JP2007108141A - Radiation monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation monitoring device capable of improving operational efficiency, working efficiency during inspection, or the like a nuclear power plant by securely preventing an incorrect detection of monitoring object. <P>SOLUTION: The radiation monitoring device 10 includes a specific γ-ray detection means 11 detecting only the γ-ray from nuclides to be a radiation source of a high-dose work, a gross γ-ray detection means 12 detecting the gross of the γ-ray amounts from the emission nuclides accompanied by an event to be a monitoring object and the nuclear species to be the radiation source of the high-dose work, and a decision device 15 excluding the monitoring of radiation with the gross γ-ray measurement value from the gross γ-ray detection means 12 depending on the γ-ray measurement value from the specific γ-ray detection means 11, and detects the event of the monitoring object by the decision device 15. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radiation monitoring technique used in facilities such as a nuclear power plant and a chemical processing facility, and more particularly to a radiation monitoring apparatus that monitors a radiation measurement value to be monitored and detects an abnormal event to be monitored.

  In nuclear power plant facilities and the surrounding environment, radiation monitoring of radiation intensity and water and air radioactivity concentrations from monitored objects, monitored devices and equipment, and monitored areas (hereinafter referred to as monitored objects) within the facility. Various radiation monitoring devices are installed for the purpose (see, for example, Patent Document 1). Such a radiation monitoring apparatus generally includes a radiation detector and a monitor device, and can detect an abnormal event of the monitoring target by monitoring a radiation measurement value emitted from the monitoring target.

Conventional radiation monitoring equipment measures γ-rays, which are less attenuated than α-rays and β-rays, from radiation emitted from radionuclides due to abnormal events to be monitored, and measures the gross amount of this γ-dose. The monitoring target is monitored using the value. Specifically, as a result of abnormal events to be monitored, the gross measured value of gamma radiation released from radionuclides and the radionuclides that serve as radiation sources for high-dose work during regular inspections increased. It is used for radiation monitoring.
Japanese Patent Laid-Open No. 4-125489

  A conventional radiation monitoring apparatus monitors the presence / absence of an abnormality in a monitoring target by measuring the gloss value of the emitted γ dose.

  Among γ-rays, there are γ-rays in various energy bands. When γ-ray dose is measured as a gross value, γ-rays generated from unmonitored events are measured together with γ-rays at various energy levels. Therefore, there is a possibility that an event other than the monitoring target is erroneously detected.

  If an event other than the monitoring target is erroneously detected, it is determined that an abnormal event has occurred despite the fact that the monitoring target is normal. There was a problem that led to a decrease in work efficiency.

  The present invention has been made in consideration of the above-mentioned circumstances, and radiation monitoring that can reliably prevent erroneous detection of a monitoring target and improve the operational efficiency of a nuclear power plant and the work efficiency at the time of inspection, etc. An object is to provide an apparatus.

  In order to solve the above-described problem, the radiation monitoring apparatus according to the present invention includes, as described in claim 1, specific γ-ray detection means for detecting only γ-rays from nuclides serving as a radiation source for high-dose work, , Gamma ray measurement means for detecting radiated nuclides associated with events to be monitored, and gamma radiation from nuclides that are the source of high-dose work, and γ-ray measurement values from specific γ-ray detection means And a determination device that excludes radiation monitoring based on the gross γ-ray measurement value from the gross γ-ray detection means. The determination device detects an event to be monitored.

  In addition, in order to solve the above-described problem, the radiation monitoring apparatus according to the present invention detects specific γ-rays that detect only γ-rays from nuclides that are radiation sources for high-dose work, as described in claim 2. Means, a gamma ray detection means for detecting a gamma radiation dose from a nuclide that is a source of radiation for high-dose work, and a gamma ray from both the gamma ray detection means A determination device that inputs a line measurement signal and simultaneously monitors both γ-ray measurement values, and detects an event to be monitored by this determination device.

  Furthermore, in order to solve the above-described problem, the radiation monitoring apparatus according to the present invention detects specific γ-rays that detect only γ-rays from nuclides that are radiation sources for high-dose work, as described in claim 3. Measured by the means, the detected nuclides associated with the events to be monitored, and the gross γ-ray detection means for detecting the γ-ray gross from the nuclides that are the source of the high-dose work, and both the γ-ray detection means A difference value calculation means for calculating a difference value of the measured γ-ray values, and a determination means for determining radiation monitoring from the magnitude of the difference value from the calculation means, and the event to be monitored is determined by the determination means. It is something to detect.

  Furthermore, in order to solve the above-described problem, the radiation monitoring apparatus according to the present invention detects γ-rays from emission nuclides accompanying an event to be monitored as described in claim 4. Radiation monitoring is performed from the detection means, the calculation means for calculating the time change rate of the γ-ray measurement value measured by the γ-ray detection means, and the magnitude of the time change rate of the γ-ray measurement value output from the calculation means. A judging means for judging, and the judging means detects an event to be monitored.

  Still further, in order to solve the above-described problem, the radiation monitoring apparatus according to the present invention detects γ-rays from emission nuclides accompanying an event to be monitored as described in claim 5. A detecting means, a calculating means for multiplying the measured γ-ray value measured by the γ-ray detecting means by N, and performing a first-order lag process for limiting the radiation dose to the environment to a specified value or less, and output from the calculating means And determining means for determining radiation monitoring from the calculated value subjected to the first-order delay processing, and the event to be monitored is detected and detected by the determining means.

  On the other hand, in order to solve the above-described problem, the radiation monitoring apparatus according to the present invention detects γ-rays from a plurality of emission nuclides accompanying an event to be monitored, as described in claim 6. A ray detection means, a pulse height discrimination means for counting γ rays of energy levels for each emission nuclide by pulse height discrimination based on a γ ray measurement value from the γ ray detection means, and a discharge counted by the pulse wave discrimination means And determining means for determining radiation monitoring from the ratio of the count value for each nuclide, and the event to be monitored is detected by the determining means.

  On the other hand, in order to solve the above-described problem, the radiation monitoring apparatus according to the present invention detects γ-rays from emission nuclides associated with an event to be monitored, as described in claim 7. Means and a determination means for determining radiation monitoring from the magnitude of the γ-ray measurement value measured by the γ-ray detection means. The determination means is based on an operation mode signal from the plant or a monitoring target device or apparatus. The operation status signal can be input, and the radiation monitoring is set to be automatically switched between valid and excluded according to the input signal, and the event to be monitored is detected by the determination means.

  Furthermore, in order to solve the above-described problems, the radiation monitoring apparatus according to the present invention detects γ-rays from emission nuclides associated with events to be monitored, as described in claim 8. Means, a setting value selection means for automatically switching the monitoring set value in accordance with an operation mode signal from the plant or an operation status signal from the monitored device or apparatus, and a γ-ray measurement value from the γ-ray detection means. It has a judging means for judging radiation monitoring in comparison with the monitoring set value from the set value selecting means, and detects the event to be monitored by the judging means.

  In addition, in order to solve the above-described problem, the radiation monitoring apparatus according to the present invention detects specific γ rays only from nuclides serving as a radiation source for high-dose work as described in claim 9. Measured by detection means, gross γ-ray detection means for detecting the nuclides emitted from the nuclide that is the source of high-dose work, and the specific γ-ray detection means. A set value calculating means for calculating a monitoring set value from the measured γ-ray measured value, and comparing the gross γ-ray measured value from the gross γ-ray detecting means with the monitoring set value from the set value calculating means for radiation monitoring. A judging means for judging, and the judging means detects an event to be monitored.

  Furthermore, in order to solve the above-described problem, the radiation monitoring apparatus according to the present invention includes, as described in claim 10, a γ-ray distribution measuring apparatus that measures a γ-ray distribution position and intensity in a monitoring target space; A calculation determination means for calculating a time change rate of the γ-ray distribution position or the γ-ray distribution intensity from the γ-ray spatial distribution information obtained from the γ-ray distribution measuring apparatus and determining radiation monitoring; Is used to detect an event to be monitored.

