JP5780997B2 - Radiation monitoring system and diagnostic method for calibration conditions thereof - Google Patents

Description

  The present invention relates to a radiation monitoring system that measures and manages radiation to be measured in a nuclear reactor facility, a spent fuel reprocessing facility, a radioactive material utilization facility, and the like.

  A field detector equipped with a radiation detector and a measurement unit and a measurement unit equipped with a counting rate meter and a reference signal source at a location different from the field are connected with an optical fiber to electrically insulate them from the transmission line. Patent Document 1 discloses a radiation counting rate meter that improves noise resistance by preventing noise from entering and reduces exposure of workers on site.

  In the radiation count rate meter of Patent Document 1, since the current pulse generated when the radiation detector detects radiation is weak, the preamplifier converts the current pulse into a voltage pulse and amplifies the analog pulse. Is output. In a measurement unit including a preamplifier and a wave height discriminator, the wave height discriminator receives this analog pulse, discriminates wave heights higher than the wave height discrimination level and outputs digital pulses in order to remove noise. This digital pulse is converted into an optical pulse by a transmitter and transmitted by an optical fiber. This optical pulse is converted back to a digital pulse by a measuring unit, and counted by a counting rate meter to be an engineering value (corresponding to a physical quantity). Measured value).

  In addition, the measurement unit generates a digital pulse having a repetition frequency proportional to the pulse height discrimination level at the reference signal source, converts it into an optical pulse, and transmits it to the measurement unit via an optical fiber. The measurement unit converts this optical pulse back into a digital pulse, and converts the repetition frequency into a voltage level so that the pulse height discrimination level can be set remotely.

JP-A-61-53583 (page 2, upper right column, line 5 to page 2, lower right column, line 7, FIG. 1)

  The radiation counting rate meter corresponding to the conventional radiation monitoring system monitors the measured radiation counting rate with the above configuration. In inspections, such as nuclear reactor facilities, spent fuel reprocessing facilities, and radioactive material utilization facilities, the radiation detectors and measurement units that have been calibrated in the inspection before the start-up of the plant correspond to the conventional measurement units. When restoring the radiation measurement device by connecting it back to the device and connecting it with a connection cable, bring the indicator radiation source and the calibrated measuring instrument to the site, and irradiate the radiation source to the radiation detector from a predetermined distance during calibration. It is confirmed that the calibration conditions are reproduced. In order to confirm the reproduction of the calibration conditions, reduction of the exposure of workers in a series of operations of carrying in and out of the index source and measuring instrument, connection and removal, and operation of the index source remains as a problem.

Here, the calibration condition is a condition corresponding to the detection efficiency obtained by the calibration work, that is, a set value of the device. In general, it is assumed that the measurement range (window) is set to a predetermined range, the high-voltage power supply is adjusted so that the system gain (spectrum peak) becomes a predetermined value, and the calibration conditions are satisfied. Calibration is performed by irradiating the radiation detector set with the calibration conditions with radiation from a standard radiation source that is a sealed radiation source that ensures traceability. The detection efficiency is a radioactivity intensity (Bq) that gives, for example, 1 cps or 1 cpm, which is obtained when the radiation detector is irradiated onto the radiation detector from a predetermined distance.

  In addition, whenever the health of the radiation monitoring system is regularly checked, an indicator source is brought to the site and irradiated to the radiation detector to check whether there is a change in net engineering values including detection efficiency. Reducing worker exposure during inspections was also an issue.

  The present invention has been made to solve the above-described problems, and minimizes the inspection time in the radiation measurement apparatus before the plant is started up, and deletes the field work in the inspection of the radiation measurement apparatus during operation of the plant. Realization and minimization of worker exposure reduction, and automatic diagnosis of calibration conditions that ensure the soundness of the detection efficiency of the radiation measurement device, improve the reliability of the radiation monitoring system and improve maintenance work. The purpose is to make it easier.

A radiation monitoring system according to the present invention is installed in a radiation control area and measures a radiation, and is installed in a calibration room in which the radiation dose is within the radiation control area but is as low as a general area. Stores calibration conditions and calibration results that calibrate the device, outputs calibration conditions and calibration results as required, and inputs and monitors the measurement results of radiation measurement devices, and calibrations input from the calibration device A radiation monitoring device that compares conditions and inspection results input from the radiation measuring device to diagnose the soundness of the system, and the radiation measuring device is detachably arranged to detect radiation and convert it into an electrical signal a detector, is detachably arranged, by measuring the electrical signal of the radiation detector, converts the radiation measurement is a measurement on radiation, the radiation measurement values Warning A measurement unit that emits an alarm when a set value is compared and deviates from a predetermined range, and supports that radiation emitted from the measurement target is detected with a predetermined detection efficiency by a radiation detector, and environmental radiation And a check radiation source mechanism that moves the check radiation source so as to irradiate or shield radiation emitted from the check radiation source built in the sampler to the radiation detector. When calibrating the radiation measurement apparatus of the radiation monitoring system according to the present invention, the radiation detector and the measurement unit moved to the calibration room are connected to each other with a cable, the measurement unit is connected to the calibration apparatus with a cable, and the calibration apparatus is When calibrating the radiation measuring apparatus, the system gain initial value based on the index peak value, which is the radiation measurement value that appears when the radiation detector is irradiated with radiation from the index radiation source of the same nuclide as the check radiation source, and The initial value of the measurement range to be managed is set, the initial value of the system gain and the initial value of the measurement range are stored in the built-in storage device as calibration conditions, and the monitoring device performs the inspection of the radiation measurement device. , radiation measuring device radiation from the check-ray source to measure the check-ray source peak value is radiation measurements expressed when irradiated to the radiation detector, Ji The system gain and measurement range set based on the peak source peak value are acquired, and each of the set stem gain and measurement range is within the allowable range based on the system gain initial value and the measurement range initial value. It is characterized by automatically diagnosing the presence of

  The radiation monitoring system according to the present invention acquires a system gain initial value and a measurement range initial value, which are reference calibration conditions, by moving the radiation detector and the measurement unit to the calibration room when calibrating the radiation measuring apparatus. When inspecting the radiation measurement apparatus, the monitoring apparatus must ensure that the stem gain and measurement range, which are measurement calibration conditions set by the radiation measurement apparatus, are within an allowable range based on the reference calibration conditions. Therefore, the work in the radiation control area in the inspection of the radiation measuring device before the start-up of the plant can be reduced to the minimum, and the work in the radiation control area in the inspection during the operation of the plant can be eliminated in principle. In radiation monitoring system, it is possible to greatly reduce exposure and automatically diagnose calibration conditions that ensure the soundness of detection efficiency. It can be achieved to facilitate the improvement and maintenance of-reliability.

