Some standard content:
GB15849—1995
This standard is equivalent to the first edition of the international standard ISO9978-1992. In 1979, the International Organization for Standardization had stipulated the leakage inspection method of sealed radioactive sources in the technical report ISO/TR4826-1979. At that time, it was not published as an international standard due to insufficient experiments. After 13 years of experience summary, the technical report was revised into an international standard, namely IS09978--1992. Compared with the original technical report, it not only supplements some contents, but also modifies the detection threshold and limit of some inspection methods. It is a relatively complete and applicable international standard for inspecting sealed radioactive sources. At present, sealed radioactive sources have been widely used in various fields such as industry, agriculture, medicine, and scientific research. The safety issues of sealed radioactive sources have aroused widespread concern from all walks of life. Therefore, it has become a top priority to formulate a national standard. After domestic experts studied and demonstrated IS09978-1992, they believed that this international standard is completely applicable to the leakage inspection of sealed radioactive sources in my country, so this international standard was converted into my country's national standard.
This standard shall be implemented from August 1, 1995. From the date of entry into force, Appendix E of GB4075-83 shall be invalidated. Appendix A of this standard is a standard-promoting appendix.
Appendix B of this standard is a reminder appendix. This standard was proposed by the National Nuclear Energy Standardization Technical Committee. The drafting unit of this standard: Nuclear Industry Standardization Research Institute. The main drafters of this standard: Mi Peiqing, Wang Lingqi. 387
In view of the increasing use of sealed radioactive sources, it is necessary to formulate some standards to guide users, manufacturers and management agencies. When formulating these standards, radiation protection should be considered first. The leakage inspection method for sealed radioactive sources was published in ISO/TR4826\, and the experience accumulated since then has helped the international standard to be improved day by day.
1)ISO)/TR 4826
Leakage test methods for sealed radioactive sources
1 Scope
National Standard of the People's Republic of China
, Leakage test methods for sealed radioactive sources
Sealed radioactive sources
Leakage test methods
GB 15849—1995
eqv 1sO 9978-- -1992
This standard specifies different leakage test methods for sealed radioactive sources and establishes a set of comprehensive test procedures using radioactive and non-radioactive methods.
This standard applies to the following types of control:
a) Quality control for the validation of the tests required to determine the classification when classifying prototype sealed radioactive sources in accordance with GB4075;
b) Production control of various sealed radioactive sources; () Periodic inspection of sealed radioactive sources at specified time intervals during their effective use. Appendix A of this standard (Annex to the standard) provides suggestions to guide users to select the most appropriate inspection method according to the type of control and the type of sealed radioactive source.
This standard does not provide for special circumstances that require special inspection. In addition to complying with this standard, the production, use, storage and transportation of sealed radioactive sources shall also comply with the requirements of relevant laws and regulations of my country. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When the standard is published, the versions shown are effective. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB4075-1983 Classification of sealed radioactive sources
3 Definitions
This standard adopts the following definitions.
3.1 Sealed radioactive source sealed radioactive source is a radioactive material permanently sealed in one or more layers of cladding and (or) tightly combined with a certain material. Under the designed conditions of use and normal wear, this cladding and (or) material must be sufficient to maintain the sealing of the sealed source. Note: For the sake of simplicity, the term "sealed source" is used instead of "sealed radioactive source" in this standard. 3.2 Leaktight
A sealed source can meet the limits specified in Table 1 after undergoing a leak test. 3.3 Capsule
A protective shell that prevents the leakage of radioactive material, usually made of metal. 3.4 Dummy sealed source A replica of a sealed source, the structure and material of its shell are exactly the same as those of the sealed source it represents, but the radioactive material in the source core is replaced by a non-radioactive material with physical and chemical properties as similar as possible. Approved by the State Administration of Technical Supervision on December 13, 1995 and implemented on August 1, 1996
GB 15849-1995
3.5 Simulated sealed source A replica of a sealed source whose shell structure and materials are exactly the same as those of the sealed source it represents, but the radioactive material in the source core is replaced by a radioactive material with physical and chemical properties as similar as possible and containing only tracer amounts. Note: The tracer amount of radioactive material must be soluble in a solvent that does not corrode the source shell, and the maximum activity should be equivalent to the activity used in the sealed shell. 3.6 Model designation
A description item or reference number used to identify the design of a specific sealed source. 3.7 Prototype sealed source The original sample of a sealed source, which is the model for manufacturing all sealed sources marked with the same model mark. 3.8 Quality control
Control of the prototype sealed source to ensure that the sealed source meets the quality requirements of GB4075. 3.9 Production control Performance inspection of a sealed source with a new model number before it is put into actual manufacture and use. 3.10 Recurrent inspections Special control of a sealed source at regular intervals to determine the sealing performance of the sealed source during storage and use. 3.11 Leakage Migration of radioactive material from a sealed source to the environment. 3.12 Non-leachable Radioactive material encapsulated in a sealed source is insoluble in water and cannot be converted into diffusible products. 3.13 Standard helium leakage rate Nitrogen leakage rate at a temperature of 23 ± 7, an inlet pressure of 10° ± 5 × 103 Pa, and an outlet pressure of no more than 10° Pa. The unit is μPa·m\.s-1.1μPa·m\.s----10-*Pa.m\.s-1-10-\atm.cm\.s\. 4 Requirements
The inspections mentioned in this standard must be carried out by qualified personnel who are competent and have received radiation protection training. Depending on the type of control and the type of sealed source, at least one of the inspection methods described in Chapters 5 and 6 shall be selected for inspection. The selection of inspection methods is shown in Appendix A (Appendix to the standard). When performing special inspections not specified in this standard, the user shall be able to demonstrate that the method used is at least as effective as the corresponding method specified in this standard.
