JP3964316B2 - Control device for control rod drive mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a control rod drive mechanism used for inserting or withdrawing a control rod used for controlling the thermal output of a nuclear reactor and shutting down the nuclear reactor.
[0002]
[Prior art]
Conventionally, as a reactor control rod control device of this type, in order to prevent the control rod from dropping when the excitation function of the stationery gripper coil attached outside the reactor pressure vessel is lost in the control rod standby state, Some stationary gripper coils and move valve gripper coils perform selective excitation at the same time to hold a control rod (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Examined Patent Publication No. 4-3517 (page 4)
[0004]
[Problems to be solved by the invention]
However, the conventional control rod drive control logic is realized by a logic circuit using an electronic circuit, and is configured to perform an operation device integrated count of operation commands in units of control rod banks / groups. There is a problem that a deviation from the integrated count with the apparatus occurs, the operation order of the control rod group is reversed, and the step value for starting the bank overlap is shifted. In order to prevent this, there is a problem in that it is necessary to adjust the internal control counter and the integrated count of the external device when the control rod operation is checked and a deviation occurs every time the control rod is operated.
[0005]
The control rod is operated by a lever switch, and the lever switch is set to the stop position when the stop count is reached while monitoring the integrated step value. There is a problem that it is difficult.
[0006]
Also, when checking the function of the control rod drive control logic during periodic inspection, it is necessary to disconnect the external wiring connected to the external device and connect the simulated input device. There are many problems.
[0007]
In addition, there is a problem that a contact failure occurs in the lift coil disconnection switch for selecting and operating an arbitrary control rod, or the control rod does not operate if the operation for restoring it in the disconnected state at the time of inspection is forgotten. is there.
[0008]
Further, when the signal lines of the insertion signal and the extraction signal are short-circuited and both signals are transmitted at the same time, there is a problem that the control rod drive sequence becomes abnormal and the control rod is abnormally operated.
[0009]
The present invention has been made in view of the above-described points, and is intended to obtain a control device for a control rod drive mechanism that centrally manages the operation sequence of the control rod group and the bank selection signal and does not cause a deviation in the operation sequence. Objective.
[0010]
[Means for Solving the Problems]
A control device for a control rod drive mechanism according to the present invention is a control rod drive mechanism used for inserting or withdrawing a control rod used for controlling the thermal output of a nuclear reactor and stopping the nuclear reactor. The control device is provided with a drive order determination logic circuit that determines the drive order of the control rod groups in the same bank based on the operation command integrated count value for each control rod bank group corresponding to the insertion or withdrawal of the control rod. It is what.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. 1 is a circuit diagram showing a control rod drive control logic circuit provided in a control device for a control rod drive mechanism according to Embodiment 1 of the present invention. The logic circuit shown in FIG. 1 is a drive order determination logic circuit that determines the drive order of control rod groups in the same bank based on the operation command integrated count value for each control rod bank group corresponding to insertion or withdrawal of control rods. FIG. 1A shows a case of a two-group configuration, and FIG. 1B shows a case of a three-group configuration.
[0012]
The logic circuit for determining the driving order shown in FIG. 1A shows a difference obtained by subtracting the step count of group 2 from the step count of group 1 given as the operation command integration count value for each control rod bank / group from the host computer. The adder 11 to be obtained, a vise table 21 that outputs a logic level 1 when the output of the adder 11 is 1 or more, and outputs a logic level 0 when the output is less than 1, a NOT circuit 31a-31d, and an AND circuit 41a. -41d and OR circuits 51a and 51b, and the operation order of groups 1 and 2 that determines the drive order of control rod groups in the same bank based on the output of the vise table 21, the individual bank selection signal and the extraction signal from the operator And a logic circuit for outputting bit 3.
[0013]
As an output of the logic circuit, a flag that delays the operation of the group 1 by 1/2 cycle is output as the operation order bit 3 of the group 1, and the operation of the group 2 is 1/2 as the operation order bit 3 of the group 2. A flag to delay the cycle is output.
[0014]
1B includes an adder 11a that obtains a difference obtained by subtracting the group 2 step count from the group 1 step count, and the group 2 step count to the group 3 step. An adder 11b for obtaining a difference obtained by subtracting the count, a vise table 21a that outputs a logic level 1 when the output of the adder 11a is 1 or more, and a device that outputs a logic level 1 when the output of the adder 11b is 1 or more Table 21b, NOT circuits 31a-31g, AND circuits 41a-41l, and OR circuits 51a-51c. Based on the outputs of the vice tables 21a and 21b, individual bank selection signals and withdrawal signals from the operator, The operation order bits 2 and 4 of the group 1-3 for determining the drive order of the control rod group are output. And a logic circuit.