  Furthermore, in order to solve the above-described problem, the radiation monitoring apparatus according to the present invention provides a γ-ray detection unit that detects γ-rays from emission nuclides in the monitoring target area around the fuel pool as described in claim 13. An underwater camera provided in the fuel pool, an image processing means for image processing of a camera image from the underwater camera and calculating a moving speed of the monitoring object, and a monitoring object processed by the image processing means Discriminating means for discriminating underwater work and drop accidents during normal regular inspection from the moving speed of the vehicle, and judging means for judging the validity or invalidity of radiation monitoring in the monitored area based on the discrimination output from the discrimination judging means The event to be monitored is detected by this determination means.

  Moreover, in order to solve the above-described problem, the radiation monitoring apparatus according to the present invention includes, as described in claim 15, radiation detection means for detecting γ-ray intensity emitted from a metal radioactive material such as stainless steel, and the like. A means for predicting the scattering contribution component to the γ-ray energy emitted from the emission nuclide peculiar to the event to be monitored from the γ-ray intensity of the radioactive material measured by the radiation detector; and The gamma ray measurement signal from the radiation detector is monitored with respect to the predicted value that has been predicted, and the judgment means for judging the radiation monitoring is included, and the event to be monitored is detected by the judgment means.

  In the radiation monitoring apparatus according to the present invention, it is possible to accurately and effectively detect an event to be monitored and avoid erroneous detection of an event that is not monitored, so that the operational efficiency, inspection, etc. of the nuclear power plant can be avoided. Work efficiency can be improved.

  Embodiments of a radiation monitoring apparatus according to the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is a system block configuration diagram schematically showing a first embodiment of a radiation monitoring apparatus according to the present invention.

  This radiation monitoring device 10 shows an example applied to a core coolant temperature measuring device that monitors a core coolant of a nuclear power plant. The radiation monitoring apparatus 10 includes specific γ-ray detection means 11 that detects only γ-rays in a specific energy band emitted from emission nuclides of events to be monitored, and gloss that detects gloss values of γ-rays in various energy bands. The core coolant having the γ-ray detection means 12 contains a radionuclide, and radiation is emitted from a radiation source of this radionuclide.

  The specific γ-ray detection means 11 selectively detects γ-rays in the specific energy level or energy region from the radionuclide, that is, specific γ-rays from the nuclide that is the source of the high-dose work during the regular inspection. Outputs the measurement signal a and is composed of a γ-ray detector such as a Cd-Te semiconductor detector or a γ-ray detection circuit. There are various measurement methods for selectively measuring only γ rays (specific energy bands or γ rays in energy levels) from specific nuclides. For example, depending on the output pulse height from a Cd-Te semiconductor detector, There is a technique for discriminating and measuring gamma rays from specific nuclides. The specific energy level may be a plurality of energy levels instead of a single energy level.

  The gross γ-ray detection means 12 outputs the gross γ-ray measurement signal b of the gross energy band from the emission nuclide associated with the event to be monitored and the emission nuclide used as the radiation source for the high-dose work during the periodic inspection. It is composed of a γ-ray detector or a γ-ray detection circuit.

  The gamma ray measurement signal a having a specific energy level from the specific radionuclide detected by the specific gamma ray detection unit 11 is input to the specific determination unit 13. A specific monitoring setting signal c set in advance is input to the specific determination means 13. The specific monitoring setting signal c is a signal of a specific monitoring setting value predicted in advance by an analysis unit (not shown) or a prediction setting unit.

  The specific determination unit 13 compares the specific energy level or energy region γ-ray measurement signal a from the specific γ-ray detection unit 11 with the specific monitoring setting signal c, and the γ-ray measurement value exceeds the specific monitoring setting value. When the specific monitoring set value c is out of the setting range, the monitoring exclusion signal d is output to the gloss determination means 14. When the magnitude of the γ-ray measurement signal a (γ-ray measurement value) is within the setting range of the specific monitoring setting signal c or below the specific monitoring installation value of the specific monitoring setting signal c, the monitoring exclusion signal d is not output.

  On the other hand, the gross determination unit 14 receives the gross γ-ray measurement signal b from the gross γ-ray detection unit 12, compares the gross γ-ray measurement signal b with the gross monitoring setting signal e, and determines the gross γ-ray measurement signal b. When the signal level exceeds the level of the gross monitoring setting signal e or is outside the set value of the setting signal e, an alarm signal f is output.

  When the monitoring exclusion signal d is input from the specific determination unit 13 to the gloss determination unit 14, the output of the alarm signal f is stopped. The gloss determination means 14 includes, for example, a first-stage comparator that compares the gross γ-ray measurement signal b and the gross monitoring setting signal e, an output signal from the first-stage comparator, and monitoring exclusion from the specific determination means 13. A second stage comparator for comparing the signal d is provided connected in series, and when the monitoring exclusion signal d is input to the second stage comparator, the output of the alarm signal f is stopped.

  The specific γ-ray detection means 12 and the gross γ-ray detection means 12 constitute a determination device 15, and this determination device 15 receives the measured value from the gross γ-ray detection means 12 based on the γ-ray measurement value from the specific γ-ray detection means 11. Configured to exclude radiation monitoring by gross gamma ray measurements. This determination device 15 detects an event to be monitored and prevents erroneous detection of an event other than the monitoring target, for example, erroneously detecting a high-dose operation as an accident event or an abnormal event.

  Next, the operation of the radiation monitoring apparatus 10 will be described.

  An example in which the core coolant is monitored using this radiation monitoring apparatus 10 will be described. The radiation monitoring apparatus 10 detects only specific energy levels or specific energy gamma rays from a specific radionuclide that serves as a radiation source for high-dose work during regular inspection by the specific gamma ray detection means 11, and detects the specific gamma detected. The line measurement signal a is output to the specific determination means 13.

  On the other hand, in the gross γ-ray detection means 12 of the determination device 15, gross γ-rays from the emission nuclides accompanying the event of the core coolant to be monitored and the radiation nuclides that serve as the radiation source for high-dose work during regular inspection ( Γ-rays at all energy levels) are measured and output to the gloss determination means 14 as a gross γ-ray measurement signal b.

  The gloss determination means 14 is used when the signal level of the gross γ-ray measurement signal b exceeds a preset signal level of the gross monitoring setting signal e, or when it is outside the range of the signal setting value of the gross monitoring setting signal e. The alarm signal f is output to generate an alarm.

  At this time, when the monitoring exclusion signal d is input from the specific determination unit 13 to the gloss determination unit 14, the determination device 15 stops the output of the alarm signal f and stops the output of the alarm signal f from the gloss determination unit 14. I'm damned.

  The specific determination means 13 receives a specific γ-ray measurement signal a of a specific energy level or energy region from the specific γ-ray detection means 11, and this specific γ-ray measurement signal a is a signal of a specific monitoring set value by the specific determination means 13. When this specific monitoring set value c is exceeded or outside the set value range, a monitoring exclusion signal d is output to the gloss determination means 14 and an alarm signal f is output from the gloss determination means 14 Stop the output so that it does not.

  Specifically, when the abnormal event (accident event) to be monitored is, for example, γ rays in a high energy region, the gross value of γ rays detected by the gross γ ray detection means 12 becomes large and large gross γ rays. The measurement signal b is input to the gloss determination means 14. On the other hand, at this time, the gross monitoring set value signal e input to the gloss determination means 14 is a predetermined constant value. When the gross γ-ray measurement signal b exceeds the gross monitoring setting signal e, the determination device 15 An alarm signal f is output from the gloss determining means 14.

  However, even if the gross γ-ray measurement signal b exceeds the gross monitoring setting signal e, the output of the alarm signal f is stopped when the monitoring exclusion signal d is input to the gross judgment means 14 from the specific judgment means 13.

  By the way, the specific γ-ray detection means 11 detects γ-rays in a specific energy region (energy level), that is, specific γ-rays from nuclides that are sources of high-dose work. If the line is a gamma ray with a low energy level, if the event to be monitored is an abnormal event or an accident event, for example, the output of a gamma ray with a high energy level rises, and the gross gamma ray detection means 12 The gross value of γ-rays detected at 1 increases. However, since the γ-ray of the specific energy level detected by the specific γ-ray detection unit 11 hardly changes, the monitoring exclusion signal d is not output from the specific determination unit 13 to the gloss determination unit 14.

  In this case, an alarm signal f is output from the gloss determination means 14 due to the rising change in the gross γ-ray detected by the gross γ-ray detection means 12, and the monitored object is an abnormal event or an accident event. Can be informed.

