Pyrometry techniques for temperature monitoring in simulated LOCA (Jules Horowitz Reactor)

In many experiments carried out in Material Testing Reactors the temperature is a key parameter for understanding the behavior of nuclear materials. Its estimation, depending on the localization in the reactor, may not be easy. The Light-water One Rod Equipment for LOCA Experimental Investigations (LORELEI) test device which will be implemented on the Jules Horowitz Reactor (MTR) illustrates this difficulty. In this device the CEA will simulate a Loss Of Coolant Accident (LOCA) transient. The aim is essentially to analyze cladding materials behavior in such a hard environment where steam oxidation is enhanced by temperatures exceeding 800°C. The ability to gauge the fuel rod temperature without contact and with a precision of ±10°C and in real time (1Hz) would constitute a great advantage for understanding and modeling the phenomena. This paper aims at describing the different pyrometry techniques that are studied for such a sensor.