When more than one leak test is performed on a sealed source, a final wipe test is usually performed for contamination inspection. At the end of the inspection, if the sealed source meets the limits specified in Table 1, it is confirmed that it is sealed. If the measurement levels of different methods are not exactly the same, the results will depend on the measuring equipment and procedures. In most cases, when the leakage rate of non-leachable solid contents is 10μPa·m·s-1 and the leakage rate of leachable solid, liquid and gaseous contents is 0.1uPa·m·s-1, it can be considered to be equivalent to the radioactivity release limit of 2KBq (~50nCi). Regardless of the nature of the contents, in dry air at a temperature of 25C, when the relative vacuum is equal to or lower than 10°Pa and the internal and external pressure difference is 105Pa, a leakage rate equal to or greater than 10-2μPa·m3·s- indicates that it is not sealed. In addition to regular inspections, the sealed source must be thoroughly cleaned and carefully visually inspected before any inspection. All equipment used in the inspection must be properly maintained and calibrated regularly. At the inspection site, the following parameters should be specified as much as possible for any inspection: - pressure;
temperature;
- the proportionality factor between the volume of the sealed source and the volume of the leak detection chamber used for certain leak inspections and the volume of the liquid used to submerge the sealed source being inspected.
The wiping test should not be used as a leak test method in general. It is only used when certain special types of sources (e.g., thin window sources) are to be inspected periodically and when there is no other more appropriate test method. Table 1 Detection thresholds and limits of different test methods Test method
Hot liquid immersion test
Boiling liquid bubbling test
Liquid flash drying liquid no bubble test
Emission test
Liquid scintillation emission test
Wet wipe test
Dry wipe test
Nitrogen test
Nitrogen pressurization test
Vacuum bubbling test
Hot liquid bubbling test
Gas pressurized bubbling test
Liquid ammonia bubbling test
Water pressurization test
1) Not applicable.
Bar number
5, 1,3
Detection limit
Non-exudable contents
10～1
0. 4-0. 004
10～1
10-2-10-
1~10-2
2) These detection limit instruments are suitable for single leaks under good observation conditions. 3) Not sensitive enough.
Diffusible content or gas content
0. 2(twRn/12 h)
0. 2(*Rn/12 h)
Standard nitrogen inflow rate uPa·m
Increase in mass of water+
Under normal circumstances, before the final measurement with a more accurate calibrated device, the wipe test or liquid diffusion test sample should be immediately checked with a common active pollution measuring device (such as a Geiger counter) to determine whether there is obvious contamination. The reference materials of this standard are listed in Appendix B (Suggested Appendix), which fully considers the coordination and consistency of the standard content with related standards. 5 Radioactive test method
5.1 Immersion test
5.1.1 Hot liquid immersion test
Immerse the sealed source in a liquid that will not corrode the surface material of the source and can effectively remove all traces of radioactive substances that have leaked out under such test conditions (such liquids include distilled water, dilute detergent solution or integrator, 5% slightly acidic solution or slightly alkaline solution). Heat the liquid to 50±5°C and soak the source at this temperature for more than 4 hours. Take out the sealed source and measure the radioactive activity of the liquid. Note: Ultrasonic cleaning can also be used. When using this method, the immersion time of the sealed source in the liquid at 70±5°C can be reduced to about 30 minutes. 5.1.2 Boiling liquid immersion test
GB15849—1995
Immerse the sealed source in a liquid that does not corrode the surface material of the source and can effectively remove all traces of radioactive substances leaked out under such test conditions, boil for 10 minutes, let it cool, and then clean the sealed source with fresh immersion liquid. Immerse the sealed source in a fresh immersion liquid again, boil for 10 minutes, take out the sealed source, and measure the radioactivity of the liquid. 5.1.3 Liquid scintillator immersion test
At room temperature, immerse the sealed source in liquid scintillator that does not corrode the surface material of the source for at least 3 hours. Store away from light to prevent photoluminescence. Take out the sealed source and measure the radioactivity of the liquid by liquid scintillation counting method. 5.1.4 Warm immersion test!
Immerse the sealed source in a liquid that does not corrode the surface material of the source and can effectively remove all traces of radioactive substances leaked out under such test conditions at 20±5°C for 24 hours. Take out the sealed source and measure the radioactivity of the liquid. 5.1.5 Criteria for judging the qualified test
If the measured radioactivity does not exceed 0.2kBq (5nCi), the source is judged to be sealed. 5.2 Emission test
5.2.1 Emission test - absorption method (applicable to radium-226 sealed source) Place the sealed source in a small airtight container with some suitable absorbent, such as activated carbon, cotton or polyethylene, and leave it for more than 3 hours. Quickly take out the sealed source and close the container, and immediately measure the radioactivity on the absorbent. 5.2.2 Liquid scintillation immersion emitting test method (applicable to radium-266 sealed source) Follow the steps described in 5.1.3.
