JP2004020409A - Radiation control monitor - Google Patents

Abstract

A radiation control monitor for monitoring a radiation level of a nuclear facility measures a total amount of contamination density of an object to be measured by a radiation detector, monitors only the presence or absence of radioactive contamination based on the result, and monitors the object to be measured. He did not go to the point of contamination.
In addition, it takes an enormous amount of measurement time to identify the contaminated part of the measured part.
A radiation level of an object to be measured is monitored by a plurality of radiation detectors arranged so as to divide a surface to be measured of the object to be measured, and usually only determination of radioactive contamination of the object to be measured is performed. When radioactive contamination is detected in the measured object, management is performed so as to specify a contaminated location.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a radiation management monitor that is used for radiation management in a nuclear facility such as a nuclear power plant, and that monitors a radiation level of a person, an article, and the like based on a detection signal output from a radiation detector.
[0002]
[Prior art]
At nuclear facilities such as nuclear power plants, continuous monitoring of radiation levels by radiation control monitors to check the effects of radiation on equipment, the environment, and the human body, and periodic or as needed radioactive contamination (hereinafter simply referred to as contamination). Measurement) is being performed.
[0003]
A conventional radiation control monitor measures, for example, the contaminated surface density of the surface of an object to be measured, which is moved to a measurement location on a conveyor, or the total amount of contaminated density of internal contamination, using a radiation detector. Judge whether the contamination of the measured object is below the control level.If the contamination is below the control level, enable the removal to the non-managed area.If the contamination exceeds the control level, go to the non-managed area. Management, such as prohibiting the taking out of personal computers.
[0004]
Normally, the monitoring of the radiation level involves checking the presence or absence of contamination (confirmation of the ANN output) for the entire DUT, and does not require identification of the contaminated portion of the DUT. If the contaminated part of the measured object can be specified, the subsequent decontamination work becomes easier, and safety during maintenance and inspection is further ensured.
[0005]
[Problems to be solved by the invention]
If an attempt is made to specify a contaminated portion of the object to be measured by the radiation management monitor, the contaminated portion can be specified if the radiation detector is divided into a plurality of radiation detectors or a plurality of radiation detectors are prepared. However, if it is attempted to monitor all the DUTs to identify the location of the contamination due to the rare occurrence of contaminants, the monitoring of the DUT will be enormous compared to monitoring only the presence or absence of contamination. Measurement time is required.
For this reason, the number of processes per unit time decreases, and the processing capacity decreases.
[0006]
In view of the above, it is an object of the present invention to provide a radiation management monitor that requires a short radiation level monitoring time, can identify a radioactive contamination site, and improves the processing capacity.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a radiation management monitor according to claim 1 is arranged so as to divide a surface to be measured of an object to be measured along an object to monitor a radiation level of the object to be measured. A radiation management monitor having a radiation detector and an alarm determination unit that receives the detection signal from the radiation detector, determines whether the radiation level of the measured object is below the management level, and measures radioactive contamination, When determining the presence or absence of radiation contamination of the DUT, the determination is based on the total value of the radiation levels from multiple detectors.When identifying the contaminated location of the DUT, the radiation level is determined from the signals of the individual radiation detectors. Is characterized by measuring the positional distribution of.
According to the present invention, it is possible to determine the presence or absence of radioactive contamination from the total value of the radiation levels, and it is possible to specify the contaminated location of the object to be measured as necessary from the positional distribution of the radiation levels.
[0008]
The invention of the radiation management monitor according to the second aspect is the radiation management monitor according to the first aspect, which normally only determines the presence / absence of contamination of an object to be measured, and detects a case where contamination is detected in the object to be measured. It is characterized by specifying the location of contamination.
According to the present invention, only when a radioactive contamination is detected in the measured object, the contamination location of the measured object is specified from the positional distribution of the radiation level.
[0009]
In the radiation management monitor according to the third aspect, in the radiation management monitor according to the second aspect, when contamination is detected in the object to be measured, the contamination location is identified, so that the contamination is identified again at a time corresponding to the contamination level. It is characterized in that measurement is performed.
[0010]
According to the present invention, the expected value of the radiation level that can be individually output by each radiation detector is calculated from the total value of the input radiation levels, and the measurement time for identifying the contaminated portion is calculated based on the calculation result. After the determination, the measurement for specifying the contaminated site is performed with this measurement time.
[0011]
According to a fourth aspect of the present invention, in the radiation management monitor according to the second aspect, when measuring the radioactive contamination of an object to be measured that is moved by a conveyor or the like, contamination of the object to be measured may occur during the measurement. When it is detected, the movement by the conveyor is stopped, and the measurement of the contamination location is performed.
