JP2005134239A - Radiation measuring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a gas sucking speed difference in a measuring chamber, to make the position dependency of sensitivity smaller, and to perform high-accuracy radiation measurement in a radiation measuring apparatus which sucks ions generated in a gas inside the measuring chamber by ionization action of the radiation of an object to be measured, detects an ionization current and measures the radiation. <P>SOLUTION: The quantity of the radiation is measured by blowing a gas from a gas blowout apparatus 17 to the periphery of the object 1 to be measured put in the measuring chamber 2, agitating the gas 5 inside the chamber 2, sucking the agitated gas 5 with a sucking apparatus 3 and circulating it in a gas circulation course 8, collects the ions in the gas with an ion collector 9 provided in the middle of the course 8, measures the ionization current with an ionization-current measuring device 6, and performing an arithmetic operation with a data processor 7 on the basis of the value of this ionization current. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a radiation measuring apparatus that stores a radiation measurement object in a measurement chamber, collects ions generated by the ionizing action of radiation, and measures the radiation dose of the measurement object by measuring an ionization current due to ionization. .

  Conventionally, as a radiation measurement device, gas is ionized by the ionizing action of radiation, ions generated by ionization are sucked together with the gas, ionization current due to ions is detected with an electrode applied with an electric field, and the radiation dose is measured from the intensity. There is something like that.

As an example, the conventional one shown in FIG. 9 has been considered.
In FIG. 9, reference numeral 1 denotes a radiation measurement object, 2 denotes a measurement chamber for housing the measurement object 1, and 3 a to 3 d are connected to, for example, four locations around the measurement chamber 2 at equal intervals via pipes 4 a to 4 d. , A suction device for sucking the gas 5 in the measurement chamber 2, 6 a to 6 d are ionization current measurement devices provided in the middle of the pipes 4 a to 4 d between the suction devices 3 a to 3 d and the measurement chamber 2, and 7 is each This is a data processing device to which ionization current values measured by the ionization current measuring devices 6a to 6d are input (see, for example, Patent Document 1).

  In such a radiation measurement device, the gas 5 in the measurement chamber 2 containing ionized ions ionized by the radiation of the measurement object 1 is sucked by the suction devices 3a to 3d, and the ionization current measurement devices 5a to 5d are used. The ionization current due to ions is measured, and the radiation amount of the measurement object 1 is measured by the data processing device 6 based on the measured ionization current.

On the other hand, another conventional means is also considered as shown in FIG.
In FIG. 10, reference numeral 1 denotes a radiation measurement object, for example, a cylindrical object closed on one side, 2 a measurement chamber for housing the measurement object 1, and 8 a gas circulation path connected to the measurement chamber 2. The ion collecting device 9 having an electrode in the middle of the circulation path, the suction device 3 for sucking the gas 5 in the measurement chamber 2 into the gas circulation path 8, and the particle collecting device 10 are provided.

  11 is a pipe-like gas ejection device provided inside the measurement chamber 2, the tip of which opens toward the measurement object 1, and 12 is provided outside the measurement chamber 2, and blows gas to the gas ejection device 11. A gas blower, 6 is an ionization current measurement device that measures an ionization current from ions collected by the ion collection device 9, 7 is a data processing device to which an ionization current value measured by the ionization current measurement device 6 is input, and 13 is This is a voltage supply device that applies a voltage to the electrodes of the ion collector 9 (see, for example, Non-Patent Document 1).

In such a radiation measurement device, the gas 5 in the measurement chamber 2 containing ionized ions ionized by the radiation of the measurement object 1 is sucked by the suction device 3 and along the arrow X direction in the gas circulation path 8. The ions are collected by the ion collector 9 provided in the middle of the circulation path.
The collected ions are measured for ionization current by the ionization current measuring device 6, and the data processing device 7 performs arithmetic processing based on the measured ionization current to measure the radiation dose of the measurement object 1.

The gas flowing through the gas circulation path 8 is trapped by ions and then returned to the measurement chamber 2 through the particle collecting device 10.
In the measurement chamber 2, the gas sent from the gas blower 12 is blown into the cylinder of the measurement object 1 through the gas blower 11, so that the gas staying in the cylinder is forced into the gas circulation path 8. To circulate.
JP2003-194946A (P14, FIG. 9) Proceedings of the Atomic Energy Society of Japan "Autumn of 2003" (P64)

  However, in the case of the conventional radiation measuring apparatus as shown in FIG. 9, the gas 5 in the measurement chamber 2 is sucked by the suction devices 3a to 3d provided at equal intervals around the measurement chamber 2, but the measurement is performed. The gas suction speed difference in the chamber 2 is large, and it is difficult to suck the gas in the vicinity of the surface of the measurement object 1 at a uniform speed.

