This standard specifies the sanitary requirements and inspection requirements for radiation protection during the use of sealed radioactive sources for oil (gas) field logging. This standard applies to the use of sealed (neutron, gamma) radioactive sources (hereinafter referred to as radioactive sources) for logging and logging research in oil (gas) fields. GBZ 142-2002 Sanitary Protection Standard for Sealed Radioactive Sources for Oil (Gas) Field Logging GBZ142-2002 Standard download decompression password: www.bzxz.net

ICS13.100
National occupational health standard of the People's Republic of China GBZ142-2002
Radiological protection standard for sealed radioactive sources for oil (gas) field logging
used
2002-04-08 Issued
dlogging
inoilandgas-field
2002-06-01 Implementation
Ministry of Health of the People's Republic of China
Appendix A
Normative references
Radiation health protection requirements for sealed radioactive sources for logging and use Inspection of the performance of sealed radioactive sources and source-carrying equipment for logging Personal dose monitoring
(Normative Appendix)
Appendix B (Informative Appendix)
Inspection methods for surface contamination and leakage of radioactive sources Conversion coefficients between monoenergetic neutron injection and effective dose
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 GB8922-88 and this standard, this standard shall prevail. Chapters 3 to 5 and Appendix A of this standard are mandatory contents, and the rest are recommended contents. Appendix A of this standard is a normative appendix, and Appendix B is an informative appendix. This standard is proposed and managed by the Ministry of Health.
Drafting unit of this standard: Institute of Radiation Medicine, Shandong Academy of Medical Sciences. Main drafters of this standard: Deng Daping, Zhu Jianguo, Qiu Yuhui, Hou Jinpeng, He Shunsheng. This standard is interpreted by the Ministry of Health.
Standard for sanitary protection of sealed radioactive sources for oil (gas) well logging 3
GBZ142-2002
1 Scope
This standard specifies the sanitary requirements and inspection requirements for radiation protection during the use of sealed radioactive sources for oil (gas) logging.
This standard is applicable to the use of sealed (neutron,) radioactive sources (hereinafter referred to as radioactive sources) for logging and logging research in oil (gas) fields.
2 Normative references
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.
4075 Classification of sealed radioactive sources
4076 General provisions for sealed radioactive sources
2894 Safety signs
3 Requirements for radiation health protection of sealed radioactive sources for combined use 3.1 Radioactive sources
Radioactive sources shall comply with the requirements of GB4076 and GB4075 to ensure reliable sealing performance. The shell of the radioactive source shall be marked with the radioactive source number and the name or symbol of the radioactive source nuclide (including neutron source target nuclide). There shall also be explanatory information on the radioactive source, the contents of which shall at least include: radioactive source number, nuclide name, activity, radiation type, physical and chemical properties, radiation output rate (or injection rate) of the used rays and its measurement date, surface contamination and leakage test results and test date, etc. 3.2 Containers for storing and transporting radioactive sources
3.2.1 The cans (barrels) for storing or transporting radioactive sources (hereinafter referred to as source cans) should be easy to carry and take out and put in radioactive sources, and must be lockable; the outer surface of the source can should be labeled with the source can number, nuclide name and activity, and printed with clear ionizing radiation warning signs and the name of the user unit in accordance with the provisions of GB2894.
3.2.2 When the source can is used for logging, the air kerma rate at 5cm and 1m from the surface of the source can shall not be greater than the control value in Table 1.
Table 1 Control value of air kerma rate at 5cm and 1m from the source tank surface when the source is loaded in the source tank for logging Radioactive source
2Am-Be
3.3 Radioactive source storage
GBq(Ci)
）200（5）
≤200(5)
）20(0.5)
≤20(0.5)
Air kerma rate
(mGy·h')
3.3.1 Radioactive source storage (hereinafter referred to as source storage) shall be an independent building with surrounding walls. No one shall live, work or place flammable, explosive or other dangerous items within the walls. Ionizing radiation warning signs shall be set up in obvious positions in the source storage. 3.3.2 A pit for storing radioactive sources and their source tanks should be set up in the source storehouse, which is recessed 150cm below the ground and 10-15cm above the ground. The pit should be covered with a protective cover of appropriate material and thickness. All radioactive sources and waste sources should be stored in the pit. Frequently used radioactive sources should be stored in one pit.