[0015]
As an output of this logic circuit, a flag for delaying the operation of group 1 by 1/3 period is output as the operation order bit 2 of group 1, and the operation of group 1 is set to 2 / A flag for delaying 3 cycles is output, a flag for delaying the operation of group 2 by 1/3 cycle is output as the operation order bit 2 of group 2, and an operation of group 2 is output by 2/3 cycle as the operation order bit 4 of group 2 A flag to delay is output, a flag to delay the operation of group 3 by 1/3 period is output as the operation order bit 2 of group 3, and a flag to delay the operation of group 3 by 2/3 period as the operation order bit 4 of group 3 Is output.
[0016]
Therefore, according to the first embodiment, in order to determine the period for delaying the operation of each group based on the relationship between the difference between the step count groups and the extraction signal, in the case of the two-group configuration shown in FIG. It is assured that the operation is shifted by a half cycle in the order of groups 1 and 2 when inserted, and in the order of groups 2 and 1 when inserted. In addition, in the three-group configuration shown in FIG. 1 (b), the operation is shifted by 1/3 period in the order of groups 1, 2, and 3 when pulled out, and in the order of groups 3, 2, and 1 when inserted. Is definitely guaranteed.
[0017]
That is, according to the first embodiment, since the operation order of the control rod group and the bank selection signal are centrally managed by the integrated count value of the control rod in bank group units, there is no deviation in the operation order. The necessary internal control count and external step integrated value adjustment are no longer required.
[0018]
Embodiment 2. FIG.
2 is a circuit diagram showing a control rod drive control logic circuit provided in a control device for a control rod drive mechanism according to Embodiment 2 of the present invention. The control rod drive control logic circuit shown in FIG. 2 shows a bank selection signal generation logic circuit that generates a bank selection signal at the time of overlap operation based on the operation command integration count value of the control rod bank / group unit. -12j, vice tables 22a-22m, NOT circuits 32a-321, AND circuits 42a-421, and OR circuits 52a-52e.
[0019]
This logic circuit includes an individual bank selection signal, a power cabinet emergency alarm, a withdrawal signal, a group 3 CBA (control bank A) step count and set value S2, and a group 1 CBB (control bank B) step count and set value. (S2-S1), set value S1, group 3 CBB (control bank B) step count and set value S4, group 1 CBC (control bank C) step count, set value (S2-S1), set value S3, group 3 CBC (control bank C) step count and set value S6, group 1 CBD (control bank D) step count and set value (S6-S5), group 1 CBC (control bank C) Step count, group 3 CBC (control bank C) step count and set value S5, and group 1 CB (Control Bank C) CA (Control Bank A) selection signal, CB (Control Bank B) selection signal, CC (Control Bank C) selection signal and CD (Control Bank) based on step count and set value S5 D) Output a selection signal.
[0020]
Here, the set value S2 is the upper limit value of the withdrawal step count of the control bank A, and the set value (S2-S1) is the CBB (control bank B) step count of the group 1 and the control bank A at the time of insertion. This is the start setting step count value that overlaps with the control bank B, and the other setting values are the same except that the target bank is different.
[0021]
Therefore, according to the second embodiment, since the bank selection signal is generated from the bank group step count, it is guaranteed that the bank selection signal is generated according to the set bank overlap sequence. No need to check or adjust the time.
[0022]
Embodiment 3 FIG.
3 is a circuit diagram showing a control rod drive control logic circuit provided in a control device for a control rod drive mechanism according to Embodiment 3 of the present invention. The control logic circuit shown in FIG. 3 shows a latch signal logic circuit that outputs an insertion or extraction latch signal for operating the control rod up to the required number of operation steps, and FIGS. 3A and 3B show the extraction operation. FIG. 3C and FIG. 3D show circuit diagrams during the insertion operation. The circuit shown in FIG. 3A includes switches 63a to 63h, and outputs a step count current value 1 as a result of selecting a step count at the time of pulling operation based on a bank selection signal.
