A detecting method for spherical fuel elements in pebble-bed HTGR using eddy current detection

• A detecting method for spherical fuel elements in pebble-bed HTGR is proposed.
• A signal identification algorithm was designed for fuel ball detection.
• Electromagnetic simulations were performed for analysis and optimization.
• Experiments were carried out for completion and verification of the method.

In pebble-bed high temperature gas-cooled reactors (HTGRs), spherical fuel elements move inside pipelines of a handling system, which should be controlled precisely. A detecting method for these elements is proposed in this paper, which is achieved by a detecting system with self-diagnosis function. Detecting signals are obtained by sensors installed outside pipes. A signal identification algorithm was designed for graphite ball detection. Electromagnetic simulations and detecting experiments were performed for system optimization and development of the method. The results show that the proposed method is capable for spherical fuel elements detection, and can be successfully used in practical application.