In particular, in the case of a measurement object having a large size and various shapes, a gas containing ions stays in a corner of the measurement chamber 2 or a recess of the measurement object 1 and can be more evenly sucked. It becomes difficult.
For this reason, the sensitivity position dependence with respect to the measuring object 1 becomes large, and highly accurate radiation measurement cannot be performed.

  On the other hand, in the case of the conventional radiation measuring apparatus shown in FIG. 10, the gas 5 in the measuring chamber 2 is agitated by partial blowing by the gas jetting apparatus 11 to reduce a part of the sensitivity difference. Although a measurement object having a simple shape such as a cylindrical shape has a certain effect, it cannot be expected to be very effective for a measurement object having a large size and a complicated shape. As in the example, the retention of gas containing ions occurs, the sensitivity position dependency on the measurement object 1 increases, and highly accurate radiation measurement cannot be performed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a radiation measuring apparatus capable of performing highly accurate radiation measurement even on a large and complicated measuring object.

  In order to achieve the above-mentioned object, the invention of the radiation measuring apparatus according to claim 1 includes a measurement chamber for storing a measurement object of radiation together with gas, and the measurement including ionized ions ionized by radiation of the measurement object. A gas circulation path for circulating a gas in the room; an ion collector provided in the gas circulation path; an ionization current measurement apparatus for measuring an ionization current from the ions collected by the ion collection apparatus; and the ionization current measurement apparatus A data processing device for calculating and processing the radiation dose of the measurement object based on the ionization current measured by the method, and surrounding the measurement object stored in the measurement chamber from the periphery, It is characterized by comprising a plurality of gas jetting devices to be blown and a gas blower sending gas to the gas jetting device.

  Further, the invention of the radiation measuring apparatus according to claim 4 circulates the gas in the measuring chamber containing the ionizing ions ionized by the radiation of the measuring object and the measuring chamber for storing the measuring object of the radiation together with the gas. A gas circulation path, a charge collection device provided in the gas circulation path, a charge measurement device for measuring a charge amount from an accumulated charge amount collected by the charge collection device, and a charge measured by the charge measurement device. A data processing device for calculating and processing the radiation dose of the measurement object, and a plurality of gas ejection devices which are provided so as to surround the measurement object housed in the measurement chamber from the surroundings and blow gas to the measurement object And a gas blower that sends gas to the gas jetting device.

  According to the radiation measuring apparatus of the present invention, it is possible to perform highly accurate radiation measurement even on a large and complicated measuring object.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description of the embodiment, the same parts as those in the conventional radiation measuring apparatus shown in FIGS. 9 and 10 are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 1 is a diagram showing a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a measurement object of radiation such as a cylindrical container closed on one side, and reference numeral 2 denotes a measurement chamber for storing the measurement object 1. , 8 is a gas circulation path having one end connected to the gas outlet side of the measurement chamber 2 via the gas converging device 14 and the other end connected to the gas inlet side of the measurement chamber 2 via the gas diffusion device 15. Gas circulation with an ion collector 9 having an electrode in the middle of the gas circulation path 8, a suction device 3 that sucks the gas 5 consisting of air in the measurement chamber 2 into the gas circulation path 8, a particle collection device 10, and the suction device 3. A blower device 16 is provided for circulating the gas 5 in the measurement chamber 2 sucked into the path 8 through the gas diffusion device 15 into the measurement chamber 2 again.

  6 is an ionization current measuring device that measures the ionization current from the ions collected by the ion collector 9, 7 is a data processing device to which the ionization current value detected by the ionization current measuring device 6 is input, and 13 is the ion collector. 9 is a voltage supply device for applying a voltage to nine electrodes.

  Reference numeral 17 denotes a plurality of nozzle-like gas ejection devices that are detachably attached to the wall of the measurement chamber 2 so as to surround the measurement object 1 housed in the measurement chamber 2 from the periphery thereof. The gas outlet is attached to the measuring object 1 so that its position can be freely changed.