According to the present invention, the determination of the presence or absence of contamination is performed in a state where the conveyor is operated, and only when the contamination is found, the conveyor is stopped and the location of the contamination is specified.
[0012]
According to a fifth aspect of the present invention, in the radiation management monitor according to the first or second aspect, the contamination level of the measured object and each part of the measured object are simultaneously displayed at the time of specifying the contamination location of the measured object. A divided display screen is provided.
According to the present invention, the display screen of the monitor is divided, and the location of contamination is specified while observing the radiation level of each part of the DUT displayed on each divided screen.
[0013]
According to a sixth aspect of the present invention, in the radiation management monitor according to the fifth aspect, a numerical value of the degree of contamination of the measured object is displayed.
According to the present invention, the display screen of the monitor is divided, and the contamination part is specified while observing the numerical value of the radiation level of each part of the DUT displayed on each divided screen.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a view showing a first embodiment of the present invention. In FIG. 1, radiation management monitors of the present invention are arranged along an object (not shown) so as to divide a measurement target surface of the object. A plurality of radiation detectors 1 that detect radiation of the object to be measured and output detection signals according to the radiation dose, monitor the detection signals from the radiation detectors 1 and process the signals into information according to the purpose. The signal processing unit 2 outputs the signal to the outside, and the radiation monitoring monitor device 26 that grasps the positional distribution of the radiation level of the object to be measured and specifies a contamination location.
When the measured object moves near the radiation detector 1 by a conveyor (not shown), the radiation dose is detected.
[0015]
The signal processing unit 2 includes a plurality of detector signal processing units 6 that independently process detection signals from the respective radiation detectors 1 and a detector signal addition process that adds detection signals from the radiation detectors 1 and processes the sum as a total value. And a part 16.
[0016]
A detector signal processing unit 6 is a digital signal conversion unit 7 for converting a detection signal input from the radiation detector 1 into a digital signal, and a digital filter for receiving a digital signal converted by the digital signal conversion unit 7 and performing a radiation dose calculation. And a digital output unit 9 for converting a digital signal calculated in the digital filter unit 8 into an analog signal S1 and outputting the analog signal S1 to the outside.
[0017]
The detector signal addition processing section 16 includes an addition circuit 17 for receiving and adding a digital signal obtained as a result of operation in the digital filter section 8, a digital filter section 18 for receiving a signal from the addition circuit 17 and performing radiation dose calculation, and a digital filter section. An analog output section 19 converts the digital signal calculated in 18 into an analog signal S2 and outputs the same to the outside. The digital filter section 18 determines contamination from the digital signal calculated and outputs a trip signal S3 and the like as necessary. It comprises an alarm judging section 20 and an adder circuit 17, and a digital filter section 18 and a data transmitting section 21 for externally outputting a signal from the alarm judging section 20 as a signal S4 to a host computer. The radiation monitoring monitor device 26 receives a digital signal S5 from the detector signal processing unit 6.
[0018]
In the radiation management monitor according to the first embodiment of the present invention having such a configuration, when radiation from an object to be measured enters each radiation detector 1, a detection signal corresponding to the radiation level is generated by the signal processing unit. 2 is transmitted to the second detector signal processing unit 6. The detection signal transmitted to the detector signal processing unit 6 is converted from an analog signal to a digital signal by a digital signal conversion unit 7 and then input to a digital filter unit 8 that calculates a radiation dose.
[0019]
When the purpose is to detect the presence or absence of contamination of the device under test, the output signal output from the digital filter unit 8 is input to the addition circuit 17 of the detector signal addition processing unit 16. In the adding circuit 17, the radiation levels calculated based on the signals from the plurality of radiation detectors 1 are summed, and based on the sum, the alarm judgment unit 20 judges whether or not the contamination is below the control level. , The presence or absence of contamination is determined, and a trip signal S3 or the like is output as necessary. The signal output from the digital filter unit 18 is converted from a digital signal to an analog signal in an analog output unit 19 and output to the outside. The result of the presence / absence of contamination in the alarm determination unit 20 and the radiation level calculation result in the digital filter unit 18 are transmitted to the host computer via the data transmission unit 21.
[0020]
On the other hand, when the purpose is to identify a contaminated portion of the device under test, the output signal from the digital filter unit 8 of the detector signal processing unit 2 is converted from a digital signal to an analog signal by the analog output unit 9. The radiation signal is output to the outside, and the output signal S5 from the digital filter unit 8 is inputted as a digital signal to the radiation monitoring and monitoring device 26 to grasp the positional distribution of radiation of the object to be measured and to specify a contaminated portion.
