JP2015175731A - Radiation measurement device and radiation measurement method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and accurately measure the radiation dose of the bottom material of a water area.SOLUTION: A radiation measurement device 2 comprises a gamma-ray measurement sensor 4, a measurement data collection terminal unit 5A which controls measurement of the sensor 4 and records measurement data, a control terminal unit 5B which is operated by an operator M and controls the gamma-ray measurement sensor 4 through the measurement data collection terminal unit 5A, and a waterproof container 3 which stores machines 4, 5A and is put into the water. The waterproof container 3 is attached with a spindle 20 and a string 15 having a float 14 on the tip. The gamma-ray measurement sensor 4 secures an air space S with the inner surface of the waterproof container 3. In a first step S1, the waterproof container 3 is carried to the measurement spot of a water area W by a vessel. In a second step S2, after starting the measurement by the control terminal unit 5B, the waterproof container 3 is put into the water, and data is stored after measurement time elapses. In a third step S3, the waterproof container 3 is pulled up.

Description

  The present invention relates to a radiation measuring apparatus for measuring radiation in underwater sediment and a radiation measuring method using the apparatus.

  In general, in order to measure the radiation dose of bottom sediment in water, the bottom sediment is collected and taken home and measured. For this reason, there exists a problem that measurement work takes time. For this reason, conventionally, in order to grasp the radiation dose at the bottom of the water, a radioactivity measurement system is known in which an underwater mobile body equipped with a waterproof radiation measurement device and an underwater video camera is towed by a research ship. (For example, refer to Patent Document 1). According to the technique disclosed in Patent Document 1, a video monitor that displays an image from the underwater video camera on a research ship, a position measurement device that measures a current position, and radiation in the water or bottom based on measurement data from the radiation measurement device. It is equipped with a radioactivity display / recording device that displays or records the radiation dose, so that the radiation dose can be grasped while checking the condition of the bottom of the water on the survey ship.

Utility Model Registration No. 3181739

  However, in the conventional radiation measurement system for measuring radiation in the bottom sediment in water, the measurement route is moved once before the measurement work to measure the water depth, and then the length of the dredger cable and the dredger speed After deciding, measurement must be started. Also, at the time of measurement, a worker must be placed on the ship, and only measurement according to the towing route can be performed. For this reason, there exists a problem that work efficiency is bad. In addition, radiation such as radioactive cesium deposited on the bottom of the water is shielded with water between the bottom of the water and the underwater mobile body in which the radiation measurement device is housed, so the coefficient of radiation decreases as the underwater mobile body moves away from the sediment. There is a problem that an accurate dose cannot be measured (see FIG. 8).

  The present invention has been made to solve the above-described problems, and provides a radiation measurement apparatus and a radiation measurement method using the apparatus that can efficiently and accurately measure the radiation dose of the sediment in the water area. For the purpose.

  A radiation measurement apparatus according to claim 1 of the present invention includes a radiation measurement sensor, a control unit that controls the operation of the sensor and stores measurement data measured by the sensor in a storage unit, and the sensor and the control unit. A waterproof container that can be stored in the water and seated on the bottom of the bottom of the water, a weight that is detachably attached to the waterproof container and allows the waterproof container to descend in the water, and one end connected to the waterproof container and the other end And a string that can be adjusted in length, and the radiation measurement sensor is attached while securing an air space between the inner surface of the waterproof container.

  In the radiation measurement apparatus according to claim 1 of the present invention, the radiation measurement sensor, the control means for controlling the operation of the sensor and storing the measurement data measured by the sensor in the storage means, and the sensor and the control means are provided. A waterproof container that can be stored in the water and seated on the bottom of the bottom of the water, a weight that is detachably attached to the waterproof container and allows the waterproof container to descend in the water, and one end connected to the waterproof container and the other end And a string that can be adjusted in length, and the radiation measurement sensor is attached with an air space between the waterproof container and the inner surface of the waterproof container. Bring it to a place, store the radiation measurement sensor and control means in a waterproof container of the radiation measurement device, seal it, attach a weight to this waterproof container, adjust the length of the string to be longer than the water depth, and When the radiation measurement sensor is operated to put the sealed waterproof container in water by the waterproof container is sedimented water by weight, waterproof container bottom lands on the sea bed. At this time, the float on the other end side of the string whose one end is connected to the waterproof container floats on the water surface. When radiation is measured by the radiation measurement sensor, the measurement data is sent to the control means, and the control means stores the measurement data in the storage means. After the measurement time elapses, the operator searches the float by the transportation means and pulls up the radiation measurement apparatus that has been thrown in through the string. For this reason, measurement work can be efficiently performed only by putting the radiation measurement device into a desired measurement place and pulling it up after the measurement time has elapsed. In addition, since the radiation measurement sensor is arranged in the waterproof container separated by the water bottom and the air space, at the time of measurement, the radiation on the bottom of the water is not easily shielded by water, and a lot of radiation reaches the sensor. More accurate measurement is possible.

