JPS5913986A - Control rod drive hydraulic device - Google Patents

Abstract

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

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a control rod drive hydraulic system for a boiling water nuclear reactor (hereinafter referred to as BWR).

[Technical background of the invention]

A conventional example will be explained with reference to FIG. FIG. 1 is a schematic diagram of the control rod drive hydraulic system. In the figure, 1 indicates the reactor pressure vessel. Inside this reactor pressure vessel 1 (= is installed a reactor core 3 consisting of a plurality of fuel assemblies (not shown), control rods 2, etc. The control rods 2 are attached to the bottom wall IA of the reactor pressure vessel 1. Fixed control rod drive mechanism (hereinafter referred to as CHD)
) 4 for insertion or withdrawal.

The CRD 41- is connected to a control rod drive hydraulic device installed outside the reactor containment vessel 7 via an insertion pipe 5 and an extraction pipe 6.

Next, the control rod drive hydraulic system will be explained. 9 in the diagram
#iA dynamic water supply mechanism 1. This drive water supply mechanism 9
The control rod drive water pump 1 is connected to any condensate storage tank 10 and pumps the condensate in the condensate storage tank 10 as drive water. The discharge side of this control rod-driven water pump 11 is a flow control valve 13.
It is connected to the driving water pipe 15 (2) via a master control unit 12 having a pressure regulating valve 14, and to the insertion pipe 5 and the withdrawal layer 6 via a water pressure control unit 16.

The flow control valve 13 has a function of adjusting the drive water pumped from the control rod drive water pump 11 to a constant amount a,
The driving water that has passed through the flow control valve 13 is adjusted to a constant pressure by the pressure regulating valve 14, and is then connected to the drive water piping 15 described in (nII). ill ice water pressure control unit 16
Drive water piping 1 connected to insertion piping 5 and withdrawal piping 6
The accumulator 20 is inserted into a pipe 19 that is spun before a direction control valve for selectively supplying the driving water from the pipe 5 to the pipe 5 for insertion or the pipe 6 for withdrawal. Further, a scram valve 21 is inserted between the accumulator 20 and the insertion pipe 5. The directional control valve device 17
are direction control valves 17A, 17T3. J7c.

77D, and is connected to a drainage device 23 via a drainage pipe @=2, and a peristaltic water pipe 24 is provided on the downstream side of the pressure regulating valve 14, and the insertion pipe 5. Furthermore, a ladder 26 is connected to the scram via a scram outlet valve 25 to the extraction pipe 6.
is connected. In addition, during G 27.28.1!9゜30
indicates a check valve.

The control rod drive hydraulic device 4 with the above configuration (control rod 2
into the reactor core 3 (= when inserted, the directional control valve device 1 is inserted by the control rod insertion number 48 from the reactor control device (not shown)
7 directional control valve 12A.

17B opens. and the control rod driven water pump 11
The pulsating water is pressure-fed by the flow control valve 13 and the pressure control valve 14 and adjusted to a constant pressure of +11 pm. ) 4 Supplied to the lower part of Noviston 4A. Then, the control rods 2 are inserted into the reactor core 3 (2) by raising the piston 4A by -L.
The water above A flows out to the drainage device 23 via the extraction pipe 6, the same direction control valve 77B, and the drainage pipe 22.

Next, the case where the control rod 2 is pulled out will be explained. As in the case of control rod insertion, 1) Directional control valves 17C and 17D of the directional control valve device 17 are opened by the control rod withdrawal signal from the reactor control device↑
Ru. Then, the control rod-driven water pump 11 pumps the water, and the flow rate adjustment valve 13 and the pressure adjustment valve 14 provide a constant device.
The driving water adjusted to a constant pressure is supplied to the piston 4 via the driving water piping 15, the L direction control well 17C, and the extraction piping 6.
A is supplied upward. As the piston 4A descends, 1) the control rods 2 are pulled out from the core 3; The water below the piston 4A is connected to the insertion pipe 6. Said direction control arrival valve 17
D and drains through the drain pipe 22 to the drain device 231'.

Further, during scram, the scram population valve 21.degree. scram exit valve 25 is opened, high pressure scram water from the accumulator 20 is sent to the insertion pipe W5, and the control rod 2 is quickly fully inserted.

