Uranium GB 14586-93 National Environmental Protection Agency 1993-08-14 approved 1994-04-01 implementation 1 Subject content and scope of application This standard specifies the procedures for the decommissioning of uranium mining and metallurgy facilities, environmental impact assessment, and general requirements for environmental remediation engineering design, construction, acceptance, and environmental management. This standard applies to all decommissioned uranium mining and metallurgy facilities. For non-uranium mining and metallurgy facilities, the radioactive material content exceeding the relevant standards shall be referred to the implementation. 2 Reference standard GB 8703 radiation protection regulations EJ 432 uranium mining and metallurgy radiation environmental monitoring regulations 3 terms 3.1 Uranium mining and metallurgy facilities Sites, equipment, structures, buildings and other facilities that are engaged in uranium mining and smelting in a certain scale, including: a. Experimental facilities and sites that receive more than 10 kg of uranium per year from natural ore; b. To evaluate pits and wells for uranium deposits; c. Uranium mine d. Uranium smelting plant; e. Radioactive waste treatment system. 3.2 Decommissioning Remediation of permanently terminated uranium mining and metallurgical facilities to protect workers and the public from residual radioactivity and other possible hazards. 3.3 Waste disposal The solid waste is placed in the tailings pond, waste rock yard, goaf or other given location and processed and no longer retrieved. Disposal also includes controlled emissions of waste gas and wastewater to the environment. 3.4 Stabilization It is a planned action to carry out necessary treatment and disposal of waste rock yards and tailings ponds to maintain long-term stability and prevent the loss of collapse due to natural forces or other causes, resulting in environmental pollution accidents. 3.5 Security Analysis Analysis and calculation of risks related to an activity to be implemented. 3.6 waste rock Material shipped from a pit (well). include: a. Basic gangue free of uranium and thorium ; b. Low-grade uranium and plutonium materials with no recovery value. 3.7 tailings (slag) This refers to: a. The waste portion produced during the beneficiation process; b. Waste after heap leaching of ore; c. The ore and slime that were abandoned after the uranium hydrometallurgical plant leached uranium. 3.8 tailings pond (tailing pond) Special facilities for sedimentation and storage of ore and slime in the tailings slurry of the water and metallurgical plant. 3.9 氡 precipitation rate The amount of strontium that is deposited into the air through the unit area interface during a unit time interval. 4 Decommissioning Environmental Management Procedures Environmental management procedures for the decommissioning of uranium mining and metallurgical facilities include: a. File an application for retirement; b. Prepare a governance plan, and prepare an environmental pre-assessment report and approve it; c. Organization design and implementation; d. Project completion acceptance; e. Transfer and long-term monitoring of decommissioned facilities. 5 Application and approval 5.1 The uranium mining and metallurgy facilities shall submit a report on the application for decommissioning to the competent department before the final production. The whole process of decommissioning shall be completed within three years. 5.2 Application report for facility decommissioning: 5.2.1 Provide the name, nature, type, size, length of service and reasons for decommissioning and the time of termination of the decommissioning facility. 5.2.2 Provide the types, quantities, total radioactivity, specific activity and non-depleting substances and content of the remaining pollution sources after the facilities are decommissioned and decontaminated. 5.2.3 Describe the pollution levels of contaminated structures and production sites. 5.2.4 According to the decontamination treatment of the decommissioned facilities and the compliance status after remediation, the decommissioning is unrestricted or restricted. It also describes its impact on the environment and conducts safety analysis. 5.3 When the facility decommissioning unit submits the application for decommissioning of the facility to the competent department, it shall submit a decommissioning plan and optimize the proposed plan. 5.4 After receiving the report on the application for decommissioning of the facility, the competent department shall promptly organize experts to conduct the demonstration and approval of the facility decommissioning report and the environmental remediation plan. 5.5 Entrust the unit with evaluation qualification to prepare the environmental impact report, and report it to the national environmental protection administrative department for approval after being pre-examined by the competent department. 6 implementation 6.1 Disposal of contaminated equipment Contaminated equipment, tools, steel scrap decontamination process must be carried out until the non-fixed α, β radioactive contamination of the surface of the standard requirements of the relevant regulations. 