Experimental Studies on Qualification of Structural Integrity of Eddy Current Flow Meter

An eddy current flow sensor (ECFS) is used for measuring the sodium flow through the reactor core in prototype fast breeder reactor (PFBR). Being a safety critical system, ensuring the structural integrity of the sensor and associated support systems has a direct bearing on the safety and the availability of the reactor. The sensor operates in a harsh environment with maximum sodium temperature up to 525 °C, subjected to thermal shocks, seismic-induced loading, and flow-induced vibrations. The sensor employs special materials, components (MgO coil) which are not covered by codes. Due to non-availability of design guidelines in design codes for these sensors, the structural integrity of this sensor was demonstrated experimentally. Codal guidelines were extended wherever possible to aid in the experimental program. All the experiments done, other than FIV, are presented in the paper. During these tests, in addition to integrity, other functional checks were also carried out. The tests demonstrated the structural integrity of the ECFM and provided basis for obtaining regulatory clearance for ECFM.