This standard specifies several inspection methods for prototypes of packages designed for transporting radioactive materials. These methods are formulated to cooperate with the implementation of national regulations and standards for the safe transportation of radioactive materials. The purpose is to inspect whether the radioactive contents in the package are still leaking and whether the increase in radiation leakage from the outside of the package is still below the limit after the tests in the above transportation regulations. GB/T 9229-1988 Leakage inspection of contents and radiation of radioactive material packaging GB/T9229-1988 standard download decompression password: www.bzxz.net

UDC621.039.584.001.4
National Standard of the People's Republic of China
GB9229-88
Radioactive materials--Packagings--Tests for contents leakage and radiation leakagePublished on June 6, 1988
Published by the National Bureau of Standards
Implemented on January 1, 1989
National Standard of the People's Republic of China
Radioactive materials-Packagings---Tests for contents leakage and radiation leakageUDC621:039
.584.001.4bZxz.net
GB9229-88
This standard adopts the international standard ISO2855 "Radioactive material-Package-Content leakage and radiation leakage test". 1 Subject content and scope of application
This standard specifies several test methods for prototypes of packages designed for transporting radioactive materials. These methods are formulated to cooperate with the implementation of national regulations and standards for the safe transportation of radioactive materials. The purpose is to test whether the radioactive contents in the package are still leaking and whether the increase in radiation leakage from the outside of the package is still below the limit after the tests in the above transportation regulations. This standard cannot be applied to all radioactive material packages. Its scope of application is: a. The radioactive content leakage test method is formulated for the sealing of a certain layer of packaging or the entire containment system containing radioactive materials. It is applicable to packages of liquid or powdery materials with low specific activity, such as cans and type A packaging. For packages of uranium-radium series radioactive materials, if the measurement of their daughters (hydrogen-222, etc.) is more sensitive, it is not necessary to use the method described in this standard, but the methods in Appendix E1.1.5 and E1.1.6 of GB4075 Classification of Sealed Radioactive Sources can be used for reference. Radiation leakage inspection is applicable to the radiation dose rate outside the shielding layer. If the design has considered that the dose rate is reduced due to the increased protection distance of the outer packaging, it can also be inspected together with the outer packaging. However, for some special sizes or situations where the inspection process is difficult due to certain characteristics, the method of this standard should not be used. 2 Reference Standards
GB4075 Classification of Sealed Radioactive Sources
3 Terminology
3.1 (Radioactive) Contents refers to the materials containing radioactive nuclides in the package and the gases, liquids or solids in the package contaminated by these radioactive nuclides.
3.2 Prototype inspection
Various performance inspections conducted on a newly designed package before formal use. 3.3 Simulated radioactive material is a test sample made by replacing the original radionuclides with radionuclides with similar energy and physicochemical properties but lower activity.
3.4 ​​Leakage of radioactive contents Radioactive contents leak out of the package in any form. 3.5 Radiation leakage The radiation level outside the package exceeds the limit specified for safe transportation. 4 Radioactive Content Leakage Inspection
4.1 Method Basis
A leak hole with an area of ​​10-mm or less (equivalent to a standard nitrogen leakage rate of about 13.33Pam/s), when inspected, the leakage within the first 10mm will not exceed 1.5×10-L, equivalent to 2.53μPa.m/s Approved by the Ministry of Nuclear Industry of the People's Republic of China on February 5, 1988 and implemented on January 1, 1989
GB9229-88
According to the requirements of the Regulations on the Safe Transport of Radioactive Materials, the radioactivity leaked from the package should not exceed 1850Bg+ This value is approximately equivalent to a standard nitrogen leakage rate of 13.33μPam/s for solid radioactive materials in sealed containers, and approximately equivalent to 0.1333uPam/s for liquids. Based on the above values, this standard stipulates a dual method of using negative pressure to detect leaked gas and radioactivity. For solid powders, only gas leakage needs to be inspected, while for liquids, both need to be inspected. 4.2 Device
4.2.1 The immersion tank can be designed as a cylinder and should be made of transparent materials or equipped with a peep window. The tank is required to withstand an internal pressure of more than 0.3MPa. The tank should be equipped with a pressure gauge and water inlet and outlet valves. There is a bracket inside the tank to fix the sample. When filled with water, any part of the sample should be more than 40mm above the water surface, and any part of the sample can be observed by rotating the tank. 4.2.2 The instrument for measuring radioactive activity should have a detection sensitivity of not less than 0.4Bq for β particles and not less than 80Bg for radiation. 4.3 Simulated radioactive solution
It is best to use P, radionuclides with short half-life and high energy, such as Na. The radioactivity concentration of the prepared solution should be equal to a=sx
where: a is the radioactivity concentration of the simulated solution, Bq/LS-instrument detection sensitivity, Bq,
V is the volume of the solution in the tank, L;
Vs is the sampling volume, L;
L is the minimum detectable leakage, L=1.5×10-sL/10min. 4.4 Operation steps
........(1)
