JP5512182B2 - Control rod motion monitoring device and control rod motion monitoring method - Google Patents

Description

  The present invention relates to a control rod operation monitoring device and a control rod operation monitoring method for monitoring the operation of a control rod that adjusts reactor power.

  Reactor power control in a nuclear power plant is performed by inserting a number of control rods arranged in the reactor into the reactor, or pulling up the reactor from the reactor to increase or decrease the reactor output. The power control of this nuclear reactor is extremely important control, and various proposals have been made regarding the control of the position of the control rod (see, for example, Patent Document 1 and Patent Document 2).

  Patent Document 1 relates to a control rod position detection device, and when detecting the position of a control rod in the control rod position detection device, the position detection signal is prevented from drifting and giving an erroneous instruction. In order to detect the exact amount of movement during movement, in addition to the position detection signal during control rod movement, pulses during the movement step that occur during driving are detected and counted, and this count value is compared with the position detection signal. Thus, the position of the control rod is correctly determined.

  Further, the control rod position signal obtained from the control rod position detection device is compared with the count value obtained by counting the pulses generated when the control rod is driven, so that the abnormality of the detection of the control rod position is determined.

  That is, the technique disclosed in Patent Document 1 proposes a method for preventing an erroneous instruction for detecting a control rod position and determining a position detection abnormality.

  The one disclosed in Patent Document 2 relates to a control rod position monitoring device, and an abnormality occurs in a signal transmission system or a component of the control rod position monitoring device, and a reactor control panel or the like provided at a location away from the site Thus, when the control rod position display becomes impossible, the control rod position information and the abnormality information can be displayed by the display means newly installed in the part which is not easily affected by the failure.

  That is, an alternative display means is prepared in preparation for the occurrence of an abnormality in the signal transmission system or component of the control rod position monitoring device.

JP-A-8-240692 JP 2007-64656 A

  By the way, regarding the position indication of the control rod position, it is obvious that an erroneous indication may occur due to an abnormality in a position signal transmission system or a component, or an abnormality in the control rod driving device, etc. Also, there is no doubt from experience in actual machine operation, and the method for preventing the occurrence of such an abnormality or eliminating the influence of the abnormality by correcting the detection signal is not limited to the above-mentioned patent documents. Many have been proposed.

  However, if an abnormality occurs in the position indication of the control rod, it is important to know what caused the abnormality in terms of preventing the recurrence of the abnormality or ensuring the reliability of the position indication control. Actually, because the control rod position indicating device is intended to sequentially display the current position of the control rod, it usually does not have a memory function, so the cause of abnormal position indication is verified afterwards. It is extremely difficult to do so, and no effective proposal from such a viewpoint has been made.

  Accordingly, the present invention has been made for the purpose of proposing a control rod operation monitoring device and a control rod operation monitoring method that are effective in investigating the cause when an abnormality occurs in the position display of the control rod.

  In the present invention, the following configuration is adopted as specific means for solving the problem.

In the control rod motion monitoring apparatus according to the first invention of the present application, a plurality of control rod drive shafts arranged in the reactor vessel or a plurality of vibration sensors provided in a control rod housing in which the control rod drive shafts are housed, while creating and outputting an instantaneous maximum data hold for a certain time or sampling period the instantaneous maximum value of the vibration waveform by receiving the vibration signals output from the plurality of vibration sensors, within the predetermined time When an amplitude greater than the instantaneous maximum value in the current holding state appears, at the time of the output of that amplitude, the instantaneous maximum value in the current holding state is updated to the new instantaneous maximum value, and this is held for the above-mentioned fixed time and the instantaneous maximum It is characterized by comprising a signal latch circuit apparatus which generates and outputs the value data, the RBI recorder for performing RBI receives and records instantaneous maximum data from the signal latch circuit device

  As the vibration sensor, means capable of detecting a change in physical quantity accompanying vibration such as an acceleration sensor for detecting a change in acceleration or a sound pressure sensor for detecting a change in sound pressure level can be applied.

