GBZ 132-2002 Industrial gamma ray flaw detection health protection standard
Some standard content:
ICS13.100
National occupational health standard of the People's Republic of China GBZ132-2002
Health protection standard for industrial gamma defect detecting
Radiological protection standards for industrial gamma defect detecting2002-04-08Promulgated
Ministry of Health of the People's Republic of China
Implementation on 2002-06-01
Normative references
Terms and definitions
?Radiological protection performance requirements for radiographic flaw detectorsRadiological protection requirements for fixed flaw detection
Radiological protection requirements for mobile flaw detection
Safety requirements for radioactive sources
Radiological protection monitoring
Appendix A (Normative Appendix) Determination of protective layerAppendix B (Normative Appendix) Determination of control area
This standard is formulated in accordance with the Law of the People's Republic of China on the Prevention and Control of Occupational Diseases. In case of any inconsistency between the original standard GB18465-2001 and this standard, this standard shall prevail. Chapters 4 to 8 and Appendix A and Appendix B of this standard are mandatory contents, and the rest are recommended contents.
During the preparation of this standard, the contents of GB14058, DIN54115 Part 1 and its annex and DIN54115 Part 5 were mainly referred to, and Appendix A and Appendix B of this standard were prepared in combination with the actual situation in my country. They are normative appendices. This standard is proposed and managed by the Ministry of Health.
The drafting unit of this standard: Institute of Radiation Medicine, Shandong Academy of Medical Sciences. The main drafters of this standard: Deng Daping, Hou Jinpeng, Zhu Jianguo, Wen Jihui, Wang Chunliang. This standard is interpreted by the Ministry of Health.
Industrial Y-ray Flaw Detection Health Protection Standard
1 Scope
GBZ132-2002
This standard specifies the protection performance of Y-ray flaw detectors and the radiation protection and related monitoring requirements during their use.
This standard applies to the practice of non-destructive testing of the internal structure of metal components using γ-ray flaw detectors.
2 Referenced standards
The clauses in the following documents become the clauses of this standard through reference in this standard. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties reaching an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For any undated referenced document, the latest version shall apply to this standard.
GB4075 Classification of sealed radioactive sources
GB11806 Regulations on safe transportation of radioactive materials GB/T14058 Y-ray flaw detector
Terms and definitions
The following terms and definitions apply to this standard. 3.1
Mobile flaw detection The process of using a portable or mobile Y-ray flaw detector to detect flaws outdoors, in a production workshop or at an installation site.
Stationary flaw detection
stationary defect detecting
The process of performing radiographic flaw detection in a dedicated gamma-ray flaw detection room using a fixed or limitedly movable flaw detector.
gamma defect detectingroomA dedicated irradiation room with a certain shielding effect and a gamma-ray flaw detector and an object to be inspected for radiographic flaw detection.
4 Requirements for the performance of radiological protection of gamma-ray flaw detectors 4.1 The source container shall comply with the test requirements of Article 5.3 of GB/T14058, and the kerma rate of the air around it shall not exceed the values in Table 1 Table 1 Control value of kerma rate of air around source container (mGy·h) Flaw detector category
Handheld
Mobile
Fixed
Outer surface of container
Distance from outer surface of container
4.2 When depleted uranium is used as shielding material for source container, its protection against beta rays shall comply with the requirements of Article 5.3.1 of GB/T14058.
4.3 The source container of each gamma-ray flaw detector and the sealed source therein must have a mark that complies with the requirements of Articles 8.1.1 and 8.1.2 of GB/T14058. 4.4 The performance of the safety devices of the Y-ray flaw detector, such as the safety lock, interlocking device, source position indicator, safety device for system failure, and device to prevent illegal operation, shall comply with the requirements of Article 5.4 of GB/T14085.
