Thermal mechanical analyser mode

For the overpower type transients, the Umiting failure mode is expected to be burst or pellet cladding mechanical interaction (PCMI). The maximum allowable powers listed in Table 2.8.1 are determined through the fuel rod thermal and mechanical analyses in Chap. 2, taking several conservatisms so as to prevent melting of the pellet centerline and keep the circumferential strain on the cladding... 

According to the formula of CaFesO compound, the Fe species presents both +2 and +3 oxidation state and a charge ordering (CO) mechanism is expected like previously reported in ref [4]. The [hOl] zone axes that exhibit extra dots have been also studied. However, these extra dots (blue arrows in Fig.3a) are not stable under electron beam the superstracture previously observed on ED pattern disappears when the microscope is switched into image mode. Such a nanostructural behaviour reinforces the hypothesis of a CO between the iron species. Thermal dependence and neutron diffraction data analyses are in progress to valid such a scenario. 

Dynamic mechanical thermal analyses were carried out using a Polymer Laboratories DMTA equipped with a high temperature (500°C) head operating at a frequency of 1 Hz and a constant strain, x 1, in the single cantilever mode. The thickness of the PES/PI2080 films was in the range of 0.1-0.2 mm and that of the PES/PI XU 218 films was 0.2-0.3 mm. 

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