JP2001083280A - Reactor in-core instrumentation signal processing device and in-core instrumentation system - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an in-furnace instrumentation signal processing device capable of performing delayed gamma correction included in an output signal of a gamma thermometer assembly to more accurately obtain a signal proportional to a local output. I do. A delayed gamma component included in a GT signal representing a local power distribution of a power region in a reactor detected by a GT sensor is represented by a time constant and a weight, and the delayed gamma component is represented by the time constant and the weight. An in-furnace instrumentation signal processor 1 comprising: a GT field panel 3 and a GT control panel 4 for removing a gamma component from a GT signal to obtain a gamma thermometer signal free from the effect of a delayed gamma component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an in-core instrumentation signal processing device and an in-core instrumentation system for a nuclear reactor.

[0002]

2. Description of the Related Art For example, in a boiling water reactor (hereinafter, referred to as BWR) among reactors, as shown generally in FIGS. In the specification, a power distribution monitoring system for monitoring the power distribution of the nuclear reactor is described as “reactor power distribution”, “core power distribution”, etc.).

In a BWR, as shown in FIG.
A reactor pressure vessel 102 is stored in a reactor containment vessel 101, and a core 103 is placed in the reactor pressure vessel 102.
Is housed. As shown in FIG. 13, the reactor core 103 is configured by loading a large number of fuel assemblies 104, control rods 105, and the like. An in-furnace instrumentation assembly 106 is provided at a position surrounded by the fuel assembly 104 in the reactor core 103.

As shown in FIG. 13, four fuel assemblies 1
A core instrumentation assembly 106 in the furnace is disposed in the corner water gap G formed by the furnace 04, and a neutron detector 108 is provided in an instrumentation tube 107 in the furnace instrumentation assembly 106.
Are discretely arranged at several places in the core axis direction. The neutron detectors 108 are of a so-called fixed type. In a boiling water reactor (BWR), four neutron detectors are usually arranged at equal intervals in the active fuel portion in the core axis direction.

[0005] Further, a TIP
(Traversing In-Core Prob
e: Mobile furnace instrumentation) Conduit 109 was placed and the above TIP
One mobile neutron detector (TIP) 1 in conduit 109
10 is provided movably in the axial direction. As shown in FIG. 12, a movable neutron flux measurement system for continuously measuring neutron flux in the axial direction by the indexing device 111, the TIP drive device 112, the TIP control / neutron flux signal processing device 113, and the like is also installed. ing. Reference numeral 114 denotes a penetration unit, 115 denotes a valve mechanism, and 116 denotes a shielding container. The neutron detectors 108 and 110 and the signal processing device 11 (described later) of each of the neutron detectors 108 and 110
The in-reactor instrumentation system 118 includes the control devices 3, 117 and the like.

On the other hand, the fixed neutron detector (LPRM detector) 108 disposed in the furnace is divided into several groups to generate an average signal (APRM signal) for each group. Core 10 based on the signal
The output level of the third output area is monitored. That is, the LPRM detector 108 detects an APR during an abnormal transient event or an accident such as a neutron flux surge.
A reactor that detects the above-mentioned transient event / accident occurrence according to the M signal and rapidly scrams a reactor stop system (not shown) such as a control rod drive mechanism to prevent fuel damage or core damage. It is configured as part of the safety protection system.

By the way, a neutron detector 10 fixed in a furnace is used.
In No. 8, sensitivity changes individually due to neutron irradiation or the like. Therefore, in order to calibrate the sensitivity of each neutron detector 108 at regular intervals during operation, a TIP (mobile neutron detector) 1
10 is operated to obtain a continuous power distribution in the core axis direction, and the sensitivity change of each neutron detector 108 is corrected by the gain adjustment function of the neutron detector (LPRM) signal processor 117. The detection signal S _LPRM detected by the neutron detector 108 is signal-processed via the signal processing device 117 and transmitted to a process computer 120 described later.

A normal process control computer 120 is installed in the BWR for monitoring the operating state and power distribution of the nuclear power plant. This process control computer 12
Numeral 0 includes an in-core instrumentation control device 121 for monitoring and controlling the in-reactor instrumentation system 118, an output distribution calculation device 122 having a physical model of a three-dimensional nuclear thermal hydraulic calculation code, and an input / output device 123. ing. The reactor power distribution calculating device 122 is built in one or more of the process control computers 120 as a program. The reactor power distribution calculation device 122 includes a power distribution calculation module 124.
And an output distribution learning module 125.

Thus, the in-reactor instrumentation system 118
The neutron flux signal obtained by the TIP 10 is processed by the TIP neutron flux signal processing device 113 of the reactor instrumentation system 18 as an in-core instrumentation signal corresponding to the axial position in the reactor core. The power distribution calculation device 12 is controlled via the in-core instrumentation control device 121 of the process control computer 120.
2 is read as a reference output distribution at the time of three-dimensional nuclear thermal hydraulic calculation.

On the other hand, control rod patterns, core coolant flow rates, reactor pressure vessels as various operating parameters representing the operating state of the reactor obtained from the reactor core status data measuring device 126 as the reactor core status data measuring means. Core current state data S _PROCESS (process amount) such as internal pressure, feed water flow rate, and feed water temperature (or core inlet coolant temperature) is read into the current state data processing device 127 and subjected to data processing to calculate reactor heat output and the like. You. The reactor status data S _{PROCESS S} including the calculated reactor heat output is sent to the reactor power distribution calculation device 122 via the in-core instrumentation control device 121 of the process control computer 120.

The reactor core status data measuring device 126 is actually composed of a plurality of monitoring devices. Further, the reactor core current data measuring device 126 is a generic name of a device for collecting process data of various operating parameters of the nuclear reactor, but is illustrated as one measuring device in FIG. 12 for simplification. further,
The current data processing device 127 is the process control computer 120
May be configured as a part of the function.

The detection signal S transmitted in this manner is
_LPRM and core status data S _{PRO CESS}
It is sent to the output distribution calculation device 122 of the process control computer 120. The power distribution calculation device 122 calculates the core power distribution based on the sent core current state data S _PROCESS and the three-dimensional nuclear thermal hydraulic calculation code of the power distribution calculation module 124. Further, the output distribution calculating device 12
2 learns a reference power distribution of the in-core instrumentation data by a learning function of the power distribution learning module 125, and calculates a calculation result (core power distribution) while referring to the reference power distribution.
Is corrected. As a result, the reactor power distribution can be accurately calculated in the subsequent power distribution prediction calculation.

Further, in the conventional in-core instrumentation assembly 106, instead of the mobile neutron detector 110, as shown in a partially cutaway perspective view of FIG.
In some cases, the γ-ray flux is continuously measured in the core axis direction by moving 0A in the core axis direction. Since γ-rays are generated in proportion to the amount of fission in the reactor core 103, the amount of fission in the vicinity can be measured by measuring the γ-ray flux.

By using the movable neutron detector 110 and the γ-ray detector 110A, the dispersion of the detection accuracy of each of the plurality of neutron detectors 8 arranged in the core axis direction is calibrated, and the output in the core axis direction is output. The distribution can be measured continuously.

As described above, in the conventional nuclear reactor instrumentation system 118, the continuous axial power distribution of the reactor core 103 is measured by the mobile neutron detection that constitutes the movable core internal instrumentation apparatus. Relied on the detector 110 and the mobile γ-ray detector 110A.

On the other hand, a mobile (movable) neutron detector 1
10 and the γ-ray detector 110A are connected to at least one neutron detector 110 or γ-ray detector 110A from the outside of the reactor pressure vessel 102 within the TIP conduit 109.
Since the measurement is performed while moving up and down over the entire length (length in the axial direction of the core) of 3, the mechanical drive operating device for moving and operating the neutron detector 110 and the γ-ray detector 110A becomes large, and the structure becomes large. There was a problem that the operation was complicated and maintenance was complicated. In particular, the detector driving device 112 for moving and operating the neutron detector 110 and the γ-ray detector 110A, TI
Indexing device 111 for selecting P conduit 109, valve mechanism 1
15. It is necessary to maintain the mechanical drive operation device such as the shielding container 116, and since the mobile detectors 110 and 110A are activated, the maintenance management work is a work involving the possibility of exposure. ing.

From this viewpoint, there is a need for a method of monitoring the operating state of the reactor and the power distribution in the axial direction of the reactor core without using a mobile measuring (instrumentation in the reactor) apparatus in the reactor instrumentation system. .

The in-core instrumentation assembly 106 used in the conventional in-core reactor instrumentation system usually includes four fixed neutron detectors 108 and one mobile neutron detector (TI).
P) 110 or a hollow conduit (TIP conduit 109) that movably houses a mobile γ-ray detector 110A and a mobile neutron detector (mobile γ-ray detector), but is fixed in place of the TIP 110. It is being considered to dispose a gamma ray heat detector of the type in the same manner as the fixed neutron detector 108.

Further, a number of γ-ray heat detectors (GT, G
An in-reactor instrumentation system in which a T-detector is disposed has been devised. When measuring the power distribution in the reactor using a large number of fixed γ-ray heat detectors (GT detectors), a part of the large number of GT detectors is arranged close to the LPRM detector. This makes it possible to adjust the sensitivity and gain of the LPRM detector with the GT detector, and to use a mobile neutron detector or a mobile gamma ray detector as a means for measuring core axial power distribution from the characteristics of the GT detector with a small bias change. GT with multiple GT detectors arranged in the axial direction instead of
It has been proposed to be replaced by aggregates.

[0020]

SUMMARY OF THE INVENTION A gamma-ray heat detector (GT detector) used in a conventional instrumentation system in a nuclear reactor.
Uses a differential thermocouple as a method for detecting the temperature of γ-ray heat generation, so there is little change over time. And a saturation phenomenon after a certain core residence time (core loading time). Therefore,
Using a heater built into a gamma thermometer (GT) assembly composed of a plurality of GT heat detectors, the sensitivity of each GT detectorＧsensitivity constant; the thermocouple output voltage of each GT detector and Γ-ray calorific value per unit weight (unit:
W / g) is measured, and the value of the measured sensitivity is checked.
It is necessary to calculate the γ-ray heating value of the GT detector from the thermocouple output voltage signal using the new sensitivity constant.

In this specification, the sensitivity of each GT detector is measured using the above-described processing, that is, using a heater, and when the sensitivity change corresponding to the measurement result exceeds a certain level, the sensitivity is measured. The process of setting a new sensitivity constant for correcting (calibrating) the change is referred to as “sensitivity calibration process”.

The GT signal output from the GT detector during the sensitivity calibration processing is bypassed and is not used for the output distribution measurement processing. It should be noted that the GT detector or the GT assembly which is not used in the sensitivity distribution obtaining process as described above or which is used for the output distribution measuring process of the detector showing abnormal sensitivity determined to be faulty is bypassed. It is called a GT detector or GT aggregate.

Further, the actual sensitivity of the GT detector in the output voltage sensitivity calibration process using the built-in heater of the GT assembly is measured from the increase in the voltage signal of the thermocouple due to the additional heating of the GT detector.

On the other hand, during the measurement of the power distribution inside the furnace using the GT assembly, the power of the core and the power distribution inside the furnace may be steady for a certain time or more (about one hour or more when the gamma decay series is almost in equilibrium). It is necessary from the principle of measuring gamma ray heating.

In the BWR, the process control computer has a BWR3
Built-in 3D simulator, calculates core power distribution periodically or as needed using parameters of core current data such as reactor pressure, core heat output, core coolant flow rate, control rod pattern, etc. Make sure the fuel meets the restrictions.

If the power distribution in the reactor changes relatively short time (within about one hour) before the calculation of the core power distribution on a regular basis, for example, due to a change in the control rod pattern or a large change in the core coolant flow rate. , LPRM detector can immediately output a neutron flux signal corresponding to a change in output distribution. However, the signal of the GT detector (GT signal) does not reach a more accurate signal level until a required time, for example, one hour or more, because the delayed component of the gamma ray source slowly changes.

Accordingly, the power distribution learning correction processing or the LPRM detector sensitivity / gain adjustment processing based on the GT signal cannot be performed until the GT signal has an accurate signal level. LPRM
The detector sensitivity / gain adjustment processing could not be performed periodically (every time) or at any time.

The present invention has been made in view of the above circumstances, and compensates for the delayed gamma effect of the GT signal even when the GT signal level of the GT detector is in an unbalanced state due to the effect of the delayed gamma. And an in-furnace instrumentation signal processor for obtaining a GT signal corresponding to the instantaneous gamma response in a short period of time, and adjusting the sensitivity or gain of the LPRM detector periodically or as needed, and calibrating the LPRM signal. It is an object of the present invention to provide an in-core instrumentation system for a nuclear reactor capable of accurately calculating an in-reactor power distribution using a value or a predicted equilibrium value of a GT detector.

[0029]

In order to achieve the above-mentioned object, an in-core instrumentation signal processing apparatus according to the present invention has a local power distribution in an output region in a nuclear reactor. In the in-furnace instrumentation signal processing device for processing the γ-ray heating value (gamma thermometer signal) detected as, the delayed gamma component included in the detected gamma thermometer signal is represented by its time constant and weight. Means for removing a delayed gamma component represented by a constant and a weight from the gamma thermometer signal to obtain a gamma thermometer signal free from the influence of the delayed gamma component.

In order to achieve the above-mentioned object, an in-core instrumentation signal processing apparatus according to the present invention provides a gamma ray detected as a local power distribution in an output region in a nuclear reactor. In the in-furnace instrumentation signal processing device for processing the calorific value (gamma thermometer signal), when the detected gamma thermometer signal is R (t), the gamma thermometer signal R (t) is converted to an instantaneous response. Using the component term P (t) and the sum of the product of the exponential damping weight and the instantaneous response term of each time constant τ _m having a plurality of time constants τ _m integrated from the past to the present time, formula

[Equation 19] However,

(Equation 20) And a means for compensating for a delay of delayed gamma of the gamma thermometer signal based on equation (1).

