Applicability of the system based code concept to the life-cycle design optimization of nuclear components

The System Based Code concept intends to optimize margins for nuclear plant component throughout the service period, by offering methodologies to determine appropriate margins corresponding to every technical field such as material, design, fabrication, installation, examination, operation, inservice inspections, repair and replacement, so that a total margin of the component is at a desired level. The authors have shown that this concept can successfully be applied to the design of relatively simple components of nozzles and end-caps. This paper explores the possibility of applying the concept of the System Based Code to more complex components whose design is directly connected to the design of the plant as a whole. As such example, a vessel equivalent to that of a regenerative heat exchanger of light water reactors was postulated. It was concluded that the concept could contribute to optimize the design of actual complicated components to the regions beyond the current codes and standards allow. Issues that are to be addressed in the further development are also described. (author)