JPH0577277B2 - - Google Patents

Description

[Detailed description of the invention] [Objective of the invention] (Industrial application field) The present invention measures the pulse count value from one neutron detector and the root mean square value (MSV) around the average value using the Campbell method. This invention relates to a wide-area neutron monitoring device (hereinafter referred to as a wide-range monitoring device) that monitors reactor neutron flux over a range of more than 10 orders of magnitude from the neutron source region to the intermediate region.

(Prior art) Conventionally, as one of the devices for monitoring the startup system reactor output used during startup operation of a nuclear reactor, 1
By measuring the pulse count value from the book neutron detector and the root mean square value around the average value using the Campbell method, we determined that
There are wide-range monitoring devices that monitor reactor neutron flux over an order of magnitude. Examples of this type of wide range monitor device include Japanese Patent Publication No. 18436/1984 (Random Pulse Monitoring Device), and several wide range monitor devices with different systems have been proposed. However, since this type of wide range monitor device is configured only with an analog signal processing circuit, adjustment is extremely complicated.

Therefore, recently, in order to automatically connect the pulse counting system and the Campbell system joint, etc., the pulse count value from the analogue signal processing circuit and the root mean square value from the Campbell measurement system have been A digital wide range monitor device has been proposed which converts the data into digital data and performs digital arithmetic processing on the digital data by a microprocessor.

(Problem to be solved by the invention) However, in each case, in the above-mentioned devices, in order to convert the minute current signal from the neutron detector into an optimal electric signal, special equipment is required at the site inside the reactor building. A system is adopted in which a stationary amplifier is installed and an electric signal containing a mixture of pulse signals and canvas signals is transmitted via a metal cable to the signal processing section of the monitoring unit installed in the central control center. For this reason, they are susceptible to plant noise, require special and expensive cables to be installed in conduit, or run common lines between neutron detectors or preamplifiers and central control center monitoring units. Even if special consideration was given to electrical continuity, etc., there was a problem in that the influence of plant noise could not be completely prevented. Furthermore, in order to process signals from a plurality of neutron detectors, it is necessary to install an independent preamplifier for each neutron detector and a plurality of cables for each channel.

Furthermore, with systems that install an analog preamplifier on-site, maintenance personnel must go to the site to input a calibration signal to the neutron detector input stage to confirm the integrity of the circuit loop. It was necessary to perform complex tasks such as disconnecting the neutron detector input cable, connecting a simulated signal source, and checking and calibrating the indicated values of the monitoring unit in the central control center. If the health of these circuit loops cannot be easily confirmed, the deterioration of the characteristics of the neutron detector may cause problems such as changing correction parameters during digital calculation processing, making it difficult to perform high-precision measurement and monitoring. I had a problem doing it.

In addition, the digital calculation type wide range monitor device that has been considered in the past requires the main part of its component circuit to be installed in the monitoring unit of the central control center, and due to circuit implementation constraints, only one channel can be detected. Since it is necessary to provide one monitoring unit to process the equipment signals, it has been difficult to consolidate and downsize the central control center equipment, and to centrally monitor multi-channel signals.

