Contribution to the description of the absorber rod behavior in severe accident conditions: An experimental investigation of the Ag–Zr phase diagram

An Updated Thermodynamic Modeling of the Al-Zr System

“…And the partial enthalpy of mixing of Zr in the Al(liquid) phase has been also measured using calorimetric techniques by Ansara et al [50] under purified argon for xZr < 1.4910 3, by Gomozov et al [51] at 1030 K, using an aluminium oxide crucible under vacuum for xZr < 1.01910 À5 , a DRX analysis after the experiment showed that Zr has been uniformly dissolved in the solvent, by Nagarajan et al [52] at 991 K for 0.0052 < xZr < 0.0267, by Turchanin et al [53] at 1022 K, for xZr < 5.49910 À3 , by Zubkov et al [54] at 1026 K, using an alundum crucible, by Decreton et al [55] at 996 K, using a graphite crucible.…”

“…An analysis of these studies lead to the hypothesis that the larger negative values may correspond to the formation of Al 3 Zr, which is faster than the dissolution of Zr in Al liquid. [55] The activity of Al in Al-rich liquid alloys has been determined with an electrochemical technique by Batalin et al [56] at 1123 K. The deduced values for the Zr solubility limit in Al(liq) being much larger than those reported in literature, these data are discarded.…”

Critical evaluation of experimental data of solution enthalpy of zirconium in liquid aluminum

“…They surprisingly did not mention any composition dependence of the solution enthalpy of zirconium in liquid aluminum. In our experiments [20], the measured heat flows effectively showed slight or no difference below and above the solubility whereas different thermal effects are expected corresponding to a dissolution process below the solubility and a precipitation of a solid phase (i.e. Al 3 Zr) above the solubility.…”

“…The experimental procedure and conditions of our tests are detailed in [20]. Some information are summarised here.…”

“…Numerous experimental determinations of solution enthalpies of zirconium in liquid aluminum were performed at temperatures around ≈1000 K [6][7][8][9][10][11][12][13][14] and at higher temperatures, above 1673 K up to 2045 K [15][16][17][18][19]. In the framework of a recent study of the Ag-Zr phase diagram [20] devoted to the determination of the standard enthalpies of formation of AgZr and AgZr 2 compounds, new values of zirconium solution enthalpy in liquid aluminum at 996 K have been obtained by our group. The comparison between our value and the previous ones highlights a rather good agreement (Table 1) even if one can consider the values somewhat dispersed.…”