It is a figure which shows the radiation monitoring system by Embodiment 1 of this invention. It is a figure which shows the structure of the radiation measuring device of FIG. It is a figure which shows the calibration apparatus and calibration jig of FIG. It is a figure which shows the parameter | index spectrum in case a radiation detector is a plastic scintillation detector. It is a figure which shows the parameter | index spectrum in case a radiation detector is a NaI (Tl) scintillation detector. It is a figure which shows the structure of the radiation measuring device by Embodiment 2 of this invention. It is a figure which shows the spectrum of the radiation detector of Embodiment 2 of this invention. It is a figure which shows the structure of the radiation measuring device by Embodiment 3 of this invention. It is a figure which shows the spectrum of the radiation detector of Embodiment 3 of this invention.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a radiation monitoring system according to Embodiment 1 of the present invention. The radiation monitoring system 80 includes a plurality of radiation measuring devices 1a, 1b to 1i, a calibration device 2, and a monitoring device 3. The radiation measuring devices 1a, 1b to 1i each measure radiation and output an engineering value (measured value associated with a physical quantity) and an alarm state. The calibration device 2 calibrates the radiation measuring devices 1a, 1b to 1i, stores the calibration conditions and the calibration results in a built-in storage device, and outputs the calibration conditions and the calibration results as required. The monitoring device 3 inputs and monitors the measurement results of the radiation measuring devices 1a, 1b to 1i, inputs the calibration conditions and the calibration results from the calibration device 2 and stores them in a built-in storage device. The health of the system is diagnosed by comparing the inspection results 1a and 1b to 1i with the calibration conditions. The radiation measuring apparatuses 1a, 1b to 1i are installed in a radiation management area, and the calibration apparatus 2 is installed in a calibration room in a radiation management area that is shielded and strengthened so as to reduce the radiation dose.

  The monitoring device 3 is connected to the radiation measuring devices 1a, 1b to 1i by first transmission cables 4a, 4b to 4i, and connected to the calibration device 2 by a second transmission cable 5. The first transmission cables 4a, 4b to 4i connect the radiation measuring apparatuses 1a, 1b to 1i and the monitoring device 3 so as to be able to transmit and receive each other, and the second transmission cable 5 includes the calibration device 2 and the monitoring device. 3 can be connected to each other to transmit and receive. The first transmission cables 4a, 4b to 4i and the second transmission cable 5 use digital electric signal communication cables or optical cables according to the I / F of the apparatus. In the following description, since the radiation measuring apparatuses 1a, 1b to 1i overlap, the radiation measuring apparatus 1a is representative, and the first transmission cables 4a, 4b to 4i are also redundantly described, so the first transmission cable 4a is used. I will explain as a representative.

  FIG. 2 is a diagram showing a configuration of the radiation measuring apparatus 1a. Fig.2 (a) is a partial cross section seen from the front of the radiation measuring device 1a, and FIG.2 (b) is a top view. The radiation measurement apparatus 1 a includes a sampler 12, a radiation detector 11, a measurement target sample 13 such as water or gas flowing into the measurement target sample chamber 61, a check radiation source mechanism 14, and a measurement unit 15. The radiation detector 11 and the measurement unit 15 are detachably disposed on the radiation measurement apparatus 1a. The radiation detector 11 detects radiation and converts it into an electrical signal. The sampler 12 includes a sampler body 43 and a sampler lid 44, and fixes the radiation emitted from the measurement target sample 13 contained therein so that the radiation detector 11 can detect the radiation with a predetermined detection efficiency. Shield external environmental radiation (not shown). The check radiation source mechanism 14 irradiates the radiation detector 11 with radiation (not shown) by moving the check radiation source 141 built in the sampler 12 by an operation signal. The measurement target sample 13 flows into the measurement target sample chamber 61 installed in the sampler 12 in the direction of the arrow in FIG. 2B from the inlet, and then flows out from the outlet.

  The measurement unit 15 receives the electrical signal from the radiation detector 11 and converts it into an engineering value, and compares the engineering value with the alarm set value and issues an alarm when the predetermined range is exceeded. That is, the measurement unit 15 has an engineering value measurement function for measuring an engineering value and a warning transmission function for transmitting an alarm. The electrical signal of the radiation detector 11 is a raw signal of the detector, and is, for example, a current or a voltage. The engineering value is a measured value associated with a physical quantity, is used for measurement observation, control, and the like, and is a value that is technically meaningful. The engineering values in the present invention are the monitor value of the lower limit dL and the upper limit dU of the measurement range to be managed, the high voltage monitor value of the high-voltage power supply, the spectrum peak value of the standard source or the check source (on the horizontal axis in FIG. 5). A certain channel value).

  The detector cable 16 connects the radiation detector 11 and the measurement unit 15. The check radiation source cable 17 connects the check radiation source mechanism 14 and the measurement unit 15. FIG. 2 shows an example in which the sampler 12 has a cylindrical shape. The measurement unit 15 is installed outside the sampler 12, and a measurement target sample 13 such as water or gas is allowed to flow through the sampler 12 as indicated by an arrow in FIG.

  FIG. 3 is a diagram illustrating a calibration device and a calibration jig. The calibration device 2 and the calibration jig 21 are installed on the calibration room floor 40 of the calibration room. FIG. 3 shows a state in which the radiation detector 11 and the measurement unit 15 are attached to the calibration jig 21. The calibration jig 21 is for attaching the radiation detector 11 and the measurement unit 15 taken out from the radiation measuring apparatus 1a. The calibration device 2 includes an I / F unit 24, a simulated pulse generation unit 25, a voltage measurement unit 26, a spectrum counting unit 27, a display operation unit 28, and a control unit 29. The radiation detector 11 and the measurement unit 15 are connected by a first test cable 22. The measurement unit 15 and the calibration device 2 are connected by a second test cable 23. The second transmission cable 5 connecting the calibration device 2 and the monitoring device 3 is omitted. In the initial stage of calibration, the index radiation source 210 is removed from the calibration jig 21.

  The standard radiation source 220 is a radiation source used when calibrating with the calibration apparatus 2 in order to obtain detection efficiency, and selects a radiation source that emits radiation quality and energy as close as possible to the dominant nuclide in the actual measurement target. . The index radiation source 210 is a radiation source that is used to generate a spectrum peak with the same nuclide as the check radiation source 141 that is a radiation source mounted on the radiation measurement apparatus 1a. In order to associate the spectrum measured by the index line source 210 and the calibration apparatus 2 with the spectrum measured by the check line source 141 and the radiation measurement apparatus 1a by energy and peak value, the index line source 210 and the check line A source 141 is used.