[0021]
As described above, in the radiation management monitor / monitoring device 26, the radiation detection is performed using the plurality of radiation detectors 1 arranged so as to divide the surface to be measured along the measured object. Independently handling the signals from, the position distribution of the radiation level can be detected and the contamination site of the measured object can be specified as necessary.
[0022]
Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, the same parts as those in FIG. As shown in FIG. 2, normally, the detection signals from the respective radiation detectors 1 are summed up by an addition circuit 17 of a detector signal addition processing section 16, and from the total value, the presence / absence of contamination of the measured object is determined by an alarm determination section 20. Do with. Accordingly, the radiation monitoring monitor 26 is not operating since the contamination location is not normally specified. When the contamination of the measured object is detected by the alarm determination unit 20, the detection signal S5 of each radiation detector 1 is input from the detector signal processing unit 6 to the radiation monitoring monitor device 26, and based on the positional distribution of the radiation level. Identify contaminated sites.
[0023]
According to the second embodiment of the present invention, normally, only detection of the presence or absence of contamination is performed, and when the contamination is detected by the alarm determination unit 20, the detection signal S5 of each radiation detector 1 is processed by the detector signal processing. Since the contamination point is input from the unit 6 to the radiation monitoring monitor device 26 and the contamination point is specified, the monitoring time of the radiation level is shorter than in the case where the monitoring of the contamination point is performed for all the measured objects. And the processing capacity can be improved.
[0024]
Next, a third embodiment of the present invention will be described with reference to FIG. In FIG. 3, the same portions as those in FIG. As shown in FIG. 3, when contamination of the object to be measured is detected by the alarm determination unit 20, the sum of the radiation levels from the radiation detectors 1 detected at this time is added from the addition circuit 17 to the radiation monitoring monitor device 26. An expected value of a radiation level that can be individually output by each radiation detector 1 is calculated from the total value of the radiation levels transmitted to the radiation monitoring monitor device 26 as an abnormal signal S6, and contamination is calculated based on the calculation result. Determine the measurement time for location identification. With this measurement time, measurement is performed again to specify the contaminated site.
[0025]
According to the third embodiment of the present invention, signal input to the radiation monitoring and monitoring device 26 is not performed at all times, and the radiation monitoring and monitoring device 26 estimates and measures necessary measurement time when identifying a contaminated site. Therefore, the monitoring time of the radiation level can be shortened, and the processing capacity can be improved.
[0026]
Next, a fourth embodiment of the present invention will be described with reference to FIG. In FIG. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 4, in the configuration of the second embodiment in which the radiation amount of the object to be measured that moves near the radiation detector 1 is measured by the conveyor, the conveyor control circuit 22 is provided on the output side of the alarm determination unit 20. When the contamination of the measured object is detected by the alarm determination unit 20, a signal S7 for stopping the conveyor is output, the conveyor is stopped, and the contaminated measured object is stopped in the detection device. And After detection of the contamination by the alarm determination unit 20, a signal is input to the radiation monitoring and monitoring device 26, and the identification of the contaminated portion is started. Therefore, by stopping the object to be measured in the detection device, the contaminated portion of the stationary object can be detected. It becomes the same as the specified state.
[0027]
According to the fourth embodiment of the present invention, the determination of the presence or absence of contamination is performed in a state where the conveyor is operated, and only when contamination is found, the conveyor is stopped and the contamination location is specified. It can be performed accurately and the processing capacity can be improved.
[0028]
Next, a fifth embodiment of the present invention will be described with reference to FIG. In FIG. 5, the same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description will be omitted. As shown in FIG. 5, in the configuration of the fourth embodiment, a device capable of outputting a signal S8 for changing the moving speed of the conveyor is installed in the radiation monitoring monitor device 26. The conveyor speed can be selected from “contamination detection”, “contamination point identification”, and “manual”. The conveyor speed for "contamination detection" and "contamination point identification" can be set in advance. In the case of "manual", the conveyor speed can be freely specified.
According to the fifth embodiment of the present invention, it is possible to arbitrarily select and set the conveyor speed according to the judgment of the supervisor, to provide flexibility in operation, and to improve the processing capacity.