[Problems with background technology]

According to the above configuration, for example, even if the control rod insertion No. 48 is completed and the control rod insertion signal from the reactor control device is completed, the directional control valves 17A and 17B may not close.
As long as driving water is supplied, the control rod insertion operation continues (2).Also, when withdrawing the control rod, as in C2, there is a possibility that the directional control valves 17C and 17D do not close even after the withdrawal is completed. , the control rods will continue to be withdrawn, the reactor's output will increase, and the reactor will come to an emergency shutdown.This will reduce the plant's operating rate, which will ultimately impair the reactor's integrity and safety. There is a fear.

[Purpose of the invention]

The first objective of the present invention is to prevent malfunctions such as excessive insertion and withdrawal of control rods even if the directional control valve malfunctions, thereby improving the integrity and safety of the reactor. The purpose of the present invention is to provide a control rod driven hydraulic device with 11 control rods.

[Summary of the invention]

The control rod separation hydraulic device according to the present invention includes a drive water supply mechanism that supplies drive/l (T) to the control rod drive mechanism, and a drive water supply mechanism that is inserted between the drive water supply mechanism and the control rod drive mechanism. From the water supply mechanism to the control rod drive mechanism (: a water pressure control unit that controls the direction of the supplied drive water, and a drive water pressure that is provided between the drive water supply mechanism and the water pressure control unit to adjust the drive water pressure) an adjustment mechanism, a control rod position detection circuit that detects the position of the control rod, and a control rod position detection circuit that receives an over-insertion or over-extraction signal from the control rod position detection circuit and generates a drive water pressure reduction signal as a drive water pressure adjustment mechanism (second drive water pressure adjustment mechanism). This configuration includes a control circuit for outputting.

In other words, the control rod position detection circuit detects the position of the control rod and outputs a signal indicating excessive insertion or withdrawal of the control rod to the control circuit.The control circuit receives the above signal and detects the control rod position. It is configured to output a hydraulic pressure reduction (iq number) to reduce the driving water pressure and stop the control rod insertion or withdrawal operation.

Therefore, for example, even if the water pressure control unit malfunctions, it is possible to prevent the control rod from being inserted or withdrawn more than the set value.
The health and safety of nuclear reactors can be greatly improved.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIG. 2V. FIG. 2 is a schematic diagram of the control drive hydraulic device. 1 in the diagram
01 indicates the reactor pressure vessel f.

Inside this reactor pressure vessel 101, a reactor core 103 consisting of a plurality of m1 aggregates (not shown), a control 5102, etc. is installed. The control rod 102 is the reactor pressure vessel 10
The control rod drive mechanism (hereinafter referred to as C) fixed to the bottom wall 101A of
Insertion or extraction is performed by HD 104 (referred to as HD). The above CMD104 has an insertion pipe 105.
And the extraction arrangement 'ft106? Reactor containment vessel 1 through
07 Outside (2 installed control rod drive hydraulic system H darkness is connected.

Next Shini above control rod drive hydraulic system! -0-4 will be explained. In the figure, 109 indicates a driving water supply mechanism.

This driving water supply mechanism 109 is connected to a condensate storage tank 110 and is connected to the condensate storage tank 110.
It is composed of a control rod drive water pump 111 that pumps condensate in the water as drive water. The discharge side of this control rod driven water pump 111 is connected to a driving water pipe 115C via a master control section 112 having a flow IL regulating valve 113 and a pressure regulating valve 114 as a murmuring water pressure regulating mechanism 1i.
=, and is connected to the insertion pipe 105 and the withdrawal pipe 106 via the water pressure control unit 116.

The flow rate regulating valve 113 has a function of regulating the driving water pumped from the control rod driving water pump 111 to a constant flow rate. The pressure is adjusted and the water is sent to the drive water piping 115. The water pressure control unit 116 is connected to the insertion pipe 105 and the withdrawal pipe 106, and selectively transfers the drive water from the drive water pipe 115 to the insertion pipe 105 or the withdrawal pipe 106 (=the supply direction control valve device 117 and the Ail). The insertion pipe 105 branches from the flow side to the flow dipping valve 113 and passes through the scram filling connection 118.
Accumulator 1 inserted in piping 119 connected to
It is equipped with 20. Further, a scram inlet valve 121 is inserted between the accumulator 120 and the insertion pipe 105. The directional control valve device 117 is composed of directional control valves 117A, 117B, 117C, and 117D, and is connected to a drainage device 1231' via a drainage pipe 122.
:,It is connected. And B11 pressure regulating valve 114
A cooling water pipe 124 is provided on the downstream side, and
The insertion pipe 105 (=connected. Furthermore, the extraction pipe 106ζ2 is connected to a scram header 126 via a scram outlet valve 125. Note that 127 in the figure
128, 129, 130 indicate check valves.