3.3.3 The kerma rate of air on the surface of the pit protective cover should be less than 25uGy·h. The kerma rate of air outside the source storehouse should be less than 2.5μGy·hl. 3.3.4 A source storehouse storing neutron sources greater than 200GBg (5Ci) and Y sources greater than 20GBq (0.5Ci) should have mechanical lifting and conveying equipment. 3.3.5 The source storehouse should have good lighting and ventilation, and sufficient usable area to facilitate the storage and collection of radioactive sources.
3.3.6 The entrance and exit of the radioactive source of the source library should be equipped with a dose monitoring device, and it should be able to give a warning signal to indicate whether there is a radioactive source in the source tank entering or leaving the library. 3.3.7 The source library must establish a management system for the entry and exit of radioactive sources, which must be kept by a dedicated person, and two people and two locks must be used to establish a ledger, register, detect and record with instruments, and conduct regular inventory. 3.4 Vehicles carrying radioactive sources
3.4.1 Vehicles carrying radioactive sources for oilfield logging (referred to as source transport vehicles) should be equipped with devices to fix source tanks. Appropriate safety protection measures should be taken when using source transport vehicles to transport radioactive sources. Source transport vehicles (including dual-purpose source transport vehicles that also transport radioactive sources for logging) that do not take adequate safety protection measures shall not enter densely populated areas or stay in public parking lots. 3.4.2 The air kerma rate inside and outside the transport vehicle shall not be greater than the control value in Table 2 Table 2 Control value of air kerma rate inside and outside the transport vehicle Air kerma rate of the transport vehicle (μGy·h') Measurement position
Driver's seat
External surface of the vehiclebZxz.net
2m outside the vehicle
Note: Under the condition that the annual personal dose of the driver is strictly controlled, the air kerma rate can be appropriately relaxed, but it shall not exceed 2 times.
3.5 Protection of operating radioactive sources
3.5.1 When operating radioactive sources, factors such as the activity of the radioactive source, operating distance, operating time and protective shielding should be fully considered, and the most optimized protection measures should be taken to ensure that the dose received by the operator is controlled at the lowest level that can be reasonably achieved. 3.5.2 Radioactive sources shall not be operated with bare hands. When there is no mechanized operation, tools that meet the following requirements should be used according to the different activities of the source:
a) For neutron sources greater than or equal to 200GBq (5Ci) and sources greater than or equal to 20GBq (0.5Ci)6
, the handle length of the operating tool shall not be less than 100cm; b) For neutron sources less than 200GBq and sources less than 20GBq, the handle length of the operating tool shall not be less than 50cm.
3.5.3 The part of the radioactive measuring instrument placed under the instrument (hereinafter referred to as the instrument under the instrument) shall be scrubbed with a tool with a handle length of not less than 50cm because it contains a radioactive source. 3.5.4 When the instrument under the instrument enters and exits the instrument port, it shall be supported by a tool with a handle length of not less than 100cm. 3.5.5 When performing special operations such as replacing the source housing, spring, sealing ring or packing, special operating tools and protective shielding equipment shall be available. The air kerma rate on the side of the protective shield close to the human body shall be less than 1mGy·h.
3.6 Additional requirements for outdoor operation of radioactive sources When operating radioactive sources outdoors, warning signs (or warning measures) must be set up on the boundary where the air kerma rate is 2.5 uGy·h to prevent unauthorized personnel from entering the operating area within the boundary.
