JP2703972B2 - Control rod and fuel monitoring and control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) Control rods of a nuclear reactor for safely performing fuel exchange and control rod operation when replacing fuel and control rods in a nuclear power plant. And a fuel monitoring and control device.

(Prior Art) In a nuclear power plant, fuel and control rods in a furnace are exchanged during a periodic inspection (hereinafter abbreviated as a regular inspection). At this time, in order to maintain the safety of the operation and the reactor, at the time of fuel loading and control rod removal, one or more control rods were conventionally pulled out of the refueling machine control unit in order to prevent unnecessary reactor reactions. In the case of a refueling prevention interlock to prevent fuel from moving on the reactor core, the reactor mode switch is set to the "refueling mode" for the control rod operation monitoring device. When in the state, the control rod withdrawal interlock of "cannot pull out more than 2 control rods" is provided,
According to these interlocks, the refueling work at the time of regular inspection was performed safely. That is, in the fuel loading operation, the refueling machine does not operate unless all the control rods are fully inserted, and once the reactor mode switch is set to the "fuel replacement mode", the fuel cell to be loaded with the fuel is to be loaded. , Except for one control rod. However, this fuel loading operation was carried out under the oversight of the monitoring personnel, but no other special interlock was provided.

(Problems to be solved by the invention) At the time of regular inspection, replacement or position change of 100 or more fuels is performed, and control rods are also 20 to 50 times.
The book is overhauled or replaced. When these operations are performed according to the conventional interlock, only one control rod can be pulled out at any one time, which increases the operation time,
There was a problem that it took an extremely long time for regular inspection. In addition, fuel replacement work is performed under the sufficient management of the operator. However, if fuel is loaded into a fuel cell (area) where the control rods are not fully inserted due to erroneous operation or misjudgment, Can also assume a problem that the reactivity in this region becomes high.

The present invention has been made in view of the above, and has as its object the control rod position information from the control rod operation monitoring device, the fuel state information from the refueling exchange control device, and the state of the reactor mode switch. And neutron flux information from the start-up area monitor to automatically and safely and efficiently perform fuel, control rod replacement and control rod operation work, and control with an interlock that can reduce the period of regular inspection It is an object of the present invention to provide a rod and fuel monitoring control device.

[Structure of the Invention] (Means for solving the problems) For the control operation monitoring device and the fuel exchange control device, the neutron flux information and the control rod position information from the reactor operation mode switch status information and the start-up area monitor are provided. An input processing circuit for input processing of fuel status information and the like, a control rod position storage circuit for control rod position information, a fuel status storage circuit for fuel status information, and operation of the refueling machine from the control rod position based on such information. , A control rod operation monitoring circuit for monitoring the control rod operation from information from the state of the fuel, the state of the reactor mode switch, and the start area monitor, and the like, and the refueling machine operation monitoring circuit and control. An output circuit for inputting a signal from the rod operation monitoring circuit and outputting a signal such as operation inhibition to the control rod operation monitoring device and the fuel exchange control device; Comprising a display device for displaying.

(Operation) The control rod operation monitoring device and the refueling machine control device perform the operation of fuel exchange and control rod operation completely and efficiently by the mutual operation by the following monitoring interlock.

First, for the control rod operation monitoring device: (1) If the refueling machine is on the reactor core and is in a fuel-loaded state, prevent the control rod from being pulled out.

(2) When the reactor operation mode switch is in the "fuel exchange mode" and fuel is present in the fuel cell, the control rod is prevented from being pulled out.

(3) When the neutron flux level in the start-up area monitor is higher or lower than the set value, pull out of the control rod is prevented.

(4) Unless the fuel cell contains no fuel and the fuel support is inserted, the control rod is prevented from being pulled out.

(5) If the control rod / fuel monitoring control unit is out of order, prevent the control rod from being pulled out.

Next, for the refueling control system: (6) The reactor operation mode switch is in the "fuel changing mode", and while one control rod is being pulled out, the movement of the refueling machine is prevented.

(7) Fuel loading is stopped during control rod operation.

(8) If the control rod of the fuel cell is not at the full insertion position, stop loading the fuel.