According to a third aspect of the present invention, there is provided an in-core instrument signal processing apparatus according to the present invention, wherein a gamma ray detected as a local power distribution in a power region in a reactor is provided. In the in-furnace instrumentation signal processing device for processing the calorific value (gamma thermometer signal), when the detected gamma thermometer signal is R (t), the gamma thermometer signal R (t) is converted to the gamma thermometer signal. Instantaneous response component term P including delayed components up to the thermal time constant of the thermometer
(T) and a plurality of time constants τ _m that are longer than the thermal time constant of the gamma thermometer, and the product of the exponential damping weight and the instantaneous response term of each time constant τ _m is determined from the past. Using the sum integrated up to this point and

(Equation 21) However,

(Equation 22) And a means for compensating for the delay of the delayed gamma of the gamma thermometer signal based on the equation (3). Means for performing the delayed gamma delay compensation calculation using the time constants up to.

According to a fourth aspect of the present invention, there is provided a reactor instrumentation signal processing apparatus according to the present invention, wherein a gamma ray detected as a local power distribution in a power region in a reactor is provided. In the in-furnace instrumentation signal processing device for processing the calorific value (gamma thermometer signal), when the detected gamma thermometer signal is R (t), the gamma thermometer signal R (t) is converted to the gamma thermometer signal. Instantaneous response component term P including delayed components up to the thermal time constant of the thermometer
(T) and a plurality of time constants τ _m that are longer than the thermal time constant of the gamma thermometer, and the product of the exponential damping weight and the instantaneous response term of each time constant τ _m is determined from the past. Using the sum integrated up to this point and

(Equation 23) However,

(Equation 24) And a means for compensating for the delay of the delayed gamma of the gamma thermometer signal based on the equation (6). The exponential decay weight based on a predetermined one time constant within a range of one day or more and one week or less is added as an additional pseudo-term representing a time constant up to about one week and a long time constant of one week or more. This is a means for performing a gamma emission delay compensation operation.

In the in-furnace instrumentation signal processing apparatus of the present invention,
Preferably, the delayed gamma compensating means includes means for removing noise from a gamma thermometer signal (difference thermocouple signal (mV)) from the gamma thermometer by filtering. The delayed gamma delay compensation operation is performed based on the gamma thermometer signal from which noise has been removed, while the gamma thermometer signal is a gamma thermometer set having a thermocouple type gamma ray heat generation detector. The gamma thermometer signal U _c compensated by the late gamma compensation operation of the late gamma compensation means, and the sensitivity S ₀ (mv / (W / W / g)) and the gamma ray heating value _Wc (W / g) of the gamma ray heating detector.
An expression representing g)

W _c = U _c / {S ₀ (1 + αU _c )} (7) where α is the nonlinear coefficient of the thermocouple of the γ-ray heat detector, and the arithmetic processing is performed based on the following equation. _c (W /
g).

In the in-core instrumentation signal processing apparatus of the present invention,
Preferably, as described in claim 6, the gamma thermometer assembly has a built-in heater wire for sensitivity calibration of the γ-ray calorific value detector, and during the sensitivity calibration by the built-in heater wire, that is, During a period from the reception of the heater calibration command to the lapse of a predetermined delay time, the delayed gamma compensation means outputs the output signal (mV signal) of the γ-ray heating value detector immediately before receiving the heater calibration command. ) Is maintained at a constant value, and the delay compensation calculation of the delayed gamma is performed.

In the in-furnace instrumentation signal processing apparatus of the present invention,
Preferably, as described in claim 7, the gamma delay compensating means is expressed by the following equation (8).

(Equation 26) Said gamma thermometer signal R (t) and each -a m _· u m _(t) of the adder and a ₀ by the addition circuit for obtaining the instantaneous response component term P (t) by performing division on the basis of, the added The output P (t) of the circuit is multiplied by a different time constant τ _m to perform integration, and the following equation (9) is obtained.

[Equation 27] Respectively output a plurality of integrator circuits for outputting u _{m (t)} of each of said plurality of output from the integrating circuit a plurality of output signals u _{m (t)} of each inverted -u m _{(t) is} shown in a plurality of inversion circuits and the plurality of each multiplied by a coefficient _{a m} of the formula (8) in respect output from the inverting circuit output signal _{-u m (t) -a m ·} u m (t) the a plurality of coefficient multiplier circuit for obtaining respectively, the said plurality of coefficient multiplying circuits respectively output _{-a m · u m (t)} γ
The delay gamma delay compensation calculation is performed by inputting the measured value R (t) of the linear heat detector to the addition circuit.

In the in-furnace instrumentation signal processing apparatus of the present invention,
Preferably, as set forth in claim 8, the delayed gamma delay compensating means includes a plurality of amplifiers each of which receives and amplifies a plurality of gamma thermometer signals detected by the plurality of γ-ray heat detectors. A plurality of low-pass filter means for respectively removing signal components of a certain frequency or more from output signals of the plurality of amplifiers; and a plurality of signals having a certain frequency or more removed by the plurality of low-pass filter means for a certain period. Signal selection means for sequentially selecting with
Analog-to-digital conversion means for converting a signal selected by the signal selection means into a digital signal; and a digital signal output from the analog-to-digital conversion means corresponding to each of the plurality of γ-ray heat detectors. Gamma thermometer value R _{i, n} corresponding to (t)
(However, i is a value corresponding to each γ-ray heat detector, and n is each γ
Γ as the number of data samplings for each line heating detector)
When the line heat detector is not executing the heater calibration process, the latest gamma thermometer value is updated and stored,
During execution of the heater calibration process, a first data storage unit that does not perform the gamma thermometer value update process, and P _{i, n} (t) corresponding to the P (t) and u _{i, m} (t), respectively. ) And u _{i, m, n} (where i is a value corresponding to each γ-ray heat detector, and n is the number of executions of delay compensation calculation of late gamma) at least two past execution results. 2. data storage means;
Wherein _a m (m = _0~M) and tau _m and the third data storage means for storing (m = 1~M), stored in said first data storage means _{R i, n,} the second P _{i, n−1} , P _{i, n−2} , u _{i, n−} stored in the data storage means of
_1, the lower at u i, _n-2, and the third stored a _m in the data storage _means, tau _m certain calculation cycle while synchronizing the data sampling timing of each γ ray heat detector with Δt By performing the calculations of equations (10) and (11), a value P corresponding to P (t) is obtained for each γ-ray heat detector.
_{i, n} (where i is a value corresponding to each γ-ray heat detector, n
Means for performing the delay gamma delay compensation calculation by digital calculation by obtaining the delay gamma delay compensation calculation execution number.

[0037]

[Equation 28]

(Equation 29) However, initial conditions

[Equation 30] In order to achieve the above object, an in-core instrumentation signal processing apparatus according to the present invention, as described in claim 9, comprises a reactor inside a reactor detected by a detecting means having a thermocouple for detecting γ-ray heating value. Signal S corresponding to the local power distribution in the output region of
An amplification module for amplifying and filtering the thermocouple signal S1 detected by the detection means, and outputting the amplified signal as a first gamma thermometer signal S2; The thermometer signal S2 is input, and the following equations (12) and (13)

(Equation 31)

(Equation 32) , A delayed gamma delay compensation operation for obtaining a second gamma thermometer signal S3 represented by P in the above equations (12) and (13) is performed, and the second gamma thermometer signal S3 is output. A delay compensation module
The first and second gamma thermometer signals S2
And S3 to execute the sensitivity calculation of the γ-ray heater, and convert the signal into a first gamma heat signal W _u without delay compensation and a second gamma heat signal W _c with delay compensation.
A signal control module.

In the in-furnace instrumentation signal processing apparatus of the present invention,
Preferably, as described in claim 10, the GT signal control module is responsive to a command from a process computer or a control device for controlling the in-core instrumentation signal processing device, the first and second GT signal control modules. 2 gamma thermometer signal S
2 and S3 when the first and second gamma thermometer signals S2 and S3
Of the first average gamma thermometer signal S
Means for generating the 2 'and second average gamma thermometer' signal S3 ', and a correction coefficient (S3' / S2 ') determined to match the first average gamma thermometer signal S2'. A second correction gamma obtained by multiplying the second gamma thermometer signal S3 by the correction coefficient until the correction coefficient is stored and a calibration command for the next first and second gamma thermometer signals S2 and S3 is received. Means for calculating a thermometer signal S3B; and a first gamma thermometer signal S2 and a second correction gamma thermometer signal S3B for the process computer in response to a command from the process computer or the control device. And the sensitivity S ₀ (mv / (W
/ W / g)) using the following formula

W = U / {S ₀ (1 + αU)} (14) where at least one of the first gamma thermometer signal S2 and the second correction gamma thermometer signal S3 is U Means for outputting a signal W represented by the following.

In order to achieve the above-mentioned object, the in-furnace instrumentation signal processing device according to the present invention is characterized in that the in-furnace instrumentation signal processing device detects the gamma-ray heating value by detecting means having a thermocouple for detecting the amount of heat generated. And a thermocouple signal S1 corresponding to a local power distribution in a power region in the reactor, wherein the thermocouple signal S1 detected by the detection means is detected.
An amplification module that amplifies and filters the first gamma thermometer signal S2 and outputs the first gamma thermometer signal S2 and the sensitivity S ₀ (mv / (W / W / g) of the γ-ray heat detector. )) Using the following formula

W = U / {S ₀ (1 + αU)} (15) where U is the first gamma thermometer signal S2.
The first gamma heat signal W _u without delayed gamma delay compensation represented by the following formula is obtained, and noise cut processing of the obtained first gamma heat signal W _u is performed, and the noise-cut first gamma heat signal is obtained. W _u and the following equations (16) and (17)

(Equation 35)

[Equation 36] The delay gamma delay compensation calculation is performed based on
6) and (17) and a GT signal control module to obtain the second gamma heating signal W _c that is lag compensation represented by P in, the GT signal control module, process computer or the furnace instrumentation signals when the command from the control unit for controlling the processing apparatus has received h the first and second gamma heating signal W _u and W _c calibration command, the first and second gamma heating signal W _u and W
means for executing a respective average value or moving average value calculation for a predetermined time in _{c to} generate a first average gamma heat signal W _u ′ and a second average gamma heat signal W _c ′;
A correction coefficient (W _c ′ / W _u ′) is _calculated so as to match the first average gamma heat signal W _u ′, and the obtained correction coefficient is stored to store the next first and second gamma heat signals W _u ′. until it receives a calibration command _u and W _c, and means for calculating a second correction gamma heating signal W _{c B} multiplied by the correction coefficient to the second gamma heating signal W _c, from the process computer or control unit Means for outputting at least one of the first gamma heat signal W _u and the second correction gamma heat signal W _c B to the process computer in response to the command.

In order to achieve the above-mentioned object, an in-core instrumentation system according to the present invention includes a plurality of fixed neutrons for detecting a local power distribution in a power region in a nuclear reactor. A detector (LPRM detector) and a fixed γ-ray heat detector of a gamma thermometer assembly for detecting γ-ray heat generation are housed in a furnace instrumentation tube, and the γ-ray heat detector is at least an LPRM detector. , A LPRM signal processing unit for processing a neutron flux detection signal from the LPRM detector, and a gamma thermometer signal from the gamma thermometer assembly. A gamma thermometer heater for controlling in-furnace instrumentation signal processing according to any one of claims 1 to 11 for controlling power supply to a heater built in the gamma thermometer assembly. The gamma thermometer heater control means controls the amount of electric current to be supplied to the built-in heater of the gamma thermometer assembly, and outputs the output voltage of each detector of the gamma thermometer assembly by heating the heater. It has means for performing sensitivity calibration.

[0041]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an in-core instrumentation processing apparatus (also referred to as a gamma thermometer signal processing apparatus or a GT signal processing apparatus) and a fixed in-core instrumentation system according to the present invention. It will be described with reference to FIG.

[First Embodiment] FIG. 1 shows an in-furnace instrumentation signal processing apparatus (GT signal processing apparatus) 1 for processing an in-furnace instrumentation signal such as a gamma thermometer signal according to the present invention, and this GT.
The GT heater control device 2 is closely related to the operation processing of the signal processing device 1. In particular, the in-furnace instrumentation signal processing device is hereinafter abbreviated as the GT signal processing device.

The GT signal processing device 1 comprises a GT signal field board 3, a GT control board 4, and a communication circuit therebetween.

That is, the GT signal spot panel 3 includes a plurality of G signals.
It has a terminal for taking in a signal (gamma thermometer signal) S1 from the T sensor (differential thermocouple) 21 and a plurality of γ-ray heat detectors (GT) taken in through these terminals.
Sensors 2) for amplifying the gamma thermometer signal (GT signal) S1 from the sensor 21
1, a plurality of amplifiers 22, a noise cut filter 23 provided on the signal downstream side of each amplifier 22, and a plurality of GT sensors amplified and noise cut through each amplifier 22 and each filter 23. A multiplexer 24 which samples the gamma thermometer signal S1 from the high-speed sampling unit 21 at high speed at a constant period to form one signal sequence.
And an analog / digital converter (A / D converter) 2 for converting the gamma thermometer signal S1 sequentially output from the multiplexer 24 into a digital signal.
5, the amplifier 22, the filter 23,
The GT signal amplification module 26 is configured by the multiplexer 24 and the A / D converter 25.

The GT signal field board 3 includes a signal processor (DSP) 30 for digital signal processing, a memory 31M for storing programs, data, and the like necessary for processing of the signal processor 30, and a signal holding for signal holding. The DSP 30, the memory 31 </ b> M, and the signal holding circuit 32 constitute a delayed gamma compensation module 33. Further, the GT signal site panel 3 includes an input / output buffer 35 for temporarily holding input / output data between the GT signal site panel 3 and the GT control panel 4.

GT heater control device (GT heater control panel)
Although not shown in FIG. 2 (153 in FIG. 6), a power supply, a power supply control circuit, a heater current measurement circuit, an applied voltage measurement circuit, a measurement current signal and an analog / digital converter for the measurement voltage signal are provided inside. ing. Further, the GT heater control device 2 has an input / output device 37 for data input / output.

