JPH02163696A - Vent device for hydraulic device for control rod driving - Google Patents

Abstract

PURPOSE:To drastically shorten an air vent stage and to simultaneously decrease operators' exposure by supplying pressure water from a pressure water supply system to all control rod drive mechanisms to carry out a vent operation. CONSTITUTION:The pressure water supply system which can supply the pressure water, a pressure detector 34 which outputs a shut off signal 33, and a pressure shut off valve are provided. The pressure water for venting is supplied from the pressure water supply system 27 to all the control rod drive mechanisms (CRD) 2 to execute the air vent for a specified period of time at the beginning of the start of the vent operation. The detector 34 detects the pressure of the pressure water of the system 27 in excess of the set value and outputs the signal 33 when the above-mentioned pressure exceeds the set value during the vent operation. The signal 33 is inputted to the pressure water shut off valve and the supply of the pressure water from the pressure water supply system to the CRD 2 is stopped by this pressure water shut off valve. The air vent is executed by supplying the pressure water to the CRD 2 at the beginning of the start of the vent operation is such a manner and, therefore, the air vent stage is shortened and the operators' exposure is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a vent device for a control rod drive hydraulic device that drives a control rod drive mechanism using water pressure.

(Prior art) Generally, a boiling water type atomic reactor 1- is equipped with a MIl rod drive 1 (hereinafter referred to as CRD) driven by water pressure, and the control rods are inserted into the reactor core by this CRD. Driving water is supplied to the CRD from a control rod driving hydraulic device, and the driving water causes the control rod to move up and down.

FIG. 2 is a block diagram showing a schematic system of the structure of the control rod drive hydraulic device. In Fig. 2, J3 is connected to the CRD 2, which is installed in the chain part of the reactor pressure vessel (hereinafter referred to as RPV) 1, through the insertion pipe 3a3J and the withdrawal pipe 4.
It is connected to i control units 1 to 5 (hereinafter referred to as 1-I CLJ).

)-1ctJ5 is direction 1iIJW valve 5a, 6b, 6c,
6d, and when the R1 control rod 7 is inserted into the reactor core 8 during normal operation, the directional control valves 5a and 5b are opened in response to an insertion signal from the central control room. As a result, the drive water pipe 9
The driving water passes through the direction control valve 6a and the insertion pipe 3 from the UCR.
The control rod 7 is inserted into the reactor core 8 by pushing the drive screws 1 to 10 upwardly by water pressure. The water on the upper surface side of the drive screws 1 to 10 is discharged to the drain pipe 11 along with the upper back of the drive screws 1 to 10 through the extraction pipe 4 and the direction control valve 6b.

In addition, when withdrawing the control rods 7 from the core 8 during normal operation, the directional control valves (
3c and 5d are open. In response to this, driving water flows from the driving water piping 9 through the direction control valve 6G and the withdrawal piping 4 to the upper surface side of the driving screws 1 to 10, and pushes the driving screws 1 to 10 downward by water pressure. The control rod 7 is pulled out from the reactor core 8. As the drive screws 1 to 10 descend, the water on the lower surface of the drive piston 10 flows through the insertion pipe 3 and the direction control valve 6d.
The water is discharged from the drain pipe 11 through the -).

On the other hand, when there is an abnormality in the reactor, the scram exit valves 12 and 13 are opened by the scram signal from the reactor protection system, and the -C is stored in the art combulator 14.
The drive water flowing into the high L gas flows into the lower surface side of the C drive piston 10 through the squram population valve 12 and the insertion pipe 3,
The control rods 7 are urgently inserted into the reactor core 8. The water on the L-plane side of the drive screw 1-10 is discharged to the scram discharge header 16 through the withdrawal pipe 4, the scram outlet valve 13, and the scram riser pipe 15. This scram ejection header 16 (J
Connected to scram discharge container 17 'Ca5, f-I
The scram discharge water discharged from the CU 5 to the scram discharge header 16 is stored in the scram discharge container 17.

