JPS5999294A - Control device of reactor control rod - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nuclear reactor control rod control device, and in particular, to a control rod control device used for controlling thermal output of a nuclear reactor and shutting down a nuclear reactor.
The present invention relates to a control device for a control rod drive mechanism used for insertion into or withdrawal from a nuclear reactor.

FIG. 1 shows a simplified structure of a magnetic jack type drive mechanism for nuclear reactor control rods. In the figure, three coils, lift coil/, movable gripper coil (hereinafter referred to as MG coil) 2, and stationary gripper coil (hereinafter referred to as SG coil) 3, installed outside the reactor pressure vessel are connected to the reactor pressure vessel. Operates the excitation contact piece housed inside. That is, the movab/I/ clipper armature and the stationary gripper armature actuate the latches 7 and g that engage with the groove 6a of the control rod drive mechanism when the MG coil coil 3 and the sG coil 3 are energized, respectively. The stationary latch is used to hold the control rod drive shaft 6 in a certain position. The movable latch 7 is raised and lowered by the lift armature when the lift coil l is excited, and raises the control rod drive shaft 6 (moves in the withdrawal direction) and lowers it (moves in the insertion direction). used for.

In addition, /a is the lift magnetic pole, 3ε is the stationary gripper magnetic pole, S is the stationary gripper armature, ta
Has a movable latch link,! ra is a stationary latch link.

Figure 1 shows the operation sequence of the control rod drive mechanism. In FIG. 2, corresponding parts in FIG. 1 are represented by the same reference numerals, but the movable latch 7 and the stationary latch g are shown in a simplified manner.

The control rod withdrawal sequence and insertion sequence will be described below with reference to FIGS. 1 and 2.

A: Pulling sequence (a) In the standby state, the SG coil 3 is energized and the SG coil 3 is
Notation latch g is closed and retains the control rod drive shaft. [Status shown in Figure 2 (a)-(b)] (b)
The movable latch 7 is closed by exciting the MG coil λ.

[State shown in Figure 2 (a)-middle)] (c) Demagnetize the S() coil 3 and release the stationary latch t. [
1) Excite the lift coil 1 to operate the lift armature t and raise the movable gripper armature. Is this a movable latch? The control rod drive shaft 6 supported by the control rod drive shaft is raised in the direction of the arrow by one groove 6a of the control rod drive shaft.

[Figure 2 ((Support) - (-!I state)] (E) Excite the SG coil 3 and stationary latch t
Close [Figure 2 (a) - (@ state] (to) MG
Demagnetize the coil and release the movable latch. [
Conditions in Figure 1 (a)-(f)] (g) Demagnetize the lift coil and lower the lift armature 9 in the direction of the arrow. [Status in Figure 2 (a)-(G)] (E) Repeat operations from (B) to (G).

(d) B: Insertion sequence (a) In the standby state, the SG coil 3 is excited, the stationary latch g is closed, and the control rod drive shaft 6 is held. [States shown in Fig. 2 (b) - (a)] (middle) Excite the lift coil / to raise the lift armature in the direction of the arrow. [State shown in Figure 1 (b)-middle)] (c) Excite the MG coil coil and close the movable latch. [In the state of Figure 2 (b)-(c)]) SG
Demagnetize the coil 3 and release the stationary latch g. [Status shown in Figure 2 (bl-)] (e) IJ 7
): Demagnetize the ff file, lower the lift door 9, and lower the mover pull gripper qf. The control rod drive shaft 6 is now lowered in the direction of the arrow by seven grooves 6a.

[Figure 2(b) - (state of J-1] (to) Excite the 8G coil 3 and close the stationary latch t.

[Status of Figure 1 (b)-(f)] (g) MG coil λ
Demagnetize and release the mover full clipper.

[Status shown in Figure 1 (b) - ()] From (a) (b) to (
Repeat the steps in step (g).

As mentioned above, the operation of inserting or withdrawing a control rod into a nuclear reactor is performed by sequentially supplying direct current to three types of coils, the SG coil, MG coil, and lift coil of the control rod drive mechanism. When the control rod is not driven, it is held at a constant position by continuing to excite the SG coil. Here, when the control rod is not driven (Fig. 2 (
It is important to note that in al and (b)-(a)), if the SG coil is not energized, the control rod will fall into the reactor.

