Measurement of reactor core temperature using multispectral infrared pyrometry in accidental conditions

摘要

The Loss Of Coolant Accident (LOCA) is one ofthe most considered accidental scenario innuclear power plant design [1]. It occurs after a breakof the primary circuit, which leads to a strongpressure decrease inducing an overheating of the fullcladding. The oxidation due to water steam and hightemperature undermines the claddings and can leadto their burst with the release of fission products [2].To simulate such accident, the Light-water One RodEquipment for LOCA Experimental Investigations(LORELEI) test device will be implemented in theJules Horowitz research reactor at the CEACadarache centre [3]. It will allow the study of fullcladdings behaviours under such conditions [4]. Thecladding surface temperature monitoring is essentialin this experiment; it allows linking the burstconditions with the temperature. However, thismeasurement needs to be non-invasive in order tominimize the perturbation and avoiding any changeof the burst conditions, which exclude the use ofthermocouples. In this case, the Pyrometry basedtemperature measurement techniques presents asuitable solution [5].