[0029]
Next, a sixth embodiment of the present invention will be described with reference to FIG. In FIG. 6, the same portions as those in FIG. 1 are denoted by the same reference numerals, and detailed description will be omitted. As shown in FIG. 6, in the configuration of the fourth embodiment in which the radiation amount of an object to be measured moving near the radiation detector 1 is detected by a conveyor, a conveyor control circuit 22 is installed in the signal processing unit 2. When the alarm determination unit 20 detects contamination in the object, the object is passed from the detection device until no significant contamination is detected, and when the alarm determination unit 20 returns to the signal output indicating no abnormality, The conveyor control circuit 22 can output a signal S9 for reversing the unloading direction of the measurement object. When an abnormality is detected by the alarm determination unit 20, the total value of the detected radiation levels from the respective radiation detectors 1 is transmitted from the adding circuit 17 to the radiation monitoring monitor device 26, and the radiation level input by the radiation monitoring monitor device 26 is transmitted. The expected value of the radiation level that can be output individually by each radiation detector 1 is calculated from the total value of the above, and the measurement time for specifying the contaminated portion is determined based on the calculation result. The conveyor speed is calculated from the determined measurement time, and the signal S10 for changing the conveyor speed is fluctuated with the conveyor inversion signal output from the conveyor control circuit 22 so that the radiation monitoring monitor device 26 can output the signal S10.
[0030]
According to the sixth embodiment of the present invention, a signal is not input to the radiation monitoring and monitoring device 26 during normal times, and the radiation monitoring and monitoring device 26 estimates and measures the required measurement time when identifying a contaminated site. Therefore, the monitoring time of the radiation level can be shortened, and the processing capacity can be improved.
[0031]
Next, a seventh embodiment of the present invention will be described with reference to FIG. As shown in FIG. 7, in addition to the operation panel unit 33 of the detection device 32 installed on the conveyor 31 always facing the operator 30, for example, a monitor screen 35 of the DUT 34 is installed on the opposite side surface of the detection device 32. I do.
According to the seventh embodiment of the present invention, it is possible to easily monitor a third person 36 whose viewpoint is different from that of the operator 30.
[0032]
Next, an eighth embodiment of the present invention will be described with reference to FIG. As shown in FIG. 8, the radiation detector according to the present embodiment includes 16 divided scintillation detectors 37 arranged so as to divide the surface to be measured of the object to be measured. The display screen 38 of the object to be measured and the degree of contamination is divided in consideration of the arrangement position of each radiation detector, and the divided screen 39 divides the radiation level into μSv / h based on the output signal from each radiation detector. It can be displayed on the radiation level display unit 40 in units.
[0033]
According to the eighth embodiment of the present invention, the display screen of the monitor is divided and the radiation level is displayed on each of the divided screens. Is improved.
[0034]
Next, a ninth embodiment of the present invention will be described with reference to FIG. In FIG. 9, the same parts as those in FIG. As shown in FIG. 9, the split screen 39 can set a preset color such as red, yellow, or blue as a background color of the screen based on a detection signal from each radiation detector in accordance with the radiation level.
According to the ninth embodiment of the present invention, since the radiation level can be detected based on the color of the screen background, the operator can easily determine the contaminated area, and the processing capacity is improved.
[0035]
Next, a tenth embodiment of the present invention will be described with reference to FIG. In FIG. 10, the same parts as those in FIG. As shown in FIG. 10, regarding the display of the color corresponding to the radiation level on the divided screen 39, the display is uniformly the same as 0 count, assuming that the background level is a fluctuation range of the background level set in advance.
[0036]
According to the tenth embodiment of the present invention, since the color of the screen background is displayed in the same color within the fluctuation range of the background level, the operator can more easily determine the contaminated area, and the processing capacity is improved.
[0037]
Next, an eleventh embodiment of the present invention will be described with reference to FIG. In FIG. 11, the same portions as those in FIG. 8 are denoted by the same reference numerals, and detailed description will be omitted. As shown in FIG. 11, considering the measurement area covered by each radiation detector arranged so as to divide the measurement target surface of the DUT 34, the surface contamination density is calculated based on the measurement area and the radiation level of the DUT. Is calculated. This is displayed on the surface contamination density display section 41.
[0038]
According to the eleventh embodiment of the present invention, since the regulation of radiation management of articles, people, etc. is based on the surface contamination density, it is easy to judge the contamination location by displaying the surface contamination density, and the processing capacity is improved. .
[0039]
Next, a twelfth embodiment of the present invention will be described with reference to FIG. In FIG. 12, the same portions as those in FIG. 8 are denoted by the same reference numerals, and detailed description will be omitted. As shown in FIG. 12, when the radiation level measured by each detector reaches a preset numerical value, “x” is displayed at the center of the divided screen 35.
According to the twelfth embodiment of the present invention, it becomes easier for an operator to visually determine a contaminated portion by displaying “x”, and the processing capacity is improved.
