GBZ 139-2002 Standard for Radiation Health Protection in Rare Earth Production Sites
Some standard content:
Ics13.100
National occupational health standard of the People's Republic of China GBZ139-2002
Radiological protection standards for the production places of rare-earth elements2002-04-08Promulgated
Ministry of Health of the People's Republic of China
Implementation on 2002-06-01
Normative reference documents
Basic requirements for radiological health protection in radioactive workplaces in rare-earth production and their classification
Site monitoring and dose estimation
Health management objectives of radioactive workers in rare-earth production
Appendix A (Normative Appendix) Derived air concentrations of relevant radionuclidesAppendix B (Informative Appendix) Dose estimation method2
This standard is formulated in accordance with the "Occupational Disease Prevention and Control Law of the People's Republic of China". This standard is Chapters 3 to 7 and Appendix A are mandatory contents, and the rest are recommended contents. This standard refers to the International Atomic Energy Agency Safety Series No. 115 "International Basic Safety Standards for Ionizing Radiation Protection and Safety of Radiation Sources" (1997), my country's national standard "Basic Standards for Radiological Health Protection" (GB4792-84), "Radiation Protection Regulations" (GE8703-88) and their revised versions to be submitted for approval, which are related to the exemption of radionuclides and their applications, toxicity groups and classification of open workplaces, and combined with my country's national conditions, to determine the basis for the division of radioactive workplaces in rare earth production, and put forward corresponding health protection requirements.
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 units of this standard: Institute of Radiation Protection and Nuclear Safety Medicine, Chinese Center for Disease Control and Prevention, Guangdong Provincial Institute of Radiation Protection and Baotou Municipal Health and Epidemic Prevention Station.
Main drafters of this standard: Chen Xing'an, Zha Yongru, Wu Moting, Xiao Huijuan and Cheng Yong'e. The Ministry of Health is responsible for the interpretation of this standard.
Scope 1
Radiation Health Protection Standard in Rare Earth Production Sites GBZ139-2002bzxZ.net
This standard specifies the classification of radioactive workplaces in rare earth production and the principles and basic requirements for radiation health protection. This standard applies to the protection of natural radionuclides and their daughters in rare earth ores in production sites such as rare earth mining, ore dressing, and smelting.
2 Normative References
The clauses of the following documents become clauses of this standard through reference in this standard. All subsequent amendments (excluding survey content) or revisions of dated referenced documents are not applicable to this standard. However, the parties to the agreement based on this standard are encouraged to study whether to use the latest versions of these documents. For all undated referenced documents, the latest versions shall apply to this standard.
GB4792
3 General Principles
Basic Standards for Radiation Health Protection
Health Standards for Radiation Workers
All rare earth production sites that involve radiation work must follow the basic principles of radiation protection such as justification of practice, optimization of protection, and limitation and restriction of personal doses, and follow the requirements of this standard. 4 Rare earth production radiation workplaces and their classification 4.1 Rare earth production radiation workplaces
Places engaged in rare earth production that meet one of the following conditions should be classified as rare earth production radiation workplaces. 4.1.1 The content of natural uranium and proton in rare earth materials is greater than one thousandth, and the maximum daily operating amount is greater than the following values: a) For rare earth mining, beneficiation, concentrate drying and smelting, the total amount of natural uranium and proton is 10kg. b) For ore fields, concentrate warehouses, and rare earth alloy warehouses, the total amount of natural uranium and proton is 50kg. 4.1.2 Although the content of natural uranium and thorium in rare earth materials is less than one thousandth and meets the general health protection conditions, the annual average concentration of uranium thorium dust and radionuclides related to the thorium system in the air of the production site is greater than one tenth of their respective derived air concentrations. For relevant radionuclides and their derived air concentrations, see Appendix A (Normative Appendix). 4.2 Classification of radioactive workplaces in rare earth production 4.2.1 Based on the daily equivalent maximum operating volume, the classification of radioactive workplaces in rare earth production is shown in Table 1. Table 1 Classification of radioactive workplaces in rare earth production
Maximum value of daily equivalent operating quantity, Bq
>4×10%
2×107~4×10%
<2×107
Note 1: The daily equivalent operating quantity of the radionuclide in the table is equal to the product of the actual daily operating quantity of the radionuclide (Bq) and the toxicity group correction factor of the nuclide divided by the correction factor related to the operating properties. 4.2.2 Natural uranium and natural needle are both poisoning group radionuclides, and their toxicity group correction factors are all 0.1. 4.2.3 The operating materials in the rare earth production process are solids with a low surface contamination level. The correction factors for their operating properties are shown in Table 2.
Table 2 Correction coefficients for nature of operation
Nature of operation
Dry dust-generating operation
Wet operation
5 Basic requirements for radiation health protection
Correction coefficient
5.1 Class A and Class B workplaces should have sanitary passage rooms and dedicated laundry rooms and be equipped with protective clothing, monitoring equipment and personal clothing storage cabinets, as well as monitoring equipment for skin, work clothes and carried-out items, flushing or shower facilities and storage cabinets for contaminated clothing.