In addition, the code|symbol 18 shows a condensate storage tank, and the code|symbol 19 shows a driving water pump.

By the way, in order to make the control rod drive water pressure device function, it is necessary to fill the control rod drive water If device with water.
It is necessary to do ~. Conventionally, T-abend work after periodic inspection (hereinafter referred to as periodic inspection) according to operation plan 1~
Alternatively, the air vent 1 work after installation in a construction plant is completed is carried out for each CRD 2 one by one according to the following procedure.

First, the driving water supplied from the driving water pump 19 is passed through a flow rate regulating valve (hereinafter referred to as FCV) 21 and an FE force regulating valve (hereinafter referred to as jX lower PcV) 22 which are installed in a connecting pipe 20.
The water pressure is controlled to about 3 kg/cm by the driving water piping 9.
, flows into the lower surface of the drive piston 10 of the UCRD 2 through the directional control valve 6a and the insertion pipe 3. Drive screw]・N1
Part 1 of the driving water flowing into the lower surface of the driving piston 10
It leaks through gaps such as the seal ring, flows to the -V side of the drive piston 10, and further flows into the PVI at 1.

In this state, the insertion pipe Ben 1 to valve 23 are opened and closed several times to vent air between the HCu 5 and the insertion pipe vent valve 23, and finally the insertion pipe Ben I and valve 23 are fully closed.

After fully closing the insertion pipe vent valve 23, the pressure of the driving water is increased to approximately 10 kg/C#i by Tj, and the direction control valve 6a,
6b is excited for a few seconds and CRD2 is inserted by 1 to 2 notches.

After that, the pressure of the driving water is controlled again to about 3 Kg/ci, the directional control valves 6c and 6d are further excited, the driving water is flowed to the CRD 2 through the extraction pipe 4, and the CRD 2 is pulled out to the position before insertion. perform an action. Then, in this state, open and close the extraction pipe vent valve 24 several times to
IJ 5h+t and others perform air venting of the drawn piping pen 1-valve 24 bar, and finally fully open the drawn piping vent 1-valve 24.

Next, the driving water pressure is increased to about 10 to 9/ci, and the direction control valves 6a and 6b are excited for a few seconds to increase the driving water to CRD2.
drive screw] to the bottom surface of the ring 10, and insert the CRD 2 by about 1 to 2 notches. After this, the drawn pipe vent valve 24 is fully opened, and air is vented from the CRD 2 to the air vent 1 between the drawn pipe vent valve 24. Then pull out piping Ben 1 - Valve 2/
Let I be fully closed.

After fully opening the extraction piping pen 1 and valve 24, open the directional control valve 6.
Excite the screws c and 6d for a few seconds, and pour the driving water onto the driving screw 10-L surface of the CRD2,
CR+) Treats 2. At this time, the insertion pipe vent valve 23 is set as the entire test, and steps 1 to 1 between the CRD 2 and the insertion pipe vent valve 23 are performed.

Then, the driving water pressure horn was adjusted to 3 Kg, 1 cm from the culm degree.
0 to 9・ci culm turtle to intersection, and CRD 2 1~
Insertion of 2-knot J culm a and extraction of 1-2-knop culm a.
Repeat once, then perform F7 venting in the CRD 2 between all steps from the highest pulling position (for example, 718 position) to the lowest insertion position (00 position). In this case, at the same time, the insertion pipe 3 a3 J and the withdrawal pipe 4 connected to the CRD 2 are also subjected to the T aben 1~.

Note that when CRl) 2 is not driven, that is, when none of the directional control valves 6a to 6d are energized,
The driving water from the driving water pump 19 flows into the CRD 2 as cooling water from the cold IJI water piping 25 through the insertion piping 3, and leaks through gaps such as the seal ring of the CRD 2. It is flowing in little by little. However, this flow rate is 1 J/m per CRD2.
Since the air flow is very small, about in, it has almost no ability as an air vent. In addition, the code|symbol 26 shows a stabilization valve.