5.2.3 Emission test method (applicable to krypton-85 sealed source) Place the sealed source under reduced pressure for 24 hours. Measure the krypton-85 content in the sealed chamber by plastic scintillation counting method. Repeat the test after 7 days.
5.2.4 Other radiometric test methods
Any other test methods equivalent to those in 5.2.1 to 5.2.3 may be used. 5.2.5 Criteria for determining qualified tests
When the tests in 5.2.1 and 5.2.2 are completed, if the radioactivity of the hydrogen collected in 12 hours does not exceed 0.2 kBq (~5 nCi), the source is determined to be sealed. When the test cycle is less than 12 hours, corresponding corrections must be made. When the tests in 5.2.3 and 5.2.4 are completed, if the measured radioactivity does not exceed 4 kBq/24h (~100 nCi/24h): the source is determined to be sealed.
5.3 Wipe test
If the wipe test is used to check the sealing of the source after the mechanical or heated prototype test, the sealed source to be tested must be cleaned (decontaminated) before the test.
When wiping test is used as a means of leak testing during the manufacturing stage, the sealed source must be cleaned first before the test and should be stored for observation for 7 days.
5.3.1 Wet wiping test
Use filter paper or other suitable highly hygroscopic materials to make a broom, wet it with a liquid that does not corrode the surface material of the source, and the liquid used under such test conditions must be able to effectively remove any radioactive material on the surface of the source. Use the broom to thoroughly wipe all the outer surfaces of the sealed source and measure the radioactivity of the broom. 5.3.2 Dry wiping test
For places where wet wiping brooms are not suitable, for example, for the inspection of high-activity cobalt-60 sources or regular inspections of certain sources, dry wiping test can be used.
For this test, first use a dry filter paper broom to thoroughly wipe all the outer surfaces of the sealed source, and then measure the radioactivity of the wipe. 1) This test may be useful for places where there is no hot liquid test method. However, it is recommended to use the hot liquid test method when possible because it has been widely used for many years and is very effective. 392
5.3.3 Criteria for judging whether the test is qualified
GB15849-1995
If the measured radioactivity does not exceed 0.2kBq (~5nCi), the source is judged to be sealed. Note: For accessible surfaces, the key point of using wipe tests is to get as close to the sealed source as possible, and attention should be paid to radiation protection. 6 Non-radioactive test methods
When non-radioactive test procedures are used, the relationship between the volume leakage rate and the amount of radioactive material lost should be determined. In practice, it is difficult to determine this relationship because the forms of radioactive materials used in sealed sources are diverse and the types of leakage are also different.
The relationship between the volume leakage rate and the amount of radioactive material loss given in this standard is derived from data published in the International Atomic Energy Agency documents. Although it has not been fully confirmed by experimental work, the volume leakage test method has been used for many years, and experience shows that these effective test methods are acceptable.
Before testing in accordance with 6.1 to 6.3, the sealed source should first be thoroughly cleaned and completely dried. For sealed sources with leachable or gaseous contents, the ammonia test in 6.1 can be used. It must be ensured that the test method does not have serious deficiencies that may invalidate the test results, such as visual inspection, or methods with less sensitivity than the tests described in this standard. In addition to the tests described in 6.3, for the test to be effective, the free space in the sealed source must be less than 0.1crm\. If this test is used for free space less than 0.For sealed sources with a volume of 1 cm2, the user must be able to prove that this test is effective. For sealed sources with leachable or gaseous contents, only the nitrogen test with a low detection limit (6.1) can be used. 6.1 Nitrogen mass spectrometer leak test
6.1.1 Nitrogen test
Place the sealed source filled with nitrogen in a suitable vacuum chamber and then evacuate it with an ammonia mass spectrometer. Estimate the actual nitrogen leakage rate according to the method recommended by the manufacturer of the leak test equipment. It must be ensured that the concentration of industrial-grade nitrogen filled in the sealed source is greater than 5%. Divide the indicated nitrogen leakage rate estimated above by the ammonia concentration in the free space to obtain the actual standard nitrogen leakage rate. 6.1.2 Nitrogen pressurization test
Place the sealed source in a pressurized chamber and purge the air in the chamber with nitrogen. Pressurize the chamber to the specified ammonia pressure and maintain the pressure for the specified time. Depressurize the gas chamber, flush the sealed source with dry ammonia or clean it with volatile fluorinated hydrocarbon liquid, transfer the source to a suitable vacuum chamber, and measure the ammonia leakage rate according to the procedure in 6.1.1. Calculate the indicated nitrogen leakage rate Q and the actual standard ammonia leakage rate L according to the following formula: Q=P
Wu Zhong: Q-indicated ammonia leakage rate, μPa·m2·sl, l---actual standard leakage rate within the range of l μPam2·s-1～10-2μPa·m·s-1, μPa·m·s\ (L≤1.7 VQV/Pt);
P. ———standard atmospheric pressure, μPa,P. =1.01325×105μPa; P-ammonia pressure, μPa,
—pressurization time, s;
Vfree space in the source, m\.