On the other hand, the GT control panel 4 has a CP for control processing.
U42, a memory 42M for storing programs and data necessary for the processing of the CPU 42, and a GT control panel 4
Transmitter 44 for data transmission between the transmission and GT signal field panel 3
A display / input / output console (display console) 45 for displaying processing data of the CPU 42 and inputting / outputting data (instructions, etc.) by manual operation of an operator (operator); and other components such as the GT control panel 4 and the process computer. An input / output buffer 46 for temporarily holding input / output data between computers is provided.

Further, an optical cable 53 and a transmitter 52 for transmitting / receiving (communicating) signals (data) between the GT signal field panel 3 and the GT control panel 4 are provided.

Next, the operation and operation of the GT transmission site panel 3 will be described.

A plurality of voltage signals (mV; GT sensor signals, G) output from a plurality of GT sensors (differential thermocouples) 21
The T signal (S signal) S1 is amplified by the amplifier 22 and then noise-cut by a filter (low-pass filter) 23 to reduce noise due to sampling. The plurality of noise-cut GT signals S1 are sampled by the multiplexer 24, and are sequentially selected and output at a constant cycle.

GT signal (analog signal) selectively output
S1 is converted into a digital signal S2 by an analog / digital converter 25, and the converted digital signal S2
Is transmitted to the input / output buffer 35 and the delayed gamma compensation module 33 together with an address signal ( _LS2 ) representing the address of the corresponding GT sensor 21.

Here, the operation and operation of the delayed gamma compensation module 33 will be described with reference to FIG.

That is, the analog / digital converter 2
The GT signal S2 digitally converted in 5 is branched into two, and one of the branched GT signals S2 is sent to the signal holding circuit 32 together with the GT sensor address signal ( _LS2 ).

The signal holding circuit 32 receives C through a signal circuit.
The PU sensor 42 (L _S2 ) of the GT sensor 21 (L
_S2) is to obtain a signal representative of whether or not the heater calibration with the sensor address signal _{(L S2CPU),} address _{L S2} and L
A logical determination is made as to whether the _S2CPU matches.

As a result of the above logical judgment, the addresses L _S2 and L _S2
If the heater calibration in-progress signal is transmitted when the value matches the _S2CPU , the signal holding circuit 32 does not read the newly transmitted GT signal for the GT sensor (L _S2 ). Is transmitted to the digital signal processor 30 (DSP 30).

On the other hand, if the address L _S2 matches the L _S2CPU and the heater calibration in-progress signal has not been transmitted, the signal holding circuit 32 outputs the GT signal newly transmitted from the GT sensor (L _S2 ). Read and transmit the read new GT signal to the digital signal processor 30. Further, in the case where the address _{L S2} and _{L S2CPU} do not match, signal holding circuit 32 reads the new GT signal for GT sensors _{(L S2),} and transmits the new GT signal to the digital signal processor P30.

At this time, the digital signal processor 30
Has a plurality of time constants from ten seconds or more, for example, several tens of seconds to about one day of late gamma rays in the form of a difference equation after digitally filtering the time series signal of the GT signal S2 firstly. By compensating for the delayed gamma effect, a GT signal S3 close to the heating response by the instantaneous gamma ray is obtained. Then, the digital signal processor 30 transmits a GT sensor address signal ( _LS3 ) indicating the address of the GT sensor corresponding to the result to the GT control panel 4.

The digital signal processor 30 reads, from the memory 31M, fixed data to be used for the calculation (late gamma effect compensation calculation), and writes the intermediate calculation processing result for each GT sensor to the memory 31M. The data is read out in response.

The signal temporarily held in the input / output buffer 35 is read by the transmitter 52, where it is multiplexed with data from another board, converted into an optical signal, and converted into an optical signal.
It is transmitted at 3.

The operation and function of the GT heater control panel 2 will be described with reference to FIG. The GT heater control panel 2 receives a GT heater calibration command accompanied by a GT assembly address designation from the GT control panel 4 via the transmitter 32, and thereby the heater wires 27 of the GT assembly.
Is selected and energized, the voltage is controlled so that a predetermined heater current flows, and the heater current and applied voltage are measured. And
The GT heater control panel 2 converts the heater current measurement signal and the applied voltage measurement signal obtained by the above measurement into a digital signal by an analog / digital converter (A / D converter), and converts the signal into an input / output device (I / O) 37. Send to

The transmitter 52 reads the heater current measurement signal, the applied voltage signal, and the GT heater address signal transmitted to the input / output device 37, multiplexes the read data with a signal (data) from another board, and multiplexes the read data. The converted signal is converted into an optical signal and transmitted to the GT control panel 4 via the optical cable 33.

The detailed operation and action of the GT control panel 4 are shown in FIG.
This will be described more clearly with reference to the functional block diagram of FIG.
In this block diagram, one GT sensor 21
GT heater signal and one GT signal only
Is shown in the block diagram, but the heater address signal is actually
(L_H), GT sensor address signal (L_S2) And (L
_S3) Handles multiple heater signals and GT signals
Configuration.

The transmitter 44 of the GT control panel 4 is
Is converted into an electric signal, separated into various signals and transmitted. That is, the heater current measurement signal (I _H ), the applied voltage signal (V _H ), and the heater address signal (L _H ) are transmitted to the CPU 42, and the delayed gamma compensation no signal S2 and the delayed gamma compensation are provided as GT signals. The signal S3 obtained is also the GT sensor address ( _LS2 ) of each signal.
And ( _LS3 ) are transmitted to the CPU 42.

The CPU 42 mainly performs the following (1)
To (6), and execute the processing functions of (1) to (6).

That is, the CPU 42 executes the GT signal S2 not delayed gamma-corrected as the processing function (1).
(Indicated by U in the formula (18)) uptake with GT sensors Address _{(L S 2),} the GT sensor address (L
GT sensor sensitivity _S 0 corresponding to _S2) (mV / (W /
g)) and the nonlinear coefficient α (mV ⁻¹ ) are stored in the memory 42M.
S ₀ , α and the following equation (18)

The GT signal S2 (thermocouple signal) is converted into a gamma heating amount S4A (W / g) (W in the above equation (18)) based on W = U / {S ₀ (1 + αU)} (18) In the display)
Convert to Then, the converted result is input / output buffer 4
Send to 6.

As a processing function of (2), the CPU 42 fetches the GT signal S3 which has been subjected to delayed gamma correction together with the GT sensor address ( _LS3 ), and receives the GT sensor address ( _LS3 ) corresponding to the GT sensor address ( _LS3 ). Sensitivity S ₀ (mV /
(W / g)) and the nonlinear coefficient α (mV ⁻¹ ) are read from the memory 42M. Then, the CPU 42 converts the thermocouple signal S3 of the GT sensor into a gamma heating amount S4B based on the read S ₀ and α and the above equation (18), and sends the converted result to the input / output buffer 46.

Further, the CPU 42 includes a process computer (not shown) to the GT control panel 4 as a processing function (3).
Device (control device) for controlling the in-core instrumentation control device (not shown)
Or a heater calibration command transmitted from the operator (or a technician in charge of the furnace) through the input / output buffer 46, or the operator via the display console 45 of the GT control panel 4. (Or a technician in charge of the in-furnace instrument) instructs the transmitter 44 to issue a heater calibration instruction and its corresponding address (L
_H ).

In parallel with the heater calibration instruction, the CPU 4
2 is a GT signal S included in the heater calibration target GT assembly.
2 (signals that have not been delayed gamma-compensated) are collected at high frequency, and a plurality of signals in the state of only gamma ray heating before additional heating by the heater of the GT assembly are collected, and further heated by the heater. A plurality of signals when the signals are in the equilibrium state are collected, and the average value of the signals in the state of only the gamma ray heating and the average value of the signals in the equilibrium state are obtained and stored in the memory 42M.

Similarly, the CPU 42 sets the heater calibration target G
The current value signal and the voltage value signal of the equilibrium state during energization of the heater for the T-assembly are transmitted to the I / O 37 of the GT heater control panel 2,
The data collected via the transmitter 52 and the transmitter 44 and stored in the memory 4
Store in 2M. The CPU 42 includes transmitters 44, 5
GT signal field board 3 via 2 and input / output buffer 35
Of the GT sensor address for which the heater is being calibrated is output to the signal holding circuit 32 of the delayed gamma compensation module 33, and the signal is cleared after the heater calibration is completed.

The CPU 42 executes the processing function (4) (related to the processing function (3)) as the memory 42M.
The average signal of the GT sensor before and after the heater is stored in the memory 42M, the GT sensor mass for heater calibration and the heater resistance stored in advance in the memory 42M for each GT sensor address.
From the non-linear coefficient α, data (GT sensor mass, heater resistance, non-linear coefficient α) corresponding to the address of the GT sensor to be calibrated is read out, and disclosed in Japanese Patent Application No. 11-2230.
18 (2) Equation “S ₀ = [{U ′ / (1 + αU ′)} −
{U / (1 + αU)}] / P _H ; U: Output signal (mV) before heating the built-in heater, U ′: Output signal (mV) when heating the built-in heater, P _H : Additional heat generated by the built-in heater in (W / g) "in the indicated operations, and calculates the new GT sensor sensitivity _{S 0.} Incidentally, GT sensor sensitivity S ₀ calculated in temporarily memory 42M, can be stored in another area that is not used in the calculation process of the processing functions (1) and (2).

The CPU 42 transmits the obtained new sensitivity S ₀ to a process computer or a control device (not shown), and receives an update confirmation operation of an operator or an in-core instrumentation system engineer for the new sensitivity S ₀ (or automatically performs the operation). ), The memory 42M used for the calculations of the processing functions (1) and (2)
Write to the area.

The CPU 42 performs the processing function of (5) in response to a command transmitted through the display console 45 or a command transmitted from a process computer, a control device, or the like. It is also possible to write and update the nonlinear coefficient α, S ₀ , sensor mass, sensor heater resistance, etc. for each sensor.

Further, when the CPU 42 receives the GT signals S2 and S3 calibration commands transmitted from the process computer or the control device via the input / output buffer 46 as the processing functions of (6), the CPU 42 The average values or the moving average values of the GT signals S2 and S3 received by the processing operation of (2) for a predetermined time are calculated to generate the GT average signals S2 ′ and S3 ′, and the GT average signals S2 ′ are generated. A correction coefficient (S3 '/ S2') is determined so as to match. Then, the obtained correction coefficient (S3 '/ S2') is stored in the memory 42M, and until the GT signal S2 and the S3 calibration command are received next, the correction coefficient (S3
3 ′ / S2 ′), and calculates a corrected GT signal S3B signal, and according to a command transmitted from the process computer or the control device via the input / output buffer 46, outputs the GT signal S2 and the corrected GT signal S3B. Using at least one and the sensitivity S ₀ (mv / (W / W / g)) of the GT sensor, the above-mentioned equation (18): W = U / {S ₀ (1 + αU)}; A signal W expressed by U as at least one of the GT signals S3B is output to the process computer.

On the other hand, the GT heater control panel (device) 2
In accordance with the heater calibration command transmitted from the T control panel 4 via the transmitter 44 and the like, the commanded heater calibration target G
The T-assembly is selected, the heater energization control is performed based on a preset timer, and the current value and voltage value of the heater while the heater is energized are measured. And GT heater control panel 2
Is the heater signal representing the address L _H in the calibration (heater address signals (L _H), the applied voltage signal V _H indicating a heater current measuring signal I _H and the applied voltage value representative of the measured current
Is transmitted to the GT control panel 4.

Here, the method of compensating for the delayed gamma of the GT signal will be described in more detail.

The gamma ray heating detected by the GT sensor is caused by both the prompt gamma ray generated when the fuel around the GT sensor fission and the delayed gamma ray emitted when many types of fission products generated by fission decay. by. The delayed gamma rays associated with this decay have many time constants and their weights.

The data of the delayed component and the prompt component of such gamma rays are obtained from nuclear data, and a further integrated data thereof has been clarified by a study of the decay heat of fission products. According to this study,
Decay heat includes both β-rays and gamma rays, and among them, an approximate expression of 31 terms is disclosed as the following equation (19) as being due to gamma rays.

[0078]

(38) Here, as an approximate expression of f (t),

[Equation 39] Has been proposed. When the equation (20) is inserted into the equation (19), the term of prompt gamma rays is added, and only the gamma ray heating during the reactor operation is considered, the term of the cooling time can be ignored as 0 second. Therefore, the energy R (t) given to the GT sensor for gamma rays can be rewritten in the following equation (21) (variables are redefined).

[0079]

(Equation 40) Here, assuming a sufficiently long value for the time integral of t is tau _m equation (21), reposition the 0 to -∞. Further, the fission rate P (t) is defined as a function when all the gamma heatings are virtually immediate components, and the function P (t) is actually a gamma heating by a combination of first-order lag functions having a number of time constants. And R (t) = P (t) when the output is constant for a sufficiently long time in the steady state.
R (t) is given by the following equation (22)

[Equation 41] That is, according to equation (22), the GT signal R (t) is
Expressed by using an instantaneous response component term P (t), and integrating the sum has a plurality of time constants tau _m the product of microphone spot Exponential damping weight and instantaneous response section each time constant tau _m from the past to the present time be able to.

Here, the actual GT sensor has a time constant of about several tens of seconds before a signal is output as a thermocouple voltage by gamma heating, and the actual GT signal (GT signal) is a local output which competes for several seconds. It is not the purpose of capturing the change of the gamma response, but when measuring the local output after a steady state for a few minutes or more with a GT sensor, for example, the influence of the delayed gamma response based on the past history before the steady state is affected. The purpose is to get rid of it. Therefore, the term of the time constant shorter than ten and several seconds is added to the prompt component term and re-added, and the one with the long time constant is ignored because its weight is small, and as a result, the time constant term is about ten seconds or more to about half a day. For example, in the present embodiment, M is set to about 10 (If the value of M is not reduced, the amount of calculation performed by the DSP 30 increases, and the accuracy of one GT sensor does not significantly change even though the accuracy does not change so much. Only the time of the late gamma compensation calculation will increase).

