According to the physical properties of radioactive waste, it can be divided into airborne waste, liquid waste and solid waste; according to the high and low levels of radioactivity, it can be divided into exempted waste, low-level radioactive waste, medium-level radioactive waste and high-level radioactive waste. Among them, exempted waste has a very low level of radioactivity and does not need to be controlled by radiation safety supervision and management organizations. The treatment of radioactive waste is called the treatment of radioactive waste, which is a process implemented to make radioactive waste into a state suitable for discharge into the atmosphere, water or for final disposal.
Radioactive waste treatment of nuclear power plants, one is the source control, the second is the classification of treatment. The so-called source control is to maximize the control of radioactive waste generation. All equipment, pipelines, valves, instruments, etc. in nuclear power plants are required to be made of corrosion-resistant materials and well sealed to prevent leakage of radioactive coolant; there are special systems to maximize the collection, purification, treatment, and reuse of radioactive waste liquids and gases.
The so-called categorized treatment is the radioactive waste that has been generated by the nuclear power plant is treated in different ways according to different categories. Reactor process equipment discharged exhaust gas to be injected into the storage tank under pressure, two or three months after the radioactive gas to be fully decayed, and then discharged from the chimney through a high-efficiency particulate filter in a controlled manner; radioactive waste, such as iodine 131 and other hazards, before the discharge of the liquid solution absorbed, or adsorbed with solid materials.
The waste liquid discharged from the process system of the nuclear power plant is generally medium or low level radioactive waste liquid, which should be properly purified and treated, and discharged into the river or the ocean under the condition of conforming to the national regulations, with the help of sufficient mixing with the water, highly diluted and diffused to achieve the safe discharge.
The reduction of radioactive solid waste through compression and incineration is an important means of radioactive solid waste disposal. Compression is the radioactive solid waste into the barrel compaction, so that the volume of solid waste is significantly reduced, and for combustible solid waste, incineration can be done in the reduction of capacity at the same time to reduce the weight. For low- and medium-emitting wastes, airtight containers are generally used for packaging, and for high-emitting solid wastes, concrete secondary containers are needed outside of the airtight containers. Packaged solid waste, intermediate storage for varying periods of time, and then for final disposal.
Disposal of radioactive waste to maintain the isolation of radioactive waste from the biosphere, until the radioactive waste decay to the level of non-hazardous to mankind by the measures taken is called the disposal of radioactive waste. Radioactive waste gases and liquids are decontaminated and most of the radionuclides have been concentrated in the solid waste.
Low- and medium-discharge solid waste can generally be isolated for three hundred years to reach a safe level, so the international community generally accepts the near-surface disposal of low- and medium-discharge wastes, and the safety of the disposal is achieved through the selection of suitable plant sites, good engineering measures and perfect management system. The final disposal of long-lived high-level waste is of great concern to the world and is an extremely complex technical problem.
Today, it is recognized that a more realistic option is to place properly packaged high-level waste into stable geological formations in the deep earth or into sediments on the deep seabed.