  In the second invention of the present application, in the control rod motion monitoring apparatus according to the first invention, a signal waveform having an amplitude equal to or greater than a predetermined threshold value is detected in response to the vibration signals output from the plurality of vibration sensors. A data collection device that collects the raw waveform and outputs it, and receives the raw waveform from the data collection device, analyzes whether the raw waveform is based on the operation of the control rod, It features a data analyzer that creates and outputs it.

  According to a third invention of the present application, in the control rod motion monitoring device according to the first or second invention, the holding time of the instantaneous maximum value in the signal latch circuit device is set to be equal to or longer than a dot cycle of the dot recorder. It is characterized by that.

  In a fourth invention of the present application, in the control rod operation monitoring device according to the first, second or third invention, the signal latch circuit device detects the instantaneous maximum value, and then performs the constant holding time. It is characterized in that it is reset when an instantaneous maximum value equal to or greater than the one instantaneous maximum value is not detected even after elapse of.

  According to a fifth aspect of the present invention, in the control rod motion monitoring device according to the first, second, third or fourth aspect of the present invention, a raw waveform of the vibration signal output from each of the plurality of vibration sensors is received. It is characterized by comprising position detecting means for counting the number of appearances of the raw waveform and detecting the position of the control rod based on the counted number.

  In the control rod motion monitoring method according to the sixth invention of the present application, a counter value display that counts and displays the number of operations of the control rod operation unit that outputs an operation signal to the control rod drive device to simultaneously drive a plurality of control rods. When the deviation between the count value in the unit and each indicated value in the plurality of position display units that respectively indicate the positions of the plurality of control rods or the deviation between the indicated values is a certain value or more, According to any one of the fifth to fifth aspects of the present invention, the cause of the deviation is verified on the basis of the dot recording in the control rod movement monitoring device or on both the dot recording and the analysis data.

  In the present invention, the following effects can be obtained.

(A) According to the control rod operation monitoring apparatus according to the first invention of the present application, the control rod drive shaft disposed in the reactor vessel or the control rod housing in which the control rod drive shaft is accommodated is provided. While receiving the vibration signals output from each of the plurality of vibration sensors and the plurality of vibration sensors, holding the instantaneous maximum value of the vibration waveform for a certain period of time equal to or greater than the sampling period and creating and outputting the instantaneous maximum value data , When an amplitude larger than the instantaneous maximum value currently held is displayed within the above-mentioned fixed time, the instantaneous maximum value currently held is updated to a new instantaneous maximum value at the time when the amplitude is output, and this is updated only for the fixed time. wherein a signal latch circuit apparatus which generates and outputs the instantaneous maximum data hold, that a dotting recorder for performing RBI receives and records instantaneous maximum data from the signal latch circuit device It is.

Here, in order to record raw data (raw waveforms) of vibration signals from a plurality of vibration sensors for a long time, for example, high-speed sampling of about 100 μs is required. In the latch circuit device of the present invention, the instantaneous maximum value of the vibration waveform is held for a certain period of time that is equal to or greater than the sampling period, while the amplitude that is larger than the instantaneous maximum value currently held within the certain period of time appears. At this time, the instantaneous maximum value that is currently held is updated to the new instantaneous maximum value, and this is held for a certain period of time , so the sampling rate (number of samplings) can be suppressed. Therefore, the instantaneous maximum value of the vibration waveform can be accurately captured, and the data volume can be significantly reduced, so that the instantaneous value sampling accuracy is improved. Ku and data capacity less can provide an inexpensive control rod operation monitoring device.

  In addition, since the instantaneous maximum value data is recorded in the hitting point recorder, the cause of the abnormality of the control rod indication value can be easily investigated and verified by referring to the recorded data. It is possible to provide a control rod operation monitoring device having a high height.

  (B) According to the control rod motion monitoring apparatus according to the second invention of the present application, in addition to the effect described in the above (a), the following specific effect can be obtained. That is, according to the present invention, when a signal waveform having an amplitude equal to or greater than a predetermined threshold is detected by receiving vibration signals output from the plurality of acceleration sensors, a raw data waveform is collected and output. Since it has a data analyzer that receives the raw waveform from the data collection device, analyzes whether the raw waveform is based on the operation of the control rod, generates analysis data, and outputs this, for example, When investigating the cause of abnormality of the control rod indication value based on the instantaneous maximum value data in the dot recording recorder, the cause of the abnormality can be investigated with higher accuracy by using the analysis data together. A highly reliable control rod motion monitoring device can be provided.

