JPS62247286A - Air feeder for operating scram valve - 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] [Object of the Invention] (Industrial Application Field) The present invention is directed to a boiling water reactor (hereinafter referred to as BWR).
We will work on improving the air supply device for operating the scram valve of the ltll rod drive system.

(Prior Art) A conventional example will be explained with reference to FIG. Figure 2 shows the conventional scram valve operating air supply vAr! 1 in the diagram showing the configuration of 1
Reference numeral 1 in the figure indicates a reactor pressure vessel.

Inside this reactor pressure vessel 1, a cold wrought material 2 and a reactor core 3 are installed. This core 3 is composed of a plurality of fuel assemblies (not shown), control rods 4 (only one is shown in the figure), and the like. The control rod 4 is controlled by a control rod drive mechanism 5. In other words, the clamp drive 11445 is the housing 5.
a and a piston 5b housed in the housing 5a so as to be able to move up and down, and the dovetail 4 described above is connected to the piston 5b. Further, a control rod insertion pipe 6 is connected to the lower surface of the piston 5b, and a control rod car floor pipe 7 is connected to the upper surface. A scram artificial valve 8 is inserted into the control rod insertion pipe 6, and a scram water supply device 9 is connected thereto. On the other hand, a scram outlet valve 10 is inserted into the control pipe 7. Therefore, when the reactor is to be brought to an emergency shutdown (hereinafter referred to as scram), the scram population valve 8 and the scram outlet valve 10 are closed to allow scram water to act on the lower surface side of the screw I/N 5b. As a result, the piston 5b rises rapidly and the control rod 4 is urgently inserted into the reactor core 3. - Shoplifting water is temporarily stored in the scram discharge container 11 via the withdrawal piping 7, and then at the time of reset, the scram drain valve 1
2 and the scram bend valve 13 are opened and discharged.

In the above configuration, the scram population valve 8 and the scram outlet valve 1
0, scram drain valve 12 and scram bend valve 13
The scram valve operating air supply device supplies operating air to the scram valve. To explain below, first, reference numeral 21 in the figure is an air pipe connected to an instrumentation air compressor (not shown), and a filter 22 is inserted into this air pipe 21, followed by a pressure regulating valve 23, an on-off valve, etc. 24, a backup scram pylon l-valve 25, 26 and an on-off valve 27 are inserted. Furthermore, a hook 28 to the air is connected to the tip. Note that a check valve 29 is provided in parallel with the valve 26 to the rear scram drain valve 1. A plurality of branch air pipes 30 are branched from the header 28, each corresponding to a plurality of control rod drive systems. In the diagram, one of them
Only one part is shown. That is, the branch air piping 30
An on-off valve 31 is inserted into the scram pilot valve 32, and the scram pilot valve 32 is connected to the operating parts of the scram population valve 8 and the scram outlet valve 10 via the scram pilot valve 32.

On the other hand, another air pipe 33 is branched from between the backup scram pilot valve 26 and the on-off valve 27, and a scram drain/vent pilot valve 34 is connected to this air pipe 33. The operating parts of the scram drain valve 12 and the scram bend valve 13 are connected to the pilot valve 34 .

According to the above configuration, during scram, air is discharged from the scram pilot valve 32 to open the scram population valve 8 and the scram outlet valve 10. As a result, scram water is supplied from the scram water supply device 9 to the lower surface side of the piston 5b via the scram inlet valve 8, and thereby the control rods 4 are urgently inserted into the reactor core 3. On the other hand, the waste water is drained through the control rod pulling bed pipe 7 and the scram outlet valve 10 and stored in the scram discharge container 11.

Next, when restarting the reactor, the scram reset signal 841 is output, the scram byron l-valve 32 and the scram drain pend byron I-valve 34 are switched, and the scram population valve 8 and the scram outlet valve 10 are closed. At the same time, the scram drain valve 12j3 and the scram bend valve 13 are opened. As a result, the scram operation ends and the waste water stored in the scram discharge container 11 is discharged to a drain sump (not shown).

The above configuration has the following problems.

That is, the scram reset signal is sent to the scram pilot valve 32 via the pressure regulating valve 23 etc. and the air header 28.
However, the scram pilot valve 32 will not operate unless there is a certain pressure. By the way, as mentioned above, a plurality of scram pilot valves 32 are installed (for example, over a hundred), and in the event that a leak occurs in some of these scram drain valves 32, , the pressure in the air header 28 will not increase. If the pressure in the air header 28 does not rise, the scram byron 1 to the valve 32 will not return to normal operation, resulting in a situation where air continues to be discharged. Furthermore, in that case, the scram population valve 8 and the scram outlet valve 10 cannot be closed, and the scram drain valve 12 and the scram bend valve 13 also remain open, and as a result, reactor water flows into the usage piping 7 and the scram outlet valve. 10,
It is also expected that the scram will continue to be discharged into the drain sump via the scram discharge container 11.

(Problem to be Solved by the Invention) As described above, in the conventional air supply device for operating the scram valve, when a leak occurs in the scram by-lower 1 to the valve, the pressure in the air header is not normal. As a result, the scram pilot valve, or even the scram valve, does not operate normally, resulting in various malfunctions.The present invention was made based on this problem. The purpose of this is to ensure that even if a leak occurs in the scram pilot valve, it will operate normally and provide healthy operation of the scram valve and, by extension, normal operation of the control rod drive system. An object of the present invention is to provide an air supply device for operating a scram valve.

