| Abstract [eng] |
Nuclear reactors fuel claddings and fuel channels are made of zirconium alloys, which, in addition to the ageing mechanisms of other metals, are also susceptive to hydrogen absorption and it following delayed hydride cracking mechanisms. Usually, the effects of the ageing of materials are evaluated by laboratory tests. As fuel claddings and fuel channels are the protective measures to prevent the release of radioactive fission products into the environment, their experimental studies are complex, difficult, and costly. Therefore, alternative methods are needed for the material ageing assessment. The aim of this research is to determine the fracture toughness of nuclear energy objects construction elements made of zirconium alloy with hydrides under thermal impact using the developed numerical method. To achieve the aim of the research a new numerical simulation methodology has been proposed, which allows numerical determination of fracture toughness of zirconium alloys at different hydrogen concentrations. Also, the crack growth determination methods were supplemented with the proposed and validated polynomial equation. By applying this methodology for the fuel channels and fuel claddings it is possible to predict a change in their properties due to the hydrogen absorption mechanism during the operation of a reactor or the storage of spent nuclear fuel. Therefore, using this methodology, it is possible to improve the design of fuel claddings and spent fuel storage procedures. |