  (C) According to the control rod motion monitoring device of the third invention of the present application, in addition to the effect described in the above (a) or (b), the following specific effect is obtained. That is, in the present invention, since the holding time of the instantaneous maximum value in the signal latch circuit device is set to be longer than the dot cycle of the dot recorder, the sampling speed (sampling number) in the latch circuit device is reduced. The instantaneous maximum value obtained by the signal latch circuit device can be reliably recorded without being lost, and as a result, a control rod operation monitoring device with higher reliability can be provided at low cost.

  (D) According to the control rod motion monitoring apparatus of the fourth invention of the present application, in addition to the effects described in the above (a), (b) or (c), the following specific effects can be obtained. . That is, the vibration sensor is configured so that the vibration is generated when the control rod is driven based on a normal driving operation, or when the control rod moves without being driven based on the driving operation (for example, movement due to dropping of the control rod). In addition to detecting the vibration waveform of vibration, the vibration waveform of noise vibration generated for some reason is also detected.

  However, some of the vibration waveforms of noise vibrations have an amplitude that is greater than the amplitude of the vibration waveform caused by the movement of the control rod. If the maximum value is held for a long time, even if normal vibration based on the movement of the control rod occurs within this holding time, the instantaneous maximum value cannot be sampled, resulting in a decrease in sampling accuracy. It will be.

  In this case, as in the fourth aspect of the invention, the signal latch circuit device detects an instantaneous maximum value and then the instantaneous maximum value equal to or greater than the instantaneous maximum value even after the fixed holding time has elapsed. By resetting when no noise is detected, the unnecessary instantaneous maximum value holding state based on noise vibration is eliminated at an early stage, and sampling of the vibration waveform caused by the movement of the target control rod is resumed. As a result, the sampling accuracy is improved, and as a result, a more reliable control rod motion monitoring device can be provided.

  Note that when the reset function in the signal latch circuit device eliminates the unnecessary instantaneous maximum value holding state based on noise vibration at an early stage, noise vibration with an amplitude greater than the vibration based on the movement of the control rod occurs. Until the reset function is activated, even if normal vibration based on the movement of the control rod occurs, the instantaneous maximum value is not sampled. However, the interruption of this sampling is controlled by the control rod motion monitoring device. There is no interruption of the function, and hence no deterioration of the reliability of the control rod motion monitoring device. That is, in the control rod motion monitoring device, in parallel with the reset function of the signal latch circuit device as described above, when the signal waveform having an amplitude of a predetermined threshold value or more is detected in the data collection device, the generation is generated. Since the waveform is collected, and the data analyzer analyzes the raw waveform to determine whether or not the raw waveform is based on the operation of the control rod (the raw waveform in the second invention of the present application). Collection / analysis function), even within the retention time of the instantaneous maximum value based on noise vibration (that is, within the sampling interruption time), monitoring of the control rod movement in the control rod movement monitoring device is continued without interruption. This is because the reliability of the control rod operation monitoring device is ensured.

  (E) According to the control rod motion monitoring device of the fifth invention of the present application, the raw waveforms of the vibration signals respectively output from the plurality of vibration sensors are received, and the number of appearances of the raw waveforms is counted. By providing position detection means for detecting the position of the control rod based on the number, the position of the control rod can be confirmed more easily and accurately.

  (F) According to the control rod motion monitoring method of the sixth invention of the present application, the number of operations of the control rod operation unit that outputs an operation signal to the control rod drive device to drive a plurality of control rods at the same time is counted. The deviation between the count value in the counter value display section to be displayed and the respective instruction values in the plurality of position display sections that respectively indicate the positions of the plurality of control rods, or the deviation between the respective instruction values is not less than a certain value. The cause of the deviation is verified based on the dot recording in the control rod motion monitoring device according to any one of the first to fifth inventions or based on both the dot recording and the analysis data. Therefore, for example, when it is determined that the control rod is not driven and the control rod is not moved from the hit point record or both the hit point record and the analysis data, the specific control rod When the deviation between the corresponding instruction value and each instruction value corresponding to each of the other control rods is large, or when the deviation between the instruction value corresponding to a specific control rod and the count value is large, both of the specific control It is possible to easily and quickly investigate and verify the cause of the above deviation, such as determining that an abnormality has occurred in the transmission system of the indicated value corresponding to the bar or the corresponding position display section, and Can improve the reliability of the drive control of the control rod itself.