  In the radiation measuring apparatus according to claim 2 of the present invention, a GPS device for recording position information is housed in the waterproof container, and the measurement position on the water is recorded when the waterproof container is put into water or collected. It is characterized by that.

  In the radiation measuring apparatus according to claim 2 of the present invention, the waterproof container stores a GPS device for recording position information, and the measurement position on the water is recorded when the waterproof container is thrown into or recovered. Thus, an accurate measurement map can be created by associating the measurement result with the measurement position.

  In the radiation measuring apparatus according to claim 3 of the present invention, when the weight of the bottom of the water area is weak, the weight settles with the specific gravity of the waterproof container put into the water area equal to or close to the specific gravity of the bottom material. The speed is reduced, and the weight is set so as to prevent the waterproof container from sinking into the bottom when the waterproof container is settled.

  In the radiation measuring apparatus according to claim 3 of the present invention, when the bottom sediment of the water area is soft, the weight is set so that the specific gravity of the waterproof container put into the water area is equal to or close to the specific gravity of the bottom sediment. When the waterproof container is bottomed, the weight is set so as to prevent the waterproof container from sinking into the bottom material. Even if there is, the waterproof container descends vertically downward, it is possible to make it difficult to wind up mud when the waterproof container is bottomed, it is possible to suppress mud adhesion to the waterproof container, and perform more accurate measurement Can do.

  The radiation measurement apparatus according to claim 4 of the present invention is a portable measurement data in which the control means includes a central processing unit, a memory, and a communication unit, and is housed in a waterproof container and electrically connected to the radiation measurement sensor. A portable control device comprising a collection terminal device, a central processing unit, and a communication unit, operated by an operator outside the waterproof container and controlling the measurement data collection terminal device through communication to operate the radiation measurement sensor It is characterized by comprising a terminal device.

  In the radiation measurement apparatus according to claim 4 of the present invention, the control means includes a central processing unit, a memory, and a communication unit, and is portable measurement data that is housed in a waterproof container and electrically connected to the radiation measurement sensor. A portable control device comprising a collection terminal device, a central processing unit, and a communication unit, operated by an operator outside the waterproof container and controlling the measurement data collection terminal device through communication to operate the radiation measurement sensor By comprising the terminal device, the control terminal device can control the measurement data collection terminal device every time the waterproof container is pulled up after measurement at the measurement location. In addition, the use of a portable terminal device can reduce the size of the entire device. Furthermore, after measurement, the measurement result can be transmitted not only to the memory but also to the outside through communication.

  According to a fifth aspect of the present invention, there is provided a radiation measurement method comprising: a radiation measurement sensor; a control means for controlling the operation of the sensor; and storing measurement data measured by the sensor in a storage means; and the sensor and the control means. A waterproof container that can be stored in the water and seated on the bottom of the bottom of the water, a weight that is detachably attached to the waterproof container and allows the waterproof container to descend in the water, and one end connected to the waterproof container and the other end A radiation measurement method that measures radiation using a radiation measurement device that is equipped with a string that can be adjusted in length and that has a float attached to it, and a radiation measurement sensor that is installed with an air space secured between the inner surface of the waterproof container. A first step of carrying the radiation measuring device to a desired measurement location in the water area by means of transport, and operating the radiation measuring sensor by the control means to put the radiation measuring device into the water; A second step of storing the measurement data measured by the ray measurement sensor in the control means; and a third step of lifting the input radiation measurement device after the measurement time has elapsed and bringing it into the next measurement location. It is a feature.

  In the radiation measurement method according to claim 5 of the present invention, the radiation measurement sensor, the control means for controlling the operation of the sensor and storing the measurement data measured by the sensor in the storage means, and the sensor and the control means are internally provided. A waterproof container that can be stored in the water and seated on the bottom of the bottom of the water, a weight that is detachably attached to the waterproof container and allows the waterproof container to descend in the water, and one end connected to the waterproof container and the other end A radiation measurement method that measures radiation using a radiation measurement device that is equipped with a string that can be adjusted in length and that has a float attached to it, and a radiation measurement sensor that is installed with an air space secured between the inner surface of the waterproof container. A first step of bringing the radiation measuring device to a desired measurement location in the water area by means of transporting means, and operating the radiation measuring sensor by means of the control means to put the radiation measuring device into the water. By having a second step of storing the measurement data measured by the radiation measurement sensor in the control means, and a third step of lifting the input radiation measurement device after the measurement time has passed and carrying it to the next measurement location In the first step, the radiation measuring device is carried to a desired location in the water area by the transport means, and in the second step, the radiation measuring sensor and the control means are accommodated in the waterproof container of the radiation measuring device, and the weight is attached. When the length of the string is adjusted to be longer than the water depth, the radiation measurement sensor is operated by the control means, and the waterproof container is put into the water, the waterproof container sinks in the water by the weight, and the bottom surface of the waterproof container lands on the bottom of the water. At this time, the float on the other end side of the string whose one end is connected to the waterproof container floats on the water surface. Radiation is measured by the radiation measurement sensor, and the measured measurement data is stored in the control means. In the third step, after the measurement time elapses, the floated waterproof container is found out through a string, and the lifted waterproof container is carried to the next measurement location. For this reason, measurement work can be efficiently performed only by putting the radiation measurement device into a desired measurement place and pulling it up after a predetermined time. In addition, since the radiation measurement sensor is arranged in the waterproof container separated by the water bottom and the air space, at the time of measurement, the radiation on the bottom of the water is not easily shielded by water, and a lot of radiation reaches the sensor. More accurate measurement is possible.