  The simulated pulse generator 25 generates a simulated pulse and outputs it to the measurement unit 15. The voltage measurement unit 26 inputs and measures the voltage of each part of the measurement unit 15. In a state where the input selector switch (not shown) of the measurement unit 15 is switched from the signal input to the test input and the index source 210 is removed from the calibration jig 21, the spectrum counting unit 27 performs the test point of the measurement unit 15. The waveform and spectrum of a pulse (not shown) are measured. The display operation unit 28 displays data input from the measurement unit 15 and data such as a calibration result via the control unit 29, and operates the simulated pulse generation unit 25, the voltage measurement unit 26, and the spectrum counting unit 27. Input command data. The control unit 29 controls input / output of signals or data of the I / F unit 24, the simulated pulse generation unit 25, the voltage measurement unit 26, the spectrum counting unit 27, and the display operation unit 28, and inputs various data. The data is stored in a storage device (not shown) of the calibration device 2. Further, the control unit 29 of the calibration device 2 transmits and receives to and from the monitoring device 3 when connected to the monitoring device 3 via the second transmission cable 5 as shown in FIG.

When calibrating the radiation measurement apparatus 1a, first, the worker changes the state of the radiation measurement apparatus 1a from the monitoring state to the test state in the monitoring apparatus 3, and removes the radiation detector 11 and the measurement unit 15 from the radiation measurement apparatus 1a. . The removed radiation detector 11 and measurement unit 15 are carried to the installation location of the calibration device 2, and the radiation detector 11 and measurement unit 15 are attached to the calibration jig 21. The radiation detector 11 is connected to the measurement unit 15 by the first test cable 22, and the measurement unit 15 is connected to the I / F unit 24 of the calibration apparatus 2 by the second test cable 23.

  The measurement unit 15 receives a simulated input pulse from the simulated pulse generator 25. The calibration device 2 confirms that the relative error of the linearity of the input / output of the pulse wave height of the measurement unit 15 measured by the spectrum counting unit 27 is within the allowable range. The calibration device 2 calibrates the measurement range lower limit of the measurement unit 15 and the counting operation points of the measurement range upper limit, and sets the measurement range above the measurement range lower limit and below the measurement range upper limit as the measurement range calibration value Apr. The measured range monitor value is set as the measurement range initial value Ain, and the self-diagnosis is performed that the measurement range initial value Ain is within the allowable range on the basis of the measurement range calibration value Apr. The calibration device 2 stores the measurement range calibration value Apr and the measurement range initial value Ain in the storage device of the calibration device 2. The allowable range is set by a process such as root mean square, for example, by summing up instrument errors, temperature characteristics, voltage characteristics, frequency characteristics, and the like in each of the measuring instrument 15 and the measurement unit 15 of the calibration apparatus 2.

  Next, the index radiation source 210 is installed at the same distance (predetermined distance) as the distance between the check radiation source 141 and the radiation detector 11 in FIG. 1, and an input changeover switch (not shown) of the measurement unit 15 is switched from the signal input. Switching to the test input, the radiation is emitted from the index source 210 to the radiation detector 11. Here, the index radiation source 210 is the same nuclide as the check radiation source 141. The measurement unit 15 and the spectrum counting unit 27 each measure the index spectrum. That is, the measurement unit 15 measures the index spectrum using the engineering value measurement function. The spectrum counting unit 27 of the calibration apparatus 2 receives the data of the radiation detector 11 via the measurement unit 15 and measures the index spectrum in the same manner as the measurement unit 15.

  In the case where β-rays are to be measured, the radiation detector 11 uses, for example, a plastic scintillation detector, and the check source 141 and the index source 210 use Sr-90 of a β-ray source. In addition, when γ-rays are the measurement target, the radiation detector 11 uses, for example, a NaI (Tl) scintillation detector, and the check radiation source 141 and the index radiation source 210 use Cs-137. Sr-90 is in a radiation equilibrium relationship with Y-90, and a peak appears at a position corresponding to the thickness of the plastic scintillator by a β-ray of 2.28 MeV. Cs-137 has a peak at a position corresponding to photoelectric absorption of 0.662 MeV γ-rays.

  The index spectrum detected by the radiation detector 11 will be described. FIG. 4 is a diagram showing an index spectrum when the radiation detector is a plastic scintillation detector, and FIG. 5 is a diagram showing an index spectrum when the radiation detector is a NaI (Tl) scintillation detector. The index spectrum of FIG. 4 is a diagram schematically showing the index spectrum when a plastic scintillation detector is used as the radiation detector 11 and the radiation of Sr-90, which is a β-ray source, is irradiated as the index source 210. is there. The index spectrum of FIG. 5 is a diagram schematically showing the index spectrum when the NaI (Tl) scintillation detector is used and the radiation of Cs-137, which is a γ-ray source, is irradiated as the index radiation source 210. 4 and 5, b represents a background spectrum, m represents an index spectrum superimposed on the background spectrum by irradiating with radiation from the index source 210, p represents an index peak, and dL represents an index peak. The lower limit of the measurement range is indicated, and dU indicates the upper limit of the measurement range.

A calibration method of the measurement unit 15 will be described. First, for example, the high voltage of a high-voltage power supply (not shown) applied to the radiation detector 11 is adjusted so that each index peak measured by the spectrum counting unit 27 has a predetermined value. Next, the calibration device 2 sets the final high voltage value measured by the voltage measuring unit 26 as the high voltage calibration value HVpr, and sets the high voltage monitor value, which is the high voltage value measured by the measurement unit 15 at the same time, as the high voltage. The initial value HVin is used, the high voltage initial value HVin is self-diagnosis based on the high voltage calibration value HVpr, and the high voltage calibration value HVpr and the high voltage initial value HVin are stored in the storage device of the calibration device 2. . Further, the calibration device 2 sets the system gain initial value SGin based on the peak value of the index peak p measured by the measurement unit 15, and uses the peak value of the index peak p measured by the spectrum counting unit 27 as the system gain calibration value SGpr. The system gain calibration value SGpr is used as a reference to make a self-diagnosis that the system gain initial value SGin is within the allowable range, and the system gain calibration value SGpr and the system gain initial value SGin are stored in the storage device of the calibration device 2. Here, as an example of setting the system gain initial value SGin based on the peak value of the index peak p, the peak value of the index peak p measured by the measurement unit 15 is directly used as the system gain initial value SGin.

  Usually, the lower limit dL and the upper limit dU of the measurement range of the index spectrum are set such that the width of the lower limit value and the upper limit value is set from the index peak p on the basis of the index peak p so that the spectrum shape can be sufficiently grasped. By setting the index peak p to the same fixed value in each of the measurement unit 15 and the spectrum counting unit 27 of the calibration device 2, the measurement range is set based on the index peak value p. The relationship between p and the measurement range is uniquely determined. That is, the measurement range value measured by the spectrum counting unit 27 becomes the measurement range calibration value Apr, and the measurement range value measured by the measurement unit 15 becomes the measurement range initial value Ain.

