GBZ 118-2002 Hygienic protection standard for well logging with non-sealed radioactive sources in oil (gas) fields
Some standard content:
Ics13.100
National occupational health standard of the People's Republic of China GBZ118-2002
Radiological protection standards for unsealed radioactive sources logging in oil (gas) field Issued on April 8, 2002
Ministry of Health of the People's Republic of China
Implementation on June 1, 2002
1 Scope
2 Normative references
3 Terms and definitions
4 Radiological health protection requirements for laboratories and other facilities 5 Radiological health protection requirements for the operation of unsealed sources
6 Radiological health protection requirements for the transportation of unsealed sources for logging 7 Protection monitoring
Appendix A (informative appendix) Principles and emergency measures for handling radioactive contamination accidents
This standard is formulated in accordance with the Occupational Disease Prevention and Control Law of the People's Republic of China. In case of any inconsistency between the original standard GB16358-1996 and this standard, this standard shall prevail.
Chapters 4 to 7 of this standard are mandatory contents, and the rest are recommended contents. Appendix A of this standard is an informative appendix.
This standard is proposed and managed by the Ministry of Health.
The drafting units of this standard are: Institute of Radiation Medicine, Shandong Academy of Medical Sciences, Shengli Oilfield Health and Epidemic Prevention Station. The main drafters of this standard are: Zong Xiyuan, Qiao Dongliang, Deng Daping, Yang Yingxiao, Sun Zuozhong, Zhang Huazong, Hu Shiliang. This standard is interpreted by the Ministry of Health.
1 Scope
Health Protection Standard for Well Logging of Oil (Gas) Using Unsealed Radioactive Sources GBZ118-2002
This standard specifies the radiation health protection requirements for well logging of unsealed radioactive sources (hereinafter referred to as unsealed sources) in oil (gas) fields.
This standard applies to the practice of radioactive tracer measurement using unsealed sources in oil (gas) fields. 2 Normative references
The clauses in the following documents become clauses of this standard through reference in this standard. For any dated referenced document, its subsequent amendment (excluding errata) or revision is 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, its latest version is applicable to this standard GBZ128 Occupational external radiation personal monitoring specification GB8703
GB9133
GB11806
GB11930
Radiation protection regulations
Radioactive waste classification standards
Regulations on safe transportation of radioactive materials
Radiation protection regulations for handling open radioactive materials 3 Terms and definitions
The following terms and definitions apply to this standard. 3.1
Radioactive tracer logging Radioactive tracer logging is a method of using radioactive tracers injected into oil wells to determine the movement state of fluids in wells or between formation pores, their distribution patterns, and engineering quality parameters.
In-well releaser In-well releaser A device that contains radioactive tracers and can be sent downhole to release them into the well at a fixed point or at a fixed time. 4 Radiological health protection requirements for laboratories and other facilities 4.1 Laboratories
4.1.1 Classification, grading, site selection and layout of laboratories 4.1.1.1 According to the requirements of GB8703, combined with the equivalent annual amount of radionuclides used in oil well logging and the maximum equivalent daily operation volume, the non-sealed source laboratory for oilfield well logging belongs to the third category open unit, Class B or Class C workplace. 4.1.1.2 Class B laboratories can be set up in a separate building, or on the first floor or one end of a general building, but must have a separate entrance and exit.
4.1.1.3 The laboratory should be divided into three areas according to the level of operational radioactivity and the degree of danger of radioactive contamination: clean area (including office, lounge, etc.), low activity area (including instrument maintenance room, radioactive measurement room and changing room, shower and radiation dose monitoring room, etc.) and high activity area (including bottle opening and filling room, source storage and waste storage facilities, etc.). The airflow direction should be from low activity area to high activity area. 4.1.2 Laboratory health protection requirements
4.1.2.1 The structure of the floor, walls, doors and windows and internal equipment should be simple, the surface should be smooth and seamless; the floor should be paved with replaceable and easy-to-decontaminate materials, and a floor drain should be set to connect to the general drainage system: the wall below 2m above the ground should be painted with acid and alkali resistant paint. 4.1.2.2 A fume hood (or work box) must be set up in the bottle opening and filling room. The negative pressure in the hood should be maintained at 200Pa, and its exhaust system should be equipped with a filter device: the cabinet is connected to the low-level radioactive waste liquid depreciation facility: the cabinet should also be equipped with protective facilities for shielding β and γ external radiation. 4.1.2.3 There should be good ventilation and lighting. The ventilation frequency in the Class B laboratory is 4 to 6 times per hour, and the ventilation frequency in the Class C laboratory is 3 to 4 times per hour (or natural ventilation). 4.1.2.4 Set up special collection containers or storage facilities for radioactive waste liquid and solid waste. 4.1.2.5 A sanitary passage room (including changing clothes, showers and radiation dose monitoring facilities, etc.) should be set up in the Class B laboratory, and facilities for changing clothes, washing hands and radiation dose monitoring should be set up in the Class C laboratory. The water supply adopts a foot pedal or elbow switch. 4.2 Source Repository
4.2.1 The source reservoir should be connected to (or adjacent to) the bottle opening and filling room and have a separate entrance and exit. The materials and structures of walls, doors and windows should have the functions of anti-theft and fire prevention.
