Liquid metals have gained various applications in nuclear systems. Lead-Bismuth Eutectic (LBE) is
foreseen as coolant and target for neutron generation in accelerator driven systems (ADS), whereas
pure lead will be used as coolant in Gen IV-type lead-cooled fast reactors (LFR). The advantage of
heavy liquid metal alloys is their high thermal conductivity and their relative safety in case of an accident.
A major problem in non-isothermal systems is the corrosion of their structural components, consisting
mainly of ferritic/martensitic and austenitic stainless steels, as the solubility depends strongly on
temperature.
The formation of oxide scales on structural components is considered as a viable measure in limiting
the corrosion rates. To maintain specific oxygen content in lead or LBE an oxygen control system
(OCS) is indispensable for a safe operation. This requires the continuous measurement of the oxygen
activity in the liquid metal by means of electrochemical sensors. It must be assured that no oxides of
the liquid metal itself are formed; otherwise the system can be blocked. Therefore, this paper is dealing
with the development of oxygen sensors for corrosion control of martensitic and austenitic steels in eutectic
lead-bismuth system at Forschungszentrum Karlsruhe (FZK).
Keywords: Oxygen sensor, oxygen control system, corrosion, heavy liquid metals, accelerator driven
system, lead-cooled fast reactor