Classification and classification criteria for radioactive waste
Classification and grading guidelines for radioactive waste 1 Subject matter and scope of application This standard specifies the classification and grading guidelines for radioactive waste. This standard applies to all radioactive waste produced during the production, research and use of radioactive materials, as well as during processing, conditioning, and decommissioning. This standard does not apply to uranium, thorium and their associated waste generated during the Mineral Ore, environmental management of such waste may refer. 2 Terminology 2.1 Radioactive waste For the purpose of auditing, radioactive waste is contaminated with radionuclides or radionuclides, and its concentration or activity is greater than the level of cleansing and control specified by the national regulatory authority, and is expected to be no longer used. substance. 2.2 Radioactive gaseous waste A gaseous waste containing radioactive gases and aerosols whose radioactive concentration exceeds the emission limits specified by the national regulatory authority. 2.3 radioactive liquid waste A liquid waste containing radionuclides whose radioactive concentration exceeds the emission limits specified by the national regulatory authority. 2.4 Radioactive solid waste A solid waste containing radionuclides whose radioactive specific activity or pollution level exceeds the level of cleansing and control specified by the national regulatory authority. 2.5 Exempt waste Waste containing radioactive material and whose radioactive concentration, radioactivity specific activity or pollution level does not exceed the level of cleansing and control specified by the national regulatory authority. 2.6 cleaning level A set of values ​​specified by the national regulatory authority, expressed in terms of radioactive concentration, specific activity of radioactivity and/or total activity. When the source of radiation is equal to or lower than these values, the control can be deactivated. . 3 Framework for the classification of radioactive waste 3.1 Wastes are classified into exempted waste, low-level radioactive waste, medium-level radioactive waste or high-level radioactive waste according to their level of radioactivity, as shown in Figure 1. Figure 1 3.2 Radioactive waste, classified into airborne waste, liquid waste and solid waste according to its physical properties. 3.3 Radioactive airborne waste is classified into different grades according to their radioactive concentration levels. The radioactive concentration is expressed in Bq/m3. 3.4 Radioactive liquid wastes are classified into different grades according to their radioactive concentration levels. The radioactive concentration is expressed in Bq/L. 3.5 Radioactive solid waste is first classified into five types according to the half-life length and emission type of the nuclides contained therein, and then divided into different grades according to their radioactive specific activity levels. The specific activity of radioactivity is expressed in Bq/kg. 4 Classification of radioactive airborne waste 4.1 Stage I (low emission): concentration less than or equal to 4 × 107 Bq / m3. 4.2 Class II (intermediate emission): concentration greater than 4 × 107 Bq / m3. 5 Classification of radioactive liquid waste 5.1 Level I (low level waste): The concentration is less than or equal to 4 × 106 Bq / L. 5.2 Level II (discharge in the middle): The concentration is greater than 4×10 6 Bq/L, less than or equal to 4×10 10 Bq/L. 5.3 Class III (high-level liquid waste): The concentration is greater than 4×1010Bq/L. 6 Classification of radioactive solid waste 6.1 The specific activity of the alpha emitter nuclide with a half-life of more than 30a in radioactive solid waste is greater than 4 × 106 Bq/kg in a single package (average alpha specific activity for multiple packaging at near-surface disposal facilities) The degree is greater than 4 × 105 Bq / kg) is alpha waste. 6.2 In addition to alpha waste, radioactive solid waste is classified into four types according to the half-life of the longest-lived radionuclide. 6.2.1 Wastes containing radionuclides with a half-life of less than or equal to 60 d (including nuclide iodine- 125) are classified as secondary according to their radioactivity specific activity levels. 