GB 16368-1996 Radiological health protection standard for instruments containing sealed sources
Some standard content:
National Standard of the People's Republic of China
Radiological protection standards for gauges containing sealed radioactive source1Subject content and scope of application
GB16368-1996
This standard specifies the radiation protection requirements for the production and use of detection instruments (hereinafter referred to as detection instruments) containing sealed radioactive sources (hereinafter referred to as sealed sources).
This standard applies to detection instruments containing sealed sources for intensity measurement. This standard does not apply to detection instruments within the scope of exemption specified in GB13367 "Principles for the exemption management of radiation sources and practices". 2 Reference standards
Classification of sealed radioactive sources
GB4075
General provisions for sealed radioactive sources
GB4076
GB4792
Basic standards for radiation health protection
Radiation protection provisions
GB8703 Vehicles
GB11806 Regulations for the safe transportation of radioactive materials GB13367 Principles for the exemption management of radiation sources and practices GB14052 Radiation safety performance requirements for isotope instruments installed on equipment 3 Terminology
3.1 Source container
A container for placing a sealed source in the correct geometric position and providing adequate shielding protection to keep the surrounding radiation level below the specified value. The source container may also be provided with a source gate for controlling the on and off of the useful beam and a radiation status indicator. 3.2 Useful beam
Radiation through the window, light bar, conical hole or other collimating devices of the source container. 3.3 Sealed source intensity measurement detection instrument An instrument that detects relevant quantities by detecting changes in particle flux in the presence or absence of the object to be measured or detecting the flux of secondary particles generated by the interaction between particles and matter, such as level meters, thickness gauges, density meters, hygrometers, nuclear belt scales, etc. 4 Radiation protection requirements for source containers
4.1 The components used to support and contain sealed sources must be able to firmly and reliably fix the sealed source and facilitate the assembly and disassembly of the sealed source. 4.2 Under different conditions of use, the source container of the detection instrument must comply with the safety performance requirements of GB14052 for the corresponding level of source container leakage dose equivalent rate, the highest and lowest temperatures under normal working conditions, the source gate endurance and fire resistance. 4.3 The source container should have a hidden assembly structure that is not directly visible from the outer surface, or have parts that can only be assembled and disassembled using special dedicated tools.
Approved by the State Administration of Technical Supervision on May 23, 1996, and implemented on December 1, 1996
GB16368-1996
4.4 When the source container is equipped with a beam limiter and a source gate, the following requirements must be met: a. When the detector of the transmission detection instrument is in the use position farthest from the sealed source, the solid angle of the useful beam centered on the sealed source should not exceed the detector without a shield or the shield of the detector, so that the leakage rays passing through the detector or its shield meet the requirements of Table 1.
The source gate should be locked in the position in the "open" and "closed" states, and there should be obvious "open" and "closed" state indications. b.
4.5 Components adjacent to the sealed source should be made of materials with less scattered rays and bremsstrahlung radiation and resistant to radiation from the sealed source. 4.6 The shielding design of the source container for ionizing radiation should comply with the optimization principle, so that the radiation leaking through the outer surface of the source container not only meets the dose limit specified in GB4792, but also reaches "the lowest radiation level that can be reasonably achieved". 4.7 For sealed sources emitting α, low-energy β, and low-energy X-rays, the dose equivalent rate at 5 cm outside the boundary shown in Appendix A (Supplement) should be less than 2.5 μSv/h.
4.8 When the detection instruments other than 4.7 are used in different places, the dose equivalent rates at 5 cm and 100 cm outside the boundary shown in Appendix A (Supplement) should meet the requirements of Table 1.
Table 1 Use places of detection instruments and corresponding leakage radiation control measurement distance. The dose at the following distances outside the boundary
Use places of detection instruments
No restrictions on the range of activities of personnel
Few people stay within 1 m of the source container. No one can enter the area 3 m from the outer surface of the source container, or the radiation workplace has divided the supervision area and non-restricted area
It can only be used in specific radiation workplaces and managed according to the control area, supervision area and non-restricted area
4.9 The outer surface of the source container must have a firm label and clearly indicate the following contents: Ionizing radiation mark in accordance with GB8703; a.