The purpose of the present invention is to reliably prevent the effects of plant noise without using special and expensive metal cables, and to easily check the health of circuit loops to perform high-precision measurement and monitoring. It is an object of the present invention to provide a digital wide range monitor device which can easily centralize and downsize central control center equipment and centrally monitor multi-channel signals.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides analog signal processing that converts each of the pulse signal and the canvas signal from the neutron detector into voltage signals and outputs the voltage signals. circuit, a pulse counter circuit that counts pulse signals from this analog signal processing circuit and outputs a pulse count value, and a root mean square value that calculates and outputs a root mean square value based on the canvas signal from the analog signal processing circuit. The health of the circuit system is checked for the circuit, the high-voltage power supply circuit for the detector that measures the DC current value from the neutron detector, converts it to a voltage signal and outputs it, and the input section of the analog signal processing circuit and the high-voltage power supply circuit for the detector. A calibration signal circuit that generates calibration signals for confirmation as necessary, and a first circuit that converts each analog output value from the pulse counter circuit, root mean square value circuit, and high-voltage power supply circuit for the detector into digital data and outputs it. A digital data processing circuit and each digital data from this digital data processing circuit is sampled sequentially at a fixed period, converted to optical data, and transmitted and outputted to the central control center via an optical transmission line in a self-propelled manner. An optical multiplexing processing unit comprising a multiplexing data processing section and a second digital data processing circuit that controls a calibration signal setting value in a calibration signal circuit using a digital data setting value from a monitoring unit described later. A storage unit that converts the optical data that is updated and transmitted in a self-propelled manner into electrical data and stores it again, digital data related to pulse count values stored in this storage unit, and digital data related to the root mean square value. A trip judgment is made by calculating the reactor output based on the data, and calculating the allowable increase in the reactor output from that point in time to a certain period of time based on the momentary output values of the reactor output. It is equipped with an arithmetic processing unit that performs the processing, and a setting data output circuit that converts the digital data setting value into optical data and transmits and outputs it to the optical multiplexing processing unit via the optical transmission line. It consists of a monitoring unit.

(Function) Therefore, in the digital wide range monitor device of the present invention, the pulse signal and the canvas signal from the neutron detector are converted into voltage signals by the analog signal processing circuit of the optical multiplexing processing unit, and then output. . Then, this pulse signal is counted by a pulse counter circuit to obtain a pulse count value, and the Campbell signal is calculated by a root mean square value circuit to obtain a root mean square value. Further, the DC current value from the neutron detector is measured by a high voltage power supply circuit for the detector and converted into a voltage signal. On the other hand, each analog output value from the pulse counter circuit, the root mean square value circuit, and the detector high voltage power supply circuit is converted into digital data by the first digital data processing circuit. Each digital data from the digital data processing circuit is sequentially sampled at a fixed period by the multiplexed data processing unit, converted to optical data, and transmitted in a self-propelled manner to the monitoring unit in the central control center via the optical transmission line. Output. On the other hand, optical data updated and transmitted in a self-propelled manner from the optical multiplexing processing unit is converted into electrical data and stored in the storage section of the monitoring unit. Then, the reactor power is calculated based on digital data related to the stored pulse count value and the root mean square value, and further based on the momentary output value of the obtained reactor power, Trip determination is performed by calculating the allowable increase in reactor power that is allowed after a certain period of time.

On the other hand, when checking the soundness of the circuit loop, the calibration signal circuit can be adjusted by transmitting the digital data setting value from the setting data output circuit to the second digital data processing circuit of the optical multiplexing processing unit. The signal setting values are controlled, and it becomes possible to generate and check the soundness of the circuit system by generating a calibration signal at the input section of the analog signal processing circuit and the high-voltage power supply circuit for the detector.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an example of the configuration of a digital wide range monitor device according to the present invention. Note that the figure shows a case where a three-channel neutron detector is provided. As shown in FIG. 1, the digital wide range monitor device of this embodiment has three
It receives output signals from the channel neutron detectors 1, 2, and 3, and is equipped with an optical multiplexing processing unit 4 installed at the site, a monitoring screen 5, and a monitoring unit 6 installed in the central control center. It consists of a pair of optical transmission lines 7 for transmitting and receiving optical data between the multiplexing processing unit 4 and the monitoring unit 6.

FIG. 2 is a block diagram showing an example of the internal configuration of the optical multiplexing processing unit 4 and the monitoring unit 6 in FIG. 1.