The control rod controller supplies direct current to the three types of coils in the control rod drive mechanism. Conventionally, there has been a device of this type as shown in FIG. In the figure, loads IO1, 20, and 3θ correspond to the three types of coils of the control rod drive mechanism described above, respectively. That is, the load IO corresponds to the S( ) coils of the plurality of control rod drive mechanisms, and the load IO
corresponds to the MG coil of a plurality of control rod drive mechanisms, and the load 30 corresponds to a lift coil of a plurality of control rod drive mechanisms (
7) Do. Each load consists of three groups of loads. That is, the load IO of the first set is S of the first group/2, the second group/l, and the third group/6.
Consists of G coil. These three groups of /2°/g and /6 loads all require a DC sequence at the same level (when exciting the SG coil to hold the control rods), and the control rods are driven sequentially by group, but the control In order to hold the control rods in a fixed position even when the rods are not driven, it is necessary to energize the SG coils of all control rod drive mechanisms,
The switching operation is not performed like the loads of the first set and the third set.

Similarly, for the second set of loads CoO, the first group Coco, the first group λq1
and the third group consists of two MG coils.

The loads in each of these three groups all still require the same level of DC sequence, but with different excitation periods.

That is, all three groups of control rods are driven, but their driving times are different. Accordingly, the first group of control rods is driven by a first group of control rod drive mechanisms comprising a first group of SG coils, a first group of MO coils, and a first group of lift coils. The first group of control rods is driven by a first group of control rod drive mechanisms including a second group of SG coils, MG coils, and lift coils. Similarly, the third group control rods are driven by a third group control rod drive mechanism.

As described above, the drive sequence for each group of control rods is performed by sequentially energizing the three types of coils of each control rod drive mechanism.

The three-phase power is supplied to multiple electrical units l12. by the three-phase power supply qo. 'It...! ; is supplied to θ, 52 and tl. This electric kaninit supplies DC output at predetermined multi-level (usually three levels) values based on a reference current signal from a reference current source, which will be described later. The first electric power supply 9.2 is connected to a three-phase power supply 1.2 through a line illustrated as a single line tat.
Receives three-phase power from 10. The first power unit 2 is an electric power unit for providing a DC sequence to the lift coils of a plurality of control rod drive mechanisms. Three phase power supply lIo
A second output from is supplied to the first electrical circuit 96 through line qt. The first power unit 2 is an electric power unit for providing DC current to the MG coils of the plurality of control rod drive mechanisms. The lines st, s'g: and 6θ are connected from the third output group 9 from the three-phase power supply source 6, respectively.
Three separate electric crab knits each through! ;0. !
;3-phase power is supplied to 2 and 51.

Electric crab units so, tacho, and 1+ are electric crab units for providing direct current to the S( ) coils of a plurality of control rod drive mechanisms in a predetermined sequence, respectively.

Each load/,2. Separate electric crab knit go, ra and! The reason for providing r+ is that when a group of control rods is inserted or withdrawn during operation of the control rod drive device, the SG coils of the control rod drive mechanisms of the remaining control rod groups are energized to control these control rods. This is because it is necessary to hold the rod in a fixed position. For example, if the first group of control rod drives is to be energized, i.e., the first group I
The first group load (SG coil) 12 of O, the first group load (MG coil) 22 of second group θ, and the first group load (lift coil) 32 of third group 30 are connected to a predetermined DC sequence. When energizing sequentially according to This is because it is necessary to prevent it from falling.

6.2 is typically divided into three levels: zero current value (current value when the coil is demagnetized), low current value (current value required to hold the control rod), and full current value (current value when the control rod is initially This is a well-known reference current source that generates in a predetermined sequence a reference current signal having a current value required only for driving. Direct current is supplied to the load.The reference current source 6 supplies a seventh reference current signal to the first electric cylinder unit q2 through a line 1.4'.The first electric cylinder unit q2, that is, the lift coil of the control rod drive mechanism A first reference current signal is used to adjust the DC output from the first electric unit or the first, first, and third group loads 32. .3q and 36 via lines tg, go and g2, respectively, the output from the first power unit dco is connected to a first switch/tt1 switching circuit 66 (e.g. external bank selection (controlled by the circuit).

Similarly, a second reference current signal from the reference current sources 6 is supplied via a line to a second electric crab unit 116, which is an electric crab unit for MG coils of a plurality of control rod drive mechanisms. The DC output from this first power unit is supplied to the second switching circuit 76, and the loads 22 of the first, second, and third groups are
．． Track AI to any seven of 2'l and 2o.