The sample is loaded with simulated radioactive solution. After the environmental test specified for safe transportation, the non-sealed layer outside the package is removed, and the package is placed in the immersion tank, fixed, and the gas is pressed into the tank to 0.2MPa, maintained for 15min, and then deionized water is injected until the water level is at least 40mm higher than the sample surface. The pressure in the tank should not be reduced during water injection. After filling with water, quickly release the air to normal pressure, and immediately observe for 5 minutes to see if there are continuous bubbles escaping from various parts. Then rotate the tank so that all parts of the sample have a chance to be on the upper part, but still keep it more than 40mm above the water surface. Observe for another 5 minutes. If no continuous bubbles appear, repeat all the above tests once, and finally take a sample (at least 0.1) from the tank to measure its radioactivity. 4.5 Discrimination
If the cargo package contains powdered radioactive materials, when there are no continuous bubbles on the cargo package, it can be considered as leak-free. If the cargo package contains liquid radioactive materials, in addition to no bubbles, the sample can be considered as leak-free if no radioactivity is detected. 5 Radiation Leakage Inspection
5.1 Method Basis
After the radioactive material cargo package has been tested under the normal belt transportation conditions, when the radiation level on the surface of the cargo package increases due to shielding damage, it shall not exceed 20% according to the regulations on the safe transportation of radioactive materials. In addition, after the accident condition test of transport for B (U) type cargo packages, the radiation level at 1m from the surface of the cargo package shall not exceed 10mSv/h. According to actual research results, when there is a 1cm defect on the shielding surface as a crack or notch, it is difficult to detect if the dose rate increases by less than 100%. If there is a 100cm defect on the shielding surface, it cannot be detected if the dose rate increases by less than 20%. Therefore, the methods given in this standard can meet the requirements of safe transportation regulations in most cases. Among them, the X-ray film sensitivity method is suitable for detecting packages with relatively small reduction in radiation shielding effectiveness, which is used for A type cargo packages. The direct measurement of radiation method is suitable for detecting and measuring packages with relatively large reduction in shielding effectiveness, which can be used for both A and B type cargo packages. If the size of the cargo package or other reasons cannot be used in the method, a basic method that meets the requirements of transportation regulations shall be designed separately. 5.2 X-ray film photosensitive method
5.2.1 Equipment and materials
The sensitivity range of black illuminance (D) of black meter should be 0～3X-ray film
X-ray film intensifying screen (optional)
GB9229—88
The source quantity should be close to the actual one, and the activity should make the film produce a blackness (D) of not less than 0.01 within a suitable time (e.g. 5h)Radiation source
5.2.2 Inspection steps
Before the actual inspection, standard operating procedures should be specified in advance. Determine the exposure time and development conditions according to the actual photosensitivity of X-ray film and the activity of the source.
Apply the film to the outer surface of the cargo package. If the cargo package has a special shape, it can be covered with an aluminum tube and then wrapped with X-ray film. The thickness of the aluminum tube shall not exceed 1mm, and the distance between the aluminum tube and the cargo package shall not exceed 50mm. The exposure shall be carried out in two times, the first time shall be carried out before the environmental test specified for safe transportation. The second time is after the test. The film used for the two irradiations and the irradiation time should be the same, and they should be washed at the same time. The blackness of the washed film should not be less than 1.
5.2.3 Judgment
Measure the blackness of the film. If the blackness of the two films is the same, it can be considered qualified. 5.3 Direct wall radiation measurement method
5.3.1 Device
Probe with sodium iodide crystal and matching irradiation or dose meter. A rotating platform for placing cargo packages can be designed. The platform is synchronized with a rotating arm with a probe that can move up and down. When the platform rotates, the rotating arm can move back and forth from the edge of the platform to the top of the center and the distance from the center of the source should be kept roughly equal. 5.3.2 Radioactive source
The radioactive source can use the same or similar energy as the nuclides in the actual cargo package. Its activity is considered according to the shielding capacity of the cargo package specified in the design. For type A cargo packages, the actual radioactive source can be used. The measuring instrument is pre-calibrated according to the 20% range of the source after the package shielding at 200% of the irradiation rate. Place the cargo package in the center of the turntable, rotate the turntable, and scan the probe up and down. For each reciprocating cycle, the turntable rotates no more than 10°. The probe should always be aligned with the center of the source.
The cargo package should be measured once before and after the environmental conditions test specified for safe transportation. The conditions and instruments used for the measurement should be the same. 5.3.3 Judgment
Compare the two measurement records. If there is no change, it is considered qualified. Additional remarks:
This standard is proposed by the National Nuclear Energy Standardization Technical Committee. This standard is drafted by the Institute of Atomic Energy of the Ministry of Nuclear Industry.
National Standard of the People's Republic of China||tt| ... Printed by Xinhua Bookstore, Beijing Distribution Office Distributed by Xinhua Bookstores in all regions Sold by Xinhua Bookstores in all regions Reproduction is prohibited
Copyright reserved
Format 880×12301/16
Printing sheet 1/2
Word count 6000
First edition February 1989 First printing February 1989 Number of copies 1-2000
No. 5: 1550661-6087
Mark month 105-36
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.