This paper describes the ongoing activities for the development of structural codes in Japan Society of Mechanical Engineers (JSME) for fast reactors including the Japanese prototype reactor Monju, and the demonstration reactor JSFR (Japan Sodium-cooled Fast Reactor), which is under conceptual design study. The existing design and construction code and welding code will be upgraded to support the design and construction of JSFR which involves various new features, among which are 60-year design and the application of new materials. Moreover, a fitness-for-service code, leak-beforebreak evaluation code and guidelines for structural reliability evaluation of passive components will be newly developed to be applied to the operation and maintenance of Monju and JSFR. Major revisions to incorporate the development are planned 2016 and 2020. Also discussed is an international perspective of codes and standards development and where the JSME Fast Reactor Codes stand in it.