6.2 Mine 6.2.1 The pits and wells of the decommissioned mines, the patio openings to the surface, and the wind shafts must be permanently sealed to ensure that they are closed, strong, secure, and non-leakage. After the pits and wells are closed, the earth and stone are thickened and compacted. Restore the landscape to prevent natural collapse and vandalism. 6.2.2 For areas where collapse and caving may occur, permanent buildings shall be demolished, and waste rock masonry columns shall be supported for areas that are not allowed to fall, and surface collapse and collapse shall be controlled. 6.2.3 Effective measures should be taken for mines that may have sewage to prevent pollution. 6.3 Open pit mining 6.3.1 The slope of the open pit should be stabilized to prevent sheeting and landslides. 6.3.2 For the surrounding areas with large height difference on the slope, it is necessary to build a wall and set a permanent no-entry sign to prevent humans and animals from entering the city and posing danger. 6.3.3 When the average value of the radon exhalation rate on the surface of the open-pit mine ruin exceeds the limit specified in A2 of Appendix A, the vegetation shall be covered to reduce the precipitation of radon. 6.3.4 If the surface structure adopts the decontamination treatment measures and still fails to meet the requirements of 10.1.2, it shall be properly disposed of according to the requirements of radioactive waste. 6.4 Land immersion site Decommissioning of in-situ mining must restore mine water to acceptable water quality standards and prevent contamination of groundwater and surface water. 6.5 Seminating plant 6.5.1 For the decommissioning of the smelting plant, the ground of the contaminated floor, floor and building shall be removed in accordance with the requirements of 10.1.2 and A3 of Appendix A, and these wastes may be buried in the tailings pond. 6.5.2 Decommissioned heap leaching sites must be stacked in the tailings pond or covered with suitable materials and disposed of properly. 6.5.3 Sites contaminated by ore heaps must be removed and, where necessary, detectors can be used to detect buried burial contaminants and remove them until the surface residual pollution is reduced to an acceptable level. 6.6 Waste Stone Field 6.6.1 A stone dam should be built in the waste rock site to prevent the loss of waste rock landslide. 6.6.2 Set up flood control ditches around the waste quarry to prevent floods from rushing into the waste quarry. 6.6.3 When the average value of the surface decantation rate of the waste rock yard exceeds the limit specified in A2 of Appendix A, the covered vegetation shall be carried out. 6.7 tailings pond 6.7.1 For the decommissioning of tailings ponds, the precipitation rate and gamma radiation level of radon should be lower than the specified limits, and the collapse of the dam body, the loss of tailings, and the seepage of water will pollute the environment. 6.7.2 When the tailings pond is decommissioned, the concave land in the reservoir should not be retained, and it can be filled with soil or waste rock. The top of the reservoir should be flattened to a slope of 2% to 4% before covering the vegetation. In slopes without dams, slopes with a slope of 1:3 to 1:5 should be built, and stone slopes should be used to form slopes with a thickness of 50-100 cm. The requirements for stabilization must be met and flood discharge and seepage recovery facilities should be retained. 6.7.3 Covering tailings should be properly selected according to local conditions. The thickness of the covering should meet the requirements of A2 in Appendix A and prevent wind erosion, rain erosion and tailings loss. 7 Project completion acceptance 7.1 After the completion of the facility decommissioning project, it shall be monitored in accordance with the requirements of EJ 432. The purpose of monitoring is to: a. Evaluate whether the facility decommissioning project meets the requirements for radioactive waste disposal issued by the state and relevant departments, and whether the environmental impact report is in compliance with the actual situation. b. Timely discovering possible events and ways to pollute the environment. c. Provide data for the acceptance and delivery of the facility. 7.2 When submitting the completion report of the facility decommissioning remediation project, the assessment report on the status quo of the facility decommissioning environment shall be submitted to the relevant competent department. 7.3 After receiving the project completion report and environmental status assessment report, the competent department shall be responsible for reviewing and accepting the environmental protection measures and project quality of the facility decommissioning with the local government organization experts. 8 Transfer and long-term monitoring of decommissioned facilities 8.1 When the facility is decommissioned and delivered to the place, the decommissioning unit must submit the completion report and the environmental status assessment report to the receiving unit. The receiving unit shall conduct supervisory monitoring within one year after receipt, and formal transfer procedures when it is confirmed that the decommissioning environmental management standard is met. After that, the receiving unit is responsible for long-term supervision. 