  In the radiation measurement method according to claim 6 of the present invention, the control means includes a central processing unit, a memory, and a communication unit, and is portable measurement data stored in a waterproof container and electrically connected to the radiation measurement sensor. A portable control device comprising a collection terminal device, a central processing unit, and a communication unit, operated by an operator outside the waterproof container and controlling the measurement data collection terminal device through communication to operate the radiation measurement sensor In the second step, the measurement data collection terminal device is accommodated in the waterproof container and electrically connected to the radiation measurement sensor, and the operator places the measurement data collection terminal device in the waterproof container through the control terminal device. The radiation data sensor is operated by controlling the measurement data collection terminal device.

  In the radiation measurement method according to claim 6 of the present invention, the control means includes a central processing unit, a memory, and a communication unit, and is portable measurement data stored in a waterproof container and electrically connected to the radiation measurement sensor. A portable control device comprising a collection terminal device, a central processing unit, and a communication unit, operated by an operator outside the waterproof container and controlling the measurement data collection terminal device through communication to operate the radiation measurement sensor In the second step, the measurement data collection terminal device is accommodated in the waterproof container and electrically connected to the radiation measurement sensor, and the operator places the measurement data collection terminal device in the waterproof container through the control terminal device. By controlling the measurement data collection terminal device and operating the radiation measurement sensor, it is necessary to open the waterproof container and take out the measurement data collection terminal device when pulling up the waterproof container Because no measuring operation is efficient.

  The radiation measurement method according to claim 7 of the present invention is characterized in that the radiation measurement device pulled up from the water is transported to another measurement location in the water area, and the second step and the third step are repeated. Yes.

  In the radiation measurement method according to claim 7 of the present invention, the radiation measurement device pulled up from the water is transported to another measurement location in the water area, and the measurement is performed by repeating the second step and the third step. The range can be freely set to be linear or planar.

  In the radiation measurement method according to claim 8 of the present invention, a GPS device for recording position information is stored in the waterproof container, and the measurement position on the water is recorded when the waterproof container is put into water or collected. It is characterized by that.

  In the radiation measuring method according to claim 8 of the present invention, the GPS device for recording position information is stored in the waterproof container, and the measurement position on the water is recorded when the waterproof container is thrown into or recovered. Thus, an accurate measurement map can be created by associating the measurement result with the measurement position.

  A radiation measurement apparatus according to claim 1 of the present invention includes a radiation measurement sensor, a control unit that controls the operation of the sensor and stores measurement data measured by the sensor in a storage unit, and the sensor and the control unit. A waterproof container that can be stored in the water and seated on the bottom of the bottom of the water, a weight that is detachably attached to the waterproof container and allows the waterproof container to descend in the water, and one end connected to the waterproof container and the other end And a string with adjustable length, and a radiation measurement sensor attached with an air space between the inner surface of the waterproof container, so that more radiation reaches the sensor, Accurate measurement is possible, and the radiation dose of the sediment in the water can be measured efficiently and accurately.

  According to a fifth aspect of the present invention, there is provided a radiation measurement method comprising: a radiation measurement sensor; a control means for controlling the operation of the sensor; and storing measurement data measured by the sensor in a storage means; and the sensor and the control means. A waterproof container that can be stored in the water and seated on the bottom of the bottom of the water, a weight that is detachably attached to the waterproof container and allows the waterproof container to descend in the water, and one end connected to the waterproof container and the other end A radiation measurement method that measures radiation using a radiation measurement device that is equipped with a string that can be adjusted in length and that has a float attached to it, and a radiation measurement sensor that is installed with an air space secured between the inner surface of the waterproof container. A first step of carrying the radiation measuring device to a desired measurement location in the water area by means of transport, and operating the radiation measuring sensor by the control means to put the radiation measuring device into the water; A second step of storing the measurement data measured by the ray measurement sensor in the control means, and a third step of lifting the input radiation measurement device after the measurement time has elapsed and bringing it into the next measurement location. Therefore, it is possible to measure the measurement target area simply by repeatedly putting the waterproof container into the measurement place and repeatedly raising it, thereby improving the measurement efficiency. Moreover, since a lot of radiation reaches the sensor, more accurate measurement can be performed in a short time, and the radiation dose of the sediment in the water can be measured efficiently and accurately.

