JPH0444710B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a control rod motion measuring device for a nuclear reactor, and particularly to a control rod motion measuring device suitable for measuring the motion of high-speed scram type control rods.

[Prior art]

FIG. 1 is a schematic diagram of a control rod drive mechanism of a nuclear reactor, and a control rod 2 is inserted into or withdrawn from a nuclear reactor 1 by a drive piston 4 in a control rod drive mechanism 3. FIG. A magnet 7 is attached to the drive piston 4. When the drive piston 4 moves up and down, the magnet 7 opens and closes the reed switches 6 arranged and installed vertically in the position detector tube 5, and outputs a reed switch signal 100. This signal 100 is taken into the control rod position indicating system panel 10, where the closed reed switch is detected by the magnet 7, thereby detecting the insertion position of the control rod. In addition, in case of an emergency, the control rod 2
An action of quickly inserting the control rod 2 into the reactor, ie, a scram, is performed, but at this time, the rapidly inserted control rod 2 is decelerated by the buffer mechanism at the fully inserted position and comes to a stop. In particular, for high-speed scram type control rods, in order to confirm the soundness of the buffer mechanism of the control rod drive mechanism 3 during scram, it is necessary to measure the passage time of the reed switch at all insertion positions (referred to as buffer time). , which is also measured by the position indicating system panel 10.

FIG. 2 is a block diagram showing a more detailed configuration of the conventional position indicating system panel 10 for measuring the state of the control rods as described above. The arrangement is shown in FIG. However, in FIG. 3, symbols R00 to R53 are used to distinguish the reed switches 6, and among these, reed switch R53 is used in the embodiment of the present invention, and is not present in the conventional device. do. These reed switches R00 to R52
As shown in FIG. 4, these constitute the contacts of a 6×5 switch matrix, and the terminals V1 to V32 and H1 to H16 of this switch matrix are
The reed switch signal 100 shown in FIG. 2 is input to the detection section 12 of the control rod position indicating system panel 10. Therefore, the even numbered reed switch R00~
When any one of R48 (the symbol R is omitted in FIG. 4) is turned on by the magnet 7 in FIG. 1, one of the terminals V2 to V32 and the terminals H1 to H are turned on.
Since one of the control rods 16 is connected, its state is detected by the detection unit 12, converted into a signal 200 indicating the position of the control rod by the signal processing unit 11, and displayed by the control rod position indicator 20. . That is, reed switches R00 to R48 are used to detect the current position of the control rod.

On the other hand, odd numbered reed switches R01 to R47
and all others are connected to terminal V1 in Figure 4,
A connection is made between one of the terminals H1 to H16,
All of the reed switches R01 to R47 are connected in parallel, and when one of them is turned on, the terminal V
1 and H2 is turned on, which is detected by the odd numbered switch detection circuit 13 and taken in as an odd numbered read switch signal 300 by the control rod scram operation time measuring device 30. The measuring device 30 receives a signal 30
It is used to measure the on/off time of each reed switch R01 to R47 from 0 to 0, and to measure the operation time of the control rod 2 during scram (insertion) and withdrawal.

Furthermore, the reed switch R49 is in the on state indicating the fully withdrawn position of the control rod 2, the reed switch 50 is in the on state indicating the excessively withdrawn position, and the reed switches 51 and 52 are indicative of the fully inserted position (one reed switch (because the entire range of all insertion positions cannot be detected), the on state of each terminal V1
The signal processing circuit 11 detects the connection between the terminal H1, H8, H16, and H4, and displays the state on the display 20.

The buffer time required for high-speed scram type control rods, that is, the time when the control rods are fully inserted, is determined by the detection circuit 14 in FIG.
Reed switch R indicating all insertion positions from 0
51 is turned on, and outputs a signal 301 to the buffer time measuring recorder 40, thereby measuring the buffer time.

By the way, the control rod operation measuring system as described above requires a circuit as shown in FIG. 2 for each control rod. However, a 1.1 million kW class nuclear reactor has 185 control rods, so the overall amount of hardware becomes extremely large, making it complex and expensive.

[Purpose of the invention]

The present invention has been made in view of the problems of the prior art described above, and its purpose is to measure the buffer time of a high-speed scram type control rod drive mechanism with as little hardware as possible. The purpose of this invention is to provide a measuring device.

[Summary of the invention]

The above purpose is to provide a first reed switch group for detecting whether the control rod is in a fully withdrawn position, a fully inserted position, or a plurality of intermediate positions, and to turn the first reed switch group on and off. Processing and display means that determines and displays the current position of the control rod by inputting the state, and a device that turns on when the control rod passes one of a plurality of intermediate positions during movement, and whose contacts are all connected in parallel. A second reed switch group for detecting movement time, which is different from the first reed switch group, and a time when an ON signal is generated from the second reed switch group are used to detect the control rod. In a control rod operation measuring device equipped with a time measuring means for detecting a movement state, a contact point of the control rod is turned on when the control rod reaches the fully inserted position, and the contact point is connected to the second reed switch group. A reed switch is provided that is connected in parallel with each contact point of the reed switch, and the buffer time, which is the time when the control rod reaches the fully inserted position from the time it is turned on, is measured by the time measuring means. And it will be achieved.

