Abstract:
There is provided a device for monitoring an operation of a nuclear plant, including: a functional integration VDU having a regular-use-system VDU that monitors the operation of the plant under normal conditions, and a security-system VDU that leads to a safe state when the plant is in an abnormal state; and a security-system VDU that leads to a safe state when the plant is in an abnormal state. The functional integration VDU is mounted to a first operating console, the security-system VDU is mounted to a second operating console, and thereby an increase in the size of the operating consoles in the nuclear plant is suppressed, and increased ease of operation is enabled.

Description:
FIELD 
     The present invention relates to a device for monitoring an operation of a nuclear plant capable of operating a safety system and a regular use system (non-safety system). 
     BACKGROUND 
     There is a need for an instrumentation and control system that has high reliability and may be easily operated in order to stably operate a nuclear power plant. An application of a central control panel of a software operation type, and digitization of control-system and security-system equipment is indispensable to ensure the instrumentation and control system. The instrumentation and control system in the nuclear power plant includes a central control panel used when an operator monitors an operation of the plant, and the central control panel includes a regular-use-system (non-security-system) device which measures a process amount of the plant to monitor an operation of auxiliary equipment such as a pump and a valve, and a security-system device which safely suspends the plant when the plant is in an abnormal state. 
     Heretofore, a central control room accommodates a regular-use-system device for monitoring an operation and a security-system device for monitoring an operation which are disposed side by side in an approximately linear shape in the same operating console serving as the central control panel. 
     As an example of the device for monitoring operations of the nuclear plant, a device is disclosed in Patent Literature 1 below. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: Japanese Patent No. 2947840 
     SUMMARY 
     Technical Problem 
     Heretofore, since a regular-use-system device for monitoring an operation and a security-system device for monitoring an operation have been disposed in the same operating console in a central control room, the entire operating console needs to be robust. Therefore, a manufacturing cost increases, and the device increases in size. That is, the security-system device for monitoring an operation is used to safely suspend the nuclear plant when the nuclear plant is in an abnormal state, and thus needs to be manufactured to have a structure superior in a seismic resistance. On the other hand, the regular-use-system device for monitoring an operation is used to monitor an operation of auxiliary equipment of the nuclear plant, and thus may have a structure having a general seismic resistance. However, since the security-system and regular-use-system devices for monitoring an operation are disposed in the same operating console, the entire operating console of the security-system and the regular-use-system needs to have a structure superior in a seismic resistance, which entails an increase in manufacturing cost and an increase in size of the device, and there is a fear that an indoor passage space is limited. 
     The invention is made to resolve the above-described issue, and an object of the invention is to provide a device, for monitoring an operation of a nuclear plant, capable of facilitating an operation by suppressing an increase in size of an operating console in the nuclear plant. 
     Solution to Problem 
     In order to achieve the object, there is provided a device for monitoring an operation of a nuclear plant, including: a first operating console having a regular-use-system control function of monitoring an operation of the plant in a normal state and a security-system control function of leading the plant in an abnormal state to a safe state; and a second operating console having a security-system control function of leading the plant in an abnormal state to a safe state. 
     Accordingly, when a first operating console having a regular-use-system control function and a security-system control function, and a second operating console having a security-system control function are provided, only the second operating console may have a structure superior in a seismic resistance, and the first operating console may have a structure having a general seismic resistance. Thus, an increase in size of an operating console due to seismic strengthening may be suppressed, and an operation may be facilitated. 
     The device for monitoring an operation of a nuclear plant according to the present invention is characterized that the first operating console is disposed at a center of a central control room, and the second operating console is disposed near a wall surface of the central control room to be adjacent to the first operating console. 
     Accordingly, by appropriately disposing the respective operating consoles, it is possible to attempt an efficient use of a space within a central control room. 
     The device for monitoring an operation of a nuclear plant of the invention is characterized in that the plant in an abnormal state is led to a safe state using the security-system control function of the second operating console when the security-system control function in the first operating console is in an abnormal state, and a block device is provided to inhibit an operation of the security-system control function by the first operating console when the security-system control function in the first operating console is in an abnormal state. 
