Personal dosimeter

The present invention relates to a personal dosimeter carried by a worker in order to measure the exposure dose of a worker in a facility handling radioactive substances.

Facilities that handle radioactive materials, such as nuclear power plants, have a "radiation control area", and when entering that area, carry a personal dosimeter and the amount of radiation exposed to the workers (hereinafter referred to as the radiation dose). (Called) is managed for each individual. To operate the personal dosimeter, let the worker carry the personal dosimeter with a string or clip, read the exposure dose data from the personal dosimeter with a dedicated reader at the time of entry and exit, and manage the entry / exit time and exposure dose. To do.

In addition, radiation controlled areas are classified into A / B / C areas according to the degree of contamination, and especially when entering area C (a contaminated area within the controlled area), an entry dedicated to area C called a changing place. A place to leave is provided, and clothes for area B (hereinafter referred to as B clothes) are changed to clothes for area C (hereinafter referred to as C clothes) to enter the area.

However, when changing from B clothes to C clothes in order to enter the C area, the personal dosimeter may be temporarily separated from the body and kept nearby. In this case, forget to carry the personal dosimeter. There is a possibility that you will enter Area C as it is.

Therefore, conventionally, the technique described in Patent Document 1 has been proposed. Patent Document 1 describes an individual dose that detects a worker's body temperature, heart sound, heart rate, amount of light in a pocket, etc., and if the detected value is less than the set value, determines that the worker is not carrying and generates an alarm. The total is described.

<p><patcit num="1"><text>Japanese Unexamined Patent Publication No. 2001-208847</text></patcit></p>

<p> However, in the technique described in Patent Document 1, in order to detect the body temperature, heart sound, and heart rate of the worker, it is necessary to bring the personal dosimeter into close contact with the worker, and it is very troublesome to put in and take out the personal dosimeter. Therefore, it becomes difficult to carry. Moreover, when the personal dosimeter is separated from the worker, it becomes difficult to detect the body temperature, heart sound, and heart rate of the worker, and an alarm may be generated during the work.</p><p> In addition, when detecting the amount of light in the pocket and determining whether or not a personal dosimeter is carried, for example, when a worker changes clothes from B clothes to C clothes, the personal dosimeter is temporarily placed on the table. If the personal dosimeter is placed with the light amount sensor facing the table, the light amount sensor will not be able to detect the light. As a result, it may be determined that the personal dosimeter is carried and the alarm may not be generated.</p><p> An object of the present invention is to provide a personal dosimeter capable of solving such a problem and surely preventing a worker from not carrying the personal dosimeter.</p>

