JPS6017394A - Driving device for 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 [Technical Field of the Invention] The present invention relates to a control rod drive device, and more particularly to an improvement in a control rod drive device that ensures rapid insertion of control rods into a nuclear reactor during scram of a nuclear reactor.

[Technical background of the invention and its problems]

FIG. 1 shows a control rod drive system installed in a conventional boiling water reactor. Reference numeral 1 in the figure is a nuclear reactor pressure vessel, which houses a reactor core 2 loaded with nuclear fuel material. The control rods 3 that are inserted into and withdrawn from the reactor core 2 are driven by a control rod drive mechanism 4. This control rod drive mechanism 4 is provided at the lower part of the reactor pressure vessel 1, and although only one unit is shown in FIG. 1 for convenience of explanation, there are multiple control rod drive mechanisms 4 that correspond to the number of installed control rods 3 and that are independent of each other. It is arranged to operate as follows. A control rod drive mechanism 4 connects a control rod 3 to a piston 5 that moves up and down in a cylinder.
and inject driving water into the lower chamber located below the piston 5 to raise the piston 5 and insert the control rod 3. On the other hand, driving water is injected into the upper chamber located above the piston 5. The control rod 3 is withdrawn by injecting it and lowering the piston 5. An insertion pipe 6 is connected to the lower chamber of the cylinder, and a withdrawal pipe 7 is connected to the upper chamber. The other end portions of these insertion and withdrawal pipes 6 and 7 pass through the side wall of the reactor containment vessel 8 that houses the reactor pressure vessel 1 and are connected to a hydraulic control unit 9 in the reactor shelter (not shown). Kono'Q pressure III unit) 9u
Condensate storage tank 1 via master control unit 10
1, and the condensate in the condensate storage tank 11 is used as control rod driving water (hereinafter referred to as driving water) through the master control 10, water pressure side 1-knit 9, etc. in sequence. It is designed to be supplied to the insertion and extraction pipes 6 and 7.

During an emergency reactor shutdown, the scram population valve 12 and scram outlet valve 13 of the water pressure control unit 9 are opened.

As a result, the high pressure water stored in the accumulator 14 is
Guided by the open scram valve 12, it is supplied to the lower chamber of the cylinder of the control rod drive mechanism 4 through the insertion pipe 6, causing the piston 5 to move upward and rapidly inserting the control rod 3 into the reactor core 2. .

At this time, the scram water in the upper chamber of the cylinder is guided to the opened scram outlet valve 13 and is discharged from the ladder 15 to scram discharge. In this way, at the time of reactor emergency shutdown (hereinafter referred to as reactor scram time), the scram population valve 12 and the scram outlet valve 13 are operated to supply or discharge scram water to the control rod drive mechanism 4 for control. Since the rod 3 is rapidly inserted, in the unlikely event that the scram population valve 12 and the scram outlet valve 13 become inoperable and are not opened, the supply of high pressure water (scram water) from the accumulator 14 or A situation arises in which scram water drainage is obstructed and rapid insertion of the control rod 3 is not possible.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and is a control rod capable of reliably and rapidly inserting the control rod 3 even if the scram artificial valve or the scram outlet valve incorporated in the hydraulic control unit malfunctions. The purpose is to provide a driving device.

[Summary of the invention]

In order to achieve the above-mentioned object, a control rod drive device according to the present invention is configured as follows.

A scram water supply pipe that supplies scram water to the control rod drive mechanism is equipped with a scram population valve, and a scram ice discharge pipe that drains scram water from the control rod drive mechanism is equipped with a scram outlet valve.It is equipped with multiple water pressure control units. In the control rod drive device, a scram water supply communication pipe that connects the scram water supply pipe of the water pressure control unit and the scram water supply pipe of the other water pressure control unit on the downstream side of these scram population valves; a scram water discharge communication pipe that communicates the scram water discharge pipe of the water pressure control unit with the scram water discharge pipe of the other water pressure control unit on the upstream side of these scram outlet valves; The system includes a scram water supply communication pipe and an on-off valve interposed in each of the scram water supply communication pipes.

[Embodiments of the invention]

An embodiment of the control rod drive device according to the present invention will be described below with reference to FIG. 2.

FIG. 2 is a system diagram showing the configuration of the control salary 1 drive device according to an embodiment of the present invention, and for convenience of explanation, only two water pressure control units 9, 9a and 9b, are shown. As described above, a plurality of hydraulic control units 9 are provided corresponding to the number of installed control rods 3 and control rod drive mechanisms 4, and are arranged so as to operate independently of each other. That is, the other ends of the insertion pipe 6a and the withdrawal pipe 7b connected to one control rod drive mechanism, for example 4a, are connected to one hydraulic control unit) 9a. This control unit) 9a, together with other water pressure control units) 9b, etc., connects the master control unit 10, control rod drive water pump B, etc. via a drive water header, a scram water distribution header 21, and a cooling water header η. They are sequentially connected to a condensate storage tank 11.

