Milestone for lead-cooled reactors
This week, Oskarshamn was the scene of an important step for nuclear power with the start of construction of an electrically heated prototype for a future nuclear reactor. The company Blykalla and KTH researcher Janne Wallenius, who is developing solutions for cooling reactors with lead instead of water, are among those behind the project. However, the prototype will neither produce electricity nor be loaded with nuclear fuel.
So, Janne, what exactly will you be testing in Oskarshamn?
“One key focus is studying how lead can circulate naturally to cool the fuel rods under different accident scenarios. We’ll also be developing operational and maintenance processes, such as how to replace pumps and steam generators in molten lead at 350 degrees Celsius."
How does this prototype differ from the existing reactors in Oskarshamn?
"Blykalla’s small modular reactor (SMR) uses molten lead as a coolant, enabling passive safety in a highly compact design. Lead’s high boiling point, its ability to circulate naturally, and its built-in radiation shielding provide significant safety advantages."
What do you hope to achieve with the tests?
"We aim to validate the computational models used to design the reactor’s safety systems, which will support the licensing process for future construction and operation. Depending on the test results, we may need to adjust the design of these systems. The testing phase will run until the end of 2028."
What does this mean for KTH?
"This is a major milestone for KTH’s research and an important step in turning our knowledge into an industrial product with global potential."
Text: Anna Gullers