[0023]
Here, the SBA selection signal indicates that the stop bank A is selected, the SBB selection signal indicates that the stop bank B is selected, and the SBC selection signal selects the stop bank C. The SBD selection signal is a signal indicating that the stop bank D is selected, the CBA selection signal is a signal indicating that the control bank A is selected, and the CBB selection signal is the control bank A signal indicating that B is selected, a CBC selection signal is a signal indicating that the control bank C is selected, and a CBD selection signal is a signal indicating that the control bank D is selected. . Also, the SBA step count is the stop bank A step count, the SBB step count is the stop bank B step count, the SBC step count is the stop bank C step count, the SBD step count is the stop bank D step count, The CBA step count is the control bank A step count, the CBB step count is the control bank B step count, the CBC step count is the control bank C step count, and the CBD step count is the control bank D step count. Yes.
[0024]
Further, the circuit shown in FIG. 3B has an operator manual pull-out signal, a step count current value 1 as an output from the circuit shown in FIG. 3A, and an operation request step number as a target value of the number of pull-out steps. 3 shows a circuit for outputting a pull-out latch signal based on this, and when the manual pull-out signal of the operator becomes 1, the signal is stored in the flip-flop 83a, and a pull-out latch signal is generated. When the extraction latch signal becomes 1, a numerical value obtained by adding the operation request step number to the step count current value 1 by the adder 13a is input to the signal selector 73a and held. The step count current value 1 is added together with the extraction, and the difference from the number of steps held is obtained by the adder 13b. When the difference becomes Q, the vise table 23a becomes 1 and the flip-flop 83a is reset and the extraction is performed. The latch signal is released. Note that the circuits shown in FIGS. 3C and 3D correspond to the insertion operation, and the operation is the same as described above.
[0025]
Therefore, according to the third embodiment, since the operation command signal is latched and latched up to the number of operation requests, the operation can be reliably performed by the number of steps desired by the operator, and the operability is improved.
[0026]
That is, since it is possible to input the operation step request value, it is possible to operate as many steps as desired, so that the operability is improved and the time required for the control rod operation can be shortened.
[0027]
Embodiment 4 FIG.
4 is a circuit diagram showing a control rod drive control logic circuit provided in a control device for a control rod drive mechanism according to Embodiment 4 of the present invention. The control logic circuit shown in FIG. 4 is shown corresponding to the logic circuit according to the third embodiment shown in FIG. 3, and as shown in FIGS. 4B and 4D, a signal selector 73a and an adder are provided. 13b, an upper limiter 94a is provided between the signal selector 73a and the adder 13d, and a lower limiter 94b is further provided between the signal selector 73a and the adder 13d. The latch signal logic circuit is configured such that the operation is prohibited when the upper limit is reached.
[0028]
Therefore, according to the fourth embodiment, since the control rod is not overdrawn and over-inserted, the operation reliability of the control rod drive mechanism is improved.
[0029]
Embodiment 5 FIG.
FIG. 5 is a view showing a maintenance operation tool provided in a control device for a control rod drive mechanism according to Embodiment 5 of the present invention. The maintenance operation tool 100 shown in FIG. 5 has a display unit 100a for displaying the operation command integrated count value in units of control rod banks and groups in the bank selection signal generating logic circuit in the second embodiment shown in FIG. The bar operation and various parameters are set. A screen 100b is displayed on the display unit 100a so that various setting values can be input.
[0030]
Therefore, according to the fifth embodiment, since the set value can be input visually, a human error at the time of setting can be prevented. By installing the maintenance setting tool permanently, it is not necessary to attach or remove the simulated operation panel during inspection, reducing the amount of work during inspection.
[0031]
Embodiment 6 FIG.
FIG. 6 is a diagram illustrating a reverse instruction prohibiting circuit provided in the control device for a control rod drive mechanism according to Embodiment 6 of the present invention. 6 shows a logic circuit that prohibits the pull-out command when the control rod insertion command is transmitted and prohibits the insert command when the pull-out command is transmitted. The NOT circuit 16a-16e and the AND circuit 46a- 46h and OR circuits 56a-56C, and manual and automatic operation signal OR and bank selection signal, the inverted signal of the final stage insertion signal (output of AND circuit 46g) gated by the alarm signal, as the extraction signal, Further, the inverted signal of the final stage extraction signal (output of the AND circuit 46h) is used as an insertion signal so as to pass through the AND gates 46i and 46j.
