GB 11929-2011Regulations for designing storage building of high level radioactive liquid waste (English PDF)

4.2 Storage Plant composition

4.2.1 Process Plant storage system components High level liquid waste storage plant process systems should include the following components.

a) high-level radioactive waste storage tanks and waste transportation equipment;

b) high-level liquid waste tank mixing system;

c) high-level radioactive waste liquid cooling system;

d) high-level radioactive waste storage tank dilution air and process exhaust aftertreatment system;

e) other auxiliary systems.

4.2.2 Storage Plant Building

4.2.2.1 concrete shielding equipment room High level liquid waste storage tanks and ancillary equipment with radioactive process used should be provided in sufficient thickness of the shield of reinforced concrete provided Preparation room.

4.2.2.2 Process trench and valve chamber Pipeline transportation of radioactive waste, the valve should be arranged in the pipe trench technology with shield and valve chamber.

4.2.2.3 cladding and liquid collection pit Radiological equipment room, valve chamber and process pipe trench should be lined by plane, and should be selected corrosion, irradiation, facing materials easy decontamination, the surface of the bottom cover Department should make certain slope and let drip hole at the lowest point.

4.2.2.4 Install the access area For installation, maintenance radiological equipment, installation and maintenance area should be set up.

4.2.2.5 Process control room and other ancillary buildings Including professional (water, heating, electricity, gas, etc.) buildings, gates and other health.

4.3 storage plant design principles

4.3.1 high level liquid waste storage plant shall be arranged in accordance with GB 18871 standards, the radiation in the workplace is divided into control and supervised areas, in order to In radiation protection management and control of occupational exposure, and in accordance with the EJ849, according to the level and extent of possible radiation contamination, and then control Area is divided into three sub-areas, namely green zone, orange zone and the red zone, white zone is supervised areas. The district should have a reasonable airflow and vacuum requirements, specific points District principles in Table 1.

4.3.2 high level liquid waste storage plant design should follow the principle of defense in depth. Wherein the multiple barriers including tanks and piping systems, equipment room Stainless steel cladding, concrete equipment room, building ventilation systems. Equipment room should be provided to withstand the weight of the entire structure, permeability and small Geotechnical radionuclides have higher adsorption capacity, to ensure the safety of the tank.

4.3.3 high level liquid waste storage building should be designed in accordance with the single failure criterion to ensure the reliability of the system, which assumes a system in any one Case of a single component failure can still correctly performing a predetermined system functions. Table 1 plant partition principle Regional Reference feature engaged in radiation work crowd control plant Supervised area (Usually no special Means of protection or security Regional measures, but need Often occupational exposures Article Member monitoring and evaluation) White areas (Non-radioactive work area) Is not in contact with radioactive plant Radioactive work area, generally Clean Staff generally do not enter this area Clothes need to be replaced Control area (Needs and may require Special protective measures or safety Region-wide measures) Green Zone (Operation radioactive work area) Class person staying in this area also Is safe, there appear soiled surface Pollution and aerosol pollution may , But timely detection and elimination The area between the entrance through the establishment of health Orange Area (Radioactive equipment maintenance area) District personnel are not often stay Field maintenance personnel subject to the anti-radiation Care professionals allowed to enter jobs Entering this zone should be subject to health personnel Air gates and gate Red Zone (Radioactive device area) Direct storage of radioactive materials Area, external radiation is usually Strong, serious pollution Usually people are not allowed to enter only after Too full decontamination, at a dose of personnel closely monitored Under Governor, to enter this area maintenance Ventilation System

4.3.4 Design of the plant shall be subject to the provisions of EJ/T 938's.

4.3.5 sump should set up an independent emergency cooling system in normal cooling water supply is interrupted, the waste to ensure that the temperature inside the tank is still below 60 °C.

4.3.6 should be set up within the plant emergency air pressure, ensure the normal air pressure inside the tank supply disruption hydrogen concentration in the air is still below the safety limit control 4.1% (volume percent).

4.3.7 should be set up within the plant emergency power to ensure external power supply is interrupted, the process cooling systems, instrumentation and control systems mainly normal operation Access channel and the control room and lighting needs.

4.4 tank equipment room

4.4.1 The equipment room design requirements

4.4.1.1 equipment room should be buried below ground.

4.4.1.2 equipment room should be lined with stainless steel cladding, should take the form of full-cladding. In order to ensure the construction quality of the cladding, the design should be regulated Given the quality of welding and weld cladding surface inspection requirements. Bottom cladding

4.4.1.3 equipment room should be made of a certain slope and let drip hole at the lowest point.

4.4.1.4 liquid collecting pit equipment room should be set at a waste transfer leakage and decontamination equipment waste equipment.

4.4.1.5 Design measures should be taken to prevent surface water or groundwater into the equipment room, cutting off all possible sources of the channel to prevent the tank being immersed Bubble and float. Inspection hole should be provided with sufficient equipment and emergency entrances case of an accident on the equipment room roof 4.4.1.6.

4.4.2 The equipment room testing requirements

4.4.2.1 liquid collecting pit equipment room should be set up signal level meter, signal meter should meet the requirements of multiple or diversity, in order to detect the sump leakage.

4.4.2.2 Equipment should be located aerosol detection apparatus.

4.5 storage plant maintenance

4.5.1 For large high-level waste storage tank (volume more than 100m3), time to consider the design overhaul, once the waste leakage should occur in a timely manner Down to spare slot.

