JPS5999293A - Control device for 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.
This 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 are attached to the outside of the reactor pressure vessel: a lift coil/, a movable gripper coil C (hereinafter referred to as Ma coil), and a stationary gripper coil (hereinafter referred to as SG coil) 3. Operate the excitation armature housed in the furnace pressure vessel. That is, the movable gripper armature and the stationary gripper armature actuate latches 7 and latches that engage the troughs or 6a of the control rod drive mechanism when the MG coil coil and 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 is excited, and raises and lowers the control rod drive shaft 6 (moves in the withdrawal direction).
Used to lower (move in the insertion direction).

In addition, /fi is the lift magnetic pole, 3a is the stationary gripper magnetic camellia, the left is the stationary gripper armature, 7
a is a movable latch link, and ga is a stationary latch link.

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

The extraction sequence and insertion sequence of the control rod will be described below with reference to FIG. 1 and FIG. 2.

A: Withdrawal sequence (a) In the standby state, the SG coil 3 is energized and the stationary latch g is closed to hold the control rod drive shaft. [Figure 2 (a) - (state of (a)]) (C71M
Excite the G coil coil and close the movable latch 7. [
Figure 2 (a) - (b) states] () → SG coil 3
Demagnetize and release the stationary release. [Fig. 1 (state of at -(]→)] Excite the lift coil l, operate the lifted armature (3) near 9, and raise the movable gripper armature l. This causes the control supported by the mover full latch. Raise the rod drive shaft t in the direction of the arrow by one groove 6a of the control rod drive shaft. [Status shown in Fig. 2 (a)-)] (E) Excite the SG coil 3 and close the stationary latch S.
Close. [Figure 1 (a) - (state of (1))] ((to) MC) Demagnetize the coil 2 and release the mover full latch 7. [Figure 1 (state of al- (to)]) ) Demagnetize the lift coil I and lower the lift armature in the direction of the arrow. [Figure 1 (a) - (state of G1)] (A) Repeat the operations from (B) to (G).

B: Insertion sequence (a) In the standby state, the SG coil 3 is energized, the stationary latch is closed, and the control rod drive shaft 6 is held. [Status of Figure 2 (b) - (A)] (B)
Energize the lift coil to raise the lift armature in the direction of the arrow. (*j State of Figure (b)-(B)) (e) (No I MG coil, 2ヲMl [Then, close the movable latch 7. [Figure 2 (h)-State of G = 1] (
) Demagnetize the SG coil 3 and release the stationary latch g. [Status shown in Fig. 2 (b3-)] (@ Demagnetize the lift coil l, lower the lift armature 9, and lower the movable gripper armature l. Now, move the control rod drive shaft 6 into its groove A-a. Lower it by one position in the direction of the arrow. [Fig. 2 (b) = (state of (e))] (c) Excite the SG coil 7 and close the stationary latch g. [Fig. 2 (b) - (state)] (g) Demagnetize the MG coil 2 and release the movable grip latch 7. [Fig. 2 (b) - (g) state] (Force (
Repeat operations from (b) to (g).

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

The control rod controller supplies direct current to the three types of coils in the control rod drive mechanism. Conventionally, a device of this type is shown in FIG. 3. In the same figure, load/'0. :lθ and 30 correspond to the three types of coils of the control rod drive mechanism described above. That is, the load IO corresponds to the SG coils of a plurality of control rod drive mechanisms, and the load IO corresponds to the SG coils of a plurality of control rod drive mechanisms.
0 corresponds to the MG coils of the plurality of control rod drive mechanisms, and the load 30 corresponds to the lift coils of the plurality of control rod drive i#I mechanisms. Each load is derived from 7 groups of loads. That is, the first
The load 10 of the set is the first? V￥l,! , the second group keg, and the third group/A SC) coil. Konera group 3/2゜1
A load of 1 J/A requires a DC sequence at the same level (when the SG coil is excited to hold the control rods), and one control rod is driven for each group, but the control rods are
, In order to hold the control rods in a fixed position even during periods when they are not activated, it is necessary to energize the SG coils of all control rod drive mechanisms, so switching operations are performed as in the 2nd!11 and 3rd set of loads. I don't know.