  FIG. 1 shows a state in which three gas ejection devices 17 are attached to one wall of the measurement chamber 2 in plan view, and a total of 12 gas ejection devices 17 are attached to the four walls. A gas ejection device is also attached to the ceiling wall, and the number, attachment position, etc. are determined as necessary.

  In addition, each gas ejection device 17 is placed in the measurement chamber 2 so as to be in an optimum position and direction while being adjusted toward a place where an operator enters the measurement chamber 2 and is expected to retain a gas containing ions in advance. It can be attached efficiently by attaching and fixing to the wall.

  18 is connected to each gas ejection device 17, and has a flexible blow pipe that follows the position adjustment operation of the gas ejection device 17. 19 is a gas that is sent to the gas ejection device 17 via each blow pipe 18. A gas blower 20, which connects the gas blower 19 and a plurality of gas ejection devices 17 together, individually controls the opening and closing of the amount of air sent from the gas blower 19 to each gas ejection device 17. An opening / closing device 21 having an opening / closing valve is an opening / closing control device 21 for controlling the opening / closing of the opening / closing valve of the opening / closing device 20.

  Reference numeral 22 denotes a rotating device such as a turntable which is provided in the measurement chamber 2 and can place the measurement object 1 and can be rotated while being placed. Reference numeral 23 denotes a rotation angle detection which detects the rotation angle of the measurement object 1. A device 24 is provided inside the wall of the measurement chamber 2, and a rectifying plate for smoothly flowing the gas circulated and blown into the measurement chamber 2 from the gas circulation path 8 in the measurement chamber 2, 25 is a gas blower It is the particle | grain collection apparatus provided in 19 gas intake ports.

Next, the operation of the radiation measuring apparatus according to this embodiment will be described.
The gas 5 containing ionized ions ionized by radiation on the surface of the measurement object 1 housed in the measurement chamber 2 is sucked by the suction device 3, converged by the gas converging device 14, and arrow X in the gas circulation path 8. It is circulated along the direction.

The gas 5 sent into the gas circulation path 8 passes through an ion collector 9 provided in the middle of the circulation path, where ions contained in the gas are collected.
The collected ions are measured for the ionization current by the ionization current measuring device 6, and the data processing device 7 performs arithmetic processing based on the measured ionization current to measure the radiation dose of the measurement object 1.

  On the other hand, when the gas 5 circulates in the gas circulation path 8, the gas blowing means 19 generates high-speed gas, which is sent to the plurality of gas ejection devices 17 through the opening / closing valve of the opening / closing device 20 and the blowing pipe 18. A high-speed gas is blown around the measurement object 1 from the nozzle tip.

  The high-speed gas blown from the gas ejection device 17 collides with the surface of the measurement object 1, the ions generated on the surface of the measurement object 1 are separated, and the gas 5 in the measurement chamber 2 is stirred. The stirred gas 5 is sucked by the suction device 8 and circulated in the gas circulation path 8 through the gas converging device 14.

  The gas flowing through the gas circulation path 8 is collected through the particle collecting device 10 after collecting the ions, and returned to the measurement chamber 2 again after being diffused in a wide range by the gas diffusion device 15 by the gas blower 16. .

  As described above, according to the radiation measuring apparatus according to the present embodiment, the ions generated on the surface of the measurement object 1 are separated by the high-speed gas blown from the gas ejection device 17, and the gas 5 in the measurement chamber 2 is removed. Since the mixture is stirred and transferred to the ion collector 9 provided in the gas circulation path 8, there is no stagnation of ions in the measurement chamber 2, and compared with only the gas flow diffused by the gas diffusion device 15. Therefore, the circulation of ions becomes smoother, and the difference in ion measurement efficiency is reduced.

  High-speed gas is blown by a plurality of gas ejection devices 17 provided around the measurement object even on a measurement object that is particularly large and has a complicated shape, thereby eliminating stagnant ions and smoothing the circulation of ions. Therefore, the sensitivity position dependency with respect to the measurement object 1 is reduced, and highly accurate radiation measurement can be performed.

  When performing radiation measurement of the measurement object 1, the measurement object 1 is rotated by the rotation device 22, the rotation angle of the measurement object 1 is detected by the rotation angle detection device 23, and the detection signal is sent to the opening / closing control device 21. The gas ejection amount from each gas ejection device 17 is controlled by adjusting the opening / closing valve of the opening / closing device 20 by the opening / closing control device 21 for each predetermined angle of the measuring object 1.