[0040]
Next, a thirteenth embodiment of the present invention will be described with reference to FIG. In FIG. 13, the same portions as those in FIG. 1 are denoted by the same reference numerals, and detailed description will be omitted. As shown in FIG. 13, normally, the output signals from the respective radiation detectors 1 are summed up by the addition circuit 17 of the detector signal addition processing unit 16, and a radioactive contamination warning judgment 20 is performed from the total value. Normally, the location of the contamination is not specified, but the detection signal of each radiation detector is input from the detector signal processing unit 6 to the radiation monitoring monitor device 26, and the data is stored in the storage unit 27. If it is detected that the object to be contaminated is present, the measurement is continued, and in addition to the data stored in the storage unit 27 when the presence or absence of contamination is determined, the detector signal processing unit 6 sends the individual radiation detection signals to the radiation monitoring monitor device 26. The apparatus signal S5 is input so that the positional distribution of the radiation level can be grasped.
[0041]
According to the thirteenth embodiment of the present invention, when determining the presence or absence of contamination, by accumulating data from each of the detectors, the measurement time can be reduced when the contamination is specified after the abnormality is detected. The processing capacity can be improved.
[0042]
【The invention's effect】
As described above, according to the present invention, a plurality of radiation detectors arranged to divide the measurement target surface of the measurement target along the measurement target and monitor the radiation level of the measurement target, and In a radiation management monitor having a detection signal input and determining whether the radiation level of the DUT is below the control level and measuring the radioactive contamination, the determination of the presence or absence of radiation contamination of the DUT is performed. When performing, the determination is made based on the total value of the radiation levels by a plurality of detectors, and when specifying the contaminated part of the measured object, the positional distribution of the radiation levels is measured from the signals of the individual radiation detectors. Therefore, the radiation level monitoring time can be shortened, the location of radioactive contamination can be specified, and a radiation management monitor with improved processing capability can be obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of the present invention.
FIG. 2 is a block diagram showing a second embodiment of the present invention.
FIG. 3 is a block diagram showing a third embodiment of the present invention.
FIG. 4 is a block diagram showing a fourth embodiment of the present invention.
FIG. 5 is a block diagram showing a fifth embodiment of the present invention.
FIG. 6 is a block diagram showing a sixth embodiment of the present invention.
FIG. 7 is a perspective view showing a seventh embodiment of the present invention.
FIG. 8 is a front view showing an eighth embodiment of the present invention.
FIG. 9 is a front view showing a ninth embodiment of the present invention.
FIG. 10 is a front view showing a tenth embodiment of the present invention.
FIG. 11 is a front view showing an eleventh embodiment of the present invention.
FIG. 12 is a front view showing a twelfth embodiment of the present invention.
FIG. 13 is a block diagram showing a thirteenth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Radiation detector, 2 ... Signal processing unit, 6 ... Detector signal processing part, 7 ... Digital signal conversion part, 8 ... Digital filter part, 9 ... Analog output part, 16 ... Detector signal addition processing part, 17 ... Adder circuit, 18 digital filter section, 19 analog output section, 20 alarm determination section, 21 data transmission section, 22 conveyor control circuit, 26 radiation monitoring monitor device, 30 operator, 31 conveyor, 32 Detecting device 33 Operation panel 34 Object under test 35 Monitor screen 36 Third party 37 Scintillation detector 38 Display screen 39 Split screen 40 Radiation level display section

Claims (6)

A plurality of radiation detectors arranged to divide the surface to be measured of the vertical object to be measured along the object to be measured and monitoring the radiation level of the object to be measured, and the object to be measured by inputting a detection signal from the radiation detector In a radiation management monitor having an alarm determination unit for determining whether the radiation level of the radiation is below the control level and measuring the radioactive contamination, when determining the presence or absence of radiation contamination of the measured object, a plurality of detectors A radiation management monitor characterized in that a radiation level is measured based on a signal of each radiation detector to determine a contaminated portion of an object to be measured, based on a total value of radiation levels. 2. The radiation management monitor according to claim 1, wherein, at normal time, only the presence or absence of contamination of the measured object is determined, and when contamination is detected in the measured object, the contamination location is specified. 3. The radiation management monitor according to claim 2, wherein when contamination is detected in the object to be measured, measurement is performed again at a time corresponding to the contamination level in order to identify a contamination portion. When measuring radioactive contamination of an object moving by a conveyor or the like, when contamination is detected in the object to be measured during the measurement, the movement by the conveyor is stopped and the measurement of the contamination location is performed. The radiation management monitor according to claim 2. 3. The radiation management monitor according to claim 1, wherein a divided display screen is provided for simultaneously displaying the degree of contamination of the object to be measured and each part of the object to be measured at the time of specifying a contamination location of the object to be measured. . The radiation management monitor according to claim 5, wherein a numerical value of the degree of contamination of the measured object is displayed.

Images