For a severe accident of nuclear power plant, an approach to estimation of the radiological source term using a severe accident code(MELCOR) has been proposed. Although the MELCOR code has a capability to estimate the radio-logical source term, it has been hardly utilized for the radiological consequence analysis mainly due to a lack of un-derstanding on the relevant function employed in MELCOR and severe accident phenomena. In order to estimate the severe accident source term to be linked with the radiological consequence analysis, this study proposes 4-step pro-cedure: (1) selection of plant condition leading to a severe accident(i.e, accident sequence), (2) analysis of the rele-vant severe accident code, (3)investigation of the code analysis results and post-processing, and (4) generation of radio-logical source term information for the consequence analysis. The feasibility study of the present approach to an early containment failure sequence caused by a fast station blackout(SBO) of a reference plant (OPR-1000), showed that while the MELCOR code has an integrated capability for severe accident and source term analysis, it has a large degree of uncertainty in quantifying the radiological source term. Key insights obtained from the present study were: (1) key parameters employed in a typical code for the consequence analysis(i.e., MACCS) could be generated by MELCOR code; (2) the MELOCR code simulation for an assessment of the selected accident; and (3) the generation of source term infor-mation for the consequence analysis relies on an expert opinion in both areas of severe accident analysis and conse- quence analysis. Nevertheless, the MELCOR code had a great advantage in estimating the radiological source term such as reflection of the current state of art in the area of severe accident and radiological source term.