GBZ 124-2002 Radiation protection standard for geothermal water applications

This standard specifies the control level and test method for radon (222Rn) in geothermal water (including hot spring water). This standard applies to the development and utilization of geothermal water. GBZ 124-2002 Radiation Health Protection Standard for Geothermal Water Applications GBZ124-2002 Standard Download Decompression Password: www.bzxz.net

Ics13.100
National occupational health standard of the People's Republic of China GBZ124-2002
Radiological protection standards for using geothermal water2002-04-08 IssuedwwW.bzxz.Net
Ministry of Health of the People's Republic of China
2002-06-01 Implementation
Normative references
Terms and definitions
Control level
Test methods
Radiological health requirements for ammonia spring baths
Appendix A (informative appendix)
Rapid determination method for 22Rn in water
Scintillation radiant gas method
This standard is formulated in accordance with the "Law of the People's Republic of China on the Prevention and Control of Occupational Diseases". If the original standard GB16367-1996 is inconsistent with this standard, this standard shall prevail.
Chapter 4 of this standard is mandatory, and the rest is recommended. Appendix A of this standard is an informative appendix.
This standard is proposed and managed by the Ministry of Health.
The drafting unit of this standard: Institute of Radiation Medicine, Chinese Academy of Medical Sciences. The main drafters of this standard: Wang Xiehua and Hao Jun. The Ministry of Health is responsible for the interpretation of this standard.
1 Scope
Radiation Health Protection Standard for Geothermal Water Applications GBZ124-2002
This standard specifies the control level and inspection method for hydrogen (222Rn) in geothermal water (including hot spring water). This standard applies to the development and utilization of geothermal water. 2 Normative References
The clauses in the following documents become clauses of this standard through reference in this standard. For any dated referenced document, all subsequent amendments (excluding errata) or revised versions are not applicable to this standard. However, the parties to 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.
GB8538.58
GBZ/T155
3 Terms and definitions
Method for determination of hydrogen in drinking natural mineral water Scintillation vial method for determination of hydrogen concentration in air The following terms and definitions apply to this standard. 3.1 Geothermal water
Groundwater extracted from artificial boreholes deep underground or naturally gushing out to the surface. 3.2 Hydrogen spring bath
Therapeutic bathing with geothermal water or hot spring water with a hydrogen concentration greater than 110 kBg·m 4
Control level
For geothermal water used for drinking and living in residences, the control level of hydrogen concentration in the water is 50kBg·m34.1
4.2; for geothermal water used for production in factory workshops, the control level of hydrogen concentration in the water is 100kBg·m3. 4.3 When the hydrogen concentration in geothermal water for medical use exceeds 300kBg·m, medical personnel should take corresponding protective measures when entering the bathing room.
4.4 In all practices related to geothermal water application, the control levels of hydrogen and hydrogen progeny in the air at different locations are listed in Table 1:
Application location
Residential and workshop
Balamitherapy room
5Testing method
Table 1 Control levels of hydrogen and hydrogen progeny in the air at different locations Equilibrium equivalent hydrogen concentration
ECRn,Bq·m3
Hydrogen progeny
10-7J·m3
5.1 Regularly measure the concentration of hydrogen and hydrogen progeny in water and air at various locations. 5.2 For the monitoring method of hydrogen in air, see GBZ/T155. 5.3 For the monitoring method of hydrogen in water, see GB8538.58, and Appendix A (informative appendix) can also be used for reference. 6 Radiological health requirements for hydrogen spring baths
6.1 Hydrogen spring baths can only be implemented with prescriptions made by experienced physiotherapists. 6.2 Healthy people should not take hydrogen spring baths for recuperation. Children and pregnant women should be cautious in taking hydrogen spring baths. 6.3 Medical personnel entering the hydrogen spring bath treatment room should adopt simple and feasible radiation protection measures, such as strengthening ventilation, controlling working hours, and equipping with personal protective equipment. A1 Method Summary
Appendix A
(Informative Appendix)
Rapid determination method of 22Rn in water - scintillation gas method Take 100mL of water sample and seal it in a diffuser. Use an electric degassing pump to transfer 222Rn in the water to the scintillation chamber. Strictly follow the procedures of degassing, waiting, and determination to complete the test process. Use the value after the instrument is scaled to calculate the concentration of 222Rn in the water.
A2 Instruments and Equipment
Scintillation hydrogen analyzer.
Cylindrical scintillation chamber, volume 250mL.
A2.3 Electric degassing pump.
A2.4 Organic glass sampler (diffuser) with volume scale. A2.5 Drying tube with a volume of 4mL, equipped with color-changing silica gel for drying and two layers of ultra-fiber filter membrane. A2.6
Measurement system pipeline, volume 30mL.
A3 Test steps
A3.1 Sampling with a sampler with a volume scale, correctly take 100mL of water sample, then seal it and immediately connect it to the measurement system (see figure), open the inlet and outlet pistons to connect with the scintillation chamber in the instrument, start the electric degassing pump, and force air to blow for 3 minutes to transfer the 22Rn in the water sample to the scintillation chamber that has been cleaned with aged air beforehand after drying and removing the hydrogen daughters. A3.2 Determination After 22Rn is pumped into the scintillation chamber, wait for 5 minutes, then connect the LCD digital recorder, and measure for 10 minutes (5th to 15th minute) under the same conditions as when the instrument was calibrated (decay time, pipeline volume, measurement time correction), and calculate the concentration of 222Rn in water by net count. Determination system diagram
1—Scintillation hydrogen analyzer: 2—Electric degassing pump: 3—Sampler (diffuser); 4—Drying tube: 5—Scintillation chamber; A~H—Valve A4 Calculation of 22Rn concentration in water
A4.1 The activity of 22Rn used for calibration is calculated by formula (A1). CRnstandard=QRa（1-e*t）
Activity of 222Rn for calibration, Bq;
Where: CRnstandard—
Activity of liquid 226Ra source for calibration, Bq: 22Rn decay constant, d;
t222Rn accumulation time, d.
Calculation of instrument calibration value K.
K=CRnstandard·/nstandard
Where: K
Instrument calibration value, Bq/cpm;
CRnstandard
Activity of 22Rn generated by liquid 226Ra source, Bq: Net count measured by 22Rn for calibration, cpm;
Volume correction factor.
A4.3 Calculation of 222Rn content in water.
CRnwater=K·nwaterN
Wherein: CRnwater=
Vwater=
22Rn concentration in water sample, Bq/L;
-instrument scale value, Bq/cpm;
net count of water sample measured at the specified time, cpm; total volume of water sample, L.
A4.4 Precision
The difference between the results of two parallel samples should not exceed 20%. (A1)
（A2)
（A3)
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