Similarly, the second set of load coils θ is composed of the tWf-cog, the first group cog, and the MG coil of the third group 2A.

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. Therefore, the seventh group of control rods is driven by a seventh group of control rod drive devices including a first group of SG coils, a first group of MG coils, and a seventh group of lift coils. The first group of control rods is driven by a second group of control rod drive mechanisms including a second group of SG coils, MG coils, and lift coils. Similarly, the control rods of the seventh group are not driven because the control rod drive device of the third group is busy.

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.

(7) Three-phase power is generated by multiple heavy crab units lIλ, gA, left θ,! It is supplied to Ko and Hitag. This electric kaninit supplies serum and output at predetermined multi-level (usually three levels) values based on a reference current signal from a reference current source to be described later. The first electric crab unit 11.2 passes through the three-phase Raijin tI through a single line illustrated as <22
Receives three-phase power from o. The first regular unit is an electric unit for providing a DC sequence to the lift coils of a plurality of control rod drive mechanisms. The second output from the three-phase power source θ is passed through the line to the third power unit DA 6.
supplied to The first power unit is an electric unit for providing direct current to the MG coils of the plurality of control rod drive mechanisms. Sower line from the 3rd output Gede from Yo-phase power supply II &! rt, sr.

Three-phase power is supplied to the three separate electrical kaninits 3θ, octopus, and tag through the pump. Electric crab knit left O1 left side and tag are t1'? It is an electric crab unit (g) for providing direct current to the sG coils of several control rod drive mechanisms in a predetermined sequence. Each load 1.2. l11. ．． And/6 separate electric crab knits, to,! r:l, and! The reason for this is that during the operation of the control rod drive system, a group of
This is because when the rods are inserted or withdrawn, it is necessary to energize the SG coils of the control rod drive mechanisms of the remaining control rod groups to hold the control rods in one position. For example, if the control rod drive mechanism of the first group should be energized, that is, the zero load (SG coil) of the seventh group of the first set lθ
/, 2, the load of the first group of the second set λθ (Ma micoil, 2
2nd and 3rd button? When fF of 0, loads of 7 groups (lift coils, This is because it is necessary to prevent the control rods driven by the control rod drive mechanism from falling into the reactor.

6.2 usually has 1.7 levels: zero current value (the current value that demagnetizes the coil), low limit current value (the current value required to hold the control rod), and total current value (the current value that keeps the control rod in place). This is a well-known reference current source that generates a reference current signal in a predetermined sequence with a current value (current value required only when driving). DC is supplied to the load. The reference current source t connects the seventh reference current signal to the first one through the line A'l.
Supplied to Denkaninitz Q2. 1st Electric Power Unit Guco,
That is, the first reference voltage signal is used to adjust the DC output from the electric crab unit for the lift coil of the control rod drive mechanism. The DC output from the first power unit λ is applied to the loads 32, 3q and 7 of the first group, the first group and the F3 group.
A track to one of the two? @7 city crabnit lI as sent via ff, za θ, and g
The output from the first switching circuit 66 (for example, one controlled by an external circuit) ll? l: Therefore, selected.

Similarly, the second reference current signal from the reference current source 62 is supplied to the MG coil electric crab units 1/6 of the plurality of control rod drive mechanisms via lIO#q4t. The DC output from the second city unit tog 6 is supplied to the second switching circuit 7A, and the loads 22 . - To one of the two A and 2A,
)1 each track A, ? .

Direct current is supplied via 70 and 7.2.

The 6 reference current sources are connected to the 3rd N crab 3-nit 5θ, 52 and the left gear by the lines gtt, gb and rg, which are the type crab knits for the tsurezo fl, s() coils, and three separate 3rd base current signals. ((i'3.L, all groups are supplied with the same DC level reference current signal in the holding state f).Separate third reference current signals are supplied to the three groups. The reason why groups are supplied is that when a group of control rods is inserted or withdrawn, the SG coils of the control rod drive mechanisms of the remaining control rod groups are energized to hold these control rods in the 1st position. This is because it is necessary.
ffi/, M and the second electric circuit may be constructed as thyristor type converters, and the first and second switching circuits may also be constructed as thyristor type switching devices.