  In particular, upon confirming the deviation between the count value in the counter value display unit that counts and displays the number of operations of the control rod operation unit, and the indication values in the plurality of position display units that respectively indicate the positions of the plurality of control rods, The position detecting means according to the fifth invention is used in combination, and the reliability of the deviation is ensured by comparing the position of the control rod detected by the position detecting means with each indicated value in the position display section. More accurate control rod operation monitoring is realized.

It is a system diagram of a control rod control system including a control rod motion monitoring device according to an embodiment of the present invention. It is a layout of control rods in a nuclear reactor vessel. It is explanatory drawing of the waveform process in a control rod operation | movement monitoring apparatus.

  Hereinafter, the present invention will be specifically described based on preferred embodiments.

  FIG. 1 shows a control rod control system including a control rod motion monitoring device 7 according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a reactor vessel, and a plurality (33 in this embodiment) of control rod drive shafts 3 are arranged at a top portion of the reactor vessel 1 in a predetermined arrangement pattern (see FIG. 2). Has been placed. The control rod drive shaft 3 is composed of a different-diameter straight rod body having latching grooves formed at a predetermined pitch over its entire length, and is moved downward or up by a control rod drive device 4 described later, A control rod (not shown) connected to the lower end of the reactor is inserted or pulled up into the reactor vessel 1 to control the reactor output, and is housed in a cylindrical control rod housing 2. Is arranged in.

  The control rod housing 2 is provided with a control rod drive device 4 described below at a portion near its lower end and a control rod position indicating device 5 described below at a portion near its upper end. An acceleration sensor 10 as a vibration sensor, which is one of the components of the present invention, is disposed at the upper end of the housing 2.

  The control rod drive device 4 raises or lowers the control rod drive shaft 3 step by step and holds it fixedly at a predetermined position so as to surround the control rod drive shaft 3. A plurality of (for example, three) latching claws 44 arranged at equal intervals in the circumferential direction are arranged in two upper and lower stages at predetermined intervals in the axial direction of the control rod drive shaft 3, and each latching On the outside of the claw 44, a pulling coil 41, a movable gripping coil 42 and a fixed gripping coil 43 are arranged in multiple stages so as to surround each of the hooking claws 44. The coils 41 to 43 are controlled to be excited and demagnetized by a control signal from a control rod drive device control panel 8 which will be described later, so that the hooking claws 44 are actuated in a predetermined order to control the control rod drive shaft. 3 can be raised or lowered step by step.

  The control rod position indicating device 5 is configured by arranging a plurality of coils 51 so as to surround the control rod drive shaft 3, and when the control rod drive shaft 3 moves in the coil 51. By detecting the generated induced voltage, the position of the control rod drive shaft 3 is detected, and this is output to a control rod position indicating device control panel 9 described later as a position instruction signal corresponding to the position of the control rod. It is configured.

  The acceleration sensor 10 corresponds to a “vibration sensor” in the claims, and is attached to the upper end of the control rod housing 2 so as to reduce vibration caused by the movement of the control rod drive shaft 3 as an acceleration. This is detected as a change, and the vibration waveform (raw waveform; see FIG. 3A) is output to the control rod motion monitoring device 7 described later via the acceleration signal output terminal block 11.

  In this embodiment, the acceleration sensor 10 is used to detect the vibration accompanying the movement of the control rod drive shaft 3, but the present invention is not limited to this configuration. In the embodiment, a sound pressure sensor that detects a change in the sound pressure level accompanying the vibration of the control rod drive shaft 3 is employed, and the sound pressure waveform can also be used.