(9) When the neutron flux level in the start area monitor is higher / lower than the set value, fuel loading is stopped.

(10) When there is no command signal from the control rod monitoring system, fuel loading is stopped.

(11) If the control rod / fuel monitoring control unit is out of order, stop fuel loading.

Example An example of the present invention will be described with reference to the drawings. FIG. 1 is an overall block diagram showing a control rod / fuel monitoring control device 1.
And the control rod operation monitoring device 40 and the fuel exchanger control device 50. The control rod / fuel monitoring and control device 1 of the present invention inputs the status information of the reactor mode switch 60, the neutron flux information from the start-up area monitor 61, and the information from the control rod operation monitoring device 40 and the fuel exchange control device 50 and the like. Input processing circuit 2 for processing
And a fuel status storage circuit 3 and a control rod operation monitoring circuit 4 for sequentially storing status information of the fuel, and a control rod position storage circuit 5 and a refueling machine operation monitoring circuit 6 for storing control rod position information. And an output circuit 7 for receiving the outputs of the refueling machine operation monitoring circuit 6 and the control rod operation monitoring circuit 4 and outputting a blocking signal to the control rod operation monitoring device 40 and the refueling machine control device 50. CR to display
It comprises a display device 8 made of T or the like.

The configuration of the control rod operation monitoring device 40 is, as shown in FIG.
2, a control rod control unit comprising a control rod control circuit 43 and an electromagnetic valve drive circuit 44 for controlling an electromagnetic valve 48 for driving a control rod (not shown), and input control rod position information from a control rod position sensor 49. A position detection circuit 45 for detecting the position of the control rod, a state processing circuit 46, and an output display device 47 are connected to the control rod operation panel 41.
And a control rod monitoring unit sequentially connected to the control rod monitoring unit.

Further, the refueling control device 50 includes a control logic unit 52 sequentially connected to the refueling operation console 51, a Leonard control unit 53 for outputting a signal for driving a mast motor 56 of the refueling machine (not shown), and a fuel position sensor of the refueling machine. A fuel position detection circuit 54 and a transmission circuit 55 for inputting fuel position information from 57 are sequentially connected to the control logic unit 52.

In the control rod / fuel monitoring control device 1, information is input from the reactor mode switch 60 and the starting area monitor 61, and information is exchanged between the control rod operation monitoring device 40 and the fuel exchange control device 50. From the control rod operation monitoring device 40, the position of the control rod is received by the position detection circuit 45 as an output of the control rod position sensor 49 and displayed on the control rod operation panel 41, and the output control rod position indication signal S45 is output. The control rod position storage circuit 5 stores the position state of each control rod. The state of the control rod is indicated by the control rod number indicated by coordinates (XY) and the insertion position (notch position), and when displayed on the display device 8, the control rod number is designated by coordinates. You can check it. The information of the control rod position storage circuit 5 and the reactor mode switch
The refueling machine operation monitoring circuit 6, which inputs the state of 60, the neutron flux information of the start-up area monitor 61 and the control rod operation signal S42 output from the control rod selection circuit 42 of the control rod operation monitoring device 40, etc. A surveillance interlock has been built to enable refueling.

As shown in the logic configuration diagram of FIG. 2, this refueling machine operation monitoring circuit 6 has one AND circuit 10 and one NOT circuit 11
The monitoring interlock is provided when the state of the reactor mode switch 60 is “refueling mode 20” and “during control rod withdrawal operation 21”.
It outputs the "rechanger movement inhibition 22" signal. They are trying to load more fuel. “When the control rod of the fuel cell is not in the fully inserted state 23”, or when the signal of “the activation area monitor level is higher / lower than the set value 24”, or when “the control rod is operating 25”, or “No control rod position signal 2
In the case of "6" or "the control rod / fuel monitoring / control device has a failure 27", a "fuel loading prevention 28" signal is output.

The signals from the refueling machine operation monitoring circuit 6 for the refueling machine movement prevention 22 and the fuel loading prevention 28 are adjusted to an appropriate signal level in the output circuit 7, and are controlled as a blocking signal S7a by the control logic unit of the refueling machine controller 50. Entered in 52.

