Show simple item record

dc.contributor.authorPopel, Aleksej
dc.date.accessioned2017-06-29T15:48:15Z
dc.date.available2017-06-29T15:48:15Z
dc.date.issued2017-04-29
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/265103
dc.description.abstractThe aim of this work was to study the separate effect of fission fragment damage on the structural integrity and matrix dissolution of uranium dioxide in water. Radiation damage similar to fission damage was created by irradiating bulk undoped and doped ‘SIMFUEL’ disks of UO2, undoped bulk CeO2 and thin films of UO2 and CeO2 with high energy Xe and U ions. The UO2 thin films, with thicknesses in the range of 90 – 150 nm, were deposited onto (001), (110) and (111) orientations of single crystal LSAT (Al10La3O51Sr14Ta7) and YSZ (Yttria-Stabilised Zirconia) substrates. The CeO2 thin films were deposited onto single crystal silicon (001) substrates. Part of the bulk UO2 and CeO2 samples, the thin films of UO2 on the LSAT substrates and the thin films of CeO2 were irradiated with 92 MeV 129Xe23+ ions to a fluence of 4.8 × 1015 ions/cm2 to simulate the damage produced by fission fragments in uranium dioxide nuclear fuel. Part of the bulk UO2 and CeO2 samples and the thin films of UO2 on the YSZ substrates were irradiated with 110 MeV 238U31+ ions to a fluence of 5 × 1010, 5 × 1011 and 5 × 1012 ions/cm2 to study the accumulation of the damage induced. The irradiated and unirradiated samples were studied using scanning electron microscopy (SEM), focused ion beam (FIB), atomic force microscopy (AFM), energy dispersive X-ray (EDX) spectroscopy, electron probe microanalysis (EPMA), X-ray diffraction (XRD), electron backscatter diffraction (EBSD), secondary ion mass spectrometry (SIMS) and X-ray photoelectron spectroscopy (XPS) techniques to characterise the as-produced samples and assess the effects of the ion irradiations. Dissolution experiments were conducted to assess the effect of the Xe ion irradiation on the dissolution of the thin film UO2 samples on the LSAT substrates and the bulk and thin film CeO2 samples. The solutions obtained from the leaching of the irradiated and unirradiated samples were analysed using inductively coupled plasma mass spectrometry (ICP-MS). XRD studies of the bulk UO2 samples showed that the ion irradiations resulted in an increased lattice parameter, microstrain and decreased crystallite size, as expected. The irradiated UO2 thin films on the LSAT substrates underwent significant microstructural and crystallographic rearrangements. It was shown that by irradiating thin films of UO2 with high energy, high fluence ions, it is possible to produce a structure that is similar to a thin slice through the high burn-up structure. It is expected that the ion irradiation induced chemical mixing of the UO2 films with the substrate elements (La, Sr, Al, Ta). As a result, a material similar to a doped SIMFUEL with induced radiation damage was produced.en
dc.description.sponsorshipUK EPSRC (grant EP/I036400/1) and Radioactive Waste Management Ltd (formerly the Radioactive Waste Management Directorate of the UK Nuclear Decommissioning Authority, contract NPO004411A-EPS02)
dc.language.isoenen
dc.rightsAll Rights Reserveden
dc.rights.urihttps://www.rioxx.net/licenses/all-rights-reserved/en
dc.subjectUO2en
dc.subjectradiation damageen
dc.subjection irradiationen
dc.subjectthin filmen
dc.subjectCeO2en
dc.subjectXRDen
dc.subjectXPSen
dc.subjectICP-MSen
dc.subjectdissolutionen
dc.subjectsecondary phaseen
dc.subjectSEMen
dc.subjectAFMen
dc.subjectdissolution-precipitationen
dc.subjectspent nuclear fuelen
dc.subjectgeological disposalen
dc.subjectanoxic dissolutionen
dc.subjectSIMFUELen
dc.subjection-beam-induced mixingen
dc.subjectmicrostructureen
dc.subjectsingle crystalen
dc.subjectEBSDen
dc.subjectNano-structureen
dc.subjectKernel average misorientationen
dc.subjectGISAXSen
dc.subjectGIXRDen
dc.subjectEPMAen
dc.subjectSIMSen
dc.subjectFIB-SEMen
dc.subjectHS-AFMen
dc.subjectEDXen
dc.subjectGANILen
dc.subjectfission fragmenten
dc.subjectstructural stabilityen
dc.subjectnuclear fuelen
dc.titleThe effect of radiation damage by fission fragments on the structural stability and dissolution of the UO2 fuel matrixen
dc.typeThesisen
dc.type.qualificationlevelDoctoral
dc.type.qualificationnameDoctor of Philosophy (PhD)
dc.publisher.institutionUniversity of Cambridgeen
dc.publisher.departmentDepartment of Earth Sciencesen
dc.date.updated2017-06-29T15:36:15Z
dc.identifier.doi10.17863/CAM.11015
dc.contributor.orcidPopel, Aleksej [0000-0003-4436-9961]en
dc.publisher.collegePembroke College
dc.type.qualificationtitlePhD in Earth Sciences
cam.supervisorFarnan, Ian


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record