Note 1: If the hydrogen pressure is P, in MPa (the actual nitrogen pressure is between 0.5MPa and 10MPa), the pressure P is maintained at a certain specified time 1 in hours, and the delay time between pressurization and measurement is less than 10min. In addition, considering that the free space V (in cubic centimeters) in the sealed source is greater than 0.1cm, a simple test parameter can be selected and the test result can be calculated using the following formula: 393
GB15849-1995
Q= 0. 35×
Note 2: In the case of partial flow through a single hole or multiple holes, formula (2) is valid. In the case of high percentage viscous laminar flow, this formula will lead to a slightly higher result of the actual standard ammonia leakage rate, and this factor has little effect on the test result. 6.1.3 Criteria for passing the test
When these tests are completed, the source is considered to be sealed if the actual standard ammonia leakage rate is less than 1 μPa·m\·s\\ for non-leachable contents and less than 10-2 μPa·m·s-\ for leachable or gaseous contents (see Table 1). 6.2 Bubble Leak Test
The bubble leak test relies on increasing the internal pressure and the subsequent leakage of gas from the internal pores to form a few visible bubbles in the liquid bath. For a particular leak, the bubble rate increases as the surface tension of the liquid decreases. 6.2.1 Vacuum Bubble Test
In a vacuum chamber of appropriate size, place ethylene glycol, isopropyl alcohol, mineral oil (or silicone oil) or water with a wetting agent as the leak test liquid. Evacuate the vacuum chamber for more than 1 minute to reduce the air content in the liquid. Return to normal pressure and completely immerse the sealed source in the liquid so that the top of the source is at least 5 cm below the liquid surface. Then reduce the absolute pressure in the vacuum chamber to between 15 and 25 kPa. Observe for more than 1 minute to see if there are any bubbles escaping from the sealed source. 6.2.2 Hot liquid bubbling test
Before the test, ensure that the sealed source is at room temperature. Place the sealed source at room temperature in a water bath of 90 to 95°C, with the top of the source at least 5 cm below the water surface. Glycerol at 120 to 150°C can also be used instead of water. Observe for more than 1 minute to see if there are any bubbles escaping from the sealed source. If possible, it is best to observe for more than 2 minutes, especially when the heat capacity of the source shell is large and the thermal conductivity is poor, it must be observed for more than 2 minutes.
6.2.3 Gas pressure bubbling test
Place the sealed source in a suitable pressure chamber, the space of which is at least twice the volume of the source and five times the volume of the free space in the source. Fill the pressure chamber with ammonia until the pressure is above 1MPa and maintain for 15 minutes. Rapidly release the pressure, take out the sealed source, and immediately soak it in ethylene glycol, isoflurane, acetone or water containing a wetting agent, so that the top of the source is at least 5 cm below the liquid surface. Observe for more than 1 minute to see if there are bubbles escaping from the sealed source.
6.2.4 Liquid nitrogen bubbling test
Immerse the sealed source completely in liquid nitrogen for about 5 minutes, then immediately transfer it to the test liquid (usually methanol) and observe for more than 1 minute to see if there are bubbles escaping from the sealed source. 6.2.5 Criteria for judging qualified tests
After completing the tests described in 6.2.1 to 6.2.4, if no bubbles are seen, it can be concluded that the leakage rate of the sealed source is less than 1uPa·m3·s1. If the contents cannot be leaked, it can be determined that the source is sealed. 6.3 Water pressure test
First accurately weigh the mass of the sealed source on a balance, then perform an experimental pressure test with water, wipe the sealed source, and then accurately weigh the mass of the source with the same balance.
If the increase in mass is less than 50ug, the contents of the sealed source are not leached, and the source can be determined to be sealed. This test is valid only when the amount of water contained in the calculated free space in the sealed source is more than 5 times greater than the sensitivity of the balance. This test is particularly suitable for evaluating external pressure tests of levels 3, 4, 5, and 6 in GB4075. 394
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Appendix A
(Standard Appendix)
Guide to the selection of test methods according to the type of control and the type of sealed source This appendix gives guidance on the selection of the most appropriate test method according to the type of sealed source (design and characteristics, etc.) for quality control, production control and periodic inspection.
Although the content of Table A1 is not very comprehensive, it covers a wide range and can serve as a guide for the design of many sealed sources. Table A1 lists the preferred and secondary inspection methods. A1 Leakage inspection for sealed source production
For the production of sealed sources containing radioactive nuclides, the most appropriate leakage inspection method can be selected from Table A1 according to the design and process of various sealed sources.
A2 Leakage inspection for prototype sealed sources
In order to make the graded inspection of prototype sealed sources determined in accordance with GB4075 effective, leakage inspection can be carried out according to the following types of sources:
a) prototype sealed source with nominal radioactive content; b) simulated sealed source;
c) dummy sealed source.