4.5.2 In addition to large, high-level liquid waste tank, other process equipment, piping valves, meters and other measures should be overhauled or replaced have.

5.1 sump design requirements

5.1.1 sump tank components and materials should be corrosion-resistant metal material according to the characteristics of its interior materials.

5.1.2 The tank should be set aside. Spare tank sump same design requirements, and should use the maximum volume of the same groove.

5.1.3 The tank should meet the structural strength and seismic requirements, with sufficient corrosion allowance.

5.1.4 should be located within the sump cooling device, and meet one hundred percent reserve.

5.1.5 should be diluted and discharged radiolysis hydrogen tank within the tank to maintain negative pressure state, the air tank volume of hydrogen concentrations below 4.1%.

5.1.6 shall be provided within the tank stirring device, stirring manner and intensity should be avoided solid bottom sediment compaction.

5.1.7 shall be provided with reliable sampling device, sampling should be at different depths, to ensure getting a representative sample.

5.1.8 Sample storage tank should be set within a certain number of coupons, in order to meet the requirements of multiple sampling, including the base metal and weld samples, as in-service inspection One of the measures.

7.1 Safety Analysis

7.1.1 Design of response may lead to abnormal release of radioactive material anticipated operational occurrences, design basis accidents and serious safety analysis.

7.1.2 for a variety of events and incidents as defined in 7.1.1, should take the necessary precautions in the design, including detailed instructions to run people Countermeasures members should be taken to prevent the release of radioactive material exceeds the acceptable limit.

7.1.3 should be prepared safety analysis report, the format and content of the safety analysis report should be implemented in accordance with the relevant provisions of EJ/T 681's.

7.2 Environmental Impact Assessment

7.2.1 shall analyze and evaluate the impact of normal operation on the environment.

7.2.2 shall analyze and evaluate the impact of the incident on the environment conditions.

7.2.3 propose environmental protection measures should be taken.

8 radiation safety and monitoring measures

8.1.1 Control Principle dose

8.1.1.1 Radiation protection should be designed to comply with the relevant provisions of GB 18871 and the EJ849.

8.1.1.2 taking into account the economic and social factors in the future, individual radiation dose, and the possibility that the number of photos are kept reasonably achievable As far as possible low. Control principles and calculation of effective dose should implement the relevant provisions of GB 18871.

8.1.2 Radiation shielding design

8.1.2.1 Storage plant radiation shield shall be designed to ensure that the Radiation Workers annual effective doses lower than approved by the regulatory authorities of the Dose constraint value.

8.1.2.2 design should determine the maximum variation range of the storage building of the received high-level radioactive waste radioactivity should be calculated when the shield Leeway.

8.1.2.3 shield can not leave through-holes and crevices, where a duct, pipes, cables, etc. through the shield, steps should be taken to ensure that no Significantly weaken the shielding effect of the shield. It can be used in the form of penetrations.

8.1.2.4 In response to the binding site shielding material cut through radiation shielding necessary compensation.

8.2 Radiation Monitoring

8.2.1 shall be provided a fixed gamma monitor installed in a place where staff may stay or gamma-ray dose rate may be abnormal changes Home, for remote monitoring, exceeds a predetermined limit, the automatic alarm signal. Not set fixed monitoring point locations should be used portable (can Portable) dose meter monitoring.

8.2.2 shall be provided a fixed aerosol air sampling system in the plant, sampled periodically monitored. Not set a fixed place of sampling points, using mobile Aerosol sampler sampling monitoring.

8.2.3 should be set radioactive aerosol monitor, tank equipment for indoor air monitoring to analyze and judge the storage tank leaks.

8.2.4 Staff should be set monitoring tools inside and outside the irradiation dose.

8.2.5 response when the plant floor, walls, equipment, regular monitoring of surface contamination exceeds the limits specified in the national standard, should be promptly Decontamination.

8.2.6 cooling water storage tank should be monitored by radioactivity after passing the order to be discharged into the environment.

8.2.7 In the area around the storage tank should be based on the flow of groundwater and hydrogeological situation, reasonably well disposed to detect, so regular monitoring of well water The concentration of radioactive nuclides and components. Emergency 9 consider Take emergency measures in case of accidents should be considered when designing the required conditions, such as venues, roads, vehicles, facilities, equipment, communications liaison condition. 10 retired to consider

10.1 at the design stage should meet the requirements of the future decommissioning of the plant.

10.2 radiological equipment, piping and equipment room cladding, etc. should be easy decontamination, equipment room stainless steel cladding require smooth and clean, reduce cladding ride Connected components, reducing flushing less than the dead, unobstructed fluid can be discharged in order to provide convenient conditions for decommissioning. Stainless steel cladding is not installed and We need chemical decontamination of concrete floors or walls should be covered with easy decontamination materials to minimize contamination of the concrete. It should be easy to install Necessary temporary decontamination wash pipe. Site and plant layout space

10.3 should provide the necessary decommissioning, plant arrangement should be easy to build a gas account, temporary shielding and mobile ventilation means Makes it possible that equipment, pipes, valves demolition, hanging out and transport, as well as to prevent persons, objects cross-contamination.

10.4 structural design should consider the additional load when decommissioning or after retirement.