FIG. 1 is an overall perspective view showing a radiation measuring apparatus according to an embodiment of the present invention. (Example 1) FIG. 2 is a partially broken sectional view of the radiation measuring apparatus of FIG. FIG. 3 is a plan view of the radiation measuring apparatus of FIG. 4 (A) and 4 (B) are explanatory views showing an arrival image of gamma rays when the gamma ray measurement sensor is waterproofed and no air space is provided around the gamma ray measurement sensor as in the prior art, and this embodiment, respectively. It is explanatory drawing which shows the arrival image of a gamma ray at the time of providing an air space around a gamma ray measurement sensor based on the structure. FIG. 5 is an explanatory view showing a gamma ray measurement sensor (detector) installed at a predetermined height from the bottom sediment. FIG. 6 is a graph showing the relationship between the radius of the waterproof container and the ratio of the radiation reaching the gamma ray measurement sensor (detector) derived from the theory concerning the radiation of gamma rays. FIG. 7 is an explanatory diagram illustrating an example in which measurement is performed at each measurement location of the pond by the radiation measurement apparatus of FIG. FIG. 8 is a graph illustrating the relationship between the gamma ray energy and the radiation count measured at different heights from the bottom of the water, and is a graph illustrating the water shielding properties.

  For the purpose of efficiently and accurately measuring the radiation dose of the sediment in the water area, a radiation measurement sensor, a control means for controlling the operation of this sensor and storing the measurement data measured by this sensor in the storage means, A waterproof container in which the sensor and the control means are housed and placed in the water and the bottom surface can be seated on the bottom of the water, a weight that is detachably attached to the waterproof container and lowers the waterproof container in water, and one end is Radiation using a radiation measuring device that is connected to a waterproof container and has a string that can be adjusted in length with a float attached to the other end and that has a radiation measurement sensor attached with an air space between the inner surface of the waterproof container A radiation measurement method for measuring a radiation, wherein a radiation measurement device is carried to a desired measurement location in a water area by a transport means, and a radiation measurement sensor is operated by a control means to perform radiation. A second step of throwing the measuring device into the water and storing the measurement data measured by the radiation measuring sensor in the control means; and after the measurement time has elapsed, the charged radiation measuring device is pulled up and carried to the next measurement location. And a control means comprising a central processing unit, a memory, and a communication unit, and a portable measurement data collection terminal device housed in a waterproof container and electrically connected to the radiation measurement sensor; A central processing unit and a communication unit, and a portable control terminal device that operates the radiation measurement sensor by controlling the measurement data collection terminal device through communication that is operated by an operator outside the waterproof container. In the second step, the measurement data collection terminal device is housed in a waterproof container and electrically connected to the radiation measurement sensor. Then, the measurement data collection terminal device in the waterproof container is controlled to operate the radiation measurement sensor, and the radiation measurement device pulled up from the water is transported to other measurement locations in the water area. This was realized by repeating step 3 above.

  Hereinafter, the present invention will be described with reference to embodiments shown in the drawings. 1 and 2 are an overall perspective view and a partially broken sectional view showing a radiation measuring apparatus according to an embodiment of the present invention, respectively. The radiation measuring apparatus 2 according to this embodiment includes a gamma ray measurement sensor (radiation measurement sensor) 4 and an on / off control of the gamma ray measurement sensor 4 that is electrically connected to the gamma ray measurement sensor 4 and is measured by the gamma ray measurement sensor 4. And a portable measurement data collection terminal device (control means) 5A that stores and stores the radiation measurement data in a storage unit (storage means, not shown) and communicates (for example, Bluetooth ( A registered terminal (registered trademark), a wireless LAN, etc.) and a control terminal device (control means) 5B configured to exchange data and command signals with the measurement data collection terminal device 5A, and a GPS logger (GPS device) that records position information. 6 and a block-shaped spacer 7 for holding these equipments 4, 5A, 6 while holding them in a predetermined arrangement position, and for mitigating external impacts, These gear 4, 5A, constructed and a waterproof container 3 for housing to seal the spacer 7 6 is accommodated therein.

