JP2015102480A - Radiation leakage inspection method and inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection method and an inspection device capable of achieving secure measurement without measurement omission and simplification of measurement workability by measuring radiation leakage with a plane system.SOLUTION: The whole area of a measurement object surface can be measured without measurement omission with a plane system by measuring a radiation while moving a radiation meter group in which radiation meters are arranged in a row along a wall surface, a floor surface and a ceiling surface being measurement object surfaces. Therefore, a secure inspection without inspection omission can be performed within a range of the inspected area. The method is a plane inspection system which does not require setting of a device for each measurement point, achieves simplification in a measurement work as much as possible, significantly shortens inspection time, and significantly reduces a burden on an operator. Further, the method can perform inspection in the middle of a construction work and facilitate a repair work.

Description

  The present invention relates to an inspection method and an inspection apparatus for inspecting leakage of radiation from a room having a radiation source such as X-ray inspection or treatment using a radioisotope in a medical institution such as a hospital by a surface scanning method. It is about.

In medical institutions such as hospitals, examinations and treatments using radiation are performed. For example, in order to examine the state of the internal organs, the doctor makes a comprehensive decision with reference to X-ray images of the chest and abdomen taken in the X-ray room, blood test results, urinalysis results, etc. in addition to palpation and interviews. doing. In one hospital, the number of X-ray images taken is several tens to several hundreds per day, and it is enormous in a large university hospital or general hospital.
On the other hand, the X-ray room is surrounded by a corridor, other examination rooms, and waiting rooms, and the upper and lower floors are corridors, hospital rooms, and examination rooms. Therefore, it is very important to take measures to prevent leakage so that radiation does not leak from the X-ray room.
As a countermeasure for preventing radiation leakage, it is common to apply a lead plate. By interposing a lead plate, radiation is blocked so that the radiation does not penetrate from the X-ray room to the surrounding corridor or hospital room.

  However, when constructing X-ray rooms, door work for entry and exit, electrical wiring, lighting switches and outlet box equipment work are required, and various pipe work such as water pipes, air conditioning pipes, and sanitary pipes are also required. It is. In order to perform these facilities work and piping work, an opening must be formed in the wall surface. Each of these openings is individually laid with lead plates for radiation leakage. However, radiation leakage occurs due to artificial factors such as skill differences among craftsmen and construction errors.

  Therefore, when construction work is once completed, radiation leak inspection is performed using a survey meter. The inspection method is described in detail in Patent Document 1. Patent Document 1 is a “Manual for X-ray Treatment Room Leakage Dose Measurement” issued in March 2013 by the Japan Medical Imaging System Association.

According to the description in Patent Document 1, a partition wall outside the management area boundary is measured at an appropriate interval. A measuring instrument (ionization chamber type survey meter or the like) has a height of 1 m from the floor, and measures it perpendicularly to the outer surface of the partition wall. Furthermore, the location closest to the radiation source, the partition on the side of the utility line, the surroundings of the protective door and the summing part, the mounting part of the observation window, the cable pit, the ventilation fan, and other openings are carefully measured.

  In addition, in the appendix drawing of Patent Document 1, specific measurement points outside the boundary of the management area of many X-ray rooms are represented by circled numbers. According to this appendix drawing, the conventional radiation leakage inspection performs spot measurement at 20 to 30 selected locations on the front, back, left, right, and upper and lower wall surfaces of the X-ray room.

X-ray treatment room management area leakage dose measurement manual (Japan Society for Medical Imaging Systems, issued in March 2013)

As mentioned above, the X-ray room has an opening on the wall surface for door work for entry and exit, electrical wiring, equipment work for lighting switches and outlet boxes, and plumbing work such as water piping, air conditioning piping, and sanitary piping. Therefore, if the radiation leakage prevention measures for these openings are insufficient, radiation will leak from these openings.
Leakage prevention measures have become inadequate due to craftsmanship differences and man-made factors such as construction mistakes, so it was inevitable that radiation leakage would occur.

