[en] The objective of the present research is the review of some sodium boiling models for LMRs (Liquid Metal Reactors), which are currently available in Korea and could be a reference for development of Korean own model. Since public safety should be assured not only under design basis accidents, but also under beyond design basis accidents, the assessment for the consequences from HCDA (Hypothetical Core Disruptive Accident) must be made strictly. For this purpose, the boiling model which provides the initial conditions for the HCDA analysis, should be ensured first of all. In this regard, the review of the state-of-art on the relevant methodology developed is extremely important to provide an essential background for development of the own safety analysis methodology. The present analysis addresses the understanding of the physical bases of sodium boiling models installed in SAS2A, SASSYS-1, and FRAX codes, two of which were developed in USA and one in Europe, respectively. Specifically, analysis of the governing equations adopted in those codes has been the main concern for this study and some model verification results available have also been demonstrated in this report. All models are similar, but some differences have been found in application of the equations to the problem, such as numerical method or constitutive relations. SASSYS-1 has updated boiling model comparing with SAS2A and, thus, the models in the two codes have generally shown similar structure to each other. On the other hand, the model in FRAX exhibits a little difference. As a result, SASSYS-1 is considered to be the most favorable model among 3 models examined in the present analysis. (author)