When is it time to shut down a nuclear power plant?
Experts, among them Prof. Horst-Michael Prasser, discussed the state of the nuclear power plant Beznau I at a public event on October 27, 2016 in Baden.
The main topic of the discussion was the aluminum oxide inclusions in the steel of the reactor ring of Beznau I, the oldest nuclear power plant in Switzerland. Beznau I has been disconnected from the grid since March 2015 due to these irregular inclusions.
Horst-Michael Prasser, Head of the Laboratory of Nuclear Energy Systems, confirmed that such inclusions can be the result of the reactor ring’s production process. During the forging process, aluminum is often added to lower the oxygen content of the steel. The aluminum oxides do not always evaporate in the lower part of the casting. The blacksmiths therefore cut out these parts of the ring when the hole is being punched for the next step of the forging process. "If you don’t succeed in cutting it all out, some leftover oxides remain in the ring."