GB/T 23728-2026Technical regulation for radiation environmental impact assessment in uranium mining and milling (English PDF)

5.1 Evaluation Criteria

5.1.1 Dosage Limits The annual effective dose limit for the public should comply with the requirements of GB 18871.

5.1.2 Dosage constraints and control values

5.1.2.1 Public dose constraints shall comply with the requirements of GB 23727.Dose constraints may be determined based on the characteristics of the uranium mining and metallurgical project.

5.1.2.2 The effective dose control value for individuals in the event of a single incident/accident shall comply with the requirements of GB 23727.

5.2 Evaluation Scope

5.2.1 The scope of the radiation environmental impact assessment is usually centered on the emission point of the gaseous effluent that has the greatest impact on the surrounding residents, with a radius of 20 km. The area.

5.2.2 The groundwater environmental assessment area shall be determined based on the facility type and site hydrogeological conditions, with reference to the relevant requirements in HJ610.

5.3 Evaluation Factors

5.3.1 Evaluation factors for gaseous effluent during the construction phase include 238U, 234U, 230Th, 226Ra, 210Po, 210Pb, and 222Rn, etc., and for liquid effluent... Evaluation factors include 238U, 234U, 230Th, 226Ra, 210Po, and 210Pb.

5.3.2 The evaluation factor for gaseous effluent during the decommissioning phase is 222Rn, and the evaluation factor for liquid effluent is determined based on the decommissioning source items.

5.3.3 In the event/accident situation, the evaluation factors should be determined based on the accident source items.

5.4 Evaluation of Sub-region Division The evaluation sub-region is divided into concentric circles with radii of 1km, 2km, 3km, 5km, 10km, and 20km, centered on the evaluation center. The concentric circle is divided into 22.5° sector segments, with each sector starting at 11.25° to the left and right of due north, resulting in a total of 96 evaluation sub-regions.

5.5 Age Group Division They can be divided into four age groups. infants (1 year or younger); toddlers (1 year or older, 7 years or younger); and children (3 years or younger). 7 years old, less than or equal to 17 years old; Adult group. greater than 17 years old.

5.6 Evaluation Model

5.6.1 Atmospheric Dispersion Model An atmospheric dispersion model suitable for the local topography and meteorological characteristics should be used, and its applicability should be explained. Relevant dispersion models in HJ

2.2 can be used.

5.6.2 Surface Water Dispersion Model A surface water dispersion model suitable for the characteristics of the receiving water body should be used, and its applicability should be explained. Relevant dispersion models from HAD101/05 can be used. Model.

5.6.3 Groundwater Dispersion Model A groundwater dispersion model suitable for local hydrogeological conditions should be adopted, taking into account the project's characteristics, and its applicability should be explained. HJ610 can be used. Analytical or numerical solution dispersion models for groundwater.

5.6.4 Public Effective Dose Estimation Model Public effective dose estimation includes routes such as inhaled internal radiation, deposited external radiation, immersion external radiation, ingested internal radiation, and drinking water internal radiation. Effective individual and group doses for the general public. Appendix A provides recommended dose estimation models.

6.1.1 Meteorology

6.1.1.1 Select a surface meteorological station that is relatively similar to the terrain and meteorological characteristics of the project site, conduct a suitability assessment, and provide the name of the meteorological station. Name, number, distance, and orientation.

6.1.1.2 Collect statistical data on the main meteorological characteristics of the project site for no less than 20 years, and provide the average wind speed, wind rose diagram, and maximum wind speed. Parameters include speed, average annual temperature, extreme temperature, average annual relative humidity, average annual rainfall, extreme rainfall, and average annual evaporation.

6.1.1.3 Meteorological data for a relatively complete calendar year of the past five years should be collected according to the requirements of the atmospheric dispersion model, which can be done in accordance with HJ2.2. The relevant requirements of the Chinese side were investigated.

6.1.2 Surface water Investigate and provide monthly flow, river width, flow velocity, river depth, and hydraulic gradient of the directly receiving water body through data collection or self-measurement. The location and monthly flow of the tributary downstream of the discharge outlet that flows into the receiving water body.

6.1.3 Groundwater Based on the requirements of the groundwater dispersion model and combined with existing exploration and investigation data, the site can be investigated in accordance with the relevant requirements of HJ610 to determine the location of the project. The region's aquifers are divided, and parameters such as groundwater recharge and drainage conditions, flow direction, thickness, permeability coefficient, hydraulic gradient, and effective porosity are considered.

