JPH0161191B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a portable radiation measuring device for monitoring radiation levels in a radiation controlled area in a nuclear power plant, and particularly to improvements in automatic recording and reproducing means for measuring data including measurement positions.

Monitoring the radiation level in the radiation controlled area of a nuclear power plant and controlling and restricting the exposure dose of those who enter the controlled area is one of the extremely important tasks in radiation control of a nuclear power plant. Conventionally, as a means for monitoring such radiation levels, radiation levels have been measured using a portable radiation measuring device called a survey meter, and the measured values have been manually read and recorded.

FIG. 1 is a block diagram showing the configuration of the above-mentioned conventional portable radiation measuring device. As shown in FIG.
is given to indicate the radiation level such as the dose rate, and each device 1 to 3 is supplied with power from a battery-type power supply device 4.

In order to monitor radiation levels using the device with the above configuration, a layout map of the floors in the controlled area is prepared, and the measurement person marks the measurement points on the layout map with circles, etc. and records the measured values at the measurement points. This is done by writing.

Such conventional measurement means have the following problems. That is, in nuclear power plants and the like, there are reactor buildings, waste treatment buildings, etc. For this reason, it is necessary to carry out the measurements and records for each floor in each of these buildings, and the number of measurement points on one floor may reach more than ten. Increasing the number of measurement points improves the accuracy of the radiation dose rate distribution and is meaningful in implementing detailed radiation management, but on the other hand, it requires processing a correspondingly large amount of measurement data. Therefore, not only does this increase the burden on the radiation administrator, but also the amount of radiation exposure increases as the measuring person's work time within the radiation controlled area increases accordingly. Furthermore, since the measured values are read and recorded manually, there is a high possibility that recording errors may occur due to errors.

On the other hand, it is possible to reduce the administrative work of radiation managers and improve the efficiency of the administrative work by processing measurement data of radiation monitoring using a data processing device such as an electronic computer. However, even if such data management is automated, the conventional radiation measurement and recording means described above lack a means to input measurement points and measured values into a data processing device, making the input work extremely complicated. This means that the usefulness of automatic data management by the data processing device is halved.

The present invention was made in consideration of these circumstances, and its purpose is to eliminate the risk of human recording errors occurring when a measurement person enters a radiation controlled area to measure radiation levels. In addition to being able to obtain accurate data without any problems, even when measuring a large number of measurement points to obtain a highly accurate dose rate distribution, measurements can be made efficiently in a short time, reducing the burden on the person performing the measurement. It is an object of the present invention to provide a portable radiation measuring device that can reduce the exposure dose of the measuring person himself, and also contributes to reducing radiation management work and improving efficiency.

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

FIG. 2 is a block diagram showing a schematic configuration of an embodiment of the present invention. In FIG. 2, the radiation detector 11 includes a GM counter, a scintillation counter,
This detector 11 uses an ionization chamber, etc.
The output signal is input to the level measuring device 12. The level measuring device 12 amplifies the output signal of the detector 11 and supplies it to the display 13, and also latches the measured value at that time in response to a latch command signal from a position determining device 18, which will be described later. Power is supplied from a battery type power supply device 14 to each of the above-mentioned devices and each device described below.

The measurement position input device 15 is a device for inputting the position where radiation is detected by the radiation detector 11 as a measurement point, and includes a light emitter 16 for specifying the measurement point and a local input of the light emitted from the light emitter 16. A photodetector 17 receives light and converts it into an electrical signal corresponding to the light receiving position, that is, a measurement point, and a measurement point is determined from the output signal of this photodetector 17 and a measurement position signal is provided to a data controller 19 described below. At the same time, the position determining device 18 latches the measured value of the level measuring device 12.

The data controller 19 inputs the measured position signal outputted from the position determiner 18 and the latched measured value signal outputted from the level measuring device 12, and converts the measured value and measurement point into storage data. is converted into and given to the storage device 20. The storage device 20 uses a recording medium such as a cassette-type magnetic tape or a magnetic recording card, and is capable of storing data from the data controller 19 and reading out the stored contents at any time after the measurement is completed. There is.