8.2 Decommissioned facilities must be monitored and managed on a permanent basis. The main contents include: a. Waste rock yard and tailings pond to avoid exposure; b. The closed isolation system used can effectively prevent groundwater and surface water from being contaminated by radionuclide migration; c. Precipitation of waste in waste rock and tailings; d. The effects of radioactive dust and gamma radiation. 8.3 The environmental monitoring and evaluation report after the handover of decommissioning facilities shall be prepared by the relevant local departments. 9 Quality Assurance 9.1 In order to ensure the long-term stability of the quality of decommissioning projects, in the preparation of the decommissioning project plan, the quality assurance program for decommissioning projects shall be prepared, and the design and construction units shall be required to formulate specific measures for quality assurance. 9.2 The design of major decommissioning projects shall be entrusted to the units with design qualifications, and the design must meet the requirements of the approved environmental impact report. The construction design must be reviewed and approved by the higher authorities before construction. 9.3 The application report, decommissioning plan, design, construction, acceptance data, environmental monitoring data, environmental impact assessment report and related quality assurance documents for decommissioning of the facility shall be archived and permanently stored. 9.4 The design department and the facility decommissioning unit shall inspect and supervise the construction quality, and find that the quality problem shall be resolved within a time limit. 10 Environmental Management Standards 10.1 The radiation dose limits for decommissioning of facilities must meet the public and environmental requirements of GB 8703. 10.1.1 After the final decommissioning of the facility, taking into account the characteristics of the environment and the social and economic conditions, the additional exposure dose of the decommissioning facility to the surrounding residents shall be limited to the lifetime average annual effective dose equivalent limit specified for it. The appropriate portion of the value and a sufficient share for other possible exposures. 10.1.2 After decontamination treatment of contaminated equipment, equipment, buildings, etc., when the non-fixed α, β radioactive surface pollution degree is ≤0.08Bq/cm 2 , after the monitoring of the protection department, it can be used in general industry. Use (except food industry). 10.1.3 After the contaminated waste steel has been cleaned and decontaminated, the surface pollution degree limit that can be used without restriction is as specified in Appendix A, A1. 10.1.4 After the final disposal of waste rock yard, tailings pond, heap leaching, in-situ immersion and open-air ruins, the average surface 氡 precipitation rate limit is shown in Appendix A, A2. 10.1.5 After land decontamination and remediation, the maximum specific activity limit of nuclide ra-226 in different depth soils is specified in Appendix A, A3. 10.1.6 When the effluent from the mine, waste rock yard, tailings pond, heap leaching, in-situ immersion, open-air ruins and other facilities after the final disposal flows into the environment, the radioactive materials cause the key groups to receive one year. The dose should be in accordance with the provisions of 10.1.1. 10.2 Non-radioactive emission standards for toxic and hazardous substances shall be implemented in accordance with relevant state regulations. Appendix A Environmental management limits (reference piece) Partial environmental management limits from the International Atomic Energy Agency (IAEA) Safety Series No. 85 and the Principles of Exemption Management for Radiation Sources and Practices: A1 contaminated waste steel after cleaning and decontamination, its α, β radioactive surface pollution degree is less than 0.04Bq / cm 2 , can be used without restrictions. After the final disposal of A2 waste rock yard, tailings pond, heap leaching, in-situ immersion and open-air ruins, the average surface enthalpy precipitation rate should not exceed 0.74 Bq/m 2 ·S. A3 The highest specific activity requirement for the radioactive radium-226 after land decontamination and remediation: in the average range of 100m 2 , the average value of the upper 15cm soil layer is 0.18Bq/g; the average value below the 15cm thickness soil layer is 0.56 Bq/g. A4 Decontamination of habitable buildings requires that the highest concentration of scorpion (including background) should be as high as 4.16 × 10 -7 J / m 3 (0.02 WL), but not more than 6.24 × 10 —7 J/m 3 (0.03 WL). Additional information: This standard was proposed by the National Environmental Protection Agency. This standard was drafted by the Ministry of Mines and Metallurgy of China National Nuclear Corporation and the State-owned 272 Factory. The main drafters of this standard are Xiao Baojian, Pan Yingjie, Sang Shiqin, Zeng Zhaoli, and Li Lejie. This standard is interpreted by the National Environmental Protection Agency. 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