KR20180050016A - Total inspection system and method for measuring the alpha, beta, and gamma radioactivity from dismantled radioactive wastes in the nuclear power plant decommissioning - Google Patents

Abstract

The present invention relates to a system and a method for automatically inspecting radioactive contamination, capable of continuously inspecting the radioactive contamination on a surface of a radioactive wastes regardless of the type and size of the radioactive wastes in order to inspect whether dismantled radioactive wastes of a nuclear plant exceed a limitation of radioactive tolerance. The inspection system includes: a radioactive shielding compartment that can be moved by a transport unit to be used at a nuclear dismantling site; a conveyor installed in the radioactive shielding compartment to supply or discharge inspection objects loaded on an inspection tray; a shielding portion completely shielded by the radioactive shielding compartment and preventing an influence of an external electromagnetic line when measuring a radioactivity of the inspection object transferred by the conveyor; a distance measuring unit disposed inside the shielding portion to measure a height and a size of the inspection object; a radioactive measuring unit arranged to be movable up and down inside the shielding portion to perform a radioactive test on the inspection object, and to perform alpha, beta and gamma radioactive measurements at a height calculated based on data measured by the distance measuring unit; a radioactive analyzer for analyzing the radioactivity measured by the radioactive measuring unit; and a control unit that sequentially performs the radioactivity test by interworking with the conveyor, the shielding portion, the distance and weight measuring unit, the radioactivity measuring unit and the radioactive analyzer.

Description

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a radiation inspection system and method for nuclear dismantling waste that emits alpha, beta and gamma rays,

[0001] The present invention relates to a method and system for continuously inspecting radioactivity from wastes generated during disintegration of nuclear power plants, and more particularly to a method and system for continuously inspecting radioactivity from waste generated during disintegration of nuclear power plants by transferring nuclear waste such as concrete, The present invention relates to a system and method for continuously measuring alpha, beta and gamma rays generated in a waste while being transported by means.

Generally, in the case of decommissioning old nuclear power plants, large amounts and kinds of nuclear dismantled waste come out, and the most of concrete structures, metals, vinyls and fibers contaminated with radioactivity are occupied. Some of these radioactive wastes are permanently disposed of because they are not capable of radioactive decontamination, but many are recycled through appropriate decontamination activities.

However, in order to recycle the dismantled waste generated at the dismantling of the nuclear power plant, the radioactivity from the waste should be below the self disposal level set by the relevant laws and regulations. do.

The various types of radioactive waste generated at the dismantling of nuclear power plants emit alpha rays, beta rays, or gamma rays. Depending on the nature of the radionuclides and the type of radiation, these radioactive wastes are self-disposed radioactive Concentration is determined by the Nuclear Safety Act.

Radioactive Nucleus Radionuclide Allowable concentration
(Bq / g) I-129 0.01 Sb-125, Cs-134, Cs-137, Eu-22, Sc-46, Mn-54, Co-56, Co-60, Zn-65, Nb- 152, Eu-154, Ta-182, Bi-207, Th-229, U-232, Pu-238, Pu-239, Pu-240, Pu-242, Pu- 0.1 C-14, Na-24, Cl-36, Sc-48, g-105, Cd-109, Sn-113, Sb-124, Te-123m, Te- 140, Ce-139, Eu-155, Tb-160, Hf-181, Os-185, Ir-190, Ir-192, Tl-204, Bi-206, U-233, Np-237, One Co-55, Ni-65, Ga-72, Nb-98, I-130, I- 131, I-132, I-133, I-134, I-135, Cs-129, Cs-132, Cs-138, Ba- Ra-225, U-230b, U-236, Np-240, u-241, etc. 10 H-3, S-35, K-42, Ca-45, Sc-47, Cr-51, Mn-53, Co-61, Ni- H-197, Tl-201, Ra-227, U-231, U-237, U-239, U-240, Np-239, Pu-234, Pu-235, Pu-237, etc. 100 P-103, Te-31, P-32, P-33, Fe-55, Co-60m, Zn-69, As-73, As-77, Sr- Cys-134, Pr-143, Pm-147, Pm-149, Sm-151, Dy-165, Er-169, Tm-171, W-185, Re-186, Os-191m etc. 1,000 Co-58m, Ge-71, Rh-103m, Fm-254 10,000

As shown in the table, in order to recycle the waste generated at dismantling of the nuclear power plant, it is necessary to decontaminate the radioactive material so as to be below the self-disposable regulatory release level and to check whether the contamination of the nuclides emitting alpha, You have to check every day through a full inspection. However, nowadays, the method of inspecting the radioactive waste generated during the operation of the nuclear power plant is to measure the surface contamination level of the radioactive waste by using the ion-ionization chamber such as the GM tube and the method of measuring the secondary light generated using the solid scintillator. However, it is a real problem to use existing inspection methods and inspection equipments in the field where large amount of radioactive waste is produced as in dismantling nuclear power plants. Therefore, a technique capable of full-scale inspection of large capacity should be developed.