Obviously, the last type of sealed source must use a non-radioactive leakage inspection method. According to the process and design of the sealed source, the most appropriate leakage inspection method can be selected from Table A1. A3 Periodic Inspection
After the sealed sources are delivered from the manufacturer, they need to be inspected at regular intervals to check whether they have leaks. The inspection cycle varies with the type, design and working environment of the sealed sources. These inspection methods do not need to be the same as those used for the production of sealed sources. It is important to consider the environment in which the sealed source is used and the various hazards it may be exposed to during its effective use period. In fact, when considering the periodic inspection of sealed sources, the following situations may be encountered: a) The sealed source can only be inspected on site, and only a swab inspection can be used for the most accessible parts. In this case, the swab inspection (5.3) is selected. If possible, the sealed source should also be visually inspected. Table A1 Selection of leak test methods related to manufacturing process Tests used for production sources
Type of source
A Sealed source containing radioactive material
A1 Single-layer thin window source
For example, smoke detector
A2 Low-activity standard source
For example, source encapsulated in plastic
Bubbling (5.1)
Wipe (5.3)
Determining the classification of sources Tests used
Immersing (5.1)
Wipe (5.3)
Type of source
GB 15849-1995
Continued Table A1
Tests for use of production sources
A3 Metrology, single or double sealed sources for radiography and close-range radiation therapy (except 3H and 226Ra)
A4 Single or double sealed radium 226 and other gas sources A5 Double sealed sources and high-activity irradiation sources for teletherapy
BA3, A4 and A5 type simulated sealed sources
C dummy sealed sources
Immersion (5.1)
Ammonia test (6.1)
Emission test (5.2)
Ammonia test (6.1)
Bubbling (6.2)
Immerse (5.1)
Immerse (5.1)
Tests for determining source classification use
Immerse (5.1)
Ammonia test (6.1)
Emit gas test (5.2)bzxz.net
Immerse (5.1)
Wipe (5.3.2)Ammonia test (6.1)
Immerse (5.1)
Ammonia test ( 6.1)
Ammonia test (6.1)
Bubbling (6.2)
Immersing (5.1)
Bubbling (6.2)
Bubbling (6.2)
Bubbling (6.2)
b) Sealed sources can only be tested on site where they are used and where direct contact with the source is not possible or desirable because the operator would be exposed to excessive radiation doses. For example, high-activity teletherapy sources or other sources in sealed containers. In this case, the most accessible part of the source should be swabbed. It should be noted that if the test reveals the presence of radioactivity, even if it is below the 0.2 kBq (5 nCi) limit, measures should be taken to determine whether it is caused by leakage of the source. In this case, repeated tests should be carried out at regular intervals to determine whether the measured radioactivity is increasing.
c) In some units (e.g., hospitals), when there are conditions for inspecting sealed sources by methods other than swabbing, or when the sources are shipped back to the manufacturer or other appropriate laboratories for inspection, the inspection methods recommended for production sealed sources in Table A1 may be used. If possible, a visual inspection of the sealed source should also be performed.
Special attention should be paid to the need to ensure that the radiation exposure level is controlled within acceptable limits when periodic inspections are performed. Appendix B
(Reminder Appendix)
References
(1) McMASRERS, RC, ed., Non-destructive Testing Handbook, Vol. 1, Leak Testing, American Society for Non-destructive Testing American Society for Metals, 2nd ed. ,1982. Non-destructive Testing Handbook, Vol. 1, Leak Testing, American Society for Non-destructive Testing/American Society for Metals, 2nd ed. ,1982. (2) American National Standard for Radioactive Materials, Leakage Tests on Packages for Shipment, ANSI No. 14.5-1987. (3) ASTM E 515-74 (Reapproved 1980), Standard Method of Testing for leaks Using Bubble Emis-sion Techniques. (4) ASTM F 98-72 (Reapproved 1977), Standard Recommended Practices for Determining Hermeticity of Electron Devices by a Bubble Test. 396
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(5) ASTM F 134-78, Standard Recommended Practices for Determing Hermeticity of electron deviceswith a Halium Mass Spectrometer Leak Detector. (6) ASTM F 730-8l, Standard Test Methods for Hermeticity of Electron Devices by a WeightgainTest.
ASTMF73081 Standard Test Method for Hermeticity of Electron Devices by a WeightgainTest. (7) BIRAM, J. ,and BURROWS, B. , Bubbles tests for gas tightness, Vacuum, 14(7),1964,pp. 221-226.
The bubble test method for gas tightness, Vacuum, 14(7),1964,pp.221--226. (8) HOWL,D. ,A. ,and MANN, C. ,A. The backpressurizing technique for leak--testing. Vacuum,15(7，1965，pp.347～352.
The backpressure technique for leak--testing, Vacuum, 15(7),1965，Pp.347～352. (9) ASTON, D. ,BODIMEADE, A.,H. ,HALL,E. ,G.,and TAYLOR,C.,B. ,G.,The specifica.tions and testing of radioactive sources designated as \special form\ under the IAEA transport regula.tions,ReportEUR8053EN.1982.
International Atomic Energy Agency transport regulations, the technical conditions and testing methods of designated as "special form" radioactive sources, PeportEUR8053EN. 1982.