Considering the future large load following operation, for example, 50% output on weekends, or even lower
%, The effect of the time constant term longer than half a day appears to be small, but as a countermeasure, 1
The pseudo long term (additional pseudo term) having an appropriate time constant within the range of about a week is weighted by adding the contribution of the time constant longer than that time constant (weighting the exponential decay weight). If added, late gamma rays can be compensated even during operation with a relatively long operation time during the above-mentioned large output fluctuation.

Further, the delayed gamma ray compensation calculation method executed by the DSP 30 will be described in detail. In addition,
Actually, the late gamma compensation calculation is performed for each GT sensor, so the DSP 30 stores the intermediate calculation result in the memory 31M for each GT sensor and uses it for the calculation of the next time step. It has become. For simplicity, only one GT sensor is described here, and the suffix indicating each sensor is omitted.
Moreover, constant tau _m, the weight a _m when delayed gamma rays, use the same value for all the GT sensors. Furthermore, it is conceivable to prepare a plurality of these constants in consideration of the effect based on the change in the composition of the isotope fissioned due to the burnup of the fuel around the GT sensor. , Fixed.

The above equation (22) is obtained by the following equations (23) and (2)
It can be simplified as shown in 4).

[0084]

(Equation 42)

[Equation 43] Here, the time derivative of equation (23) gives:

[Equation 44] When the above equation (25) is rewritten as a difference equation,

[Equation 45] The subscript n for R indicates the number of data samplings for each γ-ray heat detector, and the subscript i (i = 1, 2,...) Indicating a value corresponding to each of the omitted GT sensors.
·), The GT signal of each GT sensor is R _{i, n}
It is expressed as

[0085] Also, shaped n subscript for P (t) and _u m (t) represents the delayed gamma lag compensation execution times.

The above equation (26) is a difference equation of the simultaneous equations.

[Equation 46]

[Equation 47] It is expressed as

[0087] In a state where sufficient equilibrium state is continued for a long time, with R (t) = P (t ) = Const ( constant), _{u m}
(T) = P (t) (m = 1 to M). Further, in the initial startup _{state, R (t) = P (} t) = u m (t) = 0 (m
= 1 to M).

An operator (or the inside of the furnace)
Initial value setting command issued by the instrumentation system engineer), DS
When performing initialization of P30, the CPU 42
The first difference equation used at the time of the initialization stored in advance in 1M
The initial condition is read in accordance with the initial condition state. Sand
In the initial startup, R_n-1= P_n-1= U_{m
, N-1}= 0 (m = 1 to M), and a sufficient equilibrium state
If so, P _n-1= U_{m, n-1}= R
_n-1(M = 1 to M). (Where R_n-1Is
The CPU 42 determines the signal S2 that has not been delayed gamma-compensated.
This is a value determined by time averaging).

From the above, R (t) is set to DSP3 shown in FIG.
When read again as S2 of the GT signal input to 0, DSP3
0, using the above equations (27) and (28) and the initial condition, the delayed gamma-compensated GT signal S3 (the above equation (27)
In (28), P _n ) can be calculated.

Note that a used in the above-mentioned delayed gamma compensation calculation
_m, the value of tau _m is stored in advance in the memory 31M, D
SP30 is stored a _m, is adapted to perform a delayed gamma lag compensation calculation based on the value of tau _m. Also,
The DSP 30 executes the delayed gamma delay compensation calculation at a high speed, collects each GT signal at a frequency of, for example, once / second, and subsequently calculates the delayed gamma compensation of each sensor sequentially. The intermediate calculation result is also written into the memory 31M, read out, and operated.

In the present embodiment, the DSP 30 sets G every one second.
The T signal is read, the above-described delayed gamma delay compensation calculation is performed, and the result every second is transmitted to the CPU 42 via the transmission circuit 52 and the like.
However, the present invention is not limited to this. The time constant for performing the delayed gamma delay compensation calculation and the corrected signal (S3) are determined based on the relationship with the time constant of the delayed gamma compensation. Any other time interval may be used as long as the sampling interval is sufficiently short for the time change rate.

During the normal GT heater calibration, the addition due to the heat input of the in-line heater is added to the GT signal and cannot be used as a correct GT signal. However, according to the present embodiment, the signal holding circuit 32 and the CPU 42 GT signal S2 during heater calibration is determined by DSP3
0, the signal holding circuit 3
2 is transmitted to the DSP 30, the accuracy of the late gamma delay compensation calculation can be improved without disturbing the late gamma compensation calculation.

Also, since it is known that the sensitivity S _{0 of the} GT sensor changes during operation, the gamma divided by the sensitivity S ₀ (mV / (W / g)) is used as the delayed gamma delay compensation calculation. When the above-described gamma delay compensation calculation is performed using the signal level S4A of the heating rate (W / g), a disturbance is given to the delayed gamma compensation calculation by the discontinuous signal level S4A. since using (dividing previous sensitivity S ₀₎ GT signal (mV signal) running the gamma lag compensation computation, not disturbed by the sensitivity change, improve the accuracy of the delayed gamma lag compensation operation be able to.

Although the GT signal (mV signal) has an error corresponding to the nonlinear coefficient, its value is usually 1 to 2%.
Since this error is not a rounding error, it is more preferable to compensate for the delayed gamma delay at the mV signal stage when the above-mentioned problem is balanced.

Further, the GT signal S3 which has been delayed gamma compensated
May cause a bias with the GT signal S2 that is not delayed gamma compensated. This bias can occur when the initial value input condition is not in an ideal state and when a slight error occurs in the delayed gamma delay compensation calculation. In order to eliminate the discrepancy between the GT signal S2 and the GT signal S3 in this case, having the function (6) of the CPU 42 is important as a countermeasure against bias in actual operation.

[Second Embodiment] FIG. 4 is a diagram showing the G shown in FIG.
This is a modification of the T signal field panel, and shows a case where the circuit components including the delayed gamma compensation module 33 are configured by analog circuits. Note that FIG. 4 shows only one GT sensor for ease of explanation.

That is, in FIG.
One of the T sensors, 61 is a differential amplifier circuit, 62 is a filter circuit, 63 is an addition circuit, 64a1 to 64a10 are primary delay circuits, 65a1 to 65a10 are integration circuits, 66
a1 to 66a10 are inverting circuits.

The differential amplifier circuit 61 includes one GT sensor 2
Input a voltage signal on the order of 1 to mV, for example, 0 to
It outputs a 5V voltage signal. The filter circuit 62 includes a resistor _{R 6 2,} a low-pass filter composed of the capacitor _{C 62} and the operational amplifier 62A, the cut-off frequency fc
= C ₆₂ × R ₆₂ The noise of the GT signal of ₆₂ or more is removed, and a signal −R having a polarity opposite to that of the output of the differential amplifier circuit 61 is output.

The addition circuit 63 outputs the signal −U of the inversion circuit 63.
1... -Resistor R corresponding to U10 _63a0~ R
_63a10, Resistance R_63afAnd the operational amplifier 63A
And the output of the inverting circuit 63 -U1.
.Resistor R for -U10_63a0~ R_63a10And
And resistance R_63afThe following equation (29) is used to calculate the value of
Do.

[0100]

[Equation 48] Here, when (1 / R _63a0 ) = 1, (1 / R _63a0 )
_63af ) = a0, (1 / R _63am ) = am (m = 1
-10).

The primary delay circuits 64a1 to 64a10 include resistors _{R64a0 to R64a10} and capacitors _R64a0 to _R64a0 .
R _64A10 and are each configured from the operational amplifier 64A, a reverse polarity relative to the output P of the adder 63, the time constant _{τ m = C 64a m × R} 64am (m = 1~
10) output the primary delay signal -Vm (m = 1 to 10).

The integrating circuits 65a1 to 65am are:
It is arranged out of the capacitor _{R 65a0 ~R 65a1 0} and the operational amplifier 65A, first-order lag circuit 64
Each output signal -Vm of a1 to 64a10 (m = 1 to 10)
, The integral shown in the following equation (30) is executed, and Um (m = 1 to 10) is output.

[0103]

[Equation 49] Further, the inverting circuits 66a1 to 66am include two resistors R
_{66a0 ~R 66a1} are arranged out ₀ and the operational amplifier 64A, the integration circuit 65a1~65a10
Inverts the polarity of each output signal Um (m = 1 to 10) to output a signal −Um (m = 1 to 10).

As a result, a delayed gamma delay compensation operation can be performed on the output signal of the GT sensor 21 based on the following equations (31) and (32).

[0105]

[Equation 50] [Third Embodiment] FIG. 5 shows a GT signal processing apparatus 1 according to the present invention.
1 shows an embodiment A.

The present embodiment is a modification of the GT signal processing device 1 in the first embodiment shown in FIG. 1, and the description of the same components and operations will be omitted.

The GT signal processor 1A comprises a GT signal field board 3A, a GT control board 4A, and a communication circuit therebetween.

The difference from the configuration of the first embodiment is that
Whereas the GT signal field board of the embodiment mainly includes a GT signal amplification module and a delayed gamma compensation module, the GT field field board 1A of the present embodiment mainly includes a GT signal amplification module and signal input / output. That is, only the buffer 35 is provided. That is, gamma thermometer signals (GT signals) from a plurality of GT sensors (differential thermocouples) 21
It has a terminal for taking in S1, and GT signals S1 from a plurality of GT sensors 21 taken in through these terminals.
A plurality of amplifiers 22 for amplification, a filter 23 for noise cut provided respectively on the signal downstream side of each amplifier 22, and a plurality of GT signals S1 subjected to amplification and noise cut
Signal amplification module 26 composed of a multiplexer 24 which performs high-speed sampling at a fixed period to form one signal sequence, a GT signal field board 3A and a GT control board 4
An input / output buffer 35 for temporarily holding input / output data between A and A is provided.

The GT control panel 4A is provided with a control processing CPU 42.
A, a memory 42MA for storing program data,
A transmitter 44 for data transmission, and a display / input / output console (display console) 45 for displaying processed data of the CPU 42A and inputting / outputting data (instructions, etc.).
And an input / output buffer 46 for temporarily holding input / output data.

Further, an optical cable 53 and a transmitter 52 for transmitting and receiving signals (data) between the GT signal field panel 3A and the GT control panel 4A are provided.

Since the configuration and operation of the GT heater control panel 2 are the same as those of the first embodiment, the description is omitted.

First, the operation and action of the GT signal spot panel 3A will be described.

A plurality of voltage signals (mV signals; GT signals) S1 output from a plurality of GT sensors (differential thermocouples) 21
Is amplified by the amplifier 22 and then filtered (low-pass filter) to reduce noise due to sampling.
The noise is cut at 23. The plurality of noise-cut GT signals S1 are sampled by the multiplexer 24, and are sequentially selected and output at a constant cycle.

GT signal (analog signal) selectively output
S1 is converted into a digital signal S2 by an analog / digital converter 25, and the converted digital signal S2
Is transmitted to the input / output buffer 35 and temporarily stored. The digital signal S2 temporarily stored in the input / output buffer 35 is read by the transmitter 52, converted into an optical signal, multiplexed by the optical cable 53, and transmitted.

At this time, the difference between the GT control panel 4A and the first embodiment is that the GT signal S3 and the GT sensor address signal (L) in the functional block diagram shown in FIG.
_S3 ) does not exist as an input signal of the CPU 42. Note that, in this block diagram, one GT
Although only the GT heater signal and one GT signal output from the sensor 21 are shown in the block diagram, actually, the heater address signal (L _H ) and the GT sensor address signal (LS ₂ )
And (in the Figure 5 _{configuration, L S3} is not present) _{(L S3)} by a configuration to handle multiple heaters signals and GT signal.

That is, the transmitter 44 of the GT control panel 4A
Converts an optical signal sent from the transmitter 32 into an electric signal, separates the signal into various signals, and transmits the signals. That is, the heater current measurement signal (I _H ), the applied voltage signal (V _H ), and the heater address signal (L _H ) are transmitted to the CPU 42A, and the delayed gamma compensation no signal S2 is also provided as a GT signal.
Along with the GT sensor address ( _LS2 ) of the signal, the CPU 4
2A.

The CPU 42A mainly has the following processing functions (1) to (6).
The processing function of (6) is executed.

That is, the CPU 42A executes the process (1)
As a function, the GT signal S2 that has not been delayed gamma corrected
(Indicated by U in the following equation (18)) is the GT sensor address
(L _S2) And the GT sensor address (L
_S2GT sensor sensitivity S corresponding to)₀(MV / (W /
g)) and the nonlinear coefficient α (mV^-1) To the memory 42M
Read from A, read S₀, Α and the formula “W = U
/ ｛S₀(1 + αU)｝ ”, the GT signal S2
(Thermocouple signal) to gamma heating amount (gamma heating signal, gun
Heat generation signal, GT signal S4A (W / g))
To W). Then, enter and exit the converted result
To the output buffer 46.

Further, the CPU 42A executes a delayed gamma compensation operation of the gamma heat generation signal S4A with reference to the memory 42MA as the processing function of (2).

That is, the CPU 42A outputs the GT signal S2
The stored with GT sensors address signal _{(L S2)} read in the memory 42 mA. Then CPU42A is, GT sensor at the address corresponding to the GT sensor address signal _{(L S2) (L S2)} it is judged whether or not in the heater calibration memory sensor address signal of GT sensors in the heater calibration _{(L S2CPU)} Write to 42MA. Then, CPU 42a performs whether the logical decision and addresses _{L S2} and _{L S2CPU} match.

As a result of the logical judgment, the addresses L _S2 and L
_{If the S2CPU} matches and the heater calibration in-progress signal is transmitted from the GT heater control panel 2, for example, G
GT signal transmitted newly for the T sensor (L _S2) is not read, reading the last GT signal before the previous heater calibration from the memory 42 mA.