In FIG. 2, the optical multiplexing processing unit 4 is
An analog signal processing circuit 8 consisting of a preamplifier that converts the pulse signal and Campbell signal from the neutron detector 1 into voltage signals and outputs them, and counts the pulse signals from the analog signal processing circuit 8 to generate a pulse count value. a pulse counter circuit 9 that outputs a signal, a root mean square value circuit 10 that calculates a root mean square value based on the Campbell signal from the analog signal processing circuit 8 and outputs it, and measures a DC current value from the neutron detector 1 and calculates a voltage. At the input section of the high-voltage power supply circuit 11 for the detector, the analog signal processing circuit 8, and the high-voltage power supply circuit 11 for the detector, which are converted into signals and output,
Each analog output value from the calibration signal circuit 12, which generates a calibration signal as necessary to check the soundness of the circuit system, the pulse counter circuit 9, the root mean square value circuit 10, and the high-voltage power supply circuit for the detector 11, is digitalized. three first digital data processing circuits 13, 14 and 15 that convert into data and output;
Consisting of a timing circuit 16, a parallel/serial conversion circuit 17, and an electrical/optical signal conversion circuit 18, each digital data from each digital data processing circuit 13, 14, and 15 is sequentially sampled at the cycle specified by the timing circuit 16, and parallel/
A serial converter circuit 17 converts the parallel data into serial data, an electrical/optical signal converter circuit 18 converts the data into optical data, and the data is transmitted and output in a self-propelled manner to the monitoring unit 6 of the central control center via the optical transmission line 7. A multiplexed data processing section 19, an optical/electrical signal conversion circuit 20 that converts digital data setting values, which will be described later, transmitted as optical data from the monitoring unit 6 into electrical data, and a serial signal from the optical/electrical signal conversion circuit 20. A serial/parallel conversion circuit 21 that converts data into parallel data, and a serial/parallel conversion circuit 21 that converts data into parallel data.
A second digital data processing circuit 2 that controls the calibration signal setting value in the calibration signal circuit 12 based on the digital data setting value from the parallel conversion circuit 21
It consists of 2. Here, the first digital data processing circuit 15 also has a function of controlling the high voltage setting value in the detector high voltage power supply circuit 11 using the digital data setting value from the serial/parallel conversion circuit 21.

On the other hand, the monitoring unit 6 includes an optical/electrical conversion circuit 23 that converts the optical data updated and transmitted in a self-propelled manner from the optical multiplexing processing unit 4 into electrical data again, and from this optical/electrical conversion circuit 23. The reactor output is calculated based on a storage unit 24 consisting of a buffer memory that stores electrical data of 1 in a predetermined area, digital data related to pulse count values stored in this storage unit 24, and digital data related to the root mean square value. , and a calculation processing unit 25 that performs a trip determination by calculating the allowable increase value of the reactor power from that point in time until a certain period of time based on the momentary output values of the reactor power, and a high pressure set value. and a setting data output circuit 26 that outputs the calibration signal setting value as a digital data setting value.
and an electrical/optical conversion circuit 27 that converts the digital data setting value from the setting data output circuit 26 into optical data and transmits and outputs the data to the optical multiplexing processing unit 4 via the optical transmission line 7.

Next, the operation of the digital wide range monitor device configured as described above will be explained.

Pulse signal from neutron detector 1 (approximately 10 ^-1 cps
~10 ⁶ cps), and the fluctuation component (alternating current component in the hundreds of KHz band) generated by the superposition of these individual pulses, which is the subject of Campbell measurement, is sent to the analog signal processing circuit 8, and the The DC current signal as an average value is the high voltage power supply circuit 11 for the detector.
are input respectively. Analog signal processing circuit 8
In this case, the pulse signal and the Campbell signal are each converted into a voltage signal and output. Similarly, in the detector high voltage power supply circuit 11, a DC current signal is converted into a voltage signal and output. Further, the pulse counter circuit 9 counts pulse signals input one after another from the analog signal processing circuit 8 and outputs a pulse count value. The root mean square value circuit 10 calculates a root mean square value based on the Campbell signal from the analog signal processing circuit 8 and outputs it.

On the other hand, each analog output value from the pulse counter circuit 9, the root mean square value circuit 10, and the detector high voltage power supply circuit 11 is inputted to the first digital data processing circuits 13, 14, and 15, and is converted from analog to digital. Each is output as digital data. These digital data processing circuits 13, 14 and 1 including other channels
Each digital data from 5 is sequentially sampled in the multiplexed data processing unit 19 according to the instruction cycle of the timing circuit 16, and the parallel data is converted into serial data in the parallel/serial conversion circuit 17, and further subjected to electrical/optical signal conversion. The circuit 18 converts the data into optical data, and the data is transmitted to the monitoring unit 6 of the central control center via the optical transmission line 7 in a self-propelled manner.