     Accordingly, when the security-system control function in the first operating console is in a normal state, the plant in an abnormal state is led to a safe state using the security-system control function. On the other hand, when the security-system control function in the first operating console is in an abnormal state, an inhibition an operation of the security-system control function by the first operating console is prevented using the block device, and the plant in an abnormal state is led to a safe state using the security-system control function of the second operating console. In this case, using the first operating console, an operation of the plant in a normal state may be monitored, and the plant in an abnormal state may be controlled, and thus an operation in the nuclear plant may be facilitated. In addition, when the security-system control function in the first operating console is in an abnormal state, an inhibition of an operation of the security-system control function of the second operating console by the security-system control function of the first operating console is prevented using the block device, and the plant in an abnormal state is led to a safe state using the security-system control function of the second operating console, and thus the plant in an abnormal state may be reliably controlled, and a high security of an operation control may be ensured. 
     Advantageous Effects of Invention 
     According to the device for monitoring an operation of a nuclear plant of the invention, a first operating console having a regular-use-system control function and a security-system control function, and a second operating console having a security-system control function are provided, and thus only the second operating console may have a structure superior in a seismic resistance, and the first operating console may have a structure having a general seismic resistance. As such, an increase in size of an operating console due to seismic strengthening may be suppressed, and an operation may be facilitated. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic diagram illustrating a central control room in a device for monitoring an operation of a nuclear plant according to an embodiment of the invention. 
         FIG. 2  is a schematic diagram illustrating a functional integration VDU and a security-system VDU in the device for monitoring an operation of a nuclear plant of the embodiment. 
         FIG. 3  is a schematic diagram illustrating a control block in the device for monitoring an operation of a nuclear plant of the embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, a preferred embodiment of a device for monitoring an operation of a nuclear plant according to the invention will be described in detail with reference to accompanying drawings. It should be noted that the invention is not limited to the embodiment. 
     Embodiment 
       FIG. 1  is a schematic diagram illustrating a central control room in a device for monitoring an operation of a nuclear plant according to an embodiment of the invention,  FIG. 2  is a schematic diagram illustrating a functional integration VDU and a security-system VDU in the device for monitoring an operation of a nuclear plant of the embodiment, and  FIG. 3  is a schematic diagram illustrating a control block in the device for monitoring an operation of a nuclear plant of the embodiment. 
     In the device for monitoring an operation of a nuclear plant of the embodiment, as illustrated in  FIGS. 1 and 2 , a central control room  11  is an almost sealed room, and includes a first operating console  12 , a second operating console  13 , an operation command console  14 , and a large-size display panel  15 . In this case, the large-size display panel  15  is disposed in the foremost position, and the first operating console  12  is disposed to face a front face of the large-size display panel  15  toward the large-size display panel  15 . In addition, the second operating console  13  is disposed on a wall surface of the central control room  11  to be adjacent to the first operating console  12 . The operation command console  14  is disposed behind the first operating console  12  to face a front face of the large-size display panel  15  toward the large-size display panel  15 . 
     That is, in the central control room  11 , the first operating console  12  and the operation command console  14  are disposed in the center, and the second operating console  13  is disposed near a wall surface of the central control room  11  to be adjacent to the first operating console  12 . Specifically, the operation command console  14  is disposed at an approximately central portion of a circle drawn in a central part of the central control room  11 , and the first operating console  12  is disposed to form an arc on the circle at a side of the large-size display panel  15 . The second operating console  13  is disposed to be in close contact with a wall surface of the central control room  11  on an outside of the circle. 
     A functional integration VDU  21  is mounted to the first operating console  12 , and a security-system VDU  22  is mounted to the second operating console  13 . The functional integration VDU  21  has a regular-use-system control function of monitoring an operation of a plant when the plant is in a normal state, and a security-system control function of safely suspending (leading to a safe state) a plant when the plant is in an abnormal state. On the other hand, the security-system VDU  22  is a VDU for backing up the security-system control function in the functional integration VDU  21 , and has a security-system control function of safely suspending (leading to a safe state) a plant when the plant is in an abnormal state. The VDU refers to a visual display unit. 
