Embrittlement of Spent Fuel Claddings – Fracture Mechanical Evaluation and Failure Criteria
- The BAM research project BRUZL (Fracture mechanical analysis of spent fuel claddings during long-term dry interim storage) evaluates results of quasi-static Ring Compression Tests (RCT). Due to its simple realisation, the RCT is an established method for characterising the mechanical behaviour of fuel cladding, where a small tube sample is subjected to a compressive load and the relation between load and displacement is obtained. During tests at room temperature, unirradiated ZIRLO® samples with a distinct extend of radial hydrides have shown high susceptibility to sudden, brittle failure at relatively small loads. Hydride morphology and radial hydride metrics have been an integral part of the characterisation of degradation mechanisms of cladding. A software tool for the analysation of metallographic micrographs was developed. The program allows the automated calculation of hydride lengths, detection of continuous hydride structures, their statistical evaluation and visualisation.The BAM research project BRUZL (Fracture mechanical analysis of spent fuel claddings during long-term dry interim storage) evaluates results of quasi-static Ring Compression Tests (RCT). Due to its simple realisation, the RCT is an established method for characterising the mechanical behaviour of fuel cladding, where a small tube sample is subjected to a compressive load and the relation between load and displacement is obtained. During tests at room temperature, unirradiated ZIRLO® samples with a distinct extend of radial hydrides have shown high susceptibility to sudden, brittle failure at relatively small loads. Hydride morphology and radial hydride metrics have been an integral part of the characterisation of degradation mechanisms of cladding. A software tool for the analysation of metallographic micrographs was developed. The program allows the automated calculation of hydride lengths, detection of continuous hydride structures, their statistical evaluation and visualisation. Numerical models have been established to reproduce experimental RCT results featuring an elastic-plastic material model, which was derived from inverse finite element analyses of as-received RCT samples. A cohesive zone model (CZM) is introduced to the model to reproduce load drops in the linear regime of the load vs. displacement curve. Using a traction-separation approach for the CZM, the cohesive parameters are fitted to match numerical and experimental results yielding the fracture mechanical material properties. Combining the three key aspects hydride morphology, fracture mechanics and RCT stress-state a failure criterion can be established as a result of the BRUZL project. The project is funded by the Federal Ministry for Economic Affairs and Energy (BMWi) under contract no. 1501561.…
Autor*innen: | Kai Simbruner |
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Koautor*innen: | Uwe Zencker, Holger Völzke |
Dokumenttyp: | Vortrag |
Veröffentlichungsform: | Präsentation |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2021 |
Organisationseinheit der BAM: | 3 Gefahrgutumschließungen; Energiespeicher |
3 Gefahrgutumschließungen; Energiespeicher / 3.4 Sicherheit von Lagerbehältern | |
DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Angewandte Physik |
Freie Schlagwörter: | Ageing Management; Cladding Embrittlement; Extended Storage; Ring Compression Test; Spent Nuclear Fuel |
Themenfelder/Aktivitätsfelder der BAM: | Energie |
Energie / Kerntechnische Entsorgung | |
Veranstaltung: | 5th GRS Workshop on Safety of Extended Dry Storage of Spent Nuclear Fuel |
Veranstaltungsort: | Online meeting |
Beginndatum der Veranstaltung: | 09.06.2021 |
Enddatum der Veranstaltung: | 10.06.2021 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 19.11.2021 |
Referierte Publikation: | Nein |
Eingeladener Vortrag: | Nein |