4.2.2 The floor of the source storage warehouse should be smooth and seamless, easy to clean and easy to wash. The source storage warehouse should have sufficient usable area and good ventilation and lighting.
4.2.3 The walls and doors and windows should have sufficient protective thickness to ensure that the exposure dose to the public meets the requirements of GB8703. 4.2.4 A source pit or pool must be set up in the source storage warehouse. The source pit (pool) should be kept dry, and its upper mouth should be at least 10 to 20 cm above the ground. It should be equipped with a protective cover and can be locked. The air kerma rate in the indoor personnel activity area shall not exceed 25μGy·h. 4.3 Source storage container
4.3.1 All radionuclides and tracers must be placed in tightly sealed containers, and then placed in storage and transportation containers with certain shielding capabilities according to their radiation characteristics. The outer surface of the inner container should have a label with the tracer production batch number and the name of the radionuclide, chemical form, physical state, activity and calibration date, as well as a clear ionizing radiation warning mark. An instruction manual containing the above content is also attached. 4.3.2 The inner container containing the radioactive tracer should be tough and have good sealing performance. Containers that are easily damaged and broken should not be used.
4.3.3 Storage and transportation containers should be easy to carry and easy to put in and take out of the container, and must be lockable. In addition to the container number and the name of the radionuclide, activity and calibration date, there must also be a clear electric radiation warning mark and the words "Beware of ionizing radiation" and the name of the unit using it. The air kerma rate at 5cm from the outer surface of the protective container shall not exceed 25uGy·h, and the air kerma rate at 1m shall not exceed 2.5uGy·h. The radioactive contamination on the outer surface of the storage and transportation container shall not exceed 4X10Bq·cm2 for α and 4Bq:cm2 for β.
4.3.4 The wall thickness of the storage and transportation container for storing β radioactive nuclides must be greater than the maximum range of β particles in the container material. When the maximum energy of β particles is above 1MeV, attention should be paid to shielding bremsstrahlung. 4.4 Waste liquid and waste storage facilities
4.4.1 The classification of radioactive liquid and solid waste shall be carried out in accordance with the provisions of GB9133. 4.4.2 The discharge of low-level radioactive waste liquid shall be carried out in accordance with the provisions of GB8703. 4.4.3 Radioactive waste barrels should be set up in the laboratory, and all solid radioactive wastes should be thrown into the waste barrels for collection or placed in storage facilities for temporary storage. The air kerma rate on the surface of the waste barrels and storage facilities shall not exceed 25μGy·h4.4.4 Waste liquids that cannot be discharged, such as residual radioactive solutions from experiments and high-concentration container washing solutions, shall be collected in special collection containers according to the length of their half-lives and can be sealed in storage facilities as radioactive waste. 5 Radiation health protection requirements for non-sealed source operations 5.1 General requirements
The operation of unsealed sources for logging should follow the radiation protection principles and requirements in GB11930, and pay special attention to the following points: a) Under the condition of meeting the technical requirements, select radionuclides with low toxicity, low radiation energy and short half-life, and try to reduce the activity used and stored;
b) Use remote operation, try to use mechanical, automatic and closed methods; c) Be proficient in operation technology and strive to shorten the operation time; d) Deal with radioactive contamination in time to prevent the spread of contamination; e) Minimize the generation of radioactive waste liquid and waste; f) Strengthen safety protection management to prevent the occurrence of radioactive contamination accidents. 5.2 Laboratory operation health protection requirements
5.2.1 Before operating a radioactive source, you should make full preparations, be familiar with the operating procedures, check the name, activity, factory date, total amount and packaging amount of the radioactive material, check whether the instruments and equipment are normal, whether the ventilation is good, and check whether the actual activity is consistent with the marked activity. 5.2.2 When adopting new technologies and methods, they should be confirmed to be feasible through "simulation tests", and only after being recognized as proficient in the operation by the radiation health technical service agency can they be officially operated.