  In addition, even if the monitoring target is not an accident event or abnormal event, pollutants that emit gamma rays in a specific energy range (energy level) are included in the monitoring target, for example, core coolant, due to general work Both the signal level of the specific γ-ray measurement signal a detected by the specific γ-ray detection means 11 and the signal level of the gross γ-ray measurement signal b detected by the gross γ-ray detection means 12 are both increased.

  However, at this time, the monitoring exclusion signal d is output from the specific determination unit 13 due to an increase in the signal level of the specific γ-ray measurement signal a input to the specific determination unit 13. Since the monitoring exclusion signal d is input to the gloss determination means 14, the warning signal f is not output from the gloss determination means 14.

  In this way, the specific γ-ray detection means 11 capable of measuring only γ-rays from nuclides that serve as radiation sources for high-dose work during a regular inspection of a nuclear power plant, that is, only γ-rays in a specific energy level or energy region. When the signal level of the γ-ray measurement signal a of the specific energy level detected by the specific γ-ray detection means 11 exceeds the signal c of the specific monitoring set value set in advance, the determination is made The monitoring exclusion signal d can be output from the means 13 to the gloss determination means 14, and the monitoring of the monitoring target by the gloss determination means 14 can be excluded.

  In this radiation monitoring apparatus 10, it is possible to reliably and accurately detect an accident event or abnormal event to be monitored and an alarm signal output from the gloss determination means 14. In addition, in high-dose work during periodic inspections that are not monitored, by outputting the monitoring exclusion signal d from the specific determination means 13, it becomes possible to reliably avoid erroneous detection of events that are not monitored. It is possible to improve the operational efficiency of nuclear power plants and the work efficiency of inspections.

[Second Embodiment]
FIG. 2 is a configuration diagram of a system block schematically showing a second embodiment of the radiation monitoring apparatus according to the present invention.

  In describing the radiation monitoring apparatus 10A of the second embodiment, the same components as those of the radiation monitoring apparatus 10 shown in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The radiation monitoring apparatus 10A shown in FIG. 2 detects specific γ-rays that can detect only γ-rays (specific energy bands or γ-rays at an energy level) from radionuclides that serve as radiation sources for high-dose work during regular inspection. Means 11, gross γ-ray detection means 12 capable of detecting emission nuclides associated with events to be monitored and nuclides serving as radiation sources for high-dose work during regular inspection, and specific γ-rays A γ-ray measurement signal a in a specific energy band (energy level) from the detection means 11 is input, the γ-ray measurement signal a is compared with a specific monitoring set value c, and the signal level of the γ-ray measurement signal a is set to a specific monitoring setting. A specific determination means for outputting an alarm output signal g when the signal level of the signal c is exceeded, and a gross γ-ray measurement signal b from the gross γ-ray detection means 12 are input, and the gross γ-ray measurement signal b is gross monitored. Measured signal e and ratio When the gross γ-ray measurement signal b exceeds the gross monitoring set value signal e, the gross judgment means 14 for outputting the warning output signal h and the warning output signals g and h from the judgment means 13 and 14 are input. And an alarm generating means 16 for outputting an alarm i.

  The monitoring generator 16 includes an AND circuit and an alarm device. When both the alarm output signal g from the specific determination device 13 and the gloss output signal h from the gloss determination device 14 are input to the AND circuit, an output is output to the alarm device. A signal is sent and an alarm is issued.

  The radiation monitoring apparatus 10 </ b> A includes a determination device 17 including a specific determination unit 13, a gloss determination unit 14, and an alarm generation unit 16, and this determination device 17 is a γ-ray measurement signal from both γ-ray detection units 11 and 12. a and b are input to the specific determination means 13 and the gloss determination means 14, and when the alarm generation means 16 inputs the output signals g and h from both determination means 13 and 14 simultaneously, the output of the alarm signal i is stopped. It has become.

  This radiation monitoring apparatus 10A is accompanied by specific γ-ray detection means 11 capable of measuring only γ-rays in a specific energy band from nuclides serving as radiation sources for high-dose work during regular inspections, and accompanying events to be monitored. The gamma ray detection means 12 capable of measuring the emission nuclides and the gamma rays of the gross from the nuclides that are the source of high-dose work during regular inspection, and the specific detected by both γ-ray detection means 11 and 12 When the γ-ray detection value and gross γ-ray detection value exceed the monitoring set value, an alarm i is output from the determination device 17, so that the event to be monitored (abnormal event or accident event) can be detected accurately and reliably. can do.

  Under high-dose work during regular inspections that are not monitored, γ-rays only in a specific energy band are measured, but the specific γ-ray detection means 11 does not detect γ-rays at energy levels other than the specific energy band. . At this time, the alarm position signal is not output from the determination device 17, and thus it is possible to avoid erroneous detection of high-dose work during regular inspection that is not monitored, and the operational efficiency, inspection, etc. of the nuclear power plant Work efficiency can be improved.

[Third Embodiment]
FIG. 3 is a system block diagram schematically illustrating a third embodiment of the radiation monitoring apparatus according to the present invention.

  In describing the radiation monitoring apparatus 10B of the third embodiment, the same components as those of the radiation monitoring apparatus 10 shown in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The radiation monitoring apparatus 10B shown in FIG. 3 includes a specific γ-ray detection unit 11 capable of detecting only a specific energy band or energy level γ-ray from a nuclide that is a radiation source for high-dose work during regular inspection, and monitoring. From the gamma ray detection means 12 capable of detecting the emission nuclides accompanying the target event and the gamma radiation dose from the nuclides that are the source of high-dose work during the regular inspection, and the specific γ-ray detection means 11 The calculation means 18 for calculating the difference between the specific γ-ray measurement signal a and the gross γ-ray measurement signal b from the gross γ-ray detection means 12 and the γ-ray measurement signals a and b calculated by the calculation means 18 And a determination unit 19 to which a difference value signal j is input. When the difference value signal j exceeds the difference monitoring set value signal k, the determination unit 19 outputs an alarm signal f to generate an alarm. It has become.

  The difference monitoring setting value signal k is a difference monitoring setting signal set in advance by a pre-analysis or prediction setting unit of an analysis unit (not shown).

  This radiation monitoring apparatus 10B can detect and detect only a specific energy band or energy level γ-ray (specific γ-ray) used as a radiation source for high-dose work during regular inspection by the specific γ-ray detection means 11. The specific γ-ray measurement signal a is output to the calculation means 18.

  On the other hand, the gross γ-ray detection means 12 can detect and detect the released nuclides accompanying the events to be monitored and the γ-rays of gross from the nuclides that are the source of high-dose work during regular inspection. The gross γ-ray measurement signal b is output to the difference value calculation means 18.

  The difference value calculation means 18 is inputted with γ-ray measurement signals a and b from both γ-ray detection means 11 and 12, respectively, and the difference value (| a−b |) of both input γ-ray measurement signals a and b. ) Is calculated. When the calculated difference value signal j exceeds the difference monitoring set value signal k, the determination means 19 outputs an alarm signal f to generate an alarm.

  In this radiation monitoring apparatus 10B, when the event of the monitoring target (monitoring object, device and apparatus) is an abnormal event or an accident event, the gross value of the emitted γ-ray (the γ-ray in the entire energy band) is detected. The signal level of the gross γ-ray measurement signal b from the γ-ray detection means 12 increases.

  On the other hand, the specific γ-ray detection means 11 for detecting γ-rays in a specific energy band detects only γ-rays at a specific energy level from the nuclide that is the source of high-dose work during regular inspection. The signal level of the specific γ-ray measurement signal a does not increase.

  For this reason, if the event to be monitored is an abnormal event or an accident event, the difference value calculated by the calculation means 18 becomes large, and this difference value is sent to the determination means 19 to set a difference monitoring setting value set in advance. Compared with When the difference value exceeds the difference monitoring set value, the determination means 19 outputs an alarm signal f and generates an alarm.

  Therefore, when the event to be monitored is an abnormal event or an accident event, the abnormal event or the accident event can be reliably detected.

  On the other hand, if the specific γ-ray detection means 11 detects only γ-rays in a specific energy band from the nuclide that is the source of the high-dose work during the regular inspection, the signal level of the specific γ-ray measurement signal a is an accident event or abnormality. It rises even if it is not an event. At this time, since the gross γ-ray detection means 12 detects the gross value of γ-rays (γ rays in the entire energy band), the signal level of the gross γ-ray measurement signal b also increases.