Manufacturer, date of manufacture, product model and serial number; b.
Equivalent rate H control value, μSv/h
2.5≤H<25
25≤H250
250≤H<1 000
Chemical symbol and mass number of the nuclide, activity of the sealed source and date of activity measurement; c.
d. The category and safety performance level code of the detection instrument specified in GB14052. 5 Radiation protection requirements for detection instruments
5.1 The sealed source must comply with the requirements of GB4075 and GB4076. 5.2 The source container must comply with the requirements of Chapter 4. 5.3 When it is necessary to transport the sealed source to the outside of the source container by remote control, the detection instrument should: a. Have an indicator component that prominently displays the working status of the sealed source on the console and source container; b. Be equipped with a dose instrument to monitor the working status of the sealed source. 5.4 The random documents of the detection instrument must include: 100cm
0. 25≤H<2. 5
2.5≤H<25
25≤H<100
The documents of the technical characteristics of the detection instrument shall list the contents and technical data related to 4.2 and 4.6 to 4.9; a.
b. The radiation protection inspection certificate of the detection instrument; C. The radiation protection precautions for the installation, disassembly, maintenance, transportation, storage and decommissioning of sealed sources and source containers, prevention of radiation accidents, emergency response to abnormal events, registration of the use license of the detection instrument, etc.; d. The curve or graph or table corresponding to the dose equivalent rate of 2.5μSv/h when the detection instrument is in working state. 174
6 Radiation protection requirements for production and use of testing instruments 6.1 Selection of sealed sources
GB16368-1996
Under the condition of meeting the measurement requirements, sealed sources with low activity, weak penetration and low radiotoxicity should be selected. 6.2 Storage requirements
Storage of sealed sources and source containers containing sealed sources and temporary storage of source containers containing sealed sources during installation and maintenance of testing instruments should meet the following requirements at the same time:
Anti-theft storage conditions and management measures; a.
b. Shielding protection measures should be taken to ensure that the dose equivalent rate at any position that non-radiation workers may reach is less than 2.5uSv/h; a conspicuous "ionizing radiation" sign should be set at the storage place. c.
6.3 Transportation requirements
The transportation of sealed sources and source containers containing sealed sources must comply with GB11806.6.4 Production requirements
In the following cases, type tests should be carried out according to the radiation protection inspection items specified in Article 7.1: a.
Before new products are put into production;
Products in continuous production should be tested not less than once every two years; when they are put into production again after an interval of more than one year;
When there are major changes in design, process or materials. d.
6.5 Usage requirements
6.5.1 Newly purchased testing instruments must be inspected for radiation protection in accordance with this standard. 6.5.2 At the installation site of the testing instrument, the source container must be installed firmly and reliably, measures must be taken to prevent the loss of the sealed source, and personnel must be restricted from entering the useful wiring harness area between the source container and the object under test. 6.5.3 When it comes to the installation, inspection and maintenance of sealed sources, operators must be familiar with the structure of the source container, master radiation protection skills, and obtain radiation work qualifications.
6.5.4 Decommissioned sealed sources must be strictly managed as radioactive hazardous materials, or returned to the manufacturer or transferred to the decommissioned source storage department, and there must be permanent files.
7 Inspection
7.1 Inspection items
The requirements for the inspection items of the radiation protection performance of the detection instrument are listed in Table 2. Table 2
Requirements for the inspection items of the radiation protection performance of the detection instrument Item
Structure and working
Status indication
Source gate endurance
The highest and lowest temperatures applicable to the source container
Fire resistance of the source container
Signage of the source container
Random documents of the instrument
Clause number
4. 1;4. 3~~4.5
Before production
Type inspection
After production
Cycle operation 10 times
6. 4 d test
6.4d test
Factory inspection, user
acceptance by management department
Visual inspection
Cycle operation 10 times
User and management
inspection by management
Visual inspection
Source container installation location
When the sealed source is in the storage position
Leakage radiation of the source container
When the sealed source is in the working position
Leakage radiation of the source container and
2.5μSv/h dose area
Clause number
6.5.4;6.5.5
GB16368-1996
Continued table 2
Type inspection
Before production
Note: "" in the table indicates that inspection is required, and "×\" indicates that inspection is not required. 7.2 Test and evaluation methods for source containers
After production
Factory inspection, user
and acceptance by management departments
7.2.1 The applicable temperature range, fire resistance test and source gate endurance test of the source container shall be carried out in accordance with GB14052. 7.2.2 After the applicable temperature and source gate endurance tests of the source container, the following conditions must be met: a.