6.2.1 Land use and water use

6.2.1.1 Collect land use status and planning data within a 5km radius of the evaluation center for the past 5 years, and provide the land use type.

6.2.1.2 Through data collection and on-site investigation, investigate and evaluate the water environment function of the receiving water body, the location of the water intake, and the water intake volume within the evaluation scope. For centralized drinking water intakes, specify the water supply volume and supply area; for irrigation water intakes, specify the irrigated area, irrigation water volume, and irrigation... Irrigation methods, crop types, and their yields, etc.

6.2.1.3 Investigate the location, aquifer, and water intake volume of centralized drinking water and irrigation water intakes within the groundwater assessment area, and provide... The relationship between domestic and irrigation water and groundwater related to the project.

6.2.2 Population

6.2.2.1 The population distribution in any one of the past five years within the scope of the survey and evaluation was investigated by combining data collection and on-site investigation.

6.2.2.2 Provide the names, population, and locations of natural villages (groups) within a 5km radius of the evaluation center (3km radius for decommissioned projects). For the population... Densely populated areas can be organized by administrative villages; the population size of each age group in the evaluation sub-region is given, along with the population size of each age group in the evaluation sub-region for different uses of the receiving water body. Population size, the proportion of residents in each age group to the total population, and the natural population growth rate of the county (city, district) where the site is located; predicted evaluation year. Evaluate the population size of each age group in the sub-region.

6.2.3 Diet and Habit Survey

6.2.3.1 In conjunction with the irradiation pathway, conduct diet and habit surveys using data collection or on-site sampling and statistical methods.

6.2.3.2 Provide the annual consumption of animal products, agricultural products, and aquatic products for each age group of residents, and explain the share of food from the evaluation sub-region; animal... Products include poultry, beef, mutton, pork, eggs, and dairy products; agricultural products include grains, fruits, and vegetables; and aquatic products include fish and invertebrates. Classes, etc.

6.2.3.3 Provide the annual time share of indoor and outdoor activities and water use (shore activities, swimming and boating) for each age group of residents.

9.4 Dosage Evaluation

9.4.1 Calculate the effective public dose for each evaluation sub-region and age group based on the superposition of different radiation pathways, and provide the key resident groups, key nuclides, and related factors. Key irradiation pathway. Evaluation conclusions drawn.

9.4.2 Calculate the collective dose to the public at different distances from which each irradiation pathway is superimposed within the evaluation range.

10.2 Evaluation of the Consequences of Typical Events/Accidents

10.2.1 Failure of waste gas treatment facilities Predict the location of the maximum ground-level concentration of nuclides, the concentration of nuclides in the air, and the concentration of nuclides in surface deposits, taking into account inhalation internal irradiation and plumes. Immersion external radiation and surface sediment external radiation are used to provide the maximum effective dose for individuals in the public during the failure period.

10.2.2 Wastewater treatment facility failure/process tank/reservoir leakage Predict the nuclide concentration at the first water intake downstream of the discharge outlet, considering both internal radiation in drinking water and external radiation from water immersion, and give the causes during the failure period. Maximum effective dose for the general public.

10.2.3 Tailings (slag) dam failure

10.2.3.1 Predict the nuclide concentration in the downstream water bodies of the flood-inflowing surface water, considering internal radiation from drinking water and external radiation from water immersion, and provide the flood... Effective dose to the individual public in the evaluation sub-region during the discharge period.

10.2.3.2 Predict the radon concentration in the air of each evaluation sub-region, considering internal irritation from radon (including progeny) inhalation, and provide the evaluation results for each sub-region during the accident handling period. Effective dose for individuals in the district.

10.2.3.3 Calculate the effective dose to the public for each evaluation sub-region and age group under different irradiation pathways, and give the maximum effective dose to the individual public.

10.2.4 Evaporation pond/tailings (slag) dam leakage

10.2.4.1 Predict the migration distance, range of influence, and concentration distribution of nuclides.

10.2.4.2 When there is a water intake point within the groundwater influence area, predict the radionuclide activity concentration at the water intake point and estimate it based on the water use pattern. Effective dose for the general public.

10.2.5 Dosage Evaluation Evaluate whether the maximum effective dose to an individual in the public during the most credible event/accident meets the dose control requirements. GB/T 23728-2026. Technical Specif...