Patent Registration No. 10-0925560 (Name: Radiation measuring apparatus having a three-dimensional movable detector)

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a method and apparatus for continuously, automatically, simultaneously inspecting alpha, beta and gamma rays emitted from a large volume of decontaminated waste, The present invention also provides a radioactive inspection system and method for detecting the degree of decontamination of surface contaminated radioactive waste for recycling of the radioactive waste.

According to an aspect of the present invention,

A shielding compartment providing a space through which the radioactive surface contamination test for the waste can be performed by closing the four sides;

A conveyor disposed inside the shielding compartment for conveying the tray on which the inspection object is placed;

A shielding portion disposed inside the shielding compartment for shielding four sides by a radiation shielding member and preventing the influence of the electromagnetic radiation on the radiation of the inspected object;

A distance measuring device disposed inside the shield to measure a height and a size of the object to be inspected;

A radiation measuring unit arranged inside the shield to move up and down to perform a radiation test on the object to be inspected, the measurement being performed at a height calculated by data measured by the distance measuring unit;

A radiation analyzer for analyzing the radiation measured by the radiation measuring unit; And

There is provided a continuous nuclear disassembly waste radioactive waste water inspection system including a control unit for sequentially performing a radioactivity inspection by controlling the inspection tray, the conveyor, the shielding unit, the distance measuring unit, the radiation measuring unit, and the radiation analyzer .

The system and method for checking the degree of decontamination against radioactive surface contamination of nuclear dismantling wastes according to the embodiment of the present invention and confirming the self-disposal allowable concentration for recycling have the following advantages.

First, it is advantageous to examine the radioactivity by the whole water inspection method regardless of the size, the capacity and other physical characteristics of the dismantled waste to be subjected to the radioactivity examination by inspecting the decontaminated nuclear dismantled waste test tray.

Second, since the radiation from the decontaminated disposal waste is measured inside the radiation shielding compartment made of a shielding member having excellent radiation shielding performance such as lead, it is possible to eliminate the influence from environmental radiation and surrounding electromagnetic waves, There is an advantage that accurate radioactivity value can be measured.

Third, by combining a conveyor and a plurality of radiation meters, a plurality of objects to be inspected are conveyed to the positions of the radiation meters by the conveyor, and the radiation is measured, so that the radiation measurement can be continuously and automatically performed. There is a simple advantage of knowing if the concentration is below the level of disposal radioactivity.

Thirdly, since a plurality of radiation meters can be arranged to perform radiation measurement on the object to be inspected, it is possible to shorten the inspection time of various types of large-capacity waste.

Fifth, the height, size, and weight of the object to be inspected are measured by the distance measuring machine and the weighing machine, and the accuracy of the inspection can be improved by reflecting the measurement in the radiation measurement.

Sixth, by connecting the distance measuring instrument and the weighing instrument with the control unit, the control unit controls the conveying speed of the conveyor at a slow speed in the case of heavy concrete, so that the radiation measuring time can be extended to perform more precise inspection, And the result of the distance measuring device is compared, it is advantageous that precise radiation measurement can be performed by driving the conveyor at a full speed even for a waste having a heavy pollution degree and a light weight or a large size.

Seventh, a measuring instrument capable of simultaneously detecting alpha, beta and gamma radiation and radiation can be used as a radiation measuring instrument using a scintillating material or a semiconductor measuring sensor, and a pre-processing is not required, , The inspection efficiency is high, and the resolution is high.