<p> In order to achieve the above object, the present invention includes the following configurations.</p><p> (1) A motion sensor for detecting the movement of the housing and an alarm means for generating an alarm in a personal dosimeter to be carried by a worker of a facility handling radioactive substances by providing a measuring means for measuring the exposure dose in the housing. The motion determination means that monitors the detection result of the motion sensor and determines whether or not the detection result has changed to a predetermined value or more, and the motion determination means sets a predetermined value based on the detection result of the motion determination means. The timer control means for starting the timer means for measuring the time in the state where it is determined that the change has not occurred, and the alarm means for generating an alarm when the time value of the timer means exceeds a predetermined time. A personal dosimeter characterized by being equipped with an alarm control means for controlling.</p><p> According to (1), when the motion sensor detects the movement of the housing, it is assumed that the personal dosimeter is carried by the worker, the alarm is not generated, and the motion sensor moves the housing. If it is not detected for a predetermined time, it is assumed that the personal dosimeter is not carried by the worker, and an alarm is generated by the alarm means. As a result, it becomes possible to make the worker aware of the existence of the personal dosimeter, and it is possible to prevent the worker from not carrying the personal dosimeter.</p><p> (2) In (1), there is a posture determining means for determining whether or not the posture of the housing is a posture that cannot be placed based on the detection result of the motion sensor, and the alarm control means. Is characterized in that, when the posture determining means determines that the posture cannot be placed, the alarm means is controlled so as not to generate an alarm regardless of the time value of the timer means. Total.</p><p> According to (2), the posture of the housing is obtained based on the detection result of the motion sensor, and the posture of the housing is, for example, when the personal dosimeter is placed on a nearby table when changing clothes. It is determined whether or not the posture at that time is a posture that can be placed on the table. Then, when the posture determining means determines that the posture can be placed, an alarm can be generated, and when the posture determining means determines that the posture cannot be placed, the alarm is not generated. .. As a result, when it is necessary to generate an alarm, the alarm can be generated.</p><p> (3) In (1) or (2), the charging battery for supplying power and the charging determining means for determining whether or not the charging battery is being charged are provided, and the alarm control means is said to charge. A personal dosimeter characterized in that when it is determined that the determination means is charging, the alarm means is controlled so as not to generate an alarm regardless of the time value of the timer means.</p><p> According to (3), the alarm control means does not generate an alarm at the time of charging even if the personal dosimeter is not carried by the worker. As a result, it is possible to prevent the alarm from being generated when the alarm is not required.</p><p> (4) In (1) to (3), the alarm control means stops the alarm when the detection result of the motion sensor changes to a predetermined value or more while the alarm is generated. Total.</p><p> According to (4), for example, when an alarm is generated during changing clothes, it can be easily stopped.</p><p> (5) In (1) to (4), the predetermined time is based on the time measurement value of the timer means at the time when the detection result of the motion sensor changes to a predetermined value or more after the timer means starts timing. A personal dosimeter characterized by having a means of change to change.</p><p> According to (5), for example, when changing clothes, the predetermined time is changed based on the time from temporarily placing the personal dosimeter on the table to carrying it again. This makes it possible to generate an alarm according to the time when the worker changes clothes.</p>

<p> According to the present invention, it becomes possible to provide a personal dosimeter capable of more reliably reducing non-carrying of a personal dosimeter.</p>

<figref num="1">It is a perspective view which shows the appearance of the personal dosimeter in one Embodiment of this invention.</figref><figref num="2">It is a block diagram which shows the electrical structure of the personal dosimeter in one Embodiment of this invention.</figref><figref num="3">It is a perspective view which shows the appearance of a reader.</figref><figref num="4">It is a perspective view which shows the appearance of a storage rack.</figref><figref num="5">It is a flowchart which shows the alarm generation processing which is executed in one Embodiment of this invention.</figref><figref num="6">It is a flowchart which shows another example of the alarm generation processing executed in one Embodiment of this invention.</figref>

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the appearance of a personal dosimeter according to an embodiment of the present invention. The personal dosimeter 1 includes a housing 10, a liquid crystal display panel 12, a non-carrying warning lamp 14, an interface 16, a charging terminal 18, and the like.

The housing 10 is a rectangular parallelepiped case body, and a liquid crystal display panel 12 is provided on the front surface of the housing 10. In addition, non-carrying warning lamps 14 are provided on the front and rear surfaces of the housing 10. Further, an interface 16 is provided on the upper surface of the housing 10, and a charging terminal 18 is provided on the lower surface of the housing 10. Inside the housing 10, a circuit board on which a CPU 20 and a memory 22 (see FIG. 2) are mounted, a radiation sensor 24 (see FIG. 2), a motion sensor 26 (see FIG. 2), and a speaker 28 (see FIG. 2). ) And a rechargeable battery 30 (see Fig. 2).

The liquid crystal display panel 12 displays the radiation dose of the worker.

The non-carrying warning lamp 14, which will be described in detail later, emits light when the motion sensor 26 (see FIG. 2) does not detect the movement of the housing 10 for a predetermined time, that is, when it is determined that the housing 10 is not carried. is there.

The interface 16 is connected to the reader 50 (see FIG. 3) and enables data transmission / reception between the personal dosimeter 1 and the reader 50 (see FIG. 3).

The charging terminal 18 is connected to the charging terminal 18 and the storage rack 60 when the personal dosimeter 1 is inserted into the storage rack 60 (see FIG. 4) in order to charge the rechargeable battery 30 (see FIG. 2) of the personal dosimeter 1. Is to connect.