  For example, when there is no gas ejection from the gas ejection device 17 provided on the wall of the measurement chamber 2 to which the gas converging device 14 is attached and the rotation angle of the measurement object 1 is 315 to 45 degrees, the gas diffusion means 15 The gas was ejected only from the gas ejection means 17 provided on the wall of the measurement chamber 2 to which the gas diffusion means 15 was attached. When the rotation angle was 45 to 135 degrees, the gas was rotated 90 degrees from the wall of the measurement chamber 2 to which the gas diffusion means 15 was attached. Gas was ejected only from the gas ejection device 17 attached to the surface, and when the rotation angle was 135 to 225 degrees, it was attached to the surface rotated 270 degrees from the wall of the measurement chamber 2 to which the gas diffusion means 15 was attached. Control is performed so that gas is ejected only from the gas ejection device 17.

  In this way, by rotating the measurement object 1 and controlling the amount of gas ejected from the gas ejection device 17 according to the rotation angle, the accumulated ions are eliminated even in the case of a measurement object having a more complicated shape. Therefore, the sensitivity position dependency with respect to the measurement object 1 is reduced, and radiation measurement with high accuracy can be performed.

  Furthermore, only when gas is ejected from the gas ejection device 17, ions are collected by the ion collector 9 provided in the gas circulation path 8 to measure the ionization current. When no gas is ejected from the gas ejection device 17, the ionization current is measured. If, for example, the average value is calculated from the measured values of the multiple ionization currents and then the radiation dose is calculated from the measured values, the difference in sensitivity can be reduced because it can be efficiently calculated from the current values collected. Accuracy is improved.

For example, when a cylindrical container-shaped measurement object opened only on one side is placed sideways with the opening facing the gas diffusion device 15 and the angle is set to 0 degrees, the rotation angle of the measurement object 1 is 340 degrees to 20 degrees. In this case, gas is ejected only from the gas ejection means 17 provided on the wall of the measurement chamber 2 to which the gas diffusion device 15 is attached, and when the rotation angle is 70 degrees to 110 degrees, the measurement is performed with the gas diffusion means 15 attached. When the gas is ejected only from the gas ejection device 17 attached to the wall rotated 90 degrees from the wall of the chamber 2 and the rotation angle is 160 degrees to 200 degrees, from the wall of the measurement chamber 2 to which the gas diffusion means 15 is attached When gas is ejected only from the gas ejection device 17 attached to the wall rotated 180 degrees and the rotation angle is 250 to 290 degrees, the gas is rotated 270 degrees from the wall of the measurement chamber 2 to which the gas diffusion means 15 is attached. It was only gas from the gas discharge device 17 attached to the wall so as to jet.
Even if it does in this way, a sensitivity difference becomes small and a measurement precision improves more.

  Next, a second embodiment of the present invention will be described with reference to FIG. In the following description of the embodiment, the same parts as those in the first embodiment of the present invention shown in FIG.

  In FIG. 2, reference numeral 26 denotes an imaging device such as a video camera that captures an image of the measurement object 1 placed on the rotating device 22 in the measurement chamber 2, and the measurement object 1 captured by the imaging device 26. The video signal is input to the open / close control device 21.

  In the radiation measuring apparatus according to the present embodiment, the shape of the measuring object 1 photographed by the photographing apparatus 26 is sent to the open / close control device 21 as a video signal, and the rotation angle of the measuring object 1 is detected from this shape. The amount of gas ejection from each gas ejection device 17 is controlled by adjusting the opening / closing valve of the opening / closing device 20 by the opening / closing control device 21 for each angle of the measuring object 1 determined in advance based on this rotation angle.

  Also in the present embodiment, the rotation angle of the measurement object 1 is detected from the video signal of the measurement object 1, and the gas ejection amount from the gas ejection device 17 is controlled in accordance with the rotation angle, thereby making it more complicated. Even in the case of a measurement object having a shape, the staying ions are eliminated, and the circulation of ions is smooth. Therefore, the sensitivity position dependency on the measurement object 1 is reduced, and highly accurate radiation measurement can be performed.

Next, a third embodiment of the present invention will be described with reference to FIG.
In FIG. 3, 27 is a first particle collection device provided on the outlet side of the measurement chamber 2 along the flow of the gas 5 in the measurement chamber 2, and 28 is a downstream side of the ion collection device 9 in the gas circulation path 8. And a second particle collecting device having a collection target particle size smaller than the collection target particle size of the first particle collection device 27.

