Application of the System Based Code Concept to the ASME Code for Liquid Metal Reactors

The System Based Code (SBC) which was initially proposed by Asada forms the basis of the development of a set of codes and standards in Japan that fully take advantage of the potential of liquid metal reactors (LMRs). The concept of SBC is also being elaborated within the American Society of Mechanical Engineers (ASME) as a promising way that improves current codes and standards by allowing significantly wider technical options with various advantages both in Sections III and XI through bridging them. This paper illustrates an envisioned scheme for code rules for new reactors based on the SBC concept that could be also implemented in ASME Boiler and Pressure Vessel Codes. The outline of technologies needed to materialize the concept such as “Break Size Limitation Analysis (BSLA)” and structural reliability evaluation are also described. Recent discussions in ASME indicate that efforts on drafting code rules based on the SBC concept will soon take place in ASME.