flux alarm signal during shutdown to the master control over-threshold alarm template 12 when the counting rate is greater than the alarm threshold value of 3 phi.