Difference between nuclear waste water and nuclear sewage

The difference between nuclear wastewater and nuclear wastewater lies in the source, composition and treatment method.

I. Sources

1, nuclear sewage refers to water polluted by nuclear fuel, such as high-level radioactive waste water produced in nuclear accident or cooling water directly contacting with nuclear fuel. These waters usually contain a lot of radioactive elements, such as uranium, plutonium, cesium, strontium, iodine, cobalt and so on. It is highly radioactive and dangerous.

2. Nuclear waste water refers to water containing radioactive isotopes discharged from nuclear power plants, such as low-level waste water used for cleaning, dust removal, seawater desalination and other purposes, or waste water that still contains trace radioactive substances after treatment. These waters mainly contain tritium, a radioactive isotope of hydrogen, which is low in radioactivity and dangerous.

Second, composition

1. Nuclear sewage contains many radioactive elements, such as uranium, plutonium, cesium, strontium, iodine and cobalt. Some of them have a long half-life, for example, the half-life of uranium 238 is 4.5 billion years, and that of plutonium 239 is 24,000 years.

2. The nuclear waste water mainly contains tritium, a radioactive isotope of hydrogen, and its half-life is 12.3 years. Although tritium has low radioactivity, it can combine with oxygen to form tritium oxide (heavy water) because it is similar to ordinary hydrogen.

Third, the treatment method

1. Because the nuclear sewage is highly radioactive and dangerous, it needs to be treated by various methods to reduce its radioactive intensity and volume, and to solidify or stabilize it for safe storage or disposal. Commonly used treatment methods include chemical precipitation, ion exchange, adsorption, evaporation and concentration, membrane separation technology, biological treatment, magnetic molecular method, inert curing method and so on.

2. Because of its low radioactivity and low risk, nuclear wastewater can be treated by simple methods to meet the discharge standard or reuse standard. Commonly used treatment methods include precipitation, filtration and reverse osmosis. These methods can effectively remove tritium or other trace radioactive substances from nuclear waste water.

Treatment methods of nuclear wastewater:

1, chemical precipitation method

Chemical precipitation is a method of precipitation between precipitant and trace radionuclide in wastewater. This method takes advantage of the insolubility of radionuclides such as hydroxide, carbonate and phosphate. The purpose of chemical treatment is to make the radionuclides in wastewater migrate and gather in small sludge, so that there is almost no radioactive residue in the precipitated wastewater, thus reaching the discharge standard.

2. Ion exchange method

Many radionuclides are in ionic state in water, especially radioactive wastewater after chemical precipitation. Because of the removal of suspended and colloidal radionuclides, the rest are almost all ionic and most of them are cations. And radionuclides exist in trace amounts in water, which is very suitable for ion exchange treatment, and ion exchange can work effectively for a long time without the interference of non-radioactive ions.

Refer to the above content: Baidu Encyclopedia-Nuclear Wastewater

Baidu encyclopedia-radionuclide