In general, as the particles contained in the gas 5 flowing through the gas circulation path 8, for example, the following three types can be considered in order of increasing particle diameter.
First, dust particles adhering to the measurement object 1, then aerosol drifting in the air, and finally cluster ions to which ions generated by the ionizing action of radiation are attached.

Here, the collection particle size of the first particle collection device 27 is set to match the dust particles, and the collection particle size of the second particle collection device 28 is set to match the aerosol.
In this way, the first particle collection device 27 increases the transmittance of the cluster ions as much as possible, and reliably collects dust particles that are a factor of sensitivity variation, and the second particle collection device 28 measures the measurement environment. It collects aerosols that adversely affect the environment and efficiently collects ions, improving sensitivity and performing highly accurate radiation measurement.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
In FIG. 4, reference numeral 29 denotes a charge collection device provided in the middle of the gas circulation path 8 in place of the ion collection device in the first embodiment, and includes a conductor 30 insulated inside. Reference numeral 31 is a charge measuring device connected to the charge collecting device 29 and measures the charge accumulated in the conductor 30, and 32 is connected to the charge measuring device 31 and measured based on the charge amount measured by the charge measuring device 31. 1 is a data processing device that performs arithmetic processing on the radiation dose of an object 1.

  In the radiation measuring apparatus according to the present embodiment, the gas 5 containing ionized ions ionized by radiation on the surface of the measurement object 1 housed in the measurement chamber 2 is sucked by the suction device 3 and the gas focusing device 14. And is circulated in the gas circulation path 8 along the arrow X direction.

  The gas 5 sent into the gas circulation path 8 is accumulated as a charge in the conductor 30 of the charge measuring device 29 provided in the middle of the circulation path. The accumulated charge is measured by the charge measuring means 31 for its integrated value. Based on the measured charge amount, the data processor 32 performs arithmetic processing using the conversion constant from the charge amount to the radiation dose determined in advance, and measures the radiation dose.

  According to the present embodiment, since ions ionized by the radiation of the measurement object 1 are measured as an accumulated charge amount, even if the generated ions are weak ions, it can be measured with high sensitivity, and highly accurate radiation measurement can be performed.

Next, a fifth embodiment of the present invention will be described with reference to FIG.
In FIG. 5, 33 is an insulated conductor installed in the gas circulation path 8 between the gas converging device 14 and the ion collector 9, and 34 is a charging device for charging the conductor 33 positively or negatively. , 35 is input with the ionization current value measured by the ionization current measuring device 6, and the ionization current value measured when the conductor 33 is positively charged and the ionization current value measured when the conductor 33 is negatively charged. Data analysis means for correcting the radiation dose based on the relationship with the value.

  In the radiation measuring apparatus according to the present embodiment, first, when the conductor 33 is positively charged by the charging means 34 and the gas 5 in the measurement chamber 2 is circulated in the gas circulation path 8, the minus in the gas 5 is obtained. Ions are adsorbed on the conductor 33, and only positive ions pass through and are collected by the ion collector 9 and measured by the ionization current measuring device 6 as the first current value.

Next, when the electric conductor 33 is negatively charged by the charging device 34 and the gas 5 in the measurement chamber 2 is circulated in the gas circulation path 8, the positive ions in the gas 5 are adsorbed by the electric conductor 33 and become negative ions. Only passes and is collected by the ion collector 9 and measured by the ionization current measuring device 6 as the second current value.
Here, the ions of the measuring object 1 are considered to be cluster ions including a plurality of water molecules, and plus and minus having different components.

Therefore, the relationship between the ratio of the current value due to positive ions and negative ions, which changes according to the amount of moisture in the gas determined in advance, and the rate of change in current intensity due to negative ions, and the negative ions and positive ions measured as described above. The rate of change of current intensity is calculated from the ratio of current values obtained by, and the measured current value is corrected with the rate of change of current intensity. Using the corrected current value and the conversion constant from current to radiation dose, the data The radiation amount is obtained by arithmetic processing by the analyzing means 13.
According to the present embodiment, since the radiation dose is obtained by correcting the moisture content in the gas, highly accurate radiation measurement can be performed.