     In addition, the first operating console  12  (functional integration VDU  21 ) and the second operating console  13  (security-system VDU  22 ) are operated by an operator. On the other hand, the operation command console  14  is operated by a shift supervisor who gives instructions to an operator, and a VDU for administrative use  23  is mounted thereto. In the embodiment, the operation command console  14  includes a supervision command console  14   a  (VDU for supervisor  23   a ) and a technology command console  14   b  (VDU for technician  23   b ). 
     In this case, the second operating console  13  to which the security-system VDU  22  is mounted has a structure covered with a hard iron plate to have a structure superior in a seismic resistance. On the other hand, the first operating console  12  to which the functional integration VDU  21  having the regular-use-system control function and the security-system control function is mounted may have a structure having a general seismic resistance, and does not need to have a structure covered with a hard iron plate. 
     In the central control room  11  in the device for monitoring an operation of a nuclear plant of the embodiment, a block device is provided to inhibit (inhibition of an operation) an operation of the security-system control function by the functional integration VDU  21  when the functional integration VDU  21  is in an abnormal state. Herein, the block device is provided in the second operating console  13  (security-system VDU  22 ). 
     The block device includes an AND circuit (software) to which a plant suspension signal (plant operating signal) output from the functional integration VDU  21  and a block signal output from the security-system VDU  22  are input. In this case, a plant suspension signal output from the functional integration VDU  21  and the security-system VDU  22 , and a block signal output from the security-system VDU  22  are manual signals output by an operation of an operator. The nuclear plant is suspended when one of a plant manual suspension signal output from the functional integration VDU  21  and the security-system VDU  22 , and a plant automatic suspension signal output based on a process amount of the plant is output. 
     That is, as illustrated in  FIG. 3 , the functional integration VDU  21  has a function of a security-system VDU  31  and a function of a regular-use-system (non-security-system) VDU  32 . That is, as the security-system VDU  31 , an ON operating switch  33  and an OFF operating switch  34  are provided to operate and suspend various devices in a security-system equipment  51 . As the regular-use-system VDU  32 , an ON operating switch  35  and an OFF operating switch  36  are provided to operate and suspend various devices in a regular-use-system equipment  52 . In this case, herein, the respective operating switches  33  and  34  in the security-system VDU  31 , and the respective operating switches  35  and  36  in the regular-use-system VDU  32  are illustrated by an example. However, actually, a plurality of switches are provided as each of the operating switches according to various devices. 
     The security-system VDU  22  includes an ON operating switch  37  and an OFF operating switch  38  that operate and suspend various devices in the security-system equipment  51 , and includes a cutoff operating switch  39  that operates the block device. In this case, herein, the respective operating switches  37 ,  38 , and  39  in the security-system VDU  22  are illustrated by an example. However, actually, a plurality of switches are provided as each of the operating switches according to various devices. 
     A signal of the ON operating switch  33  of the security-system VDU  31  is input to an AND circuit  41 . In addition, a signal of the cutoff operating switch  39  of the security-system VDU  22  is input to the AND circuit  41  via a latch circuit  42  and a NOT circuit  43 . In this case, when the cutoff operating switch  39  of the security-system VDU  22  is not operated, an ON signal “ 0 ” is inverted in the NOT circuit  43  to be input to the AND circuit  41  as an ON signal “ 1 ”, and in response to the ON operating switch  33  of the security-system VDU  31  being operated and an ON signal “ 1 ” being input to the AND circuit  41 , the AND circuit  41  outputs an ON signal “ 1 ”. 