The safety mechanism and other relevant components of the source container can still operate normally, and the signs and instructions are still clear; the dose equivalent rate around the source container is not greater than 1.5 times that before the experiment. 7.2. 3 After the fire resistance test of the source container, the following conditions must be met: a.
In any direction, the dose equivalent rate at 1m away from the outer surface of the source container is less than 10mSv/h; the sealed source is still in the source container;
The total surface contamination of the internal components of the source container is less than 2kBq. 7.3 Instruments and methods for measuring leakage rays
7.3.1 The measuring instrument shall be suitable for the radiation type, energy and radiation level of the rays to be measured. Verification by users and management
department
7.3.2 During the type test, the activity of the sealed source in the source container shall be the rated activity value. When the activity of the sealed source is lower than the rated activity, the test result shall be multiplied by the coefficient K.
Rated activity of sealed source| |tt||Activity of sealed source during inspection
7.3.3 When the sealed source is in the storage position (source gate closed), the detection points of the radiation leakage from the source container are as follows: a. With the sealed source as the origin of coordinates, the useful beam center axis direction is the B axis, perpendicular to the Z axis plane, any mutually perpendicular X and Y axes. In the positive and negative directions of the X, Y, and Z axes, the detection is carried out at the positions 5 cm and 100 cm away from the surface of the source container. b. For transmission instruments where the source container and the detector are located on both sides of the object to be tested, when the distance between the adjacent surfaces of the source container and the detector on the useful beam axis is less than or equal to 10 cm, it is not necessary to measure in the area between the two. When the distance is greater than 10 cm, measurement must be carried out (see Appendix A Figure A6).
7.3.4 When the sealed source is in the working position (source gate open), the detection of radiation leakage outside the source container should be: a. For transmission instruments, the detection should be carried out without the object to be tested; b. For scattering instruments, the detection should be carried out with the object to be tested. The detection points should include: the positions shown in Appendix A; positions where higher doses are expected; positions where personnel stay for a long time, etc. 7.3.5 For detection at 5 cm outside the boundary described in 4.7, the recorded reading value shall be the average reading value over an area of 10 cm2. For detection at 100 cm outside the boundary, the recorded reading value shall be the average reading value over an area of 100 cm2. The distance between the detection point and the boundary shall be measured by the center position of the detector of the protective dose measurement instrument. For instruments containing neutron sources, detection at 5 cm outside the boundary described in 4.7 can be approximated by placing the probe of the neutron protective dose instrument close to the boundary position. 176
GB16368-1996
Appendix A
Schematic diagram of the dose equivalent measurement area outside the source container (supplement)
Schematic diagram of the dose equivalent measurement area outside the source container of the measuring instrument. A1
Unit: cm
Source component
Schematic diagram of the dose equivalent rate measurement area around the source container of the density meterUnit: cm
Measuring head not at the optimal distance
1.3 cm thick steel screen, its width and height should be at least 5 cm larger than the beam cutting surface size2
Figure A2 Schematic diagram of the dose equivalent rate measurement area around the source container of the material level meter177
Roller-shaped simulant
GB 16368—1996
Unit: cm
Measuring head
Schematic diagram of the dose equivalent rate measurement area around the β and backscatter measuring instrumentsFigure A3
Unit: cm
Measuring head
Measured material
Figure A4 Schematic diagram of the dose equivalent rate measurement area around the surface backscatter measuring instrument100
GB 16368--1996
Measuring head
-0.6 cm thick steel plate
Unit: cm
Standard scatterer, the size of which should be at least 5 cm larger than the cross-sectional size of the useful
beam
2 cm thick polyethylene
Figure A5 Schematic diagram of the dose equivalent rate measurement area around the backscattered neutron measuring instrument A2 The distance between the probe of the transmission measuring instrument and the adjacent surface of the source container is less than or equal to or When it is greater than 10cm, when the source gate is in the "open" or "closed" state, the schematic diagram of the equidistant contour lines of the dose equivalent rate measurement area outside the source container is shown in Figure A6. 179
Source components
Additional notes:
GB16368
Source closed
Source components
Source gate in the "open position"
Figure A6 Schematic diagram of equidistant contour lines
This standard is proposed by the Ministry of Health of the People's Republic of China. This standard was drafted by the Beijing Institute of Radiation Health and Protection. The main drafter of this standard is Wang Shijin.