6.2.1.1 Class I (low level waste): specific activity is less than or equal to 4 × 106 Bq / kg. 6.2.1.2 Level II (intermediate discharge): specific activity is greater than 4 × 106 Bq / kg. 6.2.2 Wastes containing radionuclides with a half-life greater than 60 d and less than or equal to 5 a (including nuclide cobalt- 60) are classified as secondary according to their radioactivity specific activity levels. 6.2.2.1 Level I (low level waste): specific activity is less than or equal to 4 × 106 Bq / kg. 6.2.2.2 Level II (intermediate discharge): specific activity is greater than 4 × 106 Bq / kg. 6.2.3 Wastes containing radionuclides with a half-life greater than 5a and less than or equal to 30a (including nuclide 铯 -137) are classified into three levels according to their radioactivity specific activity levels. 6.2.3.1 Class I (low level waste): specific activity is less than or equal to 4 × 106 Bq / kg. 6.2.3.2 Class II (intermediate discharge): Specific activity is greater than 4 × 106 Bq / kg, less than or equal to 4 × 1011 Bq / kg, and the heat release rate is less than or equal to 2 kW / m3. 6.2.3.3 Level III (high level waste): The heat release rate is greater than 2 kW/m3, or the specific activity is greater than 4×1011 Bq/kg. 6.2.4 Wastes containing radionuclides with a half-life greater than 30 a (excluding alpha waste) are classified into three levels according to their radioactivity specific activity levels. Soybean Conveying Welded Bending Plate Chain Soybean Conveying Welded Bending Plate Chain,Export Transmission Chain,Industrial Alloy Steel Roller Chain,Double Plus Conveyor Chain Changzhou Donghu Chain Transmission Technology Co., Ltd. , https://www.dhuweldingchain.com
6.2.4.1 Level I (low level waste): Specific activity is less than or equal to 4 x 106 Bq/kg. 6.2.4.2 Class II (intermediate discharge): specific activity is greater than 4 × 106 Bq / kg, and the rate of heat release is less than or equal to 2 kW / m3. 6.2.4.3 Class III (high level waste): specific activity is greater than 4 × 1010 Bq / kg, and the heat release rate is greater than 2 kW / m3.
7 The annual dose value of the exempted waste from exposure to public members is less than 0.01 mSv, and the collective dose to the public does not exceed 1 person·Sv/a of waste containing very few radionuclides. Appendix A Main factors to be considered in the development of a radioactive waste classification system (Reference) A1 The main objectives of establishing a classification system include: a. Types of radioactive waste to be included; b. Activities and facilities to be considered; c. Areas of application (after planning, operation, and operation); d. Safety objectives to be met. The scope of the A2 classification system includes: a. exposure to staff; b. exposure to members of the public; c. impact on the environment; d. nuclear criticality; e. normal operation, accident or emergency conditions; . Heat release from radioactive waste; g. Process and engineering issues; h. Information exchange. A3 Regulatory and technical constraints, including: a. Radionuclide composition and concentration of radioactive waste; b. Limits and requirements specified by the regulatory authority; c. Pathways and scenarios proposed by safety assessment; d. e. Site conditions (for the disposal of radioactive waste, geological, hydrogeological and meteorological characteristics have an important impact on site selection and the type of radioactive waste that can be disposed of therein; f. Social and policy issues; g Legal provisions and requirements. A4 Radioactive waste parameters, including. a. source; b. nuclear criticality; c. radiological characteristics: half-life, heat release, intensity of penetrating radiation, activity and concentration of radionuclides, surface contamination and dose factors related to radionuclides; d. : physical state (solid, liquid or gaseous), size and weight, compactability, dispersibility, volatility, solubility and miscibility; e. chemical properties: potential chemical hazards, corrosion resistance, corrosivity, organic content , flammability, chemical reactivity, gas release and absorption of radionuclides; f. Biological characteristics: potential biological hazards. Additional notes: This standard was proposed by the National Environmental Protection Agency and China National Nuclear Corporation. This standard was drafted by the Second Research and Design Institute of the Nuclear Industry. The main drafters of this standard are Sun Donghui, Wei Kuizi and Yang Mu. This standard is interpreted by the National Environmental Protection Agency.