  In this way, radiation that leaks from the X-ray room management area in a spot manner using a survey meter, as shown in Patent Document 1, despite the occurrence of a radiation leakage accident due to human factors. However, this method has a fatal disadvantage that it cannot be detected even if radiation leaks in a region outside the measurement point.

  In addition, the spot measurement method has a drawback in that measurement cannot be performed continuously, and it is necessary to install a survey meter as a measuring instrument at each measurement point, and the measurement work is complicated.

  Furthermore, the conventional radiation leakage inspection has been performed after completion of facility construction and building construction after the installation of the radiation source. Therefore, when there is radiation leakage, it takes twice the work of tearing the boundary wall of the management area and applying leakage prevention processing without any gaps, and then rebuilding the wall, extending the work period and increasing costs. There was a drawback.

The present invention is an improvement and removal in view of the above-mentioned conventional problems. By measuring radiation leakage by a surface method, it is possible to realize reliable measurement without measurement leakage and simplify measurement workability. An inspection method and an inspection apparatus that can be realized are provided.

The means of claim 1 adopted by the present invention in order to solve the above problem is to move a group of radiation measuring instruments in which radiation measuring instruments are arranged in a line along a wall surface, a floor surface, or a ceiling surface as a measurement target surface. In this radiation leakage inspection method, the entire measurement target surface is measured without measurement omission by measuring radiation.

According to the second aspect of the present invention, when the measurement target surface is larger than the longitudinal dimension of the radiation group, the total length of the measurement target surface is measured at the first time, and the remaining unmeasured measurement target at the second time. This is a radiation leakage inspection method in which the entire surface of the measurement target surface is measured without measurement omission by measuring the surface while moving the radiation measuring instrument group.

According to a third aspect of the present invention, there is provided a radiation leakage inspection apparatus including a radiation measuring instrument group in which radiation measuring instruments are arranged in a row at predetermined intervals, and a case main body that houses the radiation measuring instrument group.

The means according to claim 4 employed by the present invention is the radiation leakage inspection apparatus according to claim 3, wherein the number of radiation measuring instrument groups is two or more and not more than ten and is portable.

  According to the fifth aspect of the present invention, the case main body is mounted across the slide rails arranged on both sides in the longitudinal direction of the radiation measuring instrument group, and the case main body is arranged in the longitudinal direction of the radiation measuring instrument group. The radiation leakage inspection apparatus according to claim 3, wherein the radiation leakage inspection apparatus is configured to be slidable to adjust the position.

The means of claim 6 employed by the present invention is the radiation leakage according to claim 5, wherein the slide rails on both sides constitute an outer casing, and wheels are attached to a lower end surface and a front end surface of the outer casing. Inspection equipment.

  In the first aspect of the invention, for example, the entire surface of the wall surface can be measured by a surface method by measuring the radiation dose while moving the radiation measuring instrument groups arranged in a vertical row. When the radiation measuring instrument group is arranged at predetermined intervals over the entire length in the height direction of the wall surface, the entire surface of the wall surface can be measured with a single lateral movement without measurement omission.

  In the invention of claim 2, when the radiation measuring instrument group reaches, for example, only halfway in the height direction of the wall surface, the surface from the floor surface to the height dimension of the radiation measuring instrument group is first traversed. Move and measure. Subsequently, it is possible to measure the radiation leakage of all the wall surfaces by arranging the radiation measuring instrument groups corresponding to the remaining wall surfaces and moving them in that state.

  The invention of claim 3 is an apparatus invention for carrying out the method invention of claim 1.

  The invention of claim 4 is a portable (handy type) apparatus, and is suitable for inspecting radiation leakage of a measurement target surface having a small area. It is possible to inspect the radiation leakage by a surface method by moving the operator up and down or left and right while holding it by hand, and it is possible to measure the entire measurement target surface very easily and reliably.

The invention of claim 5 is an apparatus invention for carrying out the method invention of claim 2, and the radiation measuring instrument group is slidable in the longitudinal direction. Therefore, it is possible to easily cope with the measurement of the second remaining wall surface after the first measurement of the radiation dose.

