Paul Gruber's research could contribute to the development of more durable fuel cladding for future nuclear reactors.
22 June 2026
One step closer to next-generation nuclear power
Researchers at Luleå University of Technology have developed a new method for manufacturing fuel cladding with improved corrosion resistance and accident tolerance. The results could contribute to safer nuclear power and are of particular interest for Generation IV reactors.
Lead-cooled fast reactors (LFRs) are often highlighted as a promising technology for the future of nuclear energy. However, their deployment depends on materials that can withstand high temperatures, corrosion and radiation over long periods of time.
In his doctoral thesis, Paul Gruber, Doctoral Student in Engineering Materials at Luleå University of Technology, developed a method in which a thin corrosion-resistant layer is applied to fuel cladding tubes using a laser-based processing technology. The result is nuclear fuel that will withstand the extreme conditions found in lead-cooled reactors for a prolonged duration.
“Lead-cooled fast reactors have the potential to contribute to both secure energy supply and reduced radiotoxicity of nuclear waste. At the same time, one of the greatest challenges is that the materials inside the reactor core must withstand corrosion, high temperatures and severe radiation damage over long periods of time. Our processing technology, called laser micro-wire cladding, makes it possible to manufacture composite fuel cladding that can withstand such environments,” says Paul Gruber.
Paul Gruber, doctoral student in engineering materials at Luleå University of Technology.
Combining Strength and Corrosion Resistance
The method is based on combining two different materials within the same fuel cladding tube. One material provides mechanical strength, while the other protects against corrosion from liquid lead.
Until now, it has been difficult to combine these properties in a single material. Laser micro-wire cladding deposits a coating with a strong metallurgical bond while preserving the properties of the underlying material.
“What makes the technology particularly interesting is that we can combine already certified materials with new, specifically developed steels for the harsh liquid lead environments,” says Paul Gruber.
Could Be Used Within a Few Years
The research focused on fuel cladding for lead-cooled Generation IV fast reactors, but the technology could also be applied to other components exposed to demanding operating environments.
The technology has already attracted interest from industry. The Swedish nuclear technology company Blykalla is exploring the possibility of using laser micro-wire cladding for future reactors.
“The technology is still under development and is being validated at the moment, and we are already seeing strong interest from industry. If development continues as planned, the method could be used in a Swedish research reactor within a few years,” says Paul Gruber.
Contact
Paul Gruber
- Researcher
- 0920-493251
- paul.gruber@ltu.se
- Paul Gruber
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