Conventional devices are configured in an up-and-down manner, so if the excitation function of the SG coil is lost in the control rod standby state, the control rod drive shaft cannot be held.
The drawback was that the control rods could fall and, in some cases, cause the reactor to shut down.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and when the excitation function of the SG coil is lost, the entire group of MGs is controlled by a newly installed failure detection section.
The purpose of this invention is to provide a device that can excite coils all at once and hold control rods.

In order to achieve such an object, a nuclear reactor control rod control device according to the present invention includes a plurality of predetermined groups of lift coils: one group of lift coils among the plurality of predetermined groups is 1lf in a predetermined sequence.
A first switching circuit that selects the i-th order; converts the three-phase power supply into a direct current at a level based on the first reference current signal of the reference current source,
A seventh electric crab unit that supplies this to a group of lift coils by the first switching circuit; a movable gripper coil in the same number of groups as the predetermined plurality of groups; the three-phase current is based on the second reference current signal of the reference current source; a second electric crab unit that converts the DC current into a level DC current and supplies it to the movable gripper coil (lco) to excite them all at once;
The stationary gripper coils of the predetermined plurality of groups are provided corresponding to the stationary gripper coils of the predetermined plurality of groups, and each separate third coil having the predetermined sequence from the reference current source is connected to the three-phase power source. a plurality of third electric crab units each converting into a DC current at a level based on a group of reference current signals and supplying the DC current to each of the predetermined plurality of groups of stationary gripper coils;
When the output terminal of the electric crab is connected to the output terminal of the electric crab and the input terminal of the second electric crab, and a DC output signal is not generated from either of the third electric crab, a splinter is detected and the second electric crab is connected. 7. A failure detection unit configured to forcibly energize and supply a predetermined direct current holding current to the plurality of groups of movable gripper coils so as to excite them all at once; Second. Insertion/extraction operations of a group of control rods are performed on the third reference current signal, and the third reference current signal group other than the insertion/extraction operation is transmitted to the stationary via the J'fPt crab unit other than the insertion/extraction operation. It has a configuration characterized in that the gripper coil is energized.

The present invention will be explained below with reference to the embodiment shown in Figure q of the accompanying drawings.

The first point that differs from FIG. 3 in FIG. 2. And tag output current detection point? Ko,? and 9B to input the current value signal from the connector, and further connect to the failure detection section 90VL and the second power unit (Third power unit) &l17. tco, and S
When detecting an abnormality in the output current value of one of the output currents of the second unit, for example, that no current flows, the output current is sent to the thyristor of the second city unit regardless of the second reference current signal from the reference current source t2, i.e. In order to invalidate the second reference current signal, an energization command is generated via line qg.

The second difference from the conventional device shown in FIG. 3 is that the DC output from the second power unit tog 6 is changed to Pl'! The second switching circuit qg (?l
? , Figure 3) was removed, and the second electric crab was commonly connected to the MG coil loads Coco, 2, and Colo.

With the above configuration, the second power unit A can simultaneously energize the three groups of MO coil negative loads of the first set in the same DC sequence. That is, three groups of M() coils 22, . 24' and 2B are all excited at the same time, so that all three groups of mover pulleys (see Figure 2) are energized at the same time.

On the other hand, the first and third sets of loads /0° and 3θ in FIG. 3 are energized in the same DC sequence as in FIG. Therefore, even though the movable latch energizes all three groups at the same time, the control rod drive mechanism
The function that only one group is driven and the other two groups are held at a fixed position is different from the conventional device shown in FIG.

The reason for kneading is as follows. That is, for example, if the control rods of the 7th group are to be driven, the control rod drive mechanism of the 1st group performs the insertion or withdrawal operation of the control rods according to the normal operation sequence (is) shown in FIG. However, since the SG coils /DA and /A of the control rod drive mechanisms of the second and third groups continue to be excited, the control rods of the second and third groups are held at a constant position. However, the mover pull latches of all the control rod drive mechanisms that are held in a fixed position are simply closed or opened simultaneously in synchronization with the movable latch 7 of the control rod drive mechanism of the seventh group that is to be energized. Since the lift coil l remains demagnetized, the control rod does not move.