  However, since the difference value | a−b | between the two γ-ray measurement signals a and b input from the two γ-ray detection means 11 and 12 to the calculation means 18 hardly changes, the difference value exceeds the difference monitoring set value. There is no turning. For this reason, the warning signal f is not output from the determination means 19.

  The radiation monitoring apparatus 10B shown in the third embodiment can detect an event to be monitored (an abnormal event or an accident event), while performing a high-dose operation during a regular inspection that is not a monitoring target, It is possible to reliably avoid false detection of an accident event. Therefore, it is possible to improve the operational efficiency of the nuclear power plant and the work efficiency of inspections.

[Fourth Embodiment]
FIG. 4 is a system block diagram schematically showing a fourth embodiment of the radiation monitoring apparatus according to the present invention.

  The radiation monitoring apparatus 10C shown in this embodiment includes a γ-ray detection unit 21 that can detect γ-rays from an emission nuclide accompanying an event to be monitored, and a γ detected by the γ-ray detection unit 21. The calculation means 22 to which the line measurement signal l is input, the time change rate of the γ-ray measurement value is calculated by the calculation means 22, and the determination means 23 to which the calculated time change rate signal m of the γ-ray measurement value is input. The determination means 23 compares the time change rate value of the γ-ray measurement value with the monitoring set value, and outputs a warning signal f and generates an alarm if the time change rate value exceeds the monitoring set value. It is supposed to let you.

  The γ-ray detection means 21 detects γ-rays from emission nuclides associated with the event to be monitored (accident event or abnormal event), and the rate of time change of the γ-ray measurement value specific to the event to be monitored Is measuring.

  The time change rate of the γ-ray measurement value peculiar to the event to be monitored is calculated by the calculation means 22 for calculating the γ-ray measurement signal inputted to the γ-ray detection means 21, and this calculated γ-ray measurement value is calculated. The value of the time change rate, that is, the time change rate value peculiar to the accident event or abnormal event to be monitored is compared with the monitor set value by the judging means 23, and if it exceeds the monitor set value, the alarm signal f is output. It is possible to detect that the event to be monitored is an abnormal event or an accident event.

  Monitoring setting values are pre-analyzed by an analysis means (not shown) or event-specific monitoring setting values are set in advance by a prediction setting means, and a monitoring setting value signal specific to a preset event (abnormal event or accident event) n is input to the determination means 23.

  In the radiation monitoring apparatus 10C shown in FIG. 4, the γ-rays emitted from the emission nuclides accompanying the event to be monitored are detected by the γ-ray detection means 21, and the detected γ-rays are detected by the γ-ray measurement signal l. Is input to the calculation means 22, the time change rate of the γ-ray measurement value peculiar to the event to be monitored is calculated by the calculation means 22, and the time change rate signal m of the γ-ray measurement value is output to the determination means 23. ing.

  The time change rate signal m of the γ-ray measurement value input to the determination unit 23 is compared with the event-specific monitoring set value signal n, and when the value of the time change rate of the γ-ray measurement value exceeds the monitoring set value, An alarm signal f is output to generate an alarm.

  In this radiation monitoring apparatus 10C, the γ-ray detection means 21 measures γ-rays from the emission nuclide accompanying the event to be monitored, and the calculation means 22 calculates the time change rate of the γ-ray measurement values. The time change rate value of the obtained γ-ray measurement value is calculated and compared with the monitor setting value specific to the event to be monitored by the calculation means 23, and the time change rate value of the γ-ray measurement value is set as the monitor set value. When it exceeds the upper limit, the alarm signal f can be output.

  The radiation monitoring apparatus 10C can detect the time change rate of γ-rays peculiar to the event to be monitored, and the detected time change rate of γ-rays is set to a preset monitoring setting value (this monitoring setting value). Is a preset value of γ-ray that is specific to the event to be monitored.) Compared to the above, an alarm is output when it exceeds, so the event to be monitored can be reliably detected, High-dose work during regular inspections that are not subject to monitoring can avoid false detections that determine abnormal events or accident events, and can improve the operational efficiency of nuclear power plants and work efficiency such as inspections. it can.

[Fifth Embodiment]
FIG. 5 is a system block diagram schematically showing a fifth embodiment of the radiation monitoring apparatus according to the present invention.

  In describing the radiation monitoring apparatus 10D of the fifth embodiment, the same components as those of the radiation monitoring apparatus 10C of the fourth embodiment are denoted by the same reference numerals and description thereof is omitted.

  The radiation monitoring apparatus 10D shown in FIG. 5 includes a γ-ray detection unit 21 that can detect γ-rays from emission nuclides accompanying an event to be monitored, and a γ-ray output from the γ-ray detection unit 21. The calculation means 25 for inputting the measurement signal l, multiplying the γ-ray measurement value by N, and performing the first-order lag processing, and the determination means 26 for receiving the signal o of the calculated value subjected to the first-order lag processing from the calculation means 25 The determination means 26 outputs an alarm signal f to generate an alarm when the calculated value subjected to the first-order delay processing exceeds the monitoring set value.

  The calculation means 25 includes an amplifier and a first-order lag processor connected in series, and the γ-ray measurement value detected by the γ-ray detection means 21 is amplified N times by the amplifier and then the first-order lag processor Delayed. The calculated value of the γ-ray measurement subjected to the first-order lag process is output to the determination means 26. The calculation means 25 has a first-order lag time constant, and this first-order lag time constant is an analysis means (not shown) to a value that can limit the amount of released nuclides released to the environment by the event to be monitored below the emission limit amount. Determined by analysis evaluation by

  The calculation means 25 compares the calculated value of the γ-ray, which has been first-order processed by the first-order lag processor having a first-order lag time constant, with the monitoring setting value which does not adversely affect the environment by the determination means 26, and calculates the monitoring setting value. When exceeding, an alarm signal f is output and an alarm is generated. The alarm set value signal p input to the determination unit 26 is a value set in advance by preanalysis by an analysis unit (not shown).

  This radiation monitoring apparatus 10D detects γ-rays from emission nuclides accompanying an event to be monitored by the γ-ray detection means 21 and causes the calculation means 25 to input the detected γ-ray measurement signal l. The calculation means 25 multiplies the γ-ray measurement value detected by the γ-ray detection means 21 by N, and causes the determination means 26 to output the calculated value subjected to the first-order lag processing.

  The determination unit 26 outputs an alarm signal f and generates an alarm when the calculated value subjected to the first-order delay processing by the calculating unit 25 exceeds the monitoring set value.

  The radiation monitoring apparatus 10D can detect an event to be monitored by γ-ray detection by the γ-ray detection means 21, and further performs a first-order lag process on the γ-ray measurement value by the calculation means 25, and sets the time constant of this first-order lag process to the environment. By setting in consideration of the impact on the environment, the amount of released nuclides released into the environment can be limited to the post-release regulated amount or less for events to be monitored. In addition, it is possible to detect events to be monitored, avoid false detection of high-dose work during regular inspection, and improve operational efficiency of nuclear power plants, work efficiency such as inspection.

[Sixth Embodiment]
FIG. 6 is a system block diagram schematically illustrating a sixth embodiment of the radiation monitoring apparatus.

  This radiation monitoring apparatus 10E includes a γ-ray detector 30 as γ-ray detection means. The γ-ray detector 27 outputs a pulse signal having a wave height corresponding to the γ-ray energy (energy level) of a plurality of emission nuclides accompanying an event to be monitored.

The radiation monitoring apparatus 10E includes a γ-ray detector 27 that outputs a pulse signal having a wavelength corresponding to each γ-ray energy of γ-rays emitted from a plurality of nuclides associated with an event to be monitored, and this γ-ray detection. the pulse height discriminator pulse signals from vessel 27, the pulse height discriminator 28 which counts each radionuclide, judging means for inputting the pulse height at discriminator 28 is counted for each nuclide count value a ₁ to a _n and a 29, determination means 29, the ratio of the count value _a 1 to a _n input from the pulse height discriminator 28 calculates the ratio of the count value _a 1 to a _n has exceeded the monitoring setting value In this case, an alarm signal f is output to generate an alarm.

The calculation of the ratio of the count value A ₁ to A _n can be carried out in pulse-height discriminator means 28.