FIG. 3 is a perspective view showing the appearance of the apparatus of the present invention in which each of the apparatuses shown in FIG. 2 is housed in a compact portable case 21. As shown in FIG. 3, the light emitter 16 is provided in a light emitting section 16b consisting of a point light source at the tip of a rod-shaped base 16a, and is connected to a flexible connection cord 22 drawn out from the case 21. has been done. Also, photodetector 1
7 is housed so that its surface is flush with the upper surface of the case 21. Note that the photodetector 1
The configuration of 7 will be described later. Positioning pins 23a, 23 are provided at each corner of the upper surface of the case 21.
b, 23c, and 23d are implanted, and the sheet 24 is positioned by fitting these pins 23a to 23d into holes 24a to 24d of the layout sheet 24 made of a translucent member. ing.

Figure 4 shows the surface sheet 2 placed on the upper side of the case 21.
FIG. As shown in FIG. 4, the layout of the floors in the controlled area where radiation level measurements are to be made is drawn on the surface of the layout sheet 24. In this way, when a predetermined position on the sheet 24 is specified with the tip of the light emitter 16, the specified position is detected by the photodetector 17.

FIG. 5 is a schematic side view showing the mechanism by which the photodetector 17 detects the designated position of the light emitter 16. As shown in FIG.
, a condenser lens 17b disposed below the light-transmitting plate 17a, and a light receiver 17c disposed at the focal point of the condenser lens 17b. In this way, when the light emitting part 16b of the light emitter 16 points to a measurement point on the layout drawing sheet 24, the light emitted from the light emitting part 16b passes through the light transmitting plate 17a and is focused by the condensing lens 17b, and the light is transmitted to the light receiver 17c. It is irradiated to a predetermined position on the top.

FIG. 6 is a plan view of the light receiver 17c. As shown in FIG. 6, the light receiver 17c has light receiving elements A made of, for example, charge-coupled devices (CCD) arranged in a matrix, and each element A is arranged on a plane. It will indicate the coordinate point. The position determiner 18 determines which light receiving element A of the light receiver 17c is irradiated with the light condensed by the condensing lens 17b.

FIG. 7 is a block diagram showing the configuration of the position determiner 18. As shown in FIG. 7, this position determiner 18 uses a pulse signal S1 from the sweep pulser 31 to search the output signal of the photodetector 17 using, for example, a gate circuit, and the searched signal S2 is at a certain level. The discriminator 32 determines whether the level is above a certain level, and if it is above a certain level, the signal S1 from the sweep pulser 31 is sent.
The discriminator 32 is sent to the position counter 33 which counts clock pulses in synchronization with the
The stop trigger is arranged to provide a signal S3. Thus, the count of the position counter 33 indicates the position coordinates of the light irradiated onto the photodetector 17. In other words, this position determiner 1
8 utilizes the fact that the light receiving output signals of each light receiving element A of the light receiver 17c are sequentially extracted as the output of the photodetector 17. Above position counter 3
3 is given as a measurement position signal from the terminal 34 to the data controller 19, and the stop trigger signal S3 is given from the terminal 35 to the level measuring device 12 of the radiation detection system as a latch command signal.