1 is a perspective view showing a nuclear waste disposal radioactivity inspection system according to an embodiment of the present invention.
2 is a plan view of Fig.
FIG. 3 is a side view schematically showing the structure of the radiation inspection system shown in FIG. 1. FIG.
FIG. 4 is a perspective view showing the structure of the measurement unit and the conveyor shown in FIG. 1. FIG.
5 is a perspective view showing the meter of the measuring unit shown in FIG.
6 is a block diagram showing the structure of the control unit shown in FIG.
7 is a flowchart showing a method of performing radiation measurement by the radiation inspection system shown in FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A nuclear waste disposal radioactive waste inspection system and method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 to 6, a nuclear disassembly waste radioactive waste inspection system 1 proposed by the present invention comprises a test tray 2 on which an object S to be inspected is loaded; A conveyor 3 for conveying the inspection object S contained in the inspection tray 2; A shielding part 5 for preventing an influence of an external electromagnetic line when measuring a radiation to be inspected S conveyed by the conveyor 3; A distance measuring device 24 disposed inside the shield 5 to measure the height and size of the object S; A radiation measuring unit 7 disposed inside the shielding unit 5 so as to be ascendable and descendable and simultaneously inspecting the alpha, beta and gamma radiation activity of the object to be inspected S; A radiation analyzer 9 for analyzing the radiation measured by the radiation measuring unit 7; The control section 11 that sequentially performs the radioactivity inspection by controlling the conveyor 3, the shielding section 5, the distance measuring device 24, the radiation measuring section 7 and the radiation analyzer 9 .

In the nuclear disassembly waste radioactivity inspection system having such a structure, the inspection tray 2 means a casing capable of moving the decontaminated nuclear disassembly waste to be subjected to the radioactivity inspection into the measuring section.

In the present invention, a shielding compartment (4) having a radiation shielding performance sealed at four sides is installed outside the radiation measuring part, and the shielding compartment (4) is preferably structured such that the inner space is shielded from the outside. The shielding compartment 4 is a structure that can be carried by a vehicle or the like. Therefore, by installing the radiation inspection system inside the shielding compartment 4, it is possible to move to the site of the dismantling of the nuclear power plant, and continuously conduct the radiation total water inspection without being affected by the environmental radiation around.

A conveyor on which the inspection tray 2 is placed is disposed in the radiation shielding compartment 4 to transfer inspection objects S such as nuclear disposal wastes of various types and shapes. Can be performed.

At this time, the conveyor 3 has a structure in which a plurality of rollers are driven by a motor as a conveyor having a conventional structure capable of conveying the object S to be inspected. The conveyor 3 is disposed in the outward direction from the entrance side of the shielding compartment 4 including the inspection tray 2 and the shield 5 is further disposed in the middle of the conveyance path and in the front / .

Therefore, when the conveyor 3 is driven in a state where the inspection object S is placed on the conveyor 3, the inspection object S is supplied to the shielding portion 5 and the radiation measurement is performed. After the measurement, (S) to the outside of the container (5).

The radiation shielding unit 5 is configured to shield the inside of the radiation shielding state so that the radiation inspection of the inspection object S supplied through the conveyor 3 can be performed in a stable state with minimized external influences.

The shielding portion 5 is made of a radiation shielding material and is formed of a wall 13 for shielding all sides; And doors D1 and D2 that are openably and rearwardly disposed on the front and rear sides of the wall 13, respectively.

In the shielding portion 5 having such a structure, the wall 13 may be formed of a material capable of shielding the radiation. For example, it can be formed of a lead material mainly used in the past or a material having high density such as tungsten.

By arranging the walls 13 in four directions, a space for inspecting the inside can be formed, thereby preventing the influence of external energy, for example, external electromagnetic radiation, from being exerted during radioactivity inspection of the metabolites.

The doors D1 and D2 are disposed in front of and behind the shield 5 so that the inspection object S can be supplied to or discharged from the inside of the shield 5. [

Of course, the doors D1 and D2 also function as a radiation shielding material, so that the influence of external electromagnetic radiation during the inspection can be effectively blocked.

The doors D1 and D2 are configured to be lifted and lowered by a motor and can be opened and closed by driving the motor by a signal from the control unit 11. [

By arranging a plurality of radiation measuring sections 7 inside the shielding section 5, it is possible to perform the alpha, beta and gamma ray inspection on the object S in order or simultaneously.

At least one or more radiation measuring sections 7 may be arranged, for example, one or more radiation measuring sections may be arranged. Since one or more of the radiation measuring units have the same structure, the one or more radiation measuring units 7 will be described below.

The radiation measuring unit 7 includes a radiation measuring instrument 15 for examining alpha, beta and gamma radiation emitted from the object S to be inspected; And a lift portion 19 for moving the radiation measuring instrument 15 up and down.

