R&D activities on oxygen sensor and potential control for lead-bismuth eutectic

Sugawara, Takanori  ; Yamaguchi, Kazushi; Obayashi, Hironari  ; Saito, Shigeru   ; Yoshimoto, Hidemitsu; Sasa, Toshinobu   

JAEA is planning to build a Transmutation Experimental Facility (TEF) for R&D on volume reduction and mitigation of harmfulness of high-level radioactive waste by using an Accelerator-Driven System (ADS). In the ADS Target Test Facility (TEF-T) of the TEF, a liquid lead-bismuth eutectic (LBE) target will be irradiated with a high-power (250 kW) proton beam, and irradiation effects on structural materials will be studied. On the other hand, LBE is corrosive, so it is necessary to control oxygen concentration in LBE adequately to protect structural materials from the corrosion. In order to control the oxygen concentration in LBE, it is required to develop an oxygen sensor to measure the oxygen concentration. JAEA tried to fabricate two-types of oxygen sensors (platinum type and bismuth type). As the result, it was confirmed that output voltage of the platinum type sensors was adequate in a wide temperature range.