  The measurement data collection terminal device 5A stores the measurement data output from the gamma ray measurement sensor 4 and temporarily stored in the storage unit in a file with a file name at each measurement time. The control terminal device 5B is operated by the operator M outside the waterproof container, and controls the measurement data collection terminal device 5A that is sealed and accommodated in the waterproof container 3 through communication. That is, the control terminal device 5B controls the measurement data collection terminal device 5A in the waterproof container 3 through communication to turn on and off the gamma ray measurement sensor 4, or the measurement data stored in the measurement data collection terminal device 5A. The data file can be transferred to the outside. Each of the terminal devices 5A and 5B is a portable terminal device including a central processing unit (CPU, control unit), a memory (storage means, storage unit), and a communication unit, and is a mobile terminal or a portable notebook personal computer. Is used. The gamma ray measurement sensor 4 is placed at a position immediately above the sediment in the water for a certain period of time, and emits radiation from the bottom mud, that is, from radioactive materials including radioactive cesium (Cs-134, Cs-137) in the bottom. It is designed to measure the value of gamma rays. The gamma ray measurement sensor 4 is turned on and off by a command signal from the measurement data collection terminal device 5A, and outputs the measured data to the measurement data collection terminal device 5A.

  That is, more specifically, (1) the control terminal device 5B is used to control the measurement data collection terminal device 5A in the waterproof container 3, the measurement software is started, and (2) the waterproof container 3 is It is dropped into the water at the measurement location (measurement is in progress at this time), and (3) waits until the measurement time (4 minutes in the present embodiment) ends, and then the data storage is completed. (4) Pull up the waterproof container 3.

  The GPS logger 6 can measure and record the current position with GPS (Global Positioning System) at regular intervals, and can know the movement route later. Although the GPS logger 6 can measure and record the current position on the ground, it cannot be measured underwater. Therefore, the data immediately before the waterproof container 3 is put into the water or the data just collected after being collected from the water is It is the data of the measurement position at. That is, when the time before and after the time measured by the gamma ray measurement sensor 4 is associated with the recording time of the GPS logger 6, the measurement position is determined. Thus, an accurate measurement map can be created by associating radiation measurement data with a measurement position.

  The waterproof container 3 includes a container body 8 made of a transparent acrylic plate having a cylindrical shape with a bottom, and a lid body 9 that is covered with an upper opening of the container body 8 and seals the inside. The lid body 9 is mounted on an upper end flange 8A formed with an outer peripheral edge projecting outward from the upper end opening of the container body 8 via an annular packing 10, and is fastened with a fastener 11 that is screwed at equal intervals in the circumferential direction. (4 places in this embodiment) are sealed. Inside the container body 8, both longitudinal ends of the block spacer 7 in which the equipments 4, 5 </ b> A, and 6 are housed are accommodated in contact with the inner surface of the container body 8. When the waterproof container 3 has the spacer 7 in which the respective equipments 4, 5 </ b> A, and 6 are disposed accommodated in the container body 8 and the lid body 9 is in close contact with the container body 8 and sealed, the waterproof container 3 is poured into water and the bottom surface is It is designed to sit on the underwater sediment. The spacer 7 is formed with a pocket having an upper opening corresponding to the arrangement of the equipments 4, 5 A and 6, and the equipments 4, 5 A and 6 are accommodated in these pockets so that they can be taken in and out from above. The spacer 7 is inserted into and removed from the container body 8 by the operator M.

  The gamma ray measurement sensor 4 is disposed on the axis C of the cylindrical container body 8 at a predetermined height h. From the graph derived from the theory shown in FIG. 6, in this embodiment, the radius r of the container body 8 used in the experiment is 10 cm and the height h of the gamma ray measurement sensor 4 is 5 cm. Higher h is preferable. That is, it is preferable to increase the installation height h within a range where the device does not become extremely large. Thus, in this embodiment, a predetermined height h is secured from the wall surface of the container main body 8 at a uniform position (on the axis C) and from the bottom surface, and around the gamma ray measurement sensor 4 in the circumferential direction and downward. The air space S is secured so that accurate measurement accuracy can be obtained in a short time. By securing the air space S, gamma rays reach from a wide range of sediment (see (B) in FIG. 4), so that the gamma ray measurement time can be shortened. In FIG. 4A, the gap between the bottom sediment and the gamma ray measurement sensor 104 is filled with water without waterproofing the gamma ray measurement sensor 104 and providing an air space around the gamma ray measurement sensor 104 as in the prior art. It is explanatory drawing which shows the arrival image of the gamma ray in the case of being. As can be seen from FIG. 4A, when only the gamma ray measurement sensor 104 is waterproof and there is water between the bottom sediment, the radiation around the gamma ray measurement sensor 104 is blocked by the bottom sediment radiation. To obtain accurate measurement accuracy, it is necessary to measure for a long time. On the other hand, as shown in FIG. 4B, the gamma ray measurement sensor 4 according to the present embodiment is housed in the waterproof container 3, and the air around the gamma ray measurement sensor 4 is in the circumferential direction and downward. Since the space S is secured, those that shield radiation are excluded. For this reason, measurement time can be shortened. A string (not shown) is connected to the upper end of the gamma ray measurement sensor 4 and is used when the gamma ray measurement sensor 4 is taken out from the spacer 7 after being stored in the spacer 7.