Next, a sixth embodiment of the present invention will be described with reference to FIG.
In FIG. 6, reference numeral 36 denotes a particle collecting device attached to the gas inlet side of the measurement chamber 2 in place of the gas diffusion device shown in FIG. 1, and a gas intake for taking the atmosphere into the measurement chamber 2 at the center thereof. A mouth 37 is formed.

On the other hand, the outlet of the particle collecting device 10 provided in the gas circulation path 8 is discharged into the atmosphere without being circulated back to the measurement chamber 2.
In the radiation measuring apparatus according to the present embodiment, outside air is taken into the measurement chamber 2 through the gas inlet 37, and at this time, the aerosol in the outside air is collected by the particle collecting means 36.

The gas introduced into the measurement chamber 2 is ionized in the same manner as described in the first embodiment shown in FIG. 1, and the high-speed gas generated by the gas blowing means 19 is converted into a plurality of gas ejection devices 17. The nozzle tip is sprayed onto the measuring object 1 and the ions generated on the surface of the measuring object 1 are peeled off, and the ionization current is measured.
The gas after collecting the ions is purified through the particle collecting device 10 and released into the outside air.

  According to the present embodiment, the gas after collecting the ions is purified through the particle collecting device 10 without being returned to the measurement chamber 2 and released into the outside air, so that the gas return path is omitted. In addition to simplifying and downsizing the measurement apparatus, the sensitivity position dependency on the measurement object 1 is reduced, and highly accurate radiation measurement can be performed.

Next, a seventh embodiment of the present invention will be described with reference to FIG.
In FIG. 7, 38 is a storage container for storing a plurality of reactor fuel rods 39, which are radiation measurement objects, and 17 is attached to the wall of the measurement chamber 2 along the axial direction of the reactor fuel rods. A plurality of gas ejection devices.

  In the radiation measuring apparatus according to the present embodiment, gas is ejected from a plurality of gas ejection devices 17 attached in the axial direction of the nuclear reactor fuel rod 39 and generated near the surface of the nuclear reactor fuel rod 39. The separated ions are peeled off and efficiently transferred to the gas circulation path 8 leading to the ion collector 9. Therefore, the difference in sensitivity in the axial direction of the nuclear reactor fuel rod 39 is reduced, and high-precision radiation measurement can be performed.

Here, the radiation dose measuring device for the nuclear reactor fuel rod 39 is extremely sensitive to α radiation having a remarkably large generation density of ionized ions in the gas. In contrast, it can be used for contamination inspection of nuclides that emit alpha rays.
Further, in addition to the nuclear reactor fuel rod 39, the reactor fuel assembly and the radioactive contamination can be used for the surface contamination inspection of the container containing the solidified treatment.

Next, an eighth embodiment of the present invention will be described with reference to FIG.
In FIG. 8, reference numeral 40 denotes a measurement target space as a measurement target, and a plurality of gas ejection devices 17 that inject gas into the measurement target space 40 are attached to the wall of the measurement chamber 2.

In the radiation measuring apparatus according to the present embodiment, the high-speed gas is supplied from the plurality of gas ejection devices 17 into the measurement target space 40 in the measurement chamber 2 without being limited to a solid having a shape as the measurement target. The gas 5 in the measurement target space 40 is ejected and transferred to the gas circulation path 8 without stagnating, and radiation measurement is performed.
Therefore, the measurement object referred to in the present invention includes the measurement object space.
The gas after passing through the ion collector 9 is purified by the particle collecting means 36 and released to the outside air.

  According to the present embodiment, since ionized ions in the measurement target space are transferred and measured, it is possible to reduce the residual ions and reduce the sensitivity difference due to the spatial position even for the measurement target 1 in a wide space. Highly accurate radiation measurement can be performed.