     A signal output from the AND circuit  41  is input to an OR circuit  44 . In addition, a signal output from the ON operating switch  37  and the OFF operating switch  38  of the security-system VDU  22  is input to the OR circuit  44 . In this case, when an ON signal “ 1 ” is input from the AND circuit  41  or an ON signal “ 1 ” is input from the ON operating switch  37  to the OR circuit  44 , the OR circuit  44  outputs an ON signal “ 1 ”. In the security-system VDU  22 , description is made on the assumption that an ON signal “ 1 ” is output when the ON operating switch  37  is operated, and an ON signal “ 0 ”, that is, an OFF signal “ 1 ” is output when the OFF operating switch  38  is operated, and none of the switches is operated. 
     On the other hand, an ON signal “ 1 ” is inverted in the NOT circuit  43  to be input to the AND circuit  41  as an ON signal “ 0 ” when the cutoff operating switch  39  of the security-system VDU  22  is operated, and the AND circuit  41  does not output an ON signal “ 1 ” even when the ON operating switch  33  of the security-system VDU  31  is operated and an ON signal “ 1 ” is input to the AND circuit  41 . That is, between the security-system VDU  31  of the functional integration VDU  21  and the security-system VDU  22 , processing of the security-system VDU  22  is given priority. 
     The respective operating switches  33  and  34  of the security-system VDU  31  and the respective operating switches  35  and  36  of the regular-use-system VDU  32  in the functional integration VDU  21 , and the respective operating switches  37 ,  38 , and  39  in the security-system VDU  22  described in the foregoing are manually operated by an operator. When the operator detects that an abnormality occurs in the security-system equipment  51 , the security-system equipment  51  is safely suspended by outputting a manual suspension signal. 
     On the other hand, multiple sensors are provided to detect a state of various devices in the nuclear plant, and a control device (not illustrated) monitors an operational state based on a detection result of each sensor. When the control device detects that an abnormality occurs in the security-system equipment  51 , the security-system equipment  51  is safely suspended by outputting an automatic suspension signal. 
     An ON signal of the automatic suspension is input to an OR circuit  45 , and is input to an AND circuit  47  via a NOT circuit  46 . In addition, an OFF signal of an automatic suspension is input to an OR circuit  48 , and is input to an AND circuit  50  via a NOT circuit  49 . A signal output from the AND circuit  50  is input to the OR circuit  45 , and a signal output from the OFF operating switch  34  is input to the OR circuit  48  via the AND circuit  47 . 
     In this case, when the control device outputs an ON signal of an automatic suspension, an ON signal “ 1 ” is input to the OR circuit  45 , and the OR circuit  45  outputs an automatic suspension ON signal “ 1 ” for suspending the security-system equipment  51  irrespective of a signal from the functional integration VDU  21  or the security-system VDU  22 . In addition, when an ON signal of a manual suspension is output from the functional integration VDU  21  or the security-system VDU  22  by an operation of an operator, an ON signal “ 1 ” is input to the OR circuit  45 , and the OR circuit  45  outputs an automatic suspension ON signal “ 1 ” for suspending the security-system equipment  51  irrespective of an ON signal of an automatic suspension. 
     On the other hand, when the control device does not output an ON signal of an automatic suspension, an ON signal “ 0 ” is input to the OR circuit  45 . In addition, when an ON signal of a manual suspension is not output from the functional integration VDU  21  or the security-system VDU  22  without an operation of an operator, an ON signal “ 0 ” is input to the OR circuit  45 . For this reason, the OR circuit  45  does not output an automatic suspension ON signal “ 1 ” for suspending the security-system equipment  51 . 
     In addition, when the control device outputs an OFF signal of an automatic suspension, an OFF signal “ 1 ” is input to the OR circuit  48 , and the OR circuit  48  outputs an automatic suspension OFF signal “ 1 ” for not suspending the security-system equipment  51  irrespective of a signal from the functional integration VDU  21  or the security-system VDU  22 . In addition, when an OFF signal “ 1 ” of a manual suspension for not suspending the security-system equipment  51  is output from the functional integration VDU  21  or the security-system VDU  22  by an operation of an operator, an OFF signal “ 1 ” is input to the OR circuit  48 , and the OR circuit  48  outputs an automatic suspension OFF signal “ 1 ” for not suspending the security-system equipment  51  irrespective of an OFF signal of an automatic suspension. 
