JPH06273563A - Protecting equipment of reactor - Google Patents

Abstract

PURPOSE:To reduce a burden on an operator in charge of calibration of local area neutron flux signal detectors by lessening the number of the detectors by adding functions of stopping withdrawal of fuel rods and preventing an increase in distortion of an output distribution to protecting equipment. CONSTITUTION:A core 1 is divided into a plurality of local areas. Signals from allotted neutron flux detectors 3 are averaged 4, a local neutron flux signal (ai) is delivered, a maximum value is received 5 and a maximum neutron flux signal MAXai is outputted. Meanwhile, signals from all of the detectors 3 in the core 1 are averaged 6 and a core average neutron flux signal (b) is outputted. A function generator 7 sets a set value (f) (MAXai/b), a value f/b is determined by a comparator 8 and an output rise control signal is delivered therefrom when this value exceeds 1. On the other hand, control rods 2 belonging to the same control area are grouped, positional deviations of the control rods 2 in the group are detected 9, tolerance determination 10 is executed and a withdrawal stop signal is delivered. Since a local monitoring range extends over the whole control area, according to this constitution, the number of the averaging circuits 4 can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactor protection device,
In particular, the present invention relates to a reactor protection device that suppresses a decrease in thermal tolerance during a transient event with a distorted power distribution.

[0002]

2. Description of the Related Art An example of prior art relating to a reactor protection device will be described with reference to FIGS.

FIG. 2 shows an example of the arrangement of control rods in the nuclear reactor, and FIG. 3 shows the local area obtained by dividing the inside of the nuclear reactor.
Further, FIG. 4 shows an example of the sequence of pulling out the control rods in the reactor core at the time of starting the reactor.

As shown in FIG. 2, a large number of control rods 2 are present in the reactor core 1, and a transient event in which any one control rod 2 is continuously pulled out due to an erroneous operation of an operator or the like. Occurs, the output distribution near the pulled-out control rod 2 is greatly distorted.

In order to make the monitoring method of the signal showing the neutron flux value for each local region, that is, the local region neutron flux signal effective against the occurrence of such a transient event, it is shown in FIG. As described above, it is necessary to divide the inside of the reactor core 1 into a large number of local regions.

For example, in the case of FIG. 3, the number of local regions is three.
In the case of quadrupling each local area neutron flux signal, the total number of local area neutron flux signals reaches 148 from the viewpoint of further improving reliability.

Further, during normal reactor startup, the control rods 2 are pulled out in accordance with the pulling-out order as shown in FIG. 4, and a plurality of control rods 2 shown in FIG. The control rod is spirally pulled out with its axial positions almost aligned. As long as this control rod drawing method is followed, the strain amount of the power distribution in the reactor core is maintained within the allowable range.

That is, as shown in FIG. 4, a plurality of control rods belonging to the same drawing order are grouped, and a deviation which is a difference between the maximum value and the minimum value of the axial positions of the control rods belonging to the same group is monitored. When the positional deviation exceeds the allowable value, the control rod withdrawal stop signal is transmitted to maintain the distortion amount of the power distribution in the core within the allowable range.

Japanese Patent Laid-Open No. 1-305397 discloses a circuit in which a plurality of neutron flux detectors are installed in a nuclear reactor core and a neutron flux signal detected by each of these neutron flux detectors is processed. Setting to divide the inside of the core into a plurality of local regions and to transmit the output increase suppression signal as a function of the ratio between the maximum value of the neutron flux signals in each local region and the average value of the neutron flux signals in the core A related technique is disclosed in which the value is changed to suppress a decrease in thermal tolerance during a transient event in which the output distribution is distorted.

[0010]

In the prior art, when monitoring the strain of the local power distribution observed when the control rod is pulled out, the core is divided into a large number of local regions as described above, and each local region is divided. It was necessary to provide local region neutron flux signal detectors that were multiplexed for each.

That is, in the event of a transient event in which one of the control rods is continuously pulled out due to a malfunction of the control rod control device or the like, in order to suppress the decrease in the thermal tolerance, it is necessary to use the multiplexed local regions. It was necessary to accurately monitor the local region neutron flux signal near the control rod with the neutron flux signal detector.

