JPH0442083A - Radiation measuring apparatus - Google Patents

Abstract

PURPOSE:To easily mount by burying a plurality of radiation detecting elements in a flexible insulation film to be mounted on an object to be measured, and connecting it to the film through a wiring formed in the film. CONSTITUTION:A film 10 is wound over the entire periphery of the surface of a tube. Thus, a radioactive ray radiated from the content of the tube in which the film 10 is mounted is detected by many semiconductor radiation detecting elements 11 buried in the film 10. When the rays are detected, radiation detection pulses are output, and inputs to an amplifier 12 through a capacitor C. An electric signal in which noise component is cut OFF by the capacitor C to be amplified by the amplifier 12 is output to a pulse counter 14. The counter calculates a pulse counting rate together with the radiation detection signal sent from other channel, and measures a radiation dose.

Description

Detailed Description of the Invention [Purpose of the Invention [Industrial Field of Application] The present invention relates to a radiation detector that is attached to piping, etc. in a nuclear facility, etc., and measures the amount of radiation emitted from the contents or the piping itself. Concerning a measuring device.

[Conventional technology]

In nuclear facilities and the like, radiation levels contained in gases and liquids passing through process piping installed within the facility are measured by radiation measurement devices attached to the process piping.

In this type of conventional radiation measuring device, for example, as shown in FIG. 145, a radiation detector 2 having a built-in radiation detecting element inside a container is fixed by a band 3 in close contact with the outer surface of a process pipe 1. .

Then, the radiation emitted from the contents of the process pipe 1 is detected by the radiation detector 2, and the radiation detection signal is sent to the pulse counting circuit 4, where the radiation dose is measured. Note that 5 shown in the figure is a radiation shield made of lead or the like, and the entire process piping 1 is covered by this shield 5.

Furthermore, as another conventional example, as shown in FIG. 6, a well has been considered on the outside of the process piping 1, into which the radiation detector 2 is inserted.

However, when measuring radiation by attaching the radiation detector 2 externally to the surface of the process piping 1 as described above, if the diameter of the piping is large, the radiation detector 2 may be attached to the surface of the process piping 1, and if the diameter of the piping is large, the contents may be The emitted radiation is detected by radiation detector 2
This has the disadvantage that sufficient detection sensitivity may not be obtained. In addition, when installing a box-shaped radiation detector externally as shown in Figure 5, there are restrictions on the installation location of the radiation detector 2, and when installing it on a curved surface such as piping, the installation is complicated. accompanied by.

Therefore, as shown in FIG. 7, a radiation measuring device is designed to improve radiation detection efficiency by protruding a well 6 into the process pipe 1 and inserting the radiation detector 2 into the well 6 to bring it close to the contents. is considered.

However, the structure shown in FIG. 7 has a drawback that the well 6 obstructs the flow path on the process side.

[Problem to be solved by the invention]

Therefore, when installing a conventional radiation measuring device on an object to be measured with a curved surface such as a pipe, the installation is laborious and complicated, and there are restrictions on the installation location of the radiation detector. There was a problem in that sufficient radiation detection efficiency could not be obtained, and if the well 6 was structured to protrude into the process piping 1 in order to obtain sufficient radiation detection efficiency, smooth transfer of the contents would be inhibited.

The present invention was made in view of the above-mentioned circumstances, and it is easy to install even a measurement object having a curved surface such as a pipe, and there is no need to insert a radiation detector into the flow path inside the pipe. It is an object of the present invention to provide a radiation 11 detection device that can obtain sufficient radiation detection efficiency even when the radiation detection efficiency is high.

C. Constitution of the Invention [Means for Solving the Problems] In order to solve the above problems, the present invention has a plurality of radiation detection elements embedded in a flexible insulating film attached to an object to be measured. The detection element was configured to be connected to the outside of the film via wiring formed in the film.

[Effect]

By taking the above-mentioned measures, the present invention allows a film in which a plurality of radiation detection elements are embedded to be easily wrapped around the outer periphery of an object to be measured, even if the object has a curved surface, such as a pipe. It is possible to obtain radiation detection efficiency equivalent to that obtained when a radiation detector is inserted in the center of the pipe.

〔Example〕

Examples of the present invention will be described below.

The radiation measuring device according to this embodiment is composed of a radiation detection system attached to an object to be measured such as a pipe, and a measurement circuit system that measures the radiation dose from the output of this radiation detection system.

FIG. 1 is a diagram showing the configuration of the radiation detection system. Reference numeral 10 shown in the figure is a flexible film made of polyimide, for example. In this film 10, there are a plurality of semiconductor detection elements 11 arranged in a matrix, a plurality of amplifiers 12 for amplifying the output of each semiconductor detection element 11, and a plurality of semiconductor detection elements 11 for each line connected and an amplifier. A conductive line 13 is built in to guide the output of 12 to the outside of the film. Note that the semiconductor detection element 11 used has extremely low sensitivity to γ-rays and high sensitivity to β-rays.

