Abstract
This study consists of two objectives. The first objective is the implementation and assessments of the Moody HEM model of RELAP5-3D code. The second objective is the applicability and assessments for RELAP5-3D light water reactor containment model.According to the Standard Review Plan (NUREG-0800) of U.S. Nuclear Regulatory Commission, the homogeneous and thermal equilibrium critical flow model is acceptable for the containment sub-compartment pressure and temperature analysis. However, it was not built in the RELAP5-3D code. Therefore, the implementation and assessments of the Moody HEM model of RELAP5-3D code are performed in this study. After the implementation of the Moody HEM model of RELAP5-3D, three experiments of the Marviken Critical Flow Tests (CFTs) are selected as the assessment cases. The sensitivity studies and the comparisons with the RELAP5-3D built-in critical flow models are also included. The assessments of the Moody HEM model have good agreement with the test data. Also, the results of the sensitivity studies provide the model guidelines for the code users. Moreover, the results of the comparisons with the RELAP5-3D built-in critical flow models suggest that the newly implemented Moody HEM model may be slightly preferable than the other two built-in models. Thus, the first objective of this study is successfully achieved.As for the second objective, the versatility of RELAP5-3D code implies its applications are not only limited for LOCA analysis. The inception of this study is from one of the conference thesis of ICONE 17 that simulates the selected Marviken full scale containment test with the RELAP5 code. Three of the Swedish Marviken full scale containment tests are chosen for the assessment cases for the RELAP5-3D code and advanced containment analysis GOTHIC code. The comparisons between the test data, RELAP5-3D and GOTHIC simulations show that the overall tendencies of the containment parameters are quite similar. The phenomena of the vents clearance and flooding are also simulated quite well. The comparisons of the containment parameters between the test and simulations can be considered to have moderate approximations in values. Thus, the capability of RELAP5-3D code for pressure-suppression type containment simulation is assessed and the applicable category of the code also extends. In conclusion, the second objective of this study is also achieved.The practical application of this study is the containment system model of the Lungmen engineering simulation platform. A RELAP5-3D containment model is built with the Lungmen nuclear power plant design data and it is integrated into the simulation platform after performing the containment system stand-alone tests. Then the simulation platform can simulate the response of the containment system under the accidents or transient events.