Therefore, it takes a lot of time to calibrate the local area neutron flux signal detector, which imposes a great burden on the operator in charge of the calibration.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a reactor protection device capable of the following. That is, (1) Reducing the burden on the calibration of the local region neutron flux signal detector.

(2) Accurate monitoring of the amount of distortion of the output distribution after normal operation.

(3) Improving the reliability of the output rise suppression signal.

(4) Improving the reliability of the control rod withdrawal stop signal.

(5) Detailed monitoring of the thermal margin of the reactor.

(6) Appropriate suppression of thermal tolerance reduction during transient events in which the output distribution is distorted.

(7) Accurate monitoring of the amount of distortion of the output distribution when some neutron flux detectors cannot be used.

(8) Preventing unnecessarily reduced driving margin.

[0021]

The above object can be achieved as follows.

(1) Pulling out the control rod by determining whether or not the allowable value of the axial position deviation between the control rod position detector for detecting the axial position of the control rod in the reactor core and the control rod is exceeded. It has a control rod position deviation non-permissible deciding device that sends a stop signal, and the axial position deviation between the control rods inside each of the multiple groups of control rods obtained by dividing the inside of the core has an allowable value. Control rod withdrawal stopping means for stopping the withdrawal of control rods when exceeding, and a plurality of neutron flux detectors for detecting neutron flux in the core, and each of a plurality of regions obtained by partitioning the core, neutrons An averaging circuit (A) for averaging the neutron flux detected by the flux detector,
Averaging circuit for averaging the total neutron flux in the core
(B), a maximum value detection circuit that detects the maximum value of the neutron flux signal (A) when the averaged value of the neutron flux in each averaging circuit (A) is used as a signal, and a neutron flux The maximum value of the signals (A) and the neutron flux signal (B) when the averaged value of the entire neutron flux in the core in the averaging circuit (B) is used as a signal, and the neutron flux signal is received. (A)
A function generator that sets a set value as a function of the ratio of the maximum value of the neutron flux signal (B) and transmits the set value, and the set value and the value of the neutron flux signal (B). In comparison, a comparator for transmitting an output increase suppression signal in the core when the value of the neutron flux signal (B) exceeds the set value is provided, and an output increase suppression means for suppressing the output increase in the core is additionally provided. To be.

(2) In (1), the neutron flux signal (A)
A circuit is provided to calibrate the neutron flux signal (B).

(3) In (1), the function generator has
In addition to the maximum value of the neutron flux signal (A) and the neutron flux signal (B), means for inputting the core flow rate or core pressure as a signal shall be provided.

(4) In (1), among the signals from the plurality of neutron flux detectors input to the averaging circuit (A), up to the number of signals that are permitted by a predetermined combination are input. It shall be allowed to be excluded, and means for averaging only the signals from the remaining neutron flux detectors not excluded to obtain a neutron flux signal (A) shall be provided.

(5) In (1), a means for excluding the output increase suppressing means is provided except when the control rod is used in a predetermined manner.

(6) Pulling out the control rod by determining that the control rod position detector for detecting the axial position of the control rod in the core of the nuclear reactor and the allowable value of the axial position deviation between the control rod are exceeded. It has a control rod position deviation non-permissible deciding device that sends a stop signal, and the axial position deviation between the control rods inside each of the multiple groups of control rods obtained by dividing the inside of the core has an allowable value. Control rod withdrawal stopping means for stopping the withdrawal of control rods when exceeding, a plurality of temperature detectors for detecting the coolant temperature in the core, and a temperature in each of a plurality of regions obtained by dividing the core An averaging circuit (a) for averaging the coolant temperature detected by the detector and an averaging circuit for averaging the entire coolant temperature in the core
(b) and the coolant temperature signal when the average value of the coolant temperature in each averaging circuit (a) is used as a signal
The maximum value detection circuit for detecting the maximum value of (a), the maximum value of the coolant temperature signal (a) and the averaging circuit (b) averaged all the coolant temperatures in the core. A set value as a function of the ratio between the maximum value of the coolant temperature signal (a) and the value of the coolant temperature signal (b) when the coolant temperature signal (b) when the value is a signal is received. Is compared with the function generator that transmits the set value and the value of the coolant temperature signal (b) is compared, and when the value of the coolant temperature signal (b) exceeds the set value, It has a comparator for transmitting an output increase suppression signal, and is provided with an output increase suppressing means for suppressing an output increase in the core.