On the other hand, if the address L _S2 matches the L _S2CPU and the heater calibration in-progress signal has not been transmitted, the CPU 42A reads the newly transmitted GT signal for the GT sensor (L _S2 ). Further, in the case where the address _{L S2} and _{L S2CPU} do not match,
CPU42A reads a new GT signal for GT sensors _{(L S2).}

Then, the CPU 42A first digitally filters the time series signal of the GT signal S2 by a first-order lag method, and then, in the form of a difference equation, from ten seconds or more, for example, several tens seconds to about one day of a delayed gamma ray. By compensating for the delayed gamma effect having a plurality of time constants, a GT signal S3 close to the heating response by instantaneous gamma rays is obtained. Then, CPU 42a is obtained results GT sensor address signal representing the address of the corresponding GT sensor _{(L S3)} and stored in the memory 42 mA, further delayed gamma effects compensate for fixed data memory 42M used for calculation Read from. The intermediate calculation processing result for each GT sensor is written in the memory 42M and read as needed.

Next, as the processing function of (3), the CPU 42A converts the late-gamma-corrected GT signal S3 (denoted by U in the following equation (33)) calculated by the processing operation of (2) into GT. sensor address incorporation with _{(L S2),} GT sensor sensitivity _S 0 corresponding to the GT sensor address _{(L S2) (mV / (} W / g)) and non-linear coefficient α
(MV ^-1 ) is read from the memory 42M, and the read S ₀ , α and the following equation (33)

The GT signal S3 (thermocouple signal) is converted into a gamma heating amount (heating signal, heating signal) S4B (W / g) based on the following equation: W = U / {S ₀ (1 + αU)} (33) (W in the above equation). Then, the converted result is sent to the input / output buffer 46.

Next, as a processing function of (4), the CPU 42A executes an automatic or operator operation from a process computer (not shown) to the GT control panel 4A, a device (control device) for controlling the in-core instrumentation control device (not shown), or the like. (Or a technician in charge of the in-furnace instrument) and a heater calibration command sent via the input / output buffer 46 via the input / output buffer 46, or an operator (or a person in charge of the in-furnace instrument) via the display console 45 of the GT control panel 4A. In response to a heater calibration command input by a technician), a heater calibration command and its corresponding address (L _H ) are transmitted to the transmitter 44 to perform heater calibration on the GT assembly to be calibrated.

In parallel with the heater calibration instruction, the CPU 4
2A is a state in which the GT signal S2 (a signal not delayed gamma-compensated) included in the GT assembly to be calibrated for the heater is frequently collected, and only the gamma ray heating before the additional heating by the heater of the GT assembly is performed. , And a plurality of signals when the signals are equilibrated by being heated by the heater, and the average value of the signals in the state of only gamma ray heating and the average value of the signals in the equilibrium state are respectively obtained. Then, it is stored in the memory 42MA.

Similarly, the CPU 42 sets the heater calibration target G
The current value signal and the voltage value signal of the equilibrium state during energization of the heater for the T-assembly are transmitted to the I / O 37 of the GT heater control panel 2,
The data collected via the transmitter 52 and the transmitter 44 and stored in the memory 4
Store in 2MA. Further, the CPU 42A writes a signal indicating that the heater is being calibrated to the memory 42MA for the GT sensor address where the heater is being calibrated, and clears the signal after the completion of the heater calibration.

Then, the CPU 42A executes the processing unit of (5).
No. (related to the processing function of (4))
Average signal of GT sensor before and after heater heating stored in MA
Number and the GT sensor address in the memory 42MA in advance.
GT sensor mass for heater calibration and heater resistance
The GT calibration target GT sensor is selected from the resistance and nonlinear coefficient α.
Data (GT sensor mass, heater
Resistance and nonlinear coefficient α) are read out and disclosed in Japanese Patent Application No. Hei 11-223.
018 (2) Expression “S₀= [{U '/ (1 + αU')}-
{U / (1 + αU)}] / P_H; However, U: Built-in heater
Output signal (mV) before heating, U ': when heating built-in heater
Output signal (mV), P_H: Additional heat generated by the built-in heater
(W / g) ", the new GT sensor
Sensitivity S ₀Is calculated. In addition, the calculated GT sensor sensitivity
S₀Is temporarily stored in the memory 42MA.
Another area that is not used for the arithmetic processing of (3) and (4)
It is also possible to store it in the area.

The CPU 42A transmits the obtained new sensitivity S ₀ to a process computer or a control device (not shown), and receives an update confirmation operation of the operator or the in-core instrumentation system technician for the new sensitivity S ₀ (or automatically performs the operation). ), The memory 42 used for the calculation of the processing functions (3) and (4)
Write to MA area.

In addition to the above functions, the CPU 42A
As the processing function of (6), the display console 45
, Or a non-linear coefficient α, S ₀ , a sensor unit mass, a sensor unit heater resistance value for each GT sensor stored in the memory 42MA in response to a command transmitted through the microcomputer or a command transmitted from a process computer, a control device, or the like. Etc. can be written and updated.

Further, the CPU 42A executes the GT signals S2 and S3 transmitted from the process computer or the control device via the input / output buffer 46 as the processing function of (7).
When the calibration command is received, the average value or the moving average value of the GT signals S2 and S3 obtained by the processing operations (3) and (4) is calculated for a predetermined period of time to execute the GT average signal S2 ′. And S3 'are created, and a correction coefficient (S3' / S2 ') is determined so as to match the GT average signal S2'. Then, the obtained correction coefficient (S3 ′ / S2 ′) is stored in the memory 42MA, and the above-mentioned correction coefficient (S3 ′ / S2 ′) is stored in the GT signal S3 until the GT signal S2 and the S3 calibration command are received next. A multiplied corrected GT signal S3B signal is calculated, and the GT signal S2B is calculated according to a command transmitted from the process computer or the control device via the input / output buffer 46.
And at least one of the corrected GT signal S3B and the GT
Using the sensitivity S ₀ (mv / (W / W / g)) of the sensor,
Equation (33) described above: W = U / {S ₀ (1 + αU)};
However, a signal W expressed by U as at least one of the GT signal S2 and the corrected GT signal S3B is output to the process computer.

That is, normally, during calibration of the GT heater, G
The addition due to the heat input of the in-line heater is added to the T signal and cannot be used as a correct GT signal. However, according to the present embodiment, the GT signal S2 during the heater calibration is delayed by the CPU 42A based on the heater calibration information of the CPU 42A. Since it is not used for the gamma compensation calculation, it is possible to improve the accuracy of the late gamma delay compensation calculation without disturbing the late gamma compensation calculation.

When the sensitivity of the GT sensor is S₀Changed during operation
Gamma delay compensation
As calculation, feeling S₀(MV / (W / g))
Using the signal level S4A of the gamma heating rate (W / g)
When the gamma delay compensation calculation is executed, S₀Is a heater calibration
After being updated, it is delayed by the discontinuous signal level S4A.
This disturbance is applied to the gamma compensation calculation.
In the form, the original (sensitivity S ₀GT signal (before dividing by mV signal)
The gamma delay compensation calculation is performed using
Delay gamma delay compensation without disturbance due to sensitivity change
The accuracy of the calculation can be improved.

Although the GT signal (mV signal) has an error corresponding to the nonlinear coefficient, its value is usually 1 to 2%.
Since this error is not a rounding error, it is more preferable to compensate for the delayed gamma delay at the mV signal stage when the above-mentioned problem is balanced.

Further, the GT signal S3 that has been delayed gamma compensated
May cause a bias with the GT signal S2 that is not delayed gamma compensated. This bias can occur when the initial value input condition is not in an ideal state and when a slight error occurs in the delayed gamma delay compensation calculation. In order to eliminate the discrepancy between the GT signal S2 and the GT signal S3 in that case, the function (7) of the CPU 42A is as follows.
This is important as a countermeasure for bias in actual operation.

[Fourth Embodiment] This embodiment is a modification of the third embodiment. The third embodiment basically differs from the third embodiment in that a delayed gamma compensation operation is performed on the GT signal S2. In contrast, in the present embodiment, the CPU 42A ′ performs a delayed gamma compensation operation on the GT signal S4A that is the result of performing the sensitivity operation, and outputs the result as the GT signal S4B.
It is in the point. Since the signal processing is almost the same as that of the third embodiment, the description is omitted.

In this embodiment, the same effects as those described in the third embodiment can be obtained.

[Fifth Embodiment] FIG. 6 shows an embodiment of an in-furnace instrumentation system using the in-furnace instrumentation signal processing apparatus of the present invention.

FIG. 6 shows a boiling water reactor (B) according to the present invention.
FIG. 1 is a block diagram showing a reactor power distribution monitoring system (WR). In the output distribution monitoring system shown in FIG. 6, the same components as those of the BWR output distribution monitoring system shown in FIGS. 12 to 14 will be described using the same reference numerals.

As shown in FIG. 6, the reactor power distribution monitoring system 129 of the boiling water reactor includes a fixed in-core instrumentation system 130 having a detector and a signal processing device;
A process control computer 120A for monitoring the operating state of the reactor and the core performance is provided.

For example, the process control computer 120A
It is a computer including a PU, a memory, an input console, a display device, and the like, and a part of its processing functions is configured as a reactor power distribution calculating device 131 for calculating a core power distribution. This furnace power distribution calculating device 131
Calculates the reactor power distribution and monitors the core performance.

On the other hand, in the boiling water reactor, a reactor pressure vessel 102 is housed in a reactor containment vessel 101, and a reactor core 103 is housed in the reactor pressure vessel 102.
The reactor core 103 is cooled by a coolant that also serves as a moderator. A large number of fuel assemblies 104 are provided in the core 103.
Are loaded as shown in FIG. 7 and FIG. A large number of fuel assemblies 104 are configured in groups of four each, and a control rod 105 having a cross-shaped cross section is loaded between the four fuel assemblies 104 so as to be able to be taken in and out from below. .

A plurality of in-core instrumentation assemblies 132 constituting a detector of an in-reactor instrumentation system are provided in a core 103 constituted by loading a large number of four fuel assemblies 104 in a set. , For example, are provided. In-furnace instrumentation assembly 13
2 are arranged at positions different from the arrangement positions of the control rods 105, and as shown in FIGS.
It is arranged in a corner water gap G formed between the gaps 04.

That is, the in-furnace instrumentation assembly 132 comprises:
An elongated long tubular in-core instrumentation tube 133, and a neutron detector assembly (LPRM detector assembly) 134 as fixed neutron detection means (LPRM) housed in the in-core instrumentation tube 133 and A γ-ray heat detector assembly (GT aggregate) 135 which is a fixed γ-ray detection means (gamma thermometer).

In the LPRM detector assembly 134, the LPRM detector 137 as a fixed neutron detector is discretely or dispersedly disposed at equal intervals in the core axis direction at several places in the in-core instrumentation tube 133. It is composed. In the boiling water reactor, four LPRM detectors 137 are usually arranged in the active fuel portion of the core 103 at equal intervals in the core axis direction. Further, each LPRM detector 137 penetrates the penetration section 139 by a signal cable 138 and is electrically connected to the LPRM signal processing device 140 to form an output area neutron flux measurement system 141. This LPRM
The signal processing device 140 converts the LPRM signal S _LPRM sent from each LPRM detector 137 into, for example, an A / D signal.
Conversion processing, gain calculation, and other processing are performed to obtain a digital L
The signal is converted into a PRM signal (LPRM data) D2 and transmitted to the process control computer 120A.

On the other hand, the GT assembly 135 includes a plurality of fixed γ-ray heat detectors 21 arranged discretely in the core axis direction. It is designed to measure. The γ-ray heat detector 21 has the same number or more, for example, eight, in the core axis direction as the number of LPRM detectors 137 in the core axis direction, and an aggregate of γ-ray heat detectors is a gamma thermometer assembly ( GT aggregate) 135. γ-ray heat detector (GT
The detectors 21 are arranged at least in the vicinity of the LPRM detector 137, respectively. Each γ-ray heat detector 21 of the GT assembly 135 penetrates the penetration part 149 by the signal cable 145 and is electrically connected to the gamma thermometer signal processing device 148 to configure the gamma thermometer output distribution measuring system 150. You.

Gamma thermometer signal processing device 148
(Hereinafter, it is simply described as a GT signal processing device 148)
Has the same configuration as the GT signal processing device 1 shown in FIG. 1 or the GT signal processing device 1A shown in FIG.
The output signal (GT signal) S1 from each γ-ray heat detector 21 of the T assembly 135 and the sensitivity S of each γ-ray heat detector 21
A digital γ-ray heat measurement signal (GT signal D1; representing a γ-ray heat generation per unit weight (W / g) based on 0)
Hereinafter, this signal is also referred to as GT data D1. This signal corresponds to the above-described signal S4A or S4B).
The T data D1 is transmitted to the process control computer 120A.

That is, the in-furnace in-core instrumentation system 1
Numeral 30 includes the output area neutron measurement system 141 and the gamma thermometer output distribution measurement system 150. The detector group 137, 2
In-core instrumentation assembly (LPRM detector assembly 1
34 and the GT assembly 135) 132 are connected to each detector 13 at a fixed measurement point set in the core 103 in advance.
7 and 21 detection signal transmission and each signal processing device 14
By the signal processing of 0 and 148, the neutron flux and the γ-ray heating value in the core 103 are measured using the in-core instrumentation data (GT data D).
1 and LPRM data D2).

Further, the GT assembly 135 has a built-in heater wire, and has a fixed in-furnace instrumentation system 130.
Is electrically connected to this built-in heater (described later),
A gamma thermometer heater control device for supplying power to the built-in heater and controlling the power supply amount (hereinafter, referred to as a gamma thermometer heater control device)
GT heater control device 153).

The GT heater control device 153 is, for example, a power supply device including a power supply circuit, a current measurement circuit, a voltage measurement circuit, a voltage control circuit (microcomputer), an energization switching circuit, and the like. A voltage is applied to the built-in heater of the GT assembly 135 that has been set, and the heater is heated.