  When the measurement range calibration value Apr and the system gain calibration value SGpr are set, the index radiation source 210 is replaced with the standard radiation source 220 accommodated in the check radiation source container 42, and calibration for obtaining detection efficiency is performed. The detection efficiency obtained by replacing the standard radiation source 220 will be referred to as standard detection efficiency DEst. The detection efficiency (standard detection efficiency DEst) is stored in the storage device of the calibration device 2 as a calibration result.

When the calibration is completed as described above, the radiation detector 11 and the measurement unit 15 are reinstalled in the sampler 12 of the radiation measurement apparatus 1a, and the restoration work for restoring the radiation measurement apparatus 1a is performed, and the check radiation source mechanism 14 is driven. The radiation detector 11 is irradiated with radiation (not shown) from the check line source 141. The measurement unit 15 measures the net initial value Ct1 of the tick source, the peak value CHp1 of the tick source, the measurement range CHa1, and the high voltage value HV1 of the high voltage power supply by the engineering value measurement function. The measurement unit 15 sets the tick source peak value CHp1 as the system gain SG1, and stores the measurement range CHa1, the high voltage value HV1, the tick source net initial value Ct1, and the system gain SG1 in the storage unit (not shown) of the measurement unit 15. Store. Here, the net initial value of the tic radiation source or the net value of the tic radiation source measured during monitoring is the difference in the counting rate of the measurement range CHa1 (from the lower limit dL to the upper limit dU) before and after irradiation with radiation by the check radiation source. The net initial value of the tick source and the net value of the tick source are obtained by normalizing the sum of the count values of the hatched portions in FIG. 4 and FIG. 5 with the reference value.

  Next, operations of the calibration device 2 and the monitoring device 3 after the calibration is completed will be described. When the calibration of the radiation detector 11 and the measurement unit 15 of the radiation measurement apparatus 1a is completed and a calibration result is obtained, the calibration apparatus 2 transmits a reception request signal indicating the presence of new untransmitted data to the monitoring apparatus 3. . Upon receiving the reception request signal, the monitoring device 3 takes in the measurement range initial value Ain, the high voltage initial value HVin, and the system gain initial value SGin from the calibration device 2 as the calibration conditions of the radiation measurement device 1a, Is updated and stored in a storage device (not shown) of the monitoring device 3 (reference condition acquisition procedure). The calibration conditions stored in the calibration device 2 are reference calibration conditions. In addition, the monitoring device 3 resets the transmission of the reception request signal indicating the presence of the untransmitted data in the calibration device 2.

The worker returns the state of the radiation measuring apparatus 1a from the test state to the monitoring state in the monitoring device 3. When the monitoring state of the radiation measuring apparatus 1a is canceled in the monitoring apparatus 3, the monitoring apparatus 3 performs an initial inspection. The monitoring device 3 receives the latest measurement range CHa1, the high voltage value HV1, the tick source net initial value Ct1, and the system gain SG1 stored in the storage device built in the measurement unit 15 described above from the radiation measurement device 1a. (Diagnosis target condition acquisition procedure). The calibration conditions set in the radiation measuring apparatus 1a are measurement calibration conditions. The monitoring device 3 compares the measurement range CHa1 and the measurement range initial value Ain, the high voltage value HV1 and the high voltage initial value HVin, the system gain SG1 and the system gain initial value SGin, respectively, and performs self-diagnosis that it is within the allowable range. (Calibration condition diagnosis procedure) The diagnosis result is displayed on the display unit of the monitoring device 3. That is, the calibration condition diagnosis procedure automatically diagnoses that the measurement calibration condition is within an allowable range based on the reference calibration condition.

  The monitoring device 3 stores the diagnosis result in a built-in storage device, and starts monitoring if there is no problem in the diagnosis result. When there is a problem with the diagnosis result, the monitoring device 3 displays that fact (the diagnosis result has a problem) on a display unit (not shown). When there is a problem in the diagnosis result, the radiation detector 11 and the measurement unit 15 are removed from the sampler 12, and the calibration conditions are reset.

  The calibration conditions at the time of calibration are reproduced when the monthly inspection of the radiation measuring device 1a is carried out until the next periodic plant inspection at a nuclear reactor facility, spent fuel reprocessing facility, radioactive material utilization facility, etc. Do self-diagnosis to diagnose what you are doing. In addition, the radiation monitoring system 80 performs automatic diagnosis of the check source net value. The monthly inspection of the radiation measuring apparatus 1a is preferably performed once every 1 to 3 months by JEAG4606 nuclear power plant monitoring.

  The automatic diagnosis of the check source net value is performed as follows. The radiation detector 11 is irradiated with radiation from the check line source 141 by remote control from the monitoring device 3. For example, a check radiation source 141 attached to the tip of the radiation source driving rod 146 is moved from a lead shielding portion 63 to a lead shielding hole 62 by operating a solenoid (not shown), and radiation is detected from the check radiation source 141 as a radiation detector. 11 is irradiated. The measurement unit 15 of the radiation measuring apparatus 1a measures the check source net value Ctme. The measurement unit 15 compares the measured check source net value Ctme with the tick source net initial value Ct1 stored in the storage device and diagnoses that it is within the allowable range. As described above, the measurement unit 15 adds the diagnostic item of the check source net value and automatically diagnoses it together with the self-diagnosis item of the calibration condition.

  As described above, in the radiation monitoring system 80 of the first embodiment, the monitoring device 3 and the radiation measuring device 1a are connected by the first transmission cable 4a so that they can transmit and receive each other, and the monitoring device 3 and the calibration device 2 are connected to each other. Two transmission cables 5 are used to enable mutual transmission / reception. Further, in the radiation monitoring system 80 of the first embodiment, the check radiation source 141 of the radiation measuring apparatus 1a and the index radiation source 210 at the time of calibration are configured to have the same nuclide and have a peak appearing in the spectrum. To represent system gain. Further, in the radiation monitoring system 80 of the first embodiment, the check radiation source 141 is moved from the monitoring device 3 by remote operation, and the radiation detector 11 of the radiation measurement device 1a is irradiated with radiation from the check radiation source 141. The measurement unit 15 measures the peak value and the like from the measurement spectrum detected by the radiation detector 11. The measurement unit 15 measures the system gain SG1 and the measurement range CHa1, and determines whether the system gain SG1 is within the allowable range of the system gain initial value SGin and whether the measurement range CHa1 is within the allowable range of the measurement range initial value Ain. Self-diagnose.

Therefore, since the radiation monitoring system 80 according to the first embodiment periodically and remotely performs self-diagnosis of the system gain SG1 and the measurement range CHa1 as the calibration conditions, the health of the radiation measuring apparatus 1a in the radiation monitoring system 80 is confirmed. Can be maintained from the time of calibration to the start of operation and during operation.