On the other hand, the monitoring unit 6 installed in the central control center
In the optical/electrical conversion circuit 23, the optical serial data that is updated in a self-propelled manner and transmitted at regular intervals from the optical multiplexing processing unit 4 is converted into electrical parallel data and stored in a predetermined area of the storage section 24. Ru. Then, in the arithmetic processing unit 25, digital data related to the pulse count value stored in the storage unit 24,
The reactor output is calculated by combining the digital data related to the root mean square value and the reactor output, and based on the momentary output value of this reactor output, the allowable increase in the reactor output is allowed from that point until a certain period of time later. A trip determination is made by calculating the value. The results of this arithmetic processing are output and displayed on the monitoring screen 5 of the monitoring unit 6.

On the other hand, when checking the deterioration of the neutron detector characteristics and the health of the circuit loop, the high voltage setting value and the calibration signal setting value are output from the setting data output circuit 26 of the monitoring unit 6 as digital data setting values. The optical data is converted into optical data by the optical conversion circuit 27 and sent to the optical multiplexing processing unit 4 via the optical transmission line 7.
It is transmitted and output to. Then, in the optical/electrical signal conversion circuit 20 of the optical multiplexing processing unit 4, the digital data setting value transmitted as optical serial data from the monitoring unit 6 is converted into electrical data, and this serial data is sent to the serial/parallel conversion circuit. 21, it is converted into parallel data and output. Furthermore, a second digital data processing circuit 2
2, the high voltage power supply circuit for the detector is controlled by controlling the high voltage setting value in the high voltage power supply circuit 11 for the detector and the calibration signal setting value in the calibration signal circuit 12 using the digital data setting value from the serial/parallel conversion circuit 21. At the same time, a high voltage setting value is set in 11, and a calibration signal is generated at the input of the analog signal processing circuit 8 and the detector high voltage power supply circuit 11 to check for deterioration of the neutron detector characteristics and the soundness of the circuit system. can do.

As described above, in the digital wide range monitor device of this embodiment, the optical multiplexing processing unit 4 is provided at the site where the analog signal processing circuit 8 consisting of a preamplifier is installed, and subsequent data transmission is performed as optical digital data. Since we are trying to handle
Data processing can be performed without being affected by electrical noise caused by plant conditions between the field and the central control center. That is, it is possible to reliably prevent the effects of plant noise without using special and expensive metal cables as in the past. In addition, since the high voltage setting value and calibration signal setting value in the detector high voltage power supply circuit 11 and calibration signal circuit 12 provided inside the optical multiplexing processing unit 4 at the site are set using digital data, neutron detection is possible. Confirming the deterioration of device characteristics and the health of circuit loops, that is, performing maintenance and inspections, can be easily done from the monitoring unit 6 in the central control center, making it possible to perform highly accurate measurements and monitoring. becomes. Furthermore, since the digital data is sequentially sampled and transmitted at a fixed period, even for multiple neutron detectors,
Data processing can be easily performed simply by increasing the number of multiplexed channels in accordance with the number of neutron detectors, which in turn facilitates the consolidation of central control center equipment.
It becomes possible to make it more compact and to easily perform centralized monitoring of multi-channel signals. Furthermore, since the pulse count values and root mean square values that are updated at regular intervals from the optical multiplexing processing unit 4 are all digital data, the only arithmetic processing in the monitoring unit 6 is data conversion, and the reactor output percentage, etc. can be processed at high speed.

It should be noted that the present invention is not limited to the above-described embodiments, but can be similarly implemented in the following manner.

(a) In the above embodiment, the case where all the analog signal processing sections and digital signal processing sections including the preamplifier are provided for a 3-channel neutron detector was described as an example, but only for a 1-channel neutron detector. Similar effects can be obtained even if the configuration is configured as follows.

(b) The analog signal processing section in the optical multiplexing processing unit 4 of the above embodiment other than the preamplifier section and the digital signal processing section are separate units,
By arranging this separately from the preamplifier section, only the preamplifier section can be installed on-site, making it easy to replace an existing plant. In this case as well, all data processing can be performed digitally, and advantages such as multi-channel centralized monitoring can be utilized.