The radiation monitoring apparatus 10E outputs a pulse signal having a wave height corresponding to the γ-ray energy of a plurality of emission nuclides accompanying the event to be monitored by the γ-ray detector 27, and the pulse signal from the γ-ray detector 27. the pulse height discriminator 28 to q, are counted for each nuclide, a counted ratio of the count value a ₁ to a _n of each nuclide calculated by pulse height discriminator 28, the count value a ₁ to a _n When the ratio exceeds the monitoring set value, an alarm signal f is output from the determination means 32 to generate an alarm.

In the radiation monitoring apparatus 10E, the γ-ray detector 27 outputs a γ-ray pulse signal q corresponding to γ-ray energy from a plurality of emission nuclides, and the pulse wave height discriminating means 28 for inputting the γ-ray pulse signal q includes an emission nuclide. counted by a pulse height discriminating γ ray pulse signal for each, the counted each nuclide, calculates the ratio of the specific counted value a ₁ to a _n to the event to be monitored, the count value a ₁ to a _n Is compared with the monitoring set value signal r by the judging means 29, and the alarm signal f can be generated when the monitoring set value is exceeded.

Also in the radiation monitoring apparatus 10E shown in the sixth embodiment, the pulse wave height discriminating means 28 can individually count γ-rays having energy levels peculiar to the event to be monitored. Since the counted ratio of events specific count value A ₁ to A _n monitored and the decision means 29 as compared to the monitoring setting value so as to generate an alarm, reliably detect the events to be monitored Moreover, it is possible to avoid erroneous detection of high-dose work during regular inspection, and it is possible to improve the operational efficiency of nuclear power plants, work efficiency such as inspection.

[Seventh Embodiment]
FIG. 7 is a system block diagram schematically showing a seventh embodiment of the radiation monitoring apparatus according to the present invention.

  In describing the radiation monitoring apparatus 10F of the seventh embodiment, the same components as those of the radiation monitoring apparatus 10C shown in the fourth embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The radiation monitoring apparatus 10F shown in FIG. 7 includes a γ-ray detection unit 21 that can detect γ-rays of emission nuclides accompanying an event to be monitored, and a γ-ray measurement signal l from the γ-ray detection unit 21. And a determination means 31 for inputting. The determination unit 31 is a first-stage determination comparator that compares the measurement value of the γ-ray measurement signal l input from the γ-ray detection unit with the monitoring set value, and the alarm signal f from the comparator is the operation to be monitored. Compared with the state signal s, a second-stage determination comparator is provided that stops the output of the alarm signal f in accordance with the operation state signal s.

  The radiation monitoring device 10F has a function of automatically invalidating the alarm output f from the determination unit 31 according to the operation state of the monitoring target device or device, with the device or device as a target to be monitored.

  The determination means 31 includes a two-stage determination comparator, and the first-stage determination comparator compares the γ-ray measurement signal l input from the γ-ray detection means 21 with the monitoring set value signal t to measure γ-rays. When the value exceeds the monitoring set value, an alarm signal f is output from the judging means 31. The output of the alarm signal f is input from the monitoring target from the operation state signal s or the plant operation mode signal of the nuclear power plant. Then, it is automatically stopped, and the alarm output is automatically disabled according to the operation state of the monitored device or apparatus.

  The radiation monitoring apparatus 10F determines whether monitoring is valid or invalid according to the operation state of the device or apparatus that is the monitoring target, and an operation state signal is input from the monitoring target according to the operation state of the monitoring target device or apparatus. Then, the alarm output from the determination means 31 is automatically invalidated.

  The radiation monitoring apparatus 10F automatically determines validity / invalidity according to the operating state of the monitoring target, accurately detects the event to be monitored, and detects the monitoring target device or apparatus like a high-dose operation during regular inspection. At the time of stop, since the operation state s to be monitored is not input, an alarm signal f is output from the determination means to generate an alarm.

  Therefore, the radiation monitoring apparatus 10F shown in the seventh embodiment can detect an event to be monitored and can avoid erroneous detection of an event that is not to be monitored, such as operating efficiency and inspection of a nuclear power plant. Work efficiency can be improved.

[Eighth Embodiment]
FIG. 8 is a system block diagram schematically showing an eighth embodiment of the radiation monitoring apparatus according to the present invention.

  In describing the radiation monitoring apparatus 10G shown in the eighth embodiment, the same components as those in the radiation monitoring apparatus 10F shown in the seventh embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The radiation monitoring apparatus 10G shown in FIG. 8 includes a γ-ray detection unit 21 capable of detecting (measuring) γ-rays of emission nuclides accompanying an event to be monitored, and a γ-ray from the γ-ray detection unit 21. A determination unit 32 to which the measurement signal l is input and a set value selection unit 33 for inputting a desired monitoring set value signal u to the determination unit 32 are provided.

  The set value selection means 33 is input with an operation state signal s to be monitored which is a device or apparatus to be monitored or a plant operation mode signal of a nuclear power plant, and one or more preset according to the operation state signal s, For example, a plurality of monitoring set values are automatically selected.

  On the other hand, the determination unit 31 receives from the γ-ray detection unit 21 the γ-ray measurement signal l of the emission nuclide accompanying the event to be monitored, and inputs this γ-ray measurement signal l from the set value selection unit 33. The monitoring set value signal to be compared is compared with the determination means 32. When the γ-ray measurement value of the released nuclide accompanying the event to be monitored exceeds the monitoring set value, the determination unit 32 outputs an alarm signal f and issues an alarm by an alarm unit (not shown).

  The radiation monitoring apparatus 10G shown in the eighth embodiment detects γ-rays from emission nuclides associated with events to be monitored, and sends a γ-ray measurement signal l that is a measurement value to the determination means 32. The determination unit 31 compares the γ-ray measurement value with the monitoring setting value from the setting value selection unit 33, and the monitoring setting value automatically set according to the operation state of the monitoring target device or apparatus is measured by the γ-ray measurement. When the value exceeds, an alarm signal f is output and an alarm is generated.

  In the radiation monitoring apparatus 10G, the setting value selection unit 33 automatically detects the monitoring set value according to the operation state of the monitoring target device or the monitoring target device, thereby reliably detecting the monitoring target event. This makes it possible to avoid erroneous detection of events that are not monitored, and to improve the operational efficiency of nuclear power plants and the work efficiency of inspections.

[Ninth Embodiment]
FIG. 9 is a system block diagram schematically showing a ninth embodiment of the radiation monitoring apparatus according to the present invention.

  In describing the radiation monitoring apparatus 10H of the ninth embodiment, the same components as those of the radiation monitoring apparatus 10 shown in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The radiation monitoring apparatus 10H shown in FIG. 9 is a gross γ-ray that can measure the emission nuclides accompanying the events to be monitored and the γ-rays gross from the nuclides that are the source of high-dose work during regular inspection. A specific energy band from a detection unit 12, a gloss determination unit 35 to which a gross γ-ray detection signal b detected by the gross γ-ray detection unit 12 is input, and a nuclide that is a radiation source for high-dose work during regular inspection Alternatively, a specific γ-ray detection unit 11 capable of measuring only γ-rays (specific γ-rays) at an energy level and a specific γ-ray measurement signal a detected by the specific γ-ray detection unit 11 are input, and this specific γ-ray is input. It is comprised from the setting value calculation means 36 which calculates the monitoring setting value corresponding to a measured value.

  The gloss determination means 35 compares the gross γ-ray measurement signal a input from the gross γ-ray detection means 12 with the monitoring set value signal v input from the set value calculation means 36. When the gross γ-ray measurement value exceeds the monitoring set value, the gloss determination means 35 outputs an alarm signal f to generate an alarm.

  At this time, the alarm set value signal v output from the set value calculating means 36 reflects the γ-ray measurement value from the nuclide that becomes the source of the high-dose work during the regular inspection. The monitoring set value of the monitoring set value signal v is changed by the measured value of the specific γ-ray from the nuclide that becomes the source of the high-dose work during the regular inspection, and is not a constant value.

  In the radiation monitoring apparatus 10H according to the ninth embodiment, when the event to be monitored is an accident event or an abnormal event, the signal level of the gross γ-ray measurement signal b detected by the gross γ-ray detection means 12 increases.