In this embodiment, the arrangement of the gamma ray measurement sensor 4 on the container body 8 was obtained by theoretical interpretation.
First, when the radioactive material exists uniformly on the ground surface, as shown in FIG. 5, the radiation that reaches the point of height h is expressed by the following formula (Equation 1), and the energy of the radiation is around 0.5 MeV. In this case, the attenuation coefficient μ is proportional to the density of the substance, and is approximately 0.01 for air and 8.55 for water.

  When the air space S is provided around the detector (gamma ray measurement sensor 4) by the cylindrical waterproof container 3, the ratio of the amount of radiation (air / water) reaching the detector (gamma ray measurement sensor 4) is expressed by the above formula. It is obtained from (Equation 1) as shown in the graph of FIG. For example, when an air space S is provided by a cylindrical waterproof container 3 having a radius of 10 cm and a detector (gamma ray measurement sensor 4) is installed on the axis C at a height of 5 cm from below, about 1.9 times as much radiation arrives. Measurement efficiency is improved.

  A handle 13 is provided between the fasteners 11 on the lid 9 of the waterproof container 3. A string 15 having a float 14 connected to the tip is coupled to the handle 13. The length of the string 15 can be adjusted according to the depth of the water area. The string 15 can be pulled up from the water when the waterproof container 3 is bottomed in the water and the float 14 is floated on the surface of the water and is pulled while holding the float 14 side.

  A weight 20 is detachably attached to the waterproof container 3. The weight 20 is constituted by a plurality of weight pieces 20A and a band body 21 through an insertion hole formed in the weight piece 20A. The weight 20 is formed by winding a belt body 21 inserted around a desired number of weight pieces 20A through insertion holes around the outer periphery of the container body 8 and projecting the weight piece 20A to the outer periphery of the lower end of the container body 8. It is placed on the part 8B and attached to the container body 3. According to the number of weight pieces 20A, the weight 20 is attached so that the weight of the weight 20 can be adjusted by adjusting the number of weight pieces 20A according to the specific gravity of the sealed waterproof container 3 in which equipment is housed. It is done. That is, when the waterproof container 3 lands according to the bottom sediment of the water area, the weight 20 makes the specific gravity of the waterproof container 3 equal to or close to the specific gravity of the bottom sediment so as to reduce the impact at the time of landing. It is like that. That is, in the case of a soft bottom, the waterproof container 3 is configured to settle at a lower speed. In the case of the present embodiment, in consideration of the soft bottom, the specific gravity of the waterproof container 3 equipped with the weight 20 is set to be about 1.1 to 1.2. In addition, when there is no weight 20, since the air chamber is formed in the sealed waterproofing container 3, it does not sink in water. For this reason, even if the bottom sediment of the measurement target place in the water area is soft or slender, the waterproof container 3 descends vertically downward, and it is possible to make it difficult to wind up mud when the waterproof container 3 reaches the bottom, The adhesion of mud to the waterproof container 3 is suppressed, and more accurate measurement can be performed.

  The radiation measuring apparatus 2 according to the above embodiment, for example, when measuring the radiation dose of the sediment in the water area W such as a pond shown in FIG. The equipment 4, 5A, 6, the spacer 7, the container main body 8, and the lid body 9 are carried in, and the GPS logger 6 is operated to check the position and time. Then, the operator M switches on the gamma ray measurement sensor 4 and the measurement data collection terminal device 5A to start communication software, and the equipments 4, 5A and 6 are accommodated in the spacer 7, and the spacer 7 is stored in the container body. 8 and the waterproof container 3 is sealed with a lid 9. Next, the worker M operates the control terminal device 5B, and controls the measurement data collection terminal device 5A by wireless LAN or Bluetooth (registered trademark) communication means. The control terminal device 5B is configured to turn on / off the measurement software and store the measurement data file through the measurement data collection terminal device 5A. The measurement software is capable of timer measurement and is set to “measure for t seconds after start”. That is, the gamma-ray measurement sensor 4 is set to perform a measurement operation for a desired time t seconds after the operation is started. Since the gamma ray measurement sensor 4 does not have an automatic storage function for the measured data, the measured measurement data is output to the measurement data collection terminal device 5A and stored in the memory of the measurement data collection terminal device 5A for each measurement time. Is saved as a file with the file name. That is, the sealed waterproof container 3 is put into the water of the measurement location, the gamma ray measurement sensor 4 measures the specified measurement time (4 minutes in this embodiment), and the measurement data is transmitted to the measurement data collection terminal device 5A. Then, the measurement data collection terminal device 5A stores the measurement data received from the gamma ray measurement sensor 4 in a file of a memory (not shown). This file is created for each measurement time. When the underwater waterproof container 3 is collected, the float 14 is searched for by a ship (not shown), and the string 15 is pulled to collect it on the ship.

