Data fusion for enhanced condition monitoring of nuclear reactor refuelling

Existing Condition Monitoring (CM) at the UK’s fleet of Advanced Gas Cooled Reactors includes analysis of refueling, in order to derive information about the structural integrity of the core. This regular analysis is used to complement relatively infrequent core inspections, which occur every two to three years. The analysis itself depends on an inference of core damage from variation in friction during refueling, however the individual frictional components are not accurately known.
This paper presents a method of fusing available high‐resolution inspection data with lower resolution refueling data in order to estimate the individual frictional components. An algorithm is described which generates a characteristic equation for a given core channel, and allows the estimation of the frictional components. Comparing these frictional components to the refueling data allows the partial reconstruction of a channel geometry analogous to, but less detailed than, the inspection data. Case studies are presented for refueling when the reactor is off‐load, which simplifies the model of refueling, as coolant gas flows are at a
minimum. Further refinement of this technique may allow for increased understanding of the forces acting during the refueling process, such as coolant gas flows, which can vary based on refueling conditions.