Nuclear wastewater and nuclear sewage seem to be only one word apart, but the difference is big.
Nuclear wastewater, refers to:Treated water containing radioactive material, mainly used in the operation of nuclear power plants, including cooling water, equipment flushing water, gaseous discharge condensate, etc. In summary, it includes wastewater used to cool nuclear reactors and wastewater used to treat radioactive waste. It usually arises as a result of the operation of a nuclear facilityProduced by normal discharge or emergency treatment after a nuclear accident。There are several ways to treat nuclear wastewater, including:Dilution, precipitation, filtration, adsorption, ion exchange, evaporation, coagulationWait.
The generation of nuclear wastewater is inevitable, and at the same time, it is controllable and manageable.
The treated nuclear wastewater must comply with the International Atomic Energy Agency (IAEA) and relevant national standards before it can be discharged into the environment.
Nuclear sewagei.e. nuclear-contaminated water. , refers to:Water containing radioactive materialIt is usually caused by a nuclear accident, a nuclear test, the use of nuclear **, or the operation of a nuclear facility. Nuclear wastewater is uncontrollable and is usually caused by major accidents or natural disasters.
Nuclear sewage is extremely harmful to the environment and human health, because radioactive materials can enter organisms through the food chain, water cycle, airborne and other waysGenetic mutations, cancer, malformations, deathand other consequences.
The difference between nuclear-contaminated water and nuclear wastewater is mainly that it is treatedafter the ability to reach radioactive materialEmission standards
Nuclear-contaminated water is water containing radioactive materials that has not been treated or has not met the discharge standards.
Nuclear wastewater, on the other hand, is water containing radioactive materials that has been treated and meets the discharge standards.
1.There is a qualitative difference between the two, not just the difference in quantity. The radioactive isotope tritium, which contains mainly hydrogen, has a half-life of 123 years.
Nuclear sewage contains a variety of radioactive elements, such as uranium, plutonium, cesium, strontium, iodine, cobalt, etc., some of which have a long half-life, such as uranium-238 has a half-life of 4.5 billion years, and plutonium-239 has a half-life of 240,000 years.
Therefore, the radioactive elements brought by the nuclear sewage are very toxic and long-lasting.
2.Different treatment methods for nuclear wastewater and nuclear wastewater. For nuclear wastewater, evaporation, precipitation, filtration and other methods are usually used to remove radioactive materials. Due to its low radioactivity and low hazard, it can be treated in a simpler way to meet emission or reuse standards.
For nuclear wastewater, due to its high radioactivity and high risk, it needs to be treated by a variety of methods to reduce its radioactive intensity and volume, and solidify or stabilize it, according to its specific composition and concentration, for more complex and targeted treatmentfor safe storage or disposal.
Three. The hazards caused by the discharge of nuclear sewage from the Fukushima Daiichi nuclear power plant in Japan
On March 11, 2011, Japan had a 9The magnitude 0 tsunami caused a serious meltdown at the Fukushima Daiichi Nuclear Power Plant。It was the world's worst nuclear accident after the Chernobyl accident in the Soviet Union in 1986.
After the accident, in order to cool the reactor and fuel pool, it was necessary to inject large quantities of fresh water and seawater. These injected waters, when they come into contact with the reactor, become highly radioactively contaminated. In order to prevent this contaminated water from leaking into the outside environment, it is stored in large tanks on site. However, due to the need to inject new cooling water every day, the storage tank's capacity was already close to its limit.
On April 13, 2021, Japan** officially decided to store about 1.25 million tons of storage tanks at the Fukushima Daiichi Nuclear Power PlantHigh concentrationNuclear sewageDischarged into the Pacific Ocean. Japan** claims that the water has undergone multiple layers of treatment to remove all radioactive material except tritium and is therefore safe.
There are several problems with the statement of the Japanese **:
First of all,Japan** does not openly and transparently disclose the specific methods, effects and standards of water treatment, nor does it accept third-party supervision and testing。Therefore, there is no guarantee that the treated water will actually meet the requirements for safe discharge.
Second, Japan** did not adequately consider the hazards of tritium residues in treated water. Tritium is oneHeavy hydrogen, is one of the raw materials for the hydrogen bomb, has a strongBioaccumulationwithCarcinogenicity。Tritium can enter marine ecosystems through the water cycle, affect the growth and reproduction of marine organisms, and even pass on to humans through the food chain.
In addition, Japan** did not adequately assess the impact of the discharge of treated water on neighboring countries and regions. The Pacific Ocean is the largest ocean in the world, involving the interests and security of many countries and regions. The discharge of treated water will not only pollute the marine environment, but also damage economic fields such as fisheries, tourism, and marine resources, and even cause international disputes and conflicts.
Therefore, the Fukushima Daiichi nuclear power plant discharge incident in Japan has been opposed by people in many countries and regions, including the Japanese people, which is a serious environmental problem and a global challenge. The international community needs to work together to take effective measures to address and solve this problem and protect the global environment and human health.