5.2 The materials used for the interior decoration walls and floors of radiation workplaces should not be easy to accumulate dust and easy to decontaminate, and should be washed regularly. 5.3 A local exhaust and dust removal system should be used to maintain negative pressure inside. Local mechanical ventilation should be combined with comprehensive mechanical ventilation: and ensure that the ventilation frequency of workplaces of different levels shall not be less than the following requirements: Class A 6~10 times/hour
Class B 4~6 times/hour
Class C 3~4 times/hour
5.4 The dust-containing exhaust gas discharged from the workshop must meet the emission standards prescribed by the state: 5.5 The dust concentration of natural radionuclides such as uranium and thorium in the air of the radioactive workplace of rare earth production should be less than 2mg/m. 5.6 The holder of the rare earth production license shall provide the staff with personal protective equipment that is applicable, sufficient and meets the requirements of health protection.
6 Site monitoring and dose estimation
6.1 Site monitoring
a) The monitoring content of the radioactive workplace of dry dust generation operation in rare earth production should focus on the concentration of dust and hydrogen, gas and its short-lived daughters in the air, and the content of long-lived natural radionuclides in the dust. b) The monitoring contents of wet operation radiation workplaces in rare earth production should focus on the concentration of hydrogen, gas and their short-lived daughters in the air, gamma external irradiation and radioactive surface contamination. c) The monitoring contents of storage places for rare earth ores, concentrates, finished products, etc. should focus on the concentration of hydrogen, gas and their short-lived daughters and gamma irradiation.
6.2 Dose estimation
If necessary, dose estimation should be carried out based on the monitoring results. The estimation method is shown in Appendix B (Informative Appendix). 5
Use the dose conversion coefficient (dose caused by unit intake) given in Table B.1 to estimate the accumulated effective dose within 50 years after intake of proton, uranium and radium. In actual work, according to specific circumstances, the dose conversion coefficient of mine dust and proton and uranium compounds in different proportions can also be used to estimate the effective dose.
Health management of radiation workers in rare earth production 7.1 Radiation workers engaged in rare earth production should comply with the national requirements for personal dose monitoring and health management of radiation workers. The employer shall organize regular occupational health examinations before and during the post, and establish occupational health files. Personnel who have not undergone pre-employment occupational health examinations are not allowed to participate in radiation work. The content and requirements of occupational health examinations before and during employment shall be implemented in accordance with GBZ98 7.2
Appendix A
(Normative Appendix)
Derived air concentration of relevant radionuclides A.1 According to the different types of inhaled substances, the derived air concentration DAC of relevant nuclides for radiation workers is calculated according to the annual dose limit of 20mSv, see Table A.1. The maximum allowable concentration MPC dust containing uranium needle dust (slow absorption rate type) in the workplace air is 2.0mg/m
Table A.1 derives air concentration DAC
Nuclide j
Inhaled material type 2
DAC(Bq/m2)
0.72×10l
0.60×10-1
0.76×102
1.7×10-2
2.3×10-l
2.6×10-1
Note 1: The DAC values in Table A.1 are quoted from GB4792 and have been corrected for the annual dose limit, i.e., two-fifths. Note 2: Table A.1.The inhaled material types S, M, and F in 1 represent the classification of materials with slow, medium, and fast absorption rates in the lungs, respectively, which are equivalent to the Y, W, and D classifications in GB4792. A.2 For the implementation of Article 4.1.2, the following formula should be used to determine that those who meet the following conditions should be classified as radioactive workplaces: Cm dust
Zo.1DAC,*0
0.1MPCTh dust
Where:
Cj—the concentration of the relevant radionuclide j in the air listed in Table A.1, (Bq/m). CTh dust—the concentration of uranium needle dust in the air, (mg/m). DAC—the derived air concentration of the relevant radionuclide j listed in Table A1, (Bq/m)MPC dust—the maximum allowable concentration of uranium needle dust in the air, 2mg/m. 7
Appendix B
(Informative Appendix)
Dose estimation method
Conversion factors used when estimating doses in accordance with the requirements of Article 6.2. B.1
Radionuclide
Th mineral dustd
U mineral dustd
ITh:1Ud
3Th:1Ud
10Th:1Ud
Dose conversion coefficient for inhaled needles, uranium-series radionuclides or mineral dust (uSv/Bg)bType
Particle size AMAD (μm)
: The data in Tables B.1 and B.2 are from Radiation Protection from a
Thorium in Industrial Operations (Draft Safety Report NSRW-78) P.14-15, issued (internal) by the IAEA in October 1997b taken from the data for the occupational exposure reference person (nasal breathing 1.2m2/h) in the ICRP publication. Inhaled material type: S, M, F represent the categories of slow, medium, and fast absorption rates in the lungs, which are equivalent to the Y, W, and D categories in previous literature.
