Model-based estimation and filtering for condition monitoring of AGR nuclear graphite cores

The graphite core is the critical component which dictates the life-time of an AGR (Advanced Gas-cooled Reactor) in a nuclear power station. To ensure the continued safe operation of an AGR nuclear plant, it is vital to closely monitor the condition of its graphite core to maintain its integrity for the economic life of the reactor. This paper presents a novel analytical approach for model-based condition monitoring of the AGR nuclear graphite core. By using a new first principles model for the refueling process, the friction forces can be estimated. In addition the aerodynamic-related forces for the whole core region can be separated from the masked FGLT (fuel grab load trace) data gathered during the charge and discharge refueling stages. The estimated friction and aerodynamic forces can be filtered further to remove any potential noise by using a three stage filtering procedure. As a result, the filtered FGLT data can be obtained by reconstructing the filtered friction and aerodynamic forces. To demonstrate the effectiveness the proposed analytical approach, an actual case from an AGR power plant is studied.