The CRD 104 is provided with a control rod position detection circuit 13) for detecting the position of the control rod 102. :+Control circuit 13 that processes the detection signal from the control rod position detection circuit 131 of the rainbow lever and outputs the signal to the pressure regulating valve 114.
2 is provided. This control circuit 132 compares the detection signal from the control rod position detection circuit 131 with a preset signal, and sends a signal to the pressure regulating valve 114 if the control rod 102 is over-inserted or over-extracted from the set position. It has a comparison calculation circuit 133 that outputs. Then, based on the signal from this comparison calculation circuit 133, the pressure m is adjusted by the valve 1.
14 is further opened to lower the drive water pressure and stop the control rod insertion or control rod withdrawal operation.

According to the control rod drive hydraulic system-button with the above configuration, when the control rods 102 are inserted into the reactor core 103, the directional control valve device 117 is activated by a control rod insertion signal from the reactor control device (not shown). The directional control valves 117A and 117B open.Then, the driving water is pumped by the control rod driving water pump 11 and adjusted to a constant flow rate and constant pressure by the flow rate sub-part valve 113 and the pressure regulating valve 114. Piping 115
, is supplied below the piston 104A of the CRDJ 04 via the directional control valve 117A and the insertion pipe 105. Then, the piston 104 is raised (secondary control rod 102 is inserted into the reactor core 103. On the other hand, the water above the piston 104A is drained through the withdrawal pipe 106, the directional control valve 117B, and the drain pipe 122') to the drainage system. 1
Leaked on 23rd.

Next, the case where the second control rod 102 is pulled out will be explained.

As in the case of control rod insertion, the directional control valve 11'I of the directional control valve device 112 is activated by the control rod withdrawal signal from the reactor control device.
C, 117D opens. Then, the drive water is pressure-fed by the control rod drive water pump 111 and adjusted to a constant pressure by the flow control valve 113 and the pressure control valve 114, and is then drawn out to the drive water piping 115-h directional control well 117C. It is supplied above the piston 104A via the pipe 1oe. And the descent to this piston 104 is also =
As a result, the control rods 102 are pulled out from inside the reactor core 103. And the water below the piston 104 is connected to the insertion pipe 105,
It flows out to the drainage device 123 via the direction control valve 117D and the drainage pipe 122.

In addition, at the time of scram, the scram population valve 121 and the scram estuary valve 125 are opened, and the pressure scram water from the accumulator 120 is sent to the insertion pipe 105, and the control rod 10
2 is rapidly fully inserted.

Next, when the control rod is inserted or withdrawn, the direction control valve 117A, 117B or 117C is activated.

A case where the valve 117D malfunctions and does not close will be explained below. The position of the control rod 102 is determined by the control rod position detection circuit 1.
31 is constantly detected. and control circuit 132
The control rod position detection circuit 1 is determined by the comparison calculation circuit 133 of
The detection signal from 31 is compared with a preset setting signal. Therefore, the direction control valve 117A.

If 117B, 117C, or 117D malfunctions and the insertion or withdrawal operation continues, the above detection signal is set (over No. 1; no 1), and the comparator circuit 131 sends water to the miJ pressure regulating valve 114. A low pressure signal is output. In response to this signal, the pressure regulating valve 114
The valve opens further and the driving water pressure decreases. This non-hydraulic pressure drop causes the control rod insertion or control rod withdrawal operation to stop.

That is, when inserting or withdrawing the control rod a, the control rod position detection circuit 13) detects the position of the control rod 102, and the comparison calculation circuit 133 of the control circuit 132 (secondarily, the detection signal from the control rod position detection circuit 131) and the detection signal from the control rod position detection circuit 131 are detected. Comparing with a preset setting signal, if the detected position of the control rod 102 is over-inserted or over-extracted from the set position, a driving water pressure reduction signal is output to the pressure regulating valve 114 to close the pressure regulating valve 114. Furthermore, the valve is closed to reduce the driving water pressure.

