State-of-the-Art Report on the Piping and Instrumentation Design of RHRS in the Commercial NPPs

The objective of the study is for system designers to understand the technical state of the piping and instrumentation design of RHRS (or SCS) in the commercial nuclear power plants, thus to design more uncomplicated and advanced system. In this study, we have reviewed the design requirements and the technical state of piping and instrumentation design. Firstly we have reviewed the design requirements, including functional, isolation, pressure relief, pump protection, test requirements, etc.. Especially we have separately reviewed the design requirements of the low temperature overpressure, including ASME code requirements. Also we have reviewed the technical state of piping and instrumentation design, including piping design, PAMS design, ESFAS design, relief valve design, and instrument/valve/pump control design. In the piping design, the technical state of design has been investigated classified by the five regions, which have a little different design features, from the RCS suction line to the LPSI header line. Commonly, the P and ID is the design output which the related design requirements of the system have been all applied, also the operations for in-service inspection, heat-up/normal/cool-down, and emergency have been all considered. If we can understand well the design bases and its meanings of the P and ID, it would be helpful for us to design more uncomplicated and advanced system