According to the fixed in-core instrumentation system 130 of the nuclear reactor, a mobile neutron detector and a mobile γ-ray detector are not required. The mechanical drive operating device provided can be omitted. Therefore, while the structure of the fixed in-core in-core instrumentation system 130 can be simplified, the in-core
Since no moving parts are required, maintenance-free operation can be achieved, and the work of exposing workers can be eliminated or greatly reduced.

In the reactor pressure vessel 102 or in a primary piping (not shown), various operating parameters for operating the reactor, such as a core coolant flow rate (or an approximate recirculation flow rate) and a core pressure ( Reactor core current process data (process signal) S such as pressure in the pressure vessel, feedwater flow rate, feedwater temperature (or core inlet coolant temperature), and control rod position (control rod pattern) in the control rod drive.
_Reactor core status data measuring device 155 for measuring _PROCESS
Is installed.

In FIG. 6, the core current state data measuring device 155 is simplified and represented by a measuring device inside the containment vessel like a single measuring device. This is a core current data measuring means composed of a plurality of measuring devices for measuring or monitoring core current data (process data).

The core current status data measuring device 155 includes a signal cable 1 that penetrates the penetration portion 156.
57 is connected to the current data processing device 158 via a signal cable 157, and the other components are connected to the current data processing device 158 via a signal cable 157. Is done.

The current status data processing device 158 receives the current core process data S _PROCESS (analog or digital signal) measured by the current core data measurement device 155, and receives the received current core process data S
Data processing is executed based on _PROCESS to calculate reactor heat output, core inlet coolant temperature, etc., and the core current process data S including the calculated reactor heat output
_PROCESS is converted into digital core current state data D3 and transmitted to the process control computer 120A.

The current data processing device 158 of the process data measurement system 159 may be configured as a part of the processing function of the process control computer 120A, instead of a dedicated independent device. In this sense, the process data measurement system 15
Numeral 9 may be configured as a part of the processing function of the process control computer 120A including the in-core power distribution calculating device 131, and the power distribution calculating device of the nuclear reactor is also a part of the processing function. The process data measurement system 159 may be configured as a part of the in-core instrumentation system 130 in the fixed reactor type reactor from the concept of a detector and a signal processing device.

Further, the current data processor 158 of the process data measuring system 159 and the neutron flux measuring system 14 in the output area
1 LPRM signal processing device 140, gamma thermometer heater control device 15 of gamma thermometer heater control system
3 and G of the gamma thermometer output distribution measuring system 150
The T signal processing devices 148 are each electrically connected to the process control computer 120A.

A data group processed by each of the processing units 140, 148, and 158, that is, instrumentation data (GT
The data D1 and LPRM data D2) and the current core data D3 are output from the in-core power distribution calculation device 131 via an in-core instrumentation control device (in-core instrumentation control module) 160 having an interface function of the process control computer 120A.
To be entered.

The in-core instrumentation control device 160, that is, the in-core instrumentation control module 16 of the process control computer 120A
0 is configured as a part of the components of the in-furnace instrumentation system 130. In addition to the above interface functions, the LPRM signal processor 140 and the GT signal processor 148 of the in-furnace instrumentation system 130. And a function of controlling the gamma thermometer heater control device 153, respectively.

The in-furnace power distribution calculator 131 of the process control computer 120A has a built-in physical model (3
Processing function (power distribution calculation module) 161 for calculating the neutron flux distribution, power distribution, and margin for the thermal operation limit value in the reactor core based on the three-dimensional nuclear thermal hydraulic calculation code), and calculation from the power distribution calculation module 161 A processing function (power distribution learning module) 162 for inputting and correcting the result and obtaining a core power distribution reflecting the measured core in-core instrumentation data.
It is composed of In addition, the process control computer 12
0A is an output distribution calculation instruction command via the operator, G
A display capable of inputting various commands such as a T calibration instruction command, and outputting display information such as a warning display in addition to a core performance calculation result (for example, a power distribution and a margin for an operation limit value) to an operator. Display operation device 16 including functions
3 is provided.

The in-furnace power distribution calculating device 131 of the process control computer 120A
Output distribution calculation module 16 stored in (memory of)
1 physical model (BWR 3D simulator model; 3
The core power distribution and the like are calculated based on the three-dimensional nuclear thermal hydraulic power calculation code), the input GT data D1, LPRM data D2, and core current state data D3.

That is, the power distribution calculation module 161 of the in-core power distribution calculation device 131 executes arithmetic processing based on the input core current state data D3 and the physical model (three-dimensional nuclear thermal hydraulic calculation code), The neutron flux distribution, the core power distribution, and the margin for the thermal operation limit value are calculated.

The power distribution learning module 162 of the in-core power distribution calculation device 131 outputs a result (neutron flux distribution and power distribution in the core) calculated by the power distribution calculation module (three-dimensional nuclear thermal hydraulic power calculation module) 161. To the input GT data D1, or GT data D1 and L
The correction is made with reference to the PRM data D2, and the result is returned to the power distribution calculation module 161. The module 161 measures the measured core internal instrumentation data (GT data D1, LPRM data D
A margin for the thermal operation limit value and the like, such as a highly reliable core power distribution reflecting 2) are obtained.

Here, each of the modules 160, 161, 1
Reference numeral 62 denotes a module representing a processing function of the process control computer 120A, that is, a program module built in a memory of the process control computer 120A and a process control computer 120A based on this program module.
(The CPU), and is realized by the in-furnace power distribution calculation module 161 and the power distribution learning module 1
62 together constitute an in-furnace power distribution calculation device 131. The monitoring control module of the in-furnace instrumentation system 130 constitutes the in-furnace instrumentation control device 160.

The in-furnace instrumentation assembly 132 is
As shown in FIGS. 6 to 8, a part of the in-core instrumentation system 130 of the nuclear reactor is configured, and a large number, for example, 52 units are arranged in the reactor core 103. The in-furnace instrumentation assembly 132 includes:
Corner water gap G surrounded by four fuel assemblies 104
Placed in the position.

The in-furnace instrumentation assembly 132 includes an in-furnace instrumentation tube 133, a neutron detector assembly (LPRM detector assembly) 134 as fixed neutron detection means, and a fixed gamma ray detection means ( A gamma thermometer) as an aggregate (GT aggregate) 135 of γ-ray heat detectors,
The LPRM detector assembly 134 and the GT assembly 135 are combined and arranged integrally in a furnace instrumentation tube 133.

The LPRM detector assembly 134 constitutes a local power range monitor system (LPRM) as a fission chamber, and N (N ≧ N) within the active fuel length in the core axis direction.
4) For example, four LPRM detectors 137 are provided discretely or dispersedly at equal intervals (interval L). The GT assembly 135 is inserted into the in-furnace instrumentation tube 133 together with the LPRM detector assembly 134.

The GT assembly 135 has, for example, eight or nine gamma (γ) ray heat generation detectors 21 discretely in the axial direction. Each neutron detector 137 of the LPRM detector assembly 134 and each gamma ray heat detector 21 of the GT assembly 135 are housed in the in-furnace instrumentation tube 133, while the inside of the in-furnace instrumentation tube 133 is cooled. Are guided to flow upward from below.

FIGS. 7 and 8 show an example of a GT assembly 135 in which eight γ-ray heat generation detectors 21 are arranged in a fuel effective portion H in the core axis direction. Note that, as shown in FIG. 8, the fuel effective portion H refers to a region in each fuel element of the fuel assembly (nuclear fuel filled in the fuel pipe) where the nuclear fuel is effectively filled along the core axis direction. The effective fuel portion H along the core axis direction is also referred to as an effective fuel length.

The spacing between the γ-ray heat detectors 21 in the core axis direction is determined in consideration of the spacing between the neutron detectors 137 of the LPRM detector assembly 134 in the core axis direction.

Specifically, assuming that the axial distance between the LPRM detectors 137 is L, the gamma thermometer assembly (GT assembly) 135 is configured such that four of the γ-ray heat detectors 21 are LPRMs. At the same axial position as the detectors 137, three are located at intermediate positions of the respective LPRM detectors 137 at L / 2 intervals,
The lowermost γ-ray heat detector 21 is located at a distance of L / 4 to L / 2 downward from the lowermost neutron detector 137 and within 15 cm or more from the lower end of the active fuel section. It is arranged so that the center comes. LPR at the top
When the γ-ray heat detector 21 is installed above the M detector 137, the γ-ray heat detector 21 has a distance of L / 4 to L / 2 above the uppermost neutron detector 137. And placed within the active fuel section 15 cm or more below the upper end of the active fuel section. Γ from the upper and lower ends of the fuel effective part
The reason why the line heating detector 21 is arranged to be inward by 15 cm or more is that the contribution range of the γ-ray is newly found by the analysis of the γ-ray heating contribution range, and the γ-ray heating value of the upper and lower end portions of the fuel effective portion. Is to be detected with high precision and accuracy.

Since the lowermost γ-ray heat detector 21 is required to be disposed as close to the lower end as possible within the active fuel length H, the active fuel length H (currently about 371 cm) is set, for example, in the core axial direction. If it is divided into 24 nodes, 2 from the bottom
It is preferable to dispose the lowermost γ-ray heat detector 21 so that the center position of the lowermost γ-ray heat detector 21 is located substantially at the axial center of the second core axial node. With this arrangement, the lowermost γ-ray heat detector 21 of the GT assembly 135 can also detect γ-ray heat at the lower end of the core,
The γ-ray heat can be measured from a region as wide as possible in the axial direction of the core along the active fuel length H, and can also be measured in a region on the lower end side of the core.

This is because the output at the lowermost node is originally low due to neutron leakage, the sensitivity of the γ-ray heat detector 21 is low, and the contribution range of the gamma ray to the γ-ray heat detector 21 is 15 cm or more. It is 15 from the lower fuel effective length
By separating the γ-rays from the vertical direction, the γ-ray heat generation detector 21 can equally detect the γ-ray heat generation from the vertical direction. Also, 15c
If not more than m apart, the γ-ray heat detectors 21 at other core axial positions measure the heating effect of γ-rays from above and below in the axial direction, while the lowermost γ-ray heat detector 21 This is to detect only the γ-ray heat generation contribution from, and to lose the balance of the γ-ray calorific value measurement and to avoid a difference in the correlation equation of the output measurement.

In the recent axial design of the fuel assembly 104, the lowermost node often uses a natural uranium blanket. Therefore, even if the low output natural uranium blanket portion is measured, the GT This is because the output signal of the aggregate 135 is extremely low, and there is no point in extrapolating the output distribution below the lowermost LPRM detector 137.

Incidentally, a gamma thermometer assembly (GT assembly) 13 in which a fixed type γ-ray heat generation detector 21 is combined.
Numeral 5 has an elongated bar-like structure shown in FIGS.

Gamma thermometer assembly (GT assembly)
Reference numeral 135 denotes an elongated rod-shaped sensor assembly having a diameter of, for example, about 8 mmφ, and a fuel effective length in a core axis direction, for example, from 3.7 m (370 cm) to 4 m (400 c).
m) has a length substantially covering the extent.

The GT assembly 135 is formed of a cover tube 1 made of, for example, stainless steel as a metal jacket.
65 and a metal long rod-shaped core tube 166 housed in the cover tube 165.
The cover tube 165 is caulked to the core tube 166 and fixed to each other by shrink fitting or cold fitting. Between the cover tube 165 and the core tube 166, there is formed a sleeve-like or annular space portion 167 constituting a heat insulating portion, and a plurality of such annular space portions 167 are provided at intervals in the axial direction, for example, at least four. Specifically, seven to nine discretely are arranged.

The annular space 167 is provided with the core tube 166.
Is formed by notching the outer surface of the ring along the circumferential direction, and a gas having a low thermal conductivity, for example, an Ar gas is sealed in the annular gap 167. The annular gap 167 may be formed on the cover tube 165 side which is a jacket tube. Examples of the gas having low heat conductivity include an inert gas such as an Ar gas and a nitrogen gas.

The position where the annular gap 167 is formed is the position of the fixed γ-ray heat detector (GT detector) 21, and constitutes the sensor section of the gamma thermometer assembly 135.
The core tube 166 has an inner hole 168 that passes through the center in the axial direction, and the cable sensor assembly 170 formed into an MI cable is fixed to the inner hole 168 by brazing or caulking.

The cable sensor assembly 170 has a built-in heater 171 as a rod-shaped heating element which is a heater wire for calibrating the gamma thermometer assembly 135 at the center, and a plurality of differential sensors as temperature sensors around the heater 171. Type thermocouple (thermocouple) 172. The gap between the built-in heater 171 and each thermocouple 172 is fixed by an electric insulating layer or a metal / metal alloy filler 173 if necessary, and housed integrally in the metal cladding tube 174.
74 is in close contact with both the outer and inner surfaces. The built-in heater 171 of the gamma thermometer assembly 135 is formed of, for example, a sheathed heater, and the heater wire 175 is covered with a metal coating tube 177 via an electric insulating layer 176 and is integrated.
Similarly, each thermocouple 172 has a thermocouple wire 178 covered with a metal cladding tube 180 via an electric insulating layer 179 and is integrated.

The differential type thermocouple 172 disposed in the inner hole 168 of the core tube 166 has a low-temperature side contact and a high-temperature side contact.
The γ-ray heat detector 21 which is arranged corresponding to the annular gap 167 and is a sensor of the gamma thermometer assembly 135 is constituted. As shown in FIG. 10, each thermocouple 172 has a high-temperature side contact 181a at the axial center of the sensor portion formed by the annular gap 167, that is, the heat insulating portion, and a low temperature side contact 181b at a position slightly away from the heat insulating portion. (The low-temperature side contact 181b may be at an upper position slightly away from the heat insulating portion). The thermocouples 172 are inserted concentrically around the built-in heater 171 by the number of the γ-ray heat detectors 21.