Therefore, even if the directional control valve 117, 117B, 117C, 117D malfunctions and does not close when the control rod is inserted or withdrawn, the control rod 1
02 can be prevented from being over-inserted or over-extracted.

For example, it is possible to prevent incidents such as a -L increase in reactor output due to excessive withdrawal, or an emergency shutdown of the reactor.
It can greatly improve the health and safety of nuclear reactors.

Next, another embodiment will be described with reference to FIG.

That is, the pressure regulating valve 114 in the above embodiment is provided with a bypass valve 134 which is always closed to form a drive water pressure A adjustment mechanism, and the comparison calculation circuit 133 of the control circuit 132 detects the detection signal from the control rod position detection circuit 13. and a preset setting signal, and when the detection signal exceeds the setting signal, a signal is output to the bypass valve 134 to open the bypass valve 134. The structure is such that the drive water pressure is lowered through the valve and the control rod insertion or withdrawal operation is stopped.

Therefore, as in the previous embodiment, the directional control valve J J 7A is used at the end of control rod insertion or withdrawal.

Even if 111B, 117C, or 117D malfunctions and does not close, do not over-inserte or withdraw the control rod 102! 7j th, and the health and safety of the nuclear reactor can be greatly improved.

〔Effect of the invention〕

Control according to the invention! ! A main body excitation hydraulic device, a drive water supply mechanism that supplies drive water to the control rod drive mechanism, and a drive water supply mechanism that is inserted between the drive water supply mechanism and the control rod drive mechanism and from the drive water supply mechanism to the control rod drive mechanism. (2) A water pressure side unit that controls the direction of the supplied driving water; a driving water pressure adjustment mechanism that adjusts the driving water pressure that is provided between the driving water supply mechanism and the water pressure control unit; A control rod position detection circuit that detects the position 111 degrees, and a control circuit that receives an over-insertion or over-extraction signal from the control rod position detection circuit and outputs a drive water pressure drop signal to the drive water pressure adjustment mechanism. This is a fully equipped configuration.

That is, the control rod position detection circuit detects the position of the control rod, and outputs No. 4N indicating excessive insertion or withdrawal of the control rod to the control circuit. The control circuit is configured to input the above signal and output a drive water pressure reduction signal to the drive water pressure adjustment mechanism to reduce the drive water pressure and stop the control rod insertion or withdrawal operation.

Therefore, for example, even if the water pressure control unit malfunctions, it is possible to prevent the control rods from being inserted or withdrawn more than the specified number.
The effects are great, such as greatly improving the health and safety of nuclear reactors.

[Brief explanation of drawings]

Fig. 1 is a schematic system diagram of a control rod drive hydraulic system showing a conventional example, Fig. 2 is a schematic configuration diagram of a control rod drive hydraulic system showing an embodiment of the present invention, and Fig. 3 shows another embodiment. It is the same figure as above. 109... Drive water supply mechanism, 114... Pressure adjustment valve (drive water pressure adjustment mechanism), 116... Water pressure control unit % 131... Control rod position detection circuit, 132...
control circuit.

Claims (2)

[Claims] (1) A drive water supply mechanism that supplies drive water to the control rod separation mechanism, and a drive water supply mechanism that is inserted between this drive water supply mechanism and the control rod drive mechanism (two are inserted and supplied from the drive water supply mechanism to the control rod drive mechanism). a water pressure control unit that controls the direction of the drive water being applied; a drive water pressure adjustment mechanism that is provided between the drive water supply mechanism and the water pressure control unit that adjusts the drive water pressure; and a control that detects the position of the control rod. It is characterized by being equipped with a rod position detection circuit and a control circuit which receives an over-insertion or over-extraction signal from the control rod position detection circuit and outputs it as a driving water pressure drop signal to the driving water pressure adjustment mechanism described in viI. A control rod driven hydraulic system. (2) The control circuit compares the signal from the control rod position detection circuit with a preset setting signal, and reduces the separation water pressure when the signal from the control rod position detection circuit exceeds the setting signal. 2. The control rod drive hydraulic device according to claim 1, further comprising a comparison calculation circuit that outputs a signal to the drive water pressure adjustment mechanism.