Design and performance evaluation of Core Flow Monitoring Mechanisms for PFBR

The flow measuring system employs Core Flow Monitoring Mechanism (CFMM) equipped with Eddy Current Flow Sensor (ECFS) for sodium flow measurement. The system needs two CFMMs, one for fuel sub-assemblies and another for blanket and storage sub-assemblies. The necessary experimental studies were carried out for generating data needed for sodium flow estimation and to resolve uncertainties in the design of CFMM. Experimental studies include hydraulic studies and sodium calibration of ECFS. Subsequently, integrated assembly testing of CFMM was carried out to demonstrate the safe operation of the mechanisms before clearing for erection on pile. After successful completion of all the tests, both the CFMM were erected on pile. This paper discusses the detailed design features of CFMM and the developmental activities carried out to qualify the mechanism for reactor use.