The radiation meter 15 preferably means NaI (Tl) or a plastic measuring instrument. In addition, a measuring member capable of improving the resolution, such as ZnS film, may be attached to the surface of the instrument in order to increase the measurement rate of radiation with low material permeability, such as alpha and beta. In the present invention, it is judged whether or not the waste containing alpha, beta and gamma-emitting nuclear species is below the self-disposal allowance criteria by the whole survey method.

Therefore, the radiation measuring instrument 15 measures the efficiency and resolution of the measuring instrument under a specific operating condition using a standard source of cesium (Cs-137), which is a main inspecting nuclear species.

Since existing HPGe instruments must supply LN2 gas, it is difficult to operate continuously for 24 hours and time delay occurs because sample is pretreated.

Therefore, in this embodiment, a meter capable of detecting radiation using a scintillation material or a semiconductor can be used, and there is a merit that a continuous operation is possible because a pre-process is not required, and inspection efficiency is high and detection efficiency is high.

The NaI (Tl) or ZnS film-attached plastic measuring instrument 15 used for radiation detection is classified as an inorganic scintillator as a scintillation detector. In particular, the NaI (Tl) detector is made of thallium-activated sodium iodide As the density and atomic number are relatively high, gamma ray detection with high efficiency is possible.

Such a NaI (Tl) or plastic meter 15 has a peak emission spectrum at a few hundred nanometers and exhibits the highest light yield in all scintillators.

According to the Nuclear Safety Act and the Radiation Emergency Countermeasures Act, radioactive nuclides generated by nuclear accidents are Cs-134, Cs-137, Ru-103, Ru-106, Sr-89, U-235, U-238, Am-241, Pu-238, Pu-239, Pu-240, Pu-242 and H-3.

The radioactive materials that can affect the human body are cesium (Cs-137), strontium (Sr-90), iodine (I-131), plutonium (Pu-239) Strontium, which is a beta-ray radioactive substance, is extremely small in amount, plutonium is weak in permeability due to alpha emission and has a self-shielding effect. However, it is difficult to measure the amount of iodine And cesium, as well as radioactivity contamination by radionuclides that release alpha or beta radiation.

In order to measure the radioactivity released from the waste contaminated with the radioactive nuclide of low self-disposal radionuclide such as I-129 or Co-60, Cs-137 in Table 1, alpha ray, beta ray or gamma ray radiation is measured A measuring system with high precision and accuracy must be provided.

In order to measure this level, there must be conditions for nuclide analysis and lead shielding for natural radioactive decay. The characteristics of the instruments that can be utilized for radiation and radiation measurements in the present invention are compared as shown in the table below, and various types of instruments can be used for the present invention.

division Gaseous type detector Semiconductor detector Flash type detector Sensor type Ion chamber, proportional counter, GM counter, etc. HPGe, CdTe, Hgl2, GaAS, etc. NaI (Tl), CsI (Tl), ZnS (Ag), etc. Detection principle Ionization (gas) Ionizing action (solid) Excitation (solid, liquid) main purpose Alpha / beta / gamma measurement Gamma ray and x-ray measurement Gamma ray, x-ray, alpha ray etc. Detection lower limit value > 10,000 Bq / Kg ≪ 10 Bq / Kg ≪ 10 Bq / Kg Resolution Poor Excellent energy resolution Relatively good Nuclide analysis impossible possible possible Detection time Within minutes 4 to 8 hours 10 to 30 minutes Characteristic Manual operation, limited use due to low detection limit Manual operation
Cooling required during measurement
Not measurable at room temperature Manual inspection, automatic full inspection, robust
Low degradation time enables high counting rate Action / Price Easy / Cheap Complex / expensive Easy / relatively inexpensive Dead time Counting tube: Water - Hundreds of μSEC Number - tens of μSEC Tens of nSEC

The radiation measuring unit 7 is composed of a plurality of measuring instruments 15a, 15b and 15c and the plurality of measuring instruments 15a, 15b and 15c sequentially inspect the inspection target S to enable quick radiation measurement.

For example, when three instruments 15a, 15b and 15c, that is, first to third instruments, are arranged, the respective instruments are arranged apart from each other along the direction in which the inspected object is conveyed.

Therefore, when the object S to be inspected is conveyed by the conveyor 3 and transferred to the inside of the shielding portion 5, the first inspected object S is conveyed to the position of the first measurer 15a. Then, the second inspection object S is transported to the position of the second measuring instrument 15b, and the third inspection object S is transported to the third measuring instrument 15c.

Since the inspection objects S are transported to the positions of the first to third meters 15a, 15b and 15c, respectively, the radiation measurement for each inspection object can be simultaneously performed, and the inspection time can be shortened .

