[en] Evaluation of turbulence models is performed for a better prediction of thermal stratification in an upper plenum of a liquid metal reactor by applying them to the experiment conducted at JNC. The turbulence models tested in the present study are the two-layer model, the k-w model, the v2-f model and the low-Reynolds number differential stress-flux model. When the algebraic flux model or differential flux model are used for treating the turbulent heat flux, there exist little differences between turbulence models in predicting the temporal variation of temperature. However, the v2-f model and the low-Reynolds number differential stress-flux model better predict the steep gradient of temperature at the interface of thermal stratification, and only the v2-f model predicts properly the oscillation of temperature. The LES is needed for a better prediction of the amplitude and frequency of the temperature fluctuation

[en] Flow blockage of subassembly in the Korea Advanced Liquid Metal Reactor (KALIMER) can be occurred by fragments from failed fuel or foreign materials left in primary coolant system. Flow blockage of subassembly may cause failure of fuel and eventually core damage accident. Therefore, the development of Flow Blockage Detection System is required for the protection of core damage accidents by early detection of flow blockage. In this paper, 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 detection system by the analysis of physical phenomena, and gas tag, delayed neutron detector, acoustic detector, thermocouple are selected for the detection means of each source. After analysis of detection methodology based on temperature and acoustic, the preliminary architecture is established through the extraction of functional and detection requirements and the classification of function with protection and monitoring

[en] The DWTSG concept is proposed as a new liquid metal reactor concept to avoid sodium-water reaction incidents in the SG. This present paper attempts to assess thermal characteristics of DWTSG in the this alternate concepts. The concept provides double barrier between the sodium and the steam. This will result in improved reliability of SG compared to the conventional steam generator design using single wall tubes. The gap between the inner and outer tubes affects the heat transfer from sodium to steam. To estimate heat transfer performance of the concept, the required heat transfer area was calculated, and compared with MONJU SG. In the case of eliminating of IHTS the required heat transfer area for DWTSG is equally mated to that of MONJU design