(Problems to be Solved by the Invention) Venting work for conventional control rod-driven hydraulic equipment requires a large amount of work time, and has a large impact on the construction period (process) of construction plans 1 to 1. In addition, in the case of operation plan 1~, the periodic inspection period has tended to be shortened in recent years, and this has become a major hindrance to shortening the periodic inspection period.

In addition, in the case of an operating plant, the total exposure HIi of all workers working within Plan 1 is managed, and if the Er-Avent process becomes longer, it is undesirable in terms of low total exposure.

Furthermore, during the air vent 1-J3 operation during the extraction operation that supplies driving water to the top surface of the drive screws 1-10 of the CRD2,
If the driving water pressure exceeds a certain value, the latch that secures the CRD2 will come off due to the driving water pressure, and in rare cases the CRD2 will be pulled out for its entire stroke.
There was a possibility that a problem called "CRD2 drop I" might occur. In particular, when the reactor core 8 is loaded with uranium fuel, the fall of the CRD 2, that is, the unplanned withdrawal of the control rod 7 from the reactor core 8, will rapidly increase the reactivity of the fuel, causing the fuel to deteriorate. There was a risk of severe thermal shock.

The present invention was made in consideration of the following two circumstances, and it is possible to shorten the air vent time, avoid reducing the amount of work Ω, and reduce the amount of work required to drive the control rod.
An object of the present invention is to provide a vent device for a control rod-driven hydraulic device that can prevent falling of eia IAs.

[Structure of the invention]

(Means for Solving Eight Problems) The present invention provides a drive water pump that supplies drive water for driving a control rod drive mechanism, a drive water pipe that guides drive water from the drive water pump, and a drive water pipe that guides the drive water from the drive water pump. A water pressure control unit that covers the control 1 supply of drive water guided by the drive water piping to the control rod drive mechanism, and this water pressure INI 11! A control rod drive hydraulic device comprising an insertion pipe that supplies drive water for one application from the unit 1- to the control rod drive mechanism, and a withdrawal pipe that supplies drive water for withdrawal from the hydraulic pressure unit 811 to the control rod drive mechanism. In the venting device of It is equipped with a pressure horn detection device that outputs a cutoff signal, and a pressure water cutoff valve that stops the supply of power water when the cutoff signal is input.

(Function) First, at the beginning of venting work, pressure water for venting is supplied from the pressure water supply system to all control rod drive mechanisms, and air bending is performed for a certain period of time. When the pressure of the pressure water in the pressure water supply system exceeds a set value during this work, the pressure detection device detects this and outputs a cutoff signal. The cutoff signal is input to the pressure water cutoff valve, which stops the supply of pressure water from the pressure water supply system to the control rod drive mechanism.

In this way, since air venting is performed by supplying red water to all control rod drive mechanisms at the beginning of venting work, it is possible to shorten the length of the venting process and reduce the amount of radiation exposure for workers. I can do it.

J: In addition, since the supply of pressure water is stopped when the pressure of the pressure water exceeds a set value, it is possible to prevent the control rod drive mechanism from falling.

(Example) An embodiment of the present invention will be described with reference to FIG.

In FIG. 1, the same parts as in FIG. 2 are given the same reference numerals, and detailed explanation will be omitted. A power water supply system 27 capable of supplying pressure water for L bending to all control rod drive II structures (hereinafter referred to as CRD) is installed in the vent device. The pressure water supply system 27 consists of a 4'' system indicated by the broken line in FIG. In other words, a pipe extending from the drive water pump 19 is connected to a connecting pipe 20, and a flow rate regulating valve 21 (FCV) is interposed in the connecting pipe 20. The communication pipe 20 is then connected to the driving water pipe 9 and also has a pressure regulating valve (
Cooling water piping 25 extends roughly with PC■) 22 interposed
connected to. A #1 water pipe 11 is connected to the cooling water pipe 25, and a dry water bypass pipe 2 is further connected to this drainage pipe 11.
8 is connected, and a drainage bypass valve 29 is interposed in this drainage bypass piping 28. For example, a solenoid valve is used as the JJI water bypass valve 29.