  On the other hand, in FIG. 1, reference numeral 6 denotes a central control panel, which includes a control rod operation unit 61 that performs a drive operation of the control rod drive shaft 3, and is provided for each operation of the control rod operation unit 61. A counter value display unit 62 including a plurality (four in this embodiment) of display units 62A to 62D for counting and displaying the count value, and the position of the control rod obtained from the position of the control rod drive shaft 3 are displayed. A position display unit 63 including a plurality of (four in this embodiment) display units 63A to 63D is provided. The display units 62A to 62D of the counter value display unit 62 correspond to the display units 63A to 63D of the position display unit 63, respectively.

  Here, an example of the arrangement pattern of the control rod drive shaft 3 in the reactor vessel 1 and the grouping thereof will be described with reference to FIG.

  The reactor vessel 1 of this embodiment includes 33 control rod drive shafts 3 as shown in FIG. Of these control rod drive shafts 3, the control rod drive shaft 3 indicated by a white double circle is the control rod drive shaft 3 corresponding to the control rod for reactor power control, and the control indicated by a black double circle is provided. The rod drive shaft 3 is a control rod drive shaft 3 corresponding to the control rod for stopping the reactor, and these two kinds of control rod drive shafts 3 are arranged in the pattern shown in FIG.

  For example, the 21 control rod drive shafts 3 corresponding to the output control control rods are divided into four banks, and the control rod drive shafts 3 belonging to each bank are further grouped by a predetermined number. Yes. The twelve control rod drive shafts 3 corresponding to the stop control rods are divided into two banks, and a predetermined number of control rod drive shafts 3 belonging to each bank are further appropriately grouped. .

  Each of the control rod drive shafts 3 divided into banks is controlled to operate for each bank. In this embodiment, as shown in FIG. 2, the control rod drive corresponding to the control rod for stopping. The following control will be described by taking four control rod drive shafts (indicated as “3A” in FIG. 2) belonging to one bank of the shafts 3 as an example.

  When the control rod operating unit 61 is operated, the respective operation signals are input to the control rod drive devices 4 of the four control rod drive shafts 3 belonging to the same bank via the control rod drive device control panel 8. These four control rod drive shafts 3 are simultaneously driven in the upward or downward direction. In this case, the number of operations of the control rod operation unit 61 is counted in the control rod drive device control panel 8, and the count value is displayed on each display unit 62A to 62D of the counter value display unit 62 (this In the embodiment, each of the display units 62A to 62D shows a state where “222” is displayed).

  Further, in each control rod position indicating device 5 of the four control rod drive shafts 3 belonging to the same bank, the position of the control rod drive shaft 3 corresponding to the movement of the control rod drive shaft 3, that is, The position of the control rod is detected and input to the control rod position indicating device control panel 9 as a position display signal, and is converted into a digital signal by the control rod position indicating device control panel 9. In the position display parts 63A-63D, it is displayed as the position instruction value of each control rod.

  Here, if the mechanism, control system, and signal transmission system related to the movement of the control rod drive shaft 3 (that is, movement of the control rod) are normal, the count value of the counter value display unit 62 and the position display are displayed. The position indication values of the position display units 63A to 63D of the unit 63 should match, but in the example of this embodiment, the count values and the display of the three position display units 63A to 63C are both “222”. On the other hand, only one position display portion 63D is displayed as “198”, and the deviation of the display value between them is large.

  Obviously, it is possible to immediately determine that an abnormality has occurred in any one of the mechanism unit, the control system, and the signal transmission system by looking at the deviation of the display value. And as above-mentioned, various countermeasures are proposed conventionally about such abnormality determination.

  However, as described above, no effective proposal has been made for the investigation and verification method of the cause of the occurrence of such a display with a deviation.

  An effective means for investigating and verifying the cause of such a deviation display is the control rod motion monitoring device 7 described below. As shown in FIG. 1, the control rod motion monitoring device 7 includes four acceleration sensors 10, acceleration signal output terminal blocks 11, and signals provided in four control rod housings 2 belonging to the same bank. A latch circuit device 71, a dot recording meter 72, a data collecting device 73, and a data analyzer 74 are provided.