(7) In (6), the coolant temperature signal
A circuit is provided to calibrate (a) to the coolant temperature signal (b).

(8) In (6), the function generator has
Maximum value of coolant temperature signal (a) and coolant temperature signal (b)
In addition to the above, it shall be equipped with means for inputting core flow rate or core pressure as a signal.

(9) In (6), from the signals from the plurality of temperature detectors input to the averaging circuit (a), the input signals are excluded up to the number permitted by the predetermined combination. The temperature of the coolant, averaging only the signals from the remaining temperature sensors that are not excluded.
Must have the means (a).

In (10) and (6), a means for excluding the output increase suppressing means is provided except when the control rod is used in a predetermined manner.

(11) In (1) or (6), a plurality of circuits for transmitting a control rod withdrawal stop signal through a 1out of 2 logic circuit are provided independently.

(12) In (1) or (6), the output increase suppression signal is set to 1 out of2 twice, 2 o.
A plurality of circuits that independently transmit via a logic circuit of ut of 4 or 2 out of 3 are independently provided.

[0034]

In the present invention, during normal operation, a plurality of control rods that are driven in a state where the axial positions are aligned are grouped, and when the axial deviation between the control rods in the same group becomes large, the control rods are Since the function to stop the pulling out and suppress the increase in the distortion of the output distribution is added, it becomes possible to exclude the monitoring of the local region neutron flux signal, or to expand the monitoring range of one local region. The number of neutron flux signal detectors can be significantly reduced.

Further, when the reactor power control is affected by the limitation of the drive amount of the control rod, the function of suppressing the power increase of the reactor is used without limiting the drive amount of the control rod. The protection can be performed without affecting the nuclear power output control.

At the time of an abnormal control rod withdrawal event, the maximum value of each local region neutron flux signal increases more than the increase of the core average neutron flux signal, and the maximum value of each local region neutron flux signal is The ratio to the core mean neutron flux signal increases with increasing strain in the power distribution. However, in this case, in accordance with the increase in the ratio of the maximum value of each local region neutron flux signal and the core average neutron flux signal, the set value for transmitting the output increase suppression signal, because it is reduced by the function generator. , It is possible to suppress a decrease in the thermal tolerance during a transient event in which the output distribution is distorted.

In addition, since the value of each local region neutron flux signal can be calibrated to the value of the average neutron flux signal during normal operation, the output distribution of the output distribution can be maintained without being affected by the output distribution during normal operation. The amount of increase in strain can be accurately monitored.

In addition to the neutron flux, the process quantity capable of monitoring the power distribution in the nuclear reactor, that is, the coolant temperature can be used. Therefore, the coolant temperature signal is used to output the power distribution in the same manner as the neutron flux signal. It is possible to suppress a decrease in thermal tolerance during a distorted transient event.

Further, the thermal allowance in the nuclear reactor changes depending on not only the neutron flux or the coolant temperature but also the core flow rate or the core pressure. These process quantities are also input to the function generator to increase the output. Since the set value for transmitting the suppression signal can be set, the thermal tolerance can be monitored more accurately.

Further, since signals from some neutron flux detectors can be excluded in a range that does not significantly affect the response characteristics of the local region neutron flux signal, even if any neutron flux detector fails. It is possible to accurately monitor the distortion of the output distribution.

Further, except when the predetermined control rod is used, the function of changing the set value for transmitting the output increase suppression signal can be excluded, so that it is not necessary to decrease the set value for transmitting the output increase suppression signal. In the above, it is possible to prevent an erroneous operation of transmitting the output increase suppression signal and suppress a decrease in the driving margin.

Further, since a plurality of circuits for stopping the withdrawal of the control rod are independently provided to allow the logic circuit of 1 out of 2 to pass through, a single failure causes a signal for stopping the withdrawal of the control rod to occur. It is possible to prevent not being sent.

