The graphic model of the spent fuel rod extracting system

The spent fuel rod extracting system is being developed in KAERI to deal with problems associated with utilization of storage pools at nuclear power plants. This system consists of an equipment system for extracting rods from spent fuel assemblies, a machine controller, and a supervisory controller. The performance of extraction system has been investigated through a series of experiments. Even though the system is designed to automatically perform sequential procedures, several problems have been found such as the gripper stucking to fuel rod caused by misaligned positioning and the socket jamming of impact wrench into the nut, etc. Up to this end the graphical model of the rod extracting system has been made so that possible sequences of operations including error detection and recovery actions are verified by using a graphic simulation before real operations. For the implementation, IGRIP is being used as a multifunctional tool for developing the rod extraction system. IGRIP is not only an excellent visualization tool, but it also highlights modeling virtual machine. (author). 6 refs., 1 tab., 6 figs