The fixed type γ-ray heat detector 21 constitutes a gamma thermo-assembly 135 for detecting the power distribution inside the furnace. The principle of measuring the power distribution inside the furnace is shown in FIGS. 11 (A) and 11 (B). Have been.

In a nuclear reactor such as a boiling water reactor, gamma rays are generated in proportion to the amount of nuclear fission of nuclear fuel loaded in the core 103 in the reactor pressure vessel 102, and the generated gamma ray bundle generates a gamma thermometer assembly. The structure 135, for example, the core tube 166 is heated. This heating amount is proportional to the γ-ray flux, and the γ-ray flux is proportional to the amount of fission in the vicinity. In the annular gap 167 of each γ-ray heat detector 21 constituting the gamma thermometer assembly 135, heat removal by the radial coolant 182 is poor due to its heat insulating property, and the axial direction as shown by the arrow A A heat flux that bypasses the airflow is generated, causing a temperature difference. So Figure 1
0, the high-temperature side contact 181 of the differential thermocouple 172
If a and the low-temperature side contact 181b are arranged, this temperature difference can be detected by a voltage signal. Since this temperature difference is proportional to the γ-ray heating value, the γ-ray heating value proportional to the local fission amount can be obtained from the voltage signal of the differential thermocouple 172. This is the measurement principle of a gamma thermometer.

On the other hand, as shown in FIGS. 7 and 8, a large number of fuel rods (not shown) are housed in a rectangular cylindrical channel box 183 in the fuel assembly 104. Each fuel rod has a zirconium alloy fuel cladding filled with uranium oxide sintered pellets or uranium-plutonium mixed oxide sintered pellets, and the upper and lower ends are welded and sealed with end plugs. A large number of fuel rods are collected and bundled, and a plurality of fuel spacers are arranged at intervals in the axial direction in order to secure a predetermined distance between the fuel rods.

Further, an upper tie plate and a lower tie plate are disposed at the upper and lower ends of the fuel assembly 104, respectively.
The lower core structure and the upper core structure are engaged with each other. In the fuel assembly 104 of the boiling water reactor (BWR), the channel box 183 further surrounds the outside of the fuel bundle, and forms a coolant passage for each fuel assembly 104.

[0186] Such a fuel assembly 104 has a large number of cores 1
The calculation of the power distribution inside the reactor and the margins for the core fuel operation limit values (maximum linear power density (kW / m) and minimum limit power ratio) of the reactors established in March 2003 are so-called three-dimensional nuclear thermal hydraulic simulation calculations Process control computer 120
This is performed by the in-furnace power distribution calculation device 131 of FIG. The reactor power distribution calculator 131 calculates a margin or the like with respect to the core fuel operation limit value (maximum linear power density (kW / m) and minimum limit power ratio), and the calculation result is displayed by the display operation device 163. The operator is informed.

Next, the reactor power distribution monitoring process and the reactor power distribution monitoring method of the reactor power distribution monitoring system 129 of the present embodiment, in particular, the detection sensitivity calibration process of the fixed in-core in-core instrumentation system 130 And GT detector 21
The detection sensitivity calibration method will be mainly described.

According to the reactor power distribution monitoring system 129 of this embodiment, the core 10 of the boiling water reactor (BWR) is used.
The fuel status and the reactor operation status of No. 3 are monitored by the process control computer 120A.

That is, various process data (control rod pattern, core coolant flow rate, reactor dome pressure, feed water flow rate, feed water temperature) as the reactor current data measured by the reactor core current data measuring device 155 of the boiling water reactor , (Core inlet coolant temperature), etc., are input to the current state data processing device 158 and subjected to data collection processing by the core state current data measuring device 155 to calculate the reactor heat output and the like.

The current data processing device 158 may be configured as a part of the process control computer 120A. In this case, the data collection processing of the core current data is performed by the process control computer 120A.

The core current data D3 including the reactor heat output, which has been subjected to the data collection processing and the calculation processing by the current data processing device 158, is transmitted via the signal interface function of the in-core instrumentation control device 160 of the process control computer 120A. Is transferred to the in-furnace power distribution calculation device 131.

On the other hand, the LP of each in-furnace instrumentation assembly 132
The neutron flux in the core 103 detected by the RM detector assembly 134 passes through the LPRM signal processor 140
It is converted into PRM data D2, and the process control computer 12
It is transferred to the in-furnace power distribution calculating device 131 via the signal interface function of the in-furnace instrumentation control device 160 of 0A.

Similarly, γ of each in-furnace instrumentation assembly 132
Thermocouple output signal (G
Based on the sensitivity S0 of the γ-ray heat detector 21, the GT signal processor 148 determines the amount of γ-ray heat generated per unit weight (W / T signal) based on the sensitivity S0 of the γ-ray heat detector 21. g), which is converted into GT data D1 (S4A signal and / or S4B signal of the previous embodiment, or both), and the power distribution in the furnace through the signal interface function of the in-core instrumentation control device 160 of the process control computer 120A. It is transferred to the calculation device 131.

The in-core power distribution calculating device 131 performs arithmetic processing based on the transferred GT data D1, LPRM data D2, core current data D3, and three-dimensional nuclear thermal hydraulic calculation code built in the process control computer 120A. Then, the core power distribution, the core neutron flux distribution, the margin for the thermal operation limit value, and the like are calculated. Then, the calculated data such as the core neutron flux distribution, the core power distribution, the calculated value of the GT signal reading, and the margin for the thermal operation limit value are stored in the memory as needed.

That is, the output distribution calculation module 161
From the core current data D3 and the three-dimensional nuclear thermal hydraulic calculation code, the core neutron flux distribution, core power distribution, G
The calculated value of the T signal reading (corresponding to the actually measured GT data D1), the margin for the operation limit value, and the like are calculated.

In the simulation calculation of the GT signal reading, the memory of the process control computer 120A stores the parameter の of the correlation equation for expressing the correlation between the fuel assembly node output value and the GT data value D1 based on the GT signal. For example, fuel type, nodal burnup, control rod presence,
Fitting equation data (data set) based on the historical relative water density (history void rate), instantaneous relative water density (instantaneous void rate)｝, or lookup table data based on the interpolation equation based on the above correlation equation parameters (data set) Data set) is stored, and the GT reading value is calculated using the above parameter values calculated by the output distribution calculation module 161.

The calculated core power distribution and the like are learned and corrected based on the core in-core instrumentation data (GT data D1) actually measured from the core 103 and the three-dimensional nuclear thermal hydraulic calculation code.

At this time, the GT assembly 135 is
3 has less than 24 nodes and the same number of fixed GT detectors 21 as the fixed LPRM detector 137, for example, four or more than four, and each GT Calculated by the output distribution calculation module 161 based on the in-core instrumentation data (GT data D1) corresponding to the GT signal measured by each GT detector 21 of the assembly 135 and the three-dimensional nuclear thermal hydraulic calculation code. The obtained core power distribution and the like are learned and corrected.

That is, the actual thermocouple output signal (GT signal) S1 from the GT assembly 135 is converted by the GT signal processor 148 from the voltage signal into GT data D1 (delayed) corresponding to the gamma ray heating value (W / g). Gamma compensated signal S4B
Or S4 in a well-balanced state without delayed gamma compensation
The result is converted to A) and input to the output distribution calculation device 131 of the process control computer 120A.

At this time, the power distribution learning module 162 of the power distribution calculation device 131 calculates the axis of each GT assembly from the reactor power distribution calculated based on the three-dimensional nuclear thermal hydraulic calculation model of the power distribution calculation module 161. The γ-ray calorific value for each direction node is obtained by simulation calculation and temporarily stored in a memory. The stored simulated γ-ray calorific value for each node and the actual measurement value (the value of the GT data D1) ) Is obtained in the form of a ratio for the node where the GT detector actually exists.

In the power distribution learning module 162, the measured value of the actual γ-ray calorific value (the value of the GT data D1) whose number is limited in the core axis direction is provided for each GT assembly 135.
(Γ-ray calorific value difference correction amount data) representing the difference (ratio form) between the calculated value and the simulation calculation value of the γ-ray calorific value is extrapolated to each node in the core axis direction, and γ-ray heat generation for all axial nodes The amount difference correction amount data is obtained. In addition,
In addition to the extrapolation in the axial direction, it is also possible to extrapolate the γ-ray calorific value difference correction amount (correction ratio; correction coefficient) along the core radial direction to the radial position where the GT aggregate does not exist. is there.

The output distribution learning module 162 determines that the value of the γ-ray heat generation difference correction amount data for each node of each GT aggregate thus obtained is “1.0”,
The accuracy of the reactor power distribution calculated by the power distribution calculation module 161 is corrected so that the value of the GT data D1 at each node in the axial direction of the T-assembly coincides with the simulation calculation value of the γ-ray heating value. The reactor power distribution (or the neutron flux distribution) with a high value and the margin for the operation limit value are determined.

As described above, the process control computer 120 monitors the operating state of the reactor and monitors the power distribution of the core.
A receives the core status data D3 constantly and continuously, and updates the latest operating parameters at regular intervals (for example, once an hour) or at any time in response to a calculation request command input by an operator's input / output device operation. The core power distribution calculation (three-dimensional nuclear thermal hydraulic simulation calculation) is performed by the in-core power distribution calculator 131 based on the (core current state data D3) and the three-dimensional nuclear thermal hydraulic code.

That is, the output distribution calculation module 161
Is corrected by the power distribution learning module 162 based on the GT data D1 (W / g) in which the effect of the delayed gamma based on the GT signal S1 at that time does not exist or is removed. By doing so, it is possible to provide a highly accurate reactor power distribution and operating limit values,
(And also the neutron flux distribution) can be calculated.

Further, in the fifth embodiment, even when the GT signal detected by the GT detector does not reach the signal level of the equilibrium state of the gamma decay chain due to the delayed gamma component, the delay occurs. By compensating for the gamma component, the response of the GT detector 44 can be easily corrected to 3
A dimensional output distribution learning process can be performed. Therefore, the GT in the simple fixed in-core in-core instrumentation system 30
Using only the detector signal, the minimum critical power ratio (MCP
Monitoring of thermal limits during operation, such as R), maximum linear power density (MLHGR), can be performed at any point within a practical delay.

[0206]

As described above, according to the in-core instrumentation signal processing apparatus and the in-core instrumentation system of the nuclear reactor of the present invention, even if the GT signal is in an unbalanced transient state, the LPRM can be used.
Can be calibrated and the LPRM signal can be used to perform core power distribution calculations and thermal operating limit parameter calculations on a scheduled or ad hoc basis.

Further, according to the in-core instrumentation system of the nuclear reactor according to the present invention, even if the GT signal is in a non-equilibrium transient state, the delayed gamma component is compensated to compensate for the instantaneous gamma ray heating. A GT signal is calculated, and the calculated compensation G is calculated.
The T signal can be used to perform LPRM gain adjustment or core power distribution calculations and thermal operating limit parameter calculations on a regular or ad hoc basis.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a reactor instrumentation signal processing device and a GT heater control device of a nuclear reactor according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a delayed gamma compensation module in the in-core instrumentation signal processing device according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a functional configuration of a GT control panel in the in-core instrumentation signal processing device according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a hardware circuit configuration of a delayed gamma compensation module in a furnace instrumentation signal processing device according to a second embodiment of the present invention.

FIG. 5 is a block diagram showing a schematic configuration of an in-core instrumentation signal processing device and a GT heater control device of a nuclear reactor according to a third embodiment of the present invention.

FIG. 6 is a block diagram showing a schematic configuration of an in-core instrumentation system of a nuclear reactor according to a fifth embodiment of the present invention.

FIG. 7 is a partially cutaway perspective view showing a detector arrangement relationship of a GT power distribution measuring system in a reactor internal instrumentation system according to a fifth embodiment of the present invention.

FIG. 8 is a partially cutaway perspective view showing a detector arrangement relationship of the GT output distribution measuring system in FIG. 7;

FIG. 9 is a perspective view showing an example of the structure of a gamma thermometer assembly with a partial cutout.

FIG. 10 is a diagram illustrating a principle of measuring a γ-ray heating value of a gamma thermometer detector.

11A is a view for explaining the principle of measuring gamma heat generation of a gamma thermometer detector, and FIG. 11B is a view showing a flow of heat by partially setting each of FIGS.

FIG. 12 is a block diagram of a conventional reactor power distribution monitoring device, a power distribution calculating device, and a reactor power distribution monitoring system.

FIG. 13 is a diagram showing a detector arrangement relationship of a conventional power distribution measuring device, showing a movable neutron detector and a fixed neutron detector.

FIG. 14 is a diagram showing a detector arrangement relationship of a conventional power distribution measuring device, and showing a combination of a mobile γ-ray detector and a fixed neutron detector.

