Scientists of the Tomsk Polytechnic University (TPU) have found a solution to one of the acute problems of the most widespread type of nuclear reactors in the world. According to the authors, the coating they have developed for nuclear fuel cells will significantly increase their corrosion resistance and almost eliminate the risk of leaks. The results are published in Materials Letters.
The fuel element, or TVEL, is the main element of the core of a nuclear reactor, inside of which the fission of radioactive fuel nuclei takes place. In case of emergency overheating in the world's most widespread pressurized water reactors, a reaction occurs between water vapor and zirconium cladding of fuel rods, which, according to TPU scientists, may be fraught with fuel leakage.
structure of new materials
The fact is that as a result of such a vapor-zirconium reaction, explosive hydrogen is released, and the shells themselves rather quickly lose their properties and may lose their tightness. The scientists explained that it is possible to protect the shells from destruction by creating special coatings on their surface. drawing.
“We investigated a variety of ways to modify the surface structure of various zirconium materials used in fuel rods. The optimum effect is obtained by a silicon carbide coating applied by the method of selective laser sintering. Tests have shown that our coating increases the resistance to mechanical damage possible during operation, ”said Andrey Lider, Professor of the Department of Experimental Physics of TPU.
The benefits of silicon carbide, the scientists explained, are excellent resistance to high temperatures and corrosion. University specialists have determined the optimal modes of application of this material, allowing to achieve low porosity of the coating and its high-quality adhesion to the surface of zirconium alloys. … This method, according to the authors of the work, can also become an important element of the NPP safety system. In 2021, TPU entered the Priority-2030 program, one of the university's research initiatives is dedicated to the development of future energy technologies.