Pressure waves might be expected in a nuclear reactor system due to a sudden rupture of a pipe or to quick opening or closure of a system valve. Once generated, they can result in large mechanical loads on the reactor pressure vessel internal structures and pipelines, threatening their integrity. This kind of phenomenon is an important issue and a limiting accident case for nuclear power plant safety, which requires an extensive analysis to ensure plant safety. To study these phenomena, four pressure wave propagation (PWP) tests have been performed in the PMK-2 test facility in MTA-EK. In addition, the first one of the four tests has been used to assess the capability of the MARS-KS code in simulating PWP phenomena. Then, an input model representing the PMK-2 test facility was developed to simulate the tests. Herein, the MARS-KS code simulation results are compared with the test results for the first PWP test. The comparison shows that the MARS-KS code can simulate the PWP frequencies and pressure wave peaks well. After this qualified assessment, the MARS-KS code is then deployed to conduct a sensitivity analysis on the effect of the break size, break opening times, initial coolant conditions, and existence of the pressurizer on the PWP phenomena. The sensitivity analysis on the break opening times shows that the pressure wave amplitude is relevant to the break opening times and that the shorter the break opening time is, the faster the pressure depressurizes. The sensitivity analysis on the effect of the break sizes shows that the larger the break size is, the higher the pressure peak is. And, there is little effect of initial coolant pressure and temperatures and isolation of the pressurizer.