[0032]
Therefore, according to the sixth embodiment, since the insertion signal and the extraction signal are not generated simultaneously, the operation reliability of the control rod is improved. In addition, since the insertion / extraction signal is prohibited at the insertion limit and the extraction limit, it is possible to prevent over-insertion / extraction of the control rod, thereby contributing to the improvement of the operation reliability of the control rod drive mechanism.
[0033]
Embodiment 7 FIG.
FIG. 7 is a diagram showing a notification circuit provided in a control device for a control rod drive mechanism according to Embodiment 7 of the present invention. This notification circuit includes an OR circuit 57a, and issues an alarm when one lift disconnect switch is disconnected based on the logical sum of all lift disconnect switches for disconnecting the energization circuit of the lift coil. ing.
[0034]
Therefore, according to the seventh embodiment, since the state of the lift disconnect switch is constantly monitored, the failure rate at which the control rod does not operate is reduced, and the control rod operation reliability is improved. In addition, since the lift coil disconnection switch is diagnosed, it is possible to detect contact failure at an early stage and prevent recovery from being forgotten at the time of inspection, thereby contributing to improvement in operation reliability.
[0035]
【The invention's effect】
As described above, according to the present invention, the operation order of the control rod group and the bank selection signal are centrally managed by the integrated count value of the bank group unit of the control rod. The necessary internal control count and external step integrated value adjustment are no longer required.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of the present invention.
FIG. 2 is a diagram showing a second embodiment of the present invention.
FIG. 3 is a diagram showing a third embodiment of the present invention.
FIG. 4 is a diagram showing a fourth embodiment of the present invention.
FIG. 5 is a diagram showing a fifth embodiment of the present invention.
FIG. 6 is a diagram showing a sixth embodiment of the present invention.
FIG. 7 is a diagram showing Embodiment 7 of the present invention.
[Explanation of symbols]
11, 11a, 11b, 12a-12j, 13a-13d, 16a-16e Adder, 21, 21a, 21b, 22a-22m, 23a-23b Vise table, 31a-31g, 32a-32l NOT circuit, 41a-41l, 42a-421, 46a-46j AND circuit, 51a-51c, 52a-52e, 56a-56c, 57a OR circuit, 63a-63p switch, 73a-73b signal selector, 83a-73b flip-flop, 94a upper limiter, 94b lower limit Limiter, 100 maintenance operation tool, 100a display unit, 100b screen.

Claims (7)

In a control device for a control rod drive mechanism used to insert or withdraw a control rod used for controlling the thermal output of the reactor and shutting down the reactor,
A control rod comprising a drive sequence determination logic circuit that determines the drive sequence of control rod groups in the same bank based on an operation command integrated count value for each control rod bank group corresponding to insertion or withdrawal of the control rod Control device for drive mechanism. The control device for a control rod drive mechanism according to claim 1,
A control device for a control rod drive mechanism, comprising a bank selection signal generation logic circuit for generating a bank selection signal at the time of an overlap operation based on an operation command integrated count value in units of control rod banks and groups. The control device for a control rod drive mechanism according to claim 1 or 2,
A control device for a control rod drive mechanism, comprising a latch signal logic circuit for outputting an insertion or extraction latch signal for operating a control rod up to a required value for the number of operation steps. The control device for a control rod drive mechanism according to claim 3,
The control circuit for the control rod drive mechanism, wherein the latch signal logic circuit prohibits the operation when reaching the control rod insertion lower limit or the extraction upper limit based on the operation command integrated count value of the control rod bank group unit . The control device for a control rod drive mechanism according to claim 2,
It has a display unit for displaying an operation command integrated count value for each control rod bank / group in the bank selection signal generation logic circuit, and has a maintenance setting tool for setting control rods and various parameters. A control device for a control rod drive mechanism. The control device for a control rod drive mechanism according to any one of claims 1 to 5,
A control device for a control rod drive mechanism, comprising: a reverse instruction prohibiting circuit that prohibits a withdrawal command when a control rod insertion command is transmitted and prohibits an insertion command when a withdrawal command is transmitted. The control device for a control rod drive mechanism according to any one of claims 1 to 6,
A control rod drive mechanism characterized by comprising a notification circuit for notifying when even one lift disconnect switch is disconnected based on the logical sum of all lift disconnect switches for disconnecting the energization circuit of the lift coil. Control device.

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