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Kinga Suchorab

Publications and source records attributed to Kinga Suchorab.

3 recordsLinked to original sources

Preliminary Structural Study of Chromium Coatings for Nuclear Applications

Following the Fukushima Daiichi disaster, an increasing number of studies concentrate on the development of Accident Tolerant Fuel (ATF) cladding materials for nuclear fuel, aiming to prevent the oxidation of zirconium during incidents such as Loss of Coolant Accident (LOCA) and to effectively lower the amount of heat and hydrogen released during emergency core cooling (ECC). Zirconium alloy cladding with a protective chromium (Cr) coating is considered one of the promising candidates, largely due to its relatively short timeline for deployment in nuclear power plants. In this study, Cr-coated and uncoated Zircaloy-4 claddings were evaluated using high temperature X-ray diffraction (HT-XRD) in vacuum over a temperature range from RT to 1100oC. The temperatures corresponding to the formation of oxide phases are >200oC and >600oC for the uncoated and Cr-coated samples, respectively. SEM and TEM characterisation of the sub-surface in Cr-coated specimen after HT-XRD revealed Fe segregation, formation of Zr(Fe,Cr)2 Laves phase and nano-bubbles at the former Cr / Z4 interface.

cond-mat.mtrl-sci

Evolution of radiation-induced damage in nuclear graphite -- a comparative structural and microstructural study

Graphite, as a material for high-temperature gas-cooled reactors (HTGR), will be exposed to harsh environment. The stability of graphite structure under irradiation is of a key importance for efficiency, reliability and security of the Generation IV nuclear reactors. Three types of nuclear grade graphite were subjected to irradiation in this research - two commercially manufactured (IG-110 and NBG-17) and the laboratory's in-home material (NCBJ). The samples were exposed to 150 keV Ar+ and He+ ions bombardment at 400 C with fluences ranging from 1E12 to 2E17 ion/cm2 in order to simulate in-reactor conditions. For analysis of the level of structure damage, type of created defects and crystallite size changes under ion irradiation ex-situ Raman spectroscopy was used. The methodology of spectra fitting was developed. Furthermore, SEM observation of irradiated materials was performed. Results showed structural degradation of materials by the means of amorphisation: slight at a low fluence level, rising rapidly at higher irradiation values. Furthermore, stronger structural disorder was found in the materials irradiated with heavier Ar+ ions than with lighter He+. Microstructural evolution of the nuclear graphites aligned with the structural deterioration in its stepwise character.

cond-mat.mtrl-sci

Surface and in-depth structural changes in nuclear graphite irradiated with noble gases described with Raman imaging

4th Generation high-temperature gas-cooled nuclear reactors (HTGR) are regarded as possible sources of industrial heat in Poland and Europe, allowing for a substantial reduction of the dependency on gas and coal import. It is mainly due to their safety of use, reliability and economy in a current energetic crisis. In this work, graphite, as a primary construction material and neutron moderator in HTGR, was evaluated before and after ion irradiation since its properties depend on the material's structure and purity. Commercial graphite materials (IG-110, NBG-17) and the laboratory's in-home material were chosen for the exemplary samples. The structural damage in HTGR was simulated with energetic Ar+ and He+ ions with fluencies from 1E12 to 2E17 ion/cm2. Raman imaging was chosen to assess radiation damage build-up: the crystallites' evolution, occurrence and types of defects. The recorded evolution showed stronger disordering of the material with heavier Ar+ ions than with He+.

cond-mat.mtrl-sci