Rod Ejection Accident Simulation of a Small Pressurized Water Reactor

Abstract

Rod Ejection Accident (REA) is one of the major accidents which may result in the serious consequences during nuclear reactor operation. The study on REA is helpful to understand the physical characteristics and to verify the safety design of the core. The small pressurized water reactor (SPWR) adopts a relatively small amount of control rods. Therefore, when REA occurs, the positive reactivity introduced by the accident may be larger, resulting in more serious consequences. The integral design of SPWR results in different responses to the REA. Thus, it is necessary to investigate the REA of SPWR. In this paper, 3KeyMaster simulation platform, which is coupled with a thermo-hydraulic model and a three-dimensional space-time neutron dynamics model, is used to establish the reactor core model. Four single-beam control rods are selected to carry out REA, respectively. Simulations are performed, and results are collected. The responses of the SPWR are analyzed and accident procedures are obtained. Through analysis, it can be concluded that the serious consequences are caused when the R rod closest to the core, resulting in the maximum nuclear power peak. But the fuel center temperature and cladding temperature do not exceed the limit value, which proves the safety of SPWR and the rationality of core design.