Development of architecture for the detection of core flow blockage in KALIMER

Flow blockage of subassembly in the Liquid Metal Reactor (LMR) can be occurred by fragments from failed fuel or foreign materials left in primary coolant system. Flow blockage of subassembly may cause failure of clad and eventually whole core accident with sodium boiling. Therefore, the development of Flow Blockage Monitoring System (FBMS) is required for the protection of core accidents by early detection of flow blockage. In this report, gas and materials from failed fuel, local and gross boiling phenomena and temperature change due to flow blockage are established as the detection sources for the KALIMER FBMS by the analysis of physical phenomena, and gas tag, delayed neutron detector, acoustic detector, thermocouple are selected for the detection means of each source. RMS, PSD, skewness, ALN are confirmed applicable to the detection methods for the temperature. For the detection of boiling phenomena using acoustic detector, RMS, PSD, twice squaring, pulse counting, pattern recognition are applicable to the detection skills. Additionally, false trip probability and detection failure probability are suggested for the decision criteria of detection methods. Finally, the architecture of FBMS are established through the extraction of functional and detection requirements and the classification of function with protection and monitoring. The proposed architecture can be utilized for the basic design structure of KALIMER FBMS