Characterisation of high temperature refractory ceramics for nuclear applications

Bottomley, D.; Wiss, Th; Janßen, Andreas; Cremer, B.; Thiele, H.; Manara, D.; Scheindlin, M; Murray-Farthing, Mairead; Lajarge, P.; Menna, M; Bouexière, D; Rondinella, V.V.

doi:10.1088/1757-899x/32/1/012003

Cited by 7 publications

(3 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Post-test examinations are done on cross-sections of the sample molten zone by OM and SEM-EDX to determine the composition of the molten material along with their melting and solidification points. This helps in establishing the limits of the phase domains [17][18][19].…”

Section: Jrc-itu-fast Laser Flash (Flf) Facilitymentioning

confidence: 99%

Investigations of the melting behaviour of the U–Zr–Fe–O system

Bottomley

Murray-Farthing

Manara

et al. 2015

Journal of Nuclear Science and Technology

View full text Add to dashboard Cite

During a severe nuclear accident, the UO 2 fuel rods, Zircaloy cladding, guide tubes, absorber and steel structural components inside the reactor pressure vessel overheat and a series of interactions between these elements and the steam atmosphere occur. These produce more heat in addition to the decay heat and result in a liquid corium of oxidic and metallic phases depending on the exact conditions and processes. A major systems resulting from this is the U-Zr-Fe-O system. High-temperature data for this system is important in order to be able to model these interactions. The Joint Research Centre, Institute for Transuranium Elements (JRC-ITU) has been examining the melting ranges for this system over the whole FeO range by means of a specialized laser flash technique that achieves very high temperatures and avoids crucible contamination. The melted zones were examined for their structure, composition and for estimation of the liquidus and solidus temperatures. The results showed that with FeO contents of over 20mol% there was a very large melting range that would permit long liquid cooling times and extend the relocation of fuel material within the reactor pressure vessel. Based on these results, the main phase regimes expected under severe accident conditions could be identified.

show abstract

Section: Jrc-itu-fast Laser Flash (Flf) Facilitymentioning

confidence: 99%

Investigations of the melting behaviour of the U–Zr–Fe–O system

Bottomley

Murray-Farthing

Manara

et al. 2015

Journal of Nuclear Science and Technology

View full text Add to dashboard Cite

show abstract

“…In the field of nuclear fission research, there are several works dealing with the use of high power laser / material interactions for the investigation of the properties of fuel materials at high temperature, starting from the 80's [4,5]. Particularly, laser heating devices together with analysis diagnostics and temperature monitoring systems have been applied for the measurement of thermal properties (heat capacity, diffusivity, conductivity) [6] and thermodynamic properties (melting point, evaporation point, vapor pressure, equation of state) [7][8][9][10][11][12][13][14][15]. Combined laser heating with sample levitation and synchrotron x-rays has also allowed studying molten uranium dioxide structure at very high temperature (up to 3270K) [16].…”

Section: A Laser Heating Approachmentioning

confidence: 99%

Using laser remote heating to simulate extreme thermal heat loads on nuclear fuels

et al. 2020

View full text Add to dashboard Cite

Up to now, predicting accurately the Fission Gas Release (FGR) from high burn up UO2 and/or MOX (Mixed Oxide) fuels at off-normal conditions, such as power transient, reactivity-initiated accident (RIA) and loss-of-coolant accident (LOCA), is still a significant and very challenging task. For this purpose, different R&D programs have been carried out in France, as well as in other countries. This has been done with a specific emphasis on mechanisms which promote the FGR under accidental conditions. These studies can be performed thanks to dedicated integral experiments conducted in-pile (i.e. in Materials Testing Reactor) with the corresponding cost and constraints, or at the laboratory scale with annealing tests which allow to be representative of specific parameters (thermal history for instance). During these annealing tests under well-known conditions (temperature, atmosphere), both the absolute level and the time dependence of the released gases should be monitored, together with the corresponding fuel micro-structural changes, since experimental knowledge of fission gas release alone is not efficient enough. This approach requires more and more accurate on-line measurements. This corresponds to the driving force of the present work. In this contribution, we will present our progress in developing an experimental platform that can submit nuclear fuel and cladding samples to annealing tests involving very high temperatures (up to 2500°C) and very fast temperature ramp (up to thousands of °C/s) with controlled thermal gradients and temporal dynamics. This new platform implements innovative instrumentation, such as optical diagnostics to measure fuel fragmentation kinetics and infrared pyrometry for temperature monitoring. This experiment is based on a high-power laser (1.5kW) coupled to an experimental chamber with controlled atmosphere (Ar, N2, or vacuum) and specific optical components. Based on the spatial beam profile and temporal power function of the laser, it is possible which such a system to produce complex spatio-temporal temperature gradients, relevant for addressing different research needs. It provides access to extreme conditions that are very difficult to reach with other means. Particularly, one of main objectives of this work is to investigate conditions of Reactivity Initiated Accident (RIA). The first experiments performed on inactive materials, non-irradiated uranium dioxide, is presented in order to highlight the capabilities of this technique.

show abstract

“…Investigations related to different types of concretes, mostly reinforced using various reinforcements, were focused on studying effects of lateral load, static tests, tension stiffening [8][9][10][11][12], while some papers dealt with the laser machining of structural ceramics [12]. Also, there are some papers referred to the ceramics (high temperature refractory ceramics) and their characterization for nuclear applications [13] and monitoring behavior when they are subjected to the excimer laser radiation [14].…”

Section: Introductionmentioning

confidence: 99%