On the other hand, the position information of the fuel in the core is input to the fuel position detection circuit 54 of the refueling machine control device 50 from the fuel position sensor 57 of the mast of the refueling machine holding the fuel, and is transmitted as a signal S55 through the transmission circuit 55 to the present invention. Is input to the input processing circuit 2 of the control rod / fuel monitoring and control device 1. Similarly, the position setting signal of the exchanged fuel at the refueling machine console 51 is also input to the input processing circuit 2 and stored in the fuel state storage circuit 3 together with the fuel state information. Further, the position information of the fuel support temporarily inserted instead of the fuel is also stored separately from the fuel. That is, the fuel and the fuel support are also indicated by the address of the core and the presence or absence of the fuel number or fuel support number loaded at that position. The state of the fuel and the fuel support can be easily confirmed by the display device 8. A control rod for inputting information of the fuel state storage circuit 3, the state of the reactor mode switch 60, the neutron flux from the start-up area monitor 61, and the fuel gripping state (weighted state) from the fuel exchanger control device 50, etc. The operation monitoring circuit 4 is provided with a monitoring interlock capable of safely operating the control rod.

This control rod operation monitoring circuit 4 has three AND circuits 13, 14, 15 and one NOT circuit as shown in the logic configuration diagram of FIG.
16 and OR circuit 17, and this monitoring interlock is
“The refueling machine is on the core 30” and “fuel-weighted
31 "or the reactor mode switch 60 is in the" fuel change mode 32 "and" there is fuel in the fuel cell 32 "
Or when the signal of “neutron flux level is higher / lower than set value 34” in the activation area monitor or “No fuel is present in the fuel cell (of the control rod to be withdrawn) 3
Other than 5 "and" 36 with fuel support ", or the" control rod / fuel monitoring and control device outputs a signal of "control rod removal prevention 38" by a signal of failure 37 ".
Signals of "there is fuel in the fuel cell 33", "there is no fuel in the fuel cell 35" and "there is fuel support 36" are output from the fuel state storage circuit 3.

Also, control rod withdrawal from the control rod operation monitoring circuit 4 is prevented.
The signal 38 is converted to an appropriate signal level in the output circuit 7, and is input to the control rod control circuit 43 of the control rod operation monitoring device 40 as a signal S7b.

Next, the operation of the above configuration will be described. The state information of the reactor mode switch 60 and the neutron flux information of the activation area monitor 61 are input to the input processing circuit 2. The control rod position information is input from the control rod position sensor 49 to the position detection circuit 45 of the control rod operation monitoring device 40, and is input as a signal S45 to the input processing circuit 2 of the control rod / fuel monitoring and control device 1. The control rod position storage circuit 5 stores the position states of all the control rods. Further, the arrangement information of the fuel and the fuel support in the core is input from the fuel position sensor 57 of the refueling machine to the fuel position detecting furnace 54 of the refueling machine control device 50, and is transmitted as a signal S55 through a transmission circuit 55 to the control rod / fuel support. The data is input to the input processing circuit 2 of the monitoring control device 1 and stored in the fuel state storage circuit 3. This information is updated with new data as needed each time the control rod is operated or refueled, together with the information stored in the control rod position storage circuit 5.

During the fuel loading operation, first, the position of the fuel to be loaded is designated on the refueling machine console 51. The control rod / fuel monitoring and control device 1 which has received the designated position signal checks the status of the control rods of the fuel cell corresponding to the fuel loading position from the control rod position storage circuit 5 and sends it to the refueling machine operation monitoring circuit 6. hand,
It is determined based on the information on the start area monitor 61 and the operation state of the control rods whether or not the refueling machine can be operated. Here, under the condition that the monitoring interlock of the refueling machine operation monitoring circuit 6 is violated, a signal of the refueling machine movement prevention 22 or the fuel loading prevention 28 is output, and the operation is prohibited in the control logic unit 52 of the refueling machine control device 50. Made, Leonard control circuit
Via 53, the operation of the mast motor 56 of the refueling machine is blocked.

During the fuel removal operation from the core to the fuel pool, the same monitoring as described above is performed by the refueling machine operation monitoring circuit 6, but the movement of the refueling machine is prevented while the control rod is being pulled out.
Except for the signal 22, the work is possible and the fuel removal work can be continued.