The end of the drainage bypass pipe 28 is connected to the drainage pipe 11, and the drainage pipe 11 is connected to the water pressure
) 5 directional control valve 6b. The directional control valve 6b is connected to the drawn pipe 4, and the end of the drawn pipe 4 is connected to the CRD.
Connected to the top of 2.

On the other hand, the drive water pipe 9 branched at the connection pipe 20 is connected to the HC (+5) direction control valve 6a via the drive water isolation valve 30.The direction control valve 6a is connected to the insertion pipe 3, and this insertion The end of pipe 3 is connected to the bottom of OR+) 2.

A vent pipe 31 is provided in the extraction pipe 4 of the pressure water supply system 27.
is connected to this vent pipe 31, and a pull-out pipe vent valve 3 is connected to the vent pipe 31.
2 is interposed, and a pressure detection device 34 that detects the pressure of pressure water in the pressure horn water supply system 27 and outputs a cutoff signal 33 when the detected value exceeds a set value is connected.

The cutoff signal 33 is input to a dead tree bypass valve 29 and a drive water isolation valve 30, which serve as pressure water cutoff valves that stop the supply of pressure water when the cutoff signal 33 is input.

This pen] When performing work on Ben 1~ with a device,
First, pressure water for venting is supplied to the CRD 2 from the pressure water supply system 27. In other words, the pressure water coming out of the drive water pump 11) passes through the connecting pipe 20 and is connected to the CV21 and PCV.
22 and from the drainage bypass pipe 28 to the directional control valve 6b.
, and is roughly supplied to the upper surface side of the driving screws 10 of the CRD 2 through the drawn piping 4. In this case, the drainage bypass valve 29 and the direction control valve 6b are open.

Moreover, the pressure water branched from the connection pipe 20 is connected to the drive water pipe 9,
The insertion pipe 3 passes through the driving water isolation valve 30 and is inserted from the direction control valve 6a.
It is supplied to the lower surface side of the drive screw 10 of the CRD 2 through the drive screw 10 of the CRD 2. In this case, the driving water isolation valve 30 and the J direction control valve 6a are open.

Pressure water FCV 21 a5 YoP CV 22 NiJ: It is controlled to about 3Kg/cti, and the total CR
D2 is kept under pressure all day and night (about 20 to 24 hours). During that time, all the drawn pipe vent valves 24 are opened and closed several times, and the drawn pipe vent valves 24 are opened and closed from the HCU 5 to the drawn pipe vent valve 1.
A round bend is performed mainly on the bowed piping 4 between the valves 24.

In addition, during this time, the CRD 2 is vented by continuously supplying pressure water to the CRD 2.

Similarly, open and close all the insertion pipe vent valves 23 several times, and
While air venting is performed mainly on the insertion pipe 3 between the CU 5 and the insertion pipe vent valve 23, air venting inside the CRD 2 is performed by supplying pressurized water to the CRD 2.

During this venting work, the drawn pipe vent valve 32 is always kept closed, and the pressure of the pressure water in the drawn pipe 4 is constantly monitored by the pressure detection device 34. If the pressure of the pressure water exceeds the set value for some reason, the pressure detection device 34 outputs a cutoff signal 33. Input this cutoff signal 33 to fC drainage bypass valve 29 and drive water isolation valve 30.
Close the valve and stop the supply of water to CRl) 2. CR[)2 is usually fixed to the wrap,
Although it is designed to prevent pages from falling out, if the pressure of the pressurized water to the CRD 2 exceeds a certain value, the latch may occasionally become loose due to the pressure of the pressurized water. In this case, CRD2[, 1Jζ will fall onto the own vehicle. However, when the pressure horn of the pressure water disappears, the wrap closes immediately, so the wrap of CRD2
Since the knob closest to the part at a certain point hits the lap, the fall of CRD2 stops there.In the wooden example, when the pressure of pressure water exceeds the set value, Since the supply is stopped, it is possible to prevent the CRD 2 from falling due to an increase in the pressure of the pressurized water.

