Abstract
The purpose of this study is to develop oxygen sensor which can measure the oxygen potential of the fuel in a nuclear reactor. The oxygen sensor with CaO stabilized zirconia solid electrolyte has been specially designed in order to prolong its life time. Electromotive force (EMF) of solid galvanic cell Ni/NiO |ZrO2-CaO|Fe/FeO was measured in both the outpile tests and the in-situ tests using Japan Material Testing Reactor (JMTR), and the characteristics of EMF was discussed.
In the out-pile test, it was found that the EMF was almost equal to the theoretical values at temperatures ranging from 700 to 1, 000°C, and the life span of the sensor was very long up to 980h at 800°C. In the in-situ test, it was found that the EMF showed almost the reliable values up to 300h (neutron fluence (E>1 MeV) 1.5×1023n/mm2), at temperatures from 700 to 900°C. The imprecision of the EMF was found to be within 6% of the theoretical values up to 1, 650h irradiation time (neutron fluence (E>1MeV) 8.O×1023n/m-2) at 800°C, The oxygen sensors were found to be applicable for the oxygen potential measurement of the fuels in a reactor.