Of course, the meters 15a, 15b, and 15c may measure not only the objects S to be inspected S to one, but also the measurement may be selectively performed. .

For example, the third measuring instrument 15c temporarily checks whether or not the object to be inspected is contaminated. The first measuring instrument 15a measures the object to be inspected S It is a method to conduct inspection.

As described above, the control unit 11 can perform the inspection at the same time or selectively perform the measurement at the same time by appropriately controlling the inspection order of the first to third meters 15a, 15b, and 15c.

On the other hand, the Na (Tl) or the plastic scintillator 15 can be raised and lowered up and down by the lifting unit 19. The elevating unit 19 refers to an elevating unit that elevates and lowers the measuring instrument 15, and may include various elevating equipment.

For example, the elevating portion 19 can be fixed to a frame F arranged inside the shielding portion 5 as a cylinder type or a motor type so that the measuring device 15 can be moved up and down. In the case of the cylinder system, the piston (22) is mounted on the cylinder (20) such that it can move back and forth by hydraulic pressure or air pressure. The upper portion of the cylinder 20 is fixed to the frame F and the measuring instrument 15 is fixed to the tip of the piston 22. [

Therefore, when the cylinder 20 is operated by the signal of the control unit 11, the piston 22 is lowered down and the meter 15 is also lowered. On the other hand, when the piston 22 is raised, Rise.

In this way, the elevating portion 19 can move the measuring instrument 15 up and down within the shielding portion 5.

Of course, in the case of the motor system, the motor shaft is moved up and down by the motor according to the signal of the control unit 11, and the meter 15 can also ascend and descend.

In addition, a distance measuring instrument 24 may be additionally provided for the meter 15 to descend to the correct position.

The distance measuring device 24 measures the distance and size between the distance measuring device 24 and the inspected object S transferred to the inside of the shielding part 5 and interlocks with the measuring device 15 so that the measuring device 15 descends to an appropriate height, To be measured.

The distance measuring instrument 24 includes various distance measuring instruments, for example, an infrared measuring sensor or a laser measuring sensor.

The distance measuring device 24 irradiates the surface of the object S to be inspected with an infrared ray or a laser by the signal of the control part 11 when the object S is conveyed to the inside of the shielding part 5 by the conveyor 3 Thereby measuring the distance from the object S to be inspected. At this time, the size of the object S to be inspected can be measured by continuously measuring the distance while moving the distance measuring instrument 24 in the X-axis direction.

When the numerical signal measured by the distance measuring instrument 24 is transmitted to the control section 11 as described above, the control section 11 transmits a signal to the ascending and descending section of the measuring instrument 15 according to the measured distance, .

At this time, the descending height of the measuring instrument 15 is set in advance in the control unit 11. [ That is, in consideration of the thickness, size, and the like of the inspection object S, a height suitable for detecting the scattering line is input in advance. Accordingly, when the value measured by the distance measuring unit 24 is transmitted to the control unit 11, the control unit 11 calculates the height from the database 44 according to the value and transmits it to the elevating unit 19. [

The elevator 19 can move the measuring instrument 15 to the appropriate height by raising and lowering the measuring instrument 15 by this signal.

On the other hand, the weight of the object S to be inspected can be measured by disposing the weight sensor 26 on the shield 5. The weight sensor 26 may include various types of sensors, for example, a load cell.

The weight sensor 26 can be placed on the inner bottom of the shield 5 or on the conveyor 3 to measure the weight of the object S to be inspected.

Then, the measured weight value is transmitted to the control unit 11, and the control unit 11 reflects the converted radiation measurement unit.

In addition, as another embodiment of the present invention, the control unit 11 controls the motor speed of the conveyor 3 according to the weight of the object to be inspected inputted from the weight sensor 26, The radiation measurement time can be extended. That is, when the weight of the object to be inspected is heavy, it can be judged that the degree of contamination is high, so it is necessary to measure the radiation more precisely.

Conversely, if the weight of the object to be inspected is light, the radiation measurement time can be reduced by relatively increasing the motor speed.

By varying the conveying speed of the conveyor 3 according to the weight of the object to be inspected, the radiation measurement time can be efficiently controlled.

Meanwhile, not only the weight sensor 26 but also the distance measuring instrument 24 may be interlocked with the control unit 11. [

In other words, not only concrete but also waste such as rubber or foaming resin are large in size but light in weight.