FIG. 2 is a block diagram showing an electrical configuration of a personal dosimeter according to an embodiment of the present invention.

The CPU 20 controls the entire personal dosimeter 1. A liquid crystal display panel 12, a non-carrying warning lamp 14, an interface 16, a memory 22, a radiation sensor 24, a motion sensor 26, and a speaker 28 are connected to the CPU 20.

The memory 22 stores various programs for operating the personal dosimeter 1 and data on the radiation dose of the worker. Further, the CPU 20 updates the count value stored in the predetermined storage area of the memory 22 to a value that is counted up by a fixed value at regular time intervals, so that the predetermined storage area of the memory 22 becomes a timer means. Functions as the corresponding timer 23.

The radiation sensor 24 detects the radiation amount and transmits the detection result to the CPU 20. Then, the CPU 20 calculates the exposure dose of the worker up to the present time and stores it in the memory 22, and also controls to display the exposure dose of the worker on the liquid crystal display panel 12.

The motion sensor 26 includes a gyro sensor that detects the angle and angular velocity of an object and an acceleration sensor that detects acceleration, and detects the three-dimensional movement and inclination of the personal dosimeter 1. The detection result of the motion sensor 26 is transmitted to the CPU 20. By setting the sensitivity to the maximum, the motion sensor 26 can detect even a minute movement.

Although the details will be described later, the speaker 28 outputs voice when the motion sensor 26 (see FIG. 2) does not detect the movement of the housing 10 for a predetermined time, that is, when it is determined that the speaker 28 is not portable. Further, even when the radiation sensor 24 detects an exposure dose of a predetermined value or more, the CPU 20 outputs a voice to give a warning. Here, the sound output when it is determined that the personal dosimeter 1 is not carried and the sound output when the radiation sensor 24 detects an exposure dose of a predetermined value or more are different tones. The rechargeable battery 30 serves as a power source for the personal dosimeter 1.

The CPU 20 functions as an operation determination means, a timer control means, a posture determination means, a charge determination means, and an alarm control means.

The motion determination means (CPU 20) determines whether or not the acceleration detected by the motion sensor 26 has changed by a predetermined value or more, and when the acceleration changes by a predetermined value or more, the housing 10 moves. If it is determined that the housing 10 is used and the acceleration is maintained within a predetermined value, it is determined that the housing 10 is not moving.

The timer control means (CPU 20) starts and stops the timer 23 based on the detection result of the motion sensor 26.

In the posture determination means (CPU 20), the motion sensor 26 obtains the current posture of the housing 10 based on the direction and angle of inclination, and determines whether or not the posture of the housing 10 is a specific posture. Is.

The charge determination means (CPU 20) determines whether or not the personal dosimeter 1 is set in the storage rack 60 (see FIG. 3). When the personal dosimeter 1 is set in the storage rack 60 (see FIG. 4), the personal dosimeter 1 is stored in the storage rack 60 (see FIG. 4) and the rechargeable battery 30 is in the charged state. It becomes.

The alarm control means (CPU 20) controls the non-carrying warning lamp 14 to emit light and the alarm sound to be output from the speaker 28 when the time value of the timer 23 exceeds a predetermined time.

FIG. 3 is a perspective view showing the appearance of the reader. The reader 50 reads the exposure dose data measured by the personal dosimeter 1 from the memory 22 and manages the exposure of each worker individually. The reader 50 is provided with a slot 52 into which the personal dosimeter 1 is inserted, and a card reader 54 for reading worker information from the worker's ID card. At the back of the slot 52, a signal input / output terminal (not shown) connected to the signal input / output terminal of the interface 16 of the personal dosimeter 1 is provided, and by inserting the personal dosimeter 1 into the slot 52, the personal dosimeter 1 is inserted. The signal input / output terminals are connected to each other so that the personal dosimeter 1 and the reader 50 can transmit and receive.

Further, an IC chip is embedded in the ID card, and by holding the ID card over the card reading device 54, worker information is read from the IC chip to the card reading device 54.

