Coatings for nuclear fuel preventing explosions in reactors
Protective titanium nitride-based coatings will be a barrier protecting zirconium fuel rods
Tomsk Polytechnic University
"In reactors nuclear fuel is laid in special "tubes" out of zirconium alloys, to form fuel rods. In the fuel rods, a nuclear reaction takes place. As a result of radiolysis of a reactor coolant - water, and also as a result of interaction of the coolant and zirconium under high temperatures hydrogen is released. Hydrogen is able to accumulate in fuel rods shells causing degradation of their mechanical properties and destruction," clarifies one of the developers, an assistant at the Department of General Physics Egor Kashkarov.
According to the young scientist, the danger of interaction of zirconium and water is the higher temperature in the reactor is, the more hydrogen is released. For example, the same happened at the Fukusima-1 station in Japan: due to flooding of pumping equipment the active zone of the reactor warmed up to more than 1,200 °C, a steam-zirconium reaction proceeded swiftly and a large amount of hydrogen was released. The explosion of accumulated hydrogen was one of the biggest radiation accidents in the world.
The scientific team from the TPU Department of General Physics is creating protective titanium nitride-based coatings that will be a barrier protecting zirconium fuel rods from water and hydrogen accumulation.
"During tests titanium nitride has proved itself well: it has high hardness, wear resistance, heat resistance and inertia. We also found that it protects well from hydrogen penetration into the material, what is critical for nuclear energy. The coatings can reduce hydrogen penetration in zirconium alloy," adds Egor Kashkarov.
The coatings on zirconium substrate are applied using two technologies: magnetron sputtering and vacuum arc deposition. The both processes are carried out on a set-up created in the university. The result is a thin film coating - no more than two microns thick.
"One of the applications of the elaborating coatings out of titanium nitride is next generation reactors and thermal nuclear reactors where hydrogen impermeable coating is a pressing issue. In the next generation reactors, temperature is supposed to increase up to 400-450 °C to improve fuel burn-up efficiency. Consequently, hydrogenation of fuel rods will be here much faster. Our coatings are able to prevent it," says the developer.
Original publication
Other news from the department science
These products might interest you
Berghof Reaktortechnologie - Hoch- und Niederdruckreaktoren, Druckbehälter und metallfreie Reaktoren by Berghof
Safe high- and low-pressure systems for aggressive media
Corrosion-resistant reactors with PTFE lining - individually configurable
BUCHI MINICLAVE by C3 Prozess- und Analysentechnik
Flexible small reactor systems - acid resistance, visual control and individual customization options for a wide range of applications!
PhotoSyn™ by Uniqsis
Experience the future of photochemistry
Flow reactor with user-friendly control for higher yields and selectivity
Get the chemical industry in your inbox
From now on, don't miss a thing: Our newsletter for the chemical industry, analytics, lab technology and process engineering brings you up to date every Tuesday and Thursday. The latest industry news, product highlights and innovations - compact and easy to understand in your inbox. Researched by us so you don't have to.