  The acceleration sensor 10 is attached to the upper end of the control rod housing 2 as described above, detects the vibration accompanying the movement of the control rod drive shaft 3 as a change in acceleration, and outputs the vibration waveform. . The vibration waveform (raw waveform) detected on each control rod housing 2 side output from each acceleration sensor 10 is input to the signal latch circuit device 71 via the acceleration signal output terminal block 11.

  In FIG. 1, signal transmission after the acceleration signal output terminal block 11 is indicated by a single line, but this will be described below by taking one of the vibration waveforms from each acceleration sensor 10 as an example. Needless to say, the vibration waveform from each acceleration sensor 10 is actually input to the signal latch circuit device 71.

  In the control rod motion monitoring device 7, two processes described below are performed in parallel.

  The first process is a process for acquiring an instantaneous maximum value of a vibration waveform and a dot recording process using the signal latch circuit device 71 and the dot recording meter 72. The second processing is raw waveform collection processing using the data collection device 73 and the data analyzer 74 and analysis processing thereof. Note that the second process is a complementary process for improving the reliability of the first process, and does not always have to be performed together with the first process. There may be a case where only the above processing is performed. Hereinafter, the first and second processes will be described individually.

"First process"
The signal latch circuit device 71 receives a raw waveform (see FIG. 3A) as a vibration signal from the acceleration sensor 10 input through the acceleration signal output terminal block 11, and receives instantaneous maximum value data ( (See FIG. 3B).

  That is, in order to record the raw data of the vibration signal from the acceleration sensor 10 for a long time, for example, high-speed sampling of about 100 μs is required, so a huge amount of recording medium is required, which is not realistic. Therefore, in the signal latch circuit device 71 of this embodiment, in order to reduce the number of samplings (sampling speed) and at the same time ensure the sampling accuracy, the vibration waveform output from the acceleration sensor 10 is received. The instantaneous maximum value is detected and held for a certain period of time to generate instantaneous maximum value data.

  Specifically, when a raw waveform as shown in FIG. 3A is input, the raw waveform is subjected to envelope conversion to create an envelope waveform as shown in FIG. Then, the maximum value of the amplitude of the envelope waveform is regarded as an instantaneous maximum value, and this is held for a certain time (for example, 60 seconds). If an amplitude greater than the instantaneous maximum value in the current holding state appears within this holding time, the previous instantaneous maximum value in the holding state is updated to a new instantaneous maximum value at the time when the amplitude appears. This is newly held for a certain period of time. By repeating such sampling and holding operations each time a new amplitude appears, step-like instantaneous maximum value data as shown in FIG.

  In addition, when no amplitude larger than the instantaneous maximum value in the current holding state appears within the holding time, as shown in FIG. 3B, at the time when the holding time has elapsed (point a). It resets, waits for the appearance of a new instantaneous maximum value, and control is started by the appearance.

  Here, as described above, the reason why the sampling of the vibration waveform is reset at the time when the holding time elapses when an amplitude larger than the instantaneous maximum value currently in the holding state does not appear is as follows. It is. That is, the acceleration sensor 10 not only detects the acceleration when the control rod moves based on a normal driving operation, but also detects the acceleration of noise vibration generated for some reason. However, if the instantaneous maximum value of such noise vibration is held for a long time, even if normal vibration based on the movement of the control rod occurs within this holding time, the instantaneous maximum value cannot be sampled. As a result, the sampling accuracy is lowered. For this reason, after detecting the instantaneous maximum value, if no instantaneous maximum value is detected that is equal to or greater than the instantaneous maximum value in the current holding state after the holding time has elapsed, the sampling is reset and the normal vibration based on the movement of the control rod This is because it is possible to sample the vibration waveform in order to increase the sampling accuracy.

  The instantaneous maximum value data obtained in the signal latch circuit device 71 as described above is automatically input to the dot recording recorder 72. In this dot recording meter 72, the input instantaneous maximum value data is dot-recorded at a predetermined cycle and held. In this case, by setting the dot recording cycle in the dot recorder 72 shorter than the holding time of the instantaneous maximum value in the signal latch circuit device 71 (see FIG. 3B), the latch circuit device 71. The instantaneous maximum value obtained by the signal latch circuit device 71 can be recorded without fail while reducing the sampling number (sampling speed).