(10) DWIGHT,D. ,J. ,A new method for leak--testing sealed sources of radium-226 and thorium-228. Repot RCC---R 176(1964) and Addendum RCC—R 176(1965). A new method for leak--testing sealed sources of radium-226 and thorium-228. Report RCC-R176 (1964), supplemented in 1965. (ll) IAEA Safety Series No. 6, Regulations for the safe transport of radioactive materials, Vienna, 1985. (12) IAEA Safety Series No. 37 Advisory material for the application of the IAEA transport regulations. Vienna, 1987.2)
b) Sealed sources can only be inspected on site, and direct contact with the source is impossible or undesirable, because such inspection would expose the operator to excessive radiation doses. For example, high-activity teletherapy sources or other sources in sealed containers. In this case, the most accessible part of the source should be swabbed. It is worth noting that if the inspection finds radioactivity, even if it is below the 0.2kBq (5nCi) limit, measures should be taken to determine whether it is caused by leakage of the source. In this case, repeated inspections should be carried out at regular intervals to determine whether the measured radioactivity is increasing.
c) In some units (e.g., hospitals), when there are conditions for inspecting sealed sources by methods other than swabbing, or when the sources are shipped back to the manufacturer or other appropriate laboratories for inspection, the inspection methods recommended for the production of sealed sources in Table A1 can be used. If possible, a visual inspection should also be carried out on the sealed source.
Special attention should be paid to the need to ensure that the radiation exposure level is controlled within acceptable limits when regular inspections are carried out. Appendix B
(Suggested Appendix)
References
(1) McMASRERS, RC, ed., Non-destructive Testing Handbook, Vol. 1, Leak Testing, American Society for Non-destructive Testing American Society for Metals, 2nd ed. ,1982. (2) American National Standard for Radioactive Materials , Leakage Tests on Packages for Shipment ,ANSI No. 14.5--1987.
American National Standard ANSINo14.5—1987 Leakage Tests on Packages for Shipment of Radioactive Materials. (3) ASTM E 515-74 (Reapproved 1980), Standard Method of Testing for leaks Using Bubble Emis-sion Techniques. (4) ASTM F 98-72 (Reapproved 1977), Standard Recommended Practices for Determining Hermeticity of Electron Devices by a Bubble Test. 396
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(5) ASTM F 134-78, Standard Recommended Practices for Determing Hermeticity of electron deviceswith a Halium Mass Spectrometer Leak Detector. (6) ASTM F 730-8l, Standard Test Methods for Hermeticity of Electron Devices by a WeightgainTest.
ASTMF73081 Standard Test Method for Hermeticity of Electron Devices by a WeightgainTest. (7) BIRAM, J. ,and BURROWS, B. , Bubbles tests for gas tightness, Vacuum, 14(7),1964,pp. 221-226.
The bubble test method for gas tightness, Vacuum, 14(7),1964,pp.221--226. (8) HOWL,D. ,A. ,and MANN, C. ,A. The backpressurizing technique for leak--testing. Vacuum,15(7，1965，pp.347～352.
The backpressure technique for leak--testing, Vacuum, 15(7),1965，Pp.347～352. (9) ASTON, D. ,BODIMEADE, A.,H. ,HALL,E. ,G.,and TAYLOR,C.,B. ,G.,The specifica.tions and testing of radioactive sources designated as \special form\ under the IAEA transport regula.tions,ReportEUR8053EN.1982.
International Atomic Energy Agency transport regulations, the technical conditions and testing methods of designated as "special form" radioactive sources, PeportEUR8053EN. 1982.
(10) DWIGHT,D. ,J. ,A new method for leak--testing sealed sources of radium-226 and thorium-228. Repot RCC---R 176(1964) and Addendum RCC—R 176(1965). A new method for leak--testing sealed sources of radium-226 and thorium-228. Report RCC-R176 (1964), supplemented in 1965. (ll) IAEA Safety Series No. 6, Regulations for the safe transport of radioactive materials, Vienna, 1985. (12) IAEA Safety Series No. 37 Advisory material for the application of the IAEA transport regulations. Vienna, 1987.2)
b) Sealed sources can only be inspected on site, and direct contact with the source is impossible or undesirable, because such inspection would expose the operator to excessive radiation doses. For example, high-activity teletherapy sources or other sources in sealed containers. In this case, the most accessible part of the source should be swabbed. It is worth noting that if the inspection finds radioactivity, even if it is below the 0.2kBq (5nCi) limit, measures should be taken to determine whether it is caused by leakage of the source. In this case, repeated inspections should be carried out at regular intervals to determine whether the measured radioactivity is increasing.
c) In some units (e.g., hospitals), when there are conditions for inspecting sealed sources by methods other than swabbing, or when the sources are shipped back to the manufacturer or other appropriate laboratories for inspection, the inspection methods recommended for the production of sealed sources in Table A1 can be used. If possible, a visual inspection should also be carried out on the sealed source.
Special attention should be paid to the need to ensure that the radiation exposure level is controlled within acceptable limits when regular inspections are carried out. Appendix B
(Suggested Appendix)
References
(1) McMASRERS, RC, ed., Non-destructive Testing Handbook, Vol. 1, Leak Testing, American Society for Non-destructive Testing American Society for Metals, 2nd ed. ,1982. (2) American National Standard for Radioactive Materials , Leakage Tests on Packages for Shipment ,ANSI No. 14.5--1987.