Thereby, the condensate stored in the condensate storage tank 11 is supplied to each hydraulic control unit F 9 a , '9 b + . . . as drive water, scram water, and cooling water.

The water pressure control units) 9a, 9b, . . . have scram water supply piping 24a, 24b, . . . and scram water discharge piping 25a, 25b, . One end of these scram water supply pipes 24a, 24b... is connected to each insertion pipe 6'.
a, 5b, while the other end is the scram water distribution header 2
Accumulators 14a, 14b, . . . , which store high-pressure water, are connected to a part of the scram water supply pipes 24a, 24b.

... and the insertion pipe 5a16b+... Furthermore, these accumulators 14a, 14
b.

On the downstream side of the connection with..., there is a scram valve 12a.
.

12b, . . . are interposed respectively. On the other hand, one end of the scram water discharge pipes 25a, 25b... is connected to each pullout pipe 7a, 7b...
The ends are connected to the scram drainage header 15 after intervening scram outlet valves 13a + t3b, respectively, and the scram water in the control rod drive mechanism, e.g. It is designed so that it can be discharged completely. Water pressure control unit 9a.

Directional control valves 26 a + 26 b provided in 9b...
... are connected at one end to each insertion pipe 6a, 6b... and withdrawal pipe 7a, 7b..., and at the other end to the drive water header addition and discharge ladder 27, respectively. When withdrawing the control rod 3, the direction control valves 26a, 26b, . control. Also, this switching control simultaneously switches the insertion piping 6 av 6 b... and the piping of the discharge header n so that the driving water flows into the cylinder upper chamber of the control rod drive mechanism 4 via the extraction piping 7a. At the same time, the driving water in the lower chamber of the cylinder is supplied to the insertion pipe 6.
It is discharged from the ladder n to the discharge via a*6 b... For this reason, the piston 5 of the control rod drive mechanism 4 is pushed down, and the control rod 3 is lowered and withdrawn.

In addition, the water pressure control units) 9a, 9b, . . . have cooling water pipes 28a, 28b, .
a.

One end of 28b... is inserted into the insertion pipes 6a, 6b...
The other ends are each connected to a portion of the ladder 22 to cool water. This cooling water ladder 22 is connected to a condensate storage tank 11 via a master control unit 10 etc., and the condensate in this tank 11 is supplied to the master control unit 1.
The water is guided to the cooling water header n via a flow rate adjustment valve 29 and a pressure adjustment valve (g). Therefore, the cooling water supplied to the cooling water header 22 is branched to each water pressure control unit) 9a, 9b, etc., and is guided to the insertion pipe 6a via the cooling water pipe 28a of the required water pressure control unit, for example, 9a. Ru.

The insertion pipe 6a communicates with a lower chamber located below the piston 5 of the cylinder of the control rod drive mechanism 4a, so when driving water is supplied to this lower chamber, the piston 5 rises.
A control rod 3 connected to this piston 5 is inserted into the reactor core 2 .

By the way, the scram water supply pipe 24a of one water pressure control unit) 9a is connected to the scram water supply pipe 24b of the other water pressure control unit 9b with both scram water inlet valves 12a.
, 12b are connected so as to communicate with each other by a scram water supply communication pipe 31 on the downstream side, and a remote control valve 3 for scram water supply is installed in the middle of this scram water supply communication pipe 31.
2 is interposed.

Further, the scram water discharge pipe 25a of one water pressure control unit 9a is connected to the scram water discharge pipe 25b of the other water pressure control unit 9b, and both scram water outlet valves 13a, 1
3b are connected to communicate with each other by a scram water discharge communication pipe 33, and a remote control valve 34 for scram water discharge is interposed in the middle of this scram water discharge communication pipe. In this way, the rainwater pressure control unit 9 a +
Both scram water supply piping 24 of 9b. a, 24
b and both scram water discharge pipes 25 a + 25 b are connected to each other so as to communicate with each other. Therefore, even if one of the water pressure control units, for example, the scram population valve 12a of 9a, becomes inoperable due to a malfunction or the like and an accident occurs in which the valve is not opened, the scram valve 12a of the other water pressure control unit 9a will be supplied with scram water via the scram water supply communication pipe 31. Water is provided.

Similarly, even if the scram outlet valve 13a of one water pressure control unit 9a fails and is not opened, scram water is discharged from the ladder 15 to the scram discharge by the other water pressure control unit 9b via the scram water discharge communication pipe 33. be discharged.

Next, the operation of the above-mentioned embodiment will be described at the time of reactor scram.

Each hydraulic control unit 9a + 9b is installed so that most of the control rods 3 are rapidly inserted into the reactor core 2 during a reactor scram.
The scram population valves 12a, 12b,... and the scram outlet valves i3a+13b,... are opened.