The block block diagram of the radiation measuring device by the 1st Embodiment of this invention. The block block diagram of the radiation measuring device by the 2nd Embodiment of this invention. The block block diagram of the radiation measuring device by the 3rd Embodiment of this invention. The block block diagram of the radiation measuring device by the 4th Embodiment of this invention. The block block diagram of the radiation measuring device by the 5th Embodiment of this invention. The block block diagram of the radiation measuring device by the 6th Embodiment of this invention. The block block diagram of the radiation measuring device by the 7th Embodiment of this invention. The block block diagram of the radiation measuring device by the 8th Embodiment of this invention. The block block diagram which shows the conventional radiation measuring device. The block block diagram which shows another conventional radiation measuring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Radiation measuring object, 2 ... Measurement chamber, 3 ... Suction device, 5 ... Gas, 6 ... Ionization current measuring device, 7, 32, 35 ... Data processing device, 8 ... Gas circulation path, 9 ... Ion collector DESCRIPTION OF SYMBOLS 10, 25, 36 ... Particle collection device, 12 ... Gas blower, 13 ... Voltage application device, 14 ... Gas converging device, 15 ... Gas diffusion device, 16 ... Air blower, 17 ... Gas ejection device, 18 ... Air blow Pipe 19, Gas blower 20, Opening / closing device 21, Opening / closing control device 22, Rotating device 23, Rotating angle detection device 24, Rectifying plate 26, Shooting device 27, First particle collecting device 28 ... second particle collecting device, 29 ... charge collecting device, 30, 33 ... conductor, 31 ... charge measuring device, 34 ... charging device, 37 ... gas inlet, 39 ... reactor fuel rod, 40 ... measurement target space.

Claims (12)

  A measurement chamber for storing a measurement object of radiation together with a gas, a gas circulation path for circulating a gas in the measurement chamber containing ionized ions ionized by radiation of the measurement object, and ions provided in the gas circulation path Data that computes the radiation dose of the measurement object based on the ionization current measured by the collection device, the ionization current measurement device that measures the ionization current from the ions collected by the ion collection device, and the ionization current measurement device A processing device, a plurality of gas ejection devices that are provided so as to surround the measurement object stored in the measurement chamber from the periphery thereof, and a gas blower that sends gas to the gas ejection device A radiation measuring apparatus comprising:   The first particle collection device provided on the gas outlet side of the measurement chamber and the downstream side of the gas flow of the ion collection device, and smaller than the collection target particle size of the first particle collection device The radiation measuring apparatus according to claim 1, further comprising a second particle collecting device having a particle size to be collected.   Provided in a gas circulation path between the gas outlet side of the measurement chamber and the ion collector, a conductor insulated from the gas circulation path, and a charging device for charging the conductor positively and negatively. The radiation dose is corrected based on the ionization current value measured when the conductor is positively charged and the ionization current value measured when the conductor is negatively charged. The radiation measuring apparatus according to claim 1.   A measurement chamber for storing a measurement object of radiation together with gas, a gas circulation path for circulating gas in the measurement chamber containing ionized ions ionized by radiation of the measurement object, and charge collection provided in the gas circulation path Device, charge measuring device for measuring the charge amount from the accumulated charge amount collected by the charge collecting device, and data processing device for calculating and processing the radiation dose of the measurement object based on the charge measured by the charge measuring device And a plurality of gas ejection devices that are provided so as to surround the measurement object stored in the measurement chamber from the periphery thereof, and a gas blower that sends gas to the gas ejection device. A radiation measuring device.   The radiation measuring apparatus according to claim 1, wherein the position of the gas ejection device can be freely changed with respect to the measurement object.   An opening / closing device provided between the plurality of gas ejection devices and the gas blowing device, and having an opening / closing valve for controlling the opening / closing of the amount of air sent to each gas ejection device, and controlling the opening / closing of the opening / closing valve of the opening / closing device. The radiation measuring apparatus according to claim 1, further comprising an opening / closing control device that performs the operation.   A rotation device that rotates the measurement object; and a rotation angle detection device that detects a rotation angle of the measurement object, and controls opening and closing of the opening and closing valve of the opening and closing device according to the rotation angle of the measurement object. The radiation measuring apparatus according to claim 6, wherein   The ionization current or charge is measured when gas is ejected from the gas ejection device into the measurement chamber, and the radiation dose is obtained based on the measured ionization current or charge value. The radiation measuring apparatus according to item 2.   The radiation measuring apparatus according to claim 7, wherein an imaging apparatus that captures an image of the measurement object is provided, and a rotation angle of the measurement object is detected from an image signal of the imaging apparatus.   A first particle collecting device which is attached to the gas inlet side of the measurement chamber and forms a gas intake port for taking the atmosphere into the measurement chamber, and after measuring the ionization current of the gas flowing through the gas circulation path, The radiation measuring apparatus according to claim 1, further comprising: a second particle collecting device that is released into the inside.   The radiation measurement apparatus according to claim 1, wherein the measurement object is a nuclear fuel rod. The radiation measurement apparatus according to claim 1, wherein the measurement object is a measurement object space.

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