Further, since a plurality of circuits for transmitting the output increase suppression signal are provided independently to allow the logic circuit such as 1 out of2 twice to pass through, a single failure causes the output increase suppression signal to be erroneously generated. It is possible to prevent the signal from being transmitted, and further to prevent the output increase suppression signal from being transmitted when necessary.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS.
Will be explained.

FIG. 1 is a block diagram showing an embodiment of the present invention. The reactor core 1 is divided into a plurality of local regions,
The signals from the neutron flux detector 3 assigned to each local region are averaged by the averaging circuit (A) 4, and the local region neutron flux signal ai is transmitted. Each local region neutron flux signal ai is received by the maximum value detection circuit 5, and the maximum value (hereinafter abbreviated as maximum neutron flux signal) MAX (ai) of each local region neutron flux signal ai is obtained there.

On the other hand, the signals transmitted from all the neutron flux detectors 3 in the reactor core 1 are averaged by the averaging circuit (B) 6, and the averaging circuit (B) 6 outputs the core average neutron flux signals. b is transmitted.

The maximum neutron flux signal MAX (ai) and the average neutron flux signal b are both input to the function generator 7, and as a function of the ratio between the maximum neutron flux signal MAX (ai) and the average neutron flux signal b, The set value f [MAX (ai) / b] is set. The set value f [MAX (ai) / b] is compared with the average neutron flux signal b by the comparator 8, and when the core average neutron flux signal b exceeds the set value f [MAX (ai) / b], An output increase suppression signal is transmitted from the comparator 8.

Further, any local region neutron flux signal ai
Both are calibrated so as to emit the same signal as the average neutron flux signal b during normal operation. As a result, during normal operation, the ratio between the maximum neutron flux signal MAX (ai) and the average neutron flux signal b always indicates 1.0.

That is, the maximum neutron flux signal MAX (ai)
When the ratio between the average neutron flux signal b and the average neutron flux signal b is 1.0, the function generator 7 transmits a set value f [MAX (ai) / b] equivalent to that when the distortion of the output distribution is not considered.

On the other hand, during a transient event in which the output distribution is distorted,
Since at least one of the local region neutron flux signals ai has a value larger than the average neutron flux signal b, the ratio between the maximum neutron flux signal MAX (ai) and the average neutron flux signal b is 1.0. It will show a larger value.

Thus, the maximum neutron flux signal MAX (a
When the ratio between i) and the average neutron flux signal b indicates a value larger than 1.0, the set value f [MAX (ai) / b] smaller than that in normal operation is set in the function generator 7. Set to send. Accordingly, when a transient event in which the output distribution is distorted occurs, the output increase suppression signal can be transmitted before the average neutron flux signal b reaches the set value during normal operation. That is, since the ratio of the maximum neutron flux signal MAX (ai) and the average neutron flux signal b represents the degree of the amount of strain of the output distribution, according to the value of this ratio, the set value f [MAX (ai) / b] can be changed using the function generator 7, and an appropriate set value according to the distortion amount of the output distribution can be transmitted.

On the other hand, among a large number of control rods 2 existing in the reactor core 1, a plurality of control rods belonging to the same control region, in which the deviation of the axial position does not become so large during normal operation, are grouped into the same group. The positional deviation between the control rods 2 is obtained from the signals transmitted from the respective control rod position detectors 9, and the positional deviation is preset by the intra-group control rod position deviation non-permissible determination device 10. If it is determined that the control rod 2 has been exceeded, a pull-out stop signal for the control rod 2 is transmitted, the drive of the pulled-out control rod 2 is stopped, and the power distribution in the reactor core 1 is not greatly distorted. .

As described above, in this embodiment, since the function of transmitting the pulling out stop signal of the control rod 2 is added, the monitoring range of one local area can be expanded to the whole one control area. Thus, it becomes possible to reduce the monitoring region of the local output distribution distortion, and it is possible to reduce the number of averaging circuits (A) 4 for obtaining the local region neutron flux.

FIG. 5 is an enlarged view of the control area portion of FIG. In the case of a large core, there is a possibility that spatial vibration of the power distribution due to xenon may occur. As illustrated in Fig. 5, the reactor core 1 is divided into five control regions, and control is performed for each control region. The output is controlled by the rod 2.

