[en] The assistance interface of calculation for innovative water reactor for flexible fuel cycle (FLWR) has been developed. The interface system should have an ability to display the output of core calculation code, graphically and simply. This Interface has an ability to access the result which is calculated by MOSRA code system as PDS files, and an ability to show the result graphically. The procedure to access the PDS files can be performed by using only mouse. Moreover, the distribution of the results, e.g, thermal power, can be shown as not only the axial graph but also the radial graph. Especially, for the radial graph, it can be shown as 3 dimensional graphics. These graphs can be saved as an image file, and the image file has the quality to use for report directly. Thus the outcome of developing the EVIRA code is beneficial for the research on FLWR. (author)