  The invention of claim 6 embodies the moving means in the invention of claim 5, and a wheel is attached to at least the lower end surface of the outer casing. Further, when there is a radiation source room below the floor, it is necessary to move the radiation measuring instrument group downward, and a wheel is attached to the front end surface of the outer casing via a support leg and moved.

BRIEF DESCRIPTION OF THE DRAWINGS The inspection apparatus which concerns on one embodiment of this invention is shown, A figure (A) is a front view, A figure (B) is a side view. It is a drawing. It is a longitudinal cross-sectional view which shows simultaneously the state which is test | inspecting the wall surface and the ceiling of a downstairs with the inspection apparatus which concerns on one embodiment of this invention.

  FIG. 1A and FIG. 1B of the configuration of the present invention show a radiation leakage inspection apparatus 1 according to an embodiment of the present invention, and FIG. FIG. (B) is a left side view. As shown in the figure, the inspection apparatus 1 is provided with a number of survey meters 3 of ionization chamber type or the like on the front side of a casing 2 constituting the apparatus main body. The survey meter 3 may be arranged at intervals of 10 cm in a commercially available general product depending on its detection capability. Accordingly, the number of installations in a row is about 20 if the normal indoor height is 2 m, and about 25 if the height is 2.5 m. This can be set arbitrarily.

  The housing 2 in which the survey meter 3 is installed is externally fitted to the outer casing 4. The outer casing 4 has slide rails facing the left and right side surfaces of the housing 2, and the housing 2 is slidable in the vertical direction with respect to the outer casing 4. And it can fix by the method etc. which insert a pin from the outer side of the outer casing 4 to the pin hole (not shown) provided in the outer casing 4 and the housing | casing 2 in arbitrary sliding height positions.

Further, on the lower end surface of the outer casing 4, movable wheels 5 are attached at least at four locations, front, rear, left and right. A part of the wheel 5 is disposed on the inner side of the outer casing 4 so that the height dimension of the survey meter 3 located at the bottom from the floor surface does not exceed 10 cm.
Further, on the front end surface of the outer casing 4, support legs 6 are attached so as to protrude in four places on the upper, lower, left and right sides, and wheels 7 are attached to the front end side of the support legs 6 so as to be able to roll.

Next, the operation | movement aspect of the radiation leakage inspection apparatus 1 comprised in this way is demonstrated. First, the leakage inspection is performed immediately after installing a member that blocks radiation, such as a lead plate, on the boundary surface of the management area of the radiation room. In other words, after the lead plate is attached to the boundary surface of the radiation control area, it is performed in the middle of the construction work before finishing the wall surface on the outside. This is because even if there is a radiation leaking portion, the repair work for attaching the lead plate to the leaking portion can be easily performed without turning the wall surface.
As shown in FIG. 2, the leakage inspection is performed by installing an apparatus 8 capable of continuously generating X-rays in the radiation chamber A.

  When performing leakage inspection on the wall surface of the radiation chamber A, with the continuous X-ray generator 8 in the radiation chamber A operated, first, as shown on the left wall surface L in FIG. Deploy. The inspection device 1 faces the survey meter 3 so as to be orthogonal to the wall surface L, and is arranged close to the wall surface L so as not to be too far away, and starts from one end of the wall surface L. . In the leak inspection, the inspection apparatus 1 may be moved sequentially along the wall surface L and moved to the other end of the wall surface L. The group of survey meters 3 arranged in a line is arranged at a predetermined interval so that each survey meter 3 can perform a leak-free inspection according to its measuring ability.

Therefore, only by moving the inspection device 1 from one side of the wall surface L to the other side, the height of the wall surface L from the floor surface to the measurable area of the survey meter 3 positioned at the highest position of the inspection device 1 is increased. The entire surface can be inspected for radiation leakage at once.