  Further, since the radiation monitoring system 80 according to the first embodiment remotely diagnoses the soundness of the radiation measuring apparatus 1a, the work in the radiation control area of the worker can be reduced to the minimum. Can be significantly reduced. The work in the radiation control area of the worker is limited to the work of removing the radiation detector 11 and the measurement unit 15 from the sampler 12 of the radiation measuring apparatus 1a and the work of returning the radiation detector 11 and the measurement unit 15 to the sampler 12 after calibration. can do. That is, various setting operations and adjustment operations of the radiation measurement apparatus 1a at the installation location of the radiation measurement apparatus 1a can be made unnecessary. The calibration room where the calibration device 2 is installed is a radiation control area, but the radiation dose is as low as the general area, so the work in the calibration room is the work in the radiation control area that requires exposure dose management. Not included. The breakdown of the work time for the periodic inspection in the conventional radiation monitoring system was about 2/3 for various setting work and adjustment work, and about 1/3 for the calibration work. In the radiation monitoring system 80 of the first embodiment, the exposure during the periodic inspection work in the conventional radiation monitoring system can be greatly reduced.

  In addition, the radiation monitoring system 80 according to the first embodiment transmits data such as calibration conditions to ensure detection efficiency from the calibration device 2 and the radiation measurement device 1a to the monitoring device 3, and the data such as calibration conditions is transmitted to the monitoring device 3. As a result, the reliability of the monitoring system can be improved and the maintenance time can be reduced. Moreover, the radiation monitoring system 80 of Embodiment 1 can improve noise resistance by using an optical cable for the first transmission cable 4a and the second transmission cable 5.

  As described above, the radiation monitoring system 80 according to the first embodiment is installed in the radiation management area, and the radiation measuring device 1a that measures radiation, and the radiation dose is as low as the general area although it is in the radiation management area. A calibration apparatus 2 installed in a calibration room, storing calibration conditions and calibration results calibrating the radiation measuring apparatus, and outputting the calibration conditions and calibration results as required, and inputting the measurement results of the radiation measuring apparatus 1a for monitoring And a monitoring device 3 that compares the calibration conditions input from the calibration device 2 with the inspection results input from the radiation measurement device 1a to diagnose the soundness of the system, and the radiation measurement device 1a is detachable. A radiation detector 11 arranged to detect radiation and convert it into an electrical signal; and detachably arranged to measure an electrical signal of the radiation detector 11 and convert it into an engineering value; A measurement unit 15 that emits an alarm when a scientific value and an alarm set value are deviated from a predetermined range, and radiation emitted from the measurement target (measurement target sample 13) is detected by the radiation detector 11 at a predetermined detection efficiency. And a radiation source from a check radiation source 141 built in the sampler 12 and irradiating or shielding the radiation detector 11 with a check radiation source. 141 and a check radiation source mechanism 14 that moves 141. The radiation monitoring system 80 according to the first embodiment connects the radiation detector 11 and the measurement unit 15 moved to the calibration room with a cable (test cable 22) when the radiation measurement apparatus 1a is calibrated. 15 is connected to the calibration device 2 with a cable (test cable 23). When the calibration device 2 calibrates the radiation measurement device 1a, the radiation detector 11 is connected to the index source 210 of the same nuclide as the check radiation source 141. The system gain initial value SGin and the measurement range initial value Ain, which is the initial value of the measurement range to be managed, are set on the basis of the index peak value (value of the index peak p) that appears when the radiation is irradiated. SGin and the measurement range initial value Ain are stored in a built-in storage device as a calibration condition, and the monitoring device 3 performs the inspection of the radiation measurement device 1a. The ray measuring device 1a measures a check source peak value (value of the check source peak p1) that appears when the radiation detector 11 is irradiated with radiation from the check source 141, and based on the check source peak value. The set system gain SG1 and the measurement range CHa1 are acquired, and each of the set system gain SG1 and the measurement range CHa1 is within an allowable range based on the system gain initial value SGin and the measurement range initial value Ain. In other words, when calibrating the radiation measurement device, the radiation detector and the measurement unit are moved to the calibration room to obtain the system gain initial value and the measurement range initial value which are the calibration conditions as a reference, When inspecting the radiation measurement device, the monitoring device is a stem that is a measurement calibration condition set by the radiation measurement device. In and measurement range is diagnosed to be within the allowable range based on the standard calibration conditions, so that the work in the radiation control area in the inspection of the radiation measurement device before the start-up of the plant can be reduced to the minimum. It is possible to eliminate the work in the radiation control area in the inspection during the plant operation in principle, and it is possible to realize a significant reduction in exposure as a whole and to automatically monitor the calibration conditions to ensure the soundness of the detection efficiency, thereby monitoring the radiation. It is possible to improve the reliability of the system and facilitate maintenance work.

  The method for diagnosing the calibration conditions of the radiation monitoring system 80 according to the first embodiment obtains the reference conditions for storing the calibration conditions stored in the calibration apparatus 2 when the radiation measuring apparatus 1a is calibrated in the monitoring apparatus 3 as the reference calibration conditions. The procedure, the diagnostic condition acquisition procedure for storing the calibration condition set in the radiation measurement apparatus 1a at the time of inspection of the radiation measurement apparatus 1a in the monitoring apparatus 3 as the measurement calibration condition, and the measurement calibration condition indicates the reference calibration condition It includes a calibration condition diagnosis procedure for automatically diagnosing that it is within the standard allowable range, so that the work in the radiation control area in the inspection of the radiation measuring device before the plant start-up can be reduced to the minimum. It is possible to eliminate the work in the radiation control area in the inspection during the plant operation in principle, and it is possible to greatly reduce the exposure as a whole and the soundness of the detection efficiency. By automatically diagnosing calibration conditions to ensure, it is possible to realize the facilitation of improved and maintenance of reliability in the radiation monitoring system.

  Note that the net initial value Ct1 of the tick source may be included in the item of the calibration condition that is automatically diagnosed when monitoring is started after the calibration is completed.

Embodiment 2. FIG.
In the first embodiment, the check radiation source mechanism 14 is equipped with the check radiation source 141 having the same nuclide as the index radiation source 210. However, in the second embodiment, the first check radiation source 142 having the same nuclide as the index radiation source 210 and A second check line source 143 that has no peak expression and a spectrum appears in a wide range of the measurement region is mounted. FIG. 6 is a diagram showing the configuration of the radiation measuring apparatus according to the second embodiment of the present invention. FIG. 6A is a partial cross section seen from the front of the radiation measuring apparatus 1a, and FIG. 6B is a plan view. The radiation source drive rod 146 of the check radiation source mechanism 14 is equipped with the first check radiation source 142 and the second check radiation source 143, and the radiation detector 11 monitors the radiation from the first check radiation source 142. Irradiation was always performed in the state. That is, in the monitoring state, the first check line source 142 is located in the lead shielding hole 62 and the second check line source 143 is located in the lead shielding part 63.