In this case, when the speed of the conveyor is adjusted by simply determining the weight, it is determined that the degree of radiation contamination is low, so that the conveyor can not be precisely measured by moving the conveyor at a high speed.

Therefore, it is necessary to compare and analyze the result measured by the distance measuring device 24 and the result measured by the weight sensor 26 with each other.

That is, the result of the weight sensor 26 is compared with the result of the distance measurer 24. If the result of the distance measurer 24 is equal to or greater than a predetermined value or the result of the weight sensor 26 is less than a predetermined value, It can be judged that the size of the object to be inspected is large but the weight is light.

Therefore, since such an object to be inspected may also have a high degree of radioactive contamination, the control unit 11 drives the conveyor 3 at a relatively low speed to precisely measure the radiation.

Meanwhile, the radiation analyzer 9 receives the radiation measurement signal transmitted from the measurement unit 7, analyzes the radiation intensity, and transmits the radiation intensity to the controller 11. The radioactivity analyzer 9 means various types of analyzers, for example, a multi-peak analyzer 9.

The multi-peaking analyzer 9 is an apparatus for analyzing the energy spectrum of radiation. The multi-peaking analyzer 9 measures a plurality of output signals of various heights according to the energy of the radiation coming from the radiation meter 15, Can be analyzed at the same time.

The control unit 11 determines whether the object to be inspected is contaminated or not based on the radiation intensity value received from the radiation analyzer 9,

6, the control unit 11 includes a conveyor 3, a radiation measuring unit 7, a shielding unit 5, and input / output modules 32 and 34 for inputting and outputting data from the radiation analyzer 9 )and; A distance measuring and meter moving module 36; A radiation measurement module 38; A conveyor transfer module 40; A process module (42) for conducting an inspection process in cooperation with each module; And a database 44.

The distance measuring and measuring instrument moving module 36 calculates the distance to the inspection object S by interlocking with an infrared sensor or a laser sensor which is a distance measuring instrument and drives the motor by transmitting a signal to the elevating portion 19, So that it can ascend and descend to a predetermined position.

Since the height of the meter 15 according to each distance is stored in the database 44 in advance, the distance measurement and meter moving module 36 fetches the corresponding value and transmits it to the elevator 19 to drive the motor, (15).

Then, the radiation measurement module 38 controls the measurement process such as the start, the progress, and the completion of measurement by transmitting a signal to the meter 15. Further, the radiation measuring module 38 converts the measured and transmitted data, that is, the radiation dose Roentgen, into the radiation intensity (Bq / g or CPS).

The conveyor transfer module 40 interlocks with the conveyor 3 to supply or discharge the object S to / from the shield 5 according to a predetermined inspection schedule.

Then, the process module 42 controls processes throughout the radiation examination. That is, when the object S to be inspected is placed on the conveyor 3, a signal is transmitted to the conveyor transfer module 40 to drive the conveyor 3 to transfer the object S to the shielding part 5.

When the object S reaches the inside of the shield 5, a distance measurement and a signal are transmitted to the meter moving module 36 so that distance measurement and radiation measurement can be performed.

Then, a signal is transmitted to the radiation measurement module 38 so that the radiation measurement can be performed. When the radiation measurement is completed, the radiation intensity is calculated through the radiation analyzer 9.

When the radiation measurement process is completed, a signal is transmitted to the conveyor transfer module 40 to drive the conveyor 3 to discharge the inspection object S to the outside of the shielding part 5. [

On the other hand, if it is determined that the radioactive contaminant is a radioactive contaminant having a self-disposal allowable concentration or more determined by the inspection result, the process module 42 transmits a signal to the alarm unit to inform that it is a contaminant. Such an alarm part can guide the fact of radioactive contamination in various ways, for example, by emitting a warning sound, blinking an emergency lamp, or simultaneously displaying the radiation intensity through a display or the like, It can be informed that the radioactive contaminated state is present.

Then, the contaminated inspection object S is discharged to the auxiliary conveyor 54, which is not a normal conveyance route, when measuring the radioactive contamination above its own disposal allowable concentration.

That is, as shown in Fig. 4, the auxiliary conveyor 54 is disposed on one side of the conveyor 3, and the direction changing lever 50 is also disposed.

This direction changing lever 50 has a structure that is mounted on the upper portion of the conveyor 3 and is rotatable by the motor 52. Therefore, when the motor 52 is driven by the control of the process module 42, if the direction changing lever 50 rotates in the clockwise direction, the contaminated inspection object S on the conveyor 3 is pushed and the auxiliary conveyor 54 ).