[Embodiments of the invention]

An embodiment of the present invention will be described below. First, the arrangement of the reed switches 6 inside the position detector tube 5 is as shown in FIG. 3 used to explain the conventional example.
A reed switch R53 is added in the present invention.
This is installed at a position where it is turned on at the same time as reed switch R51. Reed switch R
A switch matrix containing 53 contacts is shown in Figure 5, with the contacts of the newly added reed switch R53 connected in parallel with those of odd numbers, and the contacts of reed switch R51 connected in parallel with those of reed switch R52. The only difference from the conventional Fig. 4 is that it is connected to the . Corresponding to the arrangement of these reed switches and the connection of the switch matrix, the processing system shown in FIG. 6 is used in place of the conventional processing system shown in FIG. 2. That is, the buffer time measuring recorder 40 is deleted.

The reason and operation of this embodiment are as follows. Since the reed switches R51 and R52 are originally intended to detect the fully inserted state of the control rod, their contacts should be connected in parallel as shown in FIG. 5 of this embodiment. In order to use R51 also for buffer time measurement, these were separated and incorporated into a switch matrix as shown in FIG. On the other hand, from the perspective of time measurement, both the conventional scram operation time measuring device 30 and the buffer time measuring recorder 40 described in FIG. 2 measure the ON time of one of the switches. , reed switch R51
If they were connected in parallel with the odd-numbered switches R01 to R47, it would be impossible to detect all insertions, so these were also separated, and for this reason, it was necessary to measure time using separate devices 30 and 40. This operation is shown in FIG. 7, taking as an example the case where the control rod 2 is moved from the fully withdrawn state to the fully inserted state. As shown in the figure, the odd reed switch signal 300 is connected to the reed switches R47, 4.
5, . Further, turning on the reed switch R51 is detected as a signal 301, which is measured by the buffer time measuring recorder 40 shown in FIG.

However, as in this embodiment, if a reed switch R53 for buffer time measurement is separately provided and the reed switch R51 is used only for the original full insertion detection, the contact position as shown in FIG. 5 becomes possible. That is, the reed switches R51 and R2 can be connected in parallel to output all inserted signals under OR conditions, and the OR logic of the reed switches R51 and R52 in the signal processing circuit 11 is therefore unnecessary, simplifying the structure. Become. In addition, the reed switch R53 can be connected in parallel with the odd-numbered reed switches R01 to R47, and therefore the buffer time can be measured using the scram operation time measuring device 30 that measures the ON time of the odd-numbered reed switches, and the buffer time can be measured using the conventional buffer time measurement record. A total of 40 will be unnecessary. That is, the terminal V1 in FIG.
The output signal 302 of the odd-numbered switch detection circuit (Fig. 6) 13 that detects the connection state between H2 becomes as shown in Fig. 8 when the control rod is moved from fully withdrawn to fully inserted. It also includes the ON signal of reed switch R53 when the position is reached. Therefore, using only the scram time measuring device 30, it is possible to measure the ON time of the reed switch R53 indicating the buffer time as well as the odd numbered reed switches R47-01. Moreover, if the measurement processing in the scrum time measurement device 30 is implemented using a microcomputer or the like, it can be handled by a simple modification of the software.

〔Effect of the invention〕

As is clear from the above embodiments, according to the device of the present invention, by adding one reed switch to each control rod, the circuit for measuring the buffer time can be significantly reduced. , a large economic effect can be obtained.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the control rod drive mechanism, Figure 2 is a block diagram of a conventional control rod operation measurement system, Figure 3 is a reed switch installation layout, and Figure 4 is a diagram of the reed in a conventional measurement system. 5 is a wiring diagram of the reed switch according to the present invention, FIG. 6 is a diagram showing an embodiment of the signal processing section of the measuring device of the present invention, and FIGS. 7 and 8 are conventional and FIG. 3 is an explanatory diagram of a time measurement signal during scram in the device of the present invention. DESCRIPTION OF SYMBOLS 1... Nuclear reactor, 2... Control rod, 3... Control rod drive mechanism, 4... Drive piston, 5... Position detector tube, 6... Reed switch, 7... Magnet,
10...Control rod position indication system panel, 11...Signal processing section, 12...Detection section, 13, 14...Detection circuit,
20... Control rod position indicator, 30... Control rod scram operation time measuring device, R00 to R53... Reed switch.

Claims (1)

[Claims] 1. A first reed switch group for detecting whether the control rod is in the fully withdrawn position, fully inserted position, or multiple intermediate positions, and the off-on state of the first reed switch group as input. processing and display means for determining and displaying the current position of the control rod; A second reed switch group for detecting movement time, which is different from the first reed switch group, and the movement state of the control rod is detected by measuring the generation time of an on signal from the second reed switch group. In the control rod operation measuring device, the contact is turned on when the control rod reaches the fully inserted position, and the contact is parallel to each contact of the second reed switch group. The invention is characterized in that a reed switch is connected to the reed switch, and the buffer time, which is the time when the control rod reaches the fully inserted position from the time it is turned on, is measured by the time measuring means. Control rod movement measuring device.