  At this time, the γ-ray energy level or energy band emitted from each nuclide associated with the abnormal event or accident event to be monitored is detected by the specific γ-ray detection means 11 and the γ-ray and energy level of the specific energy level are detected. If they are different, γ rays are not detected, and the signal level of the specific γ ray measurement signal a does not change. For this reason, the monitoring set value of the set value calculation means 36 calculated according to the specific γ-ray measurement signal a hardly changes.

  For this reason, in the gross measurement means 35, the gross γ-ray measurement value from the gross γ-ray detection means 12 exceeds the monitoring set value from the set value calculation means 36, and an alarm signal f is output from the gloss determination means 35. Is emitted.

  On the other hand, a specific energy band or energy level γ-ray from a nuclide used as a radiation source for high radiation work during regular inspection is detected by a specific γ-ray detection means 11. When the specific γ-ray detection means 11 detects γ-rays having a specific energy level (specific γ-rays), the signal level of the specific γ-ray measurement signal a increases. In response to the increase in the signal level, the signal level of the monitoring set value signal v output from the set value calculation means 36 also increases.

  When the monitoring set value from the set value calculation means 36 increases, the signal level of the gross γ ray measurement signal b detected by the gross γ ray detection means 12 also rises, but the gross γ ray measurement value calculates the set value. Since the monitoring set value from the means 36 is not exceeded, the warning signal f is not output from the gloss determination means 35.

  Therefore, the high radiation work during the regular inspection is not erroneously determined as an abnormal event or accident event to be monitored.

  In the radiation monitoring apparatus 10H shown in the ninth embodiment, the measured value of the γ-dose gross from the emission nuclide accompanying the event to be monitored, the nuclide that is the source of the high-dose work during the regular inspection, An alarm can be generated when the monitoring set value calculated from the measured value of gamma rays at a specific energy level from the nuclide that is the source of the high-dose work during the regular inspection is exceeded.

  The radiation monitoring apparatus 10H can detect a monitored event by changing a monitoring set value according to a measurement value of specific γ-rays from a nuclide that is a source of a high-dose work during a regular inspection. It becomes possible to avoid erroneous detection of events, and to improve the operational efficiency of nuclear power plants, work efficiency such as inspection.

[Tenth embodiment]
FIG. 10 is a system block diagram schematically showing a tenth embodiment of the radiation monitoring apparatus according to the present invention.

  The radiation monitoring apparatus 10I shown in the tenth embodiment is suitable when the monitoring target is a space or a fluid. The radiation monitoring apparatus 10I includes a γ camera 40 as a γ-ray image detection unit capable of measuring a γ-ray distribution position and intensity of a monitoring target such as the monitoring target space 38.

  A γ-ray image measurement signal w from the γ camera 40 is input to the data processing means 41. The data processing means 41 processes the γ-ray image measurement signal w to construct γ-ray spatial distribution information, and outputs the γ-ray spatial distribution information signal x from the data processing means 41 to the calculation determination means 43. Is done. The gamma camera 40 and the data processing means 41 constitute a gamma ray distribution measuring device 42 that measures the gamma ray distribution position / intensity in the monitoring target space.

  The calculation determination unit 43 receives the γ-ray spatial distribution information signal w from the data processing unit 41 and calculates the time change rate of the γ-ray distribution position, the time change rate of the γ-ray distribution intensity, or the γ-ray intensity from the γ-ray spatial distribution information. The calculated value obtained by calculation is compared with the monitor set value, and when the calculated value exceeds the monitor set value, an alarm signal f is output and an alarm is generated.

  The calculation determination means 43 includes a calculation unit that calculates the time change rate of the γ-ray distribution position, the time change rate of the γ-ray distribution intensity, or the γ-ray intensity and the spatial distribution position from the γ-ray spatial distribution information, A comparison unit that compares the calculated value (calculation result) calculated by the calculation unit with the monitoring set value, and a determination unit that outputs an alarm signal when the calculated value exceeds the alarm set value.

  The radiation monitoring apparatus 10I shown in FIG. 10 constructs a gamma ray spatial distribution from the gamma camera 40 capable of measuring the gamma ray distribution position / intensity in the monitoring target space 38 and the gamma ray image measurement signal w of the gamma camera 40. The time change rate of the γ-ray distribution position, the time change rate of the γ-ray distribution intensity, or the γ-ray intensity is calculated from the data processing means 41 to be performed and the spatial distribution information of the γ-rays from the data processing means 41, Is constituted by calculation determination means 43 for outputting an alarm signal f when the monitoring set value is exceeded.

  In the radiation monitoring apparatus 10I, the calculation determination means 43 calculates the time change rate or the γ-ray intensity of the γ-ray distribution position / distribution intensity in the monitoring target space 38 from the γ-ray spatial distribution information, and the calculated value is monitored. It is compared with the monitoring set value of the setting signal y, and an alarm can be generated when the monitoring set value is exceeded.

  This radiation monitoring device 10I can also detect events to be monitored, and can avoid erroneous detection of high-dose work during regular inspections that are not monitored. The working efficiency can be improved.

[Eleventh embodiment]
FIG. 11 is a system block diagram schematically showing an eleventh embodiment of the radiation monitoring apparatus according to the present invention.

  The radiation monitoring apparatus 10J shown in the eleventh embodiment includes an underwater camera 46 in a fuel pool 45 installed in a nuclear power plant, and sends an image signal z photographed by the underwater camera 46 to an image processing means 47. The image processing means 47 detects the moving speed of the monitoring target in the monitoring target space. The image processing unit 47 may perform image processing on the camera image and detect changes in the water surface such as waves and shaking caused by bubbles in the water or the bubbles.

  The moving speed signal A of the monitoring object (member, device, apparatus) detected by the image processing means 47 is input to the first determination means 48 as the discrimination determination means, and the first determination means 48 determines the monitoring object. The moving speed is compared with the monitoring set value of the monitoring set value signal B. When the moving speed exceeds the monitoring set value, the alarm signal C is output to the second determination means 49. The first determination means 48 is supplied with a monitoring set value signal B analyzed in advance by an analysis means (not shown).

  The second determination means 49 detects the γ-rays of the released nuclides accompanying the event to be monitored by the γ-ray detection means 50 above the fuel pool 45, and this γ-ray measurement signal D is used as the second determination means. The second determination means 49 outputs a warning signal f when the γ-ray measurement signal D is compared with the alarm set value signal E, and the γ-ray measurement value exceeds the alarm set value, and an alarm is generated. It is supposed to be generated.

  Thereafter, when the second determination unit 49 receives the alarm signal C from the first determination unit 48, the second determination unit 49 can output the alarm signal f from the second determination unit 49, but the alarm output from the first determination unit 48 is not received. If not, monitoring is excluded. The second determination unit 49 enables monitoring or excludes monitoring depending on the presence or absence of the monitoring output from the first determination unit 48.

  For this reason, the monitoring set value signal B input to the first determination means 48 is previously set to a monitoring setting value that can discriminate falling objects or bubbles generated as a result of damage to the fuel due to falling objects in the water in the fuel pool 45. Is set.

  The radiation monitoring apparatus 10J includes an underwater camera 46 installed in the fuel pool 45, an image processing unit 47 that calculates a moving speed of a moving object in a monitoring target space from an image signal z of the underwater camera 46, and the image processing. The first determination means 48 that outputs an alarm signal C when the moving speed of the object obtained by the means 47 exceeds the monitoring set value, and the γ-rays of the released nuclides accompanying the event to be monitored within the monitoring area The γ-ray detection means 50 that can be measured by the γ-ray and the γ-ray measurement value signal of the γ-ray detection means 50 are compared with the monitoring set value signal, and an alarm signal f is output when the γ-ray measurement value exceeds the monitoring setting value Second determining means.

  The second determination means 49 excludes the monitoring when there is no alarm output from the first determination means 48, and validates the monitoring when there is. The monitoring set value input to the first determination means 48 is set in advance to a value capable of discriminating air bubbles generated as a result of falling objects into the water or fuel being damaged by falling objects.

  The radiation monitoring apparatus 10 </ b> J shown in the eleventh embodiment is used when the moving speed of the underwater object that is the monitoring target obtained from the camera image of the underwater camera 46 installed in the fuel pool 45 exceeds the monitoring set value. The alarm signal C is output from the first determination unit 48 to the second determination unit 49, and monitoring of the monitoring target can be validated.