(c) The configuration of the mean square value circuit 10 in the above embodiment uses the most common 12-bit ADC, which is necessary to process data with the same degree of precision as a conventional linear analog circuit. This is an example of the circuit configuration with the best cost performance as expected, and the root mean square value
It is possible to increase the resolution of the ADC, or conversely, increase the number of root mean square value circuits to reduce the resolution of the ADC.

[Effects of the Invention] As explained above, according to the present invention, the influence of plant noise can be reliably prevented without using special and expensive metal cables, and the soundness of the circuit loop can be easily confirmed. We provide highly reliable digital wide-range monitoring equipment that can perform high-precision measurement and monitoring as well as centralize and downsize central control center equipment and easily centrally monitor multi-channel signals. can.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a digital wide range monitor device according to the present invention, and FIG. 2 is a block diagram showing an example of the internal configuration of an optical multiplexing processing unit and a monitoring unit in the same embodiment. 1, 2, 3...neutron detector, 4...optical multiplexing processing unit, 5...monitoring screen, 6...monitoring unit, 7...optical transmission line, 8...analog signal processing circuit, 9... Pulse counter circuit, 10... Root mean square value circuit, 11... High voltage power supply circuit for detector, 1
2... Calibration signal circuit, 13, 14, 15... 1st
digital data processing circuit, 16... timing circuit, 17... parallel/serial conversion circuit, 1
8... Electrical/optical signal conversion circuit, 19... Multiplexed data processing section, 20... Optical/electrical signal conversion circuit, 2
DESCRIPTION OF SYMBOLS 1... Serial/parallel conversion circuit, 22... Second digital data processing circuit, 23... Optical/electrical conversion circuit, 24... Storage section, 25... Arithmetic processing section, 26... Setting data output circuit, 27...Electrical/optical conversion circuit.

Claims (1)

[Claims] 1. By measuring the root mean square value around the pulse count value from the neutron detector and the average value by the Campbell method, 10
A wide range monitor device that monitors reactor neutron flux over an order of magnitude or more includes an analog signal processing circuit that converts the pulse signal and the canvas signal from the neutron detector into voltage signals and outputs them, and a a pulse counter circuit that counts pulse signals and outputs a pulse count value; a root mean square value circuit that calculates and outputs a root mean square value based on the Campbell signal from the analog signal processing circuit;
Check the soundness of the circuit system at the detector high-voltage power supply circuit that measures the DC current value from the neutron detector, converts it to a voltage signal, and outputs it, and the analog signal processing circuit and the input section of the detector high-voltage power supply circuit. a calibration signal circuit that generates a calibration signal as necessary to perform the calibration; and a first circuit that converts each analog output value from the pulse counter circuit, the root mean square value circuit, and the high-voltage power supply circuit for the detector into digital data and outputs the digital data. A digital data processing circuit and each digital data from this digital data processing circuit is sampled sequentially at a fixed period, converted to optical data, and transmitted and outputted to the central control center via an optical transmission line in a self-propelled manner. an optical multiplexing processing unit comprising a multiplexed data processing section and a second digital data processing circuit that controls a calibration signal setting value in the calibration signal circuit based on a digital data setting value from a monitoring unit described later; A storage unit that converts the optical data that is updated and transmitted in a self-propelled manner from the processing unit back into electrical data and stores it, and the digital data related to the pulse count values stored in this storage unit and the root mean square value. The reactor output is calculated based on the relevant digital data, and based on the momentary output value of the reactor output, the allowable increase in the reactor output is calculated from that point in time until a certain period of time. The central control center includes an arithmetic processing unit that performs determination, and a setting data output circuit that converts digital data setting values into optical data and transmits and outputs the converted data to the optical multiplexing processing unit via the optical transmission line. A digital wide range monitor device comprising: a monitoring unit installed on the side; 2. A patent claim characterized in that an analog signal processing circuit and a first digital data processing circuit that process pulse signals and Campbell signals from a plurality of neutron detectors are provided independently for each neutron detector channel. The digital wide range monitor device according to item 1.