[Explanation of symbols]

1, 1A, 148 Furnace instrumentation signal processing device (GT signal processing device) 2, 153 GT heater control device (GT heater control panel) 3, 3A GT signal site panel 4, 4A GT control panel 21 GT sensor 22 Amplifier 23 Filter 24 Multiplexer 25 Analog / Digital Converter 26 GT Signal Amplification Module 30 Signal Processor 31 M, 42 M, 42 MA Memory 32 Signal Holding Circuit 33 Late Gamma Compensation Module 35, 46 Input / Output Buffer 37 Input / Output 42, 42 A CPU 44, 44 A , 52 transmitter 45 display / input / output console 53 optical cable 61 differential amplifier circuit 62 filter circuit 62A, 63A, 64A, 65A, 66A operational amplifier 63 addition circuit 64 primary delay circuit 65 integration circuit 66 inversion circuit 101 reactor containment vessel 02 Reactor pressure vessel 103 Reactor core 104 Fuel assembly 105 Control rod 120, 120A Process control computer 130 Fixed in-core in-core instrumentation system 131 In-core power distribution calculation device 132 In-core instrumentation assembly 133 In-core instrumentation tube 134 Neutron detector assembly (fixed neutron detection means,
LPRM detector assembly 135 Gamma ray heat detector assembly (fixed γ-ray heat detector, GT assembly, gamma thermometer assembly) 137 Fixed neutron detector (LPRM detector) 138, 157 Signal cable 139 149, 156 Penetration unit 140 LPRM signal processing device 141 Output region neutron flux measurement system (output region neutron flux measurement device) 145 Signal cable 150 Gamma thermometer output distribution measurement system (gamma thermometer output distribution measurement device) 153 Gamma thermometer Heater control device 154 Power cable 155 Current core data measurement device 158 Current data processing device 159 Process data measurement system 160 In-core instrumentation control device (In-core in-core instrumentation system monitoring and control module) 161 Output distribution calculation module (3-dimensional core) Thermo-hydraulic calculation module 162 Output distribution learning module 163 Display operation device (display device) 165 Cover tube 166 Core tube 167 Void 168 Inner hole 170 Cable sensor assembly (MI cable) 171 Built-in heater (heater wire) 172 Differential thermocouple 173 Filler 174 Metal cladding tube 175 Heater wire 176 Electric insulating layer 177 Metal cladding tube 178 Thermocouple element wire 179 Electric insulating layer 180 Metal cladding tube R ₆₂ , R _{63a1 to} R _63a10 , R _63af, R
_{64a1 ~R 64a10, R 65a1 ~R 65a10} ,
_{R 66a1} ~R 66a10 resistance _{C 62, C 64a1 ~C 64a10,} C 65a1 ~C
_65a10 capacitor

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasushi Goto 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture F-term in Toshiba Yokohama Office 2G075 AA03 BA03 CA08 CA38 DA01 FA19 FB04 FB05 GA15

Claims (12)

[Claims] 1. An in-core instrumentation signal processing device for processing a γ-ray heating value (gamma thermometer signal) detected as a local power distribution in a power region in a reactor, wherein the detected gamma thermometer signal is The included late gamma component is represented by its time constant and weight, and the delayed gamma component represented by the time constant and weight is removed from the gamma thermometer signal to obtain a gamma thermometer signal free from the influence of the delayed gamma component. An in-furnace instrumentation signal processing device comprising a means for determining. 2. An in-core instrumentation signal processing device for processing a γ-ray heating value (gamma thermometer signal) detected as a local power distribution in a power region in a nuclear reactor, wherein the detected gamma thermometer signal is Assuming that R (t), the gamma thermometer signal R (t) has an instantaneous response component term P (t) and an exponential attenuation weight having a plurality of time constants τ _m and each time constant τ _m. And a sum obtained by integrating the product of the instantaneous response terms from the past to the present, using the following equation: Where: And a means for compensating a delayed gamma delay of the gamma thermometer signal based on the equation (1). 3. An in-core instrumentation signal processing device for processing a γ-ray heating value (gamma thermometer signal) detected as a local power distribution in a power region in a reactor, wherein the detected gamma thermometer signal is When R (t), the gamma thermometer signal R (t) is converted into an instantaneous response component term P (t) including a delayed gamma component up to a thermal time constant of the gamma thermometer, and the gamma thermometer. A plurality of time constants τ _m longer than the thermal time constant of the meter, and the sum of the product of the exponential damping weight and the instantaneous response term of each time constant τ _m integrated from the past to the present. Using the following equation However, And a means for compensating for a delayed gamma delay of the gamma thermometer signal based on the equation (3). The delayed gamma delay compensating means is provided from the thermal time constant of the gamma thermometer to the day. A means for performing the delayed gamma component compensation calculation by using the time constant of (1). 4. An in-core instrumentation signal processing device for processing a γ-ray heating value (gamma thermometer signal) detected as a local power distribution in a power region in a nuclear reactor, wherein the detected gamma thermometer signal is R (t), the gamma thermometer signal R (t) is converted into an instantaneous response component term P (t) including a delayed component up to a thermal time constant of the gamma thermometer, and the gamma thermometer Having a plurality of time constants τ _m having a long time constant equal to or longer than the thermal time constant of, and a sum of products of the exponential damping weight and the instantaneous response term of each time constant τ _m integrated from the past to the present time. Expression 5 Where: And a means for compensating for a delayed gamma delay of the gamma thermometer signal based on the equation (6), wherein the delayed gamma delay compensating means is provided from the thermal time constant of the gamma thermometer to the day. 1 or more days as an additional pseudo-term representing the time constant of
An in-furnace instrumentation signal processing device characterized in that the delayed gamma delay compensation calculation is performed by adding an exponential attenuation weight based on a predetermined one time constant within a week or less. 5. The delayed gamma delay compensating means includes means for removing noise from a gamma thermometer signal (differential thermocouple signal (mV)) from the gamma thermometer by filtering, and the gamma from which the noise has been removed. The delayed gamma delay compensation calculation is performed based on a thermometer signal, while the gamma thermometer signal is detected by a gamma thermometer assembly having a thermocouple type gamma ray heat detector. The gamma thermometer signal U _c compensated by the late gamma delay compensation operation of the late gamma delay compensation means,
Sensitivity S ₀ (mv / (W / W / g)) of the gamma ray heat detector and gamma ray calorific value W _c (W / g) of the gamma ray heat detector
W _c = U _c / {S ₀ (1 + αU _c )} (7) where α is a nonlinear coefficient of the thermocouple of the γ-ray heat detector, and the arithmetic processing is performed based on the following equation. Heat value _Wc (W /
The in-furnace instrumentation signal processing apparatus according to any one of claims 2 to 4, further comprising means for determining g). 6. The gamma thermometer assembly according to claim 1, wherein
A heater wire for sensitivity calibration of the line heating value detector is built in, and during the sensitivity calibration by the built-in heater wire, that is, until a predetermined delay time elapses after receiving the heater calibration command, the delay is set. The gamma emission delay compensating means performs a delayed gamma delay compensation operation on the assumption that the output signal (mV signal) of the γ-ray heating value detector immediately before receiving the heater calibration command is maintained at a constant value. 6. The in-furnace instrumentation signal processing apparatus according to claim 5, wherein the processing is performed. 7. The delayed gamma delay compensating means uses the following equation (8): Said gamma thermometer signal R (t) and each -a m _· u m _(t) of the adder and a ₀ by the addition circuit for obtaining the instantaneous response component term P (t) by performing division on the basis of, the added The output P (t) of the circuit is multiplied by a different time constant τ _m to perform integration and the following equation (9) is obtained. Respectively output a plurality of integrator circuits for outputting u _{m (t)} of each of said plurality of output from the integrating circuit a plurality of output signals u _{m (t)} of each inverted -u m _{(t) is} shown in a plurality of inversion circuits and the plurality of each multiplied by a coefficient _{a m} of the formula (8) in respect output from the inverting circuit output signal _{-u m (t) -a m ·} u m (t) the a plurality of coefficient multiplier circuit for obtaining respectively, the said plurality of coefficient multiplying circuits respectively output _{-a m · u m (t)} γ
7. The in-furnace instrumentation according to claim 6, wherein the delayed gamma delay compensation calculation is performed by inputting the measured value R (t) of the linear heat detector to the addition circuit. Signal processing device. 8. The delay gamma delay compensating means includes:
Gamma sensors detected by a number of gamma ray heat detectors
Multiple amplifiers that input and amplify each of the meter signals
From the output signals of the plurality of amplifiers,
Multiple low-pass filter hands to remove each signal component
And a constant frequency by the plurality of low-pass filter means.
Multiple signals from which more than a few signal components have been removed
Signal selecting means for sequentially selecting, and the signal selecting means
An analog converter that converts the selected signal to a digital signal
Digital conversion means and this analog / digital conversion
Means for outputting the plurality of γ-rays
Corresponding to R (t) for each heat detector
Gamma thermometer value R_{i, n}(However, i is each γ-ray heat
Values corresponding to detectors, n is data for each γ-ray heat detector
Γ-ray heat detectors compare heaters
If the normal processing is not being executed, the latest gamma
Update and store the meter value and execute the heater calibration process
The gamma thermometer value update process
The first data storage means, and the P (t) and
u_{i, m}P corresponding to (t)_{i, n}(T) and
Bi _{i, m, n}(However, i corresponds to each γ-ray heat detector.
N is the number of times the delayed gamma delay compensation calculation has been executed)
Store at least the results of the last two operations
Second data storage means,_m(M = 0-M)
And τ_mThird data storage means for storing (m = 1 to M)
And a step stored in the first data storage means.
R_{i, n}, P stored in the second data storage means.
_{i, n-1}, P_{i, n-2}, U_{i, n-1}, U
_{i, n-2}And stored in the third data storage means.
A_m, Τ_mData for each γ-ray heat detector
Constant calculation period Δ while synchronizing with sampling timing
At t, the operations of the following equations (10) and (11) are executed, and
A value P corresponding to P (t) for each linear heat detector
_{i, n}(However, i is a value corresponding to each γ-ray heat detector, n
Is the number of executions of the delayed gamma delay compensation calculation)
The late gamma delay compensation operation is performed by digital operation.
7. An in-furnace meter according to claim 6, further comprising:
Signal processing equipment. (Equation 10)[Equation 11]However, the initial condition 9. An in-core instrumentation signal processing apparatus for processing a thermocouple signal S1 corresponding to a local power distribution in an output region in a reactor detected by a detecting means having a thermocouple for detecting a γ-ray heating value. An amplification module that amplifies and filters the thermocouple signal S1 detected by the detection means and outputs the amplified signal as a first gamma thermometer signal S2, and the first gamma thermometer signal S2,
Equations (12) and (13) below [Equation 14] , A delayed gamma delay compensation operation for obtaining a second gamma thermometer signal S3 represented by P in the above equations (12) and (13) is performed, and the second gamma thermometer signal S3 is output. A delay compensation module
The first and second gamma thermometer signals S2
And S3 to execute the sensitivity calculation of the γ-ray heater, and convert the signal into a first gamma heat signal W _u without delay compensation and a second gamma heat signal W _c with delay compensation.
An in-furnace instrumentation signal processing device comprising a signal control module. 10. The GT signal control module according to a command from a process computer or a control device for controlling the in-core instrumentation signal processing device, the first and second gamma thermometer signals S2 and S2. Upon receiving the calibration command of S3, the first and second gamma thermometer signals S2 and S3 are respectively subjected to an average value or a moving average value calculation for a predetermined period of time to execute the first average gamma thermometer. Means for producing a signal S2 'and a second average gamma thermometer' signal S3 ';
, A correction coefficient (S3 ′ / S2 ′) is determined so as to match the average gamma thermometer signal S2 ′, and the determined correction coefficient is stored to store the next first and second gamma thermometer signals S2 ′.
The second gamma thermometer signal S3 is multiplied by the correction coefficient until the second gamma thermometer signal S3 is received.
Means for calculating the corrected gamma thermometer signal S3B, and the first gamma thermometer signal S2 and the second corrected gamma thermometer for the process computer in response to a command from the process computer or the control device. Using at least one of the signals S3B and the sensitivity S ₀ (mv / (W / W / g)) of the γ-ray heat detector,
W = U / {S ₀ (1 + αU)} (14) where at least one of the first gamma thermometer signal S2 and the second correction gamma thermometer signal S3 10. An in-furnace instrumentation signal processing apparatus according to claim 9, further comprising means for outputting a signal W represented by: 11. An in-core instrumentation signal processing apparatus for processing a thermocouple signal S1 corresponding to a local power distribution in an output region in a reactor detected by a detecting means having a thermocouple for detecting a γ-ray heating value. An amplification module that amplifies and filters the thermocouple signal S1 detected by the detection means and outputs the amplified signal as a first gamma thermometer signal S2; and an amplifier module for the first gamma thermometer signal S2 and the γ-ray heat detector. Using the sensitivity S ₀ (mv / (W / W / g)), the following equation is obtained: W = U / {S ₀ (1 + αU)} (15) where the first gamma thermometer signal S2 Is U,
The first gamma heat signal W _u without delayed gamma delay compensation represented by the following formula is obtained, and noise cut processing of the obtained first gamma heat signal W _u is performed, and the noise-cut first gamma heat signal is obtained. W _u, and the following equations (16) and (17) (Equation 18) The delay gamma delay compensation calculation is performed based on
6) and (17) and a GT signal control module to obtain the second gamma heating signal W _c that is lag compensation represented by P in, the GT signal control module, process computer or the furnace instrumentation signals when the command from the control unit for controlling the processing apparatus has received h the first and second gamma heating signal W _u and W _c calibration command, the first and second gamma heating signal W _u and W
means for executing a respective average value or moving average value calculation for a predetermined time in _{c to} generate a first average gamma heat signal W _u ′ and a second average gamma heat signal W _c ′;
A correction coefficient (W _c ′ / W _u ′) is _calculated so as to match the first average gamma heat signal W _u ′, and the obtained correction coefficient is stored to store the next first and second gamma heat signals W _u ′. until it receives a calibration command _u and W _c, and means for calculating a second correction gamma heating signal W _{c B} multiplied by the correction coefficient to the second gamma heating signal W _c, from the process computer or control unit Means for outputting at least one of the first gamma heat signal W _u and the second correction gamma heat signal W _c B to the process computer in response to the command In-furnace instrumentation signal processor. 12. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor.
And a fixed γ-ray heat detector of a gamma thermometer assembly for detecting γ-ray heating value are housed in a furnace instrumentation tube, and the γ
An in-core instrumentation assembly in which a linear heat detector is disposed at least in the vicinity of the LPRM detector, LPRM signal processing means for processing a neutron flux detection signal from the LPRM detector, and the gamma thermometer assembly A gamma thermometer signal is processed by the in-furnace instrumentation signal processing device according to any one of claims 1 to 11, and energization control to a heater built in the gamma thermometer assembly. Gamma thermometer heater control means for performing, the gamma thermometer heater control means controls the amount of current applied to the built-in heater of the gamma thermometer assembly, and each of the gamma thermometer assembly by heating the heater An in-core instrumentation system for a nuclear reactor, comprising means for calibrating an output voltage sensitivity of a detector.