  This radiation monitoring device 10J can also detect an event to be monitored, detect a fall accident from the moving speed of an underwater moving object, and enable gamma ray monitoring only when a fall accident is detected. Thus, it is possible to avoid erroneous detection of high-dose work during normal regular inspection, and it is possible to improve the operational efficiency of nuclear power plants, work efficiency such as inspection.

[Twelfth embodiment]
12 and 13 are system block diagrams schematically showing a twelfth embodiment of the radiation monitoring apparatus according to the present invention.

  The radiation monitoring apparatus 10K shown in the twelfth embodiment is intended for monitoring a gaseous radionuclide 56 released from a metal container 55 such as stainless steel.

  In this radiation monitoring apparatus 10K, radioactive nuclides 56 such as iodine (Z), krypton (Kr), and xenon (Xe) are released from the activated metal container 55, while γ rays 57 are emitted from the metal container 55. Has been released. FIG. 12 shows an example in which the gaseous radionuclide 56 and the γ-ray 57 are emitted from the metal container 55. However, the gaseous radionuclide 56 and the γ-ray 57 are emitted from separate containers. Also good.

  The radiation monitoring device 10K includes a fan drive control device 61 for driving the bubble fan 60, a radiation detector 62 installed on the downstream side of the bubble fan 60, that is, the fan drive side, and the radiation detector 62 from the radiation detector 62. The activation evaluation means 63 that measures and evaluates the intensity of γ rays emitted from cobalt and cesium, which are the main components, and the evaluation result of the activation evaluation means 63, the gamma rays emitted from the gaseous radionuclide 56 Activation scattering component evaluation means 64 for evaluating scattering components contributing to the energy band.

  Further, the radiation monitoring apparatus 10K includes a gaseous band radioactivity evaluation unit 65 that evaluates the radiation intensity in the energy band of γ-rays emitted from the gaseous radionuclide 56 from the output (γ-ray measurement signal) of the radiation detector 62. Then, the evaluation result of the gaseous band radioactivity evaluation unit 65 is corrected based on the evaluation result of the activated scattering component evaluation unit 64, and the contribution component from the true gaseous radionuclide is extracted. Means 66 and alarm generating means 67 for comparing the evaluation result with a preset monitoring set value and generating an alarm when the evaluation result value is larger than the monitor set value.

  The number of radiation detectors 62 is not necessarily one, and a plurality of radiation detectors 62 may be provided, and the gaseous radioactivity evaluation means 66 includes fan control information for controlling the bubble fan 60 by the fan drive control device 61, for example, fan rotation speed. Information is input.

  The radiation detector 62 includes a radiation measuring device such as an ionization chamber or a scintillation counter.

  The radiation monitoring apparatus 10K mainly includes a radiation detector 62 as a radiation detection means for measuring the intensity of γ rays emitted from a metal activation material 55 such as stainless steel, and the activation material measured by the radiation detector 62. The means 63, 64 for predicting the scattering contribution component to the γ-ray energy emitted from the emission nuclide 56 peculiar to the event to be monitored from the γ-ray intensity from 55, and the predicted value predicted by this prediction means On the other hand, signal processing means 65 and 66 for processing the γ-ray measurement signal measured by the radiation detector 62, and whether or not the radiation number is monitored from the calculated value obtained by signal-processing the γ-ray measurement value with respect to the predicted value. And an alarm generation means 67 as a determination means for making a determination.

  In the radiation monitoring apparatus 10, a bubble fan 60 as an air collecting unit is installed, for example, in a monitoring target area 68 on the water surface of the fuel pool, and a radiation detector 62 is provided in the air collecting unit of the air collecting unit.

  In the radiation monitoring apparatus 10K shown in the twelfth embodiment, the fan drive control device 61 drives the airflow fan 60 to bring the gaseous radionuclide 56 closer to the radiation detector 62. By driving the airflow fan 60, the contribution component due to radiation from the gaseous radionuclide 56 can be increased from the γ-ray 57.

  If the fan operation of the airflow fan 60 is variable, only the detection signal component corresponding to the amount of gas radioactivity that contributes to the radiation detector 62 varies. The detection signal component that does not vary is the γ-ray 57 from the metal container 55 that is an activation product that does not change due to the flow of the airflow.

  Therefore, by detecting the radiation with the radiation detector 62, the fluctuation component can be extracted by the gaseous radioactivity evaluation means 66, and only the radiation flow from the gaseous radionuclide 56 can be identified.

  Although the radiation monitoring apparatus 10K of the twelfth embodiment has been described by taking an example in which the gaseous radionuclide 56 emits γ rays, there are cases in which β rays are emitted. In this case, the ambient air is ionized by β-rays, and the ionized ions are detected by the radiation detector 62 such as a vented ionization chamber, whereby β-ray radiation can be detected.

  On the other hand, the radiation detector 62 detects γ-rays emitted from the container 55 which is an activated metal radioactive material, and the γ-ray intensity corresponding to the detected γ-ray energy is the activation evaluation means. 63 is extracted. When, for example, stainless steel in the metal container 55 is activated, cobalt (Co) 60 and cesium (Cs) 137 are mainly generated.

  Cobalt 60 emits gamma rays with energy levels of 1.17 Mev and 1.33 Mev, and cesium 137 emits gamma rays with an energy level of 662 keV.

  FIG. 13 shows a measurement example of the energy spectrum of γ rays. For example, in the case of cesium (Cs) 137, the G portion corresponds to an energy band near 662 keV, and the γ-ray intensity of Cs 137 can be measured by observing a photoelectric peak observed near that energy.

  In the actual measurement, as shown by the dotted line H in the energy region lower than the γ-ray energy region G of Cs137, a till due to Compton scattering is generated. The shape of the till G can be predicted by the detection characteristics of the radiation detector 62 when the size of the photoelectric peak is determined.

  Utilizing the characteristics of the radiation detector 62, the γ-ray energy is obtained by the activated scattered component evaluation means 64 as means for predicting the scattering component contribution component to the γ-ray energy emitted from the emission nuclide specific to the event to be monitored. Is determined.

  On the other hand, when iodine (I) 133 is considered as the gaseous radionuclide 56, the energy level of the emitted γ-ray is 87% of 530 keV, and a photoelectric peak is generated in the J region of energy lower than the photoelectric peak G of Cs137.

  The radiation energy in the energy region J detected by the radiation detector 62 is the sum of the photoelectric peak of γ rays from iodine (I) 133 and the till portion H by Compton scattering of Cs137.

  The gamma ray signal of energy corresponding to iodine (I) 133 is performed by the gaseous band radioactivity evaluation means 65 that measures the energy portion J from the radiation detector 62.

  Further, the Compton scattering component of Cs137 is removed by the gaseous radioactivity evaluation means 66, and the true radiation intensity of iodine (I) 133 is calculated by the gaseous activation evaluation means 66.

  The gaseous radionuclide 56 includes krypton (Kr) and xenon (Xe) in addition to Cs133. The energy of the emitted γ-rays of Kr and Xe is lower than that of Cs133 (662 keV). For this reason, the contribution of the gaseous radionuclide can be clarified by providing a function for correcting Comps scattering of Cs, Kr, and Xe.

  Then, the radiation intensity of iodine (I) 133 is compared with a plurality of comparison values (known) set for each rare gas of the gaseous radionuclide 56 by the alarm generation means 67, and the radiation intensity of iodine is compared with the comparison value. When it is large, an appropriate alarm is generated according to the value.

  This radiation monitoring apparatus 10K reduces the influence of γ rays due to activation of the metal container 55 which is a radioactive substance, improves the radiation detection sensitivity for the gaseous radionuclide 56 to be monitored, and from the gaseous radionuclide 56 The radiation intensity can be measured accurately and accurately.

The block diagram which shows 1st Embodiment of the radiation monitoring apparatus of this invention. The block diagram which shows 2nd Embodiment of the radiation monitoring apparatus of this invention. The block diagram which shows 3rd Embodiment of the radiation monitoring apparatus of this invention. The block diagram which shows 4th Embodiment of the radiation monitoring apparatus of this invention. The block diagram which shows 5th Embodiment of the radiation monitoring apparatus of this invention. The block diagram which shows 6th Embodiment of the radiation monitoring apparatus of this invention. The block diagram which shows 7th Embodiment of the radiation monitoring apparatus of this invention. The block diagram which shows 8th Embodiment of the radiation monitoring apparatus of this invention. The block diagram which shows 9th Embodiment of the radiation monitoring apparatus of this invention. The block diagram which shows 10th Embodiment of the radiation monitoring apparatus of this invention. The block diagram which shows 11th Embodiment of the radiation monitoring apparatus of this invention. The block diagram which shows 12th Embodiment of the radiation monitoring apparatus of this invention. The figure which shows the example of a measurement of the energy spectrum of a gamma ray.