Regarding the first to fourth control areas,
Although there are three control rods in each control region, three control rods belonging to the same control region are normally driven simultaneously with their axial positions aligned. This is to reduce the amount of distortion of the power distribution due to the drive of the control rods during reactor power control.

In the case of the control method shown in FIG. 5,
It is necessary to control each control region independently, and if the positional deviation of the control rods 2 between the control regions is limited, it is considered that the reactor power control will be hindered. Therefore,
If at least one local area is provided in each control area and the amount of strain in the power distribution is monitored, and if the decrease in thermal tolerance is within the allowable value, priority is given to reactor power control, and if the allowable value is exceeded. Is designed to immediately output an output increase suppression signal.

FIG. 6 is an enlarged view of the local area portion of FIG. In the present embodiment, one local area is provided in each control area, and the local area division is set to a minimum of five areas, so that the number of local areas is significantly reduced as compared with the prior art.

FIG. 7 is an explanatory diagram of an output rise suppression signal transmission circuit according to an embodiment of the present invention. From the viewpoint of improving the reliability of the nuclear power plant, in order to prevent the failure of the reactor protection operation due to a single failure or a single malfunction of the detection device, or an unnecessary reactor protection operation, the output increase suppression signal is output from the comparator 8. Independently provide a plurality of circuits for transmitting
2 twice, 2 out of 4, or 2 out o
An output increase suppression signal is transmitted through the logic circuit of f3. This improves the reliability of the output increase suppression signal.

FIG. 8 is an explanatory diagram of a control rod withdrawal stop signal circuit in one embodiment of the present invention. From the viewpoint of improving the reliability of the nuclear power plant, in order to prevent the failure of the control rod withdrawal stop operation due to a single failure of the detection device, the control rod withdrawal stop signal is transmitted from the in-group control rod position deviation non-permissible determination device 10. Multiple independent circuits are provided, 1out
The control rod withdrawal stop signal is transmitted through the logic circuit of of 2. As a result, the reliability of the control rod withdrawal stop signal is improved. FIG. 9 is an explanatory diagram of the bypass allowance circuit of the neutron flux detector 3 (see FIG. 1) input to the averaging circuit (A) 4 (see FIG. 1) in the embodiment of the present invention. Since in-reactor detectors such as the neutron flux detector 3 cannot be replaced while the reactor is in operation, in the case where some of the neutron flux detectors 3 fail, the local region neutron flux signal ai can be monitored. It is necessary to avoid any obstacles. Therefore, the neutron flux detector 3 that is input to the averaging circuit (A) 4 that calculates the local area neutron flux signal ai can be bypassed in consideration of the range that does not significantly affect the local area neutron flux signal ai. The combination is preset.

That is, FIG. 9 shows one local region, and the neutron flux detector 3 used for the detection calculation of the local region neutron flux signal ai of one system is shown by a black circle. The eight neutron flux detectors 3 shown by black circles are divided into four groups as shown by, and two of these four groups are allowed to be bypassed. According to this method, no matter which two sets are bypassed, the response characteristics of the local region neutron flux are not significantly affected.

FIG. 10 shows that, depending on the amount of distortion of the output distribution,
It is explanatory drawing of the function which excludes the function which changes the setting value which transmits an output increase suppression signal. Local region neutron flux signal ai
Is required only when the control rod 2 (see FIG. 1) used for controlling the reactor power is in a drivable state. Therefore, the set value set by the function generator 7 is used only when the designated control rod is in a drivable state, and in other cases, the signal is switched to a preset fixed set value. Thus, the function of changing the set value for transmitting the output increase suppression signal can be excluded except when the predetermined control rod 2 is used.

FIG. 11 is a block diagram relating to setting of set values in another embodiment of the present invention. In the function generator 7, in addition to the maximum neutron flux signal [MAX (ai)] and the average neutron flux signal b, the core flow rate signal c is input, and the maximum neutron flux signal MAX (ai) and the average neutron flux signal are set as set values. The product of the function f [MAX (ai) / b] of the ratio with b and the function g (c) of the core flow rate signal is transmitted as a set value. As a result, the thermal margin of the core can be monitored more accurately. In addition to the core flow rate signal,
A core pressure signal, a core inlet temperature signal, a combination thereof, or the like can be used.