  FIG. 7 shows an example schematically showing a spectrum when the radiation detector 11 is always irradiated with radiation from the first check line source 142. FIG. 7 shows the spectrum of the radiation detector according to the second embodiment of the present invention. In FIG. 7, b shows the background spectrum, n shows the noise peak included in the background spectrum, and m1 shows the first spectrum. The check source spectrum is accumulated on the background spectrum by irradiating the radiation of the check source 142, p1 indicates the check source peak, dL indicates the lower limit of the measurement range, and dU indicates the upper limit of the measurement range. Indicates. For example, by using a thin CdZnTe compound semiconductor as the radiation detector 11 for the sensor and using Am-241 as the γ-ray source as the first check radiation source 142, the measurement range as shown in FIG. The check source peak p1 can be expressed at a level (channel value) lower than the lower limit dL and higher than the noise peak n. By constantly irradiating radiation (γ rays) from Am-241 of the first check radiation source 142, a peak of 60 keV γ rays appears, and the peak value of the check radiation source is measured by the radiation detector 11.

  Further, Sr-90 which is a β-ray source is used as the second check radiation source 143. When the radiation source 11 is irradiated with radiation from the Sr-90 of the second check radiation source 143 by operating the check radiation source mechanism 14, the radiation detector 11 is irradiated with β rays of 2.28 MeV in Y-90 in radiation equilibrium with Sr-90. As shown in FIG. 7, a broad spectrum m2 having no peak appears in most of the measurement range (lower limit dL to upper limit dU) and is measured by the radiation detector 11.

  The radiation monitoring system 80 according to the second embodiment has a peak (check radiation source peak p1) below the lower limit dL value of the measurement range, and a spectrum (check radiation source spectrum) whose pulse height is distributed below the lower limit dL value of the measurement range. The first check radiation source 142 having m1) and the second check radiation source 143 having a spectrum in which the dominant wave height distribution is widely distributed in the measurement range (broad spectrum m2) are used.

  In the radiation monitoring system 80 according to the second embodiment, the measurement unit 15 of the radiation measuring apparatus 1a has the engineering value measurement function described in the first embodiment, and therefore uses the check source peak p1 by the first check source 142. Thus, the same effect as in the first embodiment can be obtained. In other words, the radiation monitoring system 80 according to the second embodiment can minimize the work in the radiation control area in the inspection of the radiation measuring apparatus before the start-up of the plant, and the work in the radiation control area in the inspection during the operation of the plant. In principle, the radiation exposure can be greatly reduced, and, as a whole, the radiation exposure can be greatly reduced, and the reliability of the radiation monitoring system is improved and maintenance work is facilitated by automatically diagnosing calibration conditions that ensure the soundness of detection efficiency. can do.

  Moreover, since the radiation monitoring system 80 of Embodiment 2 always irradiates the radiation detector 11 with radiation from the first check line source 142, the measurement range (from the lower limit dL) corresponding to the monitoring target range of the plant environment. The peak value (channel value) of the check source peak p1 appearing in a region different from the upper limit dU) can be constantly measured. Since the peak value of the check source peak p1 is used as the system gain, the radiation monitoring system 80 according to the second embodiment can perform online automatic diagnosis of the system gain. Therefore, the reliability in the radiation monitoring system can be further improved by performing online automatic diagnosis of system gain regularly or constantly in addition to periodic inspection.

  Even if Am-241, which is a γ-ray source, is used as the first check radiation source 142 and the check radiation source peak p1 is expressed below the lower limit dL of the measurement range CHa1, the background almost increases in the measurement range CHa1. do not do. That is, even if the radiation monitoring system 80 of the second embodiment expresses the check source peak p1 below the lower limit dL of the measurement range CHa1, the measurement sensitivity of the radiation detector 11 in the measurement range CHa1 is set to the check source peak. It can be equivalent to the case where p1 is not expressed. Therefore, the radiation monitoring system 80 according to the second embodiment performs on-line automatic diagnosis of the system gain SG1 without reducing the measurement sensitivity for the measurement target by causing the check source peak p1 to appear below the lower limit dL of the measurement range. realizable. Further, since Sr-90, which is a β-ray source, is used as the second check radiation source 143, the radiation monitoring system 80 according to the second embodiment shields the second check radiation source 143 inside the sampler 12. The shielding thickness of the lead shielding part 63 can be reduced. The radiation monitoring system 80 according to the second embodiment can reduce the shielding thickness of the lead shielding part 63, and thus has an effect of reducing the size of the sampler 12. Therefore, the radiation measuring apparatus 1a can be reduced in size.

Embodiment 3 FIG.
In the first and second embodiments, since the radiation measurement apparatus 1a includes the sampler 12 having a shield that is a large heavy object, the radiation detector 11 and the measurement unit 15 are detached from the radiation measurement apparatus 1a, and the calibration apparatus 2 Carried to the installation site for calibration. In the third embodiment, the measurement object is radiation in the plant area, and the sampler 12 that is a large heavy object is eliminated from the radiation measurement apparatus 1a. In Embodiment 3, since there is no sampler 12, the radiation measuring apparatus 1a becomes light, and the radiation measuring apparatus 1a is removed from the installation location and carried to the installation location of the calibration device 2 for calibration. FIG. 8 is a diagram showing the configuration of the radiation measuring apparatus according to the third embodiment of the present invention. The radiation measurement apparatus 1 a according to the third embodiment includes a radiation detector 11, a check radiation source mechanism 14, a measurement unit 15, and a detector cover 41. The check radiation source mechanism 14 includes a check radiation source support 45, a check radiation source 144, a shutter 145, and a solenoid 147.

  The radiation measuring apparatus 1 a measures the engineering value in a state where the radiation radiated from the check radiation source 144 installed on the check radiation source support 45 of the check radiation source mechanism 14 is shielded by the shutter 145. The radiation measuring apparatus 1a displays the engineering value of the measurement result on the display unit 110 of the measurement unit 15, and turns on the lamp 120 of the measurement unit 15 and alerts the buzzer 130 of the measurement unit 15 when an alarm is issued. ing.