5.2.3 Operations such as opening bottles, filling, preparing, evaporating, drying solutions, or when gases or aerosols are generated must be carried out in a fume hood or operating box. Radioactive operations that are prone to contamination must be carried out on a workbench covered with easily decontaminated materials or in a sugar porcelain plate. 5.2.4 When absorbing radioactive solutions, it is strictly forbidden to absorb by mouth. 5.2.5 The workplace should be wet-cleaned frequently, and cleaning tools must not be mixed with non-radioactive areas. 5.2.6 Radiation workers must understand the principles of handling radioactive contamination accidents and be familiar with the handling methods of radioactive contamination accidents, see Appendix A (Informative Appendix).
5.3 Health protection requirements in well logging
5.3.1 The release of radioactive tracers during logging should be carried out by the release method below the well. The release device containing the tracer should be sent to a certain depth below the well together with the logging instrument, and the radioactive tracer should be released below the well by the control of the well head. 5.3.2 When the wellhead release method is adopted, the tracer should be first encapsulated in a container or package that is easy to break or crack in the well, and the method of one-time delivery to the wellhead should be implemented; it is forbidden to use the method of directly pouring the tracer into the wellhead to prevent contamination of the operation site. 5.3.3 Before releasing the radioactive tracer, it is necessary to carefully check that the gates at the wellhead, the pressure and water flow of the well pipe are normal, the well pipe and casing are unobstructed, and the structure of the well port thread plug and the blowout prevention box is tight, and then release the tracer according to the normal operating procedures to prevent the well water containing radioactive tracers from spraying back from the well port and polluting the well site and the environment.
5.3.4 When operating radioactive tracers and supporting the source downhole releaser or injection tester in and out of the wellhead, operating tools of appropriate length must be used. 5.3.5 The air kerma rate at the logging site exceeds 2.5uGy·h, and the area that may be contaminated by radioactivity should be designated as a warning area. And set up ionizing radiation warning signs around it to prevent unauthorized personnel from entering. 5.3.6 On-site measurement and operation personnel must wear special work clothes, hats, masks, gloves and other personal protective equipment that meet the requirements, and they must be kept and handled in a unified manner. When operating strong Y radioactive sources, lead protective screens and lead protective glasses should also be used. 5.3.7 Before and after the construction of radioactive tracer logging, routine monitoring must be carried out in accordance with 7.3 and 7.4, and abnormalities must be properly handled in a timely manner. 5.3.8 Unused or remaining radioactive tracers (or together with releasers) and radioactive waste must be brought back to the laboratory for treatment. 5.3.9 After each use, the isotope chamber of the releaser and the isotope injection instrument must be brought back to the laboratory and rinsed, decontaminated, repaired and maintained in a special washing pool by a dedicated person before being used. Sanitary protection requirements for the transportation of unsealed sources for well logging 6
6.1 When transported outside the oil field, the packaging and transportation vehicle requirements shall comply with the relevant provisions of GB11806. 6.2 Special (concurrent) vehicles for testing and carrying radioactive materials must be equipped with safety devices and protective facilities for fixed source tanks, and can be interlocked with fixed objects on the vehicle.
The external radiation dose received by the driver should be less than the corresponding annual dose limit. The air kerma rate on the outer surface of the vehicle shall not exceed 25uGy·h, and shall not exceed 2.5μGy·h at 1m from the outer surface of the vehicle. 6.3 The tools for carrying or transferring radioactive sources must be flexible, easy to use, reliable in performance, and keep an appropriate distance between the radioactive source and the human body.
7 Protection monitoring
7.1 Personal dose monitoring shall be carried out in accordance with the provisions of GBZ128. 7.2 All containers of radionuclides and their outer packaging, storage and transportation equipment, shall be subjected to the measurement of gamma radiation level and surface radioactive contamination level before and after use.
7.3 Before and after each high-activity operation and on-site logging operation in the laboratory, the radiation level in the workplace and the radioactive surface contamination of equipment and places must be measured. If necessary, the concentration of radioactive aerosols in the air should be measured. 7.4 When the experimental and logging operators leave the laboratory or the site after work, the radioactive contamination level of their exposed skin, work clothes and personal protective equipment must be measured. If contamination is found, it must be handled immediately and properly. 5 In general, the laboratory radiation level and the radioactive contamination level of equipment, ground and wall surfaces are comprehensively monitored once a month. 7.5
5 Environmental dose monitoring shall be carried out in accordance with the provisions of GB8703. 7.6
A1 Handling principles
a): Take decontamination measures as soon as possible:
Appendix A
(Informative Appendix)
Principles and emergency measures for handling radioactive contamination accidents Prepare appropriate decontamination reagents:
c) Select reasonable decontamination methods to prevent cross contamination and expansion of contamination:
c) Properly handle waste and waste liquid;
e): Wear effective personal protective equipment:
e) Record the accident process and handling situation in detail, and keep the files properly. A2 Emergency handling measures
General contamination accidents
A2.1.1 Liquid radioactive material spills and leaks can be dried with absorbent balls or absorbent paper. Powdered radioactive material can be removed with adhesive tape or wet rags, and then carefully washed with warm water. To prevent the spread of contamination, the decontamination procedure should start from the lightly contaminated surroundings to the heavily contaminated areas.