At the time of control rod withdrawal, the control rod operation panel 41 of the control rod operation monitoring device 40 selects the target control rod and starts the withdrawal operation.
The selection signal S42 is output from the selection circuit 42 to the input processing circuit 2 of the control rod / fuel monitoring and control device 1. The state of fuel in the selected fuel cell is checked from the fuel state storage circuit 3, and the control rod operation monitoring circuit 4 checks the position of the refueling machine and the weight of fuel, the presence / absence of fuel support insertion, and information on the start area monitor 61. It is determined whether the control rod pull-out operation is possible. Under the condition in which the monitoring interlock of the control rod operation monitoring circuit 4 is violated, the signal of the control rod pullout prevention 38 is output from the output circuit 7 as the signal S7b to the control rod control circuit 43 of the control rod operation monitoring device 40, and the solenoid valve is driven. The control rod withdrawal operation is prevented via the circuit 44 and the control rod driven control solenoid valve 48.

If the inhibition condition of the control rod operation monitoring circuit 4 is not satisfied, for example, if all four fuel cells of the fuel cell to which the control rod belongs have been removed, the control rod will react with other surrounding fuel. Since it does not affect the degree, the control rods can be continuously pulled out, and a plurality of control rods can be pulled out.

In the display device 8 of the control rod / fuel monitoring control device 1, when replacing fuel and control rods and operating the control rods,
It is also possible to confirm in advance a situation where the monitoring interlock of the refueling machine operation monitoring circuit 6 and the control rod operation monitoring circuit 4 does not conflict.

[Effects of the Invention] As described above, according to the present invention, in a conventional nuclear power plant, when one or more control rods are pulled out, fuel cannot move on the reactor core, and when the fuel is replaced, the control rods cannot be moved. Since it was not possible to pull out more than two of them, it took a long period of time to perform refueling and control rod inspections, etc., which were carried out during the periodic inspection, which required an extremely long period of periodic inspection. The fuel can be moved even when the control rod is pulled out after securing the control rod, and since multiple control rods can be pulled out, safe and efficient work can be performed automatically and extremely greatly. There is a beneficial effect that the period of the periodic inspection can be shortened.

Also, since the fuel loading work management is performed without human management, there is no need to worry about problems such as a partial increase in reactivity from fuel loading due to erroneous operation or misjudgment. It also has the effect of reducing the burden.

[Brief description of the drawings]

FIG. 1 is an overall block diagram of an embodiment of the present invention, FIG. 2 is a logic diagram of a refueling machine operation monitoring circuit, and FIG. 3 is a logic diagram of a control rod operation monitoring circuit. 1 ... control rod / fuel monitoring control device 2 ... input circuit 3
…… Fuel state storage circuit, 4 …… Control rod operation monitoring circuit, 5
... control rod position storage circuit, 6 ... refueling machine operation monitoring circuit, 7 ... output circuit, 8 ... display device,
… AND circuit, 11,16 …… NOT circuit, 12,17 …… OR circuit, 40…
... Control rod operation monitoring device, 50 ... Fuel exchange control device, 60
…… Reactor mode switch, 61 …… Start area monitor.

Claims (1)

(57) [Claims] 1. A monitoring and control device for control rod operation and refueling in a nuclear reactor of a nuclear power plant, comprising: a neutron flux information from a mode switch state of a reactor operation, a start area monitor, and a control rod operation monitoring device. An input processing circuit for input processing of the control rod position information and the fuel state information from the fuel exchanger control device; a control rod position storage circuit for inputting and storing the control rod position information; and inputting the fuel state information. A fuel status storage circuit for storing and storing, a fuel exchanger operation monitoring circuit for monitoring the operation of the fuel exchanger from the control rod position based on the control rod position information and the fuel status information, a fuel status and a reactor mode switch status And a control rod operation monitoring circuit for monitoring the control rod operation based on information from the start area monitor, and signals from the refueling machine operation monitoring circuit and the control rod operation monitoring circuit. And an output circuit for outputting an operation inhibition signal to the control rod operation monitoring device and the refueling machine control device; and a display device for displaying the status of the control rod and fuel. apparatus.