     On the other hand, when the control device does not output an OFF signal of an automatic suspension, an OFF signal “ 0 ” is input to the OR circuit  48 . In addition, when an ON signal of a manual suspension is not output from the functional integration VDU  21  or the security-system VDU  22  without an operation of an operator, an ON signal “ 0 ” is input to the OR circuit  45 . For this reason, the OR circuit  48  does not output an automatic suspension ON signal “ 1 ” for suspending the security-system equipment  51 . 
     Further, when an ON signal “ 1 ” of an automatic suspension is output, the ON signal “ 1 ” is inverted to an ON signal “ 0 ” in the NOT circuit  46 , and is input to the AND circuit  47 . Thus, even when an operator operates the OFF operating switch  34  to output an OFF signal “ 1 ” of a manual suspension, the AND circuit  47  does not output an OFF signal “ 1 ”. That is, when an ON signal “ 1 ” of an automatic suspension is output, processing of an ON signal “ 1 ” of an automatic suspension is given priority over an OFF signal “ 1 ” of a manual suspension from the security-system VDU  31  of the functional integration VDU  21  or the security-system VDU  22 . When an ON signal “ 1 ” of an automatic suspension is not output, an ON signal “ 0 ” is inverted to an ON signal “ 1 ” in the NOT circuit  46 , and is input to the AND circuit  47 . Thus, when an operator operates the OFF operating switch  34  to output an OFF signal “ 1 ” of a manual suspension, the AND circuit  47  may output an OFF signal “ 1 ”. 
     On the other hand, when an OFF signal “ 1 ” of an automatic suspension is output, the OFF signal “ 1 ” is inverted to an ON signal “ 0 ” in the NOT circuit  49 , and is input to the AND circuit  50 . Thus, even when an operator operates the ON operating switch  33  to output an ON signal “ 1 ” of a manual suspension, the AND circuit  47  does not output an ON signal “ 1 ”. That is, when an OFF signal “ 1 ” of an automatic suspension is output, processing of an OFF signal “ 1 ” of an automatic suspension is given priority over an ON signal “ 1 ” of a manual suspension from the security-system VDU  31  of the functional integration VDU  21  or the security-system VDU  22 . When an OFF signal “ 1 ” of an automatic suspension is not output, an OFF signal “ 0 ” is inverted to an ON signal “ 1 ” in the NOT circuit  49 , and is input to the AND circuit  50 . Thus, when an operator operates the ON operating switch  33  to output an ON signal “ 1 ” of a manual suspension, the ON signal “ 1 ” is input to the AND circuit  50  via the OR circuit  11 , and the AND circuit  50  may output an ON signal “ 1 ”. 
     When an operator operates the ON operating switch  35  or the OFF operating switch  36  in the regular-use-system VDU  32  of the functional integration VDU  21 , an ON signal “ 1 ” of a manual suspension or an OFF signal “ 1 ” of a manual suspension is output to the regular-use-system equipment  52 . 
     In the embodiment, as described in the foregoing, the block device includes the AND circuit  41  to which a plant suspension signal (ON signal “ 1 ” of an automatic suspension) output from the security-system VDU  31  of the functional integration VDU  21 , and a block signal (ON signal “ 1 ”) output from the cutoff operating switch  39  of the security-system VDU  22  are input. 
     Herein, a function of the functional integration VDU  21  and the security-system VDU  22  in the device for monitoring an operation of a nuclear plant of the embodiment will be described. 
     Generally, an operator monitors an operation of a nuclear plant using the functional integration VDU  21 . In a case where an abnormality is detected by an operational state of the plant, and a necessary operation is performed in the security-system VDU  31 , when an abnormality is detected in equipment of the security-system equipment  51 , the ON operating switch  33  of the security-system VDU  31  is operated to output an ON signal “ 1 ” of a manual suspension. Then, the ON signal “ 1 ” of a manual suspension output from the ON operating switch  33  is input to the AND circuit  41 . In this instance, since the security-system VDU  31  of the functional integration VDU  21  is being normally operating, the cutoff operating switch  39  of the security-system VDU  22  is not operated, and an ON signal “ 0 ” is inverted in the NOT circuit  43  to be input to the AND circuit  41  as an ON signal “ 1 ”. For this reason, the AND circuit  41  outputs an ON signal “ 1 ”. 
