JPS62118299A - Position indicator 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 position indicating device that detects and displays the position of a control rod used for adjusting the reactor output in a nuclear power plant.

[Technical background of the invention and its problems] For example, in a boiling water nuclear power plant, usually several dozen to over a hundred control rods are incorporated into the reactor core, depending on the scale of the plant. The reactor is started by inserting and withdrawing these control rods.

The system is being stopped and operating conditions are being adjusted. The entire control mechanism is as shown in FIG. 2, and a control rod drive mechanism 3 for physically driving the control rods 2 inside the reactor vessel 1.
and a control rod drive device 5 which gives control rod insertion/extraction commands 4 to the control rod drive mechanism 3. A control rod position indicating device 81 receives control rod position information 6 from the control rod drive mechanism 3, stores the position of the entire control rod, and outputs position change information 7. Receives position change information 7 and determines whether it is valid or not. However, in the unlikely event that a control rod operation is performed that does not follow the prescribed procedure, the process computer 10 outputs a block signal 9 to the control rod drive device 5. Note that FIG. 2 shows only the main signal flows.

In order to operate a nuclear reactor in a sound manner, control rods must be operated according to established procedures.

The control mechanism to ensure this is the configuration shown in Figure 2.
Even if a control rod operation request 11 that does not follow the procedure is given to the control rod drive device 5, it has a function to automatically block it.

One basic condition for this function to be sufficient is a control rod position indicating device! ! 8 and process calculator 10
It is necessary that the response is sufficiently fast, and that a block signal can be output within at least one notch drive time of the control rod.

Conventionally, the control rod position indicating device 8 has performed position detection by sequentially scanning and capturing the position state of each control rod. Therefore, in order to determine the positions of all the control rods, it is necessary to wait until the scanning of all the control rods is completed, which takes a detection time of several tens of orders of magnitude depending on the scale of the plant. Actually, even if we look at the control rod while it is being driven, the position of the control rod is I! ! The position detection function of the pointing device 8 will not be affected, and detection of position changes will be delayed. Therefore.

The process computer 10 has to perform processing based on this detection overhead time, which imposes restrictions on the allowable processing time. Furthermore, since the detection delay in the conventional method is on the order of tens of milliseconds, the position change information 7 from the control rod position indicating device 8 can be used to measure and evaluate the operating speed of the control rod drive mechanism 3. was becoming difficult.

[Objective of the Invention] An object of the present invention is to detect the positional change of the control rod during driving at high speed, to shorten the response time of the blocking mechanism, and to avoid interfering with the update cycle of position information when not driving. and that this high-speed detection function allows the control rod position indicating device to be used to measure the drive speed of the control rod.

[Summary of the Invention] The present invention divides the scanning of control rod position information into control rods selectively driven by a control rod drive device and all other control rods. The former, that is, a control rod that is selectively driven;
The latter, that is, all other control rods are switched every scan to scan their position information alternately.

[Embodiment of the Invention] FIG. 1 shows a block diagram of an embodiment of the control rod position indicating device of the present invention. The control rod position indicating device of the present invention shown within the broken line in FIG. Control rod interface circuit 14 transmitting as control rod position signal 13
, the switching of the scan control rod is controlled based on the drive command signal 15, and the clock signal 16. A control circuit 18 that outputs a switching signal 17, a counter 20 that is incremented by the clock signal 16 and outputs a control rod scan address 19, and a control rod selection drive signal 21 that receives a control rod selection drive signal 21 from a control rod drive device and controls the control rod. The drive control rod address reception interface 23 converts address data 22 and drive command signal 15, and receives the scan address 19 and control rod address data 22. Switches this by a switching signal 17, and outputs address 2.
4, a transmission interface 26 that converts the address output 24 into a scan signal 12 which is a transmission signal and sends it, and a receiver that receives the control rod position signal 13 and converts it into control rod position data 27. The interface 28 and the control rod address in the control rod position data 27 are extracted and stored in the memory 3 as address 29.
0, and if there is a change compared to data 31 from the memory 30, writes new data to the memory 30 and outputs it as position change information 7.

Note that each control rod interface circuit 14 has a signal relay function.