This standard is interpreted by the Ministry of Health's Industrial Hygiene Laboratory, the technical management unit entrusted by the Ministry of Health. 180
Unit: cm3 When the sealed source is in the storage position (source gate closed), the source container leakage detection points are as follows: a. With the sealed source as the coordinate origin, the useful beam center axis direction is the B axis, and the X and Y axes perpendicular to each other in the Z axis plane are randomly selected. In the positive and negative directions of the X, Y, and Z axes, the detection is carried out at the positions 5 cm and 100 cm away from the surface of the source container. b. For transmission instruments where the source container and the detector are located on both sides of the object to be tested, when the distance between the adjacent surfaces of the source container and the detector on the useful beam axis is less than or equal to 10 cm, it is not necessary to measure in the area between the two. When the distance is greater than 10 cm, measurement must be carried out (see Appendix A Figure A6).
7.3.4 When the sealed source is in the working position (source gate open), the detection of radiation leakage outside the source container should be: a. For transmission instruments, the detection is carried out without the object to be tested; b. For scattering instruments, the detection is carried out with the object to be tested. The detection points should include: the positions shown in Appendix A; the positions where the expected dose is high; the positions where the personnel stay for a long time, etc. 7.3.5 For detection at 5 cm outside the boundary described in 4.7, the recorded reading value shall be the average reading value over an area of 10 cm2. For detection at 100 cm outside the boundary, the recorded reading value shall be the average reading value over an area of 100 cm2. The distance between the detection point and the boundary shall be measured with respect to the center position of the detector of the protective dose measuring instrument. For instruments containing neutron sources, detection at 5 cm outside the boundary described in 4.7 can be approximated by placing the probe of the neutron protective dose instrument close to the boundary position. 176
GB16368-1996
Appendix A
Schematic diagram of the dose equivalent measurement area outside the source container (supplement)
Schematic diagram of the dose equivalent measurement area outside the source container of the measuring instrument. A1
Unit: cm
Source component
Schematic diagram of the dose equivalent rate measurement area around the source container of the density meterUnit: cm
Measuring head not at the optimal distance
1.3 cm thick steel screen, its width and height should be at least 5 cm larger than the beam cutting surface size2
Figure A2 Schematic diagram of the dose equivalent rate measurement area around the source container of the material level meter177
Roller-shaped simulant
GB 16368—1996
Unit: cm
Measuring head
Schematic diagram of the dose equivalent rate measurement area around the β and backscatter measuring instrumentsFigure A3
Unit: cm
Measuring head
Measured material
Figure A4 Schematic diagram of the dose equivalent rate measurement area around the surface backscatter measuring instrument100Www.bzxZ.net
GB 16368--1996
Measuring head
-0.6 cm thick steel plate
Unit: cm
Standard scatterer, the size of which should be at least 5 cm larger than the cross-sectional size of the useful
beam
2 cm thick polyethylene
Figure A5 Schematic diagram of the dose equivalent rate measurement area around the backscattered neutron measuring instrument A2 The distance between the probe of the transmission measuring instrument and the adjacent surface of the source container is less than or equal to or When it is greater than 10cm, when the source gate is in the "open" or "closed" state, the schematic diagram of the equidistant contour lines of the dose equivalent rate measurement area outside the source container is shown in Figure A6. 179
Source components
Additional notes:
GB16368
Source closed
Source components
Source gate in the "open position"
Figure A6 Schematic diagram of equidistant contour lines
This standard is proposed by the Ministry of Health of the People's Republic of China. This standard was drafted by the Beijing Institute of Radiation Health and Protection. The main drafter of this standard is Wang Shijin.