[Structure of the Invention] (Means for Solving the Problems) In other words, the scram valve operating air supply device according to the present invention supplies air from an instrumentation air compressor to the scram pilot valve via an air pipe. A scram valve operating air supply device that controls the opening and closing of various scram valves by operating this scram pilot valve includes a pressure cowl that is attached to the air piping and outputs a signal at a preset pressure, and this pressure switch. The present invention is characterized in that it is provided with an auxiliary air supply 〇M groove for supplying air to the air piping via another air piping in response to a signal from the air piping.

(Function) In other words, if the pressure of the air header does not rise to a predetermined value at the time of scram reset, air is supplied from the auxiliary air supply 1 to increase the pressure of the air header, thereby providing normal operation. It is something that

(Example) An example of the present invention will be described below with reference to FIG. It should be noted that the same parts as in the prior art are denoted by the same reference numerals and the explanation thereof will be omitted. Another air pipe 101 is connected to the air pipe 21. Air is also supplied to this air pipe 101 from an instrumentation air compressor 1 (not shown). A solenoid valve 102, a filter 103, a pressure regulating valve 104, and an on-off valve 105 are inserted into this air pipe 101.

Further, an exhaust solenoid valve 106 is branched and connected between the solenoid valve 102 and the filter 103.

On the other hand, a pressure switch 107 is installed near the air header 28 of the air pipe 21. The signal from this pressure switch 107 is transmitted to the open/close switch 108 and the timer 1.
09 to the electromagnetic valve 102. In other words, if the pressure in the air header 28 does not rise to a predetermined value even after a certain period of time has passed after the scram reset signal @S41 is output, the solenoid valve 102 is opened and the air supply piping 101 is opened.
In order to increase the pressure in the air header 28, air is supplied through the air header 28.

The operation will be explained based on the above configuration. First, the set points of the pressure switch 107 are set to 9/car2 from 1 to 3. Further, the timer 108 is set to about 1 to 20 seconds. When the scram reset signal 841 is output, the open/close switch 107 closes and the pressure switch 107 and timer 10
9 is connected.

If the pressure in the air header 28 is 1 to 3 Kg/ctn2 even after a predetermined period of time has passed after the scram reset, the TS magnetic piece 02 opens. As a result, air is supplied to the air header 28 via the air piping 101, and as a result, the pressure inside the air header 28 increases to exceed the minimum operating pressure of the scram pilot valve 32, causing the scram pilot valve 32 to operate. . This reliably prevents the scram population valve 8 and the scram outlet valve 10 from closing and leaking reactor water.

Next, a case will be described in which the scram signal S42 is output for some reason when the electromagnetic valve 102 is opened and air is being supplied.

In this case, the output of the scram signal 842 causes the exhaust N magnetic piece 105 to open. As a result, the air is exhausted, ensuring that the pressure in the air header 28 drops to atmospheric pressure. Therefore, the scram population valve 8 and the scram outlet valve 10 are opened to enable scram operation.

According to this embodiment, the following effects can be achieved.

(1) First, even if the air pressure does not rise to a predetermined value using only the conventional air supply line, this is detected via the pressure switch 107 and the solenoid valve 102
By opening the valve, air can be supplied through the air pipe 101 and the pressure can be raised to a predetermined pressure.

Therefore, not only the scram drain valves 32 and 34 but also each of the scram valves 8, 10, 12, and 13 can be operated normally, and leakage of reactor water can be reliably prevented.

(2) Further, when air is being supplied by the new air piping 101 according to this embodiment, the scram signal S42
Even if the exhaust solenoid valve 10
Since the structure is such that air is exhausted by opening the valve 5, scram operation can be performed.

"Effects of the Invention" As detailed above, according to the air supply device for operating a scram valve according to the present invention, the pressure in the air piping is monitored by a pressure switch, and if the pressure does not rise to a predetermined level at the time of scram reset, for example, Since air is supplied by an auxiliary air supply mechanism, the scram pilot valve and even the scram valve can be operated reliably, greatly improving reliability. Situations such as leaks can be reliably avoided.

[Brief Description of the Drawings] Fig. 1 is a diagram showing the configuration of an air supply device for operating a scram valve according to an embodiment of the present invention, and Fig. 2 is a diagram showing the configuration of an air supply device for operating a scram valve according to a conventional example. It is. 8... Scrum population valve, 10... Scrum outlet valve,
12... Scram drain valve, 13... Scram bend valve, 21... Air piping, 28... Air header,
32゜34... Pilot valve, 101... Air piping, 102... 1st valve, 107... Pressure switch.

Claims (2)

[Claims] (1) In a scram valve operating air supply device that supplies air from an instrumentation air compressor to a scram pilot valve via an air pipe and controls the opening and closing of various scram valves by operating this scram pilot valve, A pressure switch that is attached to the air piping and outputs a signal at a preset pressure, and an auxiliary air supply mechanism that supplies air to the air piping via another air piping based on the signal from the pressure switch. An air supply device for operating a scram valve, characterized by: (2) The scram valve according to claim 1, wherein the auxiliary air supply mechanism is provided with an exhaust solenoid valve, and the exhaust solenoid valve is opened by outputting a scram signal. Operating air supply device.