Next, how to use and operate the apparatus configured as described above will be explained. When measuring radiation, as shown in FIG. 4, a layout drawing sheet 24 depicting the layout of the radiation controlled area to be measured is loaded onto the top of the case 21, a storage medium is loaded into the storage device 20, and the measurement is carried out. Start. The output signal from the radiation detector 11 is sent to a level measuring device 12.
The signal is amplified and displayed on the display 13. on the other hand,
The measurer uses sheath 2 to indicate the location where the measurement is actually being made.
4 is designated by the tip of the light emitter 16. Then, the light emitted from the light emitting portion 16b of the light emitter 16 is detected by the photodetector 17, and the position determiner 18 determines the measurement point. That is, the sweep pulser 31 continuously sends out a pulse signal S1 of a predetermined period as shown in FIG.
is searching for the output signal. Now, if an output signal S2 of a certain level L or higher exists at time t1, this signal S2 is captured by the discriminator 32 and input to the position counter 33 as a stop trigger signal S3, and the level of the radiation detection system is It is input to the measuring device 12 as a latch command signal.
Thus, the position counter 33 stops counting at time t1. The contents of this counter 33 indicate the measurement point and are sent to the data controller 19 as a measurement position signal. Further, the level measuring device 12 latches the measured value at the time when the latch command signal is applied. This latched measurement value is then input to the data controller 19. Then data controller 1
9 converts the measured value signal and the measured value signal into storage data, and stores this in the storage device 20. After the measurement is completed, when processing the measurement data, take out the storage medium from the storage device 20,
This is loaded into a data processing device such as an electronic computer to process the data.

When the measurement for one measurement point is completed, the position determination device 18 is reset by a reset switch (not shown), and the latched state of the level measurement device 12 is released.

Thereafter, the series of operations described above is repeated in the same manner, and thereby measurements at each measurement point are performed one after another.

Note that the present invention is not limited to the above embodiments. For example, the storage device may include a storage medium such as a semiconductor memory, and an interface that can be directly connected to a computer. Further, the configurations of the photodetector and position determination device are not limited to those of the embodiments, and of course, various modifications can be made using other means that perform predetermined functions.

As explained above, according to the present invention, when a measurement person enters a radiation controlled area to measure radiation levels, the measurement position and measurement value are automatically stored, thereby eliminating the possibility of human recording errors. In addition to being able to obtain accurate data without the occurrence of
Even when measuring a large number of measurement points to obtain a highly accurate dose rate distribution, the measurement can be performed efficiently in a short time and the burden on the operator can be reduced. Furthermore, since the time required for measurement can be shortened, it is possible to reduce the exposure dose of the person performing the measurement. In addition, since measurement data can be freely written and read and measurement data can be easily input to a host data processing device, it is possible to provide a portable radiation measurement device that contributes to reducing radiation management work and improving efficiency.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a conventional portable radiation measuring device, FIGS. 2 to 8 are diagrams showing an embodiment of the present invention, and FIG. 2 is a block diagram showing the overall configuration. 3 and 4 are perspective views showing the external appearance of the device of the present invention, FIG. 5 is a schematic side view showing the relationship between the light emitter and the photodetector, and FIG. 6 is a plan view of the light receiver.
FIG. 7 is a block diagram showing the configuration of the position determination device, and FIG. 8 is a signal waveform diagram of each part. 11...Radiation detector, 12...Level measuring device, 13...Display device, 14...Power supply device, 15...
...Measurement position input device, 16...Light emitter, 17...
Photodetector, 18... Position determiner, 19... Data controller, 20... Memory device, 21... Portable case, 22... Connection cord, 23a to 23d... Positioning pin, 24... Layout diagram Sheet, 31...Sweep pulser, 32...Discriminator,
33...Position counter.

Claims (1)

[Claims] 1. A radiation detector that detects radiation, a level measuring device that amplifies the output signal of this radiation detector and measures the radiation level, and measures the position where radiation is detected by the radiation detector. A measurement position input device that inputs as a point, a measurement position signal indicating the measurement point input by the measurement position input device, and a signal indicating the radiation level measured by the level measuring device, and data that is converted into storage data. The measurement position input device includes a controller, and a storage device that stores data output from the data controller and can read out the stored contents at a timely manner, and the measurement position input device includes a light emitter that specifies a measurement point on the layout drawing sheet. a photodetector that receives the light from the light emitter and converts it into an electrical signal corresponding to the measurement point, and a measurement point is determined from the output signal of this photodetector and output as a measurement position signal to the data controller. and a position determining device that simultaneously latches the measured value of the level measuring device. 2. The portable radiation measuring device according to claim 1, wherein the storage device uses a cassette-type storage medium.