When the height dimension of the wall surface is higher than the height dimension of the survey meter 3 group of the inspection apparatus 1, first, the surface type radiation leakage inspection from the floor surface to a predetermined height dimension in the same manner as the inspection of the wall surface L. I do. After that, as shown in the right wall surface R of FIG. 2, the casing 2 of the inspection device 1 is slid so that the measurable range of the survey meter 3 group reaches the ceiling. What is necessary is just to carry out a radiation leakage inspection continuously while moving from one side to the other side. Even in the second inspection, on an extremely high wall surface or floor surface where an uninspected region is formed, the inspection may be performed a plurality of times such as three times or four times.
In the inspection performed after the second time, there may be a case where a region to be inspected is overlapped with the case of the last time. Therefore, each survey meter 3 may be individually turned on and off, and the survey meter 3 in the overlapping portion may be turned off to perform the last and subsequent measurements.

  As described above, the inspection apparatus 1 according to the present embodiment performs the radiation leakage inspection by the surface method by moving the group of survey meters 3 arranged in a column in the horizontal direction, so that there is surely no inspection leakage within the range of the inspected area. Inspection is possible. In addition, since the inspection device 1 can be simply moved, it is not necessary to set the device for each measurement point, the measurement work is greatly simplified, the inspection time is greatly shortened, and the burden on the worker is greatly reduced. It is possible. Furthermore, measurement is possible during the construction work when the lead plate laying work is completed, so even if there is a defective part of the lead plate laying work, there is no need to remove the wall surface and perform repair work. Can be easily dealt with.

  As shown in FIG. 2, in the case of the second floor portion of the radiation chamber A, the measurement may be performed in a state where the survey meter 3 group of the inspection apparatus 1 is tilted down. In that case, it is convenient if the apparatus main body 1 is moved laterally by using the support legs 6 and the wheels 7 attached to the front end surface of the outer casing 4.

  Furthermore, as another embodiment, there is a case of a portable (handy type) radiation leakage inspection. In this portable type, although depending on the weight and size of the survey meter, a plurality of survey meters of 2 to 10 that can be carried by a measurement worker alone are arranged in a line. In use, while holding a portable radiation leakage inspection apparatus by hand, this is moved in the vertical direction or the horizontal direction, etc., and the leakage of radiation is inspected by a surface method. As long as the measurement target surface has a narrow area, even this portable type can be reliably inspected by the surface scanning method without omission of measurement.

By the way, this invention is not limited to embodiment mentioned above, A suitable change is possible. For example, the outer casing may be eliminated, and the housing 2 in which the survey meters 3 are arranged in a row may be placed on a cart (not shown) with a low height and measured while moving. Further, the housing 2 of the survey meter 3 group may be placed on a high cart, and a wall surface in a range from the ceiling to a predetermined dimension may be inspected.
Furthermore, the radiation leak inspection was explained after the lead plate was installed and during the construction work, but after the construction work was completed, it should be carried out immediately before the delivery. It is also possible to make it.

DESCRIPTION OF SYMBOLS 1 ... Radiation leakage inspection apparatus 2 ... Case 3 ... Survey meter 4 ... Outer casing 5 ... Wheel 6 ... Support leg 7 ... Wheel 8 ... Continuous X-ray generator

Claims (6)

By measuring radiation while moving a group of radiation measuring instruments in a line along the wall, floor, or ceiling that is the surface to be measured, the entire surface of the surface to be measured is measured without omissions. Radiation leakage inspection method. If the measurement target surface is larger than the longitudinal dimension of the radiation group, measure the total length of the measurement target surface at the first time, and measure the remaining unmeasured measurement surface while moving the radiation measuring instrument group at the second time. A radiation leakage inspection method that measures the entire measurement target surface without measurement omission. A radiation leakage inspection apparatus comprising a radiation measuring instrument group in which radiation measuring instruments are arranged in a row at predetermined intervals, and a case main body that houses the radiation measuring instrument group. The radiation leakage inspection apparatus according to claim 3, wherein the number of radiation measuring instrument groups is two or more and not more than ten and is portable. The case body is mounted across the slide rails arranged on both sides of the radiation measuring instrument group in the longitudinal direction, and the case body is configured to slide in the longitudinal direction of the radiation measuring instrument group to adjust the position. The radiation leakage inspection apparatus according to claim 3. The radiation leakage inspection apparatus according to claim 5, wherein the slide rails on both sides constitute an outer casing, and wheels are attached to a lower end surface and a front end surface of the outer casing.

Images