FIG. 4 is a perspective view showing the appearance of the storage rack. The storage rack 60 stores a plurality of personal dosimeters 1. When a worker enters the radiation controlled area, the personal dosimeter 1 is taken out from the storage rack 60, and the worker removes the personal dosimeter 1 from the radiation controlled area. When leaving the area, insert the personal dosimeter 1 into the storage rack 60.

A plurality of slots 62 are formed in the storage rack 60, and a charging terminal (not shown) that electrically connects to the charging terminal 18 of the personal dosimeter 1 is provided in the back of the slot 62. There is. Further, the charging terminal (not shown) is connected to a power source for charging. Therefore, by inserting the personal dosimeter 1 into the storage rack 60, the rechargeable battery 30 (see FIG. 2) is in a charged state.

When a worker enters the radiation controlled area, the worker first removes the personal dosimeter 1 from the storage rack 60, and then performs the entry procedure by the reader 50. Specifically, the worker inserts the personal dosimeter 1 into the slot 52 of the reader 50 and holds the ID card over the card reader 54. In addition, operate the numeric keypad to enter the reason for entering the area. As a result, the ID card number and the personal dosimeter 1 are associated with each other, and the entry procedure is completed. After completing the entry procedure, remove the personal dosimeter 1 from slot 52 and enter the radiation controlled area. Workers carry a personal dosimeter 1 at all times while in the radiation controlled area.

Similarly, when the worker leaves the radiation controlled area, the personal dosimeter 1 is inserted into the slot 52 of the reader 50. Further, the ID card is held over the card reader 54. As a result, the exit procedure is carried out, and the reader 50 reads the data of the reviewer dose measured by the personal dosimeter 1 from the memory 22 and confirms whether or not the radiation is exposed to the specified value or more.

When leaving the area, the personal dosimeter 1 is pulled out from the slot 52 and the personal dosimeter 1 is inserted into the storage rack 60 to store the personal dosimeter 1 in the storage rack 60. Then, the same procedure will be performed the next time you enter or leave the radiation controlled area.

Next, the alarm generation process executed by the CPU 20 of the personal dosimeter 1 will be described with reference to FIG. The CPU 20 monitors the detection result of the motion sensor 26, and determines whether or not the acceleration detected by the motion sensor 26 has changed to a predetermined value or more within a certain period of time (for example, 10 seconds). Then, the CPU 20 executes the alarm generation process shown in FIG. 5 when the acceleration does not change to a predetermined value or more for a certain period of time (for example, 10 seconds).

First, in step S10, the CPU 20 activates the timer 23 and measures the time for determining that the housing 10 is not moving. When this process is completed, the process is moved to step S12.

In step S12, the CPU 20 performs a process of determining whether or not the housing 10 has moved based on the detection result of the motion sensor 26. If it is determined that the housing 10 has moved, the process is moved to step S26. If it is not determined that the housing 10 has moved, the process is moved to step S14.

In step S14, the CPU 20 performs a process of determining whether or not the personal dosimeter 1 is stored in the storage rack 60, that is, in the charged state. Specifically, it is determined whether or not the charging terminal 18 of the personal dosimeter 1, the storage rack 60, and the charging terminal (not shown) are electrically connected. If it is determined that the personal dosimeter 1 is stored in the storage rack 60, the process is moved to step S26. If it is not determined that the personal dosimeter 1 is stored in the storage rack 60, the process is moved to step S16.

In step S16, the CPU 20 performs a process of determining whether or not the personal dosimeter 1 is in the state of being set in the reader 50. If it is determined that the personal dosimeter 1 is in the state of being set in the reader 50, the process is moved to step S26. If it is not determined that the personal dosimeter 1 is in the state of being set in the reader 50, the process is moved to step S18.

In step S18, the CPU 20 performs a process of identifying the current posture of the personal dosimeter 1 based on the detection result of the motion sensor 26. When this process is completed, the process is moved to step S20.