4 Inspection of the performance of sealed radioactive sources and source-carrying equipment for well logging 4.1 Before new radioactive sources and equipment are put into testing and use, the following items should be inspected: a) Radiation field air kerma ratio;
b) Radioactive source leakage, see Appendix A (normative appendix); c) Radioactive contamination of the surface of the radioactive source, operating tools and source chamber of the downhole instrument, see Appendix A (normative appendix);
d) The protective effect and performance of the source tank and protective shielding, etc. e) The air kerma ratio inside and outside the source library:
f) The air kerma ratio inside and outside the source transport vehicle7
g) The length and mechanical properties of the operating tools for loading and unloading sources: Among them, the tests of d), e), and f) are tested at selected points on site using calibrated appropriate instruments, and the selection of test points should depend on the specific working conditions. 4.2 Inspection after commissioning and use:
4.2. 1 Inspections of items a), d), e), f) and g) in 4.1 shall be conducted annually, and inspections of items b) and e) shall be conducted every six months to one year. 4.2.2 Inspections of items b) and c) in 4.1 shall be conducted in a timely manner in case of any of the following situations: - After special operations such as replacement of the shell, spring and sealing ring of the radioactive source; - After the radioactive source falls into a well or is recovered after being lost or stolen; - When the radioactive source is suspected of being damaged for various reasons. 4.2.3 When obvious deformation of the source tank or protective shield is found or changes in its internal structure are suspected: Inspection of item d) in 4.1 shall be conducted additionally.
5 Personal dose monitoring
5.1 Routine monitoring of personal dose of external exposure shall be conducted for personnel using radioactive sources for measurement, and personal dosimeters shall be able to simultaneously monitor the dose of ?-rays and neutrons. Neutron dose estimation refers to the data provided in Appendix B (Informative Appendix). 5.2 Before a new radioactive source, new measuring equipment or new measuring process is put into measurement and use, the cumulative dose of the operators during the whole measuring process shall be measured or estimated. The neutron dose estimation shall refer to the data provided in Appendix B (Informative Appendix). Appendix A
(Normative Appendix)
Test method for surface contamination and leakage of radioactive sources"Test method for surface contamination
Wet wipe method:
Use a highly hygroscopic soft material (such as filter paper or cotton) dipped in a liquid that does not corrode the surface material of the cladding but can remove radioactive contamination, wipe the entire surface of the source, and measure the radioactive activity on the wiped material. When the activity is less than 200Bg, the source surface can be regarded as uncontaminated. A1.2 Immersion method:
Immerse the source in a liquid that does not corrode the surface of the source but can remove radioactive contamination, keep it at (50±5)°C for 4h, take out the source, and measure Measure the total radioactivity in the liquid. If the radioactivity is less than 200Bq, the source surface can be considered uncontaminated.
A2 Leakage inspection method
A2.1 Wet wiping method, same as A1.1
A2.2 Immersion method, same as A1.2
A2.3 Dry wiping method:
Place the source in an ultrasonic cleaner in advance, clean it with a non-corrosive liquid such as trichloroethylene or ethylenediaminetetraacetic acid (EDTA) for 1Omin, rinse with water and then rinse with acetone, and leave it to dry. Wipe the surface of the source with a soft material (such as filter paper or cotton), measure the radioactivity on the wiped object, if it is less than 200Bg, After 7 days, wipe the source surface again and measure the radioactivity on the wipe. If the radioactivity is still less than 200Bq, the source can be considered leak-free.
Note: 1) This test method refers to GB4076-83 and GB4075-83. 2) Such as water or low-concentration detergents and chelating agents. Appendix B
(Informative Appendix)
Energy (Mev)
2.0×10*6
1.0×10~5
5.0×10~5
1.0×10~3
1.0×10°
1.2×10°||tt| |4.0×10°
6.0×10°
7.0×10°
8.0×10°
Energy (MeV)
Conversion coefficient of monoenergetic neutron fluence and effective dose When monoenergetic neutrons are incident on the adult human simulation model under various geometric conditions, the effective dose per unit neutron fluence (E/Φ, pSvcm) AP
a. No data available
AP: front irradiation, PA: rear irradiation, RLAT: right irradiation, LLAT: left irradiation, ROT: isotropic irradiation.
Rotational irradiation, ISO:
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