Further, in the case of the pressurized water cooling furnace and the liquid metal cooling furnace, there is a correlation between the power distribution and the cooling water temperature distribution. Therefore, if a plurality of temperature detectors (not shown) can be installed in the reactor core 1 (see FIG. 1),
In the circuit configuration similar to FIG. 1, a temperature detector is used instead of the neutron flux detector 3 (see FIG. 1) to set an appropriate set value of the output increase suppression signal according to the amount of distortion of the output distribution. be able to.

[0064]

According to the present invention, the following effects can be obtained.

(1) The number of local area neutron flux signal detectors can be greatly reduced, and the operator's burden required for the calibration of the detectors can be reduced.

(2) It is possible to monitor the amount of increase in the distortion of the output distribution from the time of normal operation, and to set an appropriate set value at the time of a transient event where the output distribution is distorted.

(3) The malfunction of the output increase suppression signal due to a single failure can be prevented, and the reliability of the output increase suppression signal is improved.

(4) It is possible to prevent the control rod withdrawal stop signal from being transmitted when necessary due to a single failure, and the reliability of the control rod withdrawal stop signal is improved.

(5) Another process amount, that is, the core flow rate or the core pressure is also used for setting the set value for transmitting the output increase suppression signal, so that the thermal margin of the reactor can be monitored more accurately. .

(6) The method of operating the bypass of the neutron detector is specified, and even if some neutron flux detectors cannot be used, the distortion amount of the output distribution can be accurately monitored.

(7) Except when necessary, the function of changing the set value for transmitting the output increase suppression signal can be excluded to prevent a decrease in operating margin.

(8) The output distribution is monitored by another process amount, that is, the coolant temperature, and it is possible to suppress the decrease in the thermal margin at the time of a transient event in which the output distribution is distorted, as in the case of the neutron flux. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an example of arrangement of control rods in a nuclear reactor core.

FIG. 3 is an explanatory diagram of local area division in a conventional example.

FIG. 4 is an explanatory view of a control rod withdrawal sequence at the time of starting the reactor of a conventional example.

FIG. 5 is an enlarged view of a control area portion of FIG.

FIG. 6 is an enlarged view of a local area portion of FIG.

FIG. 7 is an explanatory diagram of an output rise suppression signal transmission logic circuit according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram of a control rod withdrawal stop signal transmission logic circuit according to an embodiment of the present invention.

FIG. 9 is an explanatory diagram of a bypass permission circuit of the neutron flux detector according to the embodiment of the present invention.

FIG. 10 is an explanatory diagram of a function of excluding a function of changing a setting value according to an embodiment of the present invention.

FIG. 11 is a block diagram relating to setting of setting values according to another embodiment of the present invention.

[Explanation of symbols]

1 ... Reactor core, 2 ... Control rod, 3 ... Neutron flux detector, 4
... averaging circuit (A), 5 ... maximum value detecting circuit, 6 ... averaging circuit (B), 7 ... function generator, 8 ... comparator, 9 ... control rod position detector, 10 ... group control rod position Deviation outside tolerance detector.

Claims (12)