In step S20, whether the posture identified in the process of step S18 is a specific posture, for example, the surface of the personal dosimeter 1 having the liquid crystal display panel 12 is either vertically upward or vertically downward. Performs the process of determining whether or not. The specific posture is not limited to the one described above. For example, a posture in which the personal dosimeter 1 can be placed on a flat surface may be set as a specific posture, and may be appropriately set according to the shape of the personal dosimeter 1. It is possible. If it is determined that the personal dosimeter 1 is in a specific posture, the process is moved to step S22. If it is not determined that the personal dosimeter 1 is in a specific posture, the process is moved to step S26.

In step S22, the CPU 20 performs a process of determining whether or not the value of the timer 23 started in step S10 exceeds a predetermined time. If it is determined that the value of the timer 23 exceeds the predetermined time, the process is moved to step S24. If it is not determined that the value of the timer 23 exceeds the predetermined time, the process is moved to step S12.

In step S24, the CPU 20 performs a process of causing the non-carrying warning lamp 14 to emit light and outputting an alarm sound from the speaker 28. For example, after the value of the timer 23 exceeds a predetermined time, an alarm (light emission of the non-carrying warning lamp 14 and voice output of the speaker 28) is generated for 10 seconds. As for the alarm sound, the volume is turned down at first and then gradually turned up. The alarm activation time does not have to be 10 seconds and can be set as appropriate. When this process is completed, the process is moved to step S12. That is, when the state in which the motion sensor 26 does not detect the operation elapses for a predetermined time, the CPU 20 determines that the personal dosimeter 1 is not carried by the worker, and executes a control to generate an alarm.

In step S26, the CPU 20 performs a process of stopping the timer 23 started in step S10. When this process is completed, the process is moved to step S28.

In step S28, the CPU 20 performs a process of resetting (setting to 0) the clock value of the timer 23. When this process is completed, the alarm generation process is terminated and the state shifts to the monitoring state of the detection result of the motion sensor 26.

By the way, in the present embodiment, the motion sensor 26 of the personal dosimeter 1 is set to have high sensitivity, so that even a slight movement of the worker can be detected. Therefore, when the worker carries the personal dosimeter 1, the alarm generation process shown in FIG. 5 is not executed.

However, in the radiation controlled area, it is necessary to change from B clothes to C clothes in order to enter the area from B area to C area. At the time of this change of clothes, the personal dosimeter 1 may be temporarily separated from the body and placed near the body, and in this case, the alarm generation process shown in FIG. 5 may be executed. Therefore, as the predetermined time used in the process of step S22 shown in FIG. 5, it is preferable to set the average value of the time required for changing clothes from B clothes to C clothes, for example, the changing time of a plurality of workers.

According to the present embodiment configured as described above, when the motion sensor 26 detects the movement of the housing 10, the personal dosimeter 1 is carried by the worker, and the motion sensor 26 If the movement of the housing 10 is not detected for a predetermined time, it is determined that the personal dosimeter 1 is not carried by the worker, and if it is not carried, the non-carrying warning lamp 14 emits light and the sensor 28. Generates an alarm such as the ringing of. As a result, it becomes possible to make the worker aware of the existence of the personal dosimeter 1, and it is possible to prevent the personal dosimeter 1 from being uncarried.

Further, according to the present embodiment, the posture determination means (CPU 20) obtains the posture of the housing 10 based on the detection result of the motion sensor 26, and the posture of the housing 10 is, for example, the personal dosimeter 1 on the locker. It is determined whether or not the posture can be placed. An alarm is not generated when it is determined that the posture cannot be placed, and an alarm can be generated when the posture can be placed. As a result, when it is necessary to generate an alarm, the alarm can be generated.

Further, according to the present embodiment, when there is no need for an alarm even if the personal dosimeter 1 is not carried by the worker, for example, the personal dosimeter 1 is set in the storage rack 60 and the rechargeable battery 30 is charged. When the personal dosimeter 1 is stored, or when the personal dosimeter 1 is set in the reader 50 and the reader 50 is reading data from the personal dosimeter 1, the alarm control means (CPU 20) is used. Prevent the alarm from being generated. As a result, it is possible to prevent the alarm from being generated when the alarm is not required.