A2.1.2 If the effect of repeated cleaning is not obvious, effective decontamination agents can be selected for further decontamination according to the chemical properties of the radionuclides and the properties of the contaminated surface.
A2.2 Serious contamination accidents
A2.2.1 Immediately notify other personnel on the scene, and quickly mark the scope of contamination to prevent other personnel from entering the contaminated area. A2.2.2 When the skin or wound is contaminated, it should be cleaned immediately; when the eyes are contaminated, they should be rinsed with water immediately; if radioactive substances may enter the body, medical personnel should be notified immediately, and emergency measures should be taken in time if necessary. A2.2.3 After taking necessary measures to reduce hazards and prevent the spread of contamination, personnel in the contaminated area should take off contaminated clothes and leave them in the contaminated area and leave the area immediately. bzxz.net
A2.2.4 After the accident occurs, the person in charge of protection and the supervisor should be notified as soon as possible, and the relevant supervisory and management departments should be reported immediately. The protection personnel should quickly propose a comprehensive plan to deal with the accident and assist the supervisor in organizing its implementation. After the contaminated area has been decontaminated and monitored, work can resume only with the approval of the protection personnel.
A2.2.5. Record the accident process and handling situation in detail as a basis for finding the cause of the accident, improving protection work, and identifying health conditions. A3 Commonly used decontamination reagents and methods
Commonly used decontamination reagents and methods are shown in Table A1. Table A1
Surface types
Glassware
Porcelain products
Decontamination reagents
Soap, detergent
Chromic acid mixture, citric acid, hydrochloric acid
Commonly used decontamination reagents and methods
Operation method
Brush and rinse with water
Place the vessel in a 3% hydrochloric acid and 10% citric acid solution and soak for 1 hour, then take it out. Wash with water, then put it in washing liquid (i.e. saturated solution of potassium dichromate in concentrated sulfuric acid) for a while, take it out and rinse with water
Concentrated hydrochloric acid is not suitable for carbon-14,
iodine-131, etc.
Surface types
Clothing
Metals
Paints
(including lacquer)
Rubber products
Decontamination reagents
Remove the surface||t t||Soap or washing powder
Citric acid, oxalic acid
Cut and repair
Soap or detergent
9%~18% hydrochloric acid or 3%~6% sulfuric acid solution
Citric acid or dilute nitric acid
Heating method
3% ammonium citrate aqueous solution or 10% phosphoric acid
Sodium aqueous solution or 10% EDTA solution
10% dilute hydrochloric acid||tt| |Ammonium citrate
Acid or carbon tetrachloride
Water, warm water, steam, detergent
3% citric acid or oxalic acid solution
1% sodium phosphate aqueous solution
Organic solvent or sodium hydroxide or potassium hydroxide
Concentrated potassium hydroxide solution
10% dilute hydrochloric acid
Scraping (cutting) method
Dilute nitric acid
Continued Table A1
Operation method| |tt||Use tools to plane off a few millimeters of the surface
When the pollution is greater than 1000 pulses/min, wash it with a washing machine. If the pollution is less than 1000 pulses/min, wash it with general methods
Wash it with a washing machine if the pollution level is high
Cut off the contaminated parts for waste disposal, and then patch them with cloth. General soaking and wiping washing method
First wet the surface, then brush it, and finally rinse it with water. Soak the stainless steel in 10% citric acid solution for 1 hour, then rinse it with water, then soak it in dilute nitric acid for 2 hours, and then rinse it with water. Act in a heated 10% nitric acid solution for about 15 minutes, and then brush it with 10% hot oxalic acid solution or 10% sodium hydroxide solution or 0.5% ammonia silane fluoride (NH, SiFa) solution. Scrub it and rinse it with clean water
Scrub it and rinse it with clean water
Dilute it with an organic solvent such as kerosene and brush it||tt ||Brush with its diluted solution
Rinse the contaminated area
Gradually dissolve and remove the paint
General cleaning
Wash and rinse
When general decontamination still does not meet the
requirements
Nylon is suitable for citric acid, and adhesive
Glue and kapok are suitable for oxalic acid
Applicable to local severe
The effect is not good, suitable for low
Most metals cannot be immersed
There is obvious damage to the surface:
Applicable to stainless steel
Good effect
Surface damage
Steam decontamination effect is better,
can reach 50%~90%
Cannot be used for paint on lead
Cannot be used for varnished cloth
Applicable to local pollution
Not applicable to carbon-14, iodine-131
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