  Next, a radiation measurement method using the radiation measurement apparatus 2 according to the above embodiment will be described based on the operation of the radiation measurement apparatus 2. In the radiation measurement method using the radiation measurement apparatus 2 according to the present embodiment, first, in a first step S1, the worker M uses a ship (transport means, not shown) to measure a desired measurement position (initially) in the water area W. The measurement device 2 is brought into the radiation measurement device 2.

  Next, in the second step S2, the worker M switches on the gamma ray measurement sensor 4, the measurement data collection terminal device 5A, the wireless LAN router (not shown), and the GPS logger 6 to be in an operating state, and performs communication. Start the software. The gamma ray measurement sensor 4, the measurement data collection terminal device 5 </ b> A, and the GPS logger 6 are housed in the container body 8 through the spacer 7, and the waterproof container 3 is sealed with the lid 9. Then, the worker M operates the measurement data collection terminal device 5A by the control terminal device 5B and starts measurement of the gamma ray measurement sensor 4 through the measurement software. At this time, the measurement may be started after a predetermined time has elapsed in consideration of the bottoming time. Thereafter, the waterproof container 3 is put into water from a ship (not shown). The waterproof container 3 thrown into the water has a weight 20 attached to the lower side, and when the weight of the weight 20 is adjusted and the bottom of the water area is weak, the specific gravity of the waterproof container 3 thrown into the water area W is Since the specific gravity of the bottom material is equal to or close to the specific gravity of the bottom material (in this embodiment, the specific gravity of the waterproof container 3 is set to 1.1 to 1.2), the waterproof container 3 sinks at a low speed. For this reason, when the waterproof container 3 is settled, the waterproof container 3 is prevented from sinking into the bottom material. For this reason, the waterproof container 3 slowly settles with the bottom face directed downward, and even if the bottom material is soft, the waterproof container 3 settles gently without rolling up mud. The gamma ray measurement sensor 4 transmits the measured measurement data to the measurement data collection terminal device 5A for the designated measurement time (4 minutes in the present embodiment). The measurement data collection terminal device 5A temporarily stores measurement data received from the gamma ray measurement sensor 4 in a memory (not shown) and saves it in a file. At this time, although the GPS logger 6 can measure and record the current position on the ground, it cannot be measured underwater. Therefore, the data immediately before the waterproof container 3 is put into the water or the water just after the collection recovered from the water. This data becomes the measurement position data. During the measurement time (4 minutes in this embodiment), the worker M stands by on the ship. When this predetermined measurement time elapses, the measurement software ends the measurement. When finished, the file in which the measurement data is saved is saved as a file at the measurement location (measurement time).

  Next, in a third step S3, after waiting on a ship (not shown) for a time corresponding to the measurement time of the gamma ray measurement sensor 4, the float 14 is searched for, the string 15 is pulled, and the prevention container 3 is collected on the ship. Then, the worker M moves to the next measurement place on the ship, and again controls the measurement data collection terminal device 5A of the waterproof container 3 sealed by the control terminal device 5B, sets the measurement work, The waterproof container 3 is thrown into water at the measurement location. Thus, when the waterproof container 3 is pulled up to the ship, the measurement data collecting terminal device 5A of the sealed waterproof container 3 can be controlled and measured without opening the lid 9. For this reason, it can move to the next measurement point quickly. When the measurement is completed at one point, the process is completed in the third step S3. When measuring at a plurality of measurement points, the second step S2 and the third step S3 are repeated, the ship goes to the next measurement point, and the raised radiation measurement device is transported to another measurement point in the water area. The measurement process for each measurement location is collected by repeating the charging process of operating the radiation measurement sensor to put the waterproof container into the water and the lifting process of lifting the waterproof container after the measurement time has elapsed. It has become. As described above, since the measurement is performed by repeatedly inserting and collecting the waterproof container 3 sealed for each measurement point in the water area W, the measurement range can be freely set to be linear or planar. If the measurement data of the radiation at each measurement position measured by the gamma-ray measurement sensor 4 is associated with the position information of the GPS logger 6 and the recording time of this position information, the radiation measurement data is associated with the measurement position and is accurate. A measurement map can be created. Thus, in the radiation measurement method using the radiation measurement apparatus 2 according to the present embodiment, the measurement work is efficiently performed only by inserting the waterproof container 3 at a desired measurement location and pulling up after a predetermined measurement time has elapsed. be able to. Further, since the gamma ray measurement sensor 4 is arranged in the waterproof container 3 so as to be separated from the bottom of the water and the air space S, the radiation of the bottom of the water is not easily shielded by water during measurement, and the radiation reaches the sensor accurately. Cheap. For this reason, the input for measurement and the collection | recovery of measurement data can be performed shifting time, and the measurement of the radiation dose of the bottom sediment in water can be performed efficiently and correctly.