If it is determined that the contaminated object S is contaminated with a radioactivity allowable concentration or higher, it can be easily sorted and separated by being automatically transferred to the auxiliary conveyor 54 by the direction changing lever 50.

Hereinafter, a method for inspecting wastes contaminated by the self-disposal allowable radioactive concentration according to an embodiment of the present invention will be described in detail.

As shown in Fig. 1, Fig. 4, Fig. 5 and Fig. 7, the inspection method of radioactive surface contaminated nuclear waste disposal waste proposed by the present invention comprises the steps of (a) (S50); (b) transferring the object S to the shielding unit 5 (S100); (c) measuring a size and a distance of the inspected object S (S110); (d) measuring radiation on a plurality of objects to be inspected (S120); (e) a step (S130) of the control unit 11 judging the surface contamination degree by the measured radiation data; (f) selecting and separating the object to be inspected S if it is determined that the radioactive contamination is equal to or higher than the tolerance standard, and discharging the object to the outside of the shielding unit 5 if it is judged that radioactive contamination is below the tolerance standard (S140).

In this inspection method, in step (a) (S50), residual radioactivity test of nuclear disassembly waste in a shielding compartment in which a radioactivity testing system is installed is performed at the waste generation site in a full inspection manner.

When the disassembled and decontaminated waste is loaded on the inspection tray, step (S100) is performed. In step (b), the inspection object S loaded on the inspection tray is placed on the conveyor 3 , The conveyor 3 is driven by the signal of the control unit 11.

That is, the controller 11 transmits a signal to the distance measuring and meter moving module 36 to drive the motor of the conveyor 3 so that the conveyor 3 is transferred toward the shield 5 (S15).

The object S in the plurality of inspection trays which are placed on the conveyor 3 can be transferred to the shielding portion 5 by advancing the conveyor 3 in the direction of the shielding portion 5. [

At this time, since the number of the objects S to be inspected is plural, for example, three, the first inspected object S reaches the position of the first measurer 15a and the second inspected object S reaches the second measurer 15b And the third inspection object S transports the conveyor 3 to reach the third measuring instrument 15c.

When the conveying step S100 of the inspected object S is completed, a step S110 of measuring the distance and the size with respect to the inspected object S proceeds.

In this step, the controller 11 drives the distance measuring instrument 24 by transmitting a signal to the distance measuring and measuring instrument moving module 36. When the distance measuring instrument 24 is driven, the distance measuring instrument 24 measures the height of the object S by irradiating the surface of the object S with infrared rays or a laser (S20).

The distance measuring device 24 continuously measures the height of the object S while moving in the conveying direction of the conveyor 3 so that the size of the object S can be finally measured.

When the distance measuring unit 24 measures the size and height of the object S (S110), the radiation measuring step S120 proceeds.

That is, in the radiation measurement step (S120), the measured height and size data are transmitted to the control unit (11). The control unit 11 calculates the descent height of the radiation measuring unit 7 by calculating the input data (S30).

At this time, when there are a plurality of radiation measuring units 7, the radiation measuring unit 7 calculates an appropriate height according to each of the corresponding objects S to be inspected.

After calculating the descent height, the control unit 11 moves the motor of the radiation measuring unit 7 down by transmitting a signal to the radiation measuring module 38. When the radiation measuring unit 7 reaches the target height, it is stopped.

In this state, the radiation measuring unit 7 measures the radiation generated from the object S.

At this time, the first to third measuring instruments 15a to 15c simultaneously measure the radiation for each inspected object S (S40). Therefore, the radiation measurement time for the object S to be inspected can be shortened.

Since the measured radiation value is Roentgen, the radiation measuring module 38 converts the radiation intensity into the radiation intensity (Bq / g) by the radiation analyzer 9.

When the radiation measurement step S120 is completed as described above, the step of determining the degree of contamination of the radioactive surface of the object to be inspected S proceeds to step S130.

That is, the controller 11 compares the radiation intensity input from the radiation measuring module 38 with a predetermined reference value to determine whether the radiation level of the object to be inspected S has exceeded its own permissible radiation concentration (S150).

For example, in the case of I-131, the intensity of radiation is compared with 0.1 or more as a reference value (Bq / g) as shown in Table 1, or 10 or more as Cs-134 and Cs-137.

When the step of determining whether the radiation intensity is at the contamination level (S130) is completed, (e) the step (S140) is performed.