American National Standard ANSINo14.5—1987 Leakage Tests on Packages for Shipment of Radioactive Materials. (3) ASTM E 515-74 (Reapproved 1980), Standard Method of Testing for leaks Using Bubble Emis-sion Techniques. (4) ASTM F 98-72 (Reapproved 1977), Standard Recommended Practices for Determining Hermeticity of Electron Devices by a Bubble Test. 396
GB 15849---1995
(5) ASTM F 134-78, Standard Recommended Practices for Determing Hermeticity of electron deviceswith a Halium Mass Spectrometer Leak Detector. (6) ASTM F 730-8l, Standard Test Methods for Hermeticity of Electron Devices by a WeightgainTest.
ASTMF73081 Standard Test Method for Hermeticity of Electron Devices by a WeightgainTest. (7) BIRAM, J. ,and BURROWS, B. , Bubbles tests for gas tightness, Vacuum, 14(7),1964,pp. 221-226.
The bubble test method for gas tightness, Vacuum, 14(7),1964,pp.221--226. (8) HOWL,D. ,A. ,and MANN, C. ,A. The backpressurizing technique for leak--testing. Vacuum,15(7，1965，pp.347～352.
The backpressure technique for leak--testing, Vacuum, 15(7),1965，Pp.347～352. (9) ASTON, D. ,BODIMEADE, A.,H. ,HALL,E. ,G.,and TAYLOR,C.,B. ,G.,The specifica.tions and testing of radioactive sources designated as \special form\ under the IAEA transport regula.tions,ReportEUR8053EN.1982.
International Atomic Energy Agency transport regulations, the technical conditions and testing methods of designated as "special form" radioactive sources, PeportEUR8053EN. 1982.
(10) DWIGHT,D. ,J. ,A new method for leak--testing sealed sources of radium-226 and thorium-228. Repot RCC---R 176(1964) and Addendum RCC—R 176(1965). A new method for leak--testing sealed sources of radium-226 and thorium-228. Report RCC-R176 (1964), supplemented in 1965. (ll) IAEA Safety Series No. 6, Regulations for the safe transport of radioactive materials, Vienna, 1985. (12) IAEA Safety Series No. 37 Advisory material for the application of the IAEA transport regulations. Vienna, 1987.American Society for Non-destructive Testing American Society for Metals, 2nd ed. ,1982. Handbook of Nondestructive Testing, Volume 1 Leakage Testing, American Society for Nondestructive Testing/American Society for Metals, 2nd ed., 1982. (2) American National Standard for Radioactive Materials, Leakage Tests on Packages for Shipment, ANSI No. 14.5--1987.
American National Standard ANSINo14.5-1987 Leakage Testing of Radioactive Materials Transport Packages. (3) ASTM E 515--74 (Reapproved 1980), Standard Method of Testing for leaks Using Bubble Emis-sion Techniques.
ASTME515-74 (Reapproved 1980) Standard Method of Testing for Leaks Using Bubble Emis-sion Techniques. (4) ASTM F 98--72 (Reapproved 1977), Standard Recommended Practices for Determining Hermeticity of Electron Devices by a Bubble Test. ASTM F98-72 (Reapproved 1977) Recommended Standard Practices for Determining Hermeticity of Electron Devices by a Bubble Test. 396
GB 15849---1995
(5) ASTM F 134--78, Standard Recommended Practices for Determing Hermeticity of electron devices with a Halium Mass Spectrometer Leak Detector. ASTM F134--78 Recommended Standard Practices for Determining Hermeticity of Electron Devices with a Halium Mass Spectrometer Leak Detector. (6) ASTM F 730-81, Standard Test Methods for Hermeticity of Electron Devices by a Weight gain Test.
ASTM F73081 Standard Test Methods for Hermeticity of Electron Devices by a Weight gain Test. (7) BIRAM, J. ,and BURROWS, B. , Bubbles tests for gas tightness, Vacuum, 14(7),1964,pp. 221-226.
The bubble test method for gas tightness, Vacuum, 14(7),1964,pp.221--226. (8) HOWL,D. ,A. ,and MANN, C. ,A. The backpressurizing technique for leak--testing. Vacuum,15(7，1965，pp.347～352.
The backpressure technique for leak--testing, Vacuum, 15(7),1965，Pp.347～352. (9) ASTON, D. ,BODIMEADE, A.,H. ,HALL,E. ,G.,and TAYLOR,C.,B. ,G.,The specifica.tions and testing of radioactive sources designated as \special form\ under the IAEA transport regula.tions,ReportEUR8053EN.1982.
International Atomic Energy Agency transport regulations, the technical conditions and testing methods of designated as "special form" radioactive sources, PeportEUR8053EN. 1982.
(10) DWIGHT,D. ,J. ,A new method for leak--testing sealed sources of radium-226 and thorium-228. Repot RCC---R 176(1964) and Addendum RCC—R 176(1965). A new method for leak--testing sealed sources of radium-226 and thorium-228. Report RCC-R176 (1964), supplemented in 1965. (ll) IAEA Safety Series No. 6, Regulations for the safe transport of radioactive materials, Vienna, 1985. (12) IAEA Safety Series No. 37 Advisory material for the application of the IAEA transport regulations. Vienna, 1987.American Society for Non-destructive Testing American Society for Metals, 2nd ed. ,1982. Handbook of Nondestructive Testing, Volume 1 Leakage Testing, American Society for Nondestructive Testing/American Society for Metals, 2nd ed., 1982. (2) American National Standard for Radioactive Materials, Leakage Tests on Packages for Shipment, ANSI No. 14.5--1987.