     The OR circuit  44  outputs an ON signal “ 1 ” which is input from the AND circuit  41 . In the AND circuit  50 , since an OFF signal of an automatic suspension is not output, an OFF signal “ 0 ” is inverted to an OFF signal “ 1 ” in the NOT circuit  49  and is input to the AND circuit  50 , the AND circuit  50  outputs an ON signal “ 1 ”, and the ON signal “ 1 ” of a manual suspension is input to the security-system equipment  51  via the OR circuit  45  to safely suspend the security-system equipment  51 . 
     When an operator detects an abnormality in the security-system VDU  31  of the functional integration VDU  21 , the operator disables an operation by the security-system VDU  31 , and performs an operation by the security-system VDU  22 . That is, when an operator detects an abnormality in the security-system VDU  31 , the operator operates the cutoff operating switch  39  of the security-system VDU  22 . Then, an ON signal “ 1 ” is inverted in the NOT circuit  43  to be input to the AND circuit  41  as an ON signal “ 0 ”. For this reason, even when an operator operates the ON operating switch  33  of the security-system VDU  31  to output an ON signal “ 1 ” of a manual suspension, and inputs the ON signal “ 1 ” of a manual suspension to the AND circuit  41 , the AND circuit  41  does not output an ON signal “ 1 ” of a manual suspension since an ON signal “ 0 ” is input from the cutoff operating switch  39  of the security-system VDU  22 . 
     Since the security-system VDU  31  of the functional integration VDU  21  is broken and may not be operated, an operator operates the ON operating switch  37  of the security-system VDU  22  to output an ON signal “ 1 ” of a manual suspension. Then, the ON signal “ 1 ” of a manual suspension output from the ON operating switch  37  is output to the OR circuit  44 , and the ON signal “ 1 ” is output. In the AND circuit  50 , as described in the foregoing, since an OFF signal “ 1 ” of an automatic suspension is input, an ON signal “ 1 ” is output, and the ON signal “ 1 ” of a manual suspension is input to the security-system equipment  31  via the OR circuit  45  to safely suspend the security-system equipment  31 . 
     As described above, in the device for monitoring an operation of a nuclear plant of the embodiment, the functional integration VDU  21  is provided in which the regular-use-system VDU  32  that monitors an operation of the nuclear plant in a normal state and the security-system VDU  31  that suspends the nuclear plant in an abnormal state are included, and the security-system VDU  22  that suspends the nuclear plant in an abnormal state is provided. The functional integration VDU  21  is mounted to the first operating console  12 , and the security-system VDU  22  is mounted to the second operating console  13 . 
     As such, the functional integration VDU  21  including the security-system VDU  31  and the regular-use-system VDU  32  is mounted to the first operating console  12 , and the security-system VDU  22  is mounted to the second operating console  13  and is used as a backup of the security-system VDU  31 . For this reason, only the second operating console  13  may have a structure superior in a seismic resistance, and the first operating console  12  may have a structure having a general seismic resistance. Thus, an increase in size of the first operating console  12  due to seismic strengthening may be suppressed, and an operation may be facilitated. 
     In addition, in the device for monitoring an operation of a nuclear plant of the embodiment, the first operating console  12  is disposed in the center of the central control room  11 , and the second operating console  13  is disposed near a wall surface of the central control room  11  to be adjacent to the first operating console  12 . Accordingly, by appropriately disposing the respective operating consoles  12  and  13 , it is possible to attempt an efficient use of a space within the central control room  11 . 
     That is, by suppressing an increase in size of the first operating console  12 , a disposition of various devices in the central control room  11  may be facilitated, a passage space may be easily ensured, workability may be enhanced, and other devices may be appropriately disposed. 