That is, if it is determined that the radiation intensity is higher than the self-disposal allowable concentration, the control unit 11 transmits a signal to the alarm unit to generate a warning sound (S52).

By driving the motor 52 of the direction changing lever 50, the direction changing lever 50 rotates along the direction of the arrow on the conveyor 3 to transfer the contaminated object S to the auxiliary conveyor 54 (S54).

Through this process, the radiation measurement on the object S can be carried out automatically and continuously.

1: Radiation Inspection System
2: Inspection tray
3: Conveyor
5: Shielding
7:
9: Radiometer
11:

Claims (9)

A shielding compartment providing a space through which the radioactive surface contamination test for the waste can be performed by closing the four sides;
A conveyor disposed inside the shielding compartment for conveying the tray on which the inspection object is placed;
A shielding portion disposed inside the shielding compartment for shielding four sides by a radiation shielding member and preventing the influence of the electromagnetic radiation on the radiation of the inspected object;
A distance measuring device disposed inside the shield to measure a height and a size of the object to be inspected;
A radiation measuring unit arranged inside the shield to move up and down to perform a radiation test on the object to be inspected, the measurement being performed at a height calculated by data measured by the distance measuring unit;
A radiation analyzer for analyzing the radiation measured by the radiation measuring unit; And
And a control unit for sequentially performing a radioactivity test by controlling the test tray, the conveyor, the shielding unit, the distance measuring unit, the radiation measuring unit, and the radiation analyzer. The method according to claim 1,
The radiation measuring unit includes a plurality of radiation measuring devices simultaneously measuring alpha, beta and gamma rays emitted from the object to be inspected and examining the radioactivity; And a lifting unit for lifting and lowering the radiation measuring instrument,
Wherein the plurality of radiation measuring instruments are scales using a scintillation material or a semiconductor type detector, wherein three or more radiation detecting devices can be simultaneously inspected for a plurality of objects to be inspected. 3. The method of claim 2,
The plurality of radiation meters may be arranged at predetermined intervals in the same direction with respect to the direction in which the inspection targets are conveyed so that the inspection targets sequentially arrive at the respective radiation meters,
Wherein the radioactive waste disposal apparatus is capable of selectively reaching a plurality of radiation meters. The method according to claim 1,
The control unit includes an inspection tray, a conveyor, a radiation measuring unit, a shielding unit, an input / output module for inputting and outputting data from the radiation analyzer, A distance measuring and meter moving module; A radiation measurement module; A conveyor conveying module on which the inspection tray is placed; A processor module for performing an inspection process in cooperation with each module; Nuclear waste disposal radioactivity inspection system including database. The method according to claim 1,
And a weight measuring sensor for measuring the weight of the object to be inspected and transmitting the measured weight to the control unit, thereby detecting the height and weight of the object to be inspected in cooperation with the distance measuring unit and the control unit. Inspection system. 6. The method of claim 5,
Wherein the control unit controls the motor speed of the conveyor according to the weight of the object to be inspected inputted from the weight measuring sensor so that the weight of the object to be inspected is transferred to the slower speed to prolong the radiation measurement time. 6. The method of claim 5,
The control unit 11 compares the result of the weight sensor 26 with the result of the distance measuring unit 24 and determines whether the result of the distance measuring unit 24 is equal to or greater than a predetermined value, , It is determined that the object to be inspected is large, but the weight is light and the degree of contamination is high, so that the contamination degree is high, and the conveyor 3 is driven at a relatively low speed, . (a) transporting to a site a radiation shielding compartment containing a radiation inspection system by a transfer means;
(b) loading the inspection object onto the inspection tray and transferring the inspection object to the inside of the shield by the conveyor;
(c) measuring a size and a distance to a plurality of objects to be inspected by a distance measuring instrument inside the shield;
(d) performing a radiation measurement on an object to be inspected by a plurality of radiation meters, wherein a plurality of radiation meters can simultaneously perform measurement on each object to be inspected;
(e) judging whether or not the control unit is contaminated by the measured radiation data; And
(f) separating the object to be inspected if it is judged that the object is contaminated at a concentration exceeding the allowable concentration of the object, and discharging the object to the outside of the shield when it is judged that the object is below the allowable concentration. 9. The method of claim 8,
(f), when the control unit determines that the tolerance level is equal to or higher than the allowable concentration, the control unit transmits a signal to the direction changing lever to rotate the inspection tray so that the inspection tray on which the inspection object on the conveyor is immobilized can be transferred to the auxiliary conveyor and separated. Detection method of total waste radioactive waste.

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