4.5 The safety of the source holder shall comply with the requirements of Article 5.5 of GB/T14085. 4.6 According to different needs, the length of the radioactive source transmission device shall be shortened as much as possible. After each photo, the radioactive source must be able to return to the source container immediately and enter the closed state. 4.7 The product manual shall indicate the model, specifications and main technical indicators, as well as the equipment maintenance, storage and transportation methods. It shall also include: the type and characteristics of the radioactive source used, the leakage dose level of the outer surface of the source container, safety measures, automatic shutdown function and the handling methods of common accidents. 5.1 The construction of the Y-ray flaw detection room (including radiation protection walls, doors, windows, radiation protection labyrinths) should fully consider various factors such as direct radiation, scattering and shielding materials and structures, and determine the protection thickness in accordance with the requirements of Appendix A (Normative Appendix) of this standard. 5.2 The dose rate 5 cm outside the radiation protection wall should be less than 2.5 μGy·h. 5.3 There must be a fixed radioactive hazard sign at the entrance of the radiation protection door, and a conspicuous "No Entry" warning sign during irradiation; sound and light alarm devices must be installed at the entrance of the flaw detection room and the entrance and exit of the inspected objects. The device should be automatically connected when the Y-ray flaw detector is working and can automatically retract the radioactive source into the source container when someone passes by; the protection performance of the radiation protection door should be the same as that of the wall on the same side, and its The dose rate 5cm outside the room should be less than 2.5uGy·h, and a door interlocking device and a working indicator light should be installed; a fixed dosimeter should be installed at an appropriate location in the machine room. 6 Radiation protection requirements for mobile flaw detection
6.1 Before conducting flaw detection operations, the workplace must be divided into a control area and a supervision area. 6.2 The air kerma rate outside the control area boundary should be lower than 40uGy·h. A clearly visible "No entry to radioactive workplace" warning sign must be hung at its boundary. No one is allowed to enter this range without permission. Ropes, chains and similar methods can be used, or supervisors can be arranged to implement manual management. The calculation method of the control area range is shown in Appendix B (Normative Appendix). 6.3 The supervision area is located outside the control area, and relevant personnel are allowed to move around in this area. Training personnel or detectors Visitors may also enter this area. The boundary dose should not exceed 2.5μGy·h. There should be a "Caution, ionizing radiation" warning sign at the boundary. The public is not allowed to enter this area. 6.4 When performing flaw detection operations, the distance between the Y-ray flaw detector and the object being inspected, the irradiation direction, time and shielding conditions must be considered to ensure that the exposure dose of the operators is lower than the annual dose limit, and should be as low as reasonably achievable. 7 Safety requirements for radioactive sources
7.1 The level of sealed sources selected shall be selected in accordance with GB4075. The unprotected source is level 43515 and the source in the device is level 43313
7.2 The replacement of radioactive sources shall be approved by the local radiation health protection department and carried out under the supervision of protection professionals. In a fully shielded device, Use a long-distance grabber and support device.
When transferring sealed sources from transport containers to source containers or from source containers to transport containers, auxiliary equipment that facilitates replacement operations and devices with adequate shielding performance must be used. The equivalent dose received by operators during a replacement process should not exceed 0.5mSv. 7.3 The replacement of radioactive source holders should be approved by the competent department of the user unit and the local radiation health supervision department. If the loading and unloading of source containers with radioactive sources and source holders is carried out by thrusters, appropriate replacement containers with adequate shielding must be used. 7.4 Discarded radioactive sources shall be handled or disposed of in accordance with relevant national regulations, and detailed records shall be archived and preserved.
7.5 The transportation of radioactive sources shall be carried out in accordance with the relevant provisions of GB11806. 7.6 Source containers or radioactive sources shall be stored in a dedicated radioactive source warehouse. 7.7 Under the guidance of the local radiation health protection competent department, the user unit shall formulate an appropriate emergency plan and make corresponding emergency preparations. The plan content includes: work procedures, organizational structure, personnel training, emergency plan exercises, emergency facilities, etc. 7.8 The operation site must be equipped with appropriate emergency protection equipment, such as: protective shelters with sufficient shielding thickness, tunnel shielding blocks, clamps with handles not less than 1.5 meters, metal wires of appropriate length, pools, sandbags, etc.
8 Radiation protection monitoring
8.1 Personal dose monitoring of operators
8.1.1. Y-ray flaw detection operators must conduct regular personal dose monitoring and establish personal dose files and health management files. The personal annual dose limits are as follows: a) 20mSv average annual effective dose for 5 consecutive years; b) 50mSv effective dose in any single year; c) 150mSv equivalent dose to the eye lens in a year; and d) 500mSv equivalent dose to the limbs (hands and feet) or skin in a year. 8.1.2 Operators should also be monitored for doses of accidents and detailed records should be kept. 8.2 Monitoring of protective performance of Y-ray flaw detectors
8.2.1 When producing Y-ray flaw detectors, type inspection and factory inspection should be carried out in accordance with the requirements of GB/T14058.
8.2.2 The radiation health technical service agency in the location of the user unit shall conduct acceptance inspection on the Y-ray flaw detector according to the radiation protection performance requirements of Chapter 4 of this standard. The shielding effect test required by Article 4.1 of this standard shall be carried out in accordance with Article 6.1 of GB/T14058. It can only be used after passing the inspection. 8.2.3 The user unit shall regularly inspect the performance of the safety device, and the radiation health technical service agency shall conduct it once a year.
8.2.4 After the flaw detector is moved, the part-time protection personnel must use the corresponding instruments to conduct the performance inspection of the safety device.
8.2.5 The protection department shall conduct a leakage test on the sealed radioactive source once a year. 8.3 Protection monitoring of the workplace
8.3.1 Protection monitoring of fixed flaw detection workplaces 8.3.1.1 Before the flaw detection room is put into use, an acceptance inspection must be carried out, and it can only be used after passing the inspection. 8.3.1.2 Before work every day, the flaw detection operator shall check the performance of the safety device and interlocking device and the status of the warning signal and sign. Check whether there are people staying in the flaw detection room. 8.3.1.3 After each flaw detection operation, the operator shall use reliable radiation instruments to check whether the radioactive source has returned to a safe position. The source container shall be monitored and detailed records shall be kept when entering and leaving the source library. bZxz.net
8.3.1.4 The radiation health technical service agency in the user unit’s location shall measure the radiation level of the operating site and the adjacent area of the flaw detection room once a year, and make evaluations or improvement suggestions based on the measurement results. When the activity of the radioactive source increases, the above radiation level shall be remeasured and appropriate improvements shall be made based on the measurement results. 8.3.2 Radiological protection monitoring of mobile flaw detection workplaces 8.3.2.1 Before each flaw detection operation, the flaw detector shall be checked in accordance with Article 8.3.1.2 of this standard, and the control area shall be checked to ensure that there are no people in the control area before the radioactive source is exposed. 8.3.2.2 When the workplace is activated, the radiation level shall be measured around the boundary of the control area and adjusted according to the requirement of not exceeding 40μGy·h. 8.3.2.3 Establish a radiation inspection system at the operation site and regularly observe the location and status of the radioactive source.