This way 11-Power water supply system 27 to all CRD2 11
After supplying water and maintaining it for about 20 days, perform venting work on each CRI (CRI) 2 pipe in the same manner as before. In other words, using pressure water of about 10 kg/cM,
The operation of inserting 1 to 2 knobs of the CRD 2 by switching the opening and closing of the directional control valves 5a, 6b, 6c, and 3d;
Repeat the action of pulling out 1-2 notches several times. This C
By performing the venting work on CRD 2 (RI) 2 one by one, it is possible to completely air vent the CRD 2, J2, and the attached insertion piping 3 and extraction piping 4. In this case, although the venting work for each RD2 is simplified compared to the conventional method, all CRDs must be vented in advance.
Since the rough venting work has been carried out for No. 2, subsequent venting work can be carried out smoothly one by one.

In this way, if J: is applied to the above embodiment, the pressure water supply system 27
By supplying pressurized water to all CRD2s and performing venting work, the subsequent work time for air venting 1~ of CRD2 for each tree can be greatly shortened, and the work time of the construction plant culm and operation bran 1~ can be greatly reduced. This can greatly contribute to shortening the regular inspection period. Furthermore, since the pen mill operation time of CRD2 can be shortened, the cost of operation 0 can be reduced.

Furthermore, since it is possible to prevent the CRD 2 from falling due to the excessive pressure of the pressurized water, sudden unbowing of the control rods 7 in the reactor core 8 connected to the CRD 2 etc. can be prevented, and the large impact on the fuel can be prevented. Thermal shock can be prevented and the safety of the nuclear reactor can be ensured.

〔Effect of the invention〕

A vent device for a control rod drive hydraulic system according to the present invention includes a pressure water supply system capable of supplying pressure water for venting to all control rod drive mechanisms, and detects the pressure of the pressure water in the pressure water supply system. The pressure detection device outputs a cutoff signal when the detected value exceeds the set value, and the pressure water cutoff valve stops the supply of pressure water when the cutoff signal is received. By supplying pressurized water from the system to all control rod drive mechanisms to perform C venting, the air venting process can be significantly shortened and the amount of radiation exposure for workers can be reduced. Oh (-)
The safety of the reactor can be ensured by preventing the control rod drive mechanism from falling.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of a vent device for a control rod drive hydraulic device according to the present invention, and FIG. 2 is a configuration diagram showing a conventional vent device for a control rod drive hydraulic device. 2... Control rod drive mechanism, 3... Insertion piping, 4...
Bow handling piping, 5...Water pressure control unit 1~. 9... Drive water pipe, 11... Drain pipe, 19... Drive water pump, 20... Connection pipe, 21... Flow rate adjustment valve, 22...
...Pressure control valve, 23...Insertion piping vent valve, 24.
・・Pull-out piping vent valve, 25 ・・Cooling water piping, 27・
... Pressure water supply system, 29 ... Drainage bypass valve, 30
... Drive water isolation valve, 32 ... Pull-out piping vent valve, 3
3... Cutoff signal, 3/I... Pressure detection device.

Claims (1)

[Claims] A drive water pump that supplies drive water to drive the control rod drive mechanism, a drive water piping that guides the drive water from the drive water pump, and a control rod drive mechanism for the drive water that is guided by the drive water piping. an insertion pipe that supplies driving water for insertion from the hydraulic control unit to the control rod drive mechanism; and an extraction pipe that supplies driving water for withdrawal from the hydraulic control unit to the control rod drive mechanism. In a venting device for a control rod drive hydraulic system equipped with piping, a pressure water supply system capable of supplying pressurized water for venting to all control rod drive mechanisms, and detecting the pressure of the pressure water in the pressure water supply system. A control characterized by comprising a pressure detection device that outputs a cutoff signal when a detected value exceeds a set value, and a pressure water cutoff valve that stops the supply of pressure water when the cutoff signal is input. Venting device for rod-driven hydraulic equipment.