  In the above embodiment, the GPS logger 6 is accommodated in the waterproof container 3, but the invention is not limited to this. The worker M, not the waterproof container 3, carries the GPS logger 6 and inserts the waterproof container 3. The position data at the time may be recorded by the worker M, and later added together with the radiation measurement data. In the above embodiment, the measurement data is collected using the measurement data collection terminal device and the control terminal device. However, the present invention is not limited to this, and the display unit is provided in the measurement data collection terminal device. The measurement data displayed on the display unit through a transparent acrylic container may be written by the operator, or the measurement data collection terminal device can be exchanged through communication with an external center server. You may make it transmit to. Also, a window that can be opened and closed is formed in the waterproof container, and when the waterproof container is lifted from the water, the window is opened and measurement data is transmitted to the external center server through the communication unit of the measurement data collection terminal device. Also good. Further, at the time of pulling up, measurement may be performed by opening the window and operating the measurement data collection terminal device. In this case, measurement can be performed with only one terminal device. The control terminal device may be a Bluetooth (registered trademark) keyboard.

2 Radiation measurement device 3 Waterproof container 4 Gamma ray measurement sensor (radiation measurement sensor)
5A Measurement data collection terminal device (control means)
5B Control terminal device (control means)
14 Floating 15 String 20 Weight S Air space

Claims (8)

  A radiation measurement sensor, a control unit that controls the operation of the sensor and stores measurement data measured by the sensor in a storage unit, and the sensor and the control unit are housed inside and put into water so that the bottom surface is underwater A waterproof container that can be seated on the bottom, a weight that is detachably attached to the waterproof container and that allows the waterproof container to descend in water, and a string whose one end is connected to the waterproof container and a float is attached to the other end, the length of which can be adjusted And a radiation measuring device, wherein the radiation measuring sensor is attached while securing an air space between the inner surface of the waterproof container.   The radiation measurement according to claim 1, wherein a GPS device for recording position information is stored in the waterproof container, and a measurement position on the water is recorded when the waterproof container is put into water or collected. apparatus.   When the bottom sediment of the water area is soft, the weight reduces the sedimentation speed by making the specific gravity of the waterproof container thrown into the water area equal to or close to the specific gravity of the bottom sediment, The radiation measuring device according to claim 1, wherein the radiation measuring device is set to a weight that prevents the container from sinking into the bottom sediment.   The control means includes a central processing unit, a memory, and a communication unit, and is a portable measurement data collection terminal device housed in a waterproof container and electrically connected to the radiation measurement sensor, the central processing unit, and the communication unit And a portable control terminal device that is operated by an operator outside the waterproof container and controls the measurement data collection terminal device through communication to operate the radiation measurement sensor. The radiation measuring apparatus according to any one of claims 1 to 3. A radiation measurement sensor, a control means for controlling the operation of the sensor and storing measurement data measured by the sensor in a storage means, and the sensor and the control means are housed inside and put into water so that the bottom surface is the bottom of the water A waterproof container that can be seated on the quality, a weight that is detachably attached to the waterproof container, and lowers the waterproof container in water; a string that has one end connected to the waterproof container and a float attached to the other end, the length of which can be adjusted; A radiation measurement method for measuring radiation using a radiation measurement device in which an air space is secured between the radiation measurement sensor and the inner surface of the waterproof container,
The first step of bringing the radiation measuring device to the desired measurement location in the water area by the transport means, the radiation measuring sensor is operated by the control means, the radiation measuring device is put into the water, and the measurement data measured by the radiation measuring sensor is controlled. A radiation measurement method comprising: a second step of storing in a means; and a third step of pulling up the input radiation measurement device and carrying it to the next measurement location after the measurement time has elapsed.   The control means includes a central processing unit, a memory, and a communication unit, and is a portable measurement data collection terminal device housed in a waterproof container and electrically connected to the radiation measurement sensor, the central processing unit, and the communication unit And a portable control terminal device that is operated by an operator outside the waterproof container and controls the measurement data collection terminal device through communication to operate the radiation measurement sensor. The measurement data collection terminal device is accommodated in the waterproof container and electrically connected to the radiation measurement sensor, and the operator controls the measurement data collection terminal device in the waterproof container through the control terminal device, and the radiation measurement sensor. The radiation measuring method according to claim 5, wherein the radiation measuring method is operated.   The radiation measurement method according to claim 5 or 6, wherein the radiation measurement device pulled up from the water is transported to another measurement location in the water area, and the second step and the third step are repeated.   8. The waterproof container stores a GPS device for recording position information, and records the measurement position on the water when the waterproof container is put into water or collected. The radiation measuring method according to claim 1.