A Review on Flow Measurement in Sodium Cooled Fast Reactor Circuits

The Alkali metal sodium in liquid state is used as the coolant in sodium cooled fast reactors because of its good nuclear properties and admirable heat transfer properties. The economic, safe and sustained operation of sodium cooled fast breeder reactors depends on reliable and dependable monitoring of process parameters such as flow, accurately in its primary, secondary and auxiliary liquid sodium circuits. Like other sensors for sodium systems the relatively good electrical conductivity of liquid sodium is successfully used for flow measurement in pipelines. Different types of electromagnetic flow meters with different configurations are designed, constructed and were successfully in use internationally. The challenges and issues faced in pipe line sodium flow measurement using electromagnetic flow meters were addressed by researchers in India and abroad. China, Russia, Japan, Korea and France have very active fast reactor programme now. SFRs are currently in operation in India, Russia and China. In India Fast Breeder Test Reactor (FBTR) is in operation and Proto Type Fast Breeder Reactor (PFBR) is being commissioned at Kalpakkam, Tamil Nadu. The size of various pipes in sodium circuits of a typical 500 MWe SFR ranges from 15 nominal bore (NB) to 800 NB. Numerical modelling and analysis of Alnico-V based flow meters, sodium calibration of the flow meters to assess the deviation from numerical prediction, stability studies on Alnico-V based flow meters, design, analysis and manufacturing of flow meter with Samarium Cobalt magnets, development of side wall type flow meters, design and development of bypass type flow meters and application of ultrasonic flow meters for sodium flow measurement are the major developments in the area of sodium flow measurement in the recent past. This paper gives a comprehensive review on the recent developments in this domain and the recommendations made for the most suited flow meter for different sizes of pipes in future SFR circuits.