Further, according to the present embodiment, the alarm control means (CPU20) stops the alarm when the detection result of the motion sensor changes to a predetermined value or more during the alarm generation, so that the worker can use the personal dosimeter 1 By carrying the, the alarm will be stopped, and the operation to stop the alarm will not be necessary.

Further, according to the present embodiment, when the personal dosimeter 1 is not sufficiently inserted into the slot 62 of the storage rack 60, the charging terminal 18 and the charging terminal (not shown) of the storage rack 60 are not connected. Therefore, the personal dosimeter 1 is in a state where an alarm can be generated (NO in S14 in Fig. 5). However, as shown in FIG. 4, the posture of the personal dosimeter 1 inserted into the slot 62 of the storage rack 60 is such that the surface on which the liquid crystal display panel 12 is formed faces the horizontal direction. As a result, since the personal dosimeter 1 is not in a specific posture, the personal dosimeter 1 does not generate an alarm (NO in S20 in FIG. 5). Therefore, even if the worker does not sufficiently insert the personal dosimeter 1 into the slot 62 of the storage rack 60, the personal dosimeter 1 will not generate an alarm, and the alarm does not need to be generated. It is possible to prevent the occurrence of an alarm.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, in the above-described embodiment, the predetermined time used in the process of step S22 shown in FIG. 5 is a constant value. In this case, the worker who changes clothes quickly may not notice the non-carrying of the personal dosimeter 1 because the alarm generation timing is delayed. In addition, for workers who change their clothes late, even if an alarm occurs, the operation of holding the personal dosimeter 1 in their hands and stopping the alarm is repeated, and as a result, the awareness of the alarm may be diminished. Therefore, it may be possible to change it as appropriate according to the changing time of the worker.

FIG. 6 is a flowchart showing another example of the alarm generation process executed in the embodiment of the present invention. Note that the same processing as the processing in the alarm generation processing shown in FIG. 5 is assigned the same step number, and detailed description thereof will be omitted.

The alarm generation process shown in FIG. 6 is obtained by adding the process of step S27 to the alarm generation process shown in FIG. That is, in the process of step S12, a process of determining whether or not the housing 10 has moved is performed based on the detection result of the motion sensor 26, and if it is determined that the housing 10 has moved, the process is performed in step S27. Move. If it is not determined that the housing 10 has moved, the process is moved to step S14. The processing after step S14 is the same as the alarm generation processing shown in FIG.

In step S27, the CPU 20 performs a process of changing a predetermined time. For example, the CPU 20 changes the predetermined time to a time one minute earlier when the time value of the timer 23 is one minute or more earlier than the predetermined time, and when the time value of the timer 23 is one minute or more later than the predetermined time. Performs a process of changing the predetermined time to a time one minute later, and does not change the predetermined time if the time value of the timer 23 is within one minute before and after the predetermined time. When this process is completed, the process is moved to step S26. In this way, the CPU 20 corresponds to the changing means for changing the predetermined time. The processing after step S26 is the same as the alarm generation processing shown in FIG.

By performing such an alarm generation process, as the predetermined time used in the process of step S22, the personal dosimeter 1 is placed on, for example, a locker last time, the clothes are changed, and the personal dosimeter 1 is carried again. Based on the time until, the predetermined time that will be the standard for the next alarm is changed. As a result, the worker can carry the same personal dosimeter 1 each time to generate an alarm when the worker's change of clothes is completed, and the worker is more likely to not carry the personal dosimeter 1. It will be possible to warn with certainty.

Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-described embodiments. For example, according to the above-described embodiment, when changing clothes when entering the area from area B to area C in the radiation controlled area, a warning is given that the personal dosimeter 1 is not carried, but the present invention is not limited to this. In addition to changing clothes, it is possible to warn of non-carrying of personal dosimeter 1 in all cases where personal dosimeter 1 may not be carried in the radiation controlled area.

1 Personal dosimeter 10 chassis 12 LCD panel 14 Non-carrying warning lamp 16 interface 18 Charging terminal 20 CPU 22 memory 23 Timer 24 Radiation sensor 26 motion sensor 28 speakers 30 rechargeable battery 50 reader 52, 62 slots 54 Card reader 60 storage rack