d expresses the dose μSv caused by 6 decays of 232Th and its daughters and 8 decays of 23u and its daughters per Bq of total a activity (assuming that 22Rn or 22Rn is not lost). For finely crushed and chemically treated ores, the above assumption is incorrect. AMAD activity median aerodynamic diameter, if this parameter is missing, can be used 5μm. e
2 When the exposure to hydrogen and gas progeny is large, the dose conversion factors in Table B.2 should be used to estimate the dose caused. Table B.2a Dose conversion factors for exposure to oxygen and gas progeny Dose conversion factor value
22Rn progeny
a Same as Table B.1 Note a
220Rn progeny
Dose conversion factor unit
mSv/(mJh/m2)
mSv/(WLM)
mSv/(mJ)
B.3 When the parameters of a specific substance are unknown, the basic assumptions for default parameters in Table B.3 can be used when calculating the committed effective dose after inhalation of needle-containing and uranium-containing dust.
Basic assumptions for default parameters in Table B.3
Default parameters
Radionuclide composition
Particle size (AMAD)
Absorption rate
Intestinal transfer factor
220Rn, 222Rn emissivity
Respiratory rate
Respiratory mode
Respiratory protection factor
Note 1: Cited from the same source as Table B.1, P15. Basic assumptions
232Th and 238U are both in equilibrium
S type is highly non-absorbent
For Th, 0.02%: For U, 0.2%
1.2m2/h (71% light exercise, 29% rest) Nose
The use of dust masks is not considered
Note 2: In the absence of site-specific data, the above assumptions should be used to convert intake into dose. Note 3: In most cases, the minerals of the needle have been processed and the needle can be considered to exist as a relatively difficult to absorb substance; but when the needle is subjected to a violent chemical reaction, such as the processing of monazite, the needle present is relatively easy to absorb. B.4 Calculation formula for total effective dose (cited from the same source as Table B.1, P65) If dose assessment is necessary, the total effective dose ET is calculated according to the following formula. Er=H,(d)+hRDlRD+hRnplRnp+hTnpITnP Where:
Hp(d)---Personal dose equivalent (mSv) from penetrating radiation received in that year:(B.1)
h---Accumulated effective dose due to unit exposure or intake. For radioactive dust, it should be calculated according to the dose conversion factor given in Table B.1: For hydrogen or gas progeny, it should be calculated according to the dose conversion factor given in Table B.2. I---Intake or exposure. For radioactive dust, Bq is used to represent the total α intake: For hydrogen or gas progeny, mJh/m is used to represent the exposure.
Footnote: RD refers to radioactive dust: RnP refers to hydrogen progeny: TnP refers to gas progeny. 92m2/h (71% light exercise, 29% rest) Nose
The use of dust masks is not considered
Note 2: In the absence of site-specific data, the above assumptions should be used to convert intake into dose. Note 3: In most cases, the minerals of the needles have been processed and the needles can be considered to exist as relatively difficult to absorb substances; but when the needles are subjected to violent chemical reactions, such as the processing of monazite, the existing needles are relatively easy to absorb. B.4 Calculation formula for total effective dose (cited from the same source as Table B.1, P65) If it is necessary to perform a dose assessment, the total effective dose ET is calculated according to the following formula. Er=H,(d)+hRDlRD+hRnplRnp+hTnpITnP Where:
Hp(d)---Personal dose equivalent (mSv) from penetrating radiation received in that year: (B.1)
h---Accumulated effective dose due to unit exposure or intake. For radioactive dust, the dose conversion factor given in Table B.1 should be used for calculation; for hydrogen or gas protons, the dose conversion factor given in Table B.2 should be used for calculation. I---Intake or exposure. For radioactive dust, Bq is used to represent the total α intake; for hydrogen or gas protons, mJh/m is used to represent the exposure.
Footnote: RD refers to radioactive dust; RnP refers to hydrogen protons; TnP refers to gas protons. 92m2/h (71% light exercise, 29% rest) Nose
The use of dust masks is not considered
Note 2: In the absence of site-specific data, the above assumptions should be used to convert intake into dose. Note 3: In most cases, the minerals of the needles have been processed and the needles can be considered to exist as relatively difficult to absorb substances; but when the needles are subjected to violent chemical reactions, such as the processing of monazite, the existing needles are relatively easy to absorb. B.4 Calculation formula for total effective dose (cited from the same source as Table B.1, P65) If it is necessary to perform a dose assessment, the total effective dose ET is calculated according to the following formula. Er=H,(d)+hRDlRD+hRnplRnp+hTnpITnP Where:
Hp(d)---Personal dose equivalent (mSv) from penetrating radiation received in that year: (B.1)
h---Accumulated effective dose due to unit exposure or intake. For radioactive dust, the dose conversion factor given in Table B.1 should be used for calculation; for hydrogen or gas protons, the dose conversion factor given in Table B.2 should be used for calculation. I---Intake or exposure. For radioactive dust, Bq is used to represent the total α intake; for hydrogen or gas protons, mJh/m is used to represent the exposure.
Footnote: RD refers to radioactive dust; RnP refers to hydrogen protons; TnP refers to gas protons. 9
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