70 and? DC is supplied through the

The reference current source 62 supplies three separate groups of third reference current signals via lines gp, gt, and trg to the 3″ fL crab knits 5θ, 52, and 5, which are type crab knits for SC) coils, respectively. (All groups are supplied with reference current signals of the same DC level in the holding state.) A separate third reference current signal group is supplied to these three electrical units.

The reason is that when the second group of control rods is inserted or withdrawn, it is necessary to energize the SO coils of the control rod drive mechanisms of the remaining control rod groups to hold these control rods in a fixed position. It is. Note that the first and third electric capacitors may be configured as thyrisk type converters, and the seventh and second
The switching circuit may also be constructed as a silicate switching device.

Since the conventional device is configured as described above, if the excitation function of the 8G coil is lost in the control rod standby state,
The drawback was that the control rod drive shaft could not be held, causing the control rods to fall and, in some cases, lead to reactor shutdown.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and when the excitation function of the 8G coil is lost, all MG
The object is to provide a device that can excite a coil and hold a control rod.

In order to achieve such an object, the reactor control rod control device according to the present invention includes: a plurality of predetermined groups of lift coils; a first switching circuit that sequentially selects two groups of lift coils from the plurality of predetermined groups in a predetermined sequence; : Converts a three-phase electric power (7, 2) source into a direct current with a level based on a first reference current signal of a reference current source that generates a plurality of reference levels one by one,
A seventh electric crab unit that supplies the lift coils to two groups of lift coils via the first switching circuit; Movable gripper coils in the same number of groups as the predetermined plurality of groups: Moveable gripper coils in two groups of the predetermined plurality of groups A second switching circuit that sequentially selects in a predetermined sequence; converts the three-phase power supply into a DC current with a level based on the second reference current signal of the reference current source, and passes this through the second switching circuit to the two groups of DC currents; supplying power to the movable gripper coils; stationary gripper coils in the same number of groups as the predetermined number of groups; and provided corresponding to the plurality of predetermined groups of stationary gripper coils, respectively, and supplying the three-phase power supply to the movable gripper coils; , a third converter converting the reference current source into a DC current having a level based on each separate third reference current signal group having the predetermined sequence, and supplying the direct current to each of the plurality of predetermined groups of stationary gripper coils. Electric crab knit; Based on the second and third reference current signals, the two groups of control rods are inserted and withdrawn via each electric crab unit, and the third reference current signal group for those other than the insertion and withdrawal operations is In a nuclear reactor control rod control device that energizes the stationary gripper coil via the third electric crab unit: an output terminal of each of the third electric crab units, an input terminal of the first electric crab unit, and the second switch. the second switching circuit is connected to an input terminal of the circuit so that when a failure occurs in which a DC output signal is not generated from any of the third electric actuators, the movable gripper coils of all groups are energized upon detecting this failure; A failure detection unit is provided that controls all connections and at the same time invalidates the first reference current signal to forcibly control the energization of the second electric capacitor so that a predetermined DC holding current is supplied from the first electric capacitor. It has a configuration characterized by the following.

The present invention will be described below with reference to three embodiments j/CfE shown in FIG. q of the accompanying drawings.

In FIG. 9, the difference from FIG. 3 is that the failure detection unit tθ
The failure detection unit 90 is equipped with the third electric kaninit 30,! ;2 and 9 output points of sq.

94' and 9AIC are connected to input the current value signals from these, and the failure detection section TO is connected to the second electric capacitor lI6 and input to the third electric capacitor jθ.

There is an abnormality in the output current of either 52 or 51I, for example '
When it detects that no DC is flowing, the second power unit) &
Regardless of the first reference current signal from the reference current source Lu to A, in other words, in order to make the first reference signal invalid, a predetermined DC holding current is applied to the second set of loads θ via the line 9g. Issue a command signal to supply. Also, the second switching circuit that simultaneously distributed the DC sequence to one of the second set of loads θ divided into multiple groups? 4 (which may be composed of a cyrisk or a contactor) is issued a command signal to simultaneously energize all of the second set of loads -0 via the line /θO.

In this system, the control rod insertion/extraction function is the same as the conventional system, but if the excitation function of the 8G coil holding the control rod is lost (ts), this is detected and the second It has a unique function of preventing the control rod from falling by energizing multiple groups of MG coils at the same time using the electric crab.