With the above configuration, the address of the control rod position information 6 to be scanned by the selector 25 is determined by the control rod address data 22 sent from the control rod drive device and the scan address 19 generated by the counter 20 within the device. Under the control of the control circuit 18, the control circuit 18 alternately switches between the two. The control circuit 18 is the drive control rod address reception interface 2
When there is a drive command signal 15 from 3, the switching signal 17 is changed, and control rod address data 22 and scan address 19 are alternately selected as address output 24.

As a result, the scan signal 12 output from the transmission interface 26 becomes a signal that alternately selects the control rod that is being driven and the other control rods, so the control rod position signal 13 is sent every two times. Information on the drive control rod is output from the control rod interface circuit 14 in proportion.

The control rod position data 27 received via the reception interface 28 is compared by the motion detection circuit 32 with data stored in the memory 30 at the same address. At this time, if there is a mismatch, it means that the control rod position has changed, and the operation detection circuit 32 stores new control rod position data 27 in the memory 30, updates it, and outputs it as position change information 7.

In this embodiment, the control rod position data 27 sent is 2
Since data is obtained from the control rods that are being driven once per cycle, the detection cycle when a change occurs will be a maximum of 2/total number of control rods compared to the detection cycle when the control rods are continuously advanced. It is shortened to . The update cycle of the control rod position information when the control rods are not driven is the same as that of the conventional device because the control rod position information is constantly scanned using the scan address 19, and the total scan time is not increased.

Scanning the position information of general control rods that are not in selective drive,
By sequentially incrementing the counter 20 using the clock signal 16, continuous scan addresses are generated. The counter 20 is incremented.

This is performed while the control rod address data 22 is selected by the selector 25.

An embodiment of the present invention has been described above, but in addition to the method of alternately selecting and scanning the position information of the driving control rod and other general control rods each time as in this embodiment, It is also possible to configure the drive control rod to be scanned after scanning a plurality of rods. Incidentally, even when a plurality of control rods are driven simultaneously, the speed can be increased by performing the above-mentioned alternate scanning while sequentially changing the control rod addresses during driving.

[Effects of the Invention] As described above, according to the present invention, one important change in the position of the control rod during driving can be detected at extremely high speed.

This reduces the response time of the entire control rod drive system.

Processing allowable time is greatly improved. Furthermore, according to the present invention, scanning when the control rods are not driven is the same as before.
Furthermore, according to this high-speed position change detection function, the above effects can be achieved without imposing a burden on the scan time when not driven.

It enables detection of high-resolution position changes that can be used to measure control rod operating speeds. Therefore, it is possible to share functions with the control rod operating speed measuring device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the control rod position indicating device of the present invention, and FIG. 2 is a block diagram of the entire control rod drive mechanism. ■... Reactor vessel, 2... Control rod, 3... Control rod drive mechanism, 4... Control rod insertion/extraction command, 5... Control rod drive device, 6... Control rod Position information, 7... Position change information, 8... Control rod position indicating device, 9... Block signal, 10... Process computer, 11... Control rod operation request,] 2... Scan signal, 13... Control rod position signal, 14... Control rod interface circuit, 15... Drive command signal, 16... Clock signal. 17... Switching signal, 18... Control circuit, 19...
Scan address, 20... Counter, 21... Control rod selection drive signal, 22... Control rod address data,
23... Drive control rod address reception interface,
24...Address output, 25...Selector, 26.
...Transmission interface, 27...Control rod position data. 28... Reception interface, 29... Address, 30... Memory, 31... Data, 32... Operation detection circuit.

Claims (1)

[Claims] A control rod position indicating device that scans and sequentially captures the position information of each of multiple control rods used to adjust the reactor output receives a control rod selection drive signal output from a control rod drive device, and then drives the control rod. comprising a circuit for extracting address data, and a selection circuit for alternately switching and selecting the address data and control rod scanning address data generated inside the control rod position indicating device while the control rod is being driven; By alternately taking in the position information of the control rod currently selected and being driven by the control rod drive device and the position information of other control rods using the function of the selection circuit, the position information of the control rod being selected and being driven is updated. 1. A control rod position indicating device, characterized in that the control rod position indicating device is capable of indicating the position of a control rod without having to complete scanning of all control rods.