When the scram population valves 12a, 12b, . . . are opened, high-pressure scram water is supplied from the accumulators 14a, 14b +, .
,... to the insertion pipes 6a, 5b,..., and are guided to the lower side of the piston 5a... of each control rod drive mechanism 4a... by the insertion pipes 6a, 5b,... Scram water is supplied to the lower chamber of the cylinder where it is located, and pushes the pistons 5a+ upward. At the same time, the scram water in the upper chamber of the cylinder located above the piston 5a sequentially passes through the extraction pipes 7a, 7b, . . . , the scram water discharge pipe 25a, and the scram water outlet valve 13 which is opened a + 13 b... and are respectively discharged from the ladder 15 to the scram discharge. As a result, each of the pistons 5a, . . . rises upward,
Each control rod 3 connected to this piston 5a is rapidly inserted. And the scram water large mouth valve 12a.

12b, ... and scram water outlet valve 13at13b
, . . . simultaneously with the opening of the scram water supply remote control valve 32 and the scram water discharge remote control valve 32. Therefore, in the unlikely event that the scram population valve 12a.

12b, ... or scram exit valve 13a+13b
Even if y... is inoperable due to a malfunction or the like and is not opened, it is guided by the scram water supply communication pipe 31 and the scram water discharge communication pipe 33 to other water pressure control units,
For example, scram water is supplied from 9b to the insertion pipe 6a of one water pressure control unit 9a.

In addition, by other water pressure control unit 9b etc., the extraction piping 7
The scram water in a+7b... is scram discharge header 1
It is discharged from 5. For this reason, in the unlikely event that Scrum population valve 1
2a + 1.2b +...or even if one or both of the scram outlet valves 13a, 13b... are inoperable due to a failure etc. and are not opened, the scram water supply communication pipe 31, its scram water supply remote control valve 32, and scram water discharge communication pipe 33
The scram water is supplied to each control rod drive mechanism 4 or is discharged from the scram discharge header 15 guided by the remote control valve 34 for scram water discharge. Thereby, each control rod 3 can be rapidly inserted into the reactor core 2 without any hindrance.

In the above-described embodiment, two hydraulic control units are communicated with each other as shown in FIG. 2, but the control rod drive device according to the present invention is of course not limited to the number of hydraulic control units that are communicated with each other.

〔Effect of the invention〕

As described above, the control rod according to the present invention, #, T: JTh
In the apparatus, the scram water supply piping and scram water discharge piping of one water pressure control unit are connected to the scram water supply piping and scram water discharge piping of the other water pressure control unit, respectively. Therefore, even if one or both of the scram water outlet valve or scram water outlet valve of one water pressure control unit malfunctions and becomes inoperable, the other water pressure control unit will scram water can be supplied to the water pressure control unit. At the same time, the scram water from one water pressure control unit can be discharged by the other water pressure control unit, so each control rod can be rapidly inserted reliably and smoothly during reactor scram. Thereby, the safety and soundness of the nuclear reactor can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a partial system diagram of a conventional control rod drive device, and FIG. 2 is a partial system diagram showing an embodiment of the control rod drive device according to the present invention. 1... Nuclear reactor, 2... Reactor core, 3... Control rod, 4...
... Control rod drive mechanism, 5... Piston, 6... Insertion piping, 7... Pulling out piping, 9... Water pressure control unit,
IO...Master 7 control section, Ll...Condensate storage tank, 12...Scram water outlet valve, 13...
Scram water outlet valve, 14...accumulator, 24
a + 24 b...Scram water supply piping, 25a,
25b... Scram water discharge pipe, 31... Scram water supply communication pipe, 32... Remote control valve for scram water supply, 33... Scram water discharge communication pipe, 34... Remote for scram water discharge Operation valve. Applicant's agent Hatano

Claims (1)

[Claims] 1. A scram water supply pipe that supplies scram water to the control rod drive mechanism is provided with a scram water supply valve, and a scram water discharge pipe that drains scram water from the control rod drive mechanism is provided with a scram outlet valve. In a control rod drive device equipped with a plurality of water pressure control units, a scram water supply pipe for communicating the scram water supply pipe of the water pressure control unit with the scram water supply pipe of another water pressure control unit downstream of these scram population valves. A scram water discharge communication pipe that connects the water supply communication pipe, the scram water discharge pipe of the water pressure control unit, and the scram water discharge pipe of the other hydraulic control unit on the upstream side of these scram exit valves; A control rod drive device characterized by having on-off valves interposed in the scram water discharge communication pipe and the scram water supply communication pipe, respectively. 2. The control rod drive device according to claim 1, wherein the scram water supply pipe is connected to an accumulator that stores high-pressure water on the downstream side of the scram artificial valve. 3. The control rod drive device according to claim 41, wherein the scram water supply pipe is connected to a drive water supply pipe that supplies control rod drive water. 4. The control rod drive device according to claim 1, wherein the scram water discharge piping is connected to a scram discharge header for discharging scram water downstream of the scram outlet valve. 5. The control rod drive device according to claim 1, wherein the on-off valves respectively installed in the scram water discharge communication pipe and the scram water supply communication pipe are remote control valves.