Pwr Control Rod Ejection Analysis with the Moc Code Decart

During the past several years, a comprehensive high fidelity reactor core modeling capability has been developed called the Numerical Nuclear Reactor (NNR) for detailed analysis of Light Water Reactors. The project was initially sponsored as part of a US-ROK collaborative DOE I-NERI project and the past two years has been sponsored by EPRI to address specific fuel performance issues as part of EPRI BWR Fuel Reliability Program. The NNR achieves high fidelity by integrating whole-core neutron transport solution and ultra-fine-mesh computational fluid dynamics/heat transfer solution. During the past several months there has been interest in taking advantage of the NNR to improve the fidelity for LWR transient analysis. The work described in this paper is a preliminary demonstration of the ability of the whole core neutron transport code, DeCART, to provide a accurate core average power during a control rod ejection. The current state of the art in analysis of this event is to rely upon the assembly averaged power from a whole core nodal neutronics to provide a conservative analysis.