"Second process"
The signal latch circuit device 71 has the function of obtaining the instantaneous maximum value from the envelope waveform obtained by envelope conversion of the vibration waveform as described above, and obtaining the instantaneous maximum value data based on this, but this sampling function In addition, a through circuit function is provided so that the raw waveform of vibration input from the acceleration signal output terminal block 11 side can be output to the data collecting device 73 as it is.

  The data collection device 73 collects a raw waveform of vibration input via the signal latch circuit device 71, but does not collect all the input raw waveforms but has an amplitude equal to or greater than a certain threshold. Only raw waveforms are collected. It is known from experience that the amplitude of vibration accompanying the movement of the control rod is greater than a certain level (that is, greater than or equal to the above threshold), so when a vibration waveform having an amplitude exceeding this threshold appears. This is because collecting the raw waveform of this vibration is considered to be sufficient for the monitoring function of the control rod operation.

  Specifically, the data collection device 73 is always in a waiting state for a trigger using an input of a raw waveform having an amplitude greater than or equal to the threshold as a trigger signal. When a raw waveform having an amplitude exceeding the threshold is input to the data collection device 73, the raw waveform is collected and the trigger waiting state is repeated.

  In this case, the raw waveforms from the four acceleration sensors 10 may be uniformly collected, or a control rod in which an abnormality is recognized in the position display value on the position display unit 63 of the central control panel 6 may be used. Only the raw waveform from the acceleration sensor 10 corresponding to the bank to which it belongs may be collected, and particularly in the latter case, there is an advantage that it can contribute to a reduction in data capacity.

  The data analyzer 74 receives the raw waveform input from the data collection device 73, compares the input waveform with vibration waveform data that is caused by the movement of the control rod held in advance, and the input waveform is Analyze whether the vibration waveform is really caused by the movement of the control rod. In addition to being held in the data analyzer 74, the analysis result is output to a printer as necessary, and is also held as document data.

  By the way, the position of the control rod is obtained by converting the position of the control rod drive shaft 3 detected by the control rod position indicating device 5 into a digital signal in the control rod position indicating device control panel 9 as described above. In addition, the position indication values of the control rods are displayed on the position display portions 63A to 63D of the position display portion 63. In addition, the position indication values can be obtained from the vibration waveform of the vibration detected by the acceleration sensor 10. it can.

  That is, as described above, the raw waveform of vibration detected by each acceleration sensor 10 passes through the signal latch circuit device 71 and is input to the data collection device 73 (see FIG. 3A). On the other hand, the movement of the control rod drive shaft 3 is performed step by step by the control rod drive device 4, so that the vibration waveform accompanying the movement of the control rod drive shaft 3 is also one step of the control rod drive shaft 3. Appears on every move. That is, the number of movements of the control rod drive shaft 3 and the number of raw waveforms from the acceleration sensor 10 coincide with each other. Therefore, by counting the number of raw waveforms input to the data collecting device 73, the above control is performed. The position of the rod drive shaft 3 can be easily confirmed, and this can be displayed on the data analyzer 74 and visually confirmed.

  It should be noted that such a control rod position detection method based on the number of raw vibration waveforms can be used as an alternative method of the control rod position indicating device 5. By using together with the position indicating device 5, the control rod position acquired based on the raw waveform is compared with the display values displayed on the position display portions 63 </ b> A to 63 </ b> D of the position display portion 63, thereby the control rod position. Abnormality determination of the vibration transmission system from the position indicating device 5 to the position display unit 63 or the mechanism of the position display unit 63 can be easily and accurately performed. According to such usage, the display on the position display unit 63 is performed. The reliability of information, and hence the reliability of control rod operation monitoring will be improved.

  The above is the configuration and operation characteristics of the control rod motion monitoring device 7. Here, a method for investigating the cause of the occurrence of the display with the deviation as described above using the control rod motion monitoring device 7 and verifying it will be described.