American National Standard ANSINo14.5-1987 Leakage Testing of Radioactive Materials Transport Packages. (3) ASTM E 515--74 (Reapproved 1980), Standard Method of Testing for leaks Using Bubble Emis-sion Techniques.
ASTME515-74 (Reapproved 1980) Standard Method of Testing for Leaks Using Bubble Emis-sion Techniques. (4) ASTM F 98--72 (Reapproved 1977), Standard Recommended Practices for Determining Hermeticity of Electron Devices by a Bubble Test. ASTM F98-72 (Reapproved 1977) Recommended Standard Practices for Determining Hermeticity of Electron Devices by a Bubble Test. 396
GB 15849---1995
(5) ASTM F 134--78, Standard Recommended Practices for Determing Hermeticity of electron devices with a Halium Mass Spectrometer Leak Detector. ASTM F134--78 Recommended Standard Practices for Determining Hermeticity of Electron Devices with a Halium Mass Spectrometer Leak Detector. (6) ASTM F 730-81, Standard Test Methods for Hermeticity of Electron Devices by a Weight gain Test.
ASTM F73081 Standard Test Methods for Hermeticity of Electron Devices by a Weight gain Test. (7) BIRAM, J. ,and BURROWS, B. , Bubbles tests for gas tightness, Vacuum, 14(7),1964,pp. 221-226.
The bubble test method for gas tightness, Vacuum, 14(7),1964,pp.221--226. (8) HOWL,D. ,A. ,and MANN, C. ,A. The backpressurizing technique for leak--testing. Vacuum,15(7，1965，pp.347～352.
The backpressure technique for leak--testing, Vacuum, 15(7),1965，Pp.347～352. (9) ASTON, D. ,BODIMEADE, A.,H. ,HALL,E. ,G.,and TAYLOR,C.,B. ,G.,The specifica.tions and testing of radioactive sources designated as \special form\ under the IAEA transport regula.tions,ReportEUR8053EN.1982.
International Atomic Energy Agency transport regulations, the technical conditions and testing methods of designated as "special form" radioactive sources, PeportEUR8053EN. 1982.
(10) DWIGHT,D. ,J. ,A new method for leak--testing sealed sources of radium-226 and thorium-228. Repot RCC---R 176(1964) and Addendum RCC—R 176(1965). A new method for leak--testing sealed sources of radium-226 and thorium-228. Report RCC-R176 (1964), supplemented in 1965. (ll) IAEA Safety Series No. 6, Regulations for the safe transport of radioactive materials, Vienna, 1985. (12) IAEA Safety Series No. 37 Advisory material for the application of the IAEA transport regulations. Vienna, 1987.Bubbles tests for gas tightness, Vacuum, 14(7), 1964, pp. 221-226. (8) HOWL, D. , A. , and MANN, C. , A. The backpressurizing technique for leak--testing. Vacuum, 15(7), 1965, pp. 347-352. (9) ASTON, D. ,BODIMEADE, A.,H. ,HALL,E. ,G.,and TAYLOR,C.,B. ,G.,The specifica.tions and testing of radioactive sources designated as \special form\ under the IAEA transport regula.tions,ReportEUR8053EN.1982.
International Atomic Energy Agency transport regulations, the technical conditions and testing methods of designated as "special form" radioactive sources, PeportEUR8053EN. 1982.
(10) DWIGHT,D. ,J. ,A new method for leak--testing sealed sources of radium-226 and thorium-228. Repot RCC---R 176(1964) and Addendum RCC—R 176(1965). A new method for leak--testing sealed sources of radium-226 and thorium-228. Report RCC-R176 (1964), supplemented in 1965. (ll) IAEA Safety Series No. 6, Regulations for the safe transport of radioactive materials, Vienna, 1985. (12) IAEA Safety Series No. 37 Advisory material for the application of the IAEA transport regulations. Vienna, 1987.Bubbles tests for gas tightness, Vacuum, 14(7), 1964, pp. 221-226. (8) HOWL, D. , A. , and MANN, C. , A. The backpressurizing technique for leak--testing. Vacuum, 15(7), 1965, pp. 347-352. (9) ASTON, D. ,BODIMEADE, A.,H. ,HALL,E. ,G.,and TAYLOR,C.,B. ,G.,The specifica.tions and testing of radioactive sources designated as \special form\ under the IAEA transport regula.tions,ReportEUR8053EN.1982.
International Atomic Energy Agency transport regulations, the technical conditions and testing methods of designated as "special form" radioactive sources, PeportEUR8053EN. 1982.
(10) DWIGHT,D. ,J. ,A new method for leak--testing sealed sources of radium-226 and thorium-228. Repot RCC---R 176(1964) and Addendum RCC—R 176(1965). A new method for leak--testing sealed sources of radium-226 and thorium-228. Report RCC-R176 (1964), supplemented in 1965. (ll) IAEA Safety Series No. 6, Regulations for the safe transport of radioactive materials, Vienna, 1985. (12) IAEA Safety Series No. 37 Advisory material for the application of the IAEA transport regulations. Vienna, 1987.
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