  FIG. 9 is a diagram showing a spectrum of the radiation detector according to the third embodiment of the present invention. In FIG. 9, b represents a background spectrum, n represents a noise peak included in the background spectrum, and m represents a check source spectrum superimposed on the background spectrum by irradiating the radiation of the check source 144. S indicates the index source spectrum at the time of calibration, p indicates the index source peak, dL indicates the lower limit of the measurement range, and dU indicates the upper limit of the measurement range. For example, by using a thin Si semiconductor for the sensor as the radiation detector 11, using Am-241 as a γ-ray source as the index radiation source 210, and using Sr-90 as a β-ray source as the check radiation source 144, The peak p of Am-241 is expressed between the lower limit dL and the upper limit dU of the measurement range as shown in FIG. When the check radiation source mechanism 14 is operated and the shutter 145 is opened, the radiation from the check radiation source 144 is irradiated to the radiation detector 11, and β of 2.28 MeV in Y-90 in radiation equilibrium with Sr-90. The line enters the back substrate of the Si semiconductor. When β rays are incident on the back substrate of the Si semiconductor, the Si semiconductor detects the braking X-rays that are radiated by acting on the Si semiconductor substrate, and a spectrum m over the entire measurement range appears. At the time of calibration, the indicator peak source Am-241 is attached to the front surface of the detector cover 41, and a spectrum peak appears within the measurement range.

  A calibration method of the radiation measuring apparatus 1a will be described. Even at the time of calibration, the radiation detector 11 and the measurement unit 15 are attached to the radiation measurement apparatus 1a, and the calibration work is performed by connecting to the calibration apparatus 2 described in the first embodiment. As described in the first embodiment, the high voltage calibration value HVpr and the high voltage initial value HVin are measured, and the high voltage initial value HVin is self-diagnosis based on the high voltage calibration value HVpr. The voltage calibration value HVpr and the high voltage initial value HVin are stored in the storage device of the calibration device 2.

  Next, Am-241 of the index line source 210 is attached to the front surface of the detector cover 41 with an adhesive tape or the like, and the radiation detector 11 is irradiated with γ-rays from Am-241 which is the index line source 210 to γ of 60 keV. The peak p of the line is expressed, the peak value is obtained as the system gain calibration value SGpr, and the measurement range is set based on the peak value.

  The calibration device 2 calibrates the measurement range lower limit of the measurement unit 15 and the counting operation points of the measurement range upper limit, and sets the measurement range above the measurement range lower limit and below the measurement range upper limit as the measurement range calibration value Apr. The measured range monitor value is set as the measurement range initial value Ain, and the self-diagnosis is performed that the measurement range initial value Ain is within the allowable range on the basis of the measurement range calibration value Apr. The calibration device 2 stores the system gain calibration value SGpr, the measurement range calibration value Apr, and the measurement range initial value Ain in the storage device of the calibration device 2.

Next, the index radiation source 210 is removed and the check radiation source 144 is operated. The calibration apparatus 2 incorporates a net engineering value initial value as a net engineering value initial value as a difference between engineering values within a measurement range initial value Ain before and after irradiation of radiation by the check line source 144, and a net engineering value initial value as a calibration condition. Store in storage. Specifically, the calibration device 2 operates the check radiation source mechanism 14 of the radiation measurement device 1a to irradiate radiation from Sr-90 of the check radiation source 144 to obtain the net initial value Ct1 of the tick radiation source, and performs calibration. Store in the storage device of the device 2. The tick source net initial value Ct1 is a net engineering value initial value.

  When the calibration of the radiation measuring apparatus 1a is completed and a calibration result is obtained, the calibration device 2 transmits a reception request signal indicating the presence of new untransmitted data to the monitoring device 3. When the monitoring device 3 receives the reception request signal, the monitoring device 3 takes in the high voltage initial value HVin and the tick radiation source net initial value Ct1 from the calibration device 2 as the calibration conditions of the radiation measuring device 1a, and updates the fetched data. Store in the storage device of the monitoring device 3 (reference condition acquisition procedure). In addition, the monitoring device 3 resets the transmission of the reception request signal indicating the presence of the untransmitted data in the calibration device 2.

  When the calibration of the radiation measuring apparatus 1a is completed, the radiation measuring apparatus 1a is returned to the installation position and the restoration work is performed, and the check radiation source mechanism 14 is driven to emit radiation (not shown) from the check radiation source 144 to the radiation detector 11. Irradiate. The measurement unit 15 of the radiation measuring apparatus 1a measures the tic line source net value Ctme within the measurement range initial value Ain and the high voltage value HV1 of the high-voltage power supply by the engineering value measurement function. The measurement unit 15 stores the high voltage value HV1 and the tick source net value Ctme of the high voltage power supply in a built-in storage device. The tick source net value Ctme is a net engineering value.

  The monitoring device 3 inputs the high voltage value HV1 and the net value Ctme of the latest high-voltage power supply stored in the storage device built in the measurement unit 15 from the radiation measurement device 1a (acquisition of diagnosis target conditions). Procedure), the high voltage value HV1 and the high voltage initial value HVin, the tick source net value Ctme and the tick source net initial value Ct1 are respectively compared and self-diagnosis is performed within the allowable range (calibration condition diagnosis procedure). The monitoring device 3 displays the diagnosis result on the display device 110, stores the diagnosis result in a built-in storage device, and starts monitoring if there is no problem with the diagnosis result. When there is a problem with the diagnosis result, the monitoring device 3 displays that fact (the diagnosis result has a problem) on the display 110.

  As in the case of the first embodiment, when the monthly inspection of the radiation measuring apparatus 1a is performed until the next periodic inspection of the plant such as the nuclear reactor facility, the spent fuel reprocessing facility, and the radioactive material utilization facility. Perform self-diagnosis to diagnose that the calibration conditions at the time of calibration are reproduced.

  As described above, the radiation monitoring system 80 according to the third embodiment has the same effect as that of the first embodiment and diagnoses the calibration condition from the calibration to the operation with the same check radiation source 144. Since errors due to individual differences can be eliminated, self-diagnosis can be performed with high accuracy.

  In Embodiments 1 and 2, the system gain initial value SGin is included in the calibration conditions that ensure the soundness of the detection efficiency. However, in Embodiment 3, the soundness of the detection efficiency is ensured as described above. The calibration conditions may be the measurement range initial value Ain and the tick source net initial value Ct1.

DESCRIPTION OF SYMBOLS 1a, 1b, 1i ... Radiation measuring apparatus, 2 ... Calibration apparatus, 3 ... Monitoring apparatus, 4a, 4b, 4i ... Transmission cable, 5 ... Transmission cable, 11 ... Radiation detector, 12 ... Sampler, 13 ... Sample to be measured, DESCRIPTION OF SYMBOLS 14 ... Check radiation source mechanism, 15 ... Measurement unit, 22 ... Test cable, 23 ... Test cable, 80 ... Radiation monitoring system, 141, 142, 143, 144 ... Check radiation source, 210 ... Indicator radiation source, p ... Index peak, p1 ... check source peak, m1 ... check source spectrum, m2 ... broad spectrum, Ain ... measurement range initial value, SGin ... system gain initial value, Ct1 ... tic source source initial value (net engineering value initial value) ), SG1... System gain, Ctme... Tick source net value (net engineering value).

