Modelling of oxygen diffusion and consumption in an XLPE cableinsulation for nuclear power applications using an oxidationdependentdiffusion-reaction approach
(English)Manuscript (preprint) (Other academic)
The oxidation profile of an XLPE conductor insulation after accelerated ageing atdifferent temperature/dose-rate combinations was assessed through infrared spectroscopy, tostudy heterogeneous oxidation in the samples. These profiles showed clear drops in oxidationdegree towards the centre of the cable, to such an extent that more than half of the thicknesswas essentially not oxidized. The oxygen diffusion and consumption was then modelledthrough computer simulations to obtain the diffusion coefficient and reaction rate, includingtheir possible dependencies on the oxidation degree. The model was based on the assumptionthat diffusion and consumption rates, and solubility of oxygen in polyethylene weredependent on the degree of oxidation relative to a maximum degree of oxidation. Good fitswith experimental data were obtained, and the model could be applied to data from literaturewith promising results.
Polyethylene, Radiation ageing, Thermal ageing, Oxygen diffusion, Computer modelling, Lifetime prediction
Textile, Rubber and Polymeric Materials
IdentifiersURN: urn:nbn:se:kth:diva-168189OAI: oai:DiVA.org:kth-168189DiVA: diva2:814645
FunderEU, FP7, Seventh Framework Programme
QS 20152015-05-272015-05-272015-05-29Bibliographically approved