Sodium Fast Reactors power monitoring using high resolution and high count rate gamma spectrometry. Simulation study

Sodium Fast Reactors (SFR) are studied in the international generation IV project to preserve uranium resources and transmute minor actinides. The french Phenix experimental reactor has already shown promising results. The reactor power is commonly calculated simultaneously by heat balance on water to vapour heat exchanger and by neutron flux measurements. Concentration of some gamma radionuclides in the primary coolant is also directly correlated with power. Therefore, we think that an on-line gamma measurement system could be settled as another help for generation IV SFR reactor exploitation. The ²⁰F is a particularly convenient tagging agent to design a fast time response system. This work shows that a gamma spectrometry system measuring the ²⁰F activity could be set as a power monitoring system for SFR reactor. This system will be tested at the Phenix reactor with the high count rate and high resolution Adonis spectrometer.