Explanation of symbols

10, 10A to 10K Radiation monitoring device 11 Specific γ-ray detection means 12 Gross γ-ray detection means 13 Specific determination means 14 Gross determination means 15 and 17 Determination device 16 Alarm generation means 18 Calculation means 19 Determination means 21 γ-ray detection means 22 Calculation Means (Gamma ray time rate of change calculation means)
23 determination means 25 calculation means (first-order lag calculation means for γ rays)
26 Determination means 27 γ-ray detector 28 Pulse height discrimination means 29, 31, 32 Determination means 33 Set value selection means 35 Gross determination means 36 Set value calculation means 38 Monitoring target space 40 γ camera (γ-ray image detection means)
41 data processing means 43 calculation judgment means 45 fuel pool 46 underwater camera 47 image processing means 48 first judgment means 49 second judgment means 50 gamma ray detection means 55 metal container 56 gaseous radionuclide 57 gamma ray 60 bubble fan 61 fan Drive controller 62 Radiation detector 63 Activation evaluation means 64 Activation scattering component evaluation means 65 Gaseous band radioactivity evaluation means 66 Gaseous activity evaluation means 67 Alarm generation means

Claims (16)

Specific γ-ray detection means for detecting only γ-rays from nuclides that are sources of high-dose work;
Gross gamma ray detection means for detecting the emission nuclide associated with the event to be monitored and the gamma dose gross from the nuclide that is the source of high-dose work,
A determination device that excludes radiation monitoring by the gross γ-ray measurement value from the gross γ-ray detection means by the γ-ray measurement value from the specific γ-ray detection means;
A radiation monitoring apparatus, wherein an event to be monitored is detected by the determination apparatus. Specific γ-ray detection means for detecting only γ-rays from nuclides that are sources of high-dose work;
Gross gamma ray detection means for detecting the emission nuclide associated with the event to be monitored and the gamma dose gross from the nuclide that is the source of high-dose work,
A determination device that inputs γ-ray measurement signals from both γ-ray detection means and simultaneously monitors both γ-ray measurement values;
A radiation monitoring apparatus, wherein an event to be monitored is detected by the determination apparatus. Specific γ-ray detection means for detecting only γ-rays from nuclides that are sources of high-dose work;
A gross γ-ray detection means for detecting the detected nuclides associated with the events to be monitored and the γ-ray gross from the nuclides that are the source of high-dose work;
A difference value calculation means for calculating a difference value between the γ-ray measurement values respectively measured by the both γ-ray detection means;
Determination means for determining radiation monitoring from the magnitude of the difference value from the calculation means,
A radiation monitoring apparatus, wherein an event to be monitored is detected by the determination means. Γ-ray detection means for detecting γ-rays from emission nuclides associated with events to be monitored;
A calculation means for calculating a time change rate of the γ-ray measurement value measured by the γ-ray detection means;
Determination means for determining radiation monitoring from the magnitude of the time rate of change of the γ-ray measurement value output from the calculation means,
A radiation monitoring apparatus, wherein an event to be monitored is detected by the determination means. Γ-ray detection means for detecting γ-rays from emission nuclides associated with events to be monitored;
A calculation means for performing a first-order lag process for multiplying the γ-ray measurement value measured by the γ-ray detection means by N and limiting the radiation dose to the environment to a specified value or less;
Determination means for determining radiation monitoring from the calculated value subjected to the first-order lag processing output from the calculation means,
A radiation monitoring apparatus, wherein an event to be monitored is detected by the determination means. Γ-ray detection means for detecting γ-rays from a plurality of emission nuclides accompanying an event to be monitored;
Pulse wave height discriminating means for counting γ rays of energy levels for each emission nuclide by pulse height discrimination based on the γ ray measurement value from the γ ray detecting means,
Determination means for discriminating radiation monitoring from a ratio of count values for each emission nuclide counted by the pulse wave discrimination means,
A radiation monitoring apparatus, wherein an event to be monitored is detected by the determination means. Γ-ray detection means for detecting γ-rays from emission nuclides associated with events to be monitored;
Determination means for determining radiation monitoring from the magnitude of the γ-ray measurement value measured by the γ-ray detection means,
The determination means is configured to be able to input an operation mode signal from a plant or an operation status signal from a monitoring target device or apparatus, and is set to automatically switch between valid / exclude radiation monitoring according to the input signal,
A radiation monitoring apparatus, wherein an event to be monitored is detected by the determination means. Γ-ray detection means for detecting γ-rays from emission nuclides associated with events to be monitored;
A set value selection means for automatically switching the monitor set value according to the operation mode signal from the plant or the operation status signal from the monitored device or apparatus;
A determination unit that determines radiation monitoring by comparing the γ-ray measurement value from the γ-ray detection unit with the monitoring setting value from the setting value selection unit;
A radiation monitoring apparatus, wherein an event to be monitored is detected by the determination means. Specific γ-ray detection means for detecting only specific γ-rays from nuclides that are sources of high-dose work;
Gross gamma ray detection means for detecting the emission nuclide associated with the event to be monitored and the gamma dose gross from the nuclide that is the source of high-dose work,
A set value calculating means for calculating a monitoring set value from the γ-ray measured value measured by the specific γ-ray detecting means;
A determination means for determining the radiation monitoring by comparing the gross γ-ray measurement value from the gross γ-ray detection means with the monitoring set value from the setting value calculation means,
A radiation monitoring apparatus, wherein an event to be monitored is detected by the determination means. A gamma ray distribution measurement device for measuring the gamma ray distribution position and intensity in the monitored space; and
Calculating the time change rate of the γ-ray distribution position or γ-ray distribution intensity from the γ-ray spatial distribution information obtained from this γ-ray distribution measuring device, and having a calculation determination means for determining radiation monitoring,
A radiation monitoring apparatus, wherein an event to be monitored is detected by the calculation determination means. The calculation determination means inputs γ-ray spatial distribution information from the γ-ray distribution measuring apparatus, calculates a time change rate of γ-ray intensity at a specific location in the monitoring target space, and determines radiation monitoring from the time change rate. The radiation monitoring apparatus according to claim 10, which is configured as described above. The calculation determination means inputs γ-ray spatial distribution information from the γ-ray distribution measuring device, calculates the width of the γ-ray distribution position in the monitoring space, and determines radiation monitoring from the width of the γ-ray distribution position. The radiation monitoring apparatus according to claim 10, which is configured as described above. Γ-ray detection means for detecting γ-rays from emission nuclides in the monitored area around the fuel pool;
An underwater camera provided in the fuel pool;
Image processing means for image processing the camera image from the underwater camera and calculating the moving speed of the monitoring object;
Discrimination discrimination means for discriminating underwater work and drop accidents during normal regular inspection from the moving speed of the monitored object processed by the image processing means;
A judgment means for judging the effectiveness and invalidity of radiation monitoring of the monitored area by the discrimination output from the discrimination judgment means,
A radiation monitoring apparatus, wherein an event to be monitored is detected by the determination means. The image processing means performs image processing on the camera image, detects bubbles in the water or changes in the water surface due to the bubbles,
The radiation monitoring apparatus according to claim 13, wherein the radiation monitoring apparatus is set so as to discriminate an underwater operation and a drop accident during normal regular inspection from the change in the underwater bubbles and the water surface by the discrimination judgment means. Radiation detecting means for detecting the intensity of γ-rays emitted from the metal radioactive material,
Means for predicting the scattering contribution component to the γ-ray energy emitted from the emission nuclide peculiar to the event to be monitored from the γ-ray intensity of the radioactive material measured by the radiation detector;
With respect to the predicted value predicted by the prediction means, the gamma ray measurement signal from the radiation detector is monitored, and the determination means for determining the radiation monitoring is included.
A radiation monitoring apparatus, wherein an event to be monitored is detected by the determination means. The radiation monitoring apparatus according to claim 15, further comprising: a collecting unit that collects air in the monitoring target area; and a radiation detector provided in an air collecting unit of the collecting unit.

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