     In addition, in the device for monitoring an operation of a nuclear plant of the embodiment, the functional integration VDU  21  is provided in which the regular-use-system VDU  32  that monitors an operation of the nuclear plant in a normal state and the security-system VDU  31  that suspends the nuclear plant in an abnormal state are included, and the security-system VDU  22  that suspends the nuclear plant in an abnormal state is provided. The block device is provided to inhibit an operation of the security-system VDU  31  when the functional integration VDU  21  is in an abnormal state. 
     As such, when the functional integration VDU  21  is in a normal state, the security-system VDU  31  of the functional integration VDU  21  is used to safely suspend the nuclear plant in an abnormal state. On the other hand, when the functional integration VDU  21  is in an abnormal state, an operation of the security-system VDU  31  in the functional integration VDU  21  is inhibited by the block device, and the security-system VDU  22  is used to suspend the nuclear plant in an abnormal state. In this case, using the functional integration VDU  21 , the nuclear plant in a normal state may be controlled, and the plant in an abnormal state may be suspended, and thus an operation in the nuclear plant may be facilitated. In addition, when the functional integration VDU  21  is in an abnormal state, an operation of the security-system VDU  31  by the functional integration VDU  21  is inhibited using the block device, and the nuclear plant in an abnormal state is suspended using the security-system VDU  22  functioning as a backup, and thus the plant in an abnormal state may be reliably suspended, and a high security of an operation control may be ensured. 
     In addition, in the device for monitoring an operation of a nuclear plant of the embodiment, the block device is provided in the security-system VDU  22 . Accordingly, it is possible to suspend the nuclear plant in an abnormal state using the security-system VDU  22  immediately after an operation of the security-system VDU  31  in the functional integration VDU  21  is inhibited by the block device. 
     In addition, in the device for monitoring an operation of a nuclear plant of the embodiment, the block device includes the AND circuit  41  to which a plant suspension signal output from the security-system VDU  31  of the functional integration VDU  21  and a block signal output from the security-system VDU  22  are input. Accordingly, when the block device includes a logical circuit, it is possible to simplify the device. 
     In the embodiment described above, a disposition of the first operating console  12 , the second operating console  13 , the operation command console  14 , and the large-size display panel  15  is not limited to the described disposition, and may be appropriately set by an area or a shape of the central control room  11 , and a relation with another device. 
     INDUSTRIAL APPLICABILITY 
     The device for monitoring an operation of a nuclear plant according to the invention suppresses an increase in size of an operating console in the nuclear plant, and may facilitate an operation by providing the first operating console having the regular-use-system control function and the security-system control function, and the second operating console having the security-system control function, and may be applied to any nuclear plant. 
     REFERENCE SIGNS LIST 
       11  CENTRAL CONTROL ROOM 
       12  FIRST OPERATING CONSOLE 
       13  SECOND OPERATING CONSOLE 
       14  OPERATION COMMAND CONSOLE 
       15  LARGE-SIZE DISPLAY PANEL 
       21  FUNCTIONAL INTEGRATION VDU 
       22  SECURITY-SYSTEM VDU 
       31  SECURITY-SYSTEM VDU 
       32  REGULAR-USE-SYSTEM (NON-SECURITY-SYSTEM) VDU 
       39  CUTOFF OPERATING SWITCH (BLOCK DEVICE) 
       41  AND CIRCUIT (BLOCK DEVICE) 
       42  LATCH CIRCUIT (BLOCK DEVICE) 
       43  NOT CIRCUIT (BLOCK DEVICE) 
       44  OR CIRCUIT 
       45  OR CIRCUIT 
       46  NOT CIRCUIT 
       47  AND CIRCUIT 
       48  OR CIRCUIT 
       49  NOT CIRCUIT 
       50  AND CIRCUIT 
       51  SECURITY-SYSTEM EQUIPMENT 
       52  REGULAR-USE-SYSTEM EQUIPMENT