[Claims] 1. A control rod position detector that detects the axial position of a control rod in the core of a nuclear reactor, and a control rod position detector that determines whether the axial position deviation between the control rod and the control rod is exceeded. An axial position deviation between the control rods in each of a plurality of groups of the control rods obtained by dividing the inside of the core with a control rod position deviation non-permissible determiner for transmitting a withdrawal stop signal. Is a control rod withdrawal stop means for stopping the withdrawal of the control rod when the allowable value is exceeded, and a plurality of neutron flux detectors for detecting the neutron flux in the core,
In each of a plurality of regions obtained by partitioning the core, an averaging circuit (A) for averaging the neutron flux detected by the neutron flux detector, and the entire neutron flux in the core An averaging circuit (B) for averaging,
A maximum value detection circuit that detects the maximum value of the neutron flux signal (A) when the averaged value of the neutron flux in each of the averaging circuits (A), and the neutron flux signal ( Receive the maximum value of A) and the neutron flux signal (B) when the averaging circuit (B) is a signal with the averaged value of the entire neutron flux in the core,
A function generator that sets a set value as a function of the ratio between the maximum value of the neutron flux signal (A) and the value of the neutron flux signal (B) and transmits the set value; Comparing with the value of the neutron flux signal (B), and having a comparator that transmits an output increase suppression signal in the core when the value of the neutron flux signal (B) exceeds the set value, A reactor protection device characterized by being provided with an output increase suppressing means for suppressing an output increase in the core. 2. The nuclear reactor protection device according to claim 1, further comprising a circuit for calibrating the neutron flux signal (A) to the neutron flux signal (B). 3. The neutron flux signal is provided to the function generator.
The reactor protection device according to claim 1, further comprising means for inputting a core flow rate or a core pressure as a signal in addition to the maximum value of (A) and the neutron flux signal (B). 4. Excluding the number of signals input to the averaging circuit (A) from the plurality of neutron flux detectors up to the number permitted by a predetermined combination. 2. The reactor protection apparatus according to claim 1, further comprising means for averaging only the signals from the remaining neutron flux detectors that are not allowed and are excluded, to obtain the neutron flux signal (A). 5. The nuclear reactor protection apparatus according to claim 1, further comprising means for excluding the output increase suppression means except when the control rod is used in advance. 6. A control rod position detector for detecting an axial position of a control rod in a core of a nuclear reactor and an allowable value of an axial position deviation between the control rod are judged to be over, and the control rod is detected. An axial position deviation between the control rods in each of a plurality of groups of the control rods obtained by dividing the inside of the core with a control rod position deviation non-permissible determiner for transmitting a withdrawal stop signal. Control rod withdrawal stopping means for stopping the withdrawal of the control rod when exceeds an allowable value, a plurality of temperature detectors for detecting the temperature of the coolant in the core, and a plurality obtained by dividing the inside of the core. Averaging circuit (a) for averaging the coolant temperature detected by the temperature detector in each of the regions, and an averaging circuit (b) for averaging the entire coolant temperature in the core. And the respective averaging Road coolant temperature signal when the coolant temperature is the signal averaged value in (a) (a)
Of the coolant temperature signals (a) and the averaging circuit (b) averages all the coolant temperatures in the core. As a signal, the coolant temperature signal (b) is received, and as a function of the ratio between the maximum value of the coolant temperature signals (a) and the value of the coolant temperature signal (b). The function generator that sets the set value of and sends the set value is compared with the set value and the value of the coolant temperature signal (b), and the value of the coolant temperature signal (b) is set to the set value. A reactor protection device, comprising: a comparator that outputs an output increase suppression signal in the core when the value exceeds a value, and an output increase suppression unit that suppresses an output increase in the core. 7. The nuclear reactor protection device according to claim 6, further comprising a circuit for calibrating the coolant temperature signal (a) to the coolant temperature signal (b). 8. In addition to the maximum value of the coolant temperature signal (a) and the coolant temperature signal (b), the core flow rate or core pressure can be input to the function generator as a signal. The reactor protection device according to claim 6, further comprising means. 9. It is permissible to exclude input signals up to the number permitted by a predetermined combination among the signals from the plurality of temperature detectors input to the averaging circuit (a). , Averaging only the signals from the remaining non-excluded temperature detectors to obtain the coolant temperature signal (a)
7. The nuclear reactor protection device according to claim 6, further comprising: 10. The nuclear reactor protection apparatus according to claim 6, further comprising means for excluding the output increase suppression means except when the control rod is used in advance. 11. The pull-out stop signal of the control rod is set to 1
The nuclear reactor protection device according to claim 1 or 6, wherein a plurality of circuits for transmitting through the out of 2 logic circuit are provided independently. 12. The output increase suppression signal is set to 1 out.
of 2 twice, 2 out of 4, or 2 ou
7. The nuclear reactor protection device according to claim 1, wherein a plurality of circuits for transmitting through the logic circuit of tof 3 are independently provided.