In this system, as described above, there is no control rod insertion/extraction function, but if the excitation function of the SG coil holding the control rod is lost, the kneading is detected and the MG It has a unique function of preventing the control rod from falling by energizing the coil and holding it with a movable latch.

For example, if the 3'11j-th power unit θ has a failure t,..., the z-th
For the first group load (SG coil) l of set lθ.

If the current required to hold the control rods is not supplied, is this current abnormality detected by the failure detection unit? O is the output point q2(tA
), the failure detection unit te θ issues a thyristor energization command to the normal first electric crab unit 4 (A) via the line ? 2'
1, and 26 at the same time (in this case, the control rods of the second and third groups are not being inserted or pulled out, but are in the holding state).
Since the stationary latch is inside, the stationary latch is held by both movable latches 7]. Therefore, even if the stationary latch t (Fig. 1) attempts to open due to a failure in one of the third city unit levers θ, the movable latch closes to grasp the control rod drive shaft 6, so the control rod does not fall and remains constant. held in position. Also, the third lightning crab! It is clear that even if a failure occurs in the control rods 2 and 3, the control rods of the second group and the third group, respectively, can be held.

As described above, according to the present invention, the DC output of K, fl'', 2M, crab knit lI:1 is supplied to the second set of loads, 2O, without using a switching circuit, and the negative load l of the first set of SG coils is supplied. The structure is configured so that an abnormality in the current supplied to the SG coil is monitored, and if an abnormality occurs, a command to energize is issued to the power unit 2, so as soon as an abnormality in the input current of the SG coil is detected, the MG coils are turned on all at once. This has the effect that a highly reliable control rod control system cannot provide, in that it energizes the control rods, holds the control rods from falling, and prevents the reactor from shutting down.

[Brief explanation of drawings]

m/Figure is a schematic cross-sectional view of the control rod drive mechanism in a nuclear reactor.
Figures 2 (a) and (b) are diagrams showing the operation sequence of the 1+ control rod drive mechanism, Figure 3 is a block diagram of a conventional reactor control rod control device, and Figure 9 is an embodiment of the present invention. 1 is a block diagram of a nuclear reactor control rod control device according to FIG. In the figure, lθ is the brush 1 set load (sG coil), -〇 is the 2nd set load (MG coil), 3θ C 3rd #, fl load (lift coil) %gθ is the three-phase power supply, 4/co is the The first one is crab knit, the second one is crab knit,! θ, 5, and S are the brush 3 electric crab units, 6 is the reference current source, 6A is the first switching circuit, l, 22°, and J2 are the 7th group load,! ta, Jda, and 3g are the second group loads, /4.2&, and 3
6 is a third group load, and 90 is a failure detection section. In the drawings, the same reference numerals indicate the same or corresponding parts. Agent Shin Kuzuno - Flame 1 Figure-55: Light 2 Figure 5 (CI)

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 seventh electric crab unit that converts the DC current into direct current and supplies it to two groups of lift coils by the first switching circuit; movable gripper coils in the same number of groups as the predetermined plurality of groups; a second electric controller that converts the DC current into a DC current at a level based on a second reference current signal of the power source and supplies the DC current to the movable gripper coils to excite them all at once; the predetermined plurality of groups of stationary gripper coils; the predetermined plurality of stationary gripper coils; a third reference current signal corresponding to each stationary gripper of the group, each converting the three-phase power supply into a direct current with a level based on a third reference current signal having a predetermined sequence from the reference current source; and a plurality of third electric crab units that respectively supply the same to the predetermined plurality of groups of stationary gripper coils; and an output terminal of each of the third electric crab units;
and detecting the input end of the second electric power unit and forcibly energizing the first power unit to supply a predetermined DC holding current to the plurality of groups of movable gripper coils to excite them all at once. a failure detection section; the first, second, . Insertion/extraction operations of the second group of control rods are performed on the third reference current signal, and the third reference current signal group other than the insertion/extraction operation is transmitted to the stationary via the third electric crab unit other than the insertion/extraction operation. A nuclear reactor control rod control device characterized by energizing a gripper coil.