8.3.2.4 After the flaw detection operation is completed, the work in Article 8.3.1.3 of this standard should be carried out. Al Principle
Appendix A
(Normative Appendix)
Determination of protective layer
A1.1 The direction of the useful wire bundle must be considered when determining the protective layer. If the direction of the useful wire bundle is not restricted, the protective layer in all directions shall be determined in accordance with Section A2. If the useful wire bundle is only in a limited direction, except for the protective layer in this limited direction determined in accordance with Section A2, the leakage radiation protection layer in all other directions shall be determined in accordance with Section A3.
A1.2 The total attenuation of the multi-layer protection composed of different shielding materials is equal to the product of the attenuation of each protective layer.
A2 Protective layer against useful radiation
A2.1 Calculate the required useful radiation attenuation FK·a
Fw=will
In the formula: K is the measured or calculated according to Section A2.2 kerma rate (mGy/h) at a distance ao (m) from the radiation source in the useful radiation beam, a is the distance from a point of the radiation source (m), and K. is the maximum allowable kerma rate (mGy/h) at a distance ao from the radiation source. A2.2 At a distance ao, the maximum kerma rate K of the point can be calculated according to formula (2) from the expected maximum radioactivity A (GB) of the radiation source and the kerma constant Tk (see Table A1).
Radiation source
Kerma constant Ik (mGy·m/h·GBg)6oco
The thickness of the protective layer that protects against useful radiation beams can be found in Figures A1 and A2. By dividing the mass thickness given in Figures A1 and A2 by the density of the shielding material (g/cm), the thickness of the protective layer in cm can be obtained (see A2.4 for details). A2.4 Formula calculation of protective layer
The thickness d (cm) of the protective layer can also be calculated using the value of the linear attenuation coefficient u in Table A2 according to formula (3), strictly applicable to the linear range of curve F>10 in Figures A1 and A2.
A2.5 The description of all protective walls that protect against useful radiation beams must be indicated on the radiation protection structure diagram, including the wall thickness, shielding material name and thickness. A3
Protective layer to prevent radiation leakage
Protective layer to prevent radiation leakage from source container or shielding. The required attenuation Fp is calculated according to formula (4):is the maximum permissible kerma rate (mGy/h) at a distance from the radiation source. A2.2 At a distance ao, the maximum kerma rate K at that point can be calculated by the expected maximum radioactivity A (GB) of the radiation source and the kerma constant Tk (see Table A1) according to formula (2).
Radioactive source
Kerma constant Ik (mGy·m/h·GBg)6oco
The thickness of the protective layer against the useful radiation beam can be found in Figures A1 and A2. By dividing the mass thickness given in Figures A1 and A2 by the density of the shielding material (g/cm), the thickness of the protective layer in cm can be obtained (see A2.4 for details). A2.4 Formula calculation of the protective layer
The thickness d (cm) of the protective layer can also be calculated using the value of the linear attenuation coefficient u in Table A2 according to formula (3), strictly applicable to the linear range of curve F>10 in Figures A1 and A2.
A2.5 The radiation protection structure diagram must indicate the description of all protective walls that prevent useful radiation beams, including wall thickness, shielding material name and thickness. A3
Protection layer to prevent leakage radiation
The required attenuation Fp of the protection layer to prevent leakage radiation from the source container or shielding is calculated according to formula (4):is the maximum permissible kerma rate (mGy/h) at a distance from the radiation source. A2.2 At a distance ao, the maximum kerma rate K at that point can be calculated by the expected maximum radioactivity A (GB) of the radiation source and the kerma constant Tk (see Table A1) according to formula (2).
Radioactive source
Kerma constant Ik (mGy·m/h·GBg)6oco
The thickness of the protective layer against the useful radiation beam can be found in Figures A1 and A2. By dividing the mass thickness given in Figures A1 and A2 by the density of the shielding material (g/cm), the thickness of the protective layer in cm can be obtained (see A2.4 for details). A2.4 Formula calculation of the protective layer
The thickness d (cm) of the protective layer can also be calculated using the value of the linear attenuation coefficient u in Table A2 according to formula (3), strictly applicable to the linear range of curve F>10 in Figures A1 and A2.
A2.5 The radiation protection structure diagram must indicate the description of all protective walls that prevent useful radiation beams, including wall thickness, shielding material name and thickness. A3
Protection layer to prevent leakage radiation
The required attenuation Fp of the protection layer to prevent leakage radiation from the source container or shielding is calculated according to formula (4):
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.