[en] This report provides an overview of research and development activities in Center for Computational Science and e-Systems (CCSE), JAEA, during the fiscal years 2007 and 2008 (Apr 1, 2007 - March 31, 2009). These research and development activities have been performed by the Simulation Technology R and D Office and Computer Science R and D Office. These activities include development of secure computational infrastructure for atomic energy research based on the grid technology, large scale seismic analysis of an entire nuclear reactor structure, large scale fluid dynamics simulation of J-PARC mercury target, large scale plasma simulation for nuclear fusion reactor, large scale atomic and subatomic simulations of nuclear fuels and materials for safety assessment, large scale quantum simulations of superconductor for the design of new devices and fundamental understanding of superconductivity, development of protein database for the identification of radiation-resistance gene, and large scale atomic simulation of proteins. (author)