For example, if the third electric control unit 5θ fails and the current necessary to hold the control rods is no longer supplied to the load (SG coil)/2 of the first group of the first set IO, an abnormality in this current, i.e. The failure detection unit 90 detects the absence at the output point q2, and from the signal pressure on the line IOθ from the failure detection unit qo, the first switching circuit 6 is composed of a plurality of groups, for example, the first to third groups shown in the figure. The connections are controlled so that all of the second set of loads (M() coils) 20 that have been selected are simultaneously selected. On the other hand, the second
The crab unit lI6 is the fault detection section 9θ or the signal 9
g commands to supply a planned DC holding current that simultaneously energizes all of the second set of loads (M() coils) 2θ. Therefore, even if the 3rd power unit (3rd power unit) 1θ fails and the stationary latch g (Fig. 1) of the 1st group tries to open, the movable latch closes to grasp the control rod drive shaft, so the control rod does not fall and remains constant. (/6) Held in position. Here, it is important that the MG coil not only the first group 22 but also the second group 2'l and the third group rollers are all energized and operate safely.

The above example is a case where a failure occurs in the third electric power unit (go), but even if a failure occurs in the third power unit (y) or Stt, the control rods are held in the same way. Further, it goes without saying that even if a failure occurs in two or more of the third electric crab units SO, SCO, and STI, the control rods will be safely held.

As described above, according to the present invention, the first set of loads l0 (8G
The system is configured to monitor abnormalities in the current supplied to the coils), and if an abnormality is found, all of the second set of load coils θ (MG coils) are energized by the second electric crab unit, thereby preventing unnecessary control rods from falling. This has the effect of preventing unplanned reactor shutdowns.

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view of the control rod drive mechanism in a nuclear reactor.
FIGS. 2(a) and (b) are diagrams showing the operation sequence of the control rod drive mechanism, FIG. 3 is a block diagram of a conventional nuclear reactor control rod control device, and FIG. 9 is a diagram according to an embodiment of the present invention. FIG. 2 is a block diagram of a reactor control rod control device. In the figure, 10 is the first set of loads (S a :F i#
), 20 is the second set of loads (MG coil), 30 is the third set of loads (lift coil), Gθ is the three-phase power supply, 11.2 is the first set of loads
Electric power unit, lI6 is the first power unit, 5θ, tacho and SII are the third power unit, 6 is the reference current source, 6
6 is a first switching circuit, t6 is a second switching circuit, /2. :l:
l and 32 are the first group loads, lg. 2g and 3g are second group loads, /A, 24 and 36 are third group loads, and 9θ is a failure detection section. In the drawings, the same reference numerals indicate the same or corresponding parts. Agent Shin Kuzuno - (/9)

Claims (1)

[Claims] a predetermined plurality of groups of lift coils; a first switching circuit that sequentially selects two groups of lift coils from the predetermined plurality of groups in a predetermined sequence; a first electric crab unit that converts the DC current to a level based on the reference current signal and supplies it to two groups of lift coils via the first switching circuit; movable gripper coils in the same number of groups as the predetermined plurality of groups; a second switching circuit that sequentially selects two groups of movable gripper coils among the plurality of groups in the predetermined sequence; converts the three-phase power supply into a direct current at a level based on a second reference current signal of the reference current source; This is passed through the λ-th switching circuit to 2
A first electric crab unit that supplies movable gripper coils of a group: a stationary gripper coil of the same number of groups as the predetermined plurality of groups; and a first electric crab unit provided corresponding to the stationary gripper coil of the predetermined plurality of groups, a third electrical unit that converts each of the DC currents to a level based on each separate third reference current signal group having the predetermined sequence from the reference current source and supplies the DC current to each of the plurality of predetermined groups of stationary gripper coils; ; the insertion and insertion of two groups of control rods through each of the type crab knits based on the first, second and third reference current signals;
While performing the extraction operation, the third
In a nuclear reactor control rod control device in which a group of reference current signals energizes the stationary gripper coil via the third electric crab unit other than the insertion/extraction operation: the output terminal of each of the third electric crab units, the first electric crab unit; Electric crab input terminal,
and the third switching circuit is connected to the input terminal of the second switching circuit.
In the event of a failure in which a DC output signal is not generated from any of the electric crabs, the second switching circuit is fully connected and controlled so that the movable gripper coils of all groups are excited upon detecting this, and at the same time the second reference current signal is output. A nuclear reactor control rod control device comprising: a failure detection unit that forcibly controls energization of the second electric cylinder so that a predetermined direct current holding current is supplied from the second electric cylinder by disabling the .