  When the deviation between the count value in the counter value display unit 62 of the central control panel 6 and the indicated values in the position display units 63A to 63D of the position display unit 63 of the central control panel 6 is not less than a certain value, The cause of the deviation is verified based on the dot recording of the dot recording meter 72 in the control rod motion monitoring device 7 or based on both the dot recording and the analysis data of the data analyzer 74.

  For example, when it is determined that the control rod is not driven and the control rod is not moving from the hit point record or from both the hit point record and the analysis data, it corresponds to a specific control rod. There is a large deviation between the instruction value (in this embodiment, the display value of the position display unit 63D) and each instruction value corresponding to each of the other control rods (in this embodiment, the display values of the position display units 63A to 63C). In the embodiment, there is a difference of 24 steps), or an indication value corresponding to a specific control rod (in this embodiment, a display value of the position display unit 63D) and a corresponding display unit of the counter value display unit 62 When the deviation of the count value at 62D is large, it is easily and accurately determined that an abnormality has occurred in the transmission system of the instruction value corresponding to the specific control rod or the corresponding position display portion 63D. Rukoto can.

  As a synergistic effect, there is a difference between the count value in the counter value display unit 62 of the central control panel 6 and the instruction values in the position display units 63A to 63D of the position display unit 63 of the central control panel 6. The cause of the increase can be easily and quickly investigated and verified, and as a result, the reliability of the drive control of the control rod itself can be improved.

1 ·· Reactor vessel 2 ·· Control rod housing 3 ·· Control rod drive shaft 4 ·· Control rod drive 5 ·· Control rod position indicating device 6 ·· Central control panel 7 ·· Control rod operation monitoring device 8 ·・ Control rod drive device control panel 9 ・ ・ Control rod position indicating device control panel 10 ・ ・ Acceleration sensor (vibration sensor)
11 ..Acceleration signal output terminal block

Claims (6)

A plurality of vibration sensors provided in a plurality of control rod drive shafts arranged in the reactor vessel or a control rod housing in which the control rod drive shafts are housed;
While receiving the vibration signal output from each of the plurality of vibration sensors, the instantaneous maximum value of the vibration signal is held for a certain period of time that is equal to or greater than the sampling period, and the instantaneous maximum value data is generated and output, while within the certain period of time When an amplitude larger than the instantaneous maximum value in the current holding state appears, at the time of the output of the amplitude, the instantaneous maximum value in the currently holding state is updated to a new instantaneous maximum value, and this is held for the above-mentioned fixed time and the instantaneous maximum A signal latch circuit device for creating and outputting value data ; and
A dot recorder that receives the instantaneous maximum value data from the signal latch circuit device and performs dot recording;
A control rod operation monitoring device comprising: In claim 1,
A data collection device that receives the vibration signals output from the plurality of vibration sensors, collects the raw waveform when a vibration signal having an amplitude equal to or greater than a predetermined threshold is detected, and outputs the waveform;
A data analyzer is provided that receives the raw waveform from the data collection device, analyzes whether the raw waveform is based on the operation of the control rod, generates analysis data, and outputs the analysis data. Control rod motion monitoring device. In claim 1 or 2,
The control rod motion monitoring device according to claim 1, wherein the holding time of the instantaneous maximum value in the signal latch circuit device is set to be equal to or longer than a dot cycle of the dot recorder. In claim 1, 2 or 3,
The signal latch circuit device is reset when a momentary maximum value equal to or greater than the momentary maximum value is not detected even after the fixed holding time has elapsed after detecting a momentary maximum value. Control rod operation monitoring device. In claim 1, 2, 3 or 4,
Receiving a raw waveform of a vibration signal output from each of the plurality of vibration sensors, counting the number of appearances of the raw waveform, and comprising position detecting means for detecting the position of the control rod based on the counted number; Control rod motion monitoring device.   Outputs an operation signal to the control rod drive unit to drive multiple control rods at the same time. Counts the number of operations of the control rod operation unit and displays the count value, and indicates the position of the multiple control rods. In the control rod motion monitoring device according to any one of claims 1 to 5, when a deviation from each indicated value in the plurality of position display units or a deviation between each indicated value is a certain value or more. A control rod motion monitoring method characterized by verifying the cause of the deviation based on the hit point record or based on both the hit point record and the analysis data.

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