This standard is interpreted by the Ministry of Health's Industrial Hygiene Laboratory, the technical management unit entrusted by the Ministry of Health. 180
Unit: cm3 When the sealed source is in the storage position (source gate closed), the source container leakage detection points are as follows: a. With the sealed source as the coordinate origin, the useful beam center axis direction is the B axis, and the X and Y axes perpendicular to each other in the Z axis plane are randomly selected. In the positive and negative directions of the X, Y, and Z axes, the detection is carried out at the positions 5 cm and 100 cm away from the surface of the source container. b. For transmission instruments where the source container and the detector are located on both sides of the object to be tested, when the distance between the adjacent surfaces of the source container and the detector on the useful beam axis is less than or equal to 10 cm, it is not necessary to measure in the area between the two. When the distance is greater than 10 cm, measurement must be carried out (see Appendix A Figure A6).
7.3.4 When the sealed source is in the working position (source gate open), the detection of radiation leakage outside the source container should be: a. For transmission instruments, the detection is carried out without the object to be tested; b. For scattering instruments, the detection is carried out with the object to be tested. The detection points should include: the positions shown in Appendix A; the positions where the expected dose is high; the positions where the personnel stay for a long time, etc. 7.3.5 For detection at 5 cm outside the boundary described in 4.7, the recorded reading value shall be the average reading value over an area of 10 cm2. For detection at 100 cm outside the boundary, the recorded reading value shall be the average reading value over an area of 100 cm2. The distance between the detection point and the boundary shall be measured with respect to the center position of the detector of the protective dose measuring instrument. For instruments containing neutron sources, detection at 5 cm outside the boundary described in 4.7 can be approximated by placing the probe of the neutron protective dose instrument close to the boundary position. 176
GB16368-1996
Appendix A
Schematic diagram of the dose equivalent measurement area outside the source container (supplement)
Schematic diagram of the dose equivalent measurement area outside the source container of the measuring instrument. A1
Unit: cm
Source component
Schematic diagram of the dose equivalent rate measurement area around the source container of the density meterUnit: cm
Measuring head not at the optimal distance
1.3 cm thick steel screen, its width and height should be at least 5 cm larger than the beam cutting surface size2
Figure A2 Schematic diagram of the dose equivalent rate measurement area around the source container of the material level meter177
Roller-shaped simulant
GB 16368—1996
Unit: cm
Measuring head
Schematic diagram of the dose equivalent rate measurement area around the β and backscatter measuring instrumentsFigure A3
Unit: cm
Measuring head
Measured material
Figure A4 Schematic diagram of the dose equivalent rate measurement area around the surface backscatter measuring instrument100
GB 16368--1996
Measuring head
-0.6 cm thick steel plate
Unit: cm
Standard scatterer, the size of which should be at least 5 cm larger than the cross-sectional size of the useful
beam
2 cm thick polyethylene
Figure A5 Schematic diagram of the dose equivalent rate measurement area around the backscattered neutron measuring instrument A2 The distance between the probe of the transmission measuring instrument and the adjacent surface of the source container is less than or equal to or When it is greater than 10cm, when the source gate is in the "open" or "closed" state, the schematic diagram of the equidistant contour lines of the dose equivalent rate measurement area outside the source container is shown in Figure A6. 179
Source components
Additional notes:
GB16368
Source closed
Source components
Source gate in the "open position"
Figure A6 Schematic diagram of equidistant contour lines
This standard is proposed by the Ministry of Health of the People's Republic of China. This standard was drafted by the Beijing Institute of Radiation Health and Protection. The main drafter of this standard is Wang Shijin.
This standard is interpreted by the Ministry of Health's Industrial Hygiene Laboratory, the technical management unit entrusted by the Ministry of Health. 180
Unit: cm
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.