FIG. 2 shows a part of the circuit configuration within the film 10 and the configuration of the measurement circuit system. One end of the semiconductor detection element 11 is grounded, and the other end is connected to the power supply side via resistive elements rl and r2 connected in series. An input terminal of an amplifier 12 is connected via a capacitor C between resistive elements r1 and r2.

The output terminal of the amplifier 12 is connected to an external connector terminal 14 of the film 10. A pulse counting circuit 14 is connected to the external connector terminal 14 of the film 10. A pulsed radiation detection signal from the radiation detection element 11 is manually input to this pulse counting circuit 14, and a pulse count rate calculation is performed by a microcomputer or the like. The calculation results by the pulse counting circuit 14 are sent to a radioactivity display 15 and a remote display 16 in the monitoring room.

3 and 4 are diagrams showing the state in which the film 10 is attached to the pipe 1, and FIG. 3 is a sectional view taken in a direction perpendicular to the pipe axis, and FIG. 4 is a side view. There is. In this embodiment, two rectangular films 10a,'
The film 10b covers the entire circumference of the pipe 1, and is fixed to the pipe 1 by screwing both ends of the two films 10a and 10b. In addition, 17 shown in the same figure is a protective case, and the film 10 which becomes a radiation detector is wound from above this protective case 17.

Next, the operation of this embodiment will be explained.

A film 10 is wrapped around the entire surface of the pipe 1. Note that when the diameter of the pipe 1 is large, two films 10a and 10b are used as described above. Radiation emitted from the contents of the pipe 1 to which the film 10 is attached in this manner is detected by a large number of semiconductor radiation detection elements 11 embedded within the film 10. When radiation is detected, a radiation detection pulse is output and input to the amplifier 12 via the capacitor C. Noise components are cut by capacitor C. The radiation detection pulse is amplified into an electrical signal (radiation detection signal) of sufficient magnitude by the amplifier 12 and output to the pulse counting circuit 14 . In the pulse counting circuit 14, pulse counting rate calculation is executed together with radiation detection signals sent from other channels to measure the radiation dose. The radiation measurement results are sent to a radioactivity display 15 and a remote display 16, respectively.

Radiation measurement of the contents transferred within the pipe 1 is performed as described above.

As described above, according to this embodiment, the flexible film 1
Semiconductor detection element 11. Amplifier 12° Conductive line 13
Since the detector part (film 10) was buried in the pipe 1
Since it can be easily attached to the outer surface of the pipe 10 and can cover the entire circumference of the pipe 10, it is possible to obtain radiation detection efficiency equivalent to that of the pipe 1 without inserting a detector into the flow path inside the pipe 1. can.

In addition, compared to detectors housed in containers, there are no restrictions on the installation location, and there is no need to provide special wells, etc., making it easy to install and install on piping. Work is simplified.

Furthermore, since the semiconductor detection element 11 is used, which has extremely low sensitivity to gamma rays and high sensitivity to β rays, a background shielding effect can be obtained, and measurement accuracy can be improved.

Furthermore, by adjusting the shielding effect of the protective case 17 and the thickness of the pipe 1 itself to shield radiation from the contents, it is also possible to measure the radioactivity on the surface of the pipe.

In the above embodiments, pipes and their contents were used as objects to be measured, but the present invention can be applied to drum pipes filled with radioactive materials and other similar objects with curved parts. Effects can be obtained.

[Effects of the Invention] As described in detail above, the present invention is suitable for radiation measurement of objects having curved surfaces such as piping, allows for a simple and compact configuration, and provides sufficient radiation detection efficiency. It is possible to provide a radiation measurement device that can perform

[Brief explanation of the drawing]

Figure 1 is a plan view of a film-shaped detector in which semiconductor detection elements are embedded, Figure 2 is a diagram showing part of the circuit configuration inside the film and the configuration of the measurement circuit system, and Figure 3 is a plan view of a film-shaped detector in which a semiconductor detection element etc. is embedded. Figure 4 is a cross-sectional view of the pipe with the detector attached, Figure 4 is a side view of the pipe, Figure 5 is a diagram showing the box-shaped radiation detector attached to the surface of the pipe, Figure 6 is radiation detection. A cross-sectional view of a pipe in which a well into which a vessel is inserted protrudes outward;
FIG. 7 is a sectional view of a pipe in which a well is provided on the flow path side. 10... Film, 11... Semiconductor detection element, 12
... Amplifier, 13... Conductive line, 14... Pulse counting circuit, 15... Radiation indicator, 16... Remote indicator, 17... Protective case. Applicant's Representative Patent Attorney Takehiko Suzue Chest Diagram

Claims (1)

[Claims] A radiation measuring device that is attached to an object to be measured and measures the amount of radiation emitted from the object, comprising: a plurality of radiation detection elements embedded in a flexible insulating film; A radiation measuring device characterized in that each radiation detection element is connected to the outside of the film via wiring formed in the film, and the film is attached to the object to be measured.