Claims (8)

A radiation monitoring system for measuring and managing radiation emitted from a measurement object,
A radiation measuring device installed in a radiation control area and measuring the radiation;
It is installed in a calibration room where the radiation dose is within the radiation control area but is as low as the general area, and stores the calibration conditions and calibration results for calibrating the radiation measuring apparatus, and the calibration conditions and the calibration as required. A calibration device for outputting the results;
A monitoring apparatus for inputting and monitoring the measurement result of the radiation measuring apparatus and diagnosing the soundness of the system by comparing the calibration condition input from the calibration apparatus with the inspection result input from the radiation measuring apparatus; With
The radiation measuring device comprises:
A radiation detector that is detachably disposed and detects the radiation and converts it into an electrical signal;
The detachable arrangement measures the electrical signal of the radiation detector and converts it into a radiation measurement value , which is a measurement value related to the radiation , and compares the radiation measurement value with an alarm setting value to deviate from a predetermined range. A measurement unit that issues an alarm if
A sampler that supports the radiation emitted from the measurement object to be detected at a predetermined detection efficiency by the radiation detector and shields environmental radiation;
A check radiation source mechanism for moving the check radiation source so as to irradiate or shield radiation emitted from the check radiation source incorporated in the sampler to the radiation detector;
When calibrating the radiation measurement apparatus, the radiation detector and the measurement unit moved to the calibration room are connected to each other with a cable, and the measurement unit is connected to the calibration apparatus with a cable,
The calibration device, when calibrating the radiation measurement device , is an index peak value that is the radiation measurement value that appears when the radiation detector is irradiated with radiation from an index radiation source of the same nuclide as the check radiation source. Set a system gain initial value and a measurement range initial value that is an initial value of a measurement range to be managed based on the system gain, and stores the system gain initial value and the measurement range initial value in the storage device built in as the calibration condition,
The monitoring device is a check radiation source peak value that is the radiation measurement value that appears when the radiation measurement device irradiates the radiation detector with radiation from the check radiation source during inspection of the radiation measurement device. To obtain a system gain and a measurement range set based on the check source peak value, and each of the set system gain and measurement range includes the system gain initial value and the measurement range initial value. A radiation monitoring system characterized by automatically diagnosing that it is within a standard allowable range. The check radiation source mechanism is further equipped with another check radiation source so as to irradiate the radiation detector with radiation emitted from the check radiation source during a monitoring operation, and the other check line during the inspection. Irradiating the radiation detector with radiation emitted from a source;
The check radiation source has a spectrum having a peak below the lower limit value of the measurement range and a pulse height distribution below the lower limit value of the measurement range,
The other check-ray source is the wave height distribution is widely distributed within the measurement range, and has a larger spectrum than peak value peak value by the checking-ray source within the measurement range,
2. The radiation according to claim 1, wherein the check radiation source peak value is measured when the radiation measuring apparatus irradiates the radiation detector with radiation from the check radiation source during the monitoring operation. Monitoring system.   The monitoring device acquires a measurement result of a check source peak value that appears when the radiation detector is irradiated with radiation from the check source during a monitoring operation, and sets based on the check source peak value The radiation monitoring system according to claim 2, wherein the measured system gain is diagnosed.   4. The radiation monitoring system according to claim 2, wherein the check radiation source has a nuclide of Am-241 and the other check radiation source has a nuclide of Sr-90. A radiation monitoring system for measuring and managing radiation emitted from a measurement object,
A radiation measuring device installed in a radiation control area and measuring the radiation;
It is installed in a calibration room where the radiation dose is within the radiation control area but is as low as the general area, and stores the calibration conditions and calibration results for calibrating the radiation measuring apparatus, and the calibration conditions and the calibration as required. A calibration device for outputting the results;
A monitoring apparatus for inputting and monitoring the measurement result of the radiation measuring apparatus and diagnosing the soundness of the system by comparing the calibration condition input from the calibration apparatus with the inspection result input from the radiation measuring apparatus; With
The radiation measuring device comprises:
A radiation detector that detects the radiation and converts it into an electrical signal;
The electrical signal of the radiation detector is measured and converted into a radiation measurement value that is a measurement value related to the radiation , and an alarm is issued when the radiation measurement value and the alarm set value are compared and deviated from a predetermined range. A measuring unit to
A check radiation source mechanism that irradiates or shields the radiation detector with radiation emitted from a check radiation source incorporated in the radiation measuring apparatus;
When calibrating the radiation measuring apparatus, the radiation measuring apparatus moved to the calibration chamber is connected to the calibration apparatus with a cable,
The calibration apparatus measures an index peak value and a spectrum that are the radiation measurement values that are expressed when the radiation detector is irradiated with radiation from an index radiation source when the radiation measurement apparatus is calibrated, and the index set the measuring range initial value is the initial value of the system gain initial value and the measurement range to be managed based on the peak value, the difference in count rate of the spectrum within the measurement range before and after irradiation by the check-ray source A net engineering value as a net engineering value initial value, and the net engineering value initial value and the measurement range initial value are stored in a built-in storage device as the calibration condition,
When the radiation measuring apparatus is inspected, the monitoring apparatus irradiates the radiation detector with radiation from the check radiation source , and a spectrum that is the radiation measurement value expressed by the irradiation. To measure and obtain a net engineering value that is a difference in the count rate of the spectrum within the set measurement range initial value before and after irradiation of radiation from the check line source, and the net engineering value is the net engineering value A radiation monitoring system characterized by automatically diagnosing that it is within an allowable range based on an initial value.   6. The radiation monitoring system according to claim 5, wherein the index radiation source has a nuclide of Am-241, and the check radiation source has a nuclide of Sr-90. The radiation measuring device is connected to the monitoring device via a first transmission cable;
The calibration device is connected to the monitoring device via a second transmission cable;
The radiation monitoring system according to claim 1, wherein the first transmission cable and the second transmission cable are optical cables. A method for diagnosing calibration conditions in a radiation monitoring system according to any one of claims 1 to 7,
Reference condition acquisition procedure for storing the calibration condition stored in the calibration apparatus when the radiation measurement apparatus is calibrated, as a reference calibration condition in the monitoring apparatus;
A diagnostic object condition acquisition procedure for storing the calibration condition set in the radiation measurement apparatus at the time of inspection of the radiation measurement apparatus in the monitoring apparatus as a measurement calibration condition;
And a calibration condition diagnosis procedure for automatically diagnosing that the measurement calibration condition is within an allowable range based on the reference calibration condition.

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