Abstract
The objectives of this thesis are to establish the TRACE/PARCS coupling model for the ATWS analysis of Lungmen ABWR MSIV closure transient, and to verify that the design of Lungmen ABWR and a multitude of equipment and procedures described in FSAR, Chapter 15E ATWS Performance Evaluation, do have ability to mitigate the ATWS transient.There are three parts in ATWS analysis: ARI, FMCRD initiation and SLCS injection. In ARI and FMCRD initiation case, the core power, compared with that in control rod failing case, decreases obviously after control rod run-in. That is, the TRACE/PARCS coupling model established in this thesis indeed have ability to analyze the ARI and FMCRD initiation transient. In SLCS injection case, PARCS can not calculate the reactivity of boron without having the state variable IC ( Impurity of Coolant ) in PMAXS file. Thus, we substitute PARCS for point kinetics model.According to the results in ATWS analysis of Lungmen ABWR MSIVs closure transient, the design of Lungmen ABWR and a multitude of equipment and procedures described in FSAR are verified to have ability to mitigate the ATWS transient. And it also shows the importance of control rod. Reactor power will decrease rapidly as control rod run-in. If the ARI and FMCRD run-in fail simultaneously, the peak reactor power would still be controlled by pressure, RVs, void fraction and RIP rotation speed. However, the reactor core shutdown will then rely on the SLCS injection after 300sec.