Abstract
In this study, a reactor system thermohydraulic system analysis code, RELAP5/MOD3 is used to analyzed selected transients in the Final safety analysis report (FSAR) of Lungmen Nuclear Power Stations (NPS).The plant employs two general electric designed Advanced Boiling Water Reactor (ABWR) with rated power of 1350MWe. The Lungmen input deck of RELAP5/MOD3, models reactor pressure vessel (RPV) and banlance of plant (BOP), which includes major components such as turbines, heat ecxhangers, reheaters, and pumps. The input deck has been successfully initialize to a steady state condition. The internal pump trip and main steam line isolation valves closures transients in FSAR of Lungmen NPS are simulated. The results are compared